ROTATING ELECTRIC MACHINE

Abstract

The invention aims to provide a rotating electrical machine that is inexpensive and miniaturized while improving the cooling performance of a rotor, a power supply unit (300) being fixed on the axial side of a shaft (4) in a support (2) and a permanent magnet (10) being arranged adjacent to the lead side in the direction of rotation of a claw-shaped portion of a magnetic pole (921) of a magnetic pole (92) on the side where the power supply unit (300) is located. Figure 2

Description

Title of the invention: ROTATING ELECTRIC MACHINE

[0001] BACKGROUND OF THE INVENTION

[0002] 1. SCOPE OF THE INVENTION

[0003] The present application relates to a rotating electrical machine in which an electrical power supply unit is integrated.

[0004] 2. DESCRIPTION OF RELATED ART

[0005] In a vehicle alternating current (AC) generator of the magnet combination type in which a permanent magnet is arranged between claw portions of magnetic poles of a Lundell-type rotor, a structure is known in which a configuration is made such that the total number of inter-pole magnets is less than the number of claw-shaped magnetic poles.

[0006] For example, in a rotating electrical machine described in patent document 1, a rotor includes a field magnet provided between a first claw-shaped magnetic pole and a second claw-shaped magnetic pole and the field magnet is arranged alternately.

[0007] Patent document 1: JP-A-H11(1999)-98787

[0008] When such a structure is adopted in a rotating electrical machine incorporating a power supply unit, the pressure drop on the power supply unit side is greater than on the opposite side, and the amount of air intake to an electric motor on the power supply unit side is less than on the opposite side. Consequently, when the magnet is arranged in a position where the cooling air supplied from the opposite side of the power supply unit is blocked, the pressure drop increases and the amount of cooling air flow is reduced; thus, the heat transfer coefficient is reduced. Furthermore, an air intake orifice must be enlarged, resulting in an increase in size and weight.

[0009] Furthermore, particularly when the rotating electrical machine is mounted in the engine compartment of a motor vehicle, the rotating electrical machine must be placed in a limited space. In a type of vehicle where radial space can only be loosely secured, this leads to problems in that components interfere with each other; there is a problem in that a working space for attaching a connector to an external device or a fixing screw cannot be secured; and, in the worst-case scenario, there is a case where the rotating electrical machine cannot be placed due to size constraints. As just described, there is a problem in that mounting is limited due to the layout in the engine compartment. In addition, a high cooling property is required in an electric motor mounted on a hybrid (HV) or similar vehicle; in the case of a significant temperature rise, a current density must be reduced and this leads to a deterioration of performance; and / or, there is a problem in that a highly heat-resistant component is used and consequently this leads to an increase in cost. Summary of the invention

[0010] In view of the aforementioned problem, one objective of the present application is to propose a rotating electrical machine that is cheap and miniaturized while improving the cooling performance of a rotor.

[0011] The rotating electrical machine disclosed in this application is a machine rotating electric motor comprising: a rotor configured to have magnetic poles in which a plurality of claw-shaped magnetic pole portions are provided on its outer circumference, a field winding wound around the magnetic poles, and a shaft which is in rotation as a single unit with the magnetic poles and the field winding; a stator configured to have a stator core arranged in a face-to-face relationship with the outer circumference of the magnetic poles, and a stator winding wound around the stator core; a permanent magnet configured to be disposed between the adjacent claw-shaped magnetic pole portions of the magnetic poles, and to be magnetized in a direction reducing a leakage magnetic flux between the adjacent claw-shaped magnetic pole portions;a cooling fan configured to be provided on at least one of the axial sides of the shaft in the magnetic poles, and to cool the field winding and the permanent magnet; supports configured to hold the stator and rotor, and to support the rotating shaft; and a power supply unit configured to provide power to the stator winding or the field winding. In the rotating electrical machine, the power supply unit is configured to be fixed to the axial side of the shaft of the support; and the permanent magnet is configured to be arranged on the lead side in the direction of rotation of the claw-shaped portion of the magnetic pole on the side where the power supply unit is provided.

