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:
Sep. 06, 1988
Filed:
May. 19, 1987
Emerson L Kumm, Tempe, AZ (US);
Kumm Industries, Inc., Phoenix, AZ (US);
Abstract
A continuously variable transmission of the type employing a flat belt extending between driving and driven pulley assemblies, each having a circumferential array of radially adjustable belt engaging elements, is disclosed in conjunction with a self-energized control system for establishing the instantaneous radial position of the belt engaging elements. The radial positions of the belt engaging elements of each pulley assembly depend upon the angular relationship between inner and outer guideway disk structures carrying logarithmic spiral guideways oriented in the opposite sense, the resulting intersections of the spiral guideways supporting bearing regions at the ends of the belt engaging elements. Each pulley assembly includes a power consuming element, such as an oil pump, which is coupled through differential gearing, such as a harmonic drive, to the inner and outer guideway disks and to the power consuming element. When the load on the oil pump is changed by changing the output pressure against which it pumps, the angular relationship between the inner and outer guideway disk structures changes to correspondingly change the positions of the guideway intersections and hence the radial positions of the belt engaging elements. Since the belt is of fixed length, the other pulley assembly must change its effective diameter in the opposite direction, and this response is facilitated by changing the output pressure of its oil pump in the opposite direction. Very fast ratio changes may be expedited by supplying oil to the appropriate one of the oil pumps in sufficient quantity to permit it to transiently motor.