Fuji Tekko Co., Ltd.

Hideaki Ina

Satoru Suzuki

Takehisa Yamada

Two rotary shafts to transfer a motive power are relatively rotatably coupled. One of the shafts is coupled to a rotor and the other is coupled to a cam. A plurality of plungers which execute a stroke motion in the axial direction by the relative rotation with the cam are provided for the rotor. The oil injection and discharge into/from the plunger enclosing chamber are executed by a rotary valve. The rotary valve automatically switches a phase relation so as to obtain correct opening/closing timings even if the direction of the relative rotation changed. The rotary valve rotates integratedly with the cam side and opens or closes intake/discharge holes of the plungers for a plurality of intake ports and discharge ports which are alternately formed on the cam surface. The discharge ports on the front surface of the rotary valve are mutually coupled by communicating grooves formed on the back surface. An orifice is formed between the communicating groove and the intake port. A force by hydraulic reaction forces of the front and back surfaces of the rotary valve is set to be smaller than a force by a plunger liquid pressure acting area which is applied to the rotary valve. Thus, a force such as to always closely adhere a gap between the rotor and the rotary valve is generated, thereby minimizing an oil leakage from the rotary valve.

Rotary shaft coupler with rotary valve plate position dependent on

Two rotary shafts for transmitting power are coupled so as to be relatively rotatable. When a rotational speed difference occurs between the two shafts, a torque corresponding to the rotational speed difference is hydraulically generated and is transmitted from the shaft of the higher rotational speed to the shaft of the lower rotational speed. A cam surface having two or more cam mountains is formed on the inside edge surface of the cam housing. A rotor is assembled in the cam housing so as to be relatively rotatable. The rotor faces the cam surface and is formed with a plurality of plunger chambers in the axial direction. Plungers are movably assembled in the plunger chamber through return springs. The plunger chambers are connected to the high pressure chamber through delivery passages having delivery valves. The plunger chambers are communicated with the low pressure chamber through suction passages having suction valves and oil circulating grooves formed in the axial direction of the rotor outer peripheral surface. A throttle mechanism operated by an increase in oil temperature and in pressure in the high pressure chamber is arranged between the high and low pressure chambers. A variable orifice mechanism whose orifice cross sectional area changes with an increase in delivery pressure may also be provided in place of the throttle mechanism.

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Kosai, Japan

Hideaki Ina