Control system for a hydrostatic transmission
US5875631A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 11, 1996 |
| Grant date | Mar 2, 1999 |
| Priority date | — |
| Expiry date | Dec 11, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB62D11/005
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A hydrostatic transmission has a pair of overcenter variable displacement pumps, each having a flow control element controlled by a double acting actuator to control direction and flow rate of the pump. Fluid pressure in first and second chambers of each actuator are equal at a neutral position of the transmission. A forward control valve controllably communicates the first chambers of both actuators to a tank through a first orifice to reduce the pressure in the first chambers to simultaneously move the flow control elements in a first direction for forward travel. A reverse control valve controllably communicates the second chambers of both actuators to the tank through a second orifice to reduce the pressure in the second chambers to simultaneously move the flow control elements in a second direction for reverse travel. A right turn is made by selectively reducing the pressure in the second chamber of the right actuator during forward travel and in the first chamber during reverse travel by establishing fluid flow to the tank from the first or second chamber through a right turn position diverter valve and a right turn control valve. A left turn is made by selectively reducing t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.