JP2006166538A - Rotary electric machine for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary electric machine for a vehicle enhanced in reliability by improving the cooling performance of a power module. <P>SOLUTION: The power module 18 for power is composed of: a cooling plate 17; semiconductor elements 20, 21 mounted on the cooling plate 17 via insulating boards 22, 23; and cooling fins 17a formed on a surface opposite to installation surfaces of the insulating boards of the cooling plate 17. A clearance is formed between the installation surfaces of cooling fins of the cooling plate 17 and the external surface of a rear bracket 10, and air introduced from an air take-in part 15a of a cover 15 is introduced between the installation surfaces of the cooling fins 17a of the cooling plate 17 and the external surface of the rear bracket 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicular rotating electric machine, and more particularly to a vehicular rotating electric machine on which a power semiconductor element for electric power is mounted.

  Conventionally, for example, as described in JP-A-9-331645 and JP-A-8-336258, a substrate on which an electronic component is mounted is fixed to an end bracket of a vehicular generator, and heat generation of the electronic component is ended. What dissipates heat through a bracket is known.

JP-A-9-331645 JP-A-8-336258

  In recent years, a rotating electrical machine such as a motor generator having both a drive function and a power generation function has been developed by a single rotating electrical machine in response to the need for idling stop of an engine from an environmental viewpoint. As an electric motor, it is necessary to flow a large current of about 300 to 600 A in order to increase the output. Therefore, a large amount of current flows through a power semiconductor element for power (for example, a rectifying element, a voltage regulator, a power converter (such as an inverter)), and the amount of heat generated is also large.

  On the other hand, in a vehicular generator as described in JP-A-9-331645 and JP-A-8-336258, the flowing current is so large that electronic components are mounted on the end bracket of the vehicular generator. Even with a structure in which the substrate is fixed and the heat generated by the electronic component is dissipated through the end bracket, the electronic component can be sufficiently cooled. However, when a large current is passed through the power module using the power semiconductor element as described above, the amount of heat generated is large, and the power module cannot be cooled purely by the above-mentioned conventional method. There is a problem that the reliability of the system is lowered.

  An object of the present invention is to provide a vehicular rotating electrical machine with improved cooling performance of a power module and improved reliability.

(1) In order to achieve the above object, the present invention includes a rotor, a stator, and a front and rear bracket that rotatably supports the rotor and supports the stator with respect to the rotor via a gap. A vehicle rotation comprising: a power module that is attached to the rear bracket and is electrically connected to a stator coil of the stator; and a cover that covers the power module and is attached to the rear bracket. The electric power module includes a cooling plate, a semiconductor element mounted on the cooling plate via an insulating substrate, and a surface of the cooling plate opposite to the mounting surface of the insulating substrate. And a gap between the cooling fin mounting surface of the cooling plate and the outer surface of the rear bracket. The cooling plate is attached to the rear bracket, and the outside air introduced from the air intake portion provided in the cover is introduced between the cooling fin mounting surface of the cooling plate and the outer surface of the rear bracket. Then, the cooling fin is cooled.
With this configuration, the cooling performance of the power module can be improved, and the reliability of the rotating electrical machine can be improved.

  (2) In the above (1), preferably, the outside air is used for cooling the stator coil after passing through the cooling fin, and the cooling fin extends from the air intake portion of the cover to the stator coil. This is a ventilation guide for the flow path.

  (3) In the above (1), preferably, a resin case having a wall portion attached to the semiconductor element mounting surface side of the cooling plate and formed to surround the semiconductor element, and the surface of the semiconductor element It is made to provide the sealing material mounted so that it might cover.

  (4) In the above (3), preferably, the resin case is integrally formed with a brush holder portion for holding a brush for supplying a current to the rotor.

  ADVANTAGE OF THE INVENTION According to this invention, cooling can be improved and the rotary electric machine for vehicles with high reliability can be provided.

Hereinafter, the configuration of a rotating electrical machine for a vehicle according to an embodiment of the present invention will be described with reference to FIGS.
First, the overall configuration of the vehicular rotating electrical machine according to the present embodiment will be described with reference to FIG.

