Multi-phase motor

Abstract

The purpose of the present invention is to reduce the size of a multiphase motor. An electric motor (10) is provided with: a stator section (21) having a cylindrical stator core (21A) and a plurality of phase coils (21B, 21C, 21D); a housing (11) that accommodates the stator part (21); and a switching unit (31) that switches the connection state of the coil unit group (C) in each of the coils (21B, 21C, 21D). The switching unit (31) has a plurality of relay switches (31B). The relay switch (31B) is disposed in a space (S1) between the outer peripheral surface of the stator part (21) and the inner peripheral surface of the housing (11).

Description

Technical Field

[0001] The present invention relates to multi-phase electric motors. Background Art

[0002] Patent Document 1 discloses a driving device having a structure in which an open end of a motor case is closed by a frame member formed of a metal having good thermal conductivity such as aluminum. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-34205 Summary of the invention Problems to be solved by the invention

[0004] The driving device of Patent Document 1 is provided with a circuit substrate on the side opposite to the stator via a frame member having good thermal conductivity. A plurality of SW elements are mounted on the circuit substrate. These SW elements are close to the frame member via a heat dissipation gel. However, when the circuit substrate and SW elements are arranged in this way, the axial dimension of the shaft in the driving device tends to become larger.

[0005] An object of the present invention is to provide a more compact multi-phase motor. Means for solving problems

[0006] The multi-phase motor of the present invention comprises: A stator part having a cylindrical stator core and a plurality of phase coils; a housing for housing the stator; and a switching unit for switching a connection state of a plurality of coil units in each of the coils; The switching unit includes a plurality of relay switches. At least one of the relay switches is arranged between the outer peripheral surface of the stator portion and the inner peripheral surface of the housing. Effects of the Invention

[0007] The present invention can make the multi-phase motor more compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is an exploded perspective view of the electric motor according to the first embodiment. Figure 2 This is an end view of the stator. Figure 3 It is a side cross-sectional view showing a state where the stator portion is accommodated in the housing. Figure 4 It is a three-dimensional diagram of a switching unit. Figure 5 It is a side cross-sectional view showing a state where the stator unit and the switching unit are accommodated in the housing. Figure 6 This is a circuit diagram showing an example of connection between the coil portion of the U phase and the relay switch. DETAILED DESCRIPTION

[0009] The following are examples of embodiments of the present invention. The features of [1] to [5] described below may be combined arbitrarily within the range of non-contradiction.

[0010] The multi-phase motor of the present invention, [1] A stator unit having a cylindrical stator core and a plurality of phase coils; a housing for housing the stator unit; and a switching unit for switching the connection state of the plurality of coil units in each coil. The switching unit has a plurality of relay switches. At least one of the relay switches is disposed between the outer peripheral surface of the stator unit and the inner peripheral surface of the housing.

[0011] The multi-phase motor of [1] can dissipate heat from the relay switch easily because the relay switch can be arranged near the inner peripheral surface of the housing. Also, the axial dimension of the motor can be suppressed because the relay switch is arranged between the stator and the housing.

[0012] [2] In the multi-phase motor of [1] above, the switching unit can have a ring-shaped circuit substrate that holds a plurality of relay switches. A space is formed in the housing that is closer to one end of the housing than one end of the stator unit in a predetermined direction and is surrounded by the housing, and the circuit substrate of the switching unit can be arranged in the space.

[0013] In the multi-phase motor of [2] above, the circuit board is arranged in the space formed in the casing, so that the space can be effectively utilized.

[0014] [3] In the multi-phase motor of [1] or [2] above, each relay switch can be a semiconductor relay.

[0015] The multi-phase motor of the above-mentioned [3] can easily miniaturize the relay switch, and thus can be easily arranged in a narrow space.

[0016] [4] In the multi-phase motor of [1] or [2] above, at least one of the relay switches can be arranged between the outer peripheral surface of the stator portion and the inner peripheral surface of the housing and in contact with the inner peripheral surface of the housing.

[0017] The multi-phase motor of the above-mentioned [4] can be easily constructed with a structure that reliably releases the heat generated by the relay switch to the housing.

[0018] [5] In the multi-phase motor of [2] above, at least one of the relay switches can protrude from the circuit board and be arranged between the outer peripheral surface of the stator and the inner peripheral surface of the housing. The ends of each coil part can be fixed to the circuit board.

[0019] The multi-phase motor of the above-mentioned [5] can maintain the positions of the relay switch and the circuit board by fixing the ends of the coil portion to the circuit board that holds the relay switch.

