April 17, 2003 52320207-1
CM 760 & CM 780
General Hydraulic Information---Chapt. 1
Hydraulic pumps---Chapt. 2
Cooling and Return circuits---Chapt. 3
Pilot Circuits---Chapt. 4
Tramming Circuits---Chapt. 5
Feed Circuit---Chapt. 6
Rotation Circuit---Chapt. 7
Air Compressor System---Chapt. 8
Dust Collector System---Chapt. 9
Rod Changing System---Chapt. 10
Electrical System---Chapt. 11
Drilling Information---Chapt. 12
General Information Page 1 Chapter 1 Working line Pilot line Drain line Enclosure line Squares or combinations of squares indicate valves
Circles indicate pumps, gauges or rotary actuators
Arrows indicate variability, adjustability or direction of flow
Check valve
Accumulator-gas charged
The diamond shape indicates fluid conditioners
Check valve-spring loaded
Hydraulic symbols
Basic building blocks
Spring--an arrow through the spring indicates an adjustment point
IN IN
IN Relief
Valve Pressure reducingvalve
Directional Control Valve
Three position four way valves
Flow control valves
Fluid conditioners A B P T A B P T A B T P A B T P A B P T A B P T Open center
Closed port Open centerOpen port
Closed center Open port Closed center Closed port Open center Closed port Open center Open port Pressure reducing/ relieving valve
Bypass type flow control with return
check valve Pressure &
temperature compensated
Filter w/ bypass Cooler
Fixed Variable Orifice
Hydraulic Symbols
Pressure & temperature compensatedRestrictive type flow control with return
General Information Page 3 Chapter 1
Hydraulic Symbols
Motors Pumps Fixed displacement unidirectional (Gear or Vane) Fixed displacement undirectional (Gear or Vane or piston)Variable displacement (piston)
Fixed displacement bidirectional (Gear Vane or Piston
bidirectional Variable displacement
unidirectional piston pump Pressure & flow compensated
(Load sensing)
Variable displacement bidirectional piston pump
Hydraulic Symbols
Valve operators
Vented Reservoir
Line to reservoir above fluid level
Pressurized
reservoir Line to reservoir below fluid level
Pressure switch Manual shutoff
valve Shuttle valve
Double acting cylinder Pressure gauge Temperature gauge
Lever Pilot operator Solenoid operator
Spring Cam or roller
General Information Page 5 Chapter 1
DEFINITION OF SYMBOLS
1. Working line: Any line used to carry working fluid. This includes
suction lines, pressure lines, and cylinder or motor connections and return lines.
2. Pilot line: Pressure used internally or externally to control valve
operation. The dashed line is used to differentiate pilot lines from others on a schematic.
3. Drain line: Drain lines are always connected to the reservoir and
are used for pump or motor case lines as well as a case drain connection for certain types of valves. Drain line pressure should typically be less than 5 PSI and be subjected to minimal spiking of the pressure.
4. Enclosure lines: This line will be used on a schematic around
more than one component symbol. This indicates that all of the items enclosed on the schematic are located in a single component on the machine.
5. Relief valve: Relief valves are used to limit maximum pressure to
protect a circuit. They may be pilot circuit relief valves or full flow system relief valves. Relief valves may be direct acting (spring over a poppet or spool) or pilot operated style (2-stage type). Pilot operated relief valves are more stable with high flows or where flows may vary greatly. The downstream side of any relief valve must be connected to low pressure or to the reservoir.
6. Sequence valve: A pressure operated valve similar to a relief
valve, which at its setting, directs flow to a secondary line while holding a predetermined minimum pressure in the primary line. Used in circuits that utilize a single directional valve to operate two functions in sequence.
7. Pressure reducing valve: A valve that limits pressure at its outlet
regardless of the inlet pressure. Frequently used to reduce system pressure to a lower PSI to perform a specific function.
8. Flow control valve, pressure and temperature compensated, restrictive type. A valve that is used to control the fluid flow through
a circuit. The pressure and temperature compensated designation mean that the regulated flow rate passed by the valve will remain constant regardless of system pressure and fluid temperature. A restrictive type valve is used with a variable pump system because the pump can match its output to the flow requirements determined by the flow control valve.
9. Flow control valve, pressure and temperature compensated, bypass type: This valve is also used to control flow through a circuit.
The bypass type valve is normally used with a fixed displacement hydraulic pump. Excess flow is bypassed to the reservoir by the
valve.
10. Orifice or restriction: An orifice is a restriction used for
controlling flow (speed). It can be of fixed size or variable (such as a needle valve). They are the simplest forms of flow control device.
11. Shuttle valve: A valve used to allow the highest of two pressure
sources to used downstream to perform a function. An example could be a hydraulic released traction brake system. The pressure developed on the pressure side of the circuit is used to release the brake via the shuttle valve.
12. Check valve: A valve that allows free flow in one direction but
blocks flow in the other. They can be equipped with a spring-loaded poppet that increases the cracking (opening) pressure of the valve. Some check valves are pilot operated that means they can be opened with pilot pressure to allow reverse flow.
13. Pumps and motors: The flow arrow pointing outward identifies
Pumps. An arrow drawn through the circle at an angle indicates the pump or motor is variable. If the flow arrow points inward the component is a motor.
14. Filters: A diamond shape indicates a fluid conditioning device,
the dotted line through the diamond identifies the device as a filter. The bypass is shown as either a spring loaded check valve or a relief
General Information Page 7 Chapter 1
15. Cooler or heat exchanger: The diamond shape with arrows
pointing outward indicates a cooler or heat exchanger. The symbol can represent a cooler that uses either air or water as the cooling medium.
16. Dual pilot operated check valve: Used as a load holding device
normally with a hydraulic cylinder. Utilizes two pilot operated check valves in the same valve housing. Pilot pressure from the inlet side of the valve is used to open the outlet check valve.
17. Counterbalance valve: Also a load holding device but a more
sophisticated valve than a pilot operated check valve. Commonly used in a dual configuration so pressure at the inlet of the valve opens the outlet. When lowering a load using a dual counterbalance valve the load cannot free fall. If load attempts to lower faster than the supply of incoming fluid the pressure at the inlet of the valve will drop and the outlet of the valve will begin to close. This creates hydraulic backpressure and slows the descent of the load. Counterbalance valves also can function as a relief valve. If the load is great enough, the valve will open and relieve the excessive pressure.
HELPFUL INFORMATION
1. Pascal’s Law: Pressure exerted on a confined fluid is transmitted undiminished in all directions and acts with equal force on all equal areas and at right angles to them.
2. The force in pounds exerted by a hydraulic cylinder can be determined by multiplying the piston area in square inches by the pressure applied (PSI).
3. To determine the volume (cubic inches) required to move a piston a given distance, multiply the piston area in sq. in. (π r) by the stroke length required (inches). Volume = Area x Length.
4. The weight of hydraulic fluid will vary with changes in viscosity. 55 to 58 pounds per cubic ft. covers the viscosity range from 150 SUS to 900 SUS at 100 degrees f.
5. Flow through an orifice or restriction will cause a pressure drop across that restriction. The more flow that attempts to pass through a given restriction the greater the pressure drop.
6. Hydraulic hoses are designated by their nominal inside diameter. With some exceptions, a dash number representing the number of sixteenth inch increments in their inside diameter indicates this.
