초록 ▼

A vehicle includes at least a pair of drive wheels, each wheel being independently controlled by an integrated transmission, each transmission being powered by an input shaft operably driven by a common engine. Each transmission is of a type wherein a pump head with pistons is driven by the input sh

A vehicle includes at least a pair of drive wheels, each wheel being independently controlled by an integrated transmission, each transmission being powered by an input shaft operably driven by a common engine. Each transmission is of a type wherein a pump head with pistons is driven by the input shaft and conveys output fluid to a motor head which is driven thereby and rotates an output shaft. Pump head output is controlled by an operator variable swash plate. The transmission integrally includes a dampening mechanism for the swash plate, a positive neutral structure for the swash plate, an automatic parking brake with override mechanism to allow setting of the brake or release of the brake by the operator, a porting block communicating fluid flow between the pump heads and providing for overpressure relief, and a charge pump for communicating makeup fluid to the pump head and to circulate the fluid so as to cool same. The transmission also includes structure to provide for substantial internal gear reduction even at full output speeds.

대표청구항 ▼

In a hydraulic transmission wherein hydraulic fluid is variably pumped by a pump head and wherein a swash plate mounted in a fluid holding cavity controls fluid output of said pump head and further wherein said swash plate has a neutral orientation thereof such that said pump head has substantially

In a hydraulic transmission wherein hydraulic fluid is variably pumped by a pump head and wherein a swash plate mounted in a fluid holding cavity controls fluid output of said pump head and further wherein said swash plate has a neutral orientation thereof such that said pump head has substantially no fluid output and a plurality of non-neutral orientations such that said pump head has variable fluid outputs; the improvement comprising: (a) dampening means associated with said transmission and cooperating with said swash plate so as to partially resist movement of said swash plate from a first orientation thereof producing a first fluid output from said pump to a second orientation thereof producing a second different fluid output from said pump head; (b) said dampening means comprising a piston mounted within a receiver and having a piston head slidably engaging said swash plate; and including: (c) valve means to allow flow of fluid from said cavity into said receiver; and (d) restrictive means allowing fluid to flow in a restrictive manner from said receiver to said cavity thereby dampening movement of said swash plate toward said piston.