JP2007104800A - Rotating electric machine for vehicles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating electric machine for vehicles wherein noise produced at a nail-shaped magnetic pole is reduced. <P>SOLUTION: An alternating-current generator 1 as a rotating electric machine for vehicles includes: a rotor 2 having a pair of pole cores 22, 23 having multiple nail-shaped magnetic poles that alternately form a north pole and a south pole along the direction of rotation, and are bent in the axial direction, a field coil 21, and a rotating shaft 24; and a stator 3 having a stator core 31 disposed opposite to the rotor 2, and stator winding 32 wound on the stator core 31. The rotor 2 includes covering members 200, 210 that cover recesses formed from the shoulders of the multiple nail-shaped magnetic poles to the end faces of the pole cores 22, 23. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicular rotating electrical machine mounted on a passenger car, a truck, or the like.

  In recent years, the space for mounting AC generators for vehicles has been reduced as the engine room has become more and more narrow due to the need for slant nose to reduce vehicle running resistance and the need to secure cabin space. . In addition, the engine speed has been lowered to improve fuel efficiency, and the speed of the vehicle alternator has also decreased. However, on the other hand, there is a demand for an increase in electrical loads such as safety control devices, and an increase in power generation capacity is demanded more and more. That is, it is required to provide a small-sized and high-output vehicle alternator at low cost.

  In addition, engine noise has been decreasing in recent years due to social demands for reducing noise outside the vehicle and the aim of improving product quality by improving the quietness of the passenger compartment. Auxiliaries that rotate at relatively high speeds, especially AC generators for vehicles. The wind noise has become easy to hear.

Most of the wind noise of the vehicle alternator is wind noise caused by the rotation of the rotor, and pitch noise generated from the shoulders of the claw-shaped magnetic poles occupies a large proportion. On the other hand, the noise between the adjacent claw-shaped magnetic poles is reduced over the entire circumference of the rotor for the purpose of suppressing the unpleasant noise generated by the uneven shape due to the gap between the adjacent claw-shaped magnetic poles. A vehicle alternator covered with a member is known (for example, see Patent Documents 1 and 2).
Japanese Patent No. 2903574 (page 2-4, FIG. 1-7) Japanese Patent Laid-Open No. 11-341762 (page 3-4, FIG. 1-9)

  By the way, in the vehicle alternator disclosed in Patent Document 1 and Patent Document 2, since the noise suppression member only covers the shoulder portion and the outer peripheral portion of the claw-shaped magnetic pole, it rotates from the shoulder portion of the claw-shaped magnetic pole. There was a problem that noise generated by the uneven shape of the axial end face toward the axis could not be prevented.

  The present invention was created in view of the above points, and an object of the present invention is to provide a vehicular rotating electrical machine capable of reducing noise generated in a claw-shaped magnetic pole.

  In order to solve the above-described problems, a rotating electrical machine for a vehicle according to the present invention includes a pair of pole cores and field coils having a plurality of claw-shaped magnetic poles bent in the axial direction alternately forming NS magnetic poles along the rotational direction. And a rotor having a rotating shaft, and a stator having a stator core disposed opposite to the rotor and a stator winding wound around the stator core. And a covering member that covers the recess formed from the shoulders of the plurality of claw-shaped magnetic poles to the end face of the pole core. By covering with a covering member from the shoulder part of the claw-shaped magnetic pole of the rotor to the end face in the axial direction, the unevenness formed by the recesses in these regions can be eliminated. Occurrence can be prevented.

  The rotor described above includes a cooling fan fixed to the axial end surface of the pole core, and the covering member is preferably sandwiched between the pole core and the cooling fan. By disposing the covering member in this way, when the cooling fan is fixed to the pole core, the covering member can also be fixed at the same time. Therefore, the manufacturing becomes easy and the manufacturing cost can be reduced.

  The covering member described above is preferably formed of an annular nonmagnetic metal. Thereby, it becomes possible to form a covering member having sufficient mechanical strength and heat resistance.

  Moreover, it is desirable that the covering member described above covers the shoulder portion of the claw-shaped magnetic pole that is outside the region facing the stator core and that faces the stator winding. Since the claw-shaped magnetic poles and the stator iron core are disposed to face each other with a slight gap, if a covering member is disposed between them, the gap is expanded and performance is deteriorated. Further, since the claw-shaped magnetic pole of this portion is covered with the stator core on the outer peripheral side, the noise generated by the uneven shape of this portion is small. On the other hand, since the space between the stator winding and the shoulder portion of the claw-shaped magnetic pole facing the stator winding is large, it is easy to arrange the covering member in this space. Further, since the noise generated by the uneven shape of the shoulder is large, the effect of noise reduction becomes remarkable by covering the shoulder.

  The covering member described above preferably has a protrusion or tongue at a position corresponding to the recess. Thereby, positioning of a covering member becomes easy. Also, since the mounting position is accurately determined, by removing a part of the covering member that is shielded when other parts such as a cooling fan are mounted, the area of the covering member is reduced and the amount of material used is reduced. Therefore, the material cost can be reduced.