Example: 1. 8/16 or –8 2. 16/16 or -16
7. One horsepower (HP) = 33,000 ft. lbs. per minute. One HP =746 watts.
General Information Page 9 Chapter 1 8. To find the HP required for a given flow rate at a known pressure use the formula:
Pump output HP = GPM x PSI x .000583 or, HP = GPM x PSI ÷ 1714 x Efficiency
Piston pumps in good condition are normally 90% to 95% efficient. Gear pumps in good condition are normally 80% to 90% efficient. 10. To find the uphole velocity of a drilling application use the formula:
144 x CFM: H2 - H1 = Up Hole Velocity (ft./ minute). H2 = hole diameter
H1 = Drill rod or stem diameter
11. To calculate the pressure required to open a pilot operated counterbalance valve use the formula:
Pilot Pressure = Relief Setting - Load Pressure ÷ Pilot Ratio 12. The relationship between torque and HP is:
Torque (in. lbs.) = 63205 x HP ÷ RPM or, HP = Torque (in. lbs.) x RPM ÷ 63205
13. To find pump volume when displacement (cu. in.) is known, use the formula:
Volume = RPM x Displacement ÷ 231 There are 231 cu. in. in one US gallon. 14. Area of a circle A = π r2 or A = .7845 d2
DUAL COUNTERBALANCE VALVE
Dual counterbalance (CB) valves are commonly used in load holding or load controlling applications. They are rated by PSI and PILOT RATIO. Examples might be 3000 PSI/ 10:1 pilot ratio, 5000 PSI/ 3:1 ratio. They are available in many different variations. The pressure rating of a CB valve is the pressure at which the valve will open when subjected to direct pressure. As an example; if an external load is applied to a hydraulic cylinder and causes the pressure in the cylinder to increase beyond the pressure rating of the CB valve, the valve will function as a relief valve and relieve the excess pressure to the return line. For this relief function to work it is necessary that the valve contain a motor spool which connects the two working ports to the return line when the valve spool is in neutral. The pilot ratio determines the pilot pressure required to open the valve. There is a simple formula for determining pilot pressure:
Pilot pressure = Relief Setting - Load Pressure ÷ Pilot Ratio If the values are inserted the formula looks like this:
Pilot Pressure = 3000 PSI - 0 PSI (no load) ÷ 10 (pilot ratio) 300 =3000
10
By making this simple calculation we can determine that 300 PSI is the pilot pressure required to open the valve. In a dual CB valve the pressure on the inlet side of the valve is used to pilot the outlet open. In a tram circuit for example, the sequence of events to tram the machine occur as follows:
1. The tram valve lever is moved from the neutral position. 2. The open valve allows fluid to move toward the CB valve and the tram motor.
General Information Page 11 Chapter 1 4. Pressure begins to build in the load sensing line. This line is connected to the load sensing connection on the main pump. The pressure signals the main pump to come "ON STROKE". As the pump comes on stroke more fluid is delivered by the pump to the tram valve.
5. At the CB valve fluid moves through the free flow check valve and toward the motor. The motor is a positive displacement device that means that fluid entering will cause the motor to attempt to rotate. As the motor tries to rotate any fluid already in the motor must be expelled and it must pass through the counterbalance valve. The outlet side of the CB valve will be closed initially and must be piloted open by pressure from the inlet side of the circuit.
In the example used above, the 3000 PSI ÷ 10:1 (the pilot ratio), the pressure at the inlet side of the circuit must be 300 PSI to pilot open the outlet. What this means is that if the motor attempts to rotate faster (as in tramming downhill) than the oil supply coming in at the inlet side of the CB valve, the pressure will drop. As the pressure drops toward 300 PSI, the outlet side of the valve will began to close and create a hydraulic restriction against the motor slowing it down and controlling its speed. This action prevents an overrunning load condition so the machine can be safely be trammed down hills. In a hydraulic cylinder circuit the action described above will prevent free fall of the load as the directional valve is opened.
In the tram motor circuit a spring set / hydraulically released static brake is used. The counterbalance valve is equipped with a shuttle valve that directs pressure from the working side of the circuit to release the brake. Usually the pressure required to release the brake is lower than the opening pressure of the CB valve thereby allowing the brake to fully release before the machine is allowed to move.
To review: The counterbalance valve has three major functions:
1. It provides load-holding capabilities when the cylinder or motor is in a static condition.
2. The valve protects the machine from overrunning load conditions and prevents free fall of hydraulic cylinders or downhill runaway of a machine.
3. The valve also provides for a specified minimum pressure so that external devices such as a holding brake can be released prior to movement of the load.
General Information Page 13 Chapter 1
3000 PSI
3000 PSI
Equipped with shuttle valve for brake release
All counterbalance valve will have a specified pilot ratio. This determines the pilot pressure required to open the outlet port of the valve.
LOAD SENSING
The Ingersoll-Rand ECM series crawler drills are equipped with load sensing hydraulic systems. Load sensing requires piston pumps that incorporate a dual control system. Dual control means that the pump can be regulated by either maximum pressure or by load generated pressure. The pumps used by Ingersoll-Rand are variable displacement axial piston units. Load sensing is one of the more efficient means of controlling a hydraulic system. This is because when no fluid is required to operate a machine function the pump pressure drops to the standby mode. The standby pressure will vary with different units. When the machine is in an operational mode, for example; drilling, the pump is required to operate at only the highest pressure required plus the standby pressure
In the load sensing system, valves are used that are proportional. This means that for any given handle position there is a corresponding flow rate. The drifter and feed circuits are equipped with controls that also regulate or limit pressure. All of the valves on the machine are closed center, this means that when a valve is in the neutral position pump flow is blocked. Internally in each individual valve section there is porting which directs load pressure (i.e.: actual pressure created by the load) toward the load sensing port on the pump control. This is frequently referred to as the signal pressure. The internal signal of each valve section is directed through a series of shuttle valves so that only the highest signal pressure reaches the pump load sense control.
With the unit running but no hydraulic functions being operated the pressure present at the outlet of the pump will be standby pressure. It is also important to know that pressure on the load sensing line will be 0 PSI. This is because when the valves are in neutral the internal load sensing circuitry is connected to the return or tank side of the circuit. We will use the rotation circuit to demonstrate circuit operation. If we mentally slow down the system function for this exercise it will help to understand the operation of the circuit. First, the valve lever for the rotation function is operated. This opens a flow path through the valve toward the rotation motor. When this flow path opens the first thing that happens is that the standby pressure being
General Information Page 15 Chapter 1 load sensing control on the pump constantly compares the actual discharge pressure with the pressure signal being received at the load sensing port. With all valves in neutral the load sensing line shows 0 PSI so the control only allows the pump to build to standby. The load sense control can be described as a variable compensator. As stated previously when the valve is moved the load sensing control recognizes that the outlet pressure is starting to drop. The control responds by causing the pump swash plate to come on stroke (move the swash plate to an angle so fluid is being moved). At this time fluid moving toward to rotation motor will began to generate some pressure. This pressure generates a pressure signal in the load sense signal line. As long as the pressure differential is less than standby the pump control will continue to increase flow until a PSI differential equal to the standby pressure is reached between the pump discharge and the load sense signal port. As an example, let us assume that the rotation valve is limited to 10 gallons per minute, as soon as the flow reaches 10 GPM no additional flow is delivered by the pump because the pressure differential between the pump outlet and the load is equal to the standby pressure. If the bit were to stall (become jammed) the pressure would began to climb. If this increase in pressure was allowed to continue unchecked, something would break. Because the pump is dual controlled, the pressure compensator will override the load sensing and limit system pressure to the maximum allowed which is the maximum pressure setting of the pump. Each individual circuit works the same as described above. The feed and drifter circuits have the additional feature of built in pressure control. This limits the pressure of these circuits to less than maximum pump pressure.
