Patent · US Expired

Four wheel drive mechanism

US5687808A · kind A · utility

7Cited by
6References
34Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 17, 1995
Grant dateNov 18, 1997
Priority date
Expiry dateMar 17, 2015

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB60K17/356
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

A torque is transmitted between a fluid pressure pump driven together with drive of a vehicle, and a fluid pressure motor that rotates together with driven wheels. The fluid pressure motor has two ports, and rotates in accordance with the direction of fluid supply to the ports. Fluid is circulated from one port to the other according to the input of rotation torque from the driven wheels. A high pressure flowpath connected to the pump outlet, and a low pressure flowpath connected to the pump inlet, are connected to these ports, and the connection direction is reversed when the rotation direction of the drive wheels is reversed. The low pressure flowpath is therefore always at low pressure regardless of the rotation direction of the drive wheels, and by controlling the pump supply flowrate so as not to exceed a predetermined value, torque is not transmitted when the vehicle is running at high speed.

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