Semi-rigid stator

A helical gear device, comprising:

• a rotor including one or more radially outwardly extending helical lobes;
• and
• a stator including:
• a stack of rigid rings, each of the rigid rings having:
• a front surface,
• a rear surface,
• an interior surface defining a central opening extending from the front surface to the rear surface, and
• an exterior surface, wherein each of the rigid rings is aligned along a common centerline, and each of the rigid rings is rotated slightly relative to each other such that the stack of rigid rings forms a helically convoluted chamber;
• a rigid stator housing, the stack of rigid rings being located within the rigid stator housing;
• and
• a deformable layer disposed between the exterior surface of each of the rigid rings and the cylindrical outer housing, wherein the deformable layer bonds the rigid rings together as the ring stack and permits radial displacement of the rigid rings, relative to each other, to permit a solid to pass between the rigid rings and the rotor.