[0012] According to the rotating electrical machine disclosed in this application, the permanent magnet is arranged on the feed side in the direction of rotation of the claw-shaped magnetic pole portions of the magnetic pole on the power supply unit side, thereby enabling cooling without blocking cooling air supplied from the side opposite the power supply unit where the airflow is significant. Furthermore, a property of Cooling of the field winding is improved, and consequently, continuous output can be enhanced. Furthermore, the cooling performance of the permanent magnet can be improved, allowing the use of a lower-cost permanent magnet. Brief description of the drawings

[0013]

[0014] [Fig. 1] is a cross-sectional view of part of interest of a rotating electrical machine according to embodiment 1;

[0015] [Fig.2] is a plan view showing an example of a rotor in an arrangement lateral in the rotating electrical machine according to embodiment 1;

[0016] [Fig.3] is a view on which the rotor in the rotating electrical machine according to the embodiment 1 is viewed from the power supply unit side;

[0017] [Fig.4] is a plan view showing an example of the rotor in an arrangement longitudinal in the rotating electrical machine according to embodiment 1;

[0018] [Fig.5] is a typical view intended to explain an airflow of cooling through the rotor according to embodiment 1;

[0019] [Fig.6] is a plan view showing a rotor in a lateral arrangement in a rotating electric machine according to embodiment 2;

[0020] [Fig.7] is a view in which the rotor is seen from the power unit side electrical in the rotating electrical machine according to embodiment 2;

[0021] [Fig.8] is an overview view showing a part of interest of a rotor in a rotating electrical machine according to an embodiment 3;

[0022] [Fig.9] is an overview view showing a part of interest of a rotor in a rotating electrical machine according to embodiment 4;

[0023] [Fig. 10] is an overview view showing a part of interest of a rotor in a rotating electrical machine according to an embodiment 5; and

[0024] [Fig. 11] is a cross-sectional view of part of interest of a rotating electrical machine according to an embodiment 6. DETAILED DESCRIPTION OF THE INVENTION

[0025] Preferred embodiments of a rotating electrical machine according to the present application will be described below with reference to drawings. In each drawing, identical or equivalent elements and portions will be described with the same numerical references (and letters) assigned to them. In this regard, a component portion in one drawing and the identical and / or equivalent component portion in another drawing are each shown at an independent size and scale.

[0026] Embodiment 1

[0027] Embodiment 1 will be described on the basis of drawings. [Fig. 1] is a cross-sectional view of a part of interest of a rotating electrical machine according to embodiment 1. [Fig. 2] is a plan view showing an example of a rotor according to this embodiment 1. [Fig. 3] is a view in which the rotor in the rotating electrical machine according to embodiment 1 is seen from the power supply side. [Fig. 4] is a plan view showing an example of the rotor in a longitudinal arrangement in the rotating electrical machine according to embodiment 1. [Fig. 5] is a typical view intended to illustrate the flow of cooling air through the rotor according to embodiment 1.

[0028] In [Fig. 1], a direction in which a shaft extends, namely, an up-down direction, serves as the axial direction; the radial direction of the rotor and stator, namely, a right-left direction, serves as the radial direction; an upper axial direction serves as the rear side; and a lower axial direction serves as the front side. Furthermore, these directions are also referred to as the axial direction, radial direction, rear side, and front side of an electric motor, respectively.

[0029] In [Fig. 1], the rotating electrical machine consists of an electric motor 200 and a power supply unit 300 which provides power to an electric motor 200. The electric motor 200 comprises: supports serving as a housing which consists of a support on the side opposite the power supply unit (hereinafter referred to as the "front support") 1 and a support on the side of the power supply unit (hereinafter referred to as the "rear support") 2; a stator 3 having a stator core 31 and a stator winding 32; and a rotor 6 having a shaft 4 and a field winding 5. The stator 3 is supported and fixed by an end portion of the front support 1 and an end portion of the rear support 2; and the rotor 6 is arranged inside the stator 3.The shaft 4 of the rotor 6 is supported in rotation by a bearing 71 provided on the front support 1 and a bearing 72 provided on the rear support 2; and the rotor 6 is configured so as to be able to rotate coaxially with respect to the stator 3. The power supply unit 300 provides power to at least either the stator winding 32 or the field winding 5.

[0030] A cooling fan 81 is fixed on the side opposite the power supply unit (hereinafter referred to as the "front side") in the axial direction of the rotor 6; and a cooling fan 82 is fixed on the side of the power supply unit (hereinafter referred to as the "rear side"). A pulley (not shown in the drawings) is attached to a load-side end portion of the shaft 4, namely, on the outside of the front side of the front support 1. The pulley is coupled to a rotating shaft of a motor via a belt (not shown in the drawings) to transfer rotational energy.

