Provided is an apparatus for machining a double enveloping worm shaft, and more particularly, to an apparatus for machining a double enveloping worm shaft, which cuts threads on a workpiece having a double enveloping body having a central portion formed therein in a concave arc-shaped outer circumferential surface and in which teeth of the machined double enveloping worm shaft are cut to a uniform depth while being always directed toward a central axis of a worm wheel, machining precision of the double enveloping worm shaft is increased, and thus post-machining is not required.

Provided is an apparatus for machining a double enveloping worm shaft, and more particularly, to an apparatus for machining a double enveloping worm shaft, which cuts threads on a workpiece having a double enveloping body having a central portion formed therein in a concave arc-shaped outer circumferential surface and in which teeth of the machined double enveloping worm shaft are cut to a uniform depth while being always directed toward a central axis of a worm wheel, machining precision of the double enveloping worm shaft is increased, and thus post-machining is not required.

The device is a precision motion right angle drive for use with linear and rotary stages which employs a combination of globoid worm and small diameter star gear. Coaxial with the star gear, on the same shaft, is a spur gear which drives the rotary stage gear or a linear rack. The thin star gear achieves meshing accuracy with the globoid worm permitting a large tooth angle for direct preloading without jamming. This gear combination eliminates backlash, allows a low gear ratio for low globoid worm speed, and enables the use of an ordinary spur gear to engage the stage gear without backdrive or backlash. Further, it allows for gear contact area to compensate for the thinness of the star gear. An embodiment including an integrated bearing rotary stage permits flexibility of application and avoidance of need for custom bearing designs by achieving high motion precision at low cost.

The device is a precision motion right angle drive for use with linear and rotary stages which employs a combination of globoid worm and small diameter star gear. Coaxial with the star gear, on the same shaft, is a spur gear which drives the rotary stage gear or a linear rack. The thin star gear achieves meshing accuracy with the globoid worm permitting a large tooth angle for direct preloading without jamming. This gear combination eliminates backlash, allows a low gear ratio for low globoid worm speed, and enables the use of an ordinary spur gear to engage the stage gear without backdrive or backlash. Further, it allows for gear contact area to compensate for the thinness of the star gear. An embodiment including an integrated bearing rotary stage permits flexibility of application and avoidance of need for custom bearing designs by achieving high motion precision at low cost.

The present invention relates to an apparatus and a method for machining a worm shaft of a double enveloping worm gear composed of a double enveloping worm shaft and a worm wheel, and enables X-axis movement of the worm shaft, Y-axis and Z-axis movements of a worm machining cutter, A-axis rotation of the worm shaft, C-axis rotation of the cutter, and B-axis tilting of a saddle on which the cutter is provided, and thus can facilitate worm shaft machining.

The present invention relates to an apparatus and a method for machining a worm shaft of a double enveloping worm gear composed of a double enveloping worm shaft and a worm wheel, and enables X-axis movement of the worm shaft, Y-axis and Z-axis movements of a worm machining cutter, A-axis rotation of the worm shaft, C-axis rotation of the cutter, and B-axis tilting of a saddle on which the cutter is provided, and thus can facilitate worm shaft machining.