Loading machine equipped with a first and a second pump supplying pressure oil to at least one hydraulically driven working component, such as a hydraulic piston-cylinder device or hydraulic motor
US5165862A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 17, 1991 |
| Grant date | Nov 24, 1992 |
| Priority date | — |
| Expiry date | Dec 17, 2011 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04B49/002
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A loading machine equipped with a first and a second pump for supplying hydraulic oil to at least one hydraulic operated working component, such as a hydraulic piston-cylinder device or a hydraulic motor having a varying oil-pressure and flow requirement, wherein the pumps can be connected together for mutual coaction, when necessary. The second, larger pump is a fixed displacement pump. The first pump is provided with a pump regulator which is influenced by the load pressure prevailing in the hydraulic system and is intended to influence the first pump in a manner to maintain between the outlet of the pump and the load pressure on the pump regulator a pressure difference determined by the pump regulator, wherein the first pump is connected to the working component via a variable restriction. A control device is operative to connect the second and larger pump to the system solely when there is a need for a smooth increase in flow which cannot be achieved solely by the first pump.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.