Load sensing and compensator Pump Control:
Standby compensator
Pressure compensator
LS
SHUTTLE VALVE
DUAL CONTROL
PUMP
(PRESSURE
COMPENSATED
AND LOAD
SENSING)
General Information Page 17 Chapter 1 Lx Ls A B Xb Xa Lx Ls A B Xb Xa "B" Supply to Valve "X" "L1" "S" DestrokeServo Stroking Servo A B Rotation Feed s or Ls
Load Sensing
MP 18 and MP 22 DIRECTIONAL VALVES
These valves are load-sensing pressure compensated proportional valves. They control the volume, direction of flow and maintain a constant flow regardless of changing load conditions. A valve may also have a feature that allows limits the pressure within its circuit to be limited to less than maximum pump pressure. Individual valves within the system may have different maximum flow rates. This is determined by the design of the directional spools as well as the style of compensator spool provided. Different compensator spring rates will also affect maximum flow.
Each valve section contains a compensator spool and spring, a primary shuttle valve and a secondary shuttle valve as well as the directional spool. These valves may be manually controlled, electrically controlled or pilot controlled. The valves used for the ECM 720 are pilot controlled. The compensator spool in each valve section regulates the flow. With the main spool in neutral, both the primary and secondary shuttle valves are vented to the return or tank. At the same time, standby pressure from the pump is directed to the bottom of the compensating spool and shifts the spool to the closed position. When the main directional valve spool is operated, the pressure generated by the load is directed via the primary shuttle to the spring end of the pressure-compensating spool. The compensating spool begins to move to the open position. Dependent on the pressure drop between the section compensator and directional spool opening, a specific volume now flows to the function being metered by the compensator spool. The load signal also simultaneously communicates to the secondary shuttle and on to the load-sensing valve on the pump causing the pump to come on stroke to deliver the flow required to satisfy the directional spool opening. Shifting the directional spool open to different positions creates an orifice of different size requiring more or less flow from the pump. The pressure limiting feature of the valve is used control hammer pressure, feed pressure and rotation pressure during rod changing. The valve compensator section can be used as a pressure-limiting device when connected to a pilot relief valve. This allows an individual valve section to operate at a limited pressure level less
General Information Page 19 Chapter 1 pressure is limited by the feed pressure control in the cab. A remote pilot relief valve controls the hammer pressure.
Drawing above is a typical MP style valve. The color coding indicates the various internal passages. This valve is equipped with a solid compensator and a motor spool. The valve is also pilot operated.
A
B
P
T
Ls
Lx
Pilot connection Pilot connection Remote pressure control connection used on some valves This orifice is onlyused with remote pressure control
feature
1
2 3
1. Primary shuttle valve 2. Secondary shuttle valve 3. Compensator valve
General Information Page 21 Chapter 1
Typical MP valves.
Manual MP style valve equipped with a hollow compensator. Note the location of the shuttle valve.
Pilot operated MP Style valve equipped with a solid compensator. This example is fitted with a compensator relief valve.
Primary Shuttle
Secondary shuttle valve Compensator Port relief valve
Typical MP22 pilot operated valve.
The inlet and outlet ports are located on the backside of the valve. The “LS” load sense port is on the same section as the inlet and outlet ports.
The “A” and “B” (working) ports are on top of the valve.
End Cap End Cap
Valve compensator section Main valve spool
General Information Page 23 Chapter 1
ECM 710/720 System Pressure Settings
Hydraulic System Settings
♦ Hydraulic Pump Compensator 3600 PSI (245 Bar) (Pump #1)
♦ Load Sense Standby Pressure 300 PSI (20 Bar) (Pump #1)
♦ Hydraulic Pump Compensator 3600 PSI (245 Bar) (Pump #2)
♦ Hydraulic Pump Standby Pressure 250 PSI (17 Bar) (Pump #2)
♦ System Relief Valve Setting 4200 PSI (289 Bar) ♦ Hydraulic Pilot Pressure 400 PSI (27 Bar) ♦ Rod Changer Pressure 2500 PSI (172 Bar) ♦ Dust Collector Pressure 2000 PSI (136 Bar) ♦ Maximum Feed Brake Pressure 300 PSI (20 Bar ♦ Rotation Pressure 1900 PSI (131 Bar (Rotation pressure in ARC mode) 1500 PSI (103 Barf) ♦ Cooling Fan Motor Speed Variable
(two separate units)
Air System Settings
♦ Main air system pressure Max 150 PSI (10.2 Bar) ♦ Service Air Pressure 100 PSI (7.3 Bar)
♦ Grease Pump Pressure 80 PSI (5.5 Bar ♦ Dust collector Pressure 50-60 PSI (4 Bar)
Fluid Capacities
♦ Hydraulic reservoir* 128 Gallons (485 Liters) ♦ Fuel Tank 155 Gallons (587 Liters) ♦ Cooling System 17 Gallons (64 Liters) ♦ Compressor 10 Gallons (38 Liters) ♦ Tram Final Drive Planetarys 1.8 to 2 Quarts (1.9 Liters) ♦ Engine Oil 29 Quarts (28 Liters)
*The hydraulic reservoir volume does not include refilling the hydraulic lines on the machine.
Hydraulic Pumps Page 1 Chapter 2
Hydraulic pumps
The CM 760/780 units are equipped with 5 hydraulic pumps. They consist of two axial piston, variable displacement pumps and three gear pumps. The piston pumps are of equal size and are mounted on pads at the rear of the engine. Both of these pumps are 5.18 in.3 (85cc). The left-hand pump supplies the left-hand tram circuit and the feed circuit. The right-hand pump supplies the right-hand tram circuit and the rotary head rotation circuit. The pump drives on the rear mounted gear box have a 1.3 : 1 speed increase.
The engine operates normally at 1800 RPM during drilling or high speed tramming although engine speed can be lowered through the use of a throttle control in the operator’s cab. The two piston pumps are operating at 1.3 X engine speed. This means that the pumps are turning at 2340 RPM.
Maximum pump output is 52 GPM (223 liters). Maximum pump pressure is 3600 PSI (248 Bar).
Both of the pump circuits are load sensing circuits. The standby pressure setting of both pumps is 250 PSI (17 Bar). Mounted on the auxiliary drive on the LH side (cab side) of the engine is a double gear pump. The double pumps provide fluid for the two cooler fan motors. The cooler circuits are discussed in chapter 3 of this manual. Just below the double pumps there is a single gear pump. This pump provides fluid for the drill positioning valve bank, rod changer valves and the dust collector. Following is the technical data regarding these pumps:
Double gear pumps (each unit) operate at 1.14 X engine speed. 2.54 In3 (41.6cc)
Volume @ 1800 RPM---22.5 GPM (85 LPM)
The single gear pump is mounted directly below the double pump also on the LH side (cab side) of the engine.
