JP2010063250A - Rotating electric machine for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating electric machine for vehicle which can control accumulation of abrasion powder of a brush in a brush holder by causing a flow of air in the brush holder. <P>SOLUTION: An AC generator for vehicle 100 is provided with a rotor 4 which includes a rotating shaft 44 having a pair of slip rings 47 and 48 connected electrically with a field winding 41 and a cooling fan 46 fixed to the axial end face on the slip ring side, a brush device 6 having a pair of brushes 61 and 62 which slide on the slip rings 47 and 48, a brush holder 200 in which sections 211 and 212 for containing the pair of brushes 61 and 62 are formed, and a cover member 250 which covers the slip rings 47 and 48 along with the brush holder 200, a portion 71 to be detected which is arranged at one end of the rotating shaft 44, and a detection section 72 which detects the rotational position of the portion 71 to be detected. A cooling fan 73 is provided between the portion 71 to be detected and the slip rings 47 and 48. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

2. Description of the Related Art Conventionally, there is known a vehicular rotating electrical machine in which a periphery of a slip ring is covered with a covering member and a position detection device fixed to one end of a rotating shaft is disposed outside the covering member through an opening provided in the covering member. (For example, refer to Patent Document 1). This position detection device is sensitive to the magnet holder fixed to the penetrating part of the rotating shaft, the magnet held by the magnet holder, and the magnetic flux emitted from the magnet so as to be close to the facing member and face the covering member. And a magnetically sensitive element that outputs a signal corresponding to this, and a labyrinth structure is formed between the covering member and the magnet holder. This structure makes it difficult for brush wear powder generated during rotation to scatter.
JP 2007-97236 A (page 4-10, FIG. 1-3)

  By the way, since the structure disclosed in Patent Document 1 employs a labyrinth structure in order to prevent scattering of brush wear powder, the flow of air into the brush holder is restricted and the air volume is reduced. There is a problem that the ink is not sufficiently discharged and accumulates in the brush holder. Therefore, brush wear powder may be present on the sliding surfaces of the brush and slip ring, causing abnormal wear of the brush and slip ring. Also, the brush wear powder mixes with water such as seawater and rainwater, so that the brush wear powder that has become solid is interposed between the brush holder and the brush, and the brush adheres to the brush holder and presses against the appropriate slip ring. May not be performed, and there is a risk of poor contact between the brush and the slip ring.

  The present invention was created in view of the above points, and an object of the present invention is for a vehicle capable of suppressing the accumulation of brush wear powder in the brush holder by causing an air flow in the brush holder. It is to provide a rotating electrical machine.

  In order to solve the above-described problems, a rotating electrical machine for a vehicle according to the present invention includes a rotary shaft having a pair of slip rings electrically connected to a field winding and a first fixed to an axial end surface on the slip ring side. A brush device comprising: a rotor including one cooling fan; a pair of brushes slidably in contact with the slip ring; a brush holder in which a storage portion for storing the pair of brushes is formed; and a cover member that covers the slip ring together with the brush holder And a rotational position detected portion disposed at one end of the rotational shaft, and a rotational position detecting portion that detects the rotational position of the rotational position detected portion, and between the rotational position detected portion and the slip ring. A second cooling fan is included.

  By diffusing the air in or around the brush holder by the second cooling fan, the flow of air in the brush holder is promoted, and accumulation of brush wear powder in the brush holder can be suppressed. Further, since the first cooling fan is provided on the axial end surface of the rotor on the slip ring side, the diffused brush wear powder can be effectively discharged, and the brush and slip ring associated with the accumulation of the brush wear powder can be discharged. Abnormal wear and poor contact between them can be prevented.

  In addition, it is desirable that the second cooling fan described above is integrally formed with the rotational position detected portion. Thereby, in addition to the effect of suppressing the accumulation of brush wear powder, the rotational position detected part itself can be efficiently cooled. Further, the cost can be reduced by reducing the number of parts.

  Moreover, it is desirable that the second cooling fan described above is formed as a separate member from the rotational position detected portion. Thereby, while being able to use the material suitable for the 2nd cooling fan, the shape of a rotation position detected part can be simplified.

  The second cooling fan described above is preferably formed on the outer periphery of the rotational position detected portion. As a result, the axial length of the rotational position detected portion can be shortened, and the size of the vehicular rotating electrical machine can be reduced.

  The second cooling fan described above is preferably made of a metal material. Thereby, the cooling property of a rotation position detected part can be improved.

  The second cooling fan described above is preferably formed of a resin material containing metal or ceramics. This makes it possible to reduce the weight of the entire second cooling fan and the rotational position detection unit to suppress vibrations, and to prevent the position detection accuracy from being lowered due to the addition of the second cooling fan.

