Abstract: A motor includes a frame in the shape of a bottomed cylinder, a stator housed in the frame, a rotor, an end plate for closing an opening of the frame, and bearings rotatably supporting a rotary shaft of the rotor. The frame has, on its bottom, a bearing holder at the center and ribs extending like rays from the bearing holder radially outward and protruding to the inside of the frame. Each rib has a radially outer end reaching a circumferential wall of the frame.

Abstract: A motor includes a frame in the shape of a bottomed cylinder, a stator housed in the frame, a rotor, an end plate for closing an opening of the frame, and bearings rotatably supporting a rotary shaft of the rotor. The frame has, on its bottom, a bearing holder at the center and ribs extending like rays from the bearing holder radially outward and protruding to the inside of the frame. Each rib has a radially outer end reaching a circumferential wall of the frame.

Abstract: This brush holder assembly includes: a brush holder formed in a disk shape by molding of insulating resin, and including a pair of box fixing sections each including a groove formed from an outer peripheral side toward inside: and brush box assemblies each having a brush box which houses a brush therein, each of the brush box assemblies being disposed in the box fixing section. Each of the brush box assemblies is formed of box-like metal, and has a plurality of mounting legs. Additionally, each of the box fixing sections of the brush holder has a plurality of mounting holes. In this brush holder assembly, these mounting legs are inserted into the respective mounting holes, and the brush box assembly is fixed. Furthermore, in the brush holder assembly of the present invention, the brush holder assemblies face the brush holder through gaps. Additionally, a commutator motor of the present invention includes the above brush holder assembly.

Abstract: A motor which includes: inner ring having upper end surface, outer ring, and balls between inner ring and outer ring. Pressurizing spring, into which rotary shaft is inserted, is located between core and bearing, and provides bias forces in the axial direction of rotary shaft. Outer ring is pressed to fit into bearing holding part. Inner ring is fitted onto rotary shaft with gap therebetween. Upper end surface of inner ring is in contact with pressurizing spring. Pressurizing spring applies the bias forces of different strengths onto a surface in which upper end surface contacts with pressurizing spring, along a circumferential direction with the axial direction as a center.

Abstract: This brush holder assembly includes: a brush holder formed in a disk shape by molding of insulating resin, and including a pair of box fixing sections each including a groove formed from an outer peripheral side toward inside: and brush box assemblies each having a brush box which houses a brush therein, each of the brush box assemblies being disposed in the box fixing section. Each of the brush box assemblies is formed of box-like metal, and has a plurality of mounting legs. Additionally, each of the box fixing sections of the brush holder has a plurality of mounting holes. In this brush holder assembly, these mounting legs are inserted into the respective mounting holes, and the brush box assembly is fixed. Furthermore, in the brush holder assembly of the present invention, the brush holder assemblies face the brush holder through gaps. Additionally, a commutator motor of the present invention includes the above brush holder assembly.

Abstract: A motor which includes: inner ring having upper end surface, outer ring, and balls between inner ring and outer ring. Pressurizing spring, into which rotary shaft is inserted, is located between core and bearing, and provides bias forces in the axial direction of rotary shaft. Outer ring is pressed to fit into bearing holding part. Inner ring is fitted onto rotary shaft with gap therebetween. Upper end surface of inner ring is in contact with pressurizing spring. Pressurizing spring applies the bias forces of different strengths onto a surface in which upper end surface contacts with pressurizing spring, along a circumferential direction with the axial direction as a center.

Abstract: A dc motor includes a stator having multiple field magnet poles, and an armature having an armature core, armature coils, and a commutator, and brushes brought into contact with the commutator. The armature coils include concentrated winding coil units wound on respective teeth, and connecting wire units that electrically connect each of the concentrated winding coil units together. A segment group of the commutator includes a first segment and a second segment placed adjacent to each other, to which the concentrated winding coil units are connected, the segment group also includes a third segment disposed next to the adjacent placement, and only the connecting wire unit is connected to the third segment. The connecting wire units include connecting wire units that pass through slots and connect each of the concentrated winding coil units together.

