摘要 |
<p>The invention discloses a combination of a variable-speed engine-driven torque converter (18, 20, 22) which, in turn, powers a hydrostatic drive or any other type of hydraulic pump (24). Gear, piston, orbital, variable-displacement, single-stage, multiple-stage, and other types of pumps may be used to drive any type of hydraulic motor or servo. Including a multiple-stage pump permits automatic down-shifting when the load increases and automatic up-shifting when the load decreases. It also allows the operator to avoid lugging the engine, an important consideration, particularly with air-cooled engines. Engine (12) power is delivered to the pump via a torque converter, preferably a commercially available two-part torque converter assembly equipped with variable effective diameter split sheaves interconnected by a belt. The torque converter output drives a hydraulic pump via a shaft. The pump output is delivered to one or more hydraulic motors (30) that turn the wheels (32) of a vehicle.</p> |