Fluid Pump: Description and Operation

OIL PUMP
Outline





The trochoid gear oil pump has a flow rate control mechanism for improving discharge efficiency, quietness, and weight reduction.

Construction
An outer rotor, inner rotor, and oil pump flange are installed within the pump housing of the trochoid gear oil pump. The oil pump flange and oil pump shaft are coupled to the inner rotor. The other end of the oil pump shaft is coupled to the pump impeller side of the torque converter, and via the converter, to the engine. As a result, the oil pump flange, the inner rotor, and the outer rotor rotate as one with the engine. A spool and spring installed in the discharge section of the pump housing regulates the oil discharge amount.

Operation





1. When the speed of the engine is low, the spool is as shown in Fig. B. The amount of oil discharged increases in proportion to engine rpm.
2. When the engine rpm increases and the p-p differential pressure becomes greater, the spool is pressed against the spring, and compresses it as it moves to the right. When the spool is in the position shown in Fig. A, the oil is redirected through port A to port B and circulates back to the inlet side of the pump. This results in a fixed amount of oil that can be discharged.