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| Illustration 1 | g00635309 |
Components of the Propel Motor (1) Flushing valve (2) Port plate (3) Locating pin (4) Housing (5) Gear (6) Front cover (7) Retaining ring (8) Output shaft (9) Control plate (10) Rotary kit (11) Central pin (12) Piston (13) Retainer plate (14) Speed sensor | |
The left propel motor operates in the same exact manner as the right propel motor. Each propel motor is a fixed displacement bent axis motor. The drive motor can operate in either direction.
The following three hydraulic lines are connected to the motor: two high pressure loop lines and one case drain line.
Oil is supplied to the left propel motor by the left propel pump and to the right propel motor by the right propel pump. The direction of the motor rotation is controlled by the oil flow direction from the propel pump.
The following components of the motor rotate: output shaft (8), retainer plate (13), pistons (12) and rotary kit (10). The following components of the motor do not rotate: housing (4), port plate (2) and control plate (9). A spring on central pin (11) pushes barrel (10) against control plate (9). This makes a high pressure seal between the barrel and the control plate and this makes a high pressure seal between the control plate and port plate (2) .
When the high pressure oil from one of the ports enters the control slot that is located in control plate (9), the oil that is in the control slot goes into the cylinders of rotary kit (10) that are aligned with the control slots.
The spherical piston heads are held in the sockets in the drive shaft by retainer plate (13). Seven pistons (12 ) are held by rotary kit (10). The rotary kit rotates around central pin (11) which is at an angle to the axis of input shaft (8). When the pressure oil flows in and out of the cylinders, the seven pistons (12) move in and out of the cylinders. This is due to the arrangement of the barrel to the shaft of the bent axis type motor. This forces the following components to rotate: pistons, barrel and shaft. The speed of the motor is sent by speed sensor (14) to the propel electronic control module.
When the components continue to rotate, the pistons reach the fully retracted position. At the same time, the cylinder begins to overlap the control slot in control plate (9) on the low pressure side of the loop. At this point, the piston starts to move down. This pushes oil out of the cylinder through the control plate (9) and through the return side port of the loop. The motor is lubricated by oil leakage from the pistons and barrel.
Flushing Valve
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| Illustration 2 | g00635311 |
Components of the Flushing Valve (15) Spring (16) Charge relief valve poppet (17) Shim (18) Spring (19) Spool (20) Spring (21) Port A (22) Port B | |
The motor charge relief valve is set lower than the pump charge relief valve. Shim (17) between charge relief valve spring (18) and charge relief valve poppet (16) allows the charge relief valve to be adjusted. The maximum amount of oil flow is controlled by an orifice that is located next to charge relief valve poppet (16). During forward operation and reverse operation, the charge pressure is controlled by the relief valve that is located in the flushing valve.
Spool (19) has a pilot passage that is drilled from the left end to an intersecting hole. The intersecting hole is drilled between the two lands on the left side of the valve spool. The right side of the spool has a pilot passage that is drilled from the right end to an intersecting hole. The intersecting hole is drilled between the two lands on the right side of the valve spool.
When high pressure oil enters the valve assembly through port A (21), the oil flows through the pilot passage that is on the left side of spool (19) into the cavity of spring (15). The high pressure oil acts upon the left end of the valve spool in order to overcome the force of spring (20). This shifts the spool to the right. When the spool shifts to the right, the spool opens the passage to the charge relief valve (16). Oil from the low pressure side of the propel circuit flows from port B (22) to the charge relief valve.
When high pressure oil enters the valve assembly through port B (22), the oil flows through the pilot passage that is on the right side of spool (19) into the cavity of spring (20). The high pressure oil acts upon the right end of the valve spool in order to overcome the force of spring (15). This shifts the spool to the left. When the spool shifts to the left, the spool opens the passage to charge relief valve (16). Oil from the low pressure side of the propel circuit flows from port A (21) to the charge relief valve.
This provides a means of removing hot oil from the low pressure circuit. Because charge relief valve (16) in the shuttle assembly is set at a lower pressure than the charge relief valve in the propel pump, cooling oil from the charge pump can be added to the low pressure side of the circuit.
When the machine is placed in neutral, springs (15) and (20) center the shuttle valve in the passage. When the spool is in the center position, the passage is blocked to port A (21) and port B (22). No oil can flow to charge relief valve (16) .