  FIG. 1 is a cross-sectional view showing the overall configuration of a vehicular rotating electrical machine according to an embodiment of the present invention. 1 to 6, the same reference numerals indicate the same parts.

  The rotating electrical machine of this embodiment is mainly composed of a rotor, a stator, and a bracket constituting a housing. First, the configuration of the rotor will be described. A claw-shaped rotor core 3 fitted with a field coil 4 is fixed to the rotor shaft 1. Fins 11 are fixed to both ends of the rotor 3. Both ends of the rotor shaft 1 are held by a pair of brackets (front bracket, rear bracket) 9 and 10 via bearings 7 and 8.

  A slip ring 12 for supplying a current to the field coil 4 is disposed around one end of the rotor shaft 1 protruding from the rear bracket 10. A field current is supplied to the slip ring 12 via the brush 13. A magnet 16 is attached to one end of the rotor shaft 1 to detect the rotation of the rotor, and rotates together with the rotor shaft 1. A Hall IC 19a is mounted on the rotation detection circuit board 19 through a gap with the magnet 16. The change in the magnetic field generated by the rotation of the magnet 16 is detected by the Hall IC 19a, and the rotation of the rotor is detected. A pulley 2 is fixed to the other end of the rotor shaft 1.

  Next, the configuration of the stator will be described. A stator coil 6 is attached to the stator core 5. The stator core 5 is disposed with respect to the claw-type rotor 3 via a minute gap and is sandwiched between the front bracket 9 and the rear bracket 10. The stator coil 6 includes a U-phase, V-phase, and W-phase three-phase coil that is Y-connected to form a set of stator coils, and two sets of the stator coils are provided.

  The brush 13 is held by a resin brush holder 24c having insulating properties. The power module 18 and the brush holder 24 c are integrally screwed to the outer surface of the rear bracket 10. At this time, a gap is formed between the bottom surface of the power module (metal plate portion serving as a cooling plate) and the outer surface of the rear bracket 10.

  Further, an output terminal 14 for outputting electric power induced in the stator coil 6 is attached to the outer surface of the rear bracket 10. Further, the power module 18 and the magnet 16 are covered with a rear cover 15. As will be described later with reference to FIG. 5, a plurality of external air intake portions 15 a are formed in the circumferential direction of the outer periphery of the rear cover 15. When the rotor 3 is rotated, the cooling fins 11 are rotated so that outside air is introduced from the external air intake portion 15a provided on the outer peripheral portion of the cover 15, and the power module bottom surface (metal plate portion serving as a cooling plate) side and The outside air is introduced through a gap between the outer surfaces of the rear bracket 10 to cool the bottom surface of the power module, and the outside air is introduced into the rear bracket 10 and the front bracket 9 (that is, inside the rotating electrical machine). Introduced, heat generated from the field coil 4 and the stator core 5 is taken away to increase power generation efficiency.

  That is, in this embodiment, the bottom surface of the power module is cooled by the outside air introduced through the gap between the bottom surface (metal plate portion serving as a cooling plate) side of the power module and the outer surface of the rear bracket 10. There are features. In the conventional system, the circuit board of the electronic component corresponding to the bottom surface of the power module is attached to the outer surface of the end bracket. And external air is introduce | transduced into the inner surface side (inner surface side of a rotary electric machine) of an end bracket. Therefore, the introduced outside air becomes a temperature higher than room temperature due to the heat generated from the field coil 4 and the stator core 5, and the circuit board of the electronic component is cooled by the outside air at this temperature. When a power semiconductor element for electric power that flows a large current of about 600 A is used, the amount of heat generation is large and sufficient cooling cannot be performed. On the other hand, in this embodiment, since the power semiconductor element for electric power is directly cooled by the outside air at room temperature before being heated by the heat of the field coil 4 and the stator core 5, the cooling efficiency is improved. The reliability of the power module can be improved.

  Next, the detailed configuration of the power module used in the vehicular rotating electrical machine according to the present embodiment will be described with reference to FIGS.

