Control system for hydrostatic power transmission - has sprung stepped piston maintaining constant main and auxiliary pump pressure sum

摘要

The diesel engine drives a hydraulic pump which supplies fluid under pressure to the hydraulic motor. An auxiliary pump is driven by a belt from the engine. The pressure from the auxiliary pump acts on the large diameter piston which is connected to the small diameter piston. The pressure from the main pump acts on the small diameter piston through the pipe. The movement of the stepped piston is resisted by the spring so that the sum of the pressures delivered by the main pump and the auxiliary pump is constant. The system also includes the control mechanism which controls the stroke of the main pump.