[0031] The rotor 6 is configured by combining a first magnetic pole 91 (the front side) with a second magnetic pole 92 (the rear side); the field winding 5 is arranged in an internal space formed by the first magnetic pole and the second magnetic pole; the first magnetic pole has a plurality of first claw-shaped magnetic pole portions 911 arranged with a space in the direction of rotation of the rotor; the second magnetic pole has a plurality of second claw-shaped magnetic pole portions 921 arranged with a space in the direction of rotation of the rotor; a permanent magnet 10 is provided in certain inter-magnetic pole portions, each existing between the first claw-shaped magnetic pole portion 911 and the second claw-shaped magnetic pole portion 921;and the first magnetic pole 91 and the second magnetic pole 92 are combined so that the first claw-shaped portion of the magnetic pole 911 and the second claw-shaped portion of the magnetic pole 921 are alternately engaged.

[0032] The permanent magnet 10 is characterized in that it is arranged adjacent to the leading side in the direction of rotation of the second claw-shaped magnetic pole portions 921 of the second magnetic pole 92.

[0033] In the rotating electric machine with integrated power supply unit, when the rotor 6 is set in rotation and driven, the cooling fans 81, 82 are also set in rotation in a corresponding manner and flow paths are configured as shown by arrows on [Fig.1].

[0034] The front support 1 comprises: a plurality of opening portions 12 (hereinafter referred to as "exhaust opening portions 12") which are provided circumferentially in a distributed manner over a portion on the radial outside of the front side cooling fan 81; and a plurality of opening portions 11 (hereinafter referred to as "air intake opening portions 11") which are provided circumferentially in a distributed manner over a portion on the front side.

[0035] The rear support 2 comprises: a plurality of opening portions 22 (hereinafter referred to as "exhaust opening portions 22") which are provided circumferentially in a distributed manner over a portion on the radial outside of the rear side cooling fan 82; and a plurality of opening portions 21 (hereinafter referred to as "air intake opening portions 21") which are provided circumferentially in a distributed manner over a portion on the rear side.

[0036] Cooling air W1 comprises: cooling air W11 which passes through the air intake opening portions 11 and is discharged from the exhaust opening portions 12; and cooling air W12 which passes through between portions of rotor claw 6 and is evacuated from the exhaust opening portions 22.

[0037] Cooling air W2 comprises: cooling air W21 which passes through the power supply unit, passes through the air intake opening portions 21, and is discharged from the exhaust opening portions 22; and cooling air W22 which passes through between the rotor claw portions 6 and is discharged from the exhaust opening portions 12.

[0038] As with the cooling air W1 and cooling air W2, the cooling air W2 passes through the power supply unit 300; thus, the pressure drop of the cooling air W2 is greater than that of the cooling air W1, and the amount of airflow in the cooling air W1 is greater than that in the cooling air W2. Consequently, the amount of airflow of the cooling air W12 that cools the rotor 6 is greater than that of the cooling air W22.

[0039] In response to the rotation of a rotor 6, the cooling air W12 is produced by adjacent air pressure (direction: PI) by the first claw-shaped magnetic pole portions 911 and the cooling air W22 is produced by adjacent air pressure (direction: P2) by the second claw-shaped magnetic pole portions 921.

[0040] The power supply unit 300 is arranged on the rear side of the electric motor 200 and is fixed to the electric motor 200. The power supply unit 300 comprises: an inverter which has a plurality of power semiconductor elements and performs a direct current (DC) / alternating current (AC) conversion between a DC power supply and a plurality of winding phases; a control circuit which performs a switching control on / off of the power semiconductor elements; a pair of brushes 14 which makes contact with a pair of slip rings 13 provided at a portion of the shaft 4 projecting from the rear support 2 towards the rear side; and a power semiconductor element for the field winding, which switches on / off a power to be supplied to the field winding 5 via the brush 14 and the slip ring 13.The power semiconductor elements (switching elements) for the field winding perform on / off control via the control circuit and generate heat through the operation of the rotating electrical machine.

[0041] According to the present embodiment, the permanent magnet 10 is arranged in a position where the cooling air W22 is produced and the cooling air W12 with a large quantity of airflow is not blocked; thus, the rotor 6 and the stator 3 can be cooled efficiently by being able to efficiently utilize the air from Cooling. Furthermore, the cooling air W21, which passes through the power supply unit 300 serving as a heat source, is not drawn towards the rotor 6; thus, cooling efficiency is improved by not using high-temperature air as cooling air. In order to produce the same amount of airflow as in a case where the permanent magnet 10 is arranged adjacent to the leading side in the direction of rotation of the claw-shaped magnetic pole portions of the first magnetic pole, the overall pressure loss must be reduced, resulting in an increase in size; while at the same time, a reduction in size and lower production costs can be achieved.In addition, the power supply unit is less likely to receive heat from the electric motor due to increased cooling efficiency of the electric motor; thus, the cooling efficiency of the power supply unit is also improved; a highly heat-resistant component does not need to be used, and the cost / performance ratio is improved.

