Illustration 1 | g06134586 |
Typical of a 914K (1) Front axle (2) Parking brake (3) Drive shaft (4) Accelerator pedal (5) Charge pump (6) Joystick with forward, neutral, and reverse switch (7) Hydraulic oil tank (8) Hydraulic oil filter (9) Rear axle (10) Hydrostatic piston pump (11) Transfer gear group (12) Hydrostatic piston motors |
The power train is a hydrostatic system. The engine drives piston pump (10) which then drives piston motor (12). The hydrostatic system is a closed loop. Oil is continuously pumped between piston pump (10) and piston motor (12).
The charge pump (5) charges the system at start-up and the charge pump provides makeup oil. Oil is directed by charge pump (5) through filter group (8). Filter group (8) filters the oil before entering piston pump (10) and piston motor (12). The charge pump (5) also provides the source for signal pressure to control pump (10). The signal pressure is controlled electronically to vary proportionally to the engine speed. This relationship is handled electronically. As the engine speed becomes higher, the signal pressure will become higher.
The piston motor (12) is mounted to a transfer gear group (11). The transfer gear group (11) allows one piston motor turn both the front wheels and the rear wheels. Power from transfer gear group (11) is transferred to front axle (1) through drive shaft (3). The rear axle (9) receives power directly from transfer gear group (11). The parking brake (2) is mounted on the drive shaft near the front differential. The service brakes are mounted in the axle and are oil immersed.
The direction of the machine is controlled by the direction control switch that is located in the cab on joystick (6). The speed of the machine is controlled by accelerator pedal (4). If the machine is equipped with a creeper control, the speed of the machine can also be controlled by the creeper control.
The machine will shift to NEUTRAL, if the parking brake lever is engaged and the direction control switch is in the FORWARD or REVERSE position. To get the machine to move, the direction control switch must be moved to NEUTRAL and the parking brake must be disengaged. Then, the direction control switch must be moved to the desired direction.
The speed control switch controls the speed range of the machine. The machine can be switched between speed range SR1, SR2, and SRH at any time. SR1 and SR2 are made available by selecting "LOW" on the speed switch.