Hydrostatic-mechanical gear for driving a mixing drum
AssigneeZF Friedrichshafen AG
InventorsWolfgang Gebhard, Egon Mann
Life of this patent
Estimating the term…
Abstract
The invention concerns a hydrostatic-mechanical gear for driving a mixed drum and, in particular, the drum of a concrete mixer vehicle. Cooling is provided for by the continuous removal of oil from a high pressure circuit, via a connecting pipe, and the constant feeding of the cooled oil, which has passed through an oil cooler, to the interior of a gear housing via a pipe. This pipe discharges into the interior of the gear housing immediately proximate a hydraulic motor. The oil then flows through the hydraulic motor, which is preferably a slow-speed radial piston motor, to reduce the noise generation of the hydraulic motor.
Claims14
A hydrostatic-mechanical gear, for driving a mixing drum of a concrete mixer vehicle, comprising:
- a hydraulic pump (2) being connected via supply and return pipes (4, 5) with a hydraulic motor (6) and forming therewith a high pressure circuit, and said hydraulic motor (6) driving said mixing drum via a planetary gear set (7);
- a pump housing (8) accommodating said hydraulic pump (2);
- a gear housing (9), having an interior, accommodating both said hydraulic motor (6) and said planetary gear set (7);
- a flushing slide valve (10) being attached to said supply and return pipes (4, 5) by connecting pipes (20, 21) so that, during operation of said hydrostatic-mechanical gear, heated oil is constantly removed from said high pressure circuit, via a flushing valve (11) and is replaced with cooled oil, and said flushing valve (11) being operatively connected with said flushing slide valve (10);
- wherein said heated oil passes through an oil cooler (12) and is continuously deposited, during operation of said hydrostatic-mechanical gear, within the interior of said gear housing (9) via a deposit pipe (19).
Dependencies are inferred from the claim text.