Reservoir loading valve with pressure protection of the reservoir circuit

US4683909A · kind A · utility

Assignee

• Mannesmann Rexroth AG · DE

Inventor

• Kurt Wittich · Bad Hersfeld, DE

Key dates

• Filing date: Feb 5, 1985
• Grant date: Aug 4, 1987
• Expiry date: Feb 5, 2005

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T137/7794
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A reservoir loading valve accomplishing a pressure protection of the reservoir circuit comprises a pre-control valve subject to the pressure of the control circuit and which controls depending on this pressure a switching valve the piston of which in turn controls the connection between a pump and a working hydraulic and the reservoir circuit. The reservoir circuit is supplied with pressure fluid through a blind bore and a transverse bore in the piston of the switching valve, while a flow control orifice is provided in the blind bore and controls the size of the flow of volume flowing to the reservoir circuit. When the reservoir is loaded and the working hydraulic circuit is connected, the piston of the switching valve will be displaced by the high pressure delivered by the pump into a position in which the connection between the pump and the reservoir circuit is completely interrupted. In this way pressure peaks occurring in the working circuit and which may exceed the maximum permissible reservoir pressure cannot affect the reservoir circuit. Furthermore, it is also possible to operate the working hydraulic circuit with pressures far beyond the maximum permissible pressures if th…