Disclosed herein is a wind turbine rotor which includes a plurality of blades and a hub root, wherein at least one blade is provided with at least one electrostatic noise grounding system. The electrostatic noise grounding system includes an insulated rod having a first end and a second end, a conductive core passing through the insulated rod, a first conductive element connected to the conductive core at the first end of the insulated rod, and a second conductive element competed to the conductive core at the second end of the insulated rod. The electrostatic noise grounding system is secured to a portion of the rotor (e.g., blade bearing housing or blade bearing housing bolted connection) such that the first conductive element is in direct physical contact with at least a portion of the surface of at least one blade and the second conductive element is in direct physical contact with at least a portion of the surface of the hub root.

Disclosed herein is a wind turbine rotor which includes a plurality of blades and a hub root, wherein at least one blade is provided with at least one electrostatic noise grounding system. The electrostatic noise grounding system includes an insulated rod having a first end and a second end, a conductive core passing through the insulated rod, a first conductive element connected to the conductive core at the first end of the insulated rod, and a second conductive element competed to the conductive core at the second end of the insulated rod. The electrostatic noise grounding system is secured to a portion of the rotor (e.g., blade bearing housing or blade bearing housing bolted connection) such that the first conductive element is in direct physical contact with at least a portion of the surface of at least one blade and the second conductive element is in direct physical contact with at least a portion of the surface of the hub root.

An electrical machine with a brush commutator arrangement (1) is proposed. Brushes (3) and a commutator (5) are adapted and arranged such that, upon operating the electrical machine (1), the brush (3) and the commutator (5) are displaced relative to each other in a lateral displacement direction (7) and a contact surface (9) of the brush (3) mechanically contacts a contact surface (11) of the commutator (5) along an overlapping area (13) thereby generating an electrical contact. Accordingly, an electric current is transmitted between brush (3) and commutator (5) through the overlapping area (13). An orthogonal electrical conductivity of the brush (3) and/or the commutator (5) in a direction (25) orthogonal to a respective contact surface (9, 11) locally varies along the lateral displacement direction (7). An orthogonal electrical conductivity distribution in the brush (3) and/or the commutator (5) is adapted such that, even when operating the electrical machine at maximum allowable power, for at least 90% of all spatial configurations during displacing the brush (3) and the commutator (5) relative to each other, an electrical current density through the overlapping area (13) does not exceed 130% of a rated maximal average electrical current density through the brush commutator arrangement (1). Due to the specific variation of orthogonal electrical conductivity within the brush (3) or commutator (5), sparking and resulting wear in the proposed brush commutator arrangement (1) may be reduced.

An electrical machine with a brush commutator arrangement (1) is proposed. Brushes (3) and a commutator (5) are adapted and arranged such that, upon operating the electrical machine (1), the brush (3) and the commutator (5) are displaced relative to each other in a lateral displacement direction (7) and a contact surface (9) of the brush (3) mechanically contacts a contact surface (11) of the commutator (5) along an overlapping area (13) thereby generating an electrical contact. Accordingly, an electric current is transmitted between brush (3) and commutator (5) through the overlapping area (13). An orthogonal electrical conductivity of the brush (3) and/or the commutator (5) in a direction (25) orthogonal to a respective contact surface (9, 11) locally varies along the lateral displacement direction (7). An orthogonal electrical conductivity distribution in the brush (3) and/or the commutator (5) is adapted such that, even when operating the electrical machine at maximum allowable power, for at least 90% of all spatial configurations during displacing the brush (3) and the commutator (5) relative to each other, an electrical current density through the overlapping area (13) does not exceed 130% of a rated maximal average electrical current density through the brush commutator arrangement (1). Due to the specific variation of orthogonal electrical conductivity within the brush (3) or commutator (5), sparking and resulting wear in the proposed brush commutator arrangement (1) may be reduced.

A brush used to contact with a commutator, includes a brush body which includes two opposite axial end faces and a protruding portion projecting from the brush body toward the commutator. The protruding portion includes a first surface, a second surface and at least two teeth. The first surface and the second surface are respectively adjacent to the two axial end faces. Angles formed between the first surface and the second surface and corresponding adjacent axial end faces are obtuse. The teeth is located between the first surface and the second surface, and extends generally along a circumferential direction of the commutator. The ratio of a total width of the at least two teeth in an axial direction of the brush to an axial height of the brush body is in the range of 0.25-0.75. An electric motor including the brush is also provided.

A brush used to contact with a commutator, includes a brush body which includes two opposite axial end faces and a protruding portion projecting from the brush body toward the commutator. The protruding portion includes a first surface, a second surface and at least two teeth. The first surface and the second surface are respectively adjacent to the two axial end faces. Angles formed between the first surface and the second surface and corresponding adjacent axial end faces are obtuse. The teeth is located between the first surface and the second surface, and extends generally along a circumferential direction of the commutator. The ratio of a total width of the at least two teeth in an axial direction of the brush to an axial height of the brush body is in the range of 0.25-0.75. An electric motor including the brush is also provided.

A method produces a brush for a commutator motor, in particularly for a motor vehicle fan, for electrically contacting a connected contact lead to a commutator via a spring-loaded contact with a commutator. Accordingly, a brush material, particularly carbon dust, is poured into a cuboid matrix and compressed by a plunger in a contact direction for forming the brush.

A method produces a brush for a commutator motor, in particularly for a motor vehicle fan, for electrically contacting a connected contact lead to a commutator via a spring-loaded contact with a commutator. Accordingly, a brush material, particularly carbon dust, is poured into a cuboid matrix and compressed by a plunger in a contact direction for forming the brush.

There is provided a contact type power feeding apparatus in which, even if a brush Br disposed in a space between the axis body and the cylinder body that are disposed concentric with each other wears out as a result of sliding, contact can be surely secured between the brush and the axis body as well as the cylinder body, thereby efficiently causing electric current to flow between the two. A brush Br has first brush pieces each having an inner wall surface to make surface-contact with an outer peripheral surface of the axis body; and second brush pieces each having an outer wall surface to make a surface-contact with an inner peripheral surface of the cylinder body. The brush is constituted by alternately arranging, in the circumferential direction, the first brush pieces and the second brush pieces in a state of keeping them in surface-contact with each other. The side wall surfaces of the first brush pieces and the second brush pieces are respectively formed into a tapered shape which is inclined relative to the radial direction. Coil springs are disposed between the second brush pieces that are adjacent to each other, in order to give a biasing force in a direction to move the second brush pieces away from each other.

A method for making contact wires for sliprings comprising the steps of: coating and/or plating a wire with a first metal of the group of nickel, chrome or a combination thereof; coating and/or plating the wire with a second metal of the group of gold, silver, or a combination thereof; delivering laser radiation and generating an interference pattern of the laser radiation to the surface of the wire; heating the surface selectively as defined by the interference pattern, modifying of the crystal structure and/or providing protrusions and/or recesses due to melting and/or evaporation of the surface material.