[0020] <Implementation Method 1> [Structure of the motor] The motor 10 of the first embodiment is a multi-phase motor using a multi-phase AC power supply. Figure 1 As shown, the electric motor 10 includes a housing 11, a stator unit 21, and a switching unit 31. Furthermore, the electric motor 10 is provided with a rotor unit (not shown) and an end surface cover (not shown).

[0021] The housing 11 is made of metal, for example, and has a cylindrical shape with both ends in the axial direction opened. The outer peripheral surface of the housing 11 is formed with irregularities over the entire circumference. The housing 11 accommodates the stator unit 21 and the switching unit 31 .

[0022] [Structure of stator part] The stator part 21 is fixed to the inner side of the housing 11. Figure 2 As shown, the stator unit 21 includes a stator core 21A and a plurality of coils 21B, 21C, and 21D. The stator core 21A is made of a cylindrical metal having conductivity.

[0023] The plurality of coils 21B, 21C, and 21D are configured as three-phase segment coils. The coil 21B corresponds to the first phase (U phase), the coil 21C corresponds to the second phase (V phase), and the coil 21D corresponds to the third phase (W phase). The coil 21B of the first phase (U phase) has coil parts 1U, 3U, 2U, and 4U. The coil 21C of the second phase (V phase) has coil parts 1V, 3V, 2V, and 4V. The coil 21D of the third phase (W phase) has coil parts 1W, 3W, 2W, and 4W.

[0024] The coil parts 1U, 3U, 2U, 4U of the first phase (U phase), the coil parts 1V, 3V, 2V, 4V of the second phase (V phase), and the coil parts 1W, 3W, 2W, 4W of the third phase (W phase) are each in the form of a spiral (coil) wound with electric wires forming themselves.

[0025] The coil parts 1U, 3U, 2U, 4U, 1V, 3V, 2V, 4V, 1W, 3W, 2W, 4W (hereinafter referred to as coil part group C) are arranged in a circular ring along the inner circumference of the stator core 21A. Specifically, the coil part group C is arranged so that the axis perpendicular to the winding direction is perpendicular to the center line of the stator core 21A.

[0026] Each coil portion 1U, 3U, 2U, 4U, 1V, 3V, 2V, 4V, 1W, 3W, 2W, 4W has a pair of terminal portions T (i.e., the ends of the coil portion group C). The terminal portions T of the coil portion group C arranged along the inner circumference of the stator core 21A are led out to one side in the direction of the central axis of the stator core 21A. These terminal portions T are arranged on the outside (away from the center line) of the coil portion group C. The stator core 21A of the stator portion 21 protrudes in a flange-like manner in a direction away from the center line relative to the annular coil portion group C (refer to Figure 1 ).

[0027] like Figure 3 As shown, the stator portion 21 formed in this way is accommodated in the housing 11 in a coaxial posture relative to the housing 11. The outer peripheral surface of the stator core 21A of the stator portion 21 contacts the inner peripheral surface of the housing 11. Thus, the stator portion 21 is fixed to the housing 11. A predetermined size is spaced between the coil portion group C and the inner peripheral surface of the housing 11 to form a circular ring-shaped space S1. In the housing 11, the terminal portion T of the coil portion group C protrudes from the coil portion group C in the direction extending from the center line. In the housing 11, the area where the terminal portion T protruding from the coil portion group C is arranged is the space S2. The space S2 is disc-shaped and is a space surrounded by the housing 11 in a manner along one end of the stator portion 21. In other words, the space S2 is a space in the housing 11 that is closer to one end side of the housing 11 than one end of the stator portion 21 in the direction of the central axis (predetermined direction) of the stator portion 21 and is surrounded by the housing 11.

[0028] [Structure of the switching unit] like Figure 4 As shown, the switching unit 31 includes a circuit board 31A and a plurality of relay switches 31B. The circuit board 31A is formed of, for example, glass epoxy resin. The circuit board 31A is annular. A conductive circuit pattern (not shown) is formed on one surface P1 of the circuit board 31A.

[0029] The plurality of relay switches 31B are configured as semiconductor relays. The semiconductor relays are configured, for example, by MOSFET, GaNFET, IGBT, bipolar transistor, etc. Each relay switch 31B has a switch body 31C having a rectangular flat plate shape and three electrodes 31D extending from one end edge of the switch body 31C. Each relay switch 31B is configured to switch between an on state and an off state according to an on instruction or an off instruction of a control signal from a control device (not shown). Each relay switch 31B becomes an on state that allows power to be supplied to itself according to an on instruction from the control device, and becomes an off state that cuts off power to itself according to an off instruction from the control device.

