RING-NOZZLE 4634028 - Caterpillar

Illustration 1 g01758053
Hydraulic schematic for travel motor circuit (right travel motor)
(1) Motor
(2) Port for travel solenoid
(3) Displacement piston
(4) Crossover and line relief valves
(5) Counterbalance valve
(6) Load check valves
(7) Makeup valves
(8) Resolver
(9) Brake release valve
(10) Pressure reducing valve (brake)
(11) Port (pump and/or return oil from the travel control valve)
(12) Brake actuator
(13) Displacement control valve
(14) Port to case drain filter
(15) Travel motor circuit Motor
Illustration 2 g00926582
Rotary group
(3) Pump control piston
(16) Drive shaft
(17) Bearings
(18) Housing
(19) Pin
(20) Pistons
(21) Retainer
(22) Adjustment screw (output flow)
(23) Barrel
(24) Spring
(25) Port plate The travel motors are bent axis type motors.The flow of the oil from the main pumps depends on the direction of travel. The oil from the main pumps flows into the travel motor through port (11). Pump oil is forced out of the travel motor through port (11).The case drain oil returns to the hydraulic tank through a drain port (14) on the head of the travel motor.The oil from the main pumps flows into the right travel motor through port (11) during forward travel. The oil from port (11) flows through an internal passage in the motor head. The oil then flows through a passage in port plate (25) into barrel (23). The oil forces pistons (20) to move to the left.When piston (20) moves, barrel (23) rotates. Oil is discharged through a passage in port plate (25) by pistons (20) as barrel (23) rotates. The oil flows through an internal passage in the motor head. The oil then flows through port (11). Pistons (20) are connected to output shaft (16) by retainer (21). Output shaft (16) rotates sending power to the final drives.Displacement Control Valve
Small Displacement Change Operation
When the travel speed control switch on the control panel is set at the HIGH SPEED position the travel speed solenoid valve that is located on the pilot manifold is de-energized. The pilot system oil is blocked.The spool in displacement control valve (13) is shifted by the force of the spring in displacement control valve (13). Oil from the main pumps moves the piston in the displacement control valve (3). The angle of barrel (23) decreases. As a result, the motor displacement is decreased and travel speed is increased.Large Displacement Change Operation
When the angle of barrel (23) in the travel motor increases, the displacement of the travel motor increases. The angle of barrel (23) in the travel motor will increase and the travel speed will decrease when the travel speed control switch is moved to the LOW SPEED position.When the travel speed control switch on the control panel is moved to the LOW SPEED position, the travel speed solenoid is energized. The pilot system oil flows through a port to displacement control valve (13). The pilot oil forces the spool in displacement control valve (13) to shift. Oil from the main pumps moves the displacement piston (3). The angle of barrel (23) increases. As a result, the motor displacement is increased and travel speed is decreased.Operation
The travel motors can operate in FORWARD or REVERSE travel. The left and