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:
Feb. 20, 1990
Filed:
Jul. 23, 1987
Takashi Iino, Saitama, JP;
Koji Yamaguchi, Saitama, JP;
Eiichiro Kawahara, Saitama, JP;
Kazuya Maki, Saitama, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A hydraulically operated continuously variable transmission includes a hydraulic pump coupled to an input shaft, a variable-displacement hydraulic motor coupled to an output shaft, and a closed hydraulic circuit interconnecting the hydraulic pump and the hydraulic motor and including a passage connecting the inlet and outlet ports of the hydraulic pump. A servomotor makes and breaks the hydraulic circuit respectively by opening and closing the outlet port. A clutch valve continuously varies the cross-sectional area of the passage to change the amount of power transmitted between the hydraulic pump and the hydraulic motor. A control system independently controls the servomotor and the clutch valve, the control system being arranged to hold the servomotor in a position to open the outlet port when the clutch valve is opened beyond a prescribed degree. The hydraulic motor has motor plungers axially movable through a stroke which is variable by a tiltable motor swash plate which can be tilted by another servomotor. The servomotors include pilot valves which are operatively coupled to each other by a cam mechanism. The hydraulic circuit is kept broken when a motor vehicle incorporating the transmission runs at a prescribed speed or a higher speed and the angle of inclination of the motor swash plate is substantially minimal.