  Hereinafter, an automotive alternator as a vehicular rotating electrical machine according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing the overall structure of an automotive alternator according to an embodiment. As shown in FIG. 1, the vehicle alternator 1 of this embodiment includes a rotor 2, a stator 3, a front side housing 4, a rear side housing 5, a brush device 6, a rectifier 7, a voltage regulator 8, It includes a pulley 9 and the like.

  The rotor 2 includes a pair of pole cores 22 and 23 having a plurality of claw-shaped magnetic poles that are bent in the axial direction to alternately form NS magnetic poles along the rotation direction, and an insulated copper wire that is cylindrical and concentric. A field coil 21 wound around and a rotating shaft 24. Further, on the end face of the pole core 22 on the front side (pulley 9 side), a cooling fan 25 that mixes the axial flow type or the axial flow type and the centrifugal type in order to discharge the cooling air sucked from the front side in the axial direction and the radial direction. Are fixed by welding or the like (for example, projection welding). A covering member 200 is sandwiched between the pole core 22 and the cooling fan 25. Similarly, a centrifugal cooling fan 26 for discharging the cooling air sucked from the rear side in the radial direction is attached and fixed to the end face of the pole core 23 on the rear side by welding or the like. A covering member 210 is sandwiched between the pole core 23 and the cooling fan 26. Details of the covering members 200 and 210 will be described later.

  Slip rings 27 and 28 electrically connected to both ends of the field coil 21 are formed on the rear side of the rotating shaft 24, and the brushes 61 and 62 in the brush device 6 are respectively connected to the slip rings 27 and 28. By assembling in the pressed state, an exciting current flows from the rectifier 7 to the field coil 21.

  In the stator 3, three-phase stator windings 32 are wound at a predetermined interval in a plurality of slots formed in a stator core 31 disposed to face the rotor 2. The rectifier 7 is for rectifying the three-phase alternating current that is the output voltage of the three-phase stator winding 32 of the stator 3 to obtain a direct current output, and is a positive-side heat radiating plate fixed at a predetermined interval. And a negative-side heat radiating plate and a plurality of rectifying elements attached to the respective heat radiating plates by soldering or the like.

  The front-side housing 4 and the rear-side housing 5 accommodate the rotor 2 and the stator 3 described above, and the rotor 2 is supported so as to be rotatable around the rotation shaft 24. The stator 3 is disposed outside the pole cores 22 and 23 via a predetermined gap. The stator 3 is fixed by tightening bolts 34 to four support portions 420 provided at equal intervals along the rotation direction of the rotor 2.

  The voltage regulator 8 is for adjusting the output voltage of the vehicular AC generator 1 by controlling the excitation current that flows through the field coil 21, and the output voltage that varies depending on the electric load and the amount of power generation. Is kept almost constant. The pulley 9 is for transmitting the rotation of an engine (not shown) to the rotor 2 in the vehicular AC generator 1, and has a nut 91 at one end of the rotating shaft 24 (on the side opposite to the slip ring 27 and the like). It is fixed by tightening. A rear cover 92 that protects the brush device 6, the rectifying device 7, and the voltage regulator 8 is attached.

  In the vehicle alternator 1 having the above-described structure, the rotor 2 rotates in a predetermined direction when rotation from the engine is transmitted to the pulley 9 via a belt or the like. At this time, by applying an excitation voltage to the field coil 21, the claw portions of the pole cores 22 and 23 are excited, and a three-phase AC voltage can be generated in the stator winding 32. A predetermined direct current is taken out from the terminal.

  Further, since the cooling fan 25 attached to the end face of one pole core 22 rotates with the rotation of the rotor 2 described above, the cooling is performed via the suction port 440 of the front side housing 4 provided on the pulley 9 side. Wind is sucked into the vehicle alternator 1, the field coil 21 is cooled by the axial component of the cooling wind, and the coil end in front of the stator winding 32 is cooled by the radial component. . The cooling air is then discharged from the discharge port 450 of the front housing 4.

  Similarly, the cooling fan 26 attached to the end face of the other pole core 23 also rotates with the rotation of the rotor 2 described above, so that the cooling air sucked through the suction port of the rear cover 92 is supplied to the rectifier 7. Alternatively, after the voltage regulator 8 is cooled, it is guided to the cooling fan 26 through the suction port 540 of the rear side housing 5, and this cooling air is discharged in the radial direction so that the coil end behind the stator winding 32 is To be cooled. The cooling air is then discharged from a discharge port (not shown) of the rear housing 5.

  Next, the details of the covering members 200 and 210 provided in the rotor 2 will be described. FIG. 2 is a perspective view of the rotor 2. As described above, the covering member 200 is sandwiched between the pole core 22 on the front side and the cooling fan 25. The covering member 200 covers the entire recess formed from the shoulders of the plurality of claw-shaped magnetic poles of the pole core 22 to the axial end face of the pole core 22. FIG. 3 is a perspective view of the covering member 200. As shown in FIG. 3, the covering member 200 is formed in an annular shape, and is formed of, for example, a nonmagnetic metal. Although a schematic shape is shown in FIG. 3, a through hole is actually formed corresponding to the welding position of the cooling fan 25. As shown in FIG. 1, the covering member 200 has a shape that completely covers the shoulders of the claw-shaped magnetic poles facing the stator winding 32 except in the region facing the stator core 31. .

