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:
Jul. 22, 2008
Filed:
Feb. 02, 2006
Paul Von Baeumen, Sindelfingen, DE;
Dirk Hoevemeyer, Dettingen, DE;
Hans Renz, Filderstadt, DE;
Putzmeister Aktiengesellschaft, Aichtal, DE;
Abstract
The invention relates to a hydraulic drive, especially for two-cylinder thick matter pumps. Said hydraulic drive comprises at least one main pump () embodied as a hydraulic variable displacement pump, and two hydraulically actuatable drive cylinders () that are each connected to a connection line () of the main pump () by means of pump connections mounted on one end thereof, forming a closed hydraulic circuit, and communicate with each other at the ends thereof opposing the pump connections () by means of a swinging oil line (). The hydraulic drive also comprises a feed pump (), by which means pressurized oil is fed from an oil tank to the current low-pressure side into the hydraulic circuit, and a flushing branch (), by which means a flushing oil flow is branched off from the current low-pressure side under a limited pressure into the oil tank (). In order to avoid low-pressure influxes during the reversal process of the main pump (), the flushing oil flow is blocked and then released in a time-delayed manner during each reversal process of the main pump (), independently of the differential pressure in the connection lines.