Abstract: A starter for cranking an engine has a pinion gear coupled via a helical spline to an output shaft driven by an electric motor. The pinion gear is pushed forward to engage with a ring gear of the engine by restricting rotation of the pinion. A rod member is coupled to one of depressions formed on an outer periphery of an annular member integrally formed with the pinion gear to restrict the rotation of the pinion gear. Rollers are disposed between the neighboring two depressions to reduce abrasive force between the rod member and the outer periphery of the annular member under a situation where the pinion gear is forcibly rotated by the electric motor while its rotation is restricted. The rod member coupled to the depression rolls over the rollers to be coupled to other depressions to allow such a forcible rotation of the pinion gear, thereby alleviating the abrasive force.

Abstract: A rotary electric machine includes a stacked brush, where low-resistance and high-resistance brush layers are disposed at the front and rear end sides in the rotational direction of a commutator, respectively. When the insulation gap between the neighboring segments of a commutator is “a” and the width of the high-resistance brush layer is “b”, “a” and “b” are determined to satisfy a<b and b/a<4 to reduce sparks and improve commutation property. In order to reduce spark generation at the brush front end, especially, when the circumferential width of the segment is “c” and the width of the low-resistance brush layer is “d”, “a” to “d” are determined to satisfy b+d>2×a+c, d>b, a<b and d<a+c.

Abstract: A rotary electric machine includes a plurality of permanent magnet main poles disposed on an inner periphery of a yoke and a plurality of auxiliary poles respectively disposed between neighboring two of the main poles via magnet fixing members and a plurality of magnet fixing members. The magnet-fixing member is comprised of a U-bent elastic metal plate having a pair of circumferentially opposite walls that provides a pole space. The opposite walls are respectively bent inward at edges thereof in circumferentially opposite directions to be opposed to each other. The bent edges have and elastic projections and are separated at the axial ends to form an elastic retaining member. The auxiliary pole is inserted into the auxiliary pole space by opening the elastic retaining member.

Abstract: A lead wire unit of a DC rotary electric machine having a frame and a plurality of brushes is comprised of an outside power supply wire, one or more brush-lead wires, a metal joint and a grommet fixed to the frame. The metal joint has an outside surface to which the outside power supply wire is welded and an inside surface to which said brush lead wire are welded. The grommet has a hollow portion to which the metal joint is force-fitted and a holding portion for holding the outside power supply wire near the metal joint.

Abstract: In an armature, a slot insulation paper provided in a slot of an armature core protrudes from an insulation plate in the axial direction. A part of the slot insulation paper that faces an outer peripheral surface of a coil end is cut out to expose the outer peripheral surface of the coil end. A reinforcing ring is fitted at the axial outside of the armature core to surround the exposed outer peripheral surface of the coil end. Accordingly, the reinforcing ring is disposed close to the armature core in the axial direction. Therefore, a straight portion of the coil end is shortened by an amount of cut of the slot insulation paper, and as a result, the axial length of the armature is shortened.

Abstract: A rotary electric machine includes a stacked brush, where low-resistance and high-resistance brush layers are disposed at the front and rear end sides in the rotational direction of a commutator, respectively. When the insulation gap between the neighboring segments of a commutator is “a” and the width of the high-resistance brush layer is “b”, “a” and “b” are determined to satisfy a<b and b/a<4 to reduce sparks and improve commutation property. In order to reduce spark generation at the brush front end, especially, when the circumferential width of the segment is “c” and the width of the low-resistance brush layer is “d”, “a” to “d” are determined to satisfy b+d>2×a+c, d>b, a<b and d<a+c.

Abstract: One end of a metallic wire having a rectangular cross-section is widened by upsetting the end of the wire in its axial direction. At the same time, a swollen portion is formed at a position where the widened end portion is to be bent from a straight portion of the wire. Then, the widened end portion is bent at the bending position having the swollen portion. Thus, a metallic wire segment having the widened end portion bent at the bending position is manufactured without wasting any part of wire material, while avoiding formation of cracks on the outer surface of the bending position. Plural wire segments thus manufactured are combined to form a rotor winding of a rotational electric machine, forming a commutator surface by the widened end portions at the same time.

Abstract: An armature is constructed by installing a lower layer coil and an upper layer coil in double layers in each slot provided on an armature core. A straight portion of the upper layer coil installed in the slot includes coil end portions at both side ends, which protrude from both axial end surfaces of the armature core in an axial direction. A liquid resin is filled in an inner groove defined among adjacent coil end portions in a peripheral direction, the axial end surface of the armature core and an outer insulating plate. Also, a cylindrical body (non-magnetic material) is mounted on an outer periphery of the coil end portions. Accordingly, brush powder is restricted from entering the inner groove, and a creeping distance for insulation between the armature core, the lower layer coil, and the upper layer coil can be secured.

Abstract: A rotary electric machine includes a plurality of permanent magnet main poles disposed on an inner periphery of a yoke and a plurality of auxiliary poles respectively disposed between neighboring two of the main poles via magnet fixing members and a plurality of magnet fixing members. The magnet-fixing member is comprised of a U-bent elastic metal plate having a pair of circumferentially opposite walls that provides a pole space. The opposite walls are respectively bent inward at edges thereof in circumferentially opposite directions to be opposed to each other. The bent edges have and elastic projections and are separated at the axial ends to form an elastic retaining member. The auxiliary pole is inserted into the auxiliary pole space by opening the elastic retaining member.

