The invention relates to a drive unit for elevators consisting of a motor mounted in a casing, the motor driving a traction sheave via a drive shaft, there being a braking device to hold the traction sheave.
From the German patent specification DD 44 278 an electric elevator motor has become known which has a traction sheave and brake drum which are fastened together. The traction sheave and brake drum are mounted outside both the motor casing and the bearing closest to the motor on the free end of a shaft in an overhung manner. The traction sheave and the brake drum can be constructed in one piece. The brake, which has two shoes, consists of an actuating device, brake arms, and brake shoes, the actuating device being fastened on the outside of the casing of the motor. To support the heavy loads occurring on the side closest to the traction sheave there is a bearing plate and a bearing for heavy loads.
A disadvantage of the known device is that the overhung arrangement of the traction sheave and brake drum necessitate an expensive bearing plate and bearing for heavy loads. A further disadvantage is having the brake arms and brake shoes arranged at the sides, which increases the diameter of the drive unit.
The present invention concerns a drive unit with a narrow construction for use with an elevator.
The advantages resulting from the invention relate mainly to the fact that the drive unit is narrow in the direction at right angles to the drive shaft, and that the narrow construction makes it possible for the drive unit to be built into an elevator hoistway, for example in the space between the path of travel of the car and the wall of the hoistway. A further advantage lies in the common support of the traction sheave and drive shaft. There is no unsupported free end of a shaft, the traction sheave being supported directly on the bearing plate. As a result, bending forces on the drive shaft can be avoided.