JP2017055660A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine which inhibits transmission of heat to a control circuit to improve the cooling performance.SOLUTION: A motor generator 100 for a vehicle includes: a power converter 5 including a power element; a control circuit 8 which controls the power converter 5; frames 1, 2 for housing a rotor 4 and a stator 3 to which a cooling fan 46 is attached; and a cooling fin 6 for cooling the power converter 5. The power converter 5 is provided on one surface of the cooling fin 6 which is located at an opposite side of the cooling fan 46. Passages of cooling air, which is taken into the frame 2 by the cooling fan 46, are formed between the frame 2 and the cooling fin 6 and between the control circuit 8 and the power converter 5.SELECTED DRAWING: Figure 1

Description

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

  Conventionally, a structure in which a rotating electrical machine and a control circuit for controlling the rotating electrical machine are integrated has been proposed for miniaturization. For example, a rotating electrical machine is known in which a control board including a control circuit and a bracket of the rotating electrical machine are fastened through a metallic fixing member having high rigidity (see, for example, Patent Document 1).

Japanese Patent No. 4402091 JP 2011-239542 A JP 2004-215368 A JP 2013-102591 A JP 2010-16965 A JP 2001-21663 A

  By the way, in the structure disclosed in Patent Document 1, since both the control board and the bracket are fastened to a highly rigid metallic fixing member, the heat generated in the rotating electrical machine is generally highly heat conductive. There is a problem that the cooling performance of the control circuit is deteriorated because it is transmitted to the control board through a housing formed of a material (for example, aluminum) and a metal fixing member.

  The present invention has been created in view of such a point, and an object of the present invention is to provide a rotating electrical machine that can improve the cooling performance by suppressing the transfer of heat to a control circuit.

  In order to solve the above-described problem, the rotating electrical machine of the present invention includes a power circuit, a control circuit, a frame, and a cooling fin. The power circuit includes a power element. The control circuit controls the power circuit. The frame houses a rotor and a stator to which a cooling fan is attached. The cooling fin cools the power circuit. The power circuit is provided on one side of the cooling fin on the side opposite to the cooling fan. A passage for cooling air taken into the frame by a cooling fan is formed between the frame and the cooling fin and between the control circuit and the power circuit.

1 is a diagram illustrating an overall configuration of a vehicular motor generator according to an embodiment. FIG. It is a connection diagram of the motor generator for vehicles of this embodiment containing a power converter. It is a figure which shows the modification of a structure around a cooling fin and a fixing member.

  Hereinafter, a vehicle motor generator according to an embodiment to which a rotating electrical machine of the present invention is applied will be described in detail with reference to the drawings. A vehicle motor generator 100 according to an embodiment shown in FIG. 1 includes a front frame 1, a rear frame 2, a stator 3, a rotor 4, a power converter 5, a cooling fin 6, a brush device 7, a control circuit 8, and a rear cover. 9 and pulley 10 and the like.

  The front frame 1 and the rear frame 2 are for accommodating and supporting the rotor 4 and the stator 3, both having a bowl shape, and sandwiching the stator 3 with these openings facing each other. In the state, they are fixed to each other by a plurality of bolts. These front frame 1 and rear frame 2 are formed by, for example, aluminum die casting. The stator 3 includes a stator core 31 disposed opposite to the rotor 4 and a stator winding 32 provided on the stator core 31.

  The rotor 4 includes a field winding 41 and a rotating shaft 44 that magnetize pole cores 42 and 43 as field poles, and a pair of housings housed in bearing boxes provided on the front frame 1 and the rear frame 2 respectively. It is held rotatably by the bearing. Cooling fans 45 and 46 are attached to the axial end surfaces of the pole cores 42 and 43. Further, the pulley 10 is coupled to the front end of the rotating shaft 44 by a nut. Further, a pair of slip rings connected to both ends of the field winding 41 are provided at the rear end of the rotating shaft 44 located outside the rear frame 2. Excitation current is supplied to the field winding 41 via these slip rings and the brush device 7.

  The power converter 5 is a power circuit including a power element, is connected to the stator winding 32, converts an AC electromotive force induced in the stator winding 32 into a direct current, and a battery (not shown). 1), at least one of the operations of converting the DC power stored in AC to AC and supplying it to the stator winding 32 is performed.

