Four-wheel drive system
AssigneeToyoda Koki Kabushiki Kaisha
InventorHiroaki Asano
Life of this patent
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Abstract
A vehicular four-wheel drive system which includes: an oil pump adapted to be actuated by the relative rotations of a first rotating shaft connected to front wheels and a second rotating shaft connected to rear wheels for discharging pressure oil; a hydraulic clutch having a cylinder chamber communicating with the discharge passage of the oil pump; an electromagnetic throttle valve for controlling the discharge pressure of the oil pump; and a control mechanism for changing the throttle opening of the electromagnetic valve in accordance with the running situation of the vehicle.
Claims6
A four-wheel drive system having a torque transmission device between front wheels and rear wheels of a vehicle, said torque transmission device comprising:
- a stationary casing secured to a frame of said vehicle;
- an oil pump positioned in said casing and mechanically connected to be actuated by the relative rotations of a first rotating shaft connected to the front wheels and a second rotating shaft connected to the rear wheels for discharging pressure oil;
- a hydraulic clutch mounted in said casing, interposed between said first and second rotating shafts and having a cylinder chamber communicating with a discharge passage of said oil pump for selectively transmitting rotational power from one of said first and second rotating shafts to the other rotating shaft, the transmitted rotational power depending on the pressure of oil admitted in said cylinder chamber;
- an electromagnetic throttle valve fluidically connected to said discharge passage and having a solenoid for varying a throttle opening thereof in response to an electric current applied to said solenoid so as to control the pressure of oil admitted in said cylinder chamber;
- a speed sensor for detecting a traveling speed of said vehicle;
- a steering angle sensor for detecting a rotational angle of a steering wheel of said vehicle;
- and
- control means electrically connected to said speed sensor, said steering angle sensor and said solenoid of said electromagnetic throttle valve for applying to said solenoid an electric current depending on signals from said speed sensor and said steering angle sensor so as to vary the throttle opening of said electromagnetic throttle valve wherein said oil pump and said hydraulic clutch are mounted on facing end portions of said first and second rotating shafts, respectively, in tandem fashion.
Dependencies are inferred from the claim text.