Disclosed herein is a brush wear indicator comprising and brush (3) moveable within a holder (2). The brush (3) is urged against a collector surface (10) of a rotor by a spring (4) which is mounted to a bracket (6) supported by the holder (2). A proximity sensor (5) is mounted to either a) the spring (4) or the brush (3), or b) a non-moveable part of the indicator which includes the bracket and configured to determine the distance to a) the non-moveable parts or b) the spring (4) or brush (3), respectively. The proximity sensor (5) in electrical communication with a CPU configured to determine the amount of wear that has occurred to the at least one brush (3) depending on the distance determined by the sensor (5) between the spring (4) or the brush (3) and the non-moveable parts.

A method for producing a metal porous body includes the steps of: performing electrical conduction treatment on a surface of a skeleton of a sheet-like resin porous body having the skeleton with a three-dimensional network structure, to obtain a conductive resin porous body having a conductive layer; performing electroplating treatment on a surface of a skeleton of the conductive resin porous body to obtain a plated resin porous body having a metal plating layer; and performing treatment of removing at least the resin porous body from the plated resin porous body to obtain a metal porous body. In the electroplating treatment, power is supplied to a rotation shaft of a rotating electrode roller while a contact surface of a power supply brush composed of a sintered body is brought into sliding contact with the rotation shaft, with a lubricant, not containing conductive metal powder, interposed therebetween.

A motor including: a frame having an outer diameter of 10 millimeters or less and an inner surface; an annular magnet attached to the inner surface of the frame; a bracket provided at the frame; a columnar brush formed of carbon and having an outer peripheral surface; a commutator contacting the outer peripheral surface of the brush; and an elastic member supporting the brush at the bracket, in which a part of the elastic member is inside the brush.

A universal motor includes a commutator brush with a cavity for sheltering a constant force spring from a wire shunt. In some examples, the cavity can be formed by milling a blind hole into the brush such that an axial centerline of the hole is perpendicular to the brush's length. The cavity is near the back end of the brush, at the end farthest away from the commutator, but is also slightly forward to leave a rear portion of the brush to serve as a barrier between the wire shunt and the spring. The diameter of the cavity is slightly larger than the width of the brush, so the cavity creates a slot in the side of the brush. The slot allows part of the spring to reach out beyond the cavity to where the spring can hook onto a front edge of a stationary sleeve that supports the brush.

A drive including a commutator motor having a motor housing, an end shield secured to the housing, feedthroughs defined in the end shield, brushes mounted in the feedthroughs; and at least one stranded conductor forming a direct electrical and mechanical connection between a brush and the terminal contact arranged outside the motor housing.

Provided is a lightning protection system for a wind turbine, including a connection unit to be placed between a nacelle and at least one blade of the wind turbine for conducting lightning current and/or static energy from the at least one blade to the nacelle, the connection unit including a first end portion with at least one nacelle contacting element, a second end portion with at least one blade contacting element, at least one first support member supporting the at least one nacelle contacting element, at least one second support member supporting the at least one blade contacting element, a base portion located between the first support member and the second support member, and at least one shifting element mechanically connecting the first support member and/or the second support member slidably relative to the base portion for amending a length of the connection unit in an amending direction from the blade to the nacelle.

A brush holding assembly for an excited-rotor electric machine includes a casing including two ducts flanking each other and developing along a direction between first and second ends, at least two brushes each housed capable of sliding in a respective duct and projecting outwardly to the second end and a connecting member arranged to connect with an electric current generation unit associated with said casing at the first end. The assembly also includes presser members associated with the brushes and configured to push the brushes towards the second end to keep them pressed on the respective tracks of a rotating manifold of a rotor and at least two conductive elements developing along the direction, each operatively interposed between a respective brush and the connecting member and configured to deform along the direction in order to follow the movement of the brush imparted by the presser members.

A power tool includes a brush holder with a brush positioned more accurately with respect to a commutator. A grinder as a power tool includes a housing, a stator fixed to the housing, a rotor rotatable relative to the stator and including a commutator and a coil, a brush that comes in contact with the commutator, a brush-holding metal plate having a screw hole and holding the brush, and a screw extending through the screw hole and directly fastened to the housing.

An electric motor is provided including: a stator, an armature rotatably received within the stator and having an armature shaft on which a commutator is mounted, and a brush assembly. The brush assembly defines a first side facing the stator and a second side. The brush assembly includes a brush card mount having openings, brushes in sliding contact with the commutator, and thermally-conductive brush holders that support the brushes. Each brush holder includes a base piece disposed between the first side of the brush assembly and the stator, and a main piece including a brush-holder portion and two side flat portions. The brush-holder portion is axially received through a brush card mount opening from the first side of the brush assembly and protrude over the second side to house a brush. The two side flat portions are axially sandwiched between the base piece and the brush card mount.

The invention relates mainly to an assembly comprising a brush cage and a spiral spring (36), the spiral spring (36) comprising an axis (Y), a wound part (37) wound about the axis (Y) and an arm (39) extending from one end of the wound part (37), the brush cage comprising at least one lateral wall provided with an opening for the passage of the arm (39) through the lateral wall so that one end of the arm (39) can press against at least part of an end face of a brush, wherein the arm (39) comprises a first portion (391) of which the width (L5) measured along the axis (Y) is different from the width (L6) of the wound part (37) measured along the axis (Y) of the spiral spring (36).