Abstract: A drive mechanism for a belt conveyor system having a driven pulley and a belt trained thereon, the mechanism including a speed reducer disposed in the pulley and having coaxial input and output shafts, the output shaft being a reaction shaft for the rotatable housing of the speed reducer. The housing of the speed reducer is in axial alignment with the pulley and is connected thereto for driving the pulley. A brake is provided for restraining the rotation of the output shaft, and may consist of a disc rotatable with the output shaft and a hydraulically operated head controlled by a system including a pump driven by the output shaft in response to the load on the belt of the conveyor. The drive for the pump senses the load on the conveyor belt by the reaction response of the output shaft, thereby varying the rate at which the pressure in the hydraulic system increases to control the friction head indirectly in response to the conveyor load.