Single gear pump 1.37 In3 (22.5cc)
Volume @ 1800 RPM---15 GPM (57 LPM)
Piston pump adjustment procedure
NOTE: These or any adjustments should be done with the hydraulic system at normal operating temperature.
Left-Hand Pump
1. Install a 5000 PSI (350 Bar) test gauge at the pump outlet test port for the left-hand pump. The pump pressure test ports are located either adjacent to the shuttle valve assembly mounted just above the pumps or on the test panel found in the enclosure access door behind the cab.
2. Disconnect the feed stop solenoid on the mode valve located in the engine enclosure. (See chapter 4 for a description of the mode valve).
3. Place the drill/tram selector switch in the drill mode.
4. Start the machine and observe the test gauge. The reading on the gauge at this time should be standby pressure (250 PSI or 17 Bar). Set this pressure by adjusting the standby pressure control on the pump.
Hydraulic Pumps Page 3 Chapter 2 5. Have the operator or assistant place the feed control in the reverse position and depress the fast feed button. This will bring the left-hand pump on stroke at its maximum setting.
6. Adjust the maximum pressure on the maximum pressure adjustment to set the pump pressure. The pressure value is 3600 PSI (248 Bar).
Note: The pressure adjustments discussed here can be adjusted with the engine in the idle mode. To prevent the engine from going to high idle, disconnect the load sense pressure switch located directly above the pumps at the back of the engine.
Be sure to reconnect the feed stop solenoid after the adjustment to this pump are complete.
Right-Hand Pump
1. Install a 5000 PSI (350 Bar) test gauge at the pump outlet test port for the right-hand pump. The pump pressure test ports are located either adjacent to the shuttle valve assembly mounted just above the pumps or on the test panel found in the enclosure access door behind the cab.
2. Place the drill/tram control into the drill position.
3. Use the feed control and position the drill pipe under the rotary head so the breakout fork can be extended to lock the pipe. Loosen the top thread and extend the rod lock over the end of the pipe.
4. Check and adjust the pump standby pressure.
5. Place the rotation control in the cab into the reverse position. This will load the pump at maximum pressure.
6. Adjust the maximum pressure on the maximum pressure adjustment to set the pump pressure. The pressure value is 3600 PSI (248 Bar).
Cross section of variable displacement piston pump used on CM760/780.
There is a system protection relief valve located in the inlet section of each of the main valves. To check the setting of this relief valve, it is necessary to follow the same procedures as described above. The maximum pressure setting of the pump must be increased to the pressure setting of the relief valve. The relief valve is set at 4200 PSI (290 Bar). Disconnect the load sense pressure switch to prevent the engine from automatically ramping up to high idle. Load the pump as described in the appropriate section above. Slowly turn in the maximum pressure adjustment screw. Pay close attention to the sound of the engine, when the pump pressure reaches the relief valve setting the engine will start to lug. If this occurs at the proper pressure no adjustment is required to the relief valve. This procedure does not need to be performed each time the pressure is checked
Hydraulic Pumps Page 5 Chapter 2 1.3:1 speed increase Engine RPM=1800 "B" Supply to Valve 1.3:1 speed increase Engine RPM=1800 "B" Supply to Valve
Pressure Compensator 3600 PSI (248 Bar) Standby pressure 250 PSI (17Bar)
"X" "L1" "S" "X" "L1" "S"
Pressure Compensator 3600 PSI (248 Bar)
Note: The shaft speed of each pump is 2340 RPM Stroking Servo Destroke Servo Destroke Servo Stroking Servo 3 85 cc
Standby pressure 250 PSI (17 Bar)
5.18 in. 3
85 cc 5.18 in. Load sense pressure
switch (engine throttle) To Pilot Pressure-Reducing Valve
Left Hand Pump Right Hand Pump
Left-hand Tramming and Feed
Right-hand Tramming and Rotation
Hydraulic Pumps Page 7 Chapter 2
Auxiliary Fan pump circuits
As was stated previously in this chapter, the double gear pump supplies fluid for the two cooler fan circuits. The operation of each cooler circuit is the same. Because the pumps are positive displacement pumps, whenever the engine is operating, there is fluid delivered to each circuit. The operation of these systems is discussed in chapter 3.
Single Auxiliary Gear Pump
The single section auxiliary pump supplies fluid for the dust hood, centralizer and dust collector/pipe changing functions as well as fluid to the positioning valve in the cab. It is a fixed displacement gear pump that operates a 1.41 X engine speed. Its displacement is 1.37 in.3 (22 cc). Engine speed is 1800 RPM and that means that the pump is operating at 2538 RPM’s. Pump volume at 1800 engine RPM’s is 15 GPM (56 LPM).
3800 PSI (262 Bar)
3-section valve bank OPEN CENTER
1. Dust hood 2. Centralizers
7-section valve bank in cab (OPEN CENTER) 1.41:1
1.37 in. (22 cc)
3
Cooling & Return circuits Page 1 Chapter 3
Cooler Circuits
The cooler packages on the CM 760/780 consist of two separate cooler units. They are; the engine radiator, which is mounted at the boom end of the engine enclosure and the hydraulic oil cooler and compressor oil cooler, which is mounted at the rear of the enclosure. A hydraulically powered fan moves air through each cooler. The fans are mounted to the outside of the unit and pulls air through the cooler. This means that outside air is drawn through the power unit enclosure and exhausted by the cooler fan.
Each fan circuit is equipped with its own hydraulic pump and motor. A variable fan regulator valve controls fan speed.
General description of fan control circuit
The fan drive control assembly (FDCA) is an electrically controlled, normally closed proportional solenoid valve that provides a pilot pressure signal to the hydraulic fan drive system.
The system consists of an electronic module mounted on an aluminum manifold block containing a proportional solenoid relief valve. The electronic module receives temperature and auxiliary switch input signals and outputs a pulse width modulated signal to the valve producing a pilot signal that is proportional to cooling demand. The pilot pressure provides a signal to the primary flow control device that modulates the fan speed.
In this gear pump/gear motor fan drive system, a switch valve is mounted near the motor inlet. The switch valve is normally closed and opens to divert fluid away from the fan motor to the reservoir.
When cooling demand is high, the FDCA increases pilot pressure, signaling the switch valve to divert more fluid flow to the fan motor, thus increasing fan speed. As the cooling demand diminishes, the control decreases pilot pressure signaling the switch to “bypass” fluid away from the fan motor, thus decreasing fan speed.
The regulating switch for the engine cooling fan is located in the engine block. The switch for the compressor is in the discharge of the compressor. The switch for the hydraulic system is located in the hydraulic return manifold. These switches are variable resistance type switches. As the temperature of the fluid passing across the switch increases, the resistance across the switch decreases. This results in a higher output signal from the fan control module. The highest output is applied to the fan motor control valve. This results in a higher fan speed as the temperature increases.
Each of the temperature switches has a different control range. They are as follows:
Crack Full Open Shut Down Fan Start Full Fan Hydraulic 1400F 600C 160 0F 710C 180 0F 820C 160 0F 710C 170 0F 770C Engine 1800F 820C 203 0F 950C 220 0F 1040C 205 0F 960C 212 0F 1000C Compressor 1800F 820C 2050F 960C 2480F 1200C 2050F 960C 2350F 1100C Note that the shutdown temperature of each circuit is shown in the chart.
