Displacement device with a modular system of displacement units

摘要

A displacement device with a first part (1) and a second part (3) which are mutually displaceable in a displacement direction. The first part (1) comprises a number of contact bodies (7) which are pressed against the second part (3) against a pretensioning force which is present between the first part (1) and the second part (3). The contact bodies (7) are movable stepwise relative to the first part (1) and are also displaceable perpendicularly to the displacement direction. A stepwise movement of the contact bodies (7) causes the first part (1) and the second part (3) to be displaced relative to one another in the displacement direction under the influence of a friction force present between the contact bodies (7) and the second part (3), while the first part (1) and the second part (3) are supported in an accurate position relative to one another perpendicular to the displacement direction through a displacement of the contact bodies (7) perpendicular to the displacement direction. The contact bodies (7) thus have a dual function. In a special embodiment, the contact bodies (7) have a spherical contact surface (23), the stepwise movement of the contact bodies (7) being a pure rolling motion of the spherical contact surface (23) over the second part (3). The displacement device according to the invention is used in an X-Y table provided with an object table (99) which is displaceable relative to a base (95) parallel to an X-direction and parallel to a Y-direction which is perpendicular to the X-direction by means of the displacement device. The displacement device according to the invention is further used in a spindle device provided with a shaft (121) which is rotatable in a bearing bush (117) and is displaceable in an axial direction relative to the bearing bush (117) by means of the displacement device.