Provided is a rotor of a brushed motor capable of reducing the occurrence of contamination during press-fitting of a commutator onto a knurling and reducing defect factors due to rotor contamination to improve productivity. In a rotor of a brushed motor having a commutator press-fitted onto a knurling of a shaft, an inclined surface is provided on an inner circumferential side of the commutator, and an angle of the inclined surface is configured to be smaller than an angle of an axial end portion of the knurling. The knurling may be configured to be at a position different from a shaft stepped end surface of the shaft and the knurling may be configured to be positioned axially inward of the commutator from an end surface of the commutator.

The invention relates to a disk blank (18) for producing commutator bars of a disk commutator as well as to a commutator bar and a disk commutator realized as having such commutator bars, said disk blank (18) being realized as a multi-layered body and having a carbon mold body having a continuous first layer and having a contact arrangement which forms a second layer disrupted by transition areas in such a manner that the transition areas do not comprise any contact material.

A rotor of a dynamoelectric machine is provided, the rotor comprising a shaft, an essentially cylindrical armature, an armature coil comprising aluminum coil wires and a drum commutator, which comprises an insulating support body and conductor segments which are attached to said support body and fixed therein by means of armature sections. Said conductor segments each comprise a copper running surface area and a connection area made of aluminum or a metal which can be soldered with aluminum (aluminum-compatible metal) having a soldering tag which greatly projects over the brush running surface. Said coil wires are soldered to the end side to the soldering tag of the respectively associated conductor segments and to be precise, without directly contacting the areas of the running surface.

A rotor of a dynamoelectric machine is provided, the rotor comprising a shaft, an essentially cylindrical armature, an armature coil comprising aluminum coil wires and a drum commutator, which comprises an insulating support body and conductor segments which are attached to said support body and fixed therein by means of armature sections. Said conductor segments each comprise a copper running surface area and a connection area made of aluminum or a metal which can be soldered with aluminum (aluminum-compatible metal) having a soldering tag which greatly projects over the brush running surface. Said coil wires are soldered to the end side to the soldering tag of the respectively associated conductor segments and to be precise, without directly contacting the areas of the running surface.

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.

The invention relates to a disc commutator and a drum commutator for an electric motor having at least two commutator plates, each having a sliding-surface segment for contacting a carbon brush, said sliding-surface segments being electrically separated from one another. In the disc commutator, the electrical separation extends between the sliding-surface segments towards a commutator diameter inclined at an angle In the drum commutator, the electrical separation of the sliding-surface segments is inclined in the longitudinal direction of the drum commutator and forms an angle with a projection of the rotational axis of the drum commutator on the casing surface of the drum commutator.

Commutator of the present invention includes electrically conductive part, resin part, ceramic part, first mixing part and second mixing part. First mixing part contains an electrically conductive material and a ceramic material in mixture. In first mixing part, a content of the electrically conductive material decreases and a content of the ceramic material increases from electrically conductive part toward ceramic part. Second mixing part contains the ceramic material and the resin material in mixture. In second mixing part, a content of the ceramic material decreases and a content of the resin material increases from ceramic part toward resin part.

Commutator of the present invention includes electrically conductive part, resin part, ceramic part, first mixing part and second mixing part. First mixing part contains an electrically conductive material and a ceramic material in mixture. In first mixing part, a content of the electrically conductive material decreases and a content of the ceramic material increases from electrically conductive part toward ceramic part. Second mixing part contains the ceramic material and the resin material in mixture. In second mixing part, a content of the ceramic material decreases and a content of the resin material increases from ceramic part toward resin part.

A commutation apparatus for an electric machine, having brushes with a front face which lies against the peripheral surface of a collector which has a plurality of collector segments separated by gaps, is designed in such a manner that a contact edge which runs obliquely to the gaps is formed on the front face of at least one brush.