A woodworking spindle has a spindle shaft disposed in a spindle housing. One or more rotary bearings support the spindle shaft in the spindle housing. One or more temperature sensors are provided that detect the temperature of the one or more rotary bearings. An evaluation unit is provided and temperature signals generated by the temperature sensors are supplied to the evaluation unit that generates output signals based on evaluation of the temperature signals generated by the temperature sensors. In a method for monitoring the temperature of rotary bearings of a spindle of a woodworking machine, the temperature of the rotary bearings is permanently detected and rotary bearing temperature signals are generated. The rotary bearing temperature signals are sent to an evaluation unit and compared with a first temperature limit value. A first output signal is generated when the temperature signals reach a first temperature limit value.

The invention relates to a tool post of a machine tool, which tool post is capable of receiving a cutting insert for machining a component, characterised in that it comprises at least one sensor capable of determining a parameter representative of a cutting action between a component to be machined and a cutting insert, and a support housing (9) which is electrically connected to the sensor and comprises a battery (17) and a printed circuit board (19) supplied with current by said battery (17), wherein said printed circuit board (19) supports, at least partially, a radio transmission unit (11) and the housing (9) consists of a base (21) and a cover (23) which can be detached from one another, and in that the battery (17) is supported by the cover (23) and the printed circuit board (19) by the base (21) or vice versa.

An embodiment of the present invention provides a machining system that can lengthen the lifespan of a tool and improve the machining quality of a workpiece by managing the amount of wear of the tool by machining the workpiece using the other portion of the tool when a portion of the tool is worn and the machining performance of the tool is decreased. The machining device for controlling a tool position considering tool wear according to an embodiment of the present invention includes: a tool-moving unit coupled to the machining unit and moving the machining unit to change the position of the tool with respect to the workpiece; a supporting unit supporting the workpiece and moving the workpiece to change the position of the workpiece with respect to the tool; a sensor unit disposed at the machining unit and measuring a current amount, which is supplied to a machining motor operating the tool, or an operation force of the tool; and a control unit receiving a measurement signal from the sensor unit and transmitting a control signal to the tool-moving unit and the supporting unit.

A thermal displacement compensation apparatus includes a temperature measuring unit, a thermal displacement estimating unit, a thermal displacement compensation unit, a displacement measuring unit, a data recording unit, a thermal displacement compensation learning unit, and a displacement measurement timing diagnostic unit. The displacement measuring unit measures a displacement of a machine tool after compensating an axis command value. The thermal displacement compensation learning unit determines a thermal displacement estimation formula based on temperature information and the displacement recorded in the data recording unit. The displacement measurement timing diagnostic unit compares the temperature information at a past displacement measurement recorded in the data recording unit with current temperature information obtained from the temperature measuring unit, and determines whether to measure the displacement by the displacement measuring unit or not at a predetermined diagnosis timing.

Tool bodies, tools and machines for operating the tool include electronic circuits for providing data, collecting data, analyzing data and for controlling machines based on such data. Tool bodies and tools may include electronic circuits having data collecting sensors, which may be embedded in a housing with the electronic circuit and/or positioned outside of such a housing. Sensors include temperature sensors, motion sensors, strain sensors, moisture sensors, electrical resistance sensors, position sensors, antennas, and other components.

To provide an abnormality determination apparatus, a computer readable medium, an abnormality determination system and an abnormality determination method which can simply detect an abnormality of a temperature in a machine tool without incurring cost. An abnormality determination apparatus which determines abnormality of a temperature sensor in a plurality of machine tools, in which the plurality of machine tools is equivalent machine type, is arranged in equivalent environments, are provided with a temperature sensor at equivalent positions, the abnormality determination apparatus including: a temperature data acquisition unit which acquires temperature data outputted by the temperature sensors from each of the plurality of machine tools; a comparison unit which compares the temperature data acquired by the temperature data acquisition unit; and an abnormality determination unit which determines abnormality of the temperature sensor based on a comparison result by the comparison unit.

A measuring device is adapted for measuring a change of linear dimension of a shaft body of a bearing device along an axis due to thermal expansion. The measuring device includes a stationary seat and a strain unit. The strain unit includes an actuator and a strain member. The actuator is adapted to be mounted to the shaft body, and is movable relative to the stationary seat along the axis as a result of the change of linear dimension of the shaft body. The strain member is deformable, is secured to the stationary seat and is connected to the actuator such that movement of the actuator along the axis results in a force applied to the strain member which deforms the strain member.

A holder may include a base, an antenna and a sensor. The base has a bar shape extended along a central axis from a first end toward a second end. The base may include a metal member and a first resin. The metal member may include a pocket that is attachable of an insert including a cutting edge. The first resin may be located closer to the second end than the metal member. The antenna may be covered with the first resin. The sensor may be located closer to the pocket than the antenna and may be wired connected to the antenna, and may be measurable a state of the base. This configuration may contribute to solving the problem that handling of wiring becomes complicated.

Provided is a machine tool (1) which is capable of measuring machining accuracy of a workpiece (W) with high accuracy and enables the time required from machining to measurement of machining accuracy to be greatly reduced. The machine tool (1) machining a workpiece (W) while moving a tool and the workpiece (W) relative to each other includes a cover (2) separating from outside a machining area for machining the workpiece (W) therein, and temperature adjusting means (30) used in machining of the workpiece (W) to adjust an ambient temperature of the machining area.

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.