초록

A hydrostatic drive apparatus for transferring power from a light duty vehicle engine to an output axle, including a charge pump for providing additional hydraulic fluid to a hydrostatic transmission in the apparatus, wherein the charge pump is mounted external to the housing of the drive apparatus.

대표청구항 ▼

An apparatus for transmitting power from a vehicle engine to an output shaft, comprising: a housing; a hydrostatic transmission disposed substantially within said housing, said hydrostatic transmission comprising a center section having hydraulic porting formed therein; a pump mounted on said center

An apparatus for transmitting power from a vehicle engine to an output shaft, comprising: a housing; a hydrostatic transmission disposed substantially within said housing, said hydrostatic transmission comprising a center section having hydraulic porting formed therein; a pump mounted on said center section and drivingly linked to said vehicle engine; and a motor mounted on said center section and hydraulically connected through said hydraulic porting to said pump, said motor being drivingly connected to said output shaft; a sump containing hydraulic fluid in flow communication with said hydrostatic transmission for supplying hydraulic fluid thereto; a charge pump mounted on an external surface of said housing and spaced from said hydrostatic transmission for creating high pressure hydraulic fluid; a gallery, in hydraulic fluid flow communication with said charge pump and said hydraulic porting, formed in the space between said charge pump and said hydrostatic transmission for providing a storage location for a quantity of said high pressure hydraulic fluid; at least one check valve associated with said hydraulic porting for controlling the flow of said high pressure hydraulic fluid from said gallery to said hydraulic porting; and at least on relief valve associated with said gallery for diverting said high pressure hydraulic fluid from said gallery to said sump. An apparatus for transmitting power from a vehicle engine to an output shaft, comprising: a housing; a hydrostatic transmission disposed substantially within said housing, said hydrostatic transmission comprising a center section having hydraulic porting formed therein; a pump mounted on said center section and drivingly linked to said vehicle engine; and a motor mounted on said center section and hydraulically connected through said hydraulic porting to said pump, said motor being drivingly connected to said output shaft; a sump containing hydraulic fluid in flow communication with said hydrostatic transmission for supplying hydraulic fluid thereto; a porting plate disposed substantially adjacent to the external surface of said housing having internal porting formed therein, said internal porting being in flow communication with said hydraulic porting; a charge cover mounted over said porting plate; and a charge pump in flow communication with said internal porting mounted between said porting plate and said charge cover.