Patent · US Expired

Control system for hydraulic tandem pump in motor vehicle

US4798050A · kind A · utility

40Cited by
5References
3Claims
0Family size

Assignees

Inventors

Key dates

Filing dateJun 11, 1987
Grant dateJan 17, 1989
Priority date
Expiry dateJun 11, 2007

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB62D5/32
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

A control system for a hydraulic tandem pump assembly including a primary pump for supplying fluid under pressure to a power-assisted steering device and a secondary pump for supplying fluid under pressure to a hydraulic motor of an engine cooling fan, which pumps are mounted on a common drive shaft for rotation therewith. The control system includes an electrically operated flow quantity control valve disposed within a communication passage between the secondary pump and the hydraulic motor to bypass fluid under pressure discharged from the secondary pump into an inlet passage connecting a fluid reservoir to the secondary pump, a temperature sensor arranged to detect an ambient temperature of a prime engine of the vehicle for producing therefrom an output signal indicative of the ambient temperature, and an electric control apparatus connected to the sensor to control an electric current applied to the control valve in response to the output signal from the sensor in such a manner that the control valve is conditioned to bypass a large part or the entirety of fluid under pressure discharged from the secondary pump into the inlet passage when the ambient temperature of the engine i…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.