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:
Mar. 07, 1989
Filed:
Dec. 14, 1987
Emerson L Kumm, Tempe, AZ (US);
Kumm Industries, Inc., Phoenix, AZ (US);
Abstract
A continuously variable transmission 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 control system. 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. Each pulley assembly includes a power consuming or producing element, such as an oil pump/motor, which is coupled through harmonic drive differential gearing to the guideway disks. When the load on the hydraulic unit operated as a 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. 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. An alternate configuration and control is disclosed for use when large pulley actuator torques are present due to the centrifugal forces acting upon heavier, stronger belt engaging elements selected for heavier duty applications.