A brush motor includes: a rotor core provided in a rotor; s teeth provided in the rotor core; s concentrated-winding coils with electric wires being respectively wound around the teeth; a commutator provided on the rotor in a relatively non-rotatable manner; c commutator pieces provided in the commutator and connected to the coils; p pairs of magnet magnetic poles provided on a stator and arranged to face the teeth; and a brush that is brought into sliding contact with the commutator pieces to supply a current to the coils, in which 0.5<p/s<1 and s<c.

A rotor includes coils that are formed by winding wires around bobbins of a core, terminals which are arranged on the bobbins and to which end portions of the wires are hooked, and a commutator arranged at an end portion of the core on a side where the terminals are arranged. The terminals and commutator segments of the commutator are electrically connected via metal pieces extending from the commutator segments and via a wiring board.

A rotor includes coils that are formed by winding wires around bobbins of a core, terminals which are arranged on the bobbins and to which end portions of the wires are hooked, and a commutator arranged at an end portion of the core on a side where the terminals are arranged. The terminals and commutator segments of the commutator are electrically connected via metal pieces extending from the commutator segments and via a wiring board.

A DC motor includes a cylindrical yoke constituting a magnetic path, pole cores fixed to an inner periphery of the yoke so as to be arranged at even intervals along a circumferential direction of the yoke, and a field conductor that generates a magnetic field to magnetize the pole cores when supplied with a current. The field conductor includes inter-core conductors each of which extends in an axial direction of the yoke so as to be disposed between circumferentially adjacent pole cores. Each of the inter-core conductors is formed by integrating a first conductor part that generates a magnetic field to be applied to one of the circumferentially adjacent pole cores and a second conductor part that generates a magnetic field to be applied to the other of the circumferentially adjacent pole cores.

A DC motor includes a cylindrical yoke constituting a magnetic path, pole cores fixed to an inner periphery of the yoke so as to be arranged at even intervals along a circumferential direction of the yoke, and a field conductor that generates a magnetic field to magnetize the pole cores when supplied with a current. The field conductor includes inter-core conductors each of which extends in an axial direction of the yoke so as to be disposed between circumferentially adjacent pole cores. Each of the inter-core conductors is formed by integrating a first conductor part that generates a magnetic field to be applied to one of the circumferentially adjacent pole cores and a second conductor part that generates a magnetic field to be applied to the other of the circumferentially adjacent pole cores.

The invention relates to a commutator motor (10), particularly as part of a windscreen-wiper motor (100), having at least four magnet elements (11 to 14) which are arranged on a reference-circle diameter around an axis of rotation of an armature shaft (2) with polarity that alternates in the circumferential direction, and having an armature (15) with armature slots (N1 to N18) and armature teeth (Z1 to Z18), wherein winding wires (20) having a multiplicity of windings (27, 28) in each case for constructing coils (C1 to C9) are arranged in the armature slots (N1 to N18), wherein a start (21) and an end (22) of a winding wire (20) is electrically conductively connected to a commutator hook (H1 to H18) in each case, wherein a winding wire (20) has two winding-wire sections (25, 26), which are arranged in the region of different magnet elements (11 to 14) in such a manner that a first winding-wire section (25) with a first number of windings (27) in a first winding direction is assigned to a first magnet element (11 to 14) and is located in two armature slots (N1 to N18), and that a second winding-wire section (26) with a second number of windings (28) in a second winding direction, opposite to the first winding direction, is assigned to a second magnet element (11 to 14) and is located in two armature slots (N1 to N18), and wherein the two magnet elements (11 to 14) have different polarities.

The invention relates to a commutator motor (10), particularly as part of a windscreen-wiper motor (100), having at least four magnet elements (11 to 14) which are arranged on a reference-circle diameter around an axis of rotation of an armature shaft (2) with polarity that alternates in the circumferential direction, and having an armature (15) with armature slots (N1 to N18) and armature teeth (Z1 to Z18), wherein winding wires (20) having a multiplicity of windings (27, 28) in each case for constructing coils (C1 to C9) are arranged in the armature slots (N1 to N18), wherein a start (21) and an end (22) of a winding wire (20) is electrically conductively connected to a commutator hook (H1 to H18) in each case, wherein a winding wire (20) has two winding-wire sections (25, 26), which are arranged in the region of different magnet elements (11 to 14) in such a manner that a first winding-wire section (25) with a first number of windings (27) in a first winding direction is assigned to a first magnet element (11 to 14) and is located in two armature slots (N1 to N18), and that a second winding-wire section (26) with a second number of windings (28) in a second winding direction, opposite to the first winding direction, is assigned to a second magnet element (11 to 14) and is located in two armature slots (N1 to N18), and wherein the two magnet elements (11 to 14) have different polarities.

In a 4-pole, 6-slot, 18-segment electric motor, one forward winding coil (91) and two reverse winding coils (92, 93) are wound on each tooth (12). When the forward winding coils are formed of coils corresponding to a U phase, a V phase, and a W phase and the reverse winding coils are formed of coils corresponding to a U phase, a V phase, and a W phase, the coils, which correspond to a U phase, a W phase, a W phase, a V phase, a U phase, a U phase, a W phase, a V phase, and a V phase, are electrically connected in this order between the adjacent segments. When the number of turns of the coils (91) corresponding to a U phase, a V phase, and a W phase is denoted by T1, the number of turns of the coils (92), which correspond to a U phase, a V phase, and a W phase and first come into sliding contact with a brush, is denoted by T2, and the number of turns of the coils (93), which correspond to a U phase, a V phase, and a W phase and later come into sliding contact with the brush, is denoted by T3, T2>T1>T3 is satisfied.

In a 4-pole, 6-slot, 18-segment electric motor, one forward winding coil (91) and two reverse winding coils (92, 93) are wound on each tooth (12). When the forward winding coils are formed of coils corresponding to a U phase, a V phase, and a W phase and the reverse winding coils are formed of coils corresponding to a U phase, a V phase, and a W phase, the coils, which correspond to a U phase, a W phase, a W phase, a V phase, a U phase, a U phase, a W phase, a V phase, and a V phase, are electrically connected in this order between the adjacent segments. When the number of turns of the coils (91) corresponding to a U phase, a V phase, and a W phase is denoted by T1, the number of turns of the coils (92), which correspond to a U phase, a V phase, and a W phase and first come into sliding contact with a brush, is denoted by T2, and the number of turns of the coils (93), which correspond to a U phase, a V phase, and a W phase and later come into sliding contact with the brush, is denoted by T3, T2>T1>T3 is satisfied.

A power tool includes a motor, a first power source access circuit, a first drive circuit, a second power source access circuit and a second drive circuit. The motor includes a rotor, a stator, a plurality of first-type windings and a plurality of second-type windings. The rotor is configured to rotate about a central axis. The stator includes a ring-shaped yoke portion, and a plurality of teeth. The plurality of first-type windings are configured to be wound around part of the plurality of teeth and the plurality of second-type windings are configured to be wound around other part of the plurality of teeth. The first power source access circuit is configured to access a first power source with a first voltage. The first drive circuit includes a plurality of first-type electronic switches connected between the plurality of first-type windings and the first power source access circuit. The second power source access circuit is configured to access a second power source with a second voltage. The second drive circuit includes a plurality of second-type electronic switches connected between the plurality of second-type windings and the second power source access circuit. The plurality of first-type windings and the plurality of second-type windings are spaced in a circumferential direction of the central axis.