Patent ID: 8337169

Claim:
A system, comprising: a drive train; a compressor and a consumer coupled to the drive train and extracting energy therefrom; wherein the compressor executes a compression stroke and an expansion stroke during operation; wherein the consumer comprises a pump that is a displacement pump comprising at least one pump chamber providing pumping power absorbed by the consumer and at least one further pump chamber that provides a reduced or no pumping power depending on the operating conditions of the compressor; wherein the pump further comprises a stator in which is formed a discharge opening and an intake opening; a rotor arranged inside the stator, the rotor having a generally cylindrical shape with a flattened portion; wherein the rotor and stator form the at least one pump chamber and the at least one further pump chamber; wherein, when the flattened portion of the rotor faces the discharge opening and the intake opening formed in the stator, no contact occurs between the rotor and the stator; wherein the pump varies an absorption of power provided thereto by the drive train depending on the power required for operation of the compressor and supplied from the drive train to the compressor; and whereby a characteristic of a total power including the power required for operation of the compressor and power absorbed by the consumer is substantially constant during a compression stroke of the compressor.