A machine tool including a fixed cover and a movable cover for covering at least part of a machining region includes a cover control device that includes a driving circuit for driving the movable cover, an abnormality detection device that detects an abnormality while the movable cover is driven, a self-diagnosis device that performs evaluation on whether the abnormality detection device is normal, and an output device that outputs a result of the evaluation by the self-diagnosis device. The self-diagnosis device is configured to perform the evaluation on whether the abnormality detection device is normal based on an operating state of the abnormality detection device at a time when a pseudo abnormality is generated on the movable cover by driving the movable cover via the driving circuit.

A rotary part of a pump (200) is connected to a body member (110) to be rotatable together. When the body member is attached to a main shaft (20) of a machine tool (10), a rotation stopping pin (310) of a rotation stopping device (300) fits in a fitting hole (41) of the machine tool and abuts on a wall surface (41a) of the fitting hole, whereby the rotation stopping pin and a rotation stopping lever (340) axially move against an elastic force of a spring (320) and the rotation stopping lever disengages from an engagement hole (113) in the body member such that the body member becomes rotatable relative to a support part (150, 160) that rotatably holds the rotary part. A force detecting sensor (50) outputs a force detection signal indicating a force with which the rotation stopping pin is pressing against the wall surface.

To provide an arrangement capable of detecting spindle failure in a machine tool using an existing servo control device, without providing separate external sensors, a failure analysis device or the like. A servo control device (22), which detects failure of a spindle of a machine tool including the spindle, a feed shaft, and a positioning servomotor that is installed to the feed shaft and is for deciding the position of the spindle, includes: a feedback acquisition unit (222) that acquires a feedback signal of the positioning servomotor; and an analysis/detection unit 226 that analyzes the feedback signal acquired to detect failure of the spindle.

A bearing diagnostic device includes an identification unit and an obtaining unit. The identification unit is configured such that a feature quantity, an operation condition of a main spindle at a measurement of the feature quantity, and specification data of the bearing used for the main spindle are preliminarily configured as inputs. The identification unit is configured such that a normal state and an abnormal state are preliminarily configured as outputs. The identification unit is configured to create an identification model through machine learning. The obtaining unit is configured to obtain the feature quantity, the operation condition at the measurement of the feature quantity, and the specification data of the bearing used for the main spindle.

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 machining status display apparatus includes a display device having a display screen, a stability lobe picture creator creating, based on specifications of a tool to be used, display picture data for displaying a stability lobe as a correlation diagram between a spindle rotation speed and a limit depth of cut of the tool above which regenerative chatter occurs, a first machining information picture creator creating display picture data for displaying machining related information other than regenerative chatter corresponding to set machining conditions, and a display controller displaying the stability lobe and the machining related information with the stability lobe and the machining related information superimposed one on another on the display screen of the display device based on the display picture data created by the stability lobe picture creator and the display picture data created by the first machining information picture creator.

In a method of monitoring a condition of a machine tool (1) with a plurality of machine axes, a test cycle is carried out in which at least some of the machine axes are actuated and associated condition data are determined. Based on this, a condition diagnosis is carried out in which the condition data are compared with reference quantities. The reference quantities are determined from reference condition data obtained in a plurality of reference test cycles on a plurality of reference machines (2, 3, . . . , n).

A machine tool according to the present invention is provided with a door opening/closing device including a movable door, a door opening/closing drive motor configured to drive the movable door, a power transferring mechanism configured to transfer power of the door opening/closing drive motor to the movable door. The machine tool includes a disturbance torque estimation unit configured to estimate a disturbance torque applied to the door opening/closing drive motor at an opening/closing operation of the movable door, a torque comparison unit configured to compare the disturbance torque estimated by the disturbance torque estimation unit to a predetermined first upper limit and a predetermined first lower limit, and a motor stop unit configured to stop the opening/closing operation of the movable door when the torque comparison unit determines that the disturbance torque is larger than the first upper limit or smaller than the first lower limit.

The disclosure describes a rotary union that includes a housing, a rotating machine component supported in the housing, a rotating seal member associated with the rotating machine component, a non-rotating seal member slidably and sealably disposed within the housing adjacent the rotating seal member, an expandable seal disposed between the non-rotating seal member and the housing, and an internal clamp disposed within an end portion of the expandable seal such that the end portion of the expandable seal is compressed between the internal clamp and the bore of the housing.

The disclosure describes A rotary union that includes a housing having a fluid inlet, a rotating machine component rotatably supported in the housing, a rotating seal member associated with the rotating machine component, a non-rotating seal member slidably and sealably disposed within the housing adjacent the rotating seal member, and an expandable seal disposed between and sealably engaging each of the non-rotating seal member and the housing. The expandable seal includes two end portions, one of the two end portions engaged to the non-rotating seal member and the other of the two end portions engaged to the housing, and an expandable portion disposed axially between the two end portions, the expandable portion having an axial length that varies based on a pressure of a hydraulic fluid that is present at the fluid inlet.