Vertical drive apparatus for storage and retrieval vehicles

Abstract

A novel vertical drive assembly for a storage and retrieval vehicle wherein a cable drive motor is horizontally juxtaposed between a lift cable winding and unwinding drum. The vertical drive assembly is modularly assembled on a frame and is attachable and detachable from the vehicle as a unit. The vertical drive assembly comprises, in seriatim, the motor, a belt drive sprocket wheel, a drive belt, a belt driven sprocket wheel, and, juxtaposed and on the same axis as the driven sprocket wheel, an input adapter, a speed reducer, and the drum. The motor is attached to the frame by jacks used to raise and lower the motor to adjust tension in the belt. To stay within the width of the vehicle, the input adapter and speed reducer are at least partly disposed within the core of the drum with the speed reducer providing a bearing for the drum. To reduce starting inertia, sprocket wheels are fabricated from lightweight material. Drum supports comprise louvered blades to induce air flow over the speed reducer when the drum rotates. In one embodiment, a concentric disc, spring actuated, electrically-released brake is mounted on the axis of the motor when the length of the combination motor and brake is less than the width of the vehicle. In another embodiment, a disc brake comprising pneumatic release and spring actuation is juxtaposed between the driven sprocket wheel and the input adapter. Interlocks prevent the vehicle from operating when air pressure is below a predetermined level.