A machine tool (1) includes a spindle (32) supported on a support surface (37a) of a support body (37) with such an orientation that the longitudinal axis of the spindle extends along the support surface (37a). The spindle (32) is movable in a vertical direction that is perpendicular to the longitudinal axis of the spindle (32). The support body (37) is provided with a ventilation hole (80) extending through the support body (37) between the support surface (37a) and a surface (37b) facing in the direction opposite to the support surface (37a), to open toward the spindle (32).

A spindle device is mountable with a tool holder, and includes a rotating spindle rotatably mounted to a spindle main body and extending axially to have an axial end surface. A contactless power transmission module is disposed on a flange end surface of the spindle main body and an outer peripheral wall of the rotating spindle for supplying power. An electrically connecting module includes two conductive units each disposed in the rotating spindle and electrically connected with the power transmission module. Each conductive unit has an electrically conductive post extending axially and exposed from the axial end surface for conducting the power to the tool holder.

A clamping device for releasably holding a tool holder shank is formed with an engagement bore in a rear end. The clamping device includes a housing having a mounting bore for receiving the tool holder shank; a drawbar being mounted reciprocally movable inside the housing and which in a forward end is provided with an engagement segment which is arranged to engage with an engagement formation inside the engagement bore of the tool holder shank, wherein the drawbar is in a rear portion formed with a drawbar aperture extending through the drawbar, and a cam shaft extending through the drawbar aperture and comprising a cam formation. The cam shaft is rotatably journalled in the housing and arranged to impart an axial displacement to the drawbar in relation to the housing by the cam formation when rotating the cam shaft. The cam shaft includes two identical cam formations, which are spaced apart by a recess, and the drawbar is on the inside of the aperture formed with a ridge on each side of the aperture which each fits in the recess of the cam shaft when rotating the same.

Provided is a main spindle mechanism for a machine tool such that even in the case of a small-diameter spindle, it is possible to increase the torque transmitted to a large cutter and it is possible to prevent contact to and collisions with the workpiece. The main spindle mechanism, which is provided to a machine tool that cuts a workpiece by means of a cutter, is characterized by having: a spindle that transmits torque from the drive power source of the machine tool and is formed with outer teeth at the outer periphery of the tip thereof; a large cutter arbor provided with a shaft for attaching the large cutter and a base at which outer teeth are formed having the same diameter as the outer teeth of the spindle; and a gear-coupling-shaped sleeve that is provided in a manner so as to cover the base of the large cutter arbor and the tip of the spindle, and at which are formed inner teeth that mesh with both the outer teeth of the spindle and the outer teeth of the large cutter arbor.

A system and method can support in-memory session replication in a server cluster using a lazy deserialization approach. The server cluster can include a primary application server and a secondary application server. The primary application server operates to receive a request associated with a session from a client and maintains session information associated with the session. Based on the session information, the primary application server can responds to the client. The secondary application server operates to receive and maintain serialized session information from the primary application server. The secondary application server operates to update the serialized session information based on one or more session updates received from the primary application server. When the primary application server fails, the secondary application server can generate deserialized session information based on the updated serialized session information and responds to the client.

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 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 motor spindle having a first electromagnetic drive system including a stator unit and a rotor unit which can rotate about an axis of rotation and has at least one rotor shaft and a tool receiver for receiving a machining tool. At least one bearing unit provides rotationally mounting of the rotor unit in the stator unit. The tool receiver is arranged in an end region of the rotor unit. The stator unit has a stator housing with an end section arranged in the end region of the rotor unit. The stator unit comprises at least one motor, having a second electromagnetic drive system, with a stator and a rotational rotor, wherein the rotor has at least one rotational housing element of the end section of the stator unit.

A main spindle device for a machine tool that checks the seating of a tool holder using compressed air, wherein the main spindle device for a machine tool comprises: a main spindle that has a distal end face in close contact with a flange end of the tool holder; an annular recess that is formed on the distal end face of the main spindle so as to be covered by the flange end of the tool holder; an air supply flow channel that is linked to the annular recess and that supplies compressed air to the annular recess; a compressed air source that supplies air to the air supply flow channel; and a pressure detector that detects the pressure of the compressed air in the air supply flow channel. The annular recess has a first section and a second section that is deeper than the first section, and the air supply flow channel is opened to the second section.

The inventive working spindle comprises a spindle housing and a spindle shaft with axial positioning surface and axial contact surface by which the correct axial position of each fitting provided spindle shaft in the spindle housing is obtained. For torque-proof holding of the spindle shaft in the spindle housing, preferably with stationary motor, a braking unit is provided that comprises a radial outer part that is coupled with the spindle housing in a torque-proof manner and a radial inner part that is coupled with the spindle shaft in a torque-proof manner. The largest outer diameter of the peripheral surface of the inner part is smaller than the narrowest location of the through-opening of the spindle housing between the braking unit and the tool side end of the spindle housing. For this reason the spindle shaft can be readily removed from the spindle housing without disassembly measures of the braking unit, if required, and can be reinserted in reverse route. The inventive working spindle is simply constructed and can be versatilely used. Concurrently it is remarkably easy to maintain.