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:
Apr. 29, 1980
Filed:
Nov. 04, 1977
John R Olson, Oconomowoc, WI (US);
Dynex/Rivett Inc., Pewaukee, WI (US);
Abstract
A method and apparatus for hydraulically driving and controlling a cooling fan. The apparatus includes a variable displacement hydraulic pump driven by a prime mover and a hydraulic motor connected to the pump and being driven thereby. The motor in turn is connected to a fan which serves to cool fluid passing through an associated heat exchanger. A temperature/force transducer monitors the temperature of fluid flowing from the exchanger and serves to control a pilot relief valve associated therewith. A pressure regulator is connected to the pump and acts in cooperation with the relief valve to control fluid pressure from the pump and thus torque of the motor and speed of the cooling fan. The method includes the steps of pumping hydraulic working fluid to a motor and driving the motor with the full hydraulic output of the pump to power a fan associated with a cooling system heat exchanger. The method further includes the steps of sensing the temperature of fluid leaving the exchanger and controlling the pressure of fluid from the pump in response to the temperature of the fluid leaving the radiator and thereby hydraulically controlling the speed of the fan associated with the radiator.