Patent · US Expired

Variable speed accessory drive

US4526257A · kind A · utility

44Cited by
12References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 15, 1983
Grant dateJul 2, 1985
Priority date
Expiry dateDec 15, 2003

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16D27/112
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A drive mechanism (26) momentarily reduces the speed of engine-driven accessories in response to vehicle acceleration or increased power demands to improve fuel economy and to provide additional horsepower for the vehicle. The drive mechanism includes an electromagnetic clutch (48) operative, when engaged, to drive the accessories at constant speeds relative to speeds of an engine (10) and a viscous coupling (60) operative, when first engaged, in response to disengagement of the clutch, to first drive the accessories at a minimum speed and then to increase the accessory speeds to minimize shift shocks when the clutch is reengaged. The coupling includes a housing (58) defining an annular compartment (108) containing an annular clutch member (92) and a viscous liquid. A working chamber (113) within the compartment, defined by confronting surfaces of the housing and clutch member, transmits torque from the housing to the clutch member via viscous shear in response to relative rotation therebetween. An annular reservoir (114) circumscribing the working chamber receives liquid from the working chamber and minimizes the amount of liquid in the chamber when clutch (48 ) is engaged. A pump…

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