Power transmission apparatus for a vehicle
AssigneeKoyo Seiko Co., Ltd.
InventorsShuzo Hirakushi, Yoshiaki Hamasaki, Goki Shimamura
Life of this patent
Estimating the term…
Abstract
A power transmission apparatus for a vehicle which is used for a four-wheel drive vehicle driving both the front and rear wheels by a driving force from an engine, in which a discharge amount of a hydraulic pump provided between a front wheel drive shaft and a rear wheel drive shaft to generate hydraulic pressure by a rotation speed difference between the two rotary shafts is desirably adjusted by a remote-controllable variable throttle valve provided on the way of a discharge oil passage extending from the hydraulic pump, so that a simple hydraulic circuit is used to make the coupling of two rotary shafts freely adjustable from loose condition to tight condition.
Claims14
A power transmission apparatus for a vehicle comprising:
- a hydraulic pump which connects to rotary shafts transmitting a driving force so as to generate hydraulic pressure corresponding a rotational speed difference between said rotary shafts,
- said hydraulic pump including suction and discharge ports, and hydraulic fluid circulating passage connecting said suction and discharge ports,
- stationary throttle means disposed in said circulating passage for providing a variable set of transmitted torque values between said rotary shafts in relation to the difference in rotative speed of such shafts, and
- variable throttle means operable independently of said hydraulic fluid disposed in said circulating passage for modifying said set of transmitted torque values.
A four-wheel drive vehicle comprising:
- a vehicle speed detector;
- a steering angle detector for detecting a steering angle of a front wheel;
- two hydraulic pump means connected between a rear wheel drive shaft and a left rear wheel and between said rear wheel drive shaft and a right rear wheel respectively for generating from hydraulic fluid a hydraulic pressure corresponding to a rotation speed difference between each said rear wheel and its said rear wheel drive shaft;
- variable throttle means operable independently of said hydraulic fluid disposed in a fluid discharge passage extending from each of said hydraulic pumps and having a variable opening ratio;
- stationary throttle means disposed in said fluid discharge passage;
- and
- opening ratio control means for respectively changing the opening ratio of said variable throttle means corresponding to the detected result of said steering angle detector or said vehicle speed detector or a combination thereof.
Dependencies are inferred from the claim text.