A rolling bearing apparatus includes: a bearing portion having an inner ring, an outer ring, a plurality of balls, and a cage; and a lubrication unit that is provided adjacently to an annular space formed between the inner ring and the outer ring and that has a pump that feeds a lubricant into the annular space. The pump has a main body portion having an internal space in which the lubricant is retained and being open at one end of the main body portion, a metal diaphragm fixed to a fixation portion that is a part of the main body portion so as to close the opening of the main body portion, and a piezoelectric element fixed to the diaphragm. At least the fixation portion of the main body portion is formed of metal, and the fixation portion and the diaphragm are fixed together by metal joining.

A throttle unit is equipped with a grooved block including at least one minute groove formed on a plane surface, and an opposite block having a plane surface which is opposite to the minute groove. The grooved block and the opposite block are detachably joined so as to be opposite to each other. A throttle fluid path is formed by the minute groove and the plane surface of the opposite block. At least one surface of each of the minute groove is constituted by a curved surface or an inclined surface that is inclined with respect to the plane surface of the grooved block.

The invention provides a machine tool capable of facilitating a switching between a guide bush mode and a non-guide bush mode. A machine tool comprises a headstock provided with a main spindle for gripping a workpiece, a rail extended along a main spindle axis, a first bearing fixed to the headstock and guided on the rail, a second bearing fixed to the headstock on the front side of the first bearing and guided on the rail, a supporting bed on which a guide bush is removably mounted, and a guide mounted on the supporting bed to movably support the headstock in a direction of the main spindle axis when the guide bush is removed. The rail provides a larger play on the second bearing when the headstock is supported by the guide than when the headstock is not supported by the guide.

This invention describes several mechanisms that increase the value and usability of 3D printing and assembly machines.

A bearing device includes a rolling bearing having an outer ring and an inner ring, an outer ring spacer disposed adjacent to the outer ring, and an inner spacer disposed adjacent the inner ring. The outer ring and the outer ring spacer are fitted to a housing, and the inner ring and the inner ring spacer are fitted to a rotary shaft. The outer ring spacer is provided with a nozzle, which is configured to inject a cooling fluid (R) toward an outer circumferential surface of the inner ring, and is inclined so that an injection port thereof is inclined forwardly in a rotation direction of the inner ring. An inclination angle a of the nozzle with respect to an axial direction is set to a value within a range from 50° to 90°.

A processing apparatus includes a processing unit. The processing unit includes a spindle, a spindle housing having an air bearing for rotatably supporting the spindle by using air, and a tool mounted on the front end of the spindle. The spindle housing has an air supply passage for supplying air to the air bearing, an air supply port connected to the air supply passage, an air discharge passage, and an air discharge port. The air supply port is connected through an air supply line to an air source. The air supply line is provided with a pressure gauge and a flowmeter. A first allowable value is previously set for the pressure to be detected by the pressure gauge, and a second allowable value is previously set for the flow rate to be detected by the flowmeter.

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.

A tool holder of a machine tool, in which the machine tool includes a spindle head and a spindle supported by the spindle head, includes: a shank portion attached to the spindle; a rotary portion integrally provided to the shank portion and to which a welding tool (processing tool) used for friction stir welding is attachable; a bearing mechanism (bearing) supporting the rotary portion so that the rotary portion is rotatable; and a bearing holder holding the bearing mechanism, in which the bearing holder is disposed facing the spindle head and is capable of transmitting a load applied to the bearing mechanism to the spindle head.

A spindle-bearing protecting device is provided that captures an indication of failure of the spindle bearings of a machine tool and can prolong the time until the main bearing is scorched. A spindle-bearing protecting device for protecting a bearing that supports a spindle to be rotatable, includes: a rotating part provided more to an outer side in an axial direction than the bearing, and having a rotor blade that rotates along with the spindle; a supply part that supplies coolant or lubricant to between the rotor blade and the bearing; a detection unit that detects abnormality of the bearing; and a control unit that controls a supply of coolant or lubricant by way of the supply part and the revolution speed of the spindle, in a case of the detection unit detecting abnormality of the bearing.

A sliding linear bearing includes a guide shaft on which a slider is movably guided in a guide direction. Bushes are inserted between the guide shaft and the slider including a main bush that is fixedly attached to the slider and a preloading bush that is held so as to be rotatable relative to the slider about the guide direction while being preloaded with a torque. The main bush and the preloading bush are preloaded by the torque in opposite directions of rotation without play relative to the guide shaft. A contact region between each of the bushes and the guide shaft blocks rotation about the guide direction between the slider and the guide shaft in both directions of rotation.