COUPLING AS- 3236212 - Caterpillar

Illustration 1 g06081362
Right Propulsion Motor
(1) Final drive
(2) Shift actuator
(3) Port"X1"
(4) Flushing relief valve
(5) Port"A"
(6) Port"L2"
(7) Speed sensor
(8) Port"B"Note: The above illustration shows the right propulsion motor. The left propulsion motor is identical except for orientation.Each propulsion motor is a piston-type motor with a variable displacement. The bidirectional motor has two speeds and is a bent axis design.Each motor drives a track through single-speed planetary final drive (1). The ports on the motors are marked for identification. On the left motor, port"A" (5) is the reverse port, and port"B" (8) is the forward port. On the right motor, port"A" is the forward port, and port"B" is the reverse port. Port"L2" (6) is the case drain port on the right motor.Note: Port"L1" is the case drain port on the left motor.Each propulsion motor is equipped with hydraulic shift actuator (2). The two-position actuator is a servo piston that controls the position of the valve segment in the motor. The valve segment position determines the displacement and speed of the motor.Oil from the high-pressure circuit is directed to either end of the servo piston to facilitate high-speed or low-speed operation. This oil flow and the position of the servo piston is controlled by a pilot-operated speed valve within shift actuator (2). Oil from the shift solenoid is directed to port"X1" (3) to operate the speed valve.When oil pressure is not applied to the speed valve, oil in the high-pressure circuit shifts the motor to maximum displacement. In this case, the motor operates in low speed. When oil pressure is applied to the speed valve, high-pressure circuit oil shifts the motor to minimum displacement. In this case, the motor operates in high speed.Each motor is equipped with dual-signal speed sensor (7). A multi-tooth ring on the output shaft of the motor rotates past the tip of the speed sensor. Each time a tooth passes the sensor, an electrical impulse is sent to the transmission ECM. These impulses are out of phase with one another. The transmission ECM converts the frequency of the impulses to a vehicle speed and the phase of the impulses into a travel direction.Each propulsion motor contains a flushing valve. Flushing valves direct oil from the low-pressure side of the propulsion loop to flushing relief valve (4). The flushing relief valves open when the pressure in the low-pressure side of the propulsion loop is greater than the flushing relief pressure setting. Each flushing relief valve directs a metered amount of oil from the low-pressure side of the loop into the motor case drain. The case drain line on each motor directs oil from the motor cases to the cooler bypass manifold.
Illustration 2 g06081375
Propulsion Motor Cross Section
(4) Flushing relief valve
(9) Flushing spool
(10) Servo piston
(11) Minimum displacement limiter
(12) Pistons
(13) Speed pickup ring
(14) Output shaft
(15) Barrel assembly
(16) Valve segmentThe propulsion motor has a bent axis. The motor shifts speed when the axis of the motor is changed. Servo piston (10) changes the axis angle through positioning of valve segment (16).When valve segment (16) moves