THE STEERING SYSTEM
147 In the intermediate position, the piston
147 In the intermediate position, the piston returns into the cylinder and begins to displace the fluid accumulated there. At its lowest point, the piston occupies almost the entire cylinder. The expulsion of the fluid through the discharge port is now complete. The piston again rises from this position for the suction stroke. The repetition of
The pump control shaft enters at the bottom, connected to the tilting box. The centering spring and its actuating spindle, against which the top end of the pump control shaft bears, are contained in the tall, pipe-like housing screwed onto the top of the power-driven Waterbury A-end pump.
these movements in sequence by all of the pistons results in a smooth
nonpulsating flow of hydraulic fluid.
In normal operation, the hydraulic power used by the steering system is developed by a Waterbury size 5 A-end pump. It is driven by a 1.5-hp electric motor at a constant speed of about 440 rpm. The pump turns in a clockwise direction as viewed from the, motor end of the shaft. The pump's speed is
constant; only the direction and angle of the tilting box change. It is these that determine the amount of oil that is pumped into the system to move the rudder and the direction in which it is pumped.
b. The control cylinder. The function of the control cylinder is to translate the movement of the main steering wheel, as the steersman turns it left or right, into a corresponding upward or
downward motion of the control shaft, thereby changing the position of the tilting box in the motor-driven
Waterbury pump. This, in turn, varies the stroke of the pistons inside the motor-driven pump. It also determines the quantity and direction. of flow of the oil that is pumped to the main rams.
In this manner it controls the output of the motor-driven Waterbury pump in obedience to the actions of the steersman when steering by normal power.
The control cylinder assembly consists of a pair of small hydraulic cylinders opposed and axially in line, having in common a single plungers which slides between and through the cylinders.
Bell-crank linkage connects this plunger to the tilting box.
13B3. The steering ram cutout manifold. The steering ram cutout manifold consists of a multiple-port housing containing nine valves built into the body, and eight ports which connect the main rams to the sources of hydraulic power.
The manifold is so arranged that the four center valves are power cutouts to the port and starboard rams from the main steering pump. The forward set of two valves and the after set of two valves are hand and emergency cutouts to the port and starboard rams when the power is furnished from the control room. A bypass valve at the top central part of the manifold, if opened, would bypass the main steering pump by connecting both sides of the pump together. This bypass normally is shut.
The manifold has two connections at the top which connect the manifold with the motor-driven Waterbury A-end pump. Of the lower four connections of the
manifold, the two in the center are connections to the starboard ram. The remaining two connections, one forward and one aft on the lower part of the manifold, are hand and emergency connections from the control room.
The connections from the manifold to the port ram are at the foremost and
aftermost part of the manifold. All the valves have attached name plates indicating their purpose.
The main cylinder ram assemblies, usually referred to as the rams (port and starboard), transform hydraulic power into mechanical power to move the rudder. Each consists essentially of a pair of hydraulic cylinders opposed and
On all later classes of submarines, the control shaft that extends through the Waterbury A-end power-driven pump has the centering spring attached to one end of the control shaft and the control cylinder on the opposite end.
axially in line, having in common a plunger or ram that slides between and through them and a hydraulic port at each end, into which oil is admitted to move the rams forward or aft. The plunger has at its center a heavy yoke forged
148
Figure 13-2. Steering stand.
149
integrally with it; the yoke has a hole pressures developed by the motor-driven
drilled in it to take the inboard
connecting rod which is locked into it at this point by heavy lock nuts, one on each side of the yoke. The inboard connecting rod slides through the bearings. Oil leakage past the plunger is prevented by the packing. The entire ram assembly is bolted to the
framework through the brackets.
Mounted at the forward end of the ram is the mechanical rudder-angle
indicator pointer showing the angle of rudder deflection on the indicator dial, which is graduated in degrees. An electrically operated rudder angle transmitter is located on the other ram.
It transmits the angle of deflection electrically to a rudder angle indicator on the instrument hoard in the control room.
13B4. The steering stand. The
hydraulic power that moves the rudder is directed by the steersman from the steering stand, an assembly which contains the control equipment for all three methods of steering, Power, Hand, and Emergency. (See Figure 13-2.)
a. The steering stand pump. Since, in operation by normal power, it is the direction of the motor-driven
Waterbury A-end pump tilting box that determines which way the rudder moves, and since the position of this tilting box is controlled by the
movement of oil in the control cylinder, it is clear that to steer the submarine, some device is needed which will drive that oil one way or the other as desired.
The mechanism must be one that will respond readily to the steersman's touch, yet control accurately the powerful
Waterbury A-end pump. Such a device is the steering stand pump, the steering stand's main unit. The steering stand pump is actually a hand-operated Waterbury A-end pump. A bracket is fitted externally to it and the pump control shaft so that its tilting box always tilts in the same direction, though its angle, that is, the degree of tilt, may be changed. Consequently, the flow of oil depends solely on which way its shaft is rotated. If a large handwheel is fitted to this shaft, the ports of the pump
connected to opposite ends of the control cylinder, turning the wheel left or right, will then pump oil to one or the other end of the control cylinder, which in turn tilts the tilting box in the motor-drivers Waterbury A-end pump, thus moving the rudder left or right. Therefore, turning a wheel fitted to the shaft of the steering stand pump will steer the submarine.
b. The main steering wheel. This wheel is mounted vertically at the after end of the steering stand. It is used for both
POWER and HAND steering.
As hand steering requires greater effort, a retractable spring handgrip is built into the rim. During power steering, this handgrip may be kept folded in. A
spring-loaded locking pin is built into the hub; when pulled out, it allows the main steering wheel to be disengaged from its shaft.
