The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 29, 2004
Filed:
Aug. 26, 2002
Markku Jonninen, Lahti, FI;
Ideachip Oy, Hollola, FI;
Abstract
The invention relates to a leakage oil return apparatus for a hydraulic motor. The apparatus is used for returning the oil leaked from the working pressure space of a motor ( ) into a motor casing ( ) from the casing ( ) back to a return line ( ) of the motor. Consequently, the return pump ( ) driven by a shaft ( ) of the hydraulic motor ( ) has its suction side ( ) connected with said casing ( ) and its delivery side ( ) conencted by way of non-return valves ( ) with pressure and return lines ( ) of the motor ( ) in such a way that flow communication is established always with the line having a lower pressure. It is preferred that the return pump ( ) have its delivery side ( ) connected by way of a pressure proportional valve ( ) with said casing ( ). The pressure proportional valve ( ) is adapted to receive its control from the pressure ratio between a casing pressure and a pressure in the delivery side ( ) of the return pump ( ) in such a way that, as the casing pressure goes down below a given pressure limit or approaches the pressure of 0 bar, the pressure proportional valve ( ) switches the return pump's ( ) volume flow to free circulation i.e. back to the casing ( ).