JP4609190B2 - Rotating electric machine for vehicles - Google Patents

Description

  The present invention relates to a vehicular rotating electrical machine mounted on a vehicle such as a passenger car or a truck and driven by an internal combustion engine.

  In recent years, an AC generator for a vehicle is required to be small in size and high in output due to an increase in an electric load of a safety control device or the like and an overcrowded engine room. In addition, high efficiency is also demanded from the demand for improved fuel economy.

In order to meet these requirements, a multi-phase winding is formed by joining a plurality of segment conductors with a rectangular cross section to reduce the internal resistance of the AC generator for vehicles and the copper loss, which is the main loss. An automotive alternator has been proposed (see, for example, Patent Document 1). In this vehicle AC generator, a segment conductor having a rectangular cross section is inserted into a rectangular slot from the axial direction of the stator core, and then the segment conductor is bent and connected in the circumferential direction to prevent interference between the windings. Realizes high space and low resistance stators.
Japanese Unexamined Patent Publication No. 2000-14068 (page 3-6, FIG. 1-5)

  However, the above-described conventional vehicle alternator has the following problems. When bending the segment conductors in the circumferential direction or joining the segment conductors, force acts on the segment conductors in the circumferential direction, but the segment conductors that are bent linearly during the bending process are joined in an annular shape A part of the force applied in the circumferential direction of the segment conductor is converted into a force in the inner diameter direction due to the distortion generated by doing so. This internal force is generated for all segment conductors, and the resultant force acts on the innermost segment conductor. Therefore, high stress is generated between the innermost segment conductor and the teeth of the stator core. Resulting in.

  In particular, in order to prevent magnetic flux leakage between adjacent tooth tips, the planar shape of the teeth tip has an edge portion close to a right angle, so that the stress in the inner diameter direction described above is concentrated on this edge portion, and this edge portion. In the case of forming the stator core by stacking the laminated plates, burrs are easily generated when each laminated plate is manufactured by press molding, and the insulating paper in contact with the edge portion is easily broken. In addition, when a high stress is generated between the edge portion and the segment conductor, the segment conductor film is likely to be cracked or peeled off even if the insulating paper is not torn. Since an AC generator for a vehicle is mounted on a vehicle, there is a possibility that water, chloride, or a conductive material such as a car shampoo may enter from the outside. Will lead to deterioration. Due to these factors, insulation failure is likely to occur between the segment conductor and the stator core, and there is a problem that reliability with respect to the use environment is lowered.

  Although measures such as reducing the gap between the segment conductor and the slot and making it difficult for the segment conductor to move are conceivable, this makes it difficult to insert the segment conductor and increases manufacturing time and costs. New problems arise.

  The present invention has been created in view of the above points, and an object of the present invention is to improve the reliability with respect to the use environment, and to facilitate the manufacture and the cost reduction of the vehicle. Is to provide.

  In order to solve the above-described problems, a rotating electrical machine for a vehicle according to the present invention includes a rotor, a stator core disposed on the outer diameter side of the rotor, and an armature winding provided in the stator core. The stator core has a thick portion having a predetermined thickness from the outer diameter side toward the inner diameter direction, a teeth portion protruding from the thick thickness portion to the inner peripheral side, and an innermost portion of the teeth portion. The armature winding is housed in a slot as a space surrounded by the back thick portion, the tooth portion, and the tooth tip portion, and the armature winding has a tooth tip portion extending in the circumferential direction from the circumferential portion. The end portions of the plurality of segment conductors are joined to each other, and the plurality of segment conductors are arranged in a line inside the slot. Further, the above-described slot has a circumferential width that is gradually narrowed from the outer diameter side toward the inner diameter side, and the segment conductors that are accommodated in the slot and disposed on the innermost diameter side are arranged on both sides along the circumferential direction. The surface abuts against the side surface in the circumferential direction of the slot, so that it is locked at a predetermined position in the slot with a predetermined radial gap between the front end of the tooth. As a result, even when an external force is applied in the circumferential direction when the portion of the segment conductor protruding from the stator core is bent, and the force in the inner diameter direction acts on the segment conductor, the segment conductor and teeth tips arranged on the innermost diameter side Since there is no direct contact with the part, it is possible to prevent damage to the insulation film formed on the surface of the segment conductor and damage to the insulation member disposed between the segment conductor and the stator core, and a good insulation state It is possible to improve the reliability of the usage environment by securing the system. In addition, when inserting the segment conductor into each slot of the stator core, if it is moved to a predetermined position on the inner diameter side after being inserted on the outer diameter side, a sufficient gap is secured around the segment conductor at the time of insertion. Therefore, the manufacturing can be facilitated and the cost can be reduced without impairing the insertability.

