Abstract: A pump having an inlet port, an outlet port and a pumping mechanism for pumping fluid from the inlet port to the outlet port. The pumping mechanism includes a carrier (2) that is provide with a plurality of pumping of pumping elements. The pumping mechanism also includes a flexible cam ring (6) surrounding the carrier and having an internal cam surface that is followed by the pumping elements. The cam ring is flexible so that the discharge flow rate of the pump can be varied by varying the shape of the cam ring. Also, a control device is provided for controlling the shape of the cam ring. The control device and one or more cam orifices for controlling fluid pressure.

Abstract: A rotary pump which is suitable for use as the pump for a vehicle power steering system has an integral motor. The pump includes a housing 16 through which a rotatable shaft 4 extends having at one end a pump rotor assembly 5. The pump rotor assembly 5 is in fluid communication with an oil cavity 15 which is in good thermal contact with the housing 16. The housing 16 functions as a heat sink. Mounted on the radially outer wall of the housing 16 is the stator 20 of the motor with the stator 20 also in good thermal contact with the housing 16. The rotor 26 of the motor is located radially outside of the stator 20 and has axially arranged magnets 27. The rotor 26 is connected to the rotatable shaft 4 by means of a radially extending wall 26b. The integral rotary pump and motor is very compact and straightforward to construct and is also capable of withstanding the heat generated by the motor components during the high demands of a vehicle steering system.