Hydraulic four-wheel-drive device

Abstract

Abstract PURPOSE:To make it possible to change the speeds of front and rear wheels with a simple cheap arrangement by disposing an auxiliary speed change unit between a fixed displacement type rear wheel drive motor and a rear differential gear unit so as to change the speed of the front wheels by means of a change-over device in association with the auxiliary speed change device. CONSTITUTION:Pressure oil discharged from a variable displacement pump P driven by an engine E is bifurcated and fed into a variable displacement type front wheel drive motor MF and a fixed displacement type rear wheel drive motor MR through constant ratio flow dividing valves 5, 6, respectively. In this arrangement, the variable displacement type front wheel drive motor MF is arranged so as to make the rotational speed of a motor shaft 7 variable in association with the rotational speed of a swash plate 2 which is associated with a steering wheel 1. In the above-mentioned arrangement, an auxiliary speed change mechanism N is disposed between the fixed displacement type rear wheel drive motor MR and a rear differential gear unit 20. Further, a change-over device A is disposed between the steering wheel 1 and the swash plate 2. Further, when the speed range of the auxiliary speed change mechanism N is changed into a road running speed range, the speed of the front wheels 11L, 11R is changed into the road running range.

Inventors

• 👤 Kojiro Yamaoka
• 👤 Tomoaki Azuma
• 👤 Kazuhiko Yano
• 👤 Ryota Ohashi

Bibliographic Details