  The cooling fin 6 is made of metal and is fastened to the rear frame 2 to cool the power converter 5. The cooling fin 6 includes a flat plate portion 61 on which the power converter 5 is mounted on one surface opposite to the rear frame 2, and a fin protruding portion protruding on the other surface (rear frame 2 side) of the flat plate portion 61. 62, and these are integrated. For example, the cooling fins 6 are formed by aluminum die casting. The cooling fins 6 are cooled by the cooling air taken into the rear frame 2 by the rear-side cooling fan 46 that rotates together with the rotor 4.

  As shown in FIG. 2, the power converter 5 includes a plurality of (for example, three) low-side switching elements 53a, 53c, and 53e and a plurality of (for example, three) high-side switching elements 53b, 53d, and 53f that are power elements. It is comprised including.

  Each of the three low-side switching elements 53a, 53c, 53e and the three high-side switching elements 53b, 53d, 53f is, for example, an N-channel MOS-FET, and is formed on one surface of the cooling fin 6. It is arranged directly or via a wiring board.

  As shown in FIG. 2, the power converter 5 is a three-phase bridge circuit including three low-side switching elements 53a, 53c, and 53e and three high-side switching elements 53b, 53d, and 53f. It is connected to a stator winding 32 that is a three-phase winding.

  The bridge circuit operates as a three-phase full-wave rectifier that performs a rectification operation by performing a synchronous rectification and converting an AC voltage induced in the stator winding 32 into a direct current during a power generation operation. In addition, the bridge circuit converts the DC voltage applied from the battery 18 into a three-phase AC voltage by performing on / off control of the six switching elements for each phase of the stator winding 32 during electric operation. It operates as an inverter circuit.

  The control circuit 8 controls the vehicle motor generator 100 to perform a power generation operation or an electric operation, and includes a reference voltage adjustment circuit 8A and an inverter control circuit 8B. The reference voltage adjustment circuit 8A adjusts the field current supplied to the rotor field winding during power generation so that the output voltage of the vehicular motor generator 100 becomes the reference voltage (adjustment voltage). Control.

  During the power generation operation, the inverter control circuit 8B generates a synchronous rectification control signal or the like that causes the power converter 5 to perform synchronous rectification by performing on / off control of the six switching elements 53a to 53f included in the power converter 5. Further, during the electric operation, the six switching elements 53a to 53f included in the power converter 5 are on / off controlled, and a control signal (gate input signal) for generating a three-phase alternating current is generated by the power converter 5.

  By the way, in this embodiment, the control circuit 8 is housed in a resin case 82 in which a metal (for example, aluminum) fixing member 81 is insert-molded. The control circuit 8 is fastened to the fixing member 81 using a metal screw 83. In the example shown in FIG. 1, the control circuit 8 includes a control board 8 a, and the control board 8 a is fastened to the fixing member 81 with screws 83. The fixing member 81 is fastened to the cooling fin 6 by a bolt 84 that is a metal fastening member.

  Thus, in the vehicle motor generator 100 of the present embodiment, the fixing member 81 that fixes the control circuit 8 is fastened to the rear frame 2 via the cooling fins 6, and therefore, the rear frame 2 to the control circuit 8 is Heat transfer can be suppressed, and the cooling performance of the control circuit 8 can be improved. Further, since the control circuit 8 can be fixed via the metal fixing member 81 or the cooling fin 6, the amplification of vibration transmitted from the rear frame 2 to the control circuit 8 during the operation of the vehicle motor generator 100 can be performed. This can be suppressed as compared with a case where a member formed of a resin material is interposed therebetween.

  In particular, since the cooling fins 6 are cooled by the cooling air taken into the rear frame 2 by the cooling fan 46 that rotates together with the rotor 4, the temperature of the cooling fins 6 is reliably lowered to reduce the heat reception of the control circuit 8. Can do.

  By the way, the cooling performance of the control circuit 8 can be further improved by devising the material of the fixing member 81 and the bolt 84 described above.

(Modification 1)
The bolt 84 as a fastening member is formed of a material having a lower thermal conductivity than the cooling fin 6. For example, the fixing member 81 and the cooling fin 6 are formed using aluminum, and the bolt 84 is formed of stainless steel having a lower thermal conductivity than aluminum. Thereby, it is possible to make it difficult for heat to be transmitted from the cooling fin 6 to the fixing member 81 via the bolt 84.

