Speed and steering control of a hydraulically driven tractor

Patent metadata

Field	Value
Publication number	US-8985252-B2
Application number	US-201213681087-A
Country	US
Kind code	B2
Filing date	Nov 19, 2012
Priority date	Nov 19, 2012
Publication date	Mar 24, 2015
Grant date	Mar 24, 2015

Abstract

A tractor has hydraulically driven wheels at a cab end and castor wheels at an engine end. Each driven wheels is driven by a hydraulic motor with a continuous adjustment of the motor displacement, with the motor being driven by a pump also having continuous displacement. The motor displacement is controlled by an electronic controller in response to stroking of the speed control lever to manage the displacement to provide required drive torques at different points in the stroke. There is provided an automatic steering system having a guidance controller arranged to receive GPS position information which controls the steering by differentially adjusting the displacement of the motors so that the automatic steering is independent of the manual steering which controls the pumps.

First claim

The invention claimed is:

1. A hydraulically driven tractor comprising:
a tractor frame;
an engine mounted on the tractor frame;
a cab mounted on the tractor frame for a tractor driver;
a first and a second driven wheels of the tractor mounted at a driven end of the tractor, the first driven wheel including a first hydraulic drive motor for driving the first wheel and the second driven wheel including a second hydraulic drive motor for driving the second wheel;
two non-dri…

Assignees

• Macdon Ind Ltd

Inventors

• Otto Phil
• Macgregor Don
• Bergman Leonard

Classifications

• B62D11/04 Primary

  Operations & Transport · mapped topic

• B62D11/001 Primary

  Operations & Transport · mapped topic

• A01B69/007

  Human Necessities · mapped topic

• B62D1/22

  Operations & Transport · mapped topic