In a temperature estimation method, a rotational speed of a spindle is acquired. Moreover, a temperature rise table and a temperature fall table are used to calculate a temperature of a bearing from the rotational speed of the spindle every time a fixed time elapses. The temperature rise table stores in an associated manner the rotational speed of the spindle and a temperature rise of the bearing due to rotation of the spindle in a predetermined fixed time. The temperature fall table stores in an associated manner the temperature of the bearing and a temperature fall of the bearing due to heat dissipation in the fixed time.

In a temperature estimation method, a rotational speed of a spindle is acquired. Moreover, a temperature rise table and a temperature fall table are used to calculate a temperature of a bearing from the rotational speed of the spindle every time a fixed time elapses. The temperature rise table stores in an associated manner the rotational speed of the spindle and a temperature rise of the bearing due to rotation of the spindle in a predetermined fixed time. The temperature fall table stores in an associated manner the temperature of the bearing and a temperature fall of the bearing due to heat dissipation in the fixed time.

A method for processing a workpiece by using a diamond tool comprising nano-polycrystalline diamond or vapor-phase synthesized single crystal diamond, the nano-polycrystalline diamond comprising 10 ppm or more and 1000 ppm or less of nitrogen atoms, the vapor-phase synthesized single crystal diamond comprising 1 ppm or more and 100 ppm or less of nitrogen atoms, in processing the workpiece, the diamond tool having a temperature of 400 C. or lower at a contact point of the workpiece and the diamond tool, a spatial region within a distance of 3 cm from the contact point having an oxygen concentration of 20% or less.

A machine tool is provided capable of detecting an abnormality caused by detaching a spindle. The machine tool includes: the spindle configured to rotate a workpiece or a tool; a sensor configured to output a signal according to a rotation angle of the spindle; and a controller configured to detect occurrence of an abnormality in at least one of the spindle and the sensor when an electrical signal different from the signal output during each of rotation of the spindle and halt of the spindle is output from the sensor.

A machine tool is provided capable of detecting an abnormality caused by detaching a spindle. The machine tool includes: the spindle configured to rotate a workpiece or a tool; a sensor configured to output a signal according to a rotation angle of the spindle; and a controller configured to detect occurrence of an abnormality in at least one of the spindle and the sensor when an electrical signal different from the signal output during each of rotation of the spindle and halt of the spindle is output from the sensor.

An abnormality factor identification apparatus includes a sensor signal obtaining unit that obtains sensor signals associated with the physical state of a machine, an operating state determination unit that determines operating states of the machine based on information obtained from the machine, an abnormality level calculation unit that calculates the abnormality levels of the sensor signals for each operating state of the machine determined by the operating state determination unit, and a factor identification unit that determines a factor in an abnormality in the machine from historical data being a series of the abnormality levels for each operating state.

A spindle with intelligent auto-detection system may comprise a spindle, a shell configured for covering the spindle, a first conducting ring, a second conducting ring and at least a sensor. The spindle has a connecting section and a working section, and the connecting section is configured for connecting a power unit of a processing machine. Moreover, a tool is secured on the working section, and the sensor is positioned in an inner tube of the spindle. The first conducting ring and the second conducting ring in a recess of the shell are respectively electrically connected to the sensor and an analytical instrument. When the spindle is spinning, the sensor is adapted to measure various data of statuses of the spindle and the processing machine, and the obtained data is configured to be sent to the analytical instrument, thereby achieving monitoring effect.

A method for detecting at least one tool state of a tool of a machine tool for machining workpieces, which includes at least one tool holder, at least one positioning drive, which includes at least one tool which is arrangeable or arranged rotationally fixed in the tool holder and which includes at least one control unit. The method includes the following steps: detecting or providing tool and/or workpiece data in the storage means and/or the control unit; providing at least one reference drive frequency of the rotary drive and/or the positioning drive; detecting at least one ACTUAL driving frequency of the rotary drive and/or the positioning drive; assigning the ACTUAL drive frequency of a reference drive frequency of the rotary drive and/or the positioning drive by the control unit and evaluating and/or interpreting at least the reference drive frequency associated with the ACTUAL drive frequency by the control unit.

To provide a machine tool and a control device for the machine tool that can smoothly cut a workpiece while segmenting chips by feeding a cutting tool in a feed direction while reciprocally vibrating the cutting tool along the feed direction on the basis of a condition set by a user. The machine tool (100) or the control device (C) includes the control section (C1) that determines a number of rotations of the relative rotation and a number of vibrations of the reciprocal vibration per rotation of the relative rotation when the workpiece (W) is machined in accordance with a vibration frequency dependent on a period in which an operating instruction can be executed.

To provide a machine tool and a control device for the machine tool that can smoothly cut a workpiece while segmenting chips by feeding a cutting tool in a feed direction while reciprocally vibrating the cutting tool along the feed direction on the basis of a condition set by a user. The machine tool (100) or the control device (C) includes the control section (C1) that determines a number of rotations of the relative rotation and a number of vibrations of the reciprocal vibration per rotation of the relative rotation when the workpiece (W) is machined in accordance with a vibration frequency dependent on a period in which an operating instruction can be executed.