Patent · US Expired

Powershift transmission for an agricultural tractor

US5117702A · kind A · utility

14Cited by
7References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 28, 1991
Grant dateJun 2, 1992
Priority date
Expiry dateMay 28, 2011

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T74/19405
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A sixteen forward speed, four reverse speed transmission is provided having a very high efficiency and excellent shift quality. The gear ratios are selected so that a relatively large ratio spacing is provided between each gear step in the low-speed PTO usage range and in the high-speed transport usage range, while a much smaller gear ratio spacing is provided in the intermediate tillage or field usage range. The gear ratios are selected to minimize the number of clutches being changed to shift from one gear to the next, with minimal speed and momentum differences required inside the transmission during each shift. Just two shifts have a large ratio change, and they are positioned in locations having minimal usage, thereby minimizing operator awareness of these gear ratio spacings. The total number of meshes through the transmission is minimized to provide maximum efficiency.

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