Fluid motor having fluid actuated advancing elements to advance an advanceable part of the fluid motor relative to a stator part of the fluid motor

摘要

A fluid motor includes a plurality of fluid actuated pistons 13 extending radially outwards from a stator and each having a cam follower bearing 14 at its outer end. A rotor surrounds the stator and includes an inwardly facing drive cam profile engaged by the cam follower bearings 14 to advance the rotor relative to the stator. The drive cam profile 8 is substantially sinusoidal as a result of which substantially constant torque is achieved.