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:
May. 10, 1988
Filed:
Jun. 03, 1986
Setsuo Tokoro, Susono, JP;
Tomoyuki Watanabe, Susono, JP;
Takashi Hayashi, Susono, JP;
Takashi Shigematsu, Mishima, JP;
Abstract
A speed ratio control system for a continuously variable transmission is provided, wherein an oil flowrate to a hydraulic servo of an input or an output V-shaped pulley device is varied by a flow control valve, so that a speed ratio between the input and the output sides can be continuously changed. The system determines a deviation between a target value and a measured value and corrects the measured value in accordance with at least the characteristics of the flow control valve, so that the deviation and a rate of change per unit time of the speed ratio, or the deviation and a rate of change per unit time of a rotational speed of the input or output pulleys, will have a linear relationship over the entire area of control. This system avoids poor feedback gain because of the non-linearity of the characteristics of the flow control valve. Thus, the feedback gain is acceptable over the entire area of control of the continuously variable transmission. Even when the conditions of use are different, the speed ratio (or the input or output rotational speeds) can be stably controlled without disturbing the response.