Maximum fan speed is approximately 2100 RPM. Because the fan control system will normally operate at less than maximum speed, fan speed tests should be done with the fan motor control module disconnected.
Note: Because the control valve used in this circuit is normally closed, the fan will default to its high speed setting in the event of an electrical fault.
The control module used in this circuit can only be tested using a computer-based program. In the event of a problem with the fan circuit contact the factory.
Cooling & Return circuits Page 3 Chapter 3
Fan control module
Shown on the following page is the hydraulic schematic for one fan control circuit. The circuit is the same on both of the cooler packages.
Variable Relief Valve
Cooler fan motor control module
Fluid supplied to second cooler fan control. Both circuits are identical
Cooler fan speed control manifold
"PP"
"P"
"T"
3000 PSI 204 Bar
Gear Motor 2.01 in.
33 cc.
3
1.14:1 speed increase
Both sections 2.54 in. (42 cc)
3
To return manifold Port Rm1 or Rm12
Cooling & Return circuits Page 5 Chapter 3
Return Circuit
The return circuit consists of the plumbing and components that are involved in returning the working fluid back to the reservoir. It is made up of the following:
1. Hydraulic reservoir
2. Return filters (dual canister with bypass) 3. Hydraulic oil cooler
4. Return manifold 5. Drain manifold
Return filters Hydraulic cooler Return manifold 140 F 0 60 C 0 10 PSI .7 Bar Reservoir
Tank breather & vacuum break
Hydraulic system fill pump By pas s 25 PSI 1.7 Bar 10 Mi cron Abs o lu te By pas s check v a lv e-150 PSI (10 Bar)
Case drain from piston pumps
Case drain from hydraulic drifter
Drain manifold 5 PSI Air pres su re from compressor
Cooling & Return circuits Page 7 Chapter 3
Return Manifold
Pilot Circuits Page 1 Chapter 4
Pilot Circuits
The drilling and tramming valves used in the CM760/780 are controlled by pilot pressure. Pilot pressure is supplied by either of the main hydraulic pumps through a shuttle valve to the drill/tram selector valve. The selector valve contains a pressure reducing valve that limits the pressure in the pilot circuit to 400 PSI (28 Bar). Incoming pressure from the main pumps may be as low as 250 PSI (17 Bar) or as high as 3600 PSI (248 Bar) under some circumstances. Remember, stroking either of the pumps will supply higher pressure to the valve.
Adjustment of the pilot pressure valve:
The drill/tram selector valve can be identified as it has two solenoid-operated cartridges and an adjustable cartridge. There is also a large hex plug that exposes a screen filter. There is also a quick connect test port on the valve body.
If the machine is running but neither the drill or tram functions are being used, the incoming pressure to the drill/tram selector valve is only 250 PSI (17 Bar). This means that it is necessary to stroke one of the main pumps to bring it on stroke and create a high enough pressure to enable the setting of the pilot pressure cartridge. This is easily accomplished by using the feed to lower the bit to the ground and leaving the feed lever in the forward or down position. Dial in the feed pressure to at least 500 PSI (34 Bar) to be certain that the pump outlet pressure is over 400 PSI (28 Bar).
DM
Pilot pressure to tram pilot valve
TC P DC DR 400 PSI 27 Bar 4 Test Pilot pressure to Feed and Rotation
pilot valves
Supply pressure from shuttle valve at main pumps
Drill/tram selector valve
Tramming:
When the tram position is selected, the tram solenoid becomes energized. This opens a flow path for fluid to be directed to the tram joystick control in the cab. When the joystick is operated, pilot pressure is metered to shift the spool in one or both of the tram directional valves. This action directs fluid from the pump to the tram motors. The tram control used in the CM760/780 is a single lever control. Moving the lever straight forward or backward, directs fluid through both tram valves simultaneously so the machine will operate in a straight line. Moving the lever to either side will cause the tracks to counter-rotate turning the machine.
Pilot Circuits Page 3 Chapter 4
Drilling:
When the drill position is selected, the drill solenoid is energized. The selector valve opens and directs pilot pressure to the drill control pilot controllers in the cab. There is one controller for the feed circuit and a second controller that operates the rotation circuit. The forward port of the rotation controller is connected to a pressure-reducing valve. This pressure-reducing valve is used to regulate the rotation pilot pressure to the forward control port of the rotation valve. The schematic on the following page shows the feed and rotation pilot circuits.
DM 8
Right forward tram Left reverse tram
Left forward tram Right reverse tram
Left turn poppet Right turn poppet Forward travel poppet Reverse travel poppet
Pilot pressure from drill/tram selector valve Port TC P T D C B A
Feed control in cab UP 2 Down 1 P T 2 1 P T
Rotation control in cab FWD
REV
Pilot pressure from Drill/Tram selector valve
Connections to feed valve in the engine enclosure Rotation speed control in cab Connection to reverse rotation port on valve Connection to forward rotation port on valve
Pilot Circuits Page 5 Chapter 4
Tramming circuits
The tramming system on the CM 760/780 consists of right and left-hand track drive units. These are planetarys driven by hydraulic piston motors. The tram valves are pilot operated valves and are controlled by a single lever joystick in the operator’s cab. See chapter 4 for information on the pilot circuit.
Each tram motor is equipped with a dual counterbalance valve that provides dynamic braking while tramming. The counterbalance valves on this unit are spool type CB valves. Earlier machine models used poppet style valves. The spool type valves allow for smoother starting and stopping of the machine. Each final drive has a brake. The brake is a spring set-hydraulic release unit and serves as a parking brake. This prevents movement of the machine while it is set up for drilling.
As the tram valve is shifted the fluid it supplies is directed to the motor through the inlet check valve which is found in the counterbalance valve manifold. Pressure begins to build at the motor inlet port but the motor cannot rotate because the brake is still in the set position. As stated in the previous paragraph the brake is a spring set-hydraulically released static unit. At the same time fluid cannot leave the motor because the outlet of the motor is blocked by the counterbalance valve spool. When the pressure builds high enough the brake will release. The motor still cannot rotate until pilot pressure in the counterbalance valve increases to shift the spool to an open position. It is important to know that the brake release pressure is always lower than the counterbalance valve setting. The brake releases, the counterbalance valve spool shifts to the open position and the machine will begin to move.
NOTE: simply stated, pressure building at the inlet of the motor is used to open the outlet of the motor. The counterbalance valve accomplishes this task.
The machine is equipped with a drill/tram selector switch. The tram control is a single joystick control. The control joystick is a variable pressure pilot controller. Full speed control of the units is assured by
Tram Circuits Page 2 Chapter 5 There is button located in the upper portion of the control lever that operates the horn. When the selector switch is placed in the tram position, pilot pressure at 400 PSI (27 Bar) is supplied to the tram joystick located in the cab.
Turning the unit while tramming is accomplished by moving the joystick control either right or left while tramming. Moving the lever forward and to the left will cause the machine to move forward while executing a left turn. Moving the lever forward and to the right will cause the machine to move forward while executing a right turn. Moving the joystick directly to the left or right position will cause the unit to counter rotate in that direction. If the joystick is moved to the rear for reverse tramming and at the same time moved to the side to execute a turn it is important to note that the unit will turn the opposite direction in which the lever is moved.
