Patent ID: 8851867

Claim:
A stator for a progressive cavity pump or motor, comprising: a stator housing; and a stator thread moulded within the housing, wherein the stator housing has a central axis and further comprises: an outer tube having a first end and a second end opposite the first end; an inner anchor element disposed within the outer tube and including a plurality of apertures extending radially therethrough, wherein the apertures provide access to one or more gaps radially disposed between the inner anchor element and the outer tube, wherein the stator thread extends through the apertures into the one or more gaps, and wherein a first end and a second end of the inner anchor element each comprise a first plurality circumferentially-spaced protrusions and a plurality of circumferentially-spaced indentations, one indentation being circumferentially disposed between each pair of circumferentially-adjacent protrusions of the inner anchor element; and a first end cap fixed to the first end of the outer tube; a second end cap fixed to the second end of the outer tube; wherein each end cap includes an interconnecting part having a second plurality of circumferentially-spaced protrusions and a plurality of circumferentially-spaced indentations, one indentation being circumferentially disposed between each pair of circumferentially-adjacent protrusions of each end cap; wherein the first plurality of protrusions at the first end of the inner anchor housing engage the plurality of indentations of the first end cap and the first plurality of protrusions at the second end of the inner anchor housing engage the plurality of indentations of the second end cap.