  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 diagram illustrating an overall configuration of a vehicle AC generator according to an embodiment. 1 includes a front frame 1, a rear frame 2, a stator 3, a rotor 4, a control device 5, a brush device 6, a rotation position sensor 7, a rear cover 8, a pulley 9, and the like. It is configured to include.

  Both the front side frame 1 and the rear side frame 2 have a bowl shape, and are fixed to each other by a plurality of bolts in a state in which the openings 3 face each other and the stator 3 is sandwiched therebetween. A cylindrical bearing box 11 is formed integrally with the front frame 1, and an iron bearing box 21 is attached to the rear frame 2. The stator 3 includes a stator core 31 and a stator winding 32.

  The rotor 4 includes a field winding 41, pole cores 42 and 43, a rotating shaft 44, and the like, and is rotatably held by a pair of bearings 13 and 14 housed in bearing boxes 11 and 21. Cooling fans 45 and 46 are attached to the axial end surfaces of the pole cores 42 and 43. A pulley 9 is coupled to the front end of the rotating shaft 44 by a nut 10 and is rotated by a vehicle engine (not shown). Further, a pair of slip rings 47 and 48 connected to both ends of the field winding 41 are provided at the rear end of the rotating shaft 44 positioned outside the rear frame 2. The cooling fan 46 fixed to the end surface in the axial direction of the pole core 43 on the slip ring 47, 47 side corresponds to the first cooling fan.

  The rotational position sensor 7 detects the rotational position of the rotor 4, is arranged at one end of the rotating shaft 44 and rotates with the rotor 4 as a disk-shaped detected part (rotational position detected part) 71, A detection unit (rotation position detection unit) 72 that detects the rotational position of the detected unit 71 and a cooling fan 73 provided between the detected unit 71 and the rear slip ring 48 are configured. The cooling fan 73 corresponds to the second cooling fan.

  So-called electrical components such as the control device 5 and the brush device 6 are fixed to the outer axial end surface of the rear frame 2 by fixing means such as bolts. The control device 5 rectifies the three-phase AC voltage that is the output voltage of the stator winding 32 and converts it into a DC output voltage, and controls the direction and magnitude of the energization of the excitation current flowing in the field winding 41. By doing so, the output voltage of the vehicle alternator 100 is controlled. The brush device 6 is for passing an exciting current from the control device 5 to the field winding 41 of the rotor 4 and presses against each of the slip rings 47 and 48 formed on the rotating shaft 44 of the rotor 4. Brushes 61 and 62 are provided. These electrical components are covered with a rear cover 8.

  FIG. 2 is a view of the vehicular AC generator 100 as viewed from the rear side, and shows a state in which the brush device 6 is exposed by removing the rear cover 8, the control device 5, and the detection portion 72 of the rotational position sensor 7. . The stator winding 32 includes two sets of three-phase windings 32A and 32B, each phase coil X, Y, Z of one three-phase winding 32A and each phase coil U of the other three-phase winding 32B, Each end of V and W extends to the rear side through a through hole provided in the rear frame 2. These end portions are connected to the control device 5.

  Next, the detailed structure of the brush apparatus 6 and the to-be-detected part 71 is demonstrated. FIG. 3 is a cross-sectional view of the brush device 6 and the rotational position sensor 7. The brush device 6 includes a brush holder 200, brushes 61 and 62, and a cover member 250.

  The brush holder 200 has a box shape, and has a rectangular parallelepiped-shaped storage portions 211 and 212 that store two brushes 61 and 62 on the positive electrode side and negative electrode side, and flexible brushes 61 and 62, respectively. A pair of terminals 221 and 222 that are electrically connected to a pigtail 63 serving as a lead portion having a characteristic and project outside are provided. The terminals 221 and 222 are insert-molded in a brush holder 200 made of insulating resin.

  Further, the cover member 250 is disposed on the radially outer side with respect to the slip rings 47 and 48 and on one end (end portion on the slip ring 47 or 48 side) of the rotating shaft 44, and together with the brush holder 200, the slip ring 47, 48 is covered. Further, the cover member 250 has an opening 262 at a position corresponding to one end of the rotation shaft 44.

  The brushes 61 and 62 are metal graphite containing copper powder in natural graphite and using a phenol resin or the like as a binder. For example, it is manufactured by the manufacturing process shown in FIG. That is, powder processing (step 100) for mixing raw material (natural graphite) and binder (phenol resin), mixing of copper powder (step 101), arrangement of pigtail 63 (step 102), molding (step 103), firing The brushes 61 and 62 are manufactured through each step (Step 104). The brushes 61 and 62 have the same shape, and the same shape is disposed with the pigtails 63 facing each other, and is housed in the housing portions 211 and 212 with the spring 64 interposed. The brushes 61 and 62 are pressed toward the slip rings 47 and 48 by the spring 64 and are in sliding contact within the storage portions 211 and 212.

