RADIATOR HYDRAULIC TANK AND COOLER LINES ARRANGEMENT 3S1728 - Caterpillar

Illustration 1 g02757958
926 and 930 Models
(1) Front axle
(2) Parking brake
(3) Accelerator pedal
(4) Left pedal
(5) Brake, fan, charge pump
(6) Lube pump
(7) Hydrostatic drive motor 1
(8) Transmission oil filter
(9) Front transmission output yoke
(10) Joystick with forward, neutral, and reverse switch
(11) Hydraulic oil filter
(12) Electronic control module
(13) Hydraulic tank
(14) Engine
(15) Hydraulic oil cooler
(16) Rear axle
(17) Hydrostatic drive pump
(18) Hydrostatic drive motor 2
(19) Rear transmission output yoke
(20) Transmission
Illustration 2 g02824100
938 Model
(1) Front axle
(2) Parking brake
(3) Accelerator pedal
(4) Left pedal
(5) Brake, fan, charge pump
(6) Lube pump
(7) Hydrostatic drive motor 1
(8) Transmission oil filter
(9) Front transmission output yoke
(10) Joystick with forward, neutral, and reverse switch
(11) Hydraulic oil filter
(12) Electronic control module
(13) Hydraulic tank
(14) Engine
(15) Hydraulic oil cooler
(16) Rear axle
(17) Hydrostatic drive pump
(18) Hydrostatic drive motor 2
(19) Rear transmission output yoke
(20) Transmission
(21) Transmission oil cooler The hydrostatic system consists of many components, the first component is a variable displacement piston pump (17). The variable displacement piston pump (17) is splined into the coupling bolted to the engine flywheel. The hydrostatic pump (17) supplies hydraulic oil flow to the variable displacement bent axis piston motors (7) and (18).The variable displacement bent axis piston motors (7) and (18) are mounted to transmission (20). The piston motors (7) and (18) receive hydraulic oil flow from the variable displacement piston pump (17). The piston motors convert hydraulic energy to mechanical energy that is transferred to the inputs of transmission (20). Transmission (20) transmitts the energy provided by the piston motors to front axle (1) and rear axle (16). The front and rear drive shafts (not shown) transmit the energy from the output yokes (9) and (19), on transmission (20), to the axles. The parking brake (2) is mounted to the front axle. The parking brake is electronically controlled by a rocker switch on the right-hand console in the cab. A hydraulic solenoid actuates parking brake (2) on or off in response to the parking brake switch position. The service brakes are located in the front axle and the rear axle. The service brake is actuated by operator input greater than 50% on the left pedal (4).Brake/fan/charge pump (5) provides oil to the hydraulic braking system, hydraulic fan system, and hydrostatic drive charge. The charge oil is filtered by the hydraulic oil filter (11). Oil cooler (15) cools oil leaving the hydrostatic drive system from the case drain line of hydrostatic drive motor (18). Oil leaving oil cooler (15) is returned to the hydraulic tank (13).Lube pump (6) is mounted to the rear of brake/fan/charge pump (5). Oil from the lube pump is filtered by transmission oil filter (8). Lube oil routes from transmission oil filter (8) to the transmission. Lube oil on 938 machines is cooled by the transmission oil cooler (21). The lube oil lubricates the transmission and provides control oil pressure for the clutch inside the transmission. The clutch is operated by an electronic solenoid valve controlled by the ECM. The clutch is disengaged when a certain roading speed is reached.