A torque transfer device is provided to transfer torque from a torque tool to a torque limiter device, the torque transfer device comprising a torque limiter connection member adapted for connection to the torque limiter device; a first joint; a second joint; and a tool connection member adapted for connection to the torque tool, wherein the first joint and the second joint are configured to lock responsive to activation of the torque tool to transfer a reaction torque generated by the torque tool to the torque limiter device, and wherein the first joint and the second joint are configured to unlock responsive to deactivation of the torque tool to enable rotation between the torque tool and the torque limiter device along a first axis and a second axis different from the first axis.

[Object] To provide a shaft bearing capable of reducing rotational resistance of a drive shaft by use of a ball bearing instead of a bush (slide bearing).

[Constitution] A shaft bearing includes a bearing, a cylindrical holder, and an elastic ring. The holder is formed by combining two members divided parallel to an axial direction, and is assembled in a state where an outer peripheral part of the bearing is stored in an inner groove formed on an inner peripheral surface of the holder in a peripheral direction, and the elastic ring is stored in an outer groove formed on an outer peripheral surface of the holder in the peripheral direction.

Provided is a handpiece in which a predetermined section of a rotational power transmission shaft includes a plurality of flexible rods. The single rotational power transmission shaft is able to change the direction of the rotation center axis of a rotational power source in order to overcome problems, such as rotational power loss, noise, fine vibration, reduced durability, or an increase in volume, caused by a complicated gear connecting structure of a rotational power transmission shaft for changing the direction of the rotation center axis of the rotational power transmission shaft of a related-art rotational power source.

A crankshaft (1) for a crankcase scavenged two stroke piston engine (2) is disclosed. The crankshaft (1) is configured to rotate around a rotation axis (ax) during operation. The crankshaft (1) comprises a crankpin (3) configured to move in a crank plane (cp) during operation, and a first and a second counterweight (5, 7) arranged on either side (S1, S2) of the crank plane (cp). The first counterweight (5) has a first outer radius (r1) measured from the rotation axis (ax) and the second counterweight (7) has a second outer radius (r2) measured from the rotation axis (ax). The first outer radius (r1) is smaller than the second outer radius (r2). The present disclosure further relates to a power unit (10), a crankcase scavenged two stroke piston engine (2), and a hand-held power tool (20).

A bearing adapter for a disk-shaped accessory tool which has two sides. The bearing adapter includes a bearing unit configured to reduce a bearing recess of the accessory tool. The bearing unit is configured to adjoin the accessory tool and to enclose a portion of the accessory tool on the two sides when the bearing unit is mounted on the accessory tool.

In a management system which manages user equipment installed in a prescribed space managed by a user, the user equipment including a plurality of motion guidance devices each including a track member, a moving member, and a plurality of displacement sensors which detect displacements of the moving member in a prescribed number of displacement directions in the moving member, on the basis of lifespan-related information corresponding to each of the plurality of motion guidance devices, a lifespan exhaustion ratio of each motion guidance device is calculated and, on the basis of the calculated lifespan exhaustion ratio, replacement object devices to be replaced within a prescribed period which constitute a part of or all of the plurality of motion guidance devices are determined. In addition, a user is notified of a replacement timing at which all of the determined replacement object devices in the user equipment are to be replaced.

A roller bearing for at least one set of roller bodies, which are disposed in an annular manner, the roller bearing having at least one track element with a track, on which the roller bodies are provided for rolling. The track comprises a track base having a circular circumferential line. The track element comprises, on each axial side of the track base, a shoulder or a rim for the roller bodies, each shoulder or rim having a circular circumferential line. The track element is formed such that, as viewed perpendicular to the planes defined by the circumferential lines, all center points of the three circumferential lines are different from each other.

A telescopic drive shaft in a protective tube of a handheld work apparatus has one end connected to a rotational drive and the other end thereof to a driven tool. The drive shaft includes a rigid shaft segment and a connecting section. The rigid shaft segment has a hollow shaft end portion and an engagement length (E) of the connecting section engages therein. The engagement length (E) and the length of the hollow shaft end portion mutually overlap to form a joining section. The hollow shaft end portion is deformed for connecting the connecting section to the rigid shaft segment. The material of the hollow shaft end portion is compressed over its entire periphery and deformed so that the material of the hollow shaft end portion is radially displaced and is pressed in a rotative manner onto the engagement length (E) to produce a balanced, loadable connection.

In a management system which manages user equipment installed in a prescribed space managed by a user, the user equipment including a plurality of motion guidance devices each including a track member, a moving member, and a plurality of displacement sensors which detect displacements of the moving member in a prescribed number of displacement directions in the moving member, on the basis of lifespan-related information corresponding to each of the plurality of motion guidance devices, a lifespan exhaustion ratio of each motion guidance device is calculated and, on the basis of the calculated lifespan exhaustion ratio, replacement object devices to be replaced within a prescribed period which constitute a part of or all of the plurality of motion guidance devices are determined. In addition, a user is notified of a replacement timing at which all of the determined replacement object devices in the user equipment are to be replaced.

A power tool includes a housing having a motor housing portion and a front casing coupled to the motor housing portion. The power tool also includes an electric motor positioned within the motor housing portion, a drive assembly having an output shaft to which a tool element for performing work on a workpiece is attachable, and a powdered metal bushing disposed within the front casing that rotatably supports the output shaft.