A spindle structure capable of accelerating the flow of a fluid in through holes of a rotor. The spindle structure includes a rotatable rotation part. The rotation part includes a tool holding part provided at an axial direction one end of the rotation part and through holes that penetrate the rotation part and open at the end in the axial direction. Further the spindle structure includes a vane provided in the through holes. When the rotation part rotates, the vane rotates with the rotation part to allow a fluid in the interior of the through holes to flow toward the end in the axial direction.

A hand held machine tool for machining workpieces, comprising a housing in which a motor driving a rotor shaft is accommodated, and having an air guide region formed in the housing for supplying cooling air to the motor along a main flow direction oriented substantially parallel to the motor longitudinal axis. The air guidance region is limited at one end by at least one air inlet and at the other end by at least one air outlet for discharging the cooling air from the housing. A separator is arranged in the air guide region for dividing the cooling air into an outer partial air flow flowing around the outer circumference of the motor and into an inner partial air flow flowing through the motor. The separator is formed such that a degree of contamination of the outer partial air flow is greater than a degree of contamination of the inner partial air flow.

Provided is a cooling structure for a bearing device. The bearing device includes a rolling bearing having a stationary raceway ring and a rotating raceway ring, a stationary spacer adjacent to the stationary raceway ring and a rotating spacer adjacent to the rotating raceway ring. The stationary raceway ring and the stationary spacer are provided in a stationary member, and the rotating raceway ring and the rotating spacer are provided in a rotating member. The cooling structure includes: an annular recessed portion provided on a circumferential surface, of the stationary spacer, that confronts an opposite spacer; and a nozzle hole configured to inject a compressed air from an outlet open to a bottom surface of the recessed portion toward a circumferential surface of the rotating spacer that confronts an opposite spacer. The nozzle hole is inclined forwardly in a rotation direction of the rotating spacer.

A constant temperature water supply apparatus includes a temperature adjustment unit that circulates cooling water and adjusts the temperature of a spindle unit of a processing apparatus and a processing water temperature adjustment unit. The temperature adjustment unit includes a pump that sends the cooling water to the spindle unit, a cooling water cooling unit, a first pipe that connects the pump and the cooling unit, a second pipe that connects the cooling unit and the spindle unit, and a third pipe that connects the spindle unit and the pump. The processing water temperature adjustment unit includes a processing water pipe that has one end connected to a water source and supplies processing water from the other end side to a processing tool and a heat exchange unit on the processing water pipe.

A drive shaft for a machine tool, for example a core drilling machine, able to be connected to a drilling tool, in particular a core bit, is disclosed. The drive shaft contains a cavity which substantially extends over the whole length of the drive shaft and along the rotational axis. The cavity contains at least one inflow opening where, through the at least one inflow opening, water can be fed along the drive shaft into the drilling tool. In the drive shaft, an insertion device is provided in the cavity, through which water is guided for cooling the drive shaft, firstly, in a first direction and then in a second direction, where the water comes into direct contact with the inner side of the cavity at least in the first direction.

A water temperature setting method for a processing apparatus for processing a workpiece held by a holding table by rotating at a high speed a spindle with a processing tool mounted thereto and supplying processing water to the processing tool. A set temperature for the processing water supplied to the processing tool is set to be higher than a set temperature for spindle cooling water supplied to a spindle unit that rotates the spindle at the high speed, in consideration of a lowering in temperature due to evaporation of the processing water scattered from the processing tool due to the high-speed rotation of the processing tool.

The invention relates to: sensor modules for e.g. a tool holder, wherein the sensor unit is integrated as a structural entity; tool or machine elements designed with such sensor modules; and a machining/machine tool comprising such a sensor module. The sensor modules have a sensor system for detecting system states or operating states which occur during the machining of a workpiece.

An electric power device may include a casing, a motor disposed within the casing, a control unit, and an air channel. The motor may be configured to operate a working implement of the device and may include a motor housing having at least one outlet through which air cooling the motor exits the motor housing. The air channel may be configured to enclose the at least one outlet of the motor housing. The air channel may provide a passage for the air drawn from outside the casing and through the motor housing out of the casing via an exhaust outlet disposed in the casing at an end of the air channel.

A spindle structure capable of accelerating the flow of a fluid in through holes of a rotor. The spindle structure includes a rotatable rotation part. The rotation part includes a tool holding part provided at an axial direction one end of the rotation part and through holes that penetrate the rotation part and open at the end in the axial direction. Further the spindle structure includes a vane provided in the through holes. When the rotation part rotates, the vane rotates with the rotation part to allow a fluid in the interior of the through holes to flow toward the end in the axial direction.

In a radiating structure for a main spindle having a tapered bore formed at a distal end of the main spindle, into which a tapered portion of a tool holder is mounted, a key fixing member provided with a drive key is fixed to the distal end of the main spindle, and the drive key is fit into a key groove formed in the tool holder. This configuration prevents a phase shift in rotation direction of the tool holder arising from rotation of the main spindle. A radiating member which exchanges heat with an ambient atmosphere is provided to the key fixing member provided with the drive key.