  The detected portion 71 is fixed to one end (end portion on the slip ring 47, 48 side) of the rotating shaft 44 together with the cooling fan 73 by, for example, screwing or press fitting. The detection unit 72 is fixed to a part of the control device 5 and is disposed to face the detected unit 71, and detects the position in the rotation direction of the region near the outer periphery of the disc-shaped detected unit 71. . Various methods can be considered as specific detection methods. For example, a magnetic body is arranged in the vicinity of the outer periphery of the detected part 71, and the rotational position of the magnetic body is detected by a detection coil provided in the detecting part 72, or a magnet is arranged in the vicinity of the outer periphery of the detected part 71, The case where the rotation position of this magnet is detected with the Hall element provided in the detection part 72 etc. can be considered. A method other than the above, for example, an optical detection method such as an optical sensor may be used.

  5 is a cross-sectional view taken along line VV in FIG. For example, as shown in FIGS. 3 and 5, the detected portion 71 includes a permanent magnet 71 a having NS magnetic poles magnetized every 90 ° along the circumferential direction, and a holder 71 b that holds the permanent magnet 71 a. The detection unit 72 includes two Hall elements 72a and 72b arranged at positions near the outer periphery of the permanent magnet 71a and separated from each other by 90 °. Based on the outputs of these two Hall elements 72a and 72b, the rotational position of the permanent magnet 71a, that is, the rotational position of the rotor 4 to which the permanent magnet 71a is fixed via the holder 71b can be detected.

  FIG. 6 is a perspective view of the cooling fan 73 attached to the detection unit 72. As shown in FIGS. 3 and 6, the cooling fan 73 has two blades, is attached around the rotation axis of the detected part 71, and rotates together with the rotation axis of the detected part 71. The cooling fan 73 is made of a metal material or a resin material mixed with metal or ceramics. When formed of a metal material, the cooling performance of the detected part 71 can be improved. Further, when formed of a resin material in which metal or ceramics is blended, the entire detected portion 71 can be reduced in weight and vibration can be suppressed as compared with the case of forming with a metal material, and a cooling fan 73 is added. As a result, it is possible to prevent the position detection accuracy from being lowered. The number of blades of the cooling fan 73 is not limited to two and may be between three or more.

  The detection unit 72 and the cover member 250 form a maze structure for preventing intrusion of water and other foreign matters from the top. On the other hand, since air has a smaller mass than water and other foreign matters, it reaches the vicinity of the detected portion 71 through the maze structure formed by the detecting portion 72 and the cover member 250, and passes through the opening 262. It is guided to the vicinity of the slip rings 47 and 48. Even if water or other foreign matter reaches the vicinity of the detected portion 71 through the maze structure, it is discharged in the ground direction through a gap between the detecting portions 72 provided in the ground direction.

  The detected portion 71 and the insulating portion 73 of the rotational position sensor 7 described above are attached to one end of the rotating shaft 44 after the brush device 6 is assembled, that is, with the periphery of the slip rings 47 and 48 covered with the cover member 250. Mounting is fixed.

  In the present embodiment, the cover member 250 and the detection unit 72 form a maze structure in a direction along the radial direction of the rotation shaft 44. Specifically, as shown in FIG. 3, a labyrinth structure along the radial direction is formed by partially overlapping the axial positions of the cover member 250 and the detection unit 72. In the structure shown in FIG. 3, the axial position and the radial position of each of the detected portion 71 and the cover member 250 are partially overlapped to form a maze structure along the radial direction and the axial direction between them. Is formed. Thus, while introducing the cooling air through the gap between the cover member 250 and the detection unit 72 (not shown in FIG. 1, the rear cover 8 is provided with a through hole for introducing cooling air, and through this through hole. Cooling air is introduced from the outside to the inside of the rear cover 8 and a part thereof is guided to the gap between the cover member 250 and the detection unit 72), and water penetration is suppressed from the outside through this gap to ensure water resistance. be able to.

  Thus, in the vehicle alternator 100 of the present embodiment, the detected portion 71 of the rotational position sensor 7 is provided with the cooling fan 73. For this reason, by diffusing the air in or around the brush holder 200 by the cooling fan 73, the air flow in the brush holder 200 can be promoted, and accumulation of brush wear powder in the brush holder 200 can be suppressed. . Moreover, since the cooling fan 46 is provided on the axial end surface of the rotor 4 on the slip ring 47, 48 side, the diffused brush wear powder can be effectively discharged, and the brush 61 accompanying the accumulation of the brush wear powder, It is possible to prevent abnormal wear of 62 and slip rings 47 and 48 and poor contact between them.

