Machining apparatus with mechanism for retaining axial position of guide member

A machining apparatus including a slide member on which a tool is mounted and a guide member for guiding the slide member, wherein a bearing is provided between a fixed base and the guide member, and a bearing is provided between the slide member and the guide member, and wherein the guide member and the slide member are adapted to move coaxially, and a mechanism for generating a thrust between the slide member and the guide member is provided, and wherein permanent magnets for reversing a moving direction of the slide member are disposed on the slide member and the guide member, respectively, so that a repulsive force in the moving direction of the guide member acts between the slide member and the guide member at each end position of a movement stroke of the slide member,

• wherein permanent magnets for retaining the guide member are disposed on the guide member and the base, respectively, to generate retaining forces for retaining an axial position of the guide member without contact between the guide member and the base,
• said retaining forces act between the guide member and the base, and the retaining forces are balanced in a vicinity of a center of a stroke of the guide member with respect to the base, and the retaining force for returning the guide member to the central position of the stroke is applied when the guide member is displaced from the vicinity of the center of the stroke.