Abstract: A method of manufacturing a yoke includes a step of cutting a steel plate into a rectangular sheet having a plurality of first dovetail convexities at one end thereof and a plurality of second dovetail convexities at the other end, a step of rolling the rectangular sheet into a cylinder to fit the first dove tails and the second dove tails to each other and a step of punching border portions of the first dove tails and the second dove tails. The second dovetail convexities are formed to be the same in shape as the first dovetail convexities so that they can fit to the first dovetail convexities. A smooth-faced yoke can be manufacture without using an expensive welder.

Abstract: In a two-layer brush for a commutator, the plane form projected on a commutator surface is nearly similar to the plane form of the segment. A molding die used in brush fabrication has a lower punch which slides obliquely up and down along a sliding groove provided in the lower die, and an upper punch which can slide obliquely up and down in relation to the lower punch. The pressure applying face of the upper punch is formed nearly level, while the pressure receiving face 9a of the lower punch is inclined by a predetermined angle relative to the pressure applying face of the upper punch. It is, therefore, possible to form a first brush material to a predetermined shape, and to apply a uniformly pressure to the second brush powder, to thereby form a second brush material having nearly fixed thickness.

Abstract: A DC motor includes an armature, an armature shaft, a commutator, a plurality of brushes in contact with the commutator, a plurality of brush springs for respectively biasing the brushes against the commutator, and a brush holder unit for holding the pair of brushes. Each of the brush springs comprises a springy spring body disposed at a side of corresponding one of the brushes and a spring arm extending from the spring body to bias the rear end of the corresponding one of the brushes against the commutator, and the spring body has an outer periphery disposed within the axial length of the corresponding one of the brushes.

Abstract: A rotary electric machine includes a frame having a bearing box at a rear center thereof, a stator fixed to the frame, a rotor disposed inside the frame to be rotatable inside stator, a bearing fitted to the bearing box to support a rear portion of a rotor shaft, and a bearing cover fitted to the bearing box. The bearing cover is a rubber-made cup-shaped member having a hollow cylindrical portion, a plurality of ring-shaped projections around the cylindrical portion and a waterproofing bottom.

Abstract: A commutator-integrated armature of a rotary electric machine is comprised of a rotary shaft, an armature core composed of a plurality of laminated sheets, an armature coil composed of a plurality of conductor segments. The conductor segments have in-slot portions respectively inserted into a plurality of slots of the armature core and end portions forming a flat commutator. The armature core has an anchoring portion for anchoring a part of each of the in-slot portions to the armature core more strongly than the rest thereof. The surface of the flat commutator is maintained flat even if the conductor segments repeat thermal expansion and contraction.

Abstract: A planetary gear speed reduction mechanism has a sun gear, an internal gear and a plurality of planetary gears disposed between both gears. Each tooth of the sun gear has a tapered portion formed at a front end thereof such that the tapered portion tapers off in the axial direction. The tapered portion has a pair of symmetrical inclined surfaces whose width is tapered off in the circumferential direction from a tooth surface of each tooth and a tapered surface whose peripheral surface is tapered off in the radial direction from an end of a tooth crest surface. In the process of inserting the sun gear into a space among the planetary gears, the sun gear is inserted thereinto under the guide of the inclined surface by slightly rotating the sun gear.

Abstract: A lead wire unit of a DC rotary electric machine having a frame and a plurality of brushes is comprised of an outside power supply wire, one or more brush-lead wires, a metal joint andagrommet fixedtotheframe. Themetal joint has anoutside surface to which the outside power supply wire is welded and an inside surface to which said brush lead wire are welded. The grommet has a hollow portion to which the metal joint is force-fitted and a holding portion for holding the outside power supply wire near the metal joint.

Abstract: An electromagnetic switch has a solenoid coil, a sleeve and a movable core which slides in the sleeve. A metal thin film is formed on an outer peripheral surface of the movable core by electroplating. The metal thin film is harder than the inner surface of the sleeve, and has high melting point and high smoothness. Accordingly, adhesive wear between the sleeve and the movable core is reduced, and sliding durability under high temperature is improved.

Abstract: A method of manufacturing a field coil for motors that does not require winding of a field coil on a pole core of a stator and that improves the space factor of the field coil. On a part of a conductor, an opening is formed to pass a pole core laid out in a stator therethrough and a spiral slit is formed to pass through the conductor in the thickness direction and connect the outer circumference of the conductor and the opening. An insulation material may be provided in the spiral slit when necessary.

Abstract: In a starter having a motor yoke, a housing and an end frame forming a cylindrical starter frame, a cylindrical thermal insulation cover is fitted around the starter frame through rubber-made elastic rings. The rings are tightly fitted in V-shaped grooves formed circumferentially on fitting faces, one being between the housing and the yoke and the other being between the yoke and the end frame. Each ring is pressed radially inward by a large diameter part of the thermal insulation cover to fill in the V-shaped groove and contact the fitting face. Further, in a motor for the starter, a resilient plate sheet is disposed between a commutator and a brush holder to return a brush passing therethrough to the original position when the brush tends to move during sliding contact with the commutator.

Abstract: An upper coil bar and lower coil bar are disposed in slots of an armature core. The upper coil bars have upper coil-end sections which extend radially from the outer periphery of the armature core and together form a commutator surface with which a brush member is in contact. The upper coil-end sections and coil-end sections of the lower coil bars are retained by a fixing cap fixed between a shaft of the rotary electric machine and the upper coil-end sections, and also by a spacer disposed between the upper coil-end sections and the lower coil-end sections so that the commutator surface can be maintained smooth even under conditions of thermal expansion or high-speed operation.