  FIG. 2 is a front view showing a configuration of a power module used in the vehicular rotating electrical machine according to the embodiment of the present invention. FIG. 3 is a partial cross-sectional view showing a configuration of a power module used in a rotating electrical machine for a vehicle according to an embodiment of the present invention, showing a cross section taken along the line AA in FIG. 2 and a cross section taken along the line BB in FIG. FIG. 4 is a rear view showing the configuration of the power module used in the vehicular rotating electrical machine according to the embodiment of the present invention.

  As shown in FIG. 3, the power module 18 mainly includes a resin case 24 in which a metal cooling plate 17 and a resin brush holder 24c are also integrally formed.

  Insulating substrates 22 and 23 are fixed on the cooling plate 17. The semiconductor elements 20 and 21 are mounted on the insulating substrates 22 and 23 by soldering. The semiconductor elements 20 and 21 are respectively composed of power semiconductor switching elements 20a, 20b, 20c, 20d, 20e, and 20f and power semiconductor switching elements 21a, 21b, 21c, 21d, 21e, and 21f. . These semiconductor elements are composed of, for example, a MOS (complementary metal oxide semiconductor) -FET. When a rotating electrical machine is used as an electric motor, these switching elements are used to convert a DC voltage from a DC power source (for example, a battery) into an AC voltage. Moreover, when using a rotary electric machine as a generator, these switching elements are used in order to convert the alternating voltage which is the output of a generator into a direct voltage, and to store in a battery.

  Here, as described above, since the stator coil is composed of two sets of Y-connected coils, for example, the semiconductor element 20 is provided for the first set of coils. For example, the power semiconductor switching elements 20a and 20b are provided in the U-phase upper arm and the lower arm, the semiconductor switching elements 20c and 20d are provided in the V-phase upper arm and the lower arm, and the semiconductor switching elements 20e and 20f are , W phase upper arm and lower arm. The semiconductor element 21 is provided for the second set of coils.

  On the other hand, the resin case 24 has a wall portion 24a on its outer periphery. As shown in FIG. 3, the wall 24 a is provided on the side opposite to the surface where the resin case 24 contacts the cooling plate 17. In the resin case 24, a bus bar 25 is integrally embedded by molding. The semiconductor elements 20 and 21 and the bus bar 25 are connected by wire bonding 26. A connecting portion 25a is provided at the end of the bus bar 25 so as to protrude from the wall portion 24a. The connection part 25a is electrically connected to the stator coil 6 as shown in FIG.

  The resin case 24 is also integrally formed with a brush holder 24c.

  As shown in FIG. 3, the cooling plate 17 and the resin case 24 are bonded and integrated with an adhesive resin or the like. Since the wall 24a is provided so as to surround the outer periphery of the semiconductor element 21 attached to the cooling plate 17, the surface of the power semiconductor elements 20, 21 is covered with a sealing material such as silicon gel 27, and the semiconductor surface When the wall 24a is protected, the wall 24a functions as a flow stopper.

  As shown in FIG. 1, the cooling plate 17 and the resin case 24 are screwed to the rear bracket 10. At this time, in order to prevent the resin case 24 from being cracked by the tightening torque of the screw, as shown in FIG. 3, a metal ring is embedded in the screw mounting portion of the resin case 24 by molding. Yes.

  As shown in FIG. 4, a plurality of cooling fins 17 a are formed radially on the back side of the cooling plate 17. The height of the cooling fins 17a is the same as the height of the mounting screw portion for the rear bracket 10 as shown in FIG. Accordingly, the outside air introduced from the plurality of external air intake portions 15a formed in the circumferential direction of the outer periphery of the rear cover 15 is on the bottom surface (metal plate portion serving as a cooling plate) side of the power module and the outer surface of the rear bracket 10. From the gap between them, it proceeds along the cooling fins 17a in the direction of the rotary shaft 1 of the rotating electrical machine, and the bottom surface of the power module 18 is cooled. That is, the cooling fin 17 functions as a ventilation guide. Further, as shown in FIG. 1, the outside air is introduced into the rear bracket 10 and the front bracket 9 (that is, inside the rotating electrical machine) from the opening of the rear bracket 10 to cool the field coil 4 and the stator core 5. To do.

