System for controlling a hydraulic vehicle drive
US6338247B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 19, 1999 |
| Grant date | Jan 15, 2002 |
| Priority date | — |
| Expiry date | Nov 19, 2019 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H61/4017
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic vehicle drive, having a closed hydraulic circuit consists of a variable displacement pump and one or several hydraulic motors. The variable displacement pump is driven by a diesel engine. During the braking or pushing operation of the vehicle, the hydraulic motor becomes a pump and drives the variable displacement pump which, in turn, acts as a motor upon the diesel engine and acts to accelerate the latter. Thus, the intended braking effect prevents the danger that the diesel engine will reach non-permissible high revolutions per unit time, which is particularly dangerous for diesel engines with turbochargers. In order to prevent non-permissible high revolutions per unit time, a pressure regulator acting as a throttle is placed in the return line between the hydraulic motor and the variable displacement pump. The valve throttles the rate of flow when the pressure of the hydraulic fluid in the line exceeds a certain desired value during the braking operation. In this way, a pressure at the variable displacement pump that is too high is prevented and the diesel engine does not enter the realm of dangerous revolutions per unit time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.