[0042] Embodiment 2

[0043] Fig. 6 is a plan view showing a rotor in a lateral arrangement in a rotating electrical machine according to an embodiment 2. Fig. 7 is a view in which the rotor is seen from the side of the power supply unit in the rotating electrical machine according to an embodiment 2.

[0044] A permanent magnet 10 is arranged adjacent to the leading side in the direction of rotation of claw-shaped magnetic pole portions 921 of a second magnetic pole; and an inter-pole magnetic portion where the permanent magnet 10 is inserted and an inter-pole magnetic portion where the permanent magnet 10 is not inserted are arranged alternately in the direction of rotation.

[0045] According to the present embodiment, the permanent magnets 10 can be arranged in maximum numbers without obstructing the efficient use of cooling air; thus, magnetic leakage flux is reduced and output is improved. Furthermore, the cooling air W21, which passes through a power supply unit 300 serving as a heat source and is heated, is prevented from entering a maximum of one rotor 6; thus, the cooling efficiency of an electric motor is also increased.

[0046] Embodiment 3

[0047] Fig. 8 is an overview view showing a part of interest of a rotor in a rotating electrical machine according to an embodiment 3.

[0048] A cooling fan 81 is provided with a cut-out portion A in the axial direction of a magnetic inter-pole portion where a permanent magnet 10 is not inserted.

[0049] According to the present embodiment, cooling performance is improved by enlarging the external diameter of the fan to increase the amount of airflow. However, when the cooling fan 81 blocks the magnetic inter-pole portion where the permanent magnet 10 is not inserted, the cooling air W12 is blocked, reducing the amount of airflow. The cooling air W12 is not blocked by the provision of the cut-out portion A. This reduces pressure loss in an air path, improves the cooling performance of a field winding, and enhances output. The same cut-out portion A is provided in a cooling fan 82, thereby preventing the cooling air W22 from being blocked and achieving the same effects.

[0050] Embodiment 4

[0051] Fig. 9 is an overview view showing a part of interest of a rotor in a rotating electrical machine according to an embodiment 4.

[0052] The external diameter of a cooling fan 81 is smaller than the radial spacing of a magnetic inter-pole portion where a permanent magnet 10 is inserted. More specifically, the outermost diameter DI of the cooling fan 81 is smaller than the innermost diameter D2 of an insertion portion of the permanent magnet 10.

[0053] According to this embodiment, pressure loss in an air path is reduced without blocking the cooling air W12 by reducing the external diameter of the fan. Furthermore, component cost or weight can be reduced. In addition, noise can be reduced. Similarly, with regard to a cooling fan 82, by using the same configuration, the cooling air W22 is not blocked and the same effects can be achieved.

[0054] Embodiment 5

[0055] The [Fig. 10] is an overview view showing a part of interest of a rotor in a rotating electrical machine according to an embodiment 5.

[0056] The angle of inclination of a claw of a first claw-shaped magnetic pole portion 911 on side C (the lead side in a direction of rotation) where a permanent magnet 10 is not provided is greater than that on side B (the recoil side in the direction of rotation) where the permanent magnet is provided. More specifically, with respect to the two circumferential surfaces in the axial direction of the shaft that form the claw-shaped magnetic pole portion 911 on the side where a power supply unit 300 is not arranged, the angle of inclination C on the lead side in the direction of rotation that is formed by one of the two circumferential surfaces and a plane formed by the normal direction of the outermost circumferential side surface of the claw-shaped magnetic pole portion claw 911, is greater than the angle of inclination B of the recoil side in the direction of rotation which is formed by the other of the two circumferential surfaces and a plane formed by the normal direction of the outermost circumferential side surface of the claw-shaped magnetic pole portion 911.

[0057] According to the present embodiment, an axial component of a PI direction in which the first portion of the claw-shaped magnetic pole 911 pushes adjacent air is augmented to promote a flow of cooling air W12, thereby increasing the amount of airflow, improving cooling performance, and enhancing output.

[0058] Embodiment 6

[0059] The [Fig. 11] is a cross-sectional view of a part of interest of a rotating electrical machine according to an embodiment 6.