  In addition, by forming the cooling fan 73 as a member separate from the detected portion 71, a material suitable for the cooling fan 73 can be used, and the shape of the detected portion 71 can be simplified.

  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 cooling fan 73 is formed as a separate member from the detected portion 71, but these may be integrally formed.

  FIG. 7 is a view showing a modified example of the detected portion 71 in which the cooling fan 73 is integrated. FIG. 7A shows a state in which the detected portion 71 is exposed from the brush device 6, and FIG. 7B shows a cross-sectional structure including the brush device 6 and the detected portion 71. In the example shown in these drawings, the cooling fan 73 is integrally formed with the holder 71 b of the detected portion 71. These integrally formed holder 71b and cooling fan 73 are formed of a metal material or a resin material in which metal or ceramics is blended.

  FIG. 8 is a view showing a modified example in which the cooling fan 73 is formed on the outer periphery of the detected portion 71. FIG. 8A shows a state where the detected portion 71 is exposed from the brush device 6, and FIG. 8B shows a cross-sectional structure including the brush device 6 and the detected portion 71. In the example shown in these drawings, the cooling fan 73 is integrally formed on the outer peripheral portion of the holder 71 b of the detected portion 71. Compared with the case where the cooling fan 73 is provided around the rotation axis of the detected portion 71, the rotation length of the detected portion 71 can be simplified and the axial length thereof can be shortened. It is possible to reduce the size of the.

  FIG. 9 is a view showing a modified example in which the cooling fan 73 is formed on the lower surface of the detected portion 71. FIG. 9A shows a state where the detected portion 71 is exposed from the brush device 6, and FIG. 9B shows a cross-sectional structure including the brush device 6 and the detected portion 71. In the examples shown in these drawings, the cooling fan 73 is a centrifugal fan having a plurality of (for example, four) blades extending radially along the radial direction, and is integrally formed on the lower surface of the holder 71b of the detected portion 71. Has been.

  In the above-described embodiment, the vehicular AC generator 100 that performs a power generation operation has been described. However, the present invention can also be applied to a generator motor that drives a rotor by generating a rotating magnetic field in the stator.

It is a figure showing the whole composition of the alternator for vehicles of one embodiment. It is the figure which looked at the alternating current generator for vehicles from the rear side. It is sectional drawing of a brush apparatus and a rotation position sensor. It is a figure which shows the manufacturing process of a brush. It is the VV sectional view taken on the line of FIG. It is a perspective view of the cooling fan attached to a detection part. It is a figure which shows the modification of the to-be-detected part which integrated the cooling fan. It is a figure which shows the modification which formed the cooling fan in the outer periphery of the to-be-detected part. It is a figure which shows the modification which formed the cooling fan in the lower surface of the to-be-detected part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front side frame 2 Rear side frame 3 Stator 4 Rotor 5 Control apparatus 6 Brush device 7 Rotation position sensor 8 Rear cover 9 Pulley 44 Rotating shaft 45, 46 Cooling fan 47, 48 Slip ring 61, 62 Brush 63 Pigtail 64 Spring 71 Detected part 72 Detecting part 73 Cooling fan 100 Vehicle alternator 200 Brush holder

Claims (6)

A rotor including a rotating shaft having a pair of slip rings electrically connected to a field winding and a first cooling fan fixed to an axial end surface on the slip ring side, and slidably contact the slip ring A brush device having a pair of brushes, a brush holder in which a storage portion for storing the pair of brushes is formed, and a cover member that covers the slip ring together with the brush holder; and a rotational position cover disposed at one end of the rotating shaft. In a vehicular rotating electrical machine including a detection unit and a rotation position detection unit that detects a rotation position of the rotation position detected unit,
A vehicular rotating electrical machine comprising a second cooling fan between the rotational position detected portion and the slip ring. In claim 1,
The rotary electric machine for vehicles, wherein the second cooling fan is formed integrally with the rotational position detected portion. In claim 1,
The rotary electric machine for vehicles, wherein the second cooling fan is formed as a member different from the rotational position detected portion. In claim 2 or 3,
The vehicular rotating electrical machine, wherein the second cooling fan is formed on an outer periphery of the rotational position detected portion. In any one of Claims 1-4,
The vehicular rotating electrical machine, wherein the second cooling fan is made of a metal material. In any one of Claims 1-4,
The vehicular rotating electrical machine, wherein the second cooling fan is made of a resin material mixed with metal or ceramics.

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