This is provided to prevent the main wheel from spinning heedlessly when the submarine is being steered from the conning tower.
C. OPERATIONS
13C1. Power steering. When steering by power, (See Figures 13-3 to 13-7.) the following conditions are obtained:
a. The change valve in the control room is set for power steering.
b. The steering stand pump stroke control lever may be in any of the possible positions. Experience has indicated, however, that the most satisfactory position is with the pump at approximately three-quarters of a stroke.
c. The main steering motor is running.
To illustrate the operation of the steering gear when steering by power, assume that it is desired to move the rudder from amidship to hard over left rudder. The steersman turns the steering wheel to the left, thereby turning the shaft of the steering stand pump which delivers oil through the change valve and one of the control cylinder lines to the after control cylinder; and oil from the forward control cylinder is forced back through
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Figure 13-3. Change valve.
the other control cylinder line to the suction side of the pump.
Delivery of oil to the after control cylinder moves the control ram forward, thereby moving the main pump tilting box control shaft downward from neutral toward full stroke. This puts the tilting box in a position to deliver oil from the port side of the pump through the relief and cutout manifolds. Oil from the manifolds enters the lines to the forward starboard ram and the after
Figure 13-5. Shifting steering control.
For the purpose of maintaining the pump control shaft in neutral position when it is desired to hold the rudder angle constant, a spring-loaded centering device is mounted adjacent to the pump. This device consists of a compression spring enclosed in a cylinder and mounted on a spindle in such a way that if the spindle is moved in either direction, the spring is compressed and tends to return the spindle to its normal position. The spindle is connected to a lever mounted on the rocker shaft which operates the levers to the pump and control cylinders
port ram, moving the rudder to the left, while return oil from the forward port and after starboard ram is delivered to the starboard side of the pump or the suction side.
Figure 13-4. Stroke adjuster.
respectively.
When the desired position of the rudder is reached, the steering wheel must be brought
Figure 13-6. Steering wheel.
151
Figure 13-7. Starting control.
back to its original position to stop rudder movement, since there is no follow-up mechanism in this steering gear.
The power steering gear is protected by two relief valves, one installed in either side of the main relief manifold.
13C2. Hand steering. When steering by hand, (See Figures 13-8 to 13-12.) the following conditions are obtained:
Figure 13-9. Change valve.
is set in its aftermost position in order to obtain a maximum delivery of oil and therefore maximum speed of rudder travel under the condition of hand steering.
Again, assume that it is desired to move the rudder from amidships to the hard over left position. The steering wheel is turned left. Oil is delivered by the steering stand pump directly to the forward starboard ram and after port ram.
The rudder moves to the left. Oil from
a. The main Steering pump aft is stopped.
b. The change valve in the control room is set for hand operation.
c. The steering stand pump stroke lever
Figure 13-8. Starting control.
the after starboard ram and the forward port ram returns to the suction side of the steering stand pump. The rudder moves so long as oil is delivered to the rams
Figure 13-10. Stroke adjuster.
152
Figure 13-11. Shifting steering control.
delivered to the forward port and after starboard rams while at the same time, oil is returned from the after port and
forward starboard rams through the control valve to the return side of the main cutout manifold. Movement of the control valve handwheel for left rudder causes the oil to be delivered to the after port and forward starboard rams while, at the same time, oil is returned from the forward port and after starboard rams through the control valve to the return side of the main cutout manifold.
When steering by emergency power, the change valve should be set in the
emergency
Figure 13-12. Steering wheel.
by turning the steering wheel and thus driving the steering stand pump.
13C3. Emergency steering. Provision is made for steering by direct delivery of oil to the main rams from the main hydraulic system. Oil is delivered from the main cutout manifold to the steering stand. The emergency steering control valve on the steering stand is a piston type control valve. Oil returns from this valve to the return and low-pressure side of the main cutout manifold.
Movement of the control valve handwheel for right rudder causes the oil under pressure from the main cutout manifold to be
Figure 13-13. Starting control.
Figure 13-14. Change valve.
153
Figure 13-15. Main cutout manifold.
position. The emergency cutout valves in the hand and emergency cutout manifold should be opened and the hand cutout valves should be shut.
When the desired position of the rudder is reached, the handwheel must be
Figure 13-17. Emergency steering wheel.
conning tower, the handwheel control (in control room) must be disengaged. A clutch is provided for this purpose and must be engaged except when the link is connected for emergency steering from the conning tower. To steer by
emergency from the control room, this
brought back to neutral to stop rudder movement and to hold the rudder in the desired position. Arrangement is provided to connect the emergency control valve lever to the vertical steering shafting by a removable link, thereby making it possible to steer by the emergency system from the conning tower.
When emergency steering from the
Figure 13-16. Emergency steering pin.
removable link is not connected and the emergency steering control valve is moved by the handwheel. A locking pin is provided to hold the control valve in the neutral position when emergency steering is not being used. (See Figures 13-13 to 13-20.)
The electrical rudder angle indicating system is of the selsyn type. The rudder
Figure 13-18. Emergency control valve lock.
154
Figure 13-19. Shifting steering control.
angle transmitter is located in the after torpedo room on the port side and is driven through a rack and pinion from the port steering ram connecting rod.
There is one rudder angle indicator in each of the following locations: the bridge, the conning tower
Figure 13-20. Emergency connecting link.
steering station, the control zoom steering station, the control room diving station.
A mechanical rudder angle indicator, driven also from the port steering ram
connecting rod, is located in the after torpedo room.
155