[0060] A power supply unit 300 is cooled by a liquid refrigerant supplied to a liquid refrigerant line 15 provided in the power supply unit 300.

[0061] According to the present embodiment, the power supply unit 300 does not need to be cooled by cooling air from the rotation of a cooling fan 82, and thus a cooling fan 82 can be reduced and / or eliminated, thereby reducing component cost and further reducing the axial height of an electric motor. The cooling fan 82 is not provided in the embodiment of [Fig. 11].

[0062] In this case, the amount of airflow of the cooling air W2 is even smaller than that of the cooling air W1 and / or becomes zero. In this situation, when a permanent magnet 10 is arranged in a position where the cooling air W12 is produced, only the cooling air W11 flows towards the electric motor; thus, cooling efficiency is reduced and performance is reduced. Consequently, the permanent magnet 10 needs to be arranged adjacent to the leading side in the direction of rotation of claw-shaped magnetic pole portions of a second magnetic pole.

[0063] The present application describes various examples of embodiments and examples; however, various features, aspects, and functions described in one or a plurality of embodiments are not limited to specific embodiments, but may be applied to embodiments individually or in various combinations thereof.

[0064] Consequently, a very large number of modified examples not given by way of example are presumed to exist within the technical ranges disclosed in the memorandum of this application. By way of example, these include: a case in which at least one constituent element is modified; a case in which one is added; or a case in which it is removed; and a case in which at least one constituent element is extracted to combine with constituent elements of other embodiments.

Claims

1. Demands Rotating electric machine comprising: a rotor (6) configured to include magnetic poles (91, 92) in which a plurality of claw-shaped magnetic pole portions (911, 921) are provided on the outer circumference thereof, a field winding (5) wound around the magnetic poles (91, 92), and a shaft (4) which is in rotation as a single unit with the magnetic poles (91, 92) and the field winding (5); a stator (3) configured to include a stator core (31) arranged in a face-to-face relationship with the outer circumference of the magnetic poles (91, 92), and a stator winding (32) wound around the stator core (31); a permanent magnet (10) configured to be disposed between the claw-shaped magnetic pole portions (911, 921) adjacent to the magnetic poles (91, 92), and to be magnetized in a direction reducing a leaky magnetic flux between the claw-shaped magnetic pole portions (911, 921); a cooling fan (81) configured to be provided on at least one of the axial sides of the shaft (4) in the magnetic poles (91, 92), and to cool the field winding (5) and the permanent magnet (10); supports (1,2) configured to contain the stator (3) and the rotor (6), and to support the rotating shaft (4); and a power supply unit (300) configured to supply power to the stator winding (32) or the field winding (5), in which the power supply unit (300) is configured to be fixed on the axial side of the shaft (4) of the support (2); and the permanent magnet (10) is configured to be arranged on the lead side in the direction of rotation of the claw-shaped magnetic pole portion (921) of the magnetic pole (92) on the side where the power supply unit (300) is provided, the rotating electrical machine being characterized in that, with respect to the two circumferential surfaces in the axial direction of the shaft (4) which form the claw-shaped magnetic pole portions (911) on the side where the power supply unit (300) is not arranged, an angle of inclination (C) of the leading side in the direction of rotation which is formed by one of the two circumferential surfaces and a plane formed by the normal direction of the outermost circumferential side surface of the claw-shaped magnetic pole portion (911), is configured to be greater than an angle of inclination (B) of the recoiling side in the direction of rotation which is formed by the other of the two circumferential surfaces and a plane formed by the normal direction of the outermost circumferential side surface of the claw-shaped magnetic pole portion (911).

2. Rotating electric machine according to claim 1, wherein a magnetic inter-pole portion where the permanent magnet (10) is disposed and a magnetic inter-pole portion where the permanent magnet (10) is not disposed are configured to be arranged alternately in the direction of rotation.

3. Rotating electrical machine according to claim 1 or claim 2, wherein the cooling fan (81) is configured to be provided with a cut-out portion (A) on the axial side of the magnetic inter-pole portion where the permanent magnet (10) is not disposed.

4. Rotating electrical machine according to claim 1 or claim 2, wherein the outermost diameter of the cooling fan (81) is configured to be smaller than a spacing of the magnetic inter-pole portion where the permanent magnet (10) is inserted.

5. Rotating electric machine according to any one of claims 1 to claim 4, wherein the power supply unit (300) is configured to be cooled by a liquid refrigerant supplied to a liquid refrigerant line (15) provided in the power supply unit (300).

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