Disclosed is an angle grinder. An operation body is configured to control the polishing of an action head end, one end of a head housing is detachably connected to the operation body, the other end of the head housing is detachably connected to a front cover. One end of a rotor shaft extends out of the head housing and the front cover; a bearing is sleeved on the periphery of the rotor shaft; the front cover is located on the periphery of the bearing; and an installation stopper can be detachably installed on the rotor shaft and can rotate synchronously with the rotor shaft. One side of the bearing is in contact with the shoulder of the rotor shaft, and the other side of the bearing is contact with the installation stopper. The bearing can be clamped by the installation stopper and the shoulder of the rotor shaft.

A main spindle device for a machine tool has a hollow main spindle, which is supported by a housing such that the hollow main spindle can rotate. The main spindle device is provided with: an annular cylinder, which is fixed to the housing, and is formed extending into the main spindle, said annular cylinder having an opening formed in the axis line direction of the main spindle; and a cooling path formed on the outer circumferential surface of the cylinder to face the inner circumferential surface of the main spindle.

A fan-equipped motor includes: a motor for rotating a spindle, the motor including a hollow-shaped motor shaft in which a through hole is formed; and a fan for cooling the motor, the fan including a hollow-shaped rotary shaft in which a through hole is formed, and a plurality of blades attached to the rotary shaft, the fan being disposed on the side of the motor that is opposite to the spindle. The motor shaft and the rotary shaft are disposed so that cooling air produced by the fan flows in a different passage and in a different direction from a gas supplied into the through hole of the rotary shaft and flowing in the through hole of the motor shaft.

An impact tool includes a housing, an impact mechanism unit, a motor, and a dust collection fan. The housing is configured to mount a dust collection attachment. The impact mechanism unit is disposed inside the housing. The impact mechanism unit has a front end to which a tool bit is mounted and an impact element that reciprocates. The impact mechanism unit is configured to impact the tool bit by the impact element. The motor is disposed such that a rotation shaft of the motor intersects with an impact axis direction of the impact mechanism unit inside the housing. The dust collection fan is disposed on the rotation shaft. The dust collection fan is disposed below the motor.

A machine tool (1) includes a spindle (32) supported on a support surface (37a) of a support body (37) with such an orientation that the longitudinal axis of the spindle extends along the support surface (37a). The spindle (32) is movable in a vertical direction that is perpendicular to the longitudinal axis of the spindle (32). The support body (37) is provided with a ventilation hole (80) extending through the support body (37) between the support surface (37a) and a surface (37b) facing in the direction opposite to the support surface (37a), to open toward the spindle (32).

A power tool having air cooling for the components of the power tool. Here, the power tool includes exhaust openings for discharging the consumed air to the environment of the power tool. A method for protecting a user of a power tool from dust is also provided. The invention is associated with the essential advantage that air flows that exist as a result of the air cooling inside the power tool are exploited in order to blow the dust that accrues during operation of the power tool in a spatial direction “away from the user”. In a particularly preferred configuration, the air blown out can form an air curtain as a dust shield, which protects the user effectively from dust in that the air curtain keeps the dust away from the user and their airways.

Provided is a machine tool hand including a body portion that is mounted so as to be attachable to and detachable from a spindle of a machine tool, and that is provided with a flow path connected to a coolant-liquid supply path formed in the spindle; and two or more hand members that are attached to the body portion such that at least one of the hand members is pivotable about a prescribed axis, and that are capable of gripping an object therebetween by being closed. The flow path is provided with discharge ports via which a coolant liquid supplied from the coolant-liquid supply path is discharged toward surfaces of the hand members that are exposed to an outside, and a pressure of the coolant liquid causes an opening operation or a closing operation of the hand members.

Spindle for carrying out machining assisted by non-ultrasonic axial oscillations, including a tool-bearing shaft, and an exciting portion, for subjecting the shaft to non-ultrasonic axial oscillations, especially during its rotation. The exciting portion including a first exciting stage, having at least one piezoelectric actuator, and a second exciting stage, having at least one piezoelectric actuator, having a non-zero axial overlap with the first exciting stage, the actuators of the two stages being arranged so that their effects add.

A sealing portion on a lower end of a cover portion of a spindle cover has an upper side surface and a lower side surface that are inclined toward an outer circumferential surface of a spindle. A larger-diameter disk and the outer circumferential surface of the spindle define therebetween a second gap that is narrower than a first gap defined between the spindle and the cover portion. The second gap is effective to prevent a processing waste liquid from entering between the spindle and the spindle cover to prevent a solid waste contained in the processing waste liquid from sticking to the spindle. The spindle is thus prevented from becoming less liable to rotate smoothly due to solid waste deposits.

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°.