  In addition, it is desirable that the segment conductors arranged on the innermost diameter side described above have a circumferential width that is narrower from the outer diameter side to the inner diameter side of the stator core. As a result, the segment conductor on the innermost diameter side is opposed to the circumferential side surface of the slot, and the segment conductor is locked with a radial gap between the segment conductor and the tip of the tooth. Becomes easy.

  Further, it is desirable that the segment conductor disposed on the innermost diameter side described above has a side surface formed of a plane having a rectangular cross section and opposed to the circumferential side surface of the slot. As a result, the contact surface where the segment conductor and the side surface of the slot come into contact with each other can be widened, so that stress concentration generated on the surface of the segment conductor or the insulating member can be reduced. It is possible to further improve the reliability by further reducing the damage.

  Further, it is desirable that each of the plurality of segment conductors accommodated in the slot in a state of being arranged in a line in the radial direction described above has substantially the same cross-sectional shape. Thereby, a plurality of segment conductors can be formed from the same material (for example, a continuous line), and the component cost can be reduced.

  In addition, the segment conductor described above has a U shape having a turn portion, and it is desirable to form an armature winding by joining the opposite end portions of the two segment conductors to each other. Thereby, the number of parts of a segment conductor and the number of joining locations can be reduced, and the cost can be reduced by facilitating manufacturing.

  Hereinafter, an automotive alternator according to an embodiment to which a rotating electrical machine for a vehicle of the present invention is applied will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of an AC generator for a vehicle according to an embodiment. As shown in FIG. 1, an automotive alternator 1 according to this embodiment includes a rotor 2 that works as a field, a stator 3 that works as an armature, and a housing that supports the rotor 2 and the stator 3. 4, a rectifier 5 connected to the stator 3 for converting AC power into DC, and a voltage regulator 11 for controlling the power generation amount by increasing or decreasing the field current amount of the rotor 2.

  The rotor 2 rotates integrally with the shaft 6 and includes a Landel pole core 21, cooling fans 22 and 23, a field coil 24, slip rings 25 and 26, and the like. The stator 3 includes a stator core 31, an armature winding 32, and a sheet-like insulating member 34 that electrically insulates the stator core 31 and the armature winding 32. The stator 3 is disposed opposite to the outer peripheral side of the rotor 2 and is supported by a pair of housings 4. The stator core 31 is formed in an annular shape by superposing thin steel sheet sheets.

  FIG. 2 is a partial cross-sectional view of the stator 3. FIG. 3 is a perspective view of a segment conductor constituting the armature winding 32. FIG. 4 is a partial perspective view showing one coil end shape of the stator 3. As shown in FIG. 2, the stator core 31 includes a back thick portion 311 having a predetermined thickness along the radial direction from the outer diameter side, a teeth portion 312 protruding from the back thick portion 311 to the inner diameter side, and a teeth portion. And a tooth tip 313 extending in the circumferential direction from the innermost peripheral portion of 312. A slot 314 is formed by a space (pre-space) surrounded by the thick portion 311, the tooth portion 312, and the tooth tip portion 313. A tooth edge portion 315 having a substantially right angle is formed at the end of the opposing surface of the two tooth tip portions 313 adjacent to each other in the circumferential direction corresponding to the same slot 314.