A Pa B Pb A Pa B Pb Left Tram Right Tram A B A
B Left tram motor
Right tram motor Pilot pressure fom
drill/tram selector Tram pilot valve
D
C
A
B
Tram Valves-42 GPM (158 LPM) Maximum flow
Backup Alarm
Switch Final drive
74.3:1 reduction Tram Motors 5.05 in. /rev. 83.6 cc/rev. 3 400 PSI (27 Bar)
Flow from Left-hand Pump
Flow from Right-hand Pump
NOTE: The left-hand tram valve is one section of a two-valve stack
that includes the feed valve. The right-hand tram valve is one section of a two-stack valve that
Tram Circuits Page 4 Chapter 5
FEED SYSTEM
The feed system contains the following components:
1. Feed control joystick in the operator’s cab. This control is a
pilot control valve. Pilot pressure is regulated depending on the position of the control lever. The control lever also is equipped with the push button used to activate fast feed.
2. Feed pressure control located on the drill console in the cab. This control is a pilot relief valve, which sets the maximum
feed force applied to the bit.
3. Feed valve located in engine enclosure.
4. Feed motor counterbalance and brake valve. The valve is
located adjacent to the feed motor on the drill guide. The manifold contains the counterbalance cartridges and a pressure reducing cartridge valve for limiting the pressure applied to the feed brake.
5. Feed motor and brake assembly. The motor is a radial piston
unit with integral brake unit. The feed motor directly drives the feed chain, no intermediate gearing is used. The displacement of the feed motor is 64.3 in.3 (1054 cc).
Operation of the feed circuit:
When the Drill/Tram selector switch is placed in the drill position, pilot pressure at 400 PSI (27 Bar) is directed by the drill tram selector valve to the joystick controls found on the operators seat arms. The feed joystick is a proportional pilot control valve. Moving the joystick lever forward activates down or forward feed, moving the lever back activates retract or reverse feed. Pilot pressure developed by moving the joystick is directed to the mode valve. When slow feed is being used, pilot pressure passes through the mode valve and shifts the slow feed spool to the appropriate position. When depressing the fast feed button activates fast feed, both of the fast feed solenoid valves located in the mode valve are activated. This directs the pilot pressure generated by the joystick also to the fast feed valve spool. When using fast feed, both
Feed System Page 2 Chapter 6 feed valves are activated. Control of the fast feed is still proportional due to the ability of the feed joystick to regulate pilot pressure.
When drilling, only the slow feed valve supplies the slow feed fluid. From the slow feed valve, fluid is directed to the Stratasense manifold. The operation of the Stratasense manifold is discussed in Chapter 6 of this manual. It is important to remember that the slow feed valve is proportional and is pressure limited by the feed pressure control in the cab. This means that even though the slow feed valve has a 5 GPM (19 LPM) maximum flow rate the flow actually supplied will be only enough to maintain the feed pressure as set in the cab. When fast feed is used, the fluid from the fast feed valve is directed to the feed motor downstream of the Stratasense feed control spool.
The last component of the feed circuit is the feed motor and counterbalance valve. These components are mounted as the base of the drill guide. The feed motor is a Poclain 47.3in.3 (775cc) radial piston unit with and integral brake. The Brake is a spring set/hydraulic release unit. The brake is 50% released at 100 PSI (7 Bar) and fully released at 170 PSI (11.5 Bar).
The counterbalance valve package includes two (2) cartridge valves set at 3000 PSI (204 Bar). The opening pilot ratio of these valves is 10:1. The purpose of the counterbalance valves is the load-holding capability. The brake valve located in the counterbalance manifold is set at 300 PSI (20 Bar). There is a quick connect test port located on the manifold for checking and adjusting the brake release pressure. It should be noted here that the brake unit on the feed motor is rated for 475 PSI (32 Bar). Operating the feed with a brake valve setting higher than the maximum pressure capability will result in brake housing failure.
ADJUSTMENTS-FEED COUNTERBALANCE & BRAKE VALVE
The operator has full control of the feed pressure while drilling. The feed pressure adjustment is located on the tram console to the right of the drill/rotation control joystick. The other components that may require adjustment are the feed counterbalance valves and brake valve. To adjust the counterbalance valves:
1. Use the feed lever and lower the drifter to the bit is on the ground or the drifter to the bottom of the drill guide. This is very important so the drifter cannot fall during the adjustment procedure.
SERIOUS INJURY CAN RESULT IF THE DRIFTER FALLS UNCONTROLLED.
2. Disconnect the feed motor working lines from the motor and join these two hoses together with a tee fitting. Connect a 1000 PSI (150 Bar) gauge to the open port of the tee. Cap the motor ports to prevent dirt from entering the motor.
3. Start the engine and place the feed valve in the forward position. Observe the test gauge. If the counterbalance valve is properly adjusted, the gauge should indicate 300 PSI (20 Bar). If not, locate the counterbalance valve cartridge opposite the FF (forward feed) port. Remove the dust cap. To lower the pressure, turn the adjustment screw in (clockwise). To increase the pressure, turn the adjustment screw out (counter clockwise). Be sure the retighten the locknut.
4. To adjust the reverse feed counterbalance valve, have an assistant hold the feed lever in the reverse position and repeat the previous paragraph in reverse. If no help is available, the two counterbalance cartridges can be exchanged and use the same procedure as described in paragraph 3. Reconnect the lines
To adjust the brake valve, lower the drifter so either the bit is on the ground or the drifter is at the bottom of the drill guide.
1. Remove the brake line from the feed motor brake unit. Install a 1000 PSI (150 Bar) gauge in the end of the hose. Cap the open brake port. The brake valve test port may also be used for this adjustment.
2. With the engine running and the drill / tram selector switch in the drill position, place the feed lever in the down feed position. Check the feed pressure gauge and adjust the feed pressure to 1000 PSI (68 Bar) or higher. Observe the test gauge. It should indicate
Feed System Page 4 Chapter 6 300 PSI (20 Bar). If it does not, remove the dust cap from the feed brake pressure-reducing valve. Turn the adjustment screw out (CCW) to decrease the pressure or in (CW) to increase the pressure. Retighten the locknut and replace the dust cap. If removed replace the brake hose.
Feed Motor, Brake and Counterbalance Valve
Brake
Feed Motor
Brake valve
Feed System Page 6 Chapter 6
Feed counterbalance and brake valve
300 PSI (20 Bar) FVb FVa 10:1 Pilot Ratio 3000 PSI (200 Bar) 3 Spring set-hydraulic release brake
Feed Circuit
Feed Motor 64.3 in. (1054 cc) 17 GPM 64 LPM 5 GPM 19 LPM A B A B Remote P Ls T Feed Left Tram Ls T P XB Up XA Down PCV2 PCV1 CFV XB XA 1 2 3 4 5 6 7 8 9 F R RRP DT T CRV PCV31. Feed up synchronizing valve 2. Feed down synchronizing valve 3. Fast feed solenoid valve
4. Feed travel stop solenoid valve
5. Forward rotation torque limit relief valve 6. Reduced feed pressure up relief valve
7. Solenoid valve that selects reduced up feed or normal up feed 8. Fast feed solenoid for maximum up feed pressure
9. Pilot valve for maximum reverse rotation pressure
2500 PSI (172 Bar)
1800 PSI (124 Bar)
Port identification (mode valve)
Port T is connected to the #1 port of the feed pressure relief valve in the cab
Port DT is connected to the drain manifold.
