In a spindle device, a cover member covers a surface of a flange portion on the front side of the spindle shaft, the flange portion projecting radially outward from the outer peripheral surface of the spindle housing, and the outer peripheral surface of the spindle housing extending from the surface of the flange portion toward the front of the spindle shaft. In the cover member, a flow path for allowing a coolant to flow therethrough is formed.

A spindle device includes: a spindle housing; a spindle shaft configured to be rotatably supported inside the spindle housing; a spindle mount having an insertion cavity into which the spindle housing is inserted along the axial direction of the spindle shaft; a flange portion projecting outward from the outer peripheral surface of the spindle housing and configured to be removably fixed to an end of the spindle mount that is closer to one opening of the insertion cavity; and a support member configured to support the spindle housing inserted in the insertion cavity by using, as a base, the other end of the spindle mount that is closer to the other opening of the insertion cavity.

In a spindle device, a movable member is provided on a cover member, which is attached to a spindle housing and covers the outer peripheral surface of a chuck portion which is a disk-shaped rotating member. The movable member is moved by a gas flowing through a flow passage formed in the cover member and thereby brought into contact with the chuck portion. The movable member is electrically connected to a ground.

A machine tool capable of facilitating a process of mounting a fluid supplying unit to a spindle supporting unit is provided. The machine tool has a rotating unit including a spindle provided with a workpiece chucking unit, a supporting unit which rotatably supports the spindle around a spindle axis, and a fluid supplying unit removably mounted on a rear end of the supporting unit to allow fluid flow inside the spindle toward the chucking unit. The fluid supplying unit has an insert to be received in the rotating unit in the direction of the spindle axis. A labyrinth clearance is formed between the outer circumferential surface of the insert and the inner circumferential surface of the rotating unit when the fluid supplying unit is mounted on the rear end of the supporting unit. The labyrinth clearance allows rotation of the rotating unit and restricts leakage of the supplied fluid from inside the spindle when the rotating unit is rotated.

A positioning of a spindle with micrometric forwarding control and tilting of its rotation axis includes a spindle shaft rotatingly supported inside rotatable supports, wherein the rotatable supports include two spherical elements having housings which are eccentric with respect to the rotation axis that join the centers of the spheres, and wherein the two spherical elements are positioned in a cylindrical housing having at least two parts, and wherein two rotation elements are connected to the two spherical elements and cause their independent rotation.

The present disclosure relates to a grinding machine. More particularly, the present disclosure relates to a centerless grinding machine comprising a damping device. The present disclosure also relates to a spindle for a grinding machine, and to a damping device for a spindle of a grinding machine, particularly for a grinding spindle or regulator spindle of a centerless grinding machine, wherein the damping device comprises at least one damping unit including an auxiliary mass section, an elastic section and a damping section, which are integrated in the spindle, and which jointly define a damped vibratory system for increasing the dynamic stiffness of the spindle.

A guide bush adjusting device includes a drawbar (a mobile body) displaceable relative to a guide bush sleeve (cylindrical body). The drawbar is formed from a screw connection member (a connection member) which is connected to a guide bush housed in the guide bush sleeve (a cylindrical body), and an operation member configured to displace the screw connection member. The guide bush adjusting device adjusts an inner diameter of the guide bush by releasing the operation member from its fixation, displacing the drawbar, moving the guide bush with respect to the guide bush sleeve via the drawbar to thereby position the guide bush, and fixing the operation member of the drawbar (mobile body) at a predetermined position.