A rotary union that includes rotating and non-rotating machine components, each having a sealing ring, which can together form a mechanical face seal. A rotor disposed on the rotating machine component includes one or more magnets. A sensor array disposed in the housing includes a plurality of sensing elements that are integrated with a control device, a communication device, and a power storage device. The sensor array further includes a magnetic pickup coil disposed to closely overlap the outer periphery of the rotor. When the rotating machine component rotates, the magnet creates a rotating magnetic field that cooperates with the magnetic pickup coil to produce electrical power to operate the sensor array.

A tool spindle for machine tool includes a tool spindle having a front end in which a tool is mounted and installed to be rotatable, and a vibration damping device mounted in a rear end of the tool spindle to damp cutting vibration generated at the front end of the tool spindle, and including a rigid member coupled to the rear end of the tool spindle and a tuned mass member elastically supported by the rigid member.

A compressed fluid supply system comprises: a pressure adjustment unit for adjusting the pressure of a compressed fluid supplied from a fluid supply source to support members supporting a movable member so that the movable member can be driven through the use of the compressed fluid; a drive force acquisition unit for acquiring a drive force of a motor for driving the movable member; and a pressure control unit for adjusting the pressure of the compressed fluid supplied to the support members by controlling the pressure adjustment unit on the basis of the drive force of the motor.

A motor spindle including a sleeve-shaped stator, which has a first coupling receptacle and a second coupling receptacle, further including a rotor, which has a first coupling part with axial fixed bearing and a second coupling part with axial loose bearing, which are to be mounted to the respective coupling receptacle, the axial loose bearing comprising an inner ring mounted to the rotor shaft and an outer ring arranged coaxially with the inner ring and mounted to the second coupling part, wherein the second coupling part is received on the rotor shaft so as to be axially movable parallel to the rotor axis between a first functional position and a second functional position along an adjustment path and wherein for the entire adjustment path there is a first distance between a first axial surface of the inner ring and the second coupling part and there is a second distance between a second axial surface of the inner ring and the second coupling part.

A motor spindle including a sleeve-shaped stator, which has a first coupling receptacle and a second coupling receptacle, further including a rotor, which has a first coupling part with axial fixed bearing and a second coupling part with axial loose bearing, which are to be mounted to the respective coupling receptacle, the axial loose bearing comprising an inner ring mounted to the rotor shaft and an outer ring arranged coaxially with the inner ring and mounted to the second coupling part, wherein the second coupling part is received on the rotor shaft so as to be axially movable parallel to the rotor axis between a first functional position and a second functional position along an adjustment path and wherein for the entire adjustment path there is a first distance between a first axial surface of the inner ring and the second coupling part and there is a second distance between a second axial surface of the inner ring and the second coupling part.

A spindle device of a machine tool is provided with: a rear-side bearing and front-side bearings which rotatably support a spindle with respect to a housing; a built-in motor which is disposed around the spindle between the front-side bearings and the rear-side bearing; heat pipes which are embedded in the spindle and which transmit heat between the central part and the rear-end part of the spindle; a plurality of plate-like inner fins which are affixed to a rear part of the spindle that protrudes rearward of the rear-side bearing and which extend perpendicularly with respect to the rotation axis of the spindle; and a plurality of plate-like outer fins which are affixed to the housing and which are disposed between the plurality of inner fins in such a manner as not to contact the inner fins.

A spindle device of a machine tool is provided with: a rear-side bearing and front-side bearings which rotatably support a spindle with respect to a housing; a built-in motor which is disposed around the spindle between the front-side bearings and the rear-side bearing; heat pipes which are embedded in the spindle and which transmit heat between the central part and the rear-end part of the spindle; a plurality of plate-like inner fins which are affixed to a rear part of the spindle that protrudes rearward of the rear-side bearing and which extend perpendicularly with respect to the rotation axis of the spindle; and a plurality of plate-like outer fins which are affixed to the housing and which are disposed between the plurality of inner fins in such a manner as not to contact the inner fins.

Provided is a machine tool including: a movable drum base (4); a drum (5) that is incorporated in the drum base (4) and is circular in outline; and a quill main spindle (6) penetrating through the drum (5) in a central axis direction of the drum (5), wherein protrusion allowance from the drum (5) is adjustable, wherein a bearing provided along an outer circumference of the drum (5) is interposed between the drum base (4) and the drum (5) such that the drum (5) is rotatable in the drum base (4), and movement of the drum base (4), rotation of the drum (5), and protrusion allowance adjustment of the quill main spindle (6) from the drum (5) allow a tool (10) mounted on the quill main spindle (6) to be positioned.

Provided is a machine tool including: a movable drum base (4); a drum (5) that is incorporated in the drum base (4) and is circular in outline; and a quill main spindle (6) penetrating through the drum (5) in a central axis direction of the drum (5), wherein protrusion allowance from the drum (5) is adjustable, wherein a bearing provided along an outer circumference of the drum (5) is interposed between the drum base (4) and the drum (5) such that the drum (5) is rotatable in the drum base (4), and movement of the drum base (4), rotation of the drum (5), and protrusion allowance adjustment of the quill main spindle (6) from the drum (5) allow a tool (10) mounted on the quill main spindle (6) to be positioned.

A bearing apparatus includes a bearing that rotatably supports a main spindle around a rotation axis, a spacer including an inner-ring spacer adjacent to an inner ring of the bearing and an outer-ring spacer adjacent to an outer ring, and a heat flux sensor provided in an inside surface of the outer-ring spacer. A distance in a direction along the rotation axis from a center of the bearing to a center of the heat flux sensor is longer than 0.5 time and shorter than one time of a dimension of the bearing in the direction along the rotation axis.