Port F is connected to the forward feed pilot port of joystick in the cab.
Port R is connected to the reverse feed pilot port of the joystick in the cab.
Port RRP is connected to the reverse rotation port of the rotation joystick in the cab.
Port PCV3 connects to the reverse pilot port on the rotation valve. Port CRV connects to the remote pressure control port of the rotation valve.
Port PCV1 connects to the reverse or up feed pilot port of the feed valve.
Port PCV2 connects to the forward or down feed pilot port of the feed valve.
Port CFV connects to the remote pressure control port of the feed valve.
Chapter 9 Page 8 Feed Circuit
1. Adjusting the feed counterbalance valve and brake valve.
1. Use the feed lever and lower the drifter to the bit is on the ground or the drifter to the bottom of the drill guide. This is very important so the drifter cannot fall during the adjustment procedure.
SEVERE INJURY CAN RESULT IF THE DRIFTER FALLS UNCONTROLLED.
2. Disconnect the feed motor working lines from the motor and join these two hoses together with a tee fitting. Connect a 1000 PSI (150 Bar) gauge to the open port of the tee. Cap the motor ports to prevent dirt from entering the motor.
3. Start the engine and place the feed valve in the forward position. Observe the test gauge. If the counterbalance valve is properly adjusted, the gauge should indicate 300 PSI (20 Bar). If not, locate the counterbalance valve cartridge opposite the FF (forward feed)
port. Remove the dust cap. To lower the pressure, turn the adjustment screw in (clockwise). To increase the pressure, turn the adjustment screw out (counter clockwise). Be sure the retighten the locknut.
4. To adjust the reverse feed counterbalance valve, have an assistant hold the feed lever in the reverse position and repeat the previous paragraph in reverse. If no help is available, the two counterbalance cartridges can be exchanged and use the same procedure as described in paragraph 3. Reconnect the lines
To adjust the brake valve, lower the drifter so either the bit is on the ground or the drifter is at the bottom of the drill guide.
1. Remove the brake line from the feed motor brake unit. Install a 1000 PSI (150 Bar) gauge in the end of the hose. Cap the open brake port. There is also a test port on the counterbalance valve/brake valve manifold. This can be used to perform this adjustment.
2. With the engine running and the drill / tram selector switch in the drill position, place the feed lever in the down feed position. Check the feed pressure gauge and adjust the feed pressure to 1000 PSI (68 Bar) or higher. Observe the test gauge. It should indicate
300 PSI (20 Bar). If it does not, remove the dust cap from the feed brake pressure-reducing valve. Turn the adjustment screw out (CCW) to decrease the pressure or in (CW) to increase the pressure. Retighten the locknut and replace the dust cap. Replace the brake hose.
Rotation Circuit
One section of a double section MP18 valve (the other section is for right-hand tramming) controls rotary head rotation. During drilling the fluid supplied to the rotation comes from the right-hand hydraulic pump. As covered previously in this manual, the rotation pump is a 5.18 in.3 (85-cc) displacement unit. The pump displacement is variable with load sensing control. This means that the rotation valve is a load-sensing valve. The valve has a maximum flow rate of 33 GPM (125 LPM). The valve also has a pressure compensated flow controlled inlet. Fluid flow to the rotation motor is determined by the position of the main spool in the valve. The main spool is shifted by pilot pressure and by varying the pilot pressure the position of the spool can be changed. Pilot pressure can be adjusted in the cab to regulate rotary head forward rotation speed, which is necessary so that rotation speed always remains the same for drilling. A single lever pilot controller located on the right-hand armrest of the operator seat controls rotation functions. Moving the lever forward activates the forward rotation; this is the normal drilling position. When the control lever is moved to its rear position, reverse rotation is activated. When the rotation lever is moved to the forward position, and drilling is taking place, pilot pressure from the forward rotation poppet is being directed through the speed control pressure-reducing valve. If the rotation lever is all of the way forward, the pilot pressure being delivered to the pressure-reducing valve will be 400 PSI (27 Bar). The pressure-reducing valve lowers the incoming pilot pressure to deliver a lower pressure to the pilot operator port on the rotation valve. This means that the rotation spool only opens proportionally to the level of pilot pressure it receives. When the unit is placed in the pipe changing mode, a solenoid valve opens and bypasses pilot pressure around the pressure-reducing valve directing full pilot pressure to the rotation spool, it opens fully the rotation speed is at its maximum level. By setting the feed speed during pipe changing the coupling and uncoupling can be synchronized to prevent undue wear to the threads on the pipe.
The rotation circuit is torque or pressure limited in the forward mode. This pressure is set on the mode valve. Reverse rotation pressure is limited only by the pressure compensator on the right-hand pump.
Rotation Circuit Page 2 Chapter 7 The rotation valve is equipped with a remote pressure control port. This port is connected to the remote relief valve. During drilling this relief valve is limiting forward rotation pressure. Forward rotation pressure is normally set at 2500 PSI (172 Bar). When the rotation control is placed in reverse, a pilot controlled on/off valve is closed. This action isolates the remote relief valve out of the circuit and the pump compensator then limits the circuit pressure. The pressure compensator is set at 3600 PSI (248 Bar). This means that there is more pressure available for breaking out the pipe thread than that developed during makeup and drilling.
Adjustment:
To adjust the rotation torque limit valve it will be necessary to stall the rotation. This can be accomplished by closing the centralizer on the bit. Place the drill/tram switch in the drill mode. Move the rotation joystick to the forward position. This action will stall the rotary head and cause the rotation circuit to develop the maximum forward pressure. The standard setting of the rotation is 2500 PSI (172 Bar).
Lx Xb Xa Ls A B Xb Xa 42 GPM 158 LPM 124 LPM33 GPM Remote port PCV2 PCV1 CFV F R RRP DT T CRV PCV3 2500 PSI (172 Bar) 1800 PSI (124 Bar)
Mode Control Valve
Rotation Valve Right-hand Tram Valve
1
2
Pilot pressure from Drill/Tram Selector
Forward Rotation Reverse Rotation
Rotation Speed Control Rotation ControlJoystick
Rotation Torque Limit Relief Valve
To Rotary Head
P
T
Rotation torque limit pilot valve
Rotation
Circuit
Rotation Circuit Page 4 Chapter 7
Rod Lock Sleeve System
To facilitate the pipe handling system on the CM 760/780, the rotary head is equipped with an extendable sleeve that slips over the square end of the drill pipe. This is required when removing the pipe from a drilled hole. At this time, the pipe joint under the rotary head is loosened slightly so the sleeve can be extended of the square end. The breakout fork is extended to engage the lower pipe and the joint is loosened and uncoupled so the pipe can be place back into the carousel. At this time full reverse torque can be applied to the joint through the rod lock sleeve.
There is a constant pressure maintained on the sleeve retract side of the sleeve. This pressure is supplied through the auxiliary control valve. This is a manifold valve assembly. The valve is located in the engine enclosure behind the operator’s cab. The rod lock sleeve section of the manifold is essentially separate from the other functions of the manifold. . Pressure is supplied to the rod lock sleeve from the auxiliary pump. This pressure is directed from the outlet of the pump before its connection to the three-section valve. This pressure is directed to a pressure-reducing valve located in the manifold. This valve is normally set at 450 PSI (31 Bar). Because the auxiliary pump circuit always has a residual pressure of 500 PSI (34 Bar), there is always enough pressure to operate the rod lock sleeve.