  An armature winding 32 is accommodated in the slot 314. The armature winding 32 is formed by joining the end portions of the segment conductor 33 shown in FIG. In the present embodiment, the four segment conductors 33 constituting the armature winding 32 are accommodated in the slots 314 in a state of being arranged in a row in the radial direction. These segment conductors 33 have a rectangular cross section at least in a portion accommodated in the slot 314, and have a side surface formed of a plane facing the circumferential side surface of the slot 314.

  As shown in FIG. 3, the segment conductor 33 is formed in advance from the portion 33h positioned in the slot 314, and only one tip portion 33i is formed in advance, and the tip portion 33j opposite to the tip portion 33i is inserted into the slot 314. Then, the opposite end portion 33j is bent in the P direction shown in FIG. 3, that is, in the circumferential direction of the annular stator core 31. Thereafter, as shown in FIG. 4, the tip portions 33j are joined to each other by welding, brazing or the like (the tip portion 33i is joined in the same manner), so that the armature winding 32 includes each phase of the multiphase winding. Is formed.

  An insulating member 34 is interposed between the segment conductor 33 and the stator core 31 so as to surround the four segment conductors 33, and electrical insulation between them is ensured. In addition, an insulating film is formed around each segment conductor, and electrical insulation between adjacent segment conductors 33 is achieved.

  Each slot 314 formed in the stator core 31 of the present embodiment has a circumferential width that is gradually narrowed from the outer diameter side toward the inner diameter side. In the example shown in FIG. 2, the segment conductor 33a accommodated in the slot 314 and disposed on the innermost diameter side gradually decreases in the circumferential width from the outer diameter side to the inner diameter side of the stator core 31. The both side surfaces along the circumferential direction are in contact with the circumferential side surface of the slot 314. Thus, the segment conductor 33a is locked at a predetermined position in the slot 314 with a predetermined radial gap 316 between the segment tip 33a and the tooth tip 313.

  As described above, since the segment conductor 33 is locked in a state where the radial gap 316 is formed between the segment conductor 33 disposed on the innermost diameter side in the slot 314 and the tooth tip 313, the segment conductor 33 is locked. Even when an external force is applied in the circumferential direction when the portion of the conductor 33 protruding from the stator core 31 is bent, a force in the inner diameter direction acts on the segment conductor 33, and the segment conductor 33 and the tooth edge portion arranged on the innermost diameter side There is no direct contact with 315. As a result, damage to the insulating coating on the surface of the segment conductor 33 and damage to the insulating member 34 caused by part of the segment conductor 33 being pressed against the tooth edge portion 315 can be prevented, and use by ensuring a good insulation state Improves environmental reliability. Further, when the segment conductor 33 is inserted into each slot 314 of the stator core 31, if the segment conductor 33 is moved to a predetermined position on the inner diameter side after being inserted on the outer diameter side, a sufficient area around the segment conductor 33 at the time of insertion is obtained. Since the gap can be secured, it is possible to realize easy manufacturing and cost reduction without impairing the insertability.

  In addition, the circumferential width of at least the segment conductor 33 arranged on the innermost diameter side becomes narrower from the outer diameter side of the stator core 31 toward the inner diameter side, so that the circumferential side surface of the segment conductor 33 is slotted. The segment conductor 33 can be easily locked with the radial gap 316 provided between the segment conductor 33 and the tooth tip 313 so as to face the circumferential side surface of 314.

  Further, the segment conductor 33 arranged at least on the innermost diameter side has a rectangular cross section and has a side surface formed of a plane facing the circumferential side surface of the slot 314. As a result, the contact surface where the segment conductor 33 and the side surface of the slot 314 come into contact with each other can be widened, so that the stress concentration generated on the surface of the segment conductor 33 or the insulating member 34 can be reduced. It is possible to further improve the reliability by further reducing the damage to the insulating coating and the insulating member 34.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. In the embodiment described above, the four segment conductors 33 accommodated in the slots 314 have a wider circumferential width than the segment conductors 33 positioned from the inner diameter side to the outer diameter side. As shown, the cross-sectional shapes of the four segment conductors 33 may all be the same trapezoidal shape. As a result, the types of segment conductors 33 can be reduced, and each segment conductor 33 can be formed from the same material (for example, a continuous line), so that the component cost can be reduced.