(Modification 2)
The fixing member 81 is formed of a metal material having a lower thermal conductivity than the cooling fin 6. For example, the cooling fin 6 is formed using aluminum, and the fixing member 81 is formed of stainless steel. In this case, the bolts 84 may also be formed of stainless steel, which is a metal material having a lower thermal conductivity than the cooling fins 6. Thereby, it is possible to make it difficult for heat to be transmitted from the cooling fin 6 to the control circuit 8 via the fixing member 81.

(Modification 3)
As shown in FIG. 3, a cylindrical member 85 as a metal member having a lower thermal conductivity than the cooling fin 6 is interposed between the fixing member 81 and the cooling fin 6. For example, when the fixing member 81 and the cooling fin 6 are formed using aluminum, a cylindrical member 85 formed of stainless steel is disposed therebetween. In this case, the bolts 84 may also be formed of stainless steel, which is a metal material having a lower thermal conductivity than the cooling fins 6. Thereby, it is possible to make it difficult for heat to be transmitted from the cooling fin 6 to the fixing member 81 via the cylindrical member 85.

  In addition, in the first to third modifications described above, in addition to the case where the control circuit 8 is implemented alone, the heat receiving from the cooling fin 6 to the control circuit 8 is further reduced by combining two or three, thereby cooling the control circuit 8. The property can be further improved.

  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 embodiments, the motor generator for a vehicle that performs an electric operation and a power generation operation has been described. Can be applied.

  In the embodiment described above, the power converter including one bridge circuit has been described as illustrated in FIG. 2, but the number of bridge circuits may be two or more. Moreover, although the specific example which forms the cooling fin 6 and the fixing member 81 with aluminum and the specific example which forms the volt | bolt 84 with stainless steel was demonstrated in embodiment mentioned above, these are made of other materials (for example, copper and iron). You may make it form using.

  Further, the case where a plurality of low-side switching elements and high-side switching elements, which are power elements, are arranged directly on one surface of the cooling fin 6 or via a wiring board has been described. One set corresponding to the same phase winding The low-side switching element and the high-side switching element may be modularized and arranged on the cooling fin 6.

  As described above, according to the present invention, heat transfer from the frame to the control circuit can be suppressed, and the cooling performance of the control circuit can be improved.

2 Rear frame 3 Stator 4 Rotor 5 Power converter 6 Cooling fin 8 Control circuit 46 Cooling fan 81 Fixing member 84 Bolt 85 Cylindrical member

Claims (9)

A power circuit (5) including a power element;
A control circuit (8) for controlling the power circuit;
A frame (2) that houses a rotor (4) and a stator (3) to which a cooling fan (46) is attached;
Cooling fins (6) for cooling the power circuit,
The power circuit is provided on one side of the cooling fin on the side opposite to the cooling fan,
A rotating electrical machine characterized in that a passage of cooling air taken into the frame by the cooling fan is formed between the frame and the cooling fin and between the control circuit and the power circuit.   The brush device (7) for supplying current to the rotor is provided in a cooling air passage formed between the control circuit and the power circuit. Rotating electric machine.   The rotating electrical machine according to claim 1, further comprising an opening on a radially outer side of the cooling fin.   The rotating electrical machine according to claim 1, wherein the control circuit is housed in a resin case. A fixing member (81) for fixing the control circuit to the cooling fin;
The rotation according to any one of claims 1 to 4, wherein the fixing member is fastened to the cooling fin using a fastening member (84) having a lower thermal conductivity than the cooling fin. Electric.   The rotating electrical machine according to claim 5, wherein a member (85) having a lower thermal conductivity than the cooling fin is interposed between the fixing member and the cooling fin.   The rotating electrical machine according to claim 5 or 6, wherein the fixing member is made of a metal material having a lower thermal conductivity than the cooling fin. The cooling fin is made of aluminum,
The rotating electrical machine according to claim 7, wherein the fixing member is a screw formed of stainless steel.   The rotating electrical machine according to any one of claims 1 to 8, wherein the cooling fin is made of metal and fastened to the frame.

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