Hydraulic drive for petroleum pump - has electric motor with set of oil pumps and motors feeding oil to actuator for petroleum pump

摘要

The hydraulic drive has a cylinder (20) with piston (21) which is raised or lowered by oil pressure from pipe (19). This is fed with oil from a tank (12) via pump (17), coupled to a flywheel (16). The flywheel is driven by a hydraulic motor (14), supplied with oil from a second pump (11) driven by an electric motor (10). The oil circuit for the second pump and hydraulic motor uses the same tank as the first pump. The hydraulic motor works at constant volume flow. The flywheel has a speed sensor (34), operating a control element on the second pump to keep the speed within fixed limits. ADVANTAGE - Improved efficiency.