In operation, there is pressure directed to the bottom of the sleeve. The sleeve contains a .030 orifice that constantly bleeds fluid to the top side of the sleeve. During drilling the top of the sleeve is connected to return. This bleed prevents the fluid in the sleeve area from overheating and also maintains constant pressure to keep the sleeve from extending. When the sleeve is extended to remove pipe from the hole, 450 PSI is directed by the control valve to the top of the sleeve. Because of the greater area of the top of the sleeve compared to the bottom of the sleeve the sleeve extends.
1500 PSI A2 B2 A5 B5 A4 B4 100 Bar P T A3 B3 IP .030 Air Connection FR RR Rotary Motor Rod Lock D RLE RLR Chain Wrench Carousel Rotation
Rear Jack (opt)
Ground Winch (opt)
450 PSI 31 Bar 3400 PSI 234 Bar EP RLR1 Pressure from Auxiliary Pump
Pressure in this line will normally be at least 500 PSI (34 Bar) which is adequate to operate the rod lock sleeve.
ARC/DC Valve
Rotation Circuit Page 6 Chapter 7
DDRH Rotary Head (early style)
Early CM 760 and CM 780 units were manufactured with the latest version of the DDRH rotary head. This style head is fitted with a top mounted air swivel arrangement. The rotary motor drive system is a direct drive 64 in.3 (1048 cc) radial piston motor. The rotary head uses the breakout sleeve system for pipe thread breakout. The air swivel is fitted with chevron packing. A hand-operated grease gun is required to keep the packing loaded. The grease fitting in the packing housing does not have a built in check valve so excessive grease pressure cannot be applied.
Note: Do not use standard grease fittings in place of the point indicated with the red arrow. Remove the spring and ball from the fitting so excessive grease pressure cannot be applied to the packing.
Spindle adapter
The spindle adapter is the replaceable part found in the end of the rotary head hollow shaft. It has 3 1/2 API male thread to engage the spindle and the female thread will either be 2 or 2½ Z thread.
Replacing the Spindle Adapter
The spindle adapter is a wear part that will require replacement. This can be accomplished with the rotary head at the bottom of the drill guide and the guide vertical. Allow some space below the lowered head for removal of the parts. Blocking should be installed under
the rotary head mounting plate for additional safety.
Removal and replacement of the spindle adapter requires the removal of the front housing and rod lock sleeve. This will expose the adapter, which is threaded into the end of the rotary head spindle.
1. Vent the air pressure from the hydraulic tank by removing the pressure gauge temporarily. Apply a vacuum to the vent port on the hydraulic tank if available. Remove all of the hydraulic lines from the lower section of the rotary head. Plug, cap and tag all open hoses and connections. Remove the rod lock housing by removing the 12mm socket head screws from the bottom. There are two threaded holes that can be used for drawing the front housing loose. The rod lock sleeve may come out with the lower housing so be careful, as these parts are heavy. With the lower housing and rod lock sleeve removed, the flats on the spindle adapter are now accessible.
2. The rotary head spindle must be locked before the adapter can be removed. Use capscrews from the rod lock housing to install the locking plate (52129111). The locking plate slips over flats machined into the spindle. The spindle may need to be rotated to align the threaded holes in the bearing housing with the locking plate.
3. Attach the appropriately sized “J” wrench to the breakout cylinder to loosen the adapter. The breakout cylinder must be extended to loosen the adapter. The locking plate may need to be indexed
Rotation Circuit Page 8 Chapter 7 relative to the spindle adapter to allow for maximum torque to be applied to the “J” wrench.
Note: It may be necessary to increase the extend pressure for the breakout cylinder to loosen the adapter.
4. After the old adapter has been removed, thoroughly clean the API threads in the end of the spindle as well as on the new adapter.
5. When installing the new adapter, use LOCTITE primer #T747 and coat the threads with LOCTITE #680 (cpn #51948727) thread lock. Install the adapter into the spindle and torque to 4500 lb-ft. (6100 Nm.) If the breakout cylinder is used for the retorque of the spindle adapter, it will be necessary to increase the pressure to the retract side of the cylinder to 2500 PSI. (175 Bar) to develop an adequate amount of torque.
Note: the breakout cylinder will deliver maximum torque when it is almost fully retracted.
6. Allow ample curing time for the LOCTITE #680. If the primer is used, the bond will be partially cured in 5 minutes and fully cured in 4 to 6 hours. If the primer is not used the partial cure time is extended to 30 minutes.
7. After the replacement of the spindle adapter is complete, reassemble the rod lock and front housing to the rotary head. Use care during the installation process to prevent damage to the rod lock seals. Reconnect all hydraulic lines.
Replacing the Chevron Air Packing
To replace the chevron air packing the following steps should be followed:
1. Remove the six (6) socket head 3/8” cap screws that secure the gooseneck to the air swivel.
2. Remove the ten (10) socket head M16 cap screws the secure the base of the air swivel housing to the rotary head.
3. The chevron packing can then be removed from the swivel housing.
4. Inspect the washpipe for wear and/or looseness on the threads at the end of the spindle.
5. The thread on the end of the spindle is a left-hand thread. If retightening is required, apply LOCTITE as described on page 14 or page 27 of this section of the manual. A special tool cpn 52291176 is required for this operation.
6. When the LOCTITE is applied, be sure to allow ample curing time to prevent loosening prematurely.
7. Install the new chevron packing as shown on the drawing on page 28 of this section.
8. Reinstall the swivel housing and gooseneck after grease has been applied to the new chevron packing.
9. Grease both grease fittings on the swivel before restarting the unit.
Replacing the spindle and/or spindle bearings
The drawing on page 11 can be used to identify various parts of the rotary head.
1. Remove the rod lock assembly and swivel housing as described previously in this section.
2. Unthread the washpipe from the end of the spindle. This will require the special tool cpn 52291176. NOTE: The threads in the washpipe are left-handed. Remove the seal plate directly under the washpipe.
3. Remove the twelve (12) M16 socket head capscrews that retain the hydraulic motor assembly to the bearing housing. Set the motor assembly aside being careful to keep the assembly clean.
Rotation Circuit Page 10 Chapter 7 4. Remove the twelve (12) M16 socket head capscrews that secure the top bearing plate. NOTE: The bearing plate is designed to provide the proper preload on the spindle bearings when tightened down.
5. At the bottom of the bearing housing, remove the eight- (8) M12 capscrews that retain the lower seal plate. Remove the seal plate from the housing.
6. Remove the spindle from the bearing housing. The top bearing cup is a slip fit into the housing.
7. If the bearings (cups and cones) are to be reused, carefully remove the cones from the spindle. These will have to be pressed onto the new spindle.
8. If the bearings are being replaced, the cone for the lower bearing will have to be pressed into place.
9. To reassemble the head, reverse the disassembly procedure. The washpipe and spindle adapter must be installed with LOCTITE. Use LOCTITE primer #T747 and coat the threads with LOCTITE #680 (cpn #51948727).
The torque specifications for the fasteners used in the rotary head are as follows:
M12 (grade 10.9) (lubricated threads)---55 lb-ft or 100 Nm. M16 (grade 10.9) (lubricated threads)---138 lb-ft or 250 Nm.
