HOUSING 1483663 - Caterpillar

Illustration 1 g03401066
D9T Hydraulic steering motor (left turn)
(1) Output shaft
(2) Speed sensor
(3) Retaining plate
(4) Port "T1" (case drain)
(5) Pistons
(6) Barrel
(7) Head
(8) Passage from pistons
(9) Passage to pivot pin
(10) Control plate
(11) Case
(12) Port "T2" (plugged case drain)
(13) Pivot pin
(14) Passage to steering pump
(15) Steering motor
(16) Flushing valve
(17) Passage from steering pump
(18) Flushing valve pin
(19) Passage to pistons
(20) Return to tank
(21) Ring gear
(BB) Cutaway section
(CC) Component surface
(FF) Activated components
(GG) Tank pressure
(KK) High pressure
(LL) First pressure reduction The steering motor is a fixed displacement bent axis motor with an internal flushing valve that is located in control plate (10). The motor is operated by oil flow from the variable displacement steering pump. Oil flow through the motor can be in either direction. A change in the direction of the motor does not change the amount of output torque from the shaft of the motor. The steering motor uses straight transfer gears to drive the planetary in the differential steer unit.Speed sensor (2) uses the ring gear (21) to determine the speed and rotation of the steering motor. Speed sensor (2) sends electrical signals to the power train ECM.The following components of the motor rotate:
Output shaft (1)
Retaining plate (3)
Pistons (5)
Barrel (6)
Pivot pin (13)
Ring gear (21)The following components of the motor do not rotate:
Head (7)
Control plate (10)
Case (11)
Control plate (10) including flushing valve (16)Oil from the steering pump flows to the steering motor. The oil flows to the inlet port in control plate (10). The direction of the flow from the steering pump will determine the inlet and outlet ports in control plate (10). Oil flows through the control plate to pistons (5) in barrel (6). The spherical heads of pistons (5) are held by retaining plate (3). Retaining plate (3) is part of output shaft (1). The other end of the pistons slip into the barrel (6). The barrel rotates around pivot pin (13). Because of the angle between the barrel and the output shaft, the pistons move in and out of the barrel as oil is forced through the control plate from the steering pump. As a result, the rotation of the pistons and the barrel cause the output shaft to rotate.As the output shaft (1), pistons (5), and barrel (6) rotate, the pistons (5) reach the top center position (fully extended position). At the same time, the barrel (6) begins to overlap passage (19) in the control plate. Oil fills the barrel (6). Now, the piston (5) starts to move back into the barrel (6). Because the pistons (5) move into the barrel (6), the pistons (5) push oil out of the barrel (6) through passage (8) through control plate (10) to passage (14) to the steering pump.The pressure oil in either passage (14) or (17) moves flushing valve pin (18). Low-pressure return oil flows into passage (9) through the slots in the flushing valve pin. A drilled passage in pivot pin (13) allows the oil to flow to the pivot pin socket and on through passages to the motor bearings.