  As shown in FIG. 1, the metal cooling plate 17 is attached to the metal rear bracket 10. Since the power module 18 is connected to the cooling plate 17, the power module 18 is grounded to the vehicle body via the rear bracket 10. On the other hand, the rear bracket 10 is heated by the heat generated by the stator coil 6 and the like. In order to reduce the amount of heat generated by the stator coil and the like transmitted to the cooling plate 17, as shown in FIG. 4, the electrical connection between the rear bracket 10 and the cooling plate 17 is made by using only three attachment portions 17 b. In addition, the effect of heat is transmitted as much as possible.

  Next, the configuration of the rear cover 15 used in the vehicular rotating electrical machine according to the present embodiment will be described with reference to FIGS. 5 and 6.

  FIG. 5 is a perspective view showing the configuration of the rear cover used in the vehicular rotating electrical machine according to the embodiment of the present invention. FIG. 6 is a cross-sectional view showing a state in which the pipe is attached to the rear cover used in the vehicular rotating electrical machine according to the embodiment of the present invention.

  As shown in FIG. 5, a plurality of external air intake portions 15 a are formed in the circumferential direction of the outer periphery of the rear cover 15. Further, the rear cover 15 is formed with a pipe attachment portion 15b for ventilation. As shown in FIG. 6, a ventilation pipe 28 is attached to the rear cover 15, and the atmospheric pressure when the slip ring 12 and the brush 14 slide is set to the same level as the atmosphere. Thereby, abnormal wear of the slip ring 12 can be prevented.

As described above, according to the present embodiment, the cooling plate is cooled by the outside air introduced into the gap between the rear bracket and the cooling plate, so that the cooling efficiency of the power module attached to the cooling plate is improved. , Reliability can be improved.

1 is a cross-sectional view illustrating an overall configuration of a vehicular rotating electrical machine according to an embodiment of the present invention. It is a front view which shows the structure of the power module used for the rotary electric machine for vehicles by one Embodiment of this invention. It is a fragmentary sectional view which shows the structure of the power module used for the rotary electric machine for vehicles by one Embodiment of this invention. It is a rear view which shows the structure of the power module used for the rotary electric machine for vehicles by one Embodiment of this invention. It is a perspective view which shows the structure of the rear cover used for the rotary electric machine for vehicles by one Embodiment of this invention. It is sectional drawing which shows the attachment state of the pipe with respect to the rear cover used for the rotary electric machine for vehicles by one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 ... Rotor 9, 10 ... Bracket 11 ... Fin 18 ... Power module 15 ... Rear cover 17 ... Cooling plate 17a ... Radiating fin 20, 21 ... Power semiconductor element 22, 23 ... Insulating substrate

Claims (4)

A rotor, a stator, a rotor that rotatably supports the rotor, and a front and rear bracket that supports the stator with respect to the rotor via a gap; a stator coil of the stator that is attached to the rear bracket; A rotating electrical machine for a vehicle comprising an electrically connected power module for power, and a cover for covering the power module for power and attached to the rear bracket,
The power module for power includes a cooling plate, a semiconductor element mounted on the cooling plate via an insulating substrate, and a cooling fin formed on a surface of the cooling plate opposite to the mounting surface of the insulating substrate. Consists of
A clearance is provided between a mounting surface of the cooling fin of the cooling plate and an outer surface of the rear bracket, and the cooling plate is attached to the rear bracket and is introduced from an air intake portion provided in the cover. Is introduced between the mounting surface of the cooling fin of the cooling plate and the outer surface of the rear bracket to cool the cooling fin. The rotating electrical machine for a vehicle according to claim 1,
The outside air is used for cooling the stator coil after passing through the cooling fins,
The rotating electrical machine for a vehicle according to claim 1, wherein the cooling fin serves as a ventilation guide for a flow path from the air intake portion of the cover to the stator coil. The rotating electrical machine for a vehicle according to claim 1,
A resin case having a wall portion attached to the semiconductor element mounting surface side of the cooling plate and formed so as to surround the periphery of the semiconductor element;
A vehicular rotating electrical machine comprising a sealing material mounted so as to cover a surface of the semiconductor element. The rotating electrical machine for a vehicle according to claim 3,
The rotating electrical machine for a vehicle according to claim 1, wherein the resin case is integrally formed with a brush holder portion for holding a brush for supplying a current to the rotor.

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