Drive mechanism for drill

摘要

A drive mechanism for a drill provides both rotational drive and axial feed for a drill of substantial diameter such as those used to drill holes for roof bolts in mine shafts. A plurality of sprockets carry two chains of drive links which interlock around the drill shaft with each drive link having depressions which mate with scroll-like projections on the drill shaft. For axial feed, the sprockets are driven from worm drives in separate housings on each side of the chains, the worm drives being driven from gears in a gearbox which are connected through a differential gearset to a hydraulic motor. A second hydraulic motor also drives through the differential gearset to rotate the drill shaft and the entire drive chain assembly. A large diameter face seal serves as the partition between the chain drive assembly and the gearbox. The rotatable chain drive assembly includes openings between the worm drive housings to permit rock fragments and other debris which falls into the chain drive assembly to escape from the side without jamming the chain drive. A stationary housing which encloses the chain drive assembly includes openings to permit the egress of debris and also bars across the openings to prevent an operator from injury by inadvertently coming into contact with the rotating chain drive assembly.