Abstract: A relative motion between a solid propeller shaft and a sleeve surrounding the propeller shaft is utilized to control a pitch of a marine propeller; the front end of the sleeve being supported by a pair of taper roller bearings and the rear end of the sleeve being connected to the hub of the propeller. A bearing housing supporting the taper roller bearings is formed as a piston of a servomotor and a casing receiving the bearing housing is formed as a cylinder of the servomotor. The casing is formed as a common oil reservoir for feeding lubricating oil to a stern tube bearing and bearings in the hub of the propeller.