[0030] The three electrodes 31D of each relay switch 31B are fixed to the circuit pattern formed on the board surface P1 of one side of the circuit substrate 31A by solder. In this way, the circuit substrate 31A holds a plurality of relay switches 31B. Each relay switch 31B is arranged so as to protrude from the board surface P1 of one side of the circuit substrate 31A. Specifically, the board surface P2 of the switch body 31C of each relay switch 31B is oriented orthogonal to the board surface P1 of the circuit substrate 31A and along the outer edge of the circuit substrate 31A. Each relay switch 31B is formed in such a posture relative to the circuit substrate 31A and is arranged near the outer edge of the circuit substrate 31A.

[0031] The switching unit 31 formed in this way is accommodated in the spaces S1 and S2. Figure 5 As shown, the plate surface P1 of one side of the circuit substrate 31A is opposed to the protruding side of the terminal portion T of the stator portion 21, and each relay switch 31B is oriented to face the coil portion group C. In addition, the circuit substrate 31A is arranged in the space S2, and each relay switch 31B is arranged in the space S1 between the outer peripheral surface of the stator portion 21 and the inner peripheral surface of the housing 11 and connected to the space S2. Each relay switch 31B is in contact with the inner peripheral surface of the housing 11 via heat dissipation grease G or the like. In addition, a rotor portion not shown is arranged in the stator portion 21, and both ends of the opening of the housing 11 are covered with end surface covers not shown.

[0032] The terminal end T of the coil assembly C is fixed to the circuit pattern of the circuit board 31A accommodated in the space S2 by soldering. The coil assembly C and each relay switch 31B are formed via the circuit board 31A, for example. Figure 6 Specifically, the three relay switches 31B are electrically connected to the first coil portion C1 formed by the coil portions 1U and 3U being electrically connected in series, and the second coil portion C2 formed by the coil portions 2U and 4U being electrically connected in series. Each relay switch 31B is provided between one end of the first coil portion C1 and one end of the second coil portion C2, between the other end of the first coil portion C1 and the other end of the second coil portion C2, and between the other end of the first coil portion C1 and one end of the second coil portion C2.

[0033] In the present invention, the so-called "electrical connection" is expected to be a structure in which the connection objects are connected in a state of mutual conduction (a state in which current flows) in a manner that the potentials of both connection objects are equal. However, it is not limited to this structure. For example, the so-called "electrical connection" may also be a structure in which the connection objects are connected in a state in which an electrical component is interposed between the two connection objects and the two connection objects are able to conduct.

[0034] Figure 61 is a diagram illustrating the structure of the coil parts 1U, 3U, 2U, and 4U of the first phase (U phase). The coil parts 1V, 3V, 2V, and 4V of the second phase (V phase) and the coil parts 1W, 3W, 2W, and 4W of the third phase (W phase) also have the same structure. The other end of the second coil part C2 of each phase (the other end of the coil part 4U, 4V, and 4W) is electrically connected to the neutral part, i.e., the busbar, which is not shown in the figure. One end of the first coil part C1 of each phase (one end of the coil part 1U, 1V, and 1W) is electrically connected to the inverter, which is not shown in the figure. In the first embodiment, three relay switches 31B are provided in each phase. Therefore, in the first embodiment, a total of nine relay switches 31B are used.

[0035] For example, the control device (not shown) is used to disconnect the relay switch 31B between one end of the first coil portion C1 and one end of the second coil portion C2 and between the other end of the first coil portion C1 and the other end of the second coil portion C2. At the same time, the relay switch 31B between the other end of the first coil portion C1 and one end of the second coil portion C2 is connected, so that the first coil portion C1 and the second coil portion C2 can be connected in series.

[0036] In contrast, the relay switch 31B between one end of the first coil portion C1 and one end of the second coil portion C2 and between the other end of the first coil portion C1 and the other end of the second coil portion C2 is turned on. At the same time, the relay switch 31B between the other end of the first coil portion C1 and one end of the second coil portion C2 is turned off, so that the first coil portion C1 and the second coil portion C2 can be connected in parallel. In this way, the connection state of the coil portion group C is switched between the series state and the parallel state in the coils 21B, 21C, and 21D by the switching unit 31, so that the characteristics of the motor 10 can be changed.

[0037] Next, the effects of this structure are exemplified. The electric motor 10 includes: a stator portion 21 having a cylindrical stator core 21A and coils 21B, 21C, and 21D of a plurality of phases; a housing 11 that accommodates the stator portion 21; and a switching portion 31 that switches the connection state of the coil portion group C in each of the coils 21B, 21C, and 21D. The switching portion 31 includes a plurality of relay switches 31B. The relay switch 31B is disposed in a space S1 between the outer peripheral surface of the stator portion 21 and the inner peripheral surface of the housing 11. According to this structure, since the relay switch 31B can be disposed near the inner peripheral surface of the housing 11, heat dissipation of the relay switch 31B becomes easy. At the same time, since the relay switch 31B is configured to be disposed between the stator portion 21 and the housing 11, the size of the electric motor 10 in the center line direction can be suppressed.

