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| Illustration 1 | g00685701 |
Schematic of the Differential Control System (1) Speed control valve. (2) Differential lock control valve. (3) Front travel motors. (4) Rear travel motors. (5) Differential lock valve (front). (6) IQAN monitoring and control system. (7) Speed selector switch. (8) Differential lock switch. (9) Differential lock switch. (10) Differential lock valve (rear). (C) Charge pump oil. (D) Pump oil from the front power train pump. (E) Pump oil from the rear power train pump. (F) Pump oil from the front power train pump. (G) Pump oil from the rear power train pump. | |
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| Illustration 2 | g00570733 |
(6) IQAN monitoring and control system. (7) Speed selector switch. (8) Differential lock switch. (9) Differential lock switch. (11) Differential lock lamp. | |
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| Illustration 3 | g00570740 |
(1) Speed control valve. (2) Differential lock control valve. (12) Hydraulic oil tank. | |
The front power train pump supplies oil flow to the hydrostatic drive loop for the front travel motors. The rear power train pump supplies oil flow to the hydrostatic drive loop for the rear travel motors.
Front travel motors (3) share oil flow from the front power train pump. Rear travel motors (4) share oil flow from the rear power train pump. The oil flows between the two travel motors. The oil also seeks the travel motor that has the least load. This causes a differential effect.
Note: Unnecessary use of the differential lock causes heat to build up in the power train.
The differential lock valve divides power between the left travel motor and the right travel motor.
When differential switch (8) or (9) is activated, an electrical signal is sent to IQAN (6). IQAN (6) sends this electrical signal to the solenoid of differential control valve (2). The solenoid shifts the spools in differential control valve (2). This causes charge pump oil to flow to front differential lock valve (5) and rear differential lock valve (10) .
The charge pump oil shifts the spools upward in both differential lock valves. This causes oil from the power train pumps to flow through the differential lock valves. The oil then flows to the travel motors.
The differential lock valve sends more oil flow to the slowest travel motor.
The differential lock is operational when the machine is in first speed and in work mode. When the machine speed exceeds 60% of the maximum speed, the differential lock turns off automatically.
Note: The differential lock is only functional when the machine is in the work mode. The differential lock is not functional when the machine is in the road mode. When the differential lock is activated, "Diff" is displayed on the IQAN display screen.
The automatic shut off function of the differential lock valves can be overridden by pressing the differential lock switch (9). When differential lock switch (9) is activated, differential lock lamp (11) comes on.
Differential lock switch (9) allows the differential lock to remain on when the machine speed exceeds the preset limit.
Note: The differential lock effect is not 100%. This allows the steering to be used when the differential lock is switched on.
When the machine speed increases, the differential lock valve moves down. When the differential lock valve moves down, the differential lock is not active. This protects the system.