The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 19, 1989
Filed:
Jul. 27, 1988
Takashi Iino, Saitama, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A hydraulic control device for a continuously variable vehicle transmission having a closed hydraulic circuit disposed between a hydraulic pump and a hydraulic motor, with at least one of said hydraulic pump and said hydraulic motor being of the variable displacement type. The hydraulic pump is driven by an engine and the hydraulic motor is connected to the road wheels and is driven by hydraulic pressure from the hydraulic pump. A pair or relief valves are disposed between the two oil passages of the closed hydraulic circuit extending between the hydraulic pump and the hydraulic motor, each of which are for relieving the pressure from one oil passage to the other oil passage. One relief valve relieves the pressure from the oil passage which has the higher pressure when the continuously variable transmission is driven by driving forces from the engine to drive the road wheels, and has a relief pressure setting controlled so as to increase as the speed of rotation of the engine increases. The other relief valve which relieves the pressure from the other oil passage which increases in pressure when said continuously variable transmission receives driving forces from the road wheels, has a relief pressure setting controlled so as to increase as the speed of the motor vehicle increases.