  Similarly, a covering member 210 is sandwiched between the pole core 23 on the rear side and the cooling fan 26. The covering member 210 covers the entire recess formed from the shoulders of the plurality of claw-shaped magnetic poles of the pole core 23 to the axial end surface of the pole core 23. The covering member 210 is formed in an annular shape, and is formed of, for example, a nonmagnetic metal. As shown in FIG. 1, the covering member 210 has a shape that completely covers the shoulders of the claw-shaped magnetic poles facing the stator winding 32 except for the region facing the stator core 31. .

  As described above, in the rotor 2 provided in the vehicle alternator 1 of the present embodiment, the covering members 200 and 210 completely cover the claw-shaped magnetic poles of the pole cores 22 and 23 from the shoulder portions to the axial end faces. Since the unevenness formed by the recesses in these regions can be eliminated, generation of pitch noise (noise) due to these unevenness shapes can be prevented.

  Further, when the cooling members 25 and 26 are fixed to the pole cores 22 and 23 by sandwiching the covering members 200 and 210 by the pole cores 22 and 23 and the cooling fans 25 and 26, the covering members 200 and 210 are also fixed simultaneously. Therefore, manufacturing is facilitated and manufacturing costs can be reduced. Further, by forming the covering members 200 and 210 with an annular non-magnetic metal, it becomes possible to form a covering member having sufficient mechanical strength and heat resistance.

  By the way, since the claw-shaped magnetic poles of the pole cores 22 and 23 and the stator core 31 are arranged to face each other with a slight gap, if the covering members 200 and 210 are arranged between these, the gap is expanded and the performance is deteriorated. Will be invited. Further, since the claw-shaped magnetic pole of this part is covered with the stator core 31 on the outer peripheral side, the noise generated by the uneven shape of this part is small. On the other hand, since the space between the stator winding 32 and the shoulder of the claw-shaped magnetic pole facing the stator winding 32 is large, it is easy to arrange the covering members 200 and 210 in this space. Further, since the noise generated by the uneven shape of the shoulder is large, the effect of noise reduction becomes significant by covering the entire shoulder.

  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. For example, in the above-described embodiment, the covering members 200 and 210 are formed of a nonmagnetic metal, but may be formed of a resin that is a magnetic metal or a material other than a metal.

  In addition, concave portions are formed between the claw-shaped magnetic poles adjacent in the circumferential direction from the shoulder portions of the pole cores 22 and 23 to the axial end surface, and the basic shape of the covering members 200 and 210 covering these concave portions has been described. The covering members 200 and 210 may have protrusions 200a as shown in FIG. 4 or tongues 200b as shown in FIG. 5 at positions corresponding to these recesses. Thereby, the positioning of the covering members 200 and 210 is facilitated. The covering members 200 and 210 having such a complicated shape are desirably formed of a resin material. In addition, since the attachment position is accurately determined, a part of the covering members 200 and 210 that are shielded when other components such as the cooling fans 25 and 26 are attached may be removed. In the most extreme case, as shown in FIG. 6, only the region 200 c exposed from the cooling fan 26 may be left and the portion corresponding to the other region 200 d may be removed. Thereby, the area of the covering members 200 and 210 can be reduced, the amount of material used can be reduced, and the material cost can be reduced.

It is sectional drawing which shows the whole structure of the alternating current generator for vehicles of one Embodiment. It is a perspective view of a rotor. It is a perspective view of a covering member. It is a perspective view of the covering member in other embodiments. It is a perspective view of the covering member in other embodiments. It is a perspective view of the covering member in other embodiments.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle alternator 2 Rotor 3 Stator 4 Front side housing 5 Rear side housing 6 Brush device 7 Rectifier 8 Voltage regulator 9 Pulley 21 Field coil 22, 23 Pole core 24 Rotating shaft 25, 26 Cooling fan 200, 210 Cover member

Claims (5)

A pair of pole cores having a plurality of claw-shaped magnetic poles bent in the axial direction alternately forming NS magnetic poles along the rotation direction, a rotor having a field coil and a rotation shaft, and opposed to the rotor In a rotating electrical machine for a vehicle comprising a stator having a stator core and a stator having a stator winding wound around the stator core,
The rotor includes a covering member that covers a recess formed from a shoulder portion of the plurality of claw-shaped magnetic poles to an end surface of the pole core. In claim 1,
The rotor includes a cooling fan fixed to an end surface in the axial direction of the pole core,
The vehicular rotating electrical machine, wherein the covering member is sandwiched between the pole core and the cooling fan. In claim 1 or 2,
The vehicular rotating electrical machine, wherein the covering member is formed of an annular nonmagnetic metal. In any one of Claims 1-3,
The rotating electrical machine for a vehicle according to claim 1, wherein the covering member covers a shoulder portion of the claw-shaped magnetic pole facing the stator winding outside the region facing the stator core. In any one of Claims 1-4,
The rotating electrical machine for vehicles, wherein the covering member has a protrusion or a tongue at a position corresponding to the recess.

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