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| Illustration 1 | g00281508 |
Piston Motor (On Demand Fan) | |
The piston motor (on demand fan) is located between the engine and the radiator. The piston motor (on demand fan) is mounted in a shroud that separates the engine from the fan. The piston motor (on demand fan) turns a fan that cools the hydraulic oil in the hydraulic oil cooler. The fan also cools the engine coolant in the radiator.
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| Illustration 2 | g00762363 |
Components for the Piston Motor (On Demand Fan) (1) Inlet line to fan motor. (2) Fan motor. (3) Outlet line from fan motor. (4) Case drain. (5) Check valve. (6) Adjustable relief valve. | |
Pressurized oil from the piston pump (on demand fan) flows to the motor through inlet line (1). The pressurized oil causes the pistons to move within the barrel of the motor. The pistons cause the barrel and the motor shaft to rotate. The oil exits piston motor (on demand fan) (2) through outlet line (3) .
Piston motor (on demand fan) (2) rotates at a variable speed. The speed of rotation is dependent on the flow of oil from the piston pump (on demand fan). If the oil pressure exceeds the pressure setting of relief valve (6), the relief valve opens. The oil that flows through the relief valve exits at outlet port (3) .
Relief valve (6) is located within the housing of the piston motor (on demand fan) (2). The relief valve will allow excess oil to flow to the hydraulic oil tank. The relief valve opens if the pressure of the oil in the piston motor (on demand fan) exceeds approximately 12500 kPa (1800 psi).
Check valve (5) allows the reverse flow of oil through piston motor (on demand fan) (2). If the pressure at outlet line (3) is higher than the pressure in inlet line (1), oil will flow through the check valve. This will prevent the motor from cavitating.
Reference: For additional information regarding the fan drive system, refer to the Service Manual module Systems Operation, "Fan Drive System (On Demand Fan)" for the machine that is being serviced.
Reference: For additional information about the piston motor, refer to the Service Manual module Specifications, "Piston Motor (On Demand Fan)" for the machine that is being serviced.
Reference: For additional information about the piston motor, refer to the Service Manual module Testing and Adjusting, "Fan Drive Speed - Test and Adjust" for the machine that is being serviced.