CYLINDER & SEAL GP-OFFSET 1799710 - Caterpillar

Illustration 1 g00533341
Steering Motor
(1) Barrel
(2) Pin (pivot)
(3) Pistons (seven)
(4) Retaining plate
(5) Shaft
(6) Case
(7) Port plate
(8) Head
(9) Spring
(10) Control slot
(11) Pin
(12) Passage to case
(13) Control slot The steering motor is a fixed displacement bent axis motor with a self-contained flushing valve. The valve is located in port plate (7). The motor is operated by pressure oil from the steering pump. A change in the direction of oil flow through the motor does not change the amount of output torque from the shaft of the motor.Oil flow through the motor can be in either direction. A change to the direction of oil flow changes the direction of rotation of barrel (1), pistons (3), and shaft (5).The components of the motor that turn are the following components: shaft (5), retaining plate (4), pistons (3) and barrel (1). The parts that do not turn are the following components: head (8), case (6) and port plate (7).Oil from the pump flows to the steering motor. Oil then flows through a port in head (8). The direction of the oil flow from the steering motor determines the port in head (8) that is the inlet or the outlet. The oil flows through the corresponding control slot of port plate (7). Oil through port plate (7) flows into the cylinders of barrel (1).The spherical heads of pistons (3) are held in sockets in shaft (5) by retaining plate (4). The seal end of pistons (3) are positioned in barrel (1). Barrel (1) rotates about pivot pin (2). Because of the arrangement between the pistons and the shaft, pistons (3) move in and out of the barrel. The pistons move as the pressure oil leaves the cylinders and the oil enters the cylinders. The pressure oil from the inlet control slot forces the pistons out of the barrel. This causes shaft (5) and barrel (1) to rotate.As shaft (5), pistons (3) and barrel (1) continue to rotate, the pistons reach the top center position. At the same time, the cylinder begins to overlap the outlet control slot in port plate (7). At this point, the piston starts to move back into the barrel. By moving into the barrel , the pistons push oil out of the cylinder into the outlet control slot in port plate (7). The oil flows through the outlet port in head (8) and back to the pump. The ball (head) of center pin (2) is the pivot point for barrel (1).The flushing valve is located in port plate (7). The valve allows a portion of the return oil to flow from the low pressure side to case (6). The oil is used to cool the components of the motor and the steering closed loop. Also, the oil lubricates the motor. The oil that is lost through the flushing valve is replaced with oil from the charge circuit.Pressure oil in control slot (10) or (13) moves pin (11) toward the low pressure slot. Slots in pin (11) allow low pressure return oil to flow