  In addition, as shown in FIG. 6, only the innermost segment conductor 33a may have a rectangular cross section, which may function as a stopper, and the other segment conductors 332 may have other shapes, for example, a substantially circular cross section. Also in this case, it is the same that the radial gap 316 can be secured between the segment conductor 33 arranged on the innermost peripheral side and the tooth tip 313, and it is possible to improve reliability and reduce cost. Become.

  Further, as shown in FIG. 7, the cross section may not be trapezoidal as long as it is a segment conductor having a plane opposite to the inner wall surface (circumferential side surface) of the slot 314 as a side surface. For example, as shown in FIG. 7, a segment conductor 333 having a polygonal cross section (for example, an octagon) may be used.

  Further, as shown in FIG. 8, a segment conductor 334 having a U-shaped turn portion 33C may be used. Since the number of the segment conductors 334 and the number of joints can be reduced with respect to the linear segment conductor 33 shown in FIG. 3, the cost can be reduced by facilitating manufacturing.

  In the embodiment described above, the segment conductor 33 having a rectangular cross section is used in advance. However, a more versatile circular cross section copper wire or the like is used, and the cross section of only the portion arranged in the slot 314 is rectangular. It may be processed and used. At this time, the cost of the segment conductor itself can be reduced by using a more versatile wire.

It is sectional drawing of the alternating current generator for vehicles of one Embodiment. It is a fragmentary sectional view of a stator. It is a perspective view of the segment conductor which comprises an armature winding. It is a fragmentary perspective view which shows one coil end shape of a stator. It is a fragmentary sectional view of the stator which shows other examples of a segment conductor. It is a fragmentary sectional view of the stator which shows other examples of a segment conductor. It is a fragmentary sectional view of the stator which shows other examples of a segment conductor. It is a perspective view which shows the other example of a segment conductor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC generator for vehicles 2 Rotor 3 Stator 31 Stator iron core 311 Back thick part 312 Teeth part 313 Teeth tip part 314 Slot 315 Teeth edge part 316 Radial direction gap 32 Armature winding 33 Segment conductor 34 Insulating member 4 Housing

Claims (3)

A rotor, and a stator having a stator core disposed on the outer diameter side of the rotor and an armature winding mounted on the stator core, the stator core from the outer diameter side. A thick portion having a predetermined thickness toward the inner diameter direction, a tooth portion protruding from the thick portion toward the inner peripheral side, and a tooth tip portion extending in the circumferential direction from the innermost peripheral portion of the tooth portion are provided. The armature winding is housed in a slot as a space surrounded by the back thick portion, the tooth portion, and the tip end portion of the tooth, and the armature winding joins end portions of a plurality of segment conductors. In the rotating electrical machine for a vehicle formed by the plurality of segment conductors arranged in a row inside the slot,
The slot is set to have a gradually narrower circumferential width from the outer diameter side toward the inner diameter side,
The segment conductor housed in the slot and disposed on the innermost diameter side has both end surfaces in the circumferential direction abutting against the circumferential side surface of the slot, so that the tip of the tooth is positioned at a predetermined position in the slot. It is locked in a state through a predetermined radial gap without directly contacting the part,
The segment conductor arranged on the innermost diameter side has a circumferential width set narrower from the outer diameter side to the inner diameter side of the stator core, and has a rectangular cross section, and the circumferential side surface of the slot A rotating electrical machine for a vehicle having a side surface composed of a flat surface facing the surface. In claim 1,
Each of the plurality of segment conductors accommodated in the slot in a state of being arranged in a line in the radial direction has substantially the same cross-sectional shape. In claim 1 or 2,
The segment conductor has a U shape having a turn part,
The vehicular rotating electrical machine characterized in that the armature winding is formed by joining ends of the two segment conductors opposite to each other on the turn side.

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