Patent · US Expired

Gear control system intended in particular for an electrically operated automatic transmission of layshaft design

US6029531A · kind A · utility

3Cited by
7References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 22, 1998
Grant dateFeb 29, 2000
Priority date
Expiry dateMay 22, 2018

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T74/19251
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A gear control system intended in particular for an electrically operated automatic transmission of layshaft design comprises the following elements: a hydraulic system with pressure lines; a pump (5) for generating a system pressure; a first pressure reduction valve (6) for adjusting the system pressure; and switching elements (1, 2, 3, 4) at least one of which takes the form of a higher gear (1) for forward drive, another takes the form of a lower gear (2) for forward drive, another takes the form of a switching element for reverse drive (3) and another takes the form of a clutch (4). The switching elements can be actuated by pressure via the pressure lines with pilot valves (10, 11, 12) and switching of one of the switching elements (1, 2, 3) or clutch (4) is defined by the switching position of the pilot valves (10, 11, 12) and of a multi-directional valve (16) connected upstream of the switching elements (1, 2, 3). The gear control system has a reserve switching device which in the event of a voltage drop applies pressure to the multi-directional valve (16) to switch one of the switching elements (1, 2, 3) for forward or reverse drive as well as a switch-back safety device whi…

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