Patent ID: 9028228
Filing Date: 2015-05-12
Classification: F04D

Abstract:
1. A pump comprising: a pumping part which is mounted for rotation in a pumping chamber formed by a housing, rotation of the pumping part causing pumping of fluid within the pumping chamber; a drive shaft rotatable about a longitudinal axis; and a coupling to transmit rotational movement of the drive shaft about its longitudinal axis to the pumping part, to cause the pumping part to rotate, the coupling comprising a first part which is connected to the pumping part and a second part which is connected to the drive shaft; the first part being provided with an electrically conductive material and the second part being provided with an element for generating a magnetic field; the second part being moveable relative to the first part to vary a degree of interaction between a magnetic field generated by the element and the electrically conductive material; wherein movement of the second part relative to the first part is caused, at least in part, by a fluid controlled actuator which comprises a piston moveable within a cylinder which, in use, is substantially non-rotating, such that the drive shaft and the second part are rotatable relative to the cylinder.