An X-Y drive apparatus includes an X drive unit mounted on a stationary base and a Y drive unit mounted on an X table of the X drive unit. The X drive unit includes a first motor operatively coupled to the X table and a second motor operatively coupled to a splined shaft. A worm gear is mounted on the splined shaft such that the worm gear may move along the splined shaft slidably, but it does not rotate around the splined shaft. The Y drive unit includes a Y table and a ball screw which is operatively coupled to the Y table and which has a worm wheel in mesh with the worm gear.