[0038] The switching unit 31 includes a circular circuit substrate 31A that holds a plurality of relay switches 31B. A space S2 is formed in the housing 11 that is closer to one end of the housing 11 than one end of the stator 21 in the central axis direction of the stator 21 and is surrounded by the housing 11, and the circuit substrate 31A of the switching unit 31 is disposed in the space S2. According to this structure, since the circuit substrate 31A is disposed in the space S2 formed in the housing 11, the space S2 can be effectively used.

[0039] In the electric motor 10, each relay switch 31B is a semiconductor relay. According to this structure, the relay switch 31B can be easily miniaturized, and thus can be easily arranged in a narrow space S1.

[0040] In the motor 10, the relay switch 31B is disposed between the outer peripheral surface of the stator portion 21 and the inner peripheral surface of the housing 11, and contacts the inner peripheral surface of the housing 11 via the heat dissipating grease G. This structure can easily construct a structure that reliably releases heat generated by the relay switch 31B to the housing 11.

[0041] In the motor 10, the relay switch 31B protrudes from the circuit substrate 31A and is arranged between the outer peripheral surface of the stator part 21 and the inner peripheral surface of the housing 11. The terminal portion T of each coil portion group C is fixed to the circuit substrate 31A. According to this structure, by fixing the terminal portion T of the coil portion group C to the circuit substrate 31A holding the relay switch 31B, the position of the relay switch 31B and the circuit substrate 31A can be maintained. <Other Implementation Methods> The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed this time, but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0043] Unlike the first embodiment, the entire relay switch need not be disposed between the stator portion and the case, and a part of the relay switch may be disposed between the stator portion and the case.

[0044] Unlike the first embodiment, the entire relay switch need not be in contact with the inner peripheral surface of the housing via the heat dissipation grease. Instead, a portion of the relay switch may be in contact with the inner peripheral surface of the housing via the heat dissipation grease, and the other portion may be in direct contact with the inner peripheral surface of the housing.

[0045] Unlike the first embodiment, the entire relay switch need not be fixed to the circuit board, and a part of the relay switch may be fixed to the circuit board, and the other part may be fixed to another location.

[0046] Unlike the first embodiment, the circuit substrate is not limited to an annular shape, but may be a polygonal annular shape, or may be a structure in which a plurality of arc-shaped circuit substrates are arranged. In addition, a part of the annular shape may be cut away (eg, a C-shape).

[0047] In the first embodiment, each coil of the U phase, the V phase, and the W phase has a structure with four coil parts, but the number of coil parts is not limited to this number.

[0048] The number of relay switches is not limited to the number disclosed in Embodiment 1. In addition, the arrangement position of the relay switch with respect to the circuit board is not limited to the position disclosed in Embodiment 1. Description of Reference Numerals

[0049] 1U, 1V, 1W, 2U, 2V, 2W, 3U, 3V, 3W, 4U, 4V, 4W: Coil 10: Electric motor (multi-phase motor) 11: Shell 21: Stator 21A: stator core 21B, 21C, 21D: Coil 31: Switching Department 31A: Circuit board 31B: Relay switch 31C: Switch body 31D: Electrode C: Coil assembly C1: 1st coil C2: Second coil G: Heat dissipation grease P1: Circuit board surface P2: Switch body panel S1, S2: Space T: Terminal (end of coil)

Claims

1. A polyphase motor, comprising: A stator portion having a cylindrical stator core and coils of multiple phases; A housing that houses the stator portion; and A switching portion that switches the connection states of multiple coil portions in each of the coils, The switching portion has multiple relay switches, At least any one of the relay switches is disposed between the outer peripheral surface of the stator portion and the inner peripheral surface of the housing.

2. The polyphase motor according to claim 1, Wherein, The switching portion has an annular circuit board that holds the multiple relay switches, A space is formed in the housing on the end side of the housing relative to one end of the stator portion in a predetermined direction and surrounded by the housing, The circuit board is disposed in the space.

3. The polyphase motor according to claim 1 or claim 2, Wherein, Each of the relay switches is a semiconductor relay.

4. The polyphase motor according to claim 1 or claim 2, Wherein, At least any one of the relay switches is disposed between the outer peripheral surface of the stator portion and the inner peripheral surface of the housing and contacts the inner peripheral surface of the housing.

5. The polyphase motor according to claim 2, Wherein, At least any one of the relay switches protrudes from the circuit board and is disposed between the outer peripheral surface of the stator portion and the inner peripheral surface of the housing, The ends of each of the coil portions are fixed to the circuit board.

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