Denso Corporation

Denso Corpora Tion

Takashi Hirabayashi

Tatsuya Fujita

Tasuku Yamada

Tsutomu Shiga

Masami Niimi

Mitsuhiro Murata

Tadahiro Kurasawa

Akifumi Hosoya

Taro Fukuda

Ken Takehara

In order to facilitate the assembly of the brush assembly and to improve the productivity, the brush device includes a positive side brush subassembly having a positive side brush for feeding a commutator, a positive side brush holder for holding the positive side brush, and a positive side plate to which the positive side brush holder is attached, and a negative side brush subassembly having a negative side brush for feeding the commutator, a negative side brush holder for holding the negative side brush, and a negative side plate to which the negative side brush holder is attached. The positive side brush subassembly and the negative side brush subassembly are combined with each other.

Brush device, electric motor with brush device, and manufacturing method of brush device

A DC motor is provided that can suppress a commutator from wearing. A DC motor including a commutator formed of copper or a copper alloy of 99% or more copper, and a brush pressed against and in contact with the commutator, wherein the brush is composed of a sintered compact including graphite and copper powder, hard compound particles higher in hardness than any of the copper or the copper alloy and the graphite or the copper powder are contained in at least one of the commutator and the brush and are scattered on or near a contact surface of the commutator with the brush at least during use.

DC motor

A motor includes a stator that has pole cores and a stator coil comprised of unit coils each being concentratedly wound around a corresponding one of the pole cores. Each of the unit coils is comprised of first and second sub-coils that are stacked in two layers in a stacking direction. Each of the first and second sub-coils is spirally wound so that coil sides of the sub-coil overlap each other in an overlapping direction perpendicular to the stacking direction. Each of the unit coils also has, at a single place, a connecting portion that connects the first and second sub-coils of the unit coil. The connecting portion is provided in a coil end of the unit coil. For each of the first and second sub-coils of the unit coil, the connecting portion is located at an innermost periphery of the sub-coil in the overlapping direction of the sub-coil.

Motor having concentratedly-wound stator coil

A starter for an internal combustion engine includes a rotating shaft formed with a helical spline on an outer periphery thereof and which rotates by a rotation of a motor, a pinion gear helically splined to the rotating shaft and movable in an axial direction of the rotating shaft along a tooth surface of the helical spline, a lever receiving member disposed opposing an end surface in an axial direction of the pinion gear, moved by receiving an axial pushing force by a pushing member, and causing the pinion gear to engage with a ring gear of the internal combustion engine by a movement thereof, and a buffer member for restricting a movement of the pinion gear in a rotational direction when the pinion gear moves along the teeth surface of the helical spline.

Starter for internal combustion engine

A DC motor is provided for use in a starter that starts an ermine. The DC motor includes a commutator and a brush. The commutator is formed of copper or a copper alloy whose copper percentage content is higher than or equal to 99 mass %. The brush is arranged in sliding contact with a surface of the commutator. Moreover, the brush is formed of a sintered compact that contains graphite, copper and at least one metal sulfide solid lubricant. The percentage content of copper in the sintered compact is 30-70 mass %. The at least one metal sulfide solid lubricant includes tungsten disulfide. The percentage content of tungsten disulfide in the sintered compact is higher than or equal to 6.5 mass %.

DC motor for starter

A starter includes a motor configured with a direct current motor. The direct current motor has a brush and a commutator. The brush is a sintered material formed of graphite and a copper powder. The commutator is formed of either copper or a copper alloy that has a copper content of 99% or more. A surface of is a sliding portion of the commutator which has sliding movement with the brush is provided with a graphite cover-layer that contains graphite as a main component. The graphite cover-layer contains a hard compound which has a Vickers hardness higher than 10 GPa and a metal sulfide solid lubricant.

Starter, and formation of graphite cover layer for commutator surface

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.

DC motor and method of manufacturing the same

A starter includes a coil spring disposed between a pinion gear and a motor and a buffer rubber disposed between the pinion gear and the coil spring. When the pinion gear is subjected to a reactive force from an engine, the buffer rubber absorbs the impact. Before the impact acts on the pinion gear, the coil spring is subjected to a given initial load. When the impact acts on the pinion gear, the coil spring absorbs it transmitted through the buffer rubber. The cover in which the coil spring is stored has a flange which is held from moving to the pinion gear in response to expansion of the coil spring, while it is permitted to move to the motor in response to contraction of the coil spring. This eliminates a risk that mechanical noise occurs when the pinion gear is advanced and then brought into mesh with the engine.

Starter

A first brush holder is assembled to a core-side connection plate by inserting a slit insertion portion into a slit from an outer circumferential side of the core-side connection plate, and a radial outside position of the first brush holder to the core-side connection plate is regulated by both sides in a circumferential direction of a first slit being inserted into a pair of guiding grooves. A radial outside position of the brush holder is regulated by being fixed to a counter-core-side connection plate by press-fitting a convex portion provided on a counter-core-side of the first brush holder into a second slit of a counter-core-side connection plate. A second brush holder is assembled to the counter-core-side connection plate from an outer circumferential side of the counter-core-side connection plate, and a radial outside position is regulated by the core-side connection plate.

A positive connection plate of a DC motor includes a fitting groove to enable assembling a specific brush holder thereto. The specific brush holder includes a convex part that fits in the fitting groove and a stepped surface having a step at a radially outer side of the convex part, and located at the opposite-core side of its armature from a core-side end surface of the convex part. A space existing in an axial stepped area which is located at the core side from the stepped surface and in which the step is formed is a stepped space. A drawing member is drawn from a position which circumferentially overlaps with the specific brush holder to the outside of a motor case, and is disposed so as to overlap with the stepped space in the axial direction.

A brush holder has a core side position regulator engaged with a first connection plate to regulate a relative position. The core side position regulator has a projection part projected toward an armature core in the axial direction, and a fitting groove portion defined on both sides of the projection part in a circumferential direction. The relative position in the circumferential direction is regulated by an engagement between the projection part and a slit of the first connection plate. The relative position in the axial direction is regulated by an engagement between sides of the slit and the fitting groove portion. A width of the projection part in the circumferential direction is larger than a width of a brush in the circumferential direction.

Direct current motor

An engine starting apparatus is equipped with a starter which, when it is required to start an engine, moves a pinion to establish engagement with a ring gear coupled to the engine and energizes an electric motor to produce and transmit torque to the ring gear through the pinion for cranking the engine. When the rate of decrease in current flowing in the electric motor or the rate of rise in voltage appearing at a terminal of the starter or a power supply for the electric motor exceeds a given value after the engine starts being cranked, the engine starting apparatus works as a firing-up determiner to determine that the engine has been fully fired up.

Growing community of inventors

Chita-gun, Japan

Takashi Hirabayashi