Patent ID: 8333069
Filing Date: 2012-12-18
Classification: B60K,F16H

Abstract:
1. Hydrostatic transmission apparatus for a vehicle having at least two drive members disposed one after the other in a direction of travel of said vehicle, the apparatus comprising at least two hydraulic motors suitable for driving respective ones of said drive members, each hydraulic motor having two main orifices serving respectively as feed and as discharge in a preferred direction of travel of the vehicle, a main hydraulic pump connected to two main ducts that serve respectively as feed and as discharge in the preferred direction, and a bypass valve suitable for taking up a reduced-speed position in which the feed main orifices of the motors are connected to the feed main duct, while the discharge main orifices are connected to the discharge main duct, and an increased-speed position in which at least one motor is bypassed, the feed main orifice of said bypassed motor being connected to the discharge main duct via a bypass link, while the other main orifices continue to have their respective links, said apparatus further comprising constriction means suitable for being activated to restrict the flow of fluid through said bypass link, so as to put the two main orifices of said bypassed motor at different pressures.