Abstract: A commutator motor is configured such that an armature includes an armature core having teeth and slots, an armature coil, and a commutator having segments. The armature coil includes coil units in which windings are wound on the teeth, and jumper wire units for interconnecting between the coil units. Segment group includes first and second segments to which the coil units are connected, and a third segment to which only the jumper wire unit is connected. The first and second segments are disposed adjacent to each other, and the third segment is disposed next to the adjacent arrangement. The configuration includes the jumper wire unit that is wired from the third segment such that each of one part of the wire unit running to one side and the other part of the wire unit running to the other side is wired to pass through the same slot to interconnect between the coil units.

Abstract: A commutator motor is configured such that an armature includes an armature core having teeth and slots, an armature coil, and a commutator having segments. The armature coil includes coil units in which windings are wound on the teeth, and jumper wire units for interconnecting between the coil units. Segment group includes first and second segments to which the coil units are connected, and a third segment to which only the jumper wire unit is connected. The first and second segments are disposed adjacent to each other, and the third segment is disposed next to the adjacent arrangement. The configuration includes the jumper wire unit that is wired from the third segment such that each of one part of the wire unit running to one side and the other part of the wire unit running to the other side is wired to pass through the same slot to interconnect between the coil units.

Abstract: A dc motor includes a stator having multiple field magnet poles, and an armature having an armature core, armature coils, and a commutator, and brushes brought into contact with the commutator. The armature coils include concentrated winding coil units wound on respective teeth, and connecting wire units that electrically connect each of the concentrated winding coil units together. A segment group of the commutator includes a first segment and a second segment placed adjacently to each other, to which the concentrated winding coil units are connected, the segment group also includes a third segment disposed next to the adjacent placement, and only the connecting wire unit is connected to the third segment. The connecting wire units include connecting wire units that pass through slots and connect each of the concentrated winding coil units together.

Abstract: An arc length in contact with a commutator of two brushes in a rotational direction of a motor is defined as not more than 5% of an outer rim length or circumference of the commutator, i.e., not more than ?A/2O, where A is an outside diameter of the commutator. A number of shorted segments of the commutator, which short is caused by the brush, can be minimized so that reduction in output of the motor can be prevented. As a result, the motor employed in a car product or an electric tool can be downsized and made lighter.

Abstract: The present invention provides for its object a compact electric motor effective to provide a high reliability against the leakage of grease from a bearing on one side adjacent the output shaft or the ingress of oil from a counterpart machine. The compact electric motor 1 has a wall 14 having a predetermined gap around an output shaft 3 between a commutator 7 and a bearing 6, wherefore in the event of leakage of grease from the bearing 6 on an output side or ingress of oil from the counterpart machine, it is possible to prevent deposition on the commutator 3 and the brush 5 and, hence, to avoid an abnormal wear of the brush 5 and reduction in performance of the compact electric motor 1.

Abstract: The present invention provides for its object a compact electric motor effective to provide a high reliability against the leakage of grease from a bearing on one side adjacent the output shaft or the ingress of oil from a counterpart machine.

Abstract: An arc length—contacting with a commutator—of two brushes in a rotational direction of a motor is defined as not more than 5% of an outer rim length of the commutator, i.e., not more than &pgr;×/20, where A is an outside diameter of the commutator. A number of shorted segments of the commutator—the short is caused by the brush—is minimized, so that reduction in output of the motor can be prevented. As a result, the motor employed in a car product or an electric tool can be downsized and light-weighted.

Abstract: A DC motor has a projection which projects from the bottom surface of the brush-holder plate. The projection extends to outside in the axial direction of the motor. A terminal conductor is inserted into a perforated hole formed in the projection. One end of the terminal conductor is exposed to the outside of the motor from the tip of the projection, while another end of the terminal conductor is connected electrically to the brush. The projection functions as the built in type electrical connector to the motor, which when coupled to a power supply, powers the DC motor.