Bus bar guide, bus bar assembly using the same, and electric motor

Abstract

A busbar guide is provided to secure a busbar that connects multiple coils in an electric motor. The busbar includes a plate-shaped conductor having a first surface and a second surface continuous with the first surface. The busbar guide is constructed by arranging multiple busbar guide segments, each made of an insulator, in a ring shape. Each of the multiple busbar guide segments has a groove that holds the first surface of the busbar and positions the busbar.

Description

Technical Field

[0001] The present invention relates to a bus bar guide, a bus bar assembly using the bus bar guide, and an electric motor. Background Art

[0002] Conventionally, a structure using a plate-shaped bus bar to connect a plurality of coils provided in an electric motor is widely known.

[0003] For example, Patent Document 1 discloses a structure in which a plurality of grooves are provided in an annular insulator provided on an upper portion of a stator core, and bus bars are fitted into and held in the grooves.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-090404 Summary of the Invention

[0007] However, in conventional structures, such as that disclosed in Patent Document 1, the insulator that holds the busbars is integrally formed as a single component. Therefore, it is difficult to accommodate variations in the shape of the multiple busbars or the position of the terminals of the coils, thereby arranging the components in the desired locations. Furthermore, variations in the shape of the insulator itself can sometimes cause positional shifts between the components, making it difficult to reliably connect the coils.

[0008] The present invention has been made in view of the above-mentioned problems and has an object to provide a bus bar guide that can absorb shape and arrangement variations of components and reliably connect coils, a bus bar assembly using the bus bar guide, and an electric motor.

[0009] In order to achieve the above-mentioned purpose, the bus bar guide of the present invention is used to fix a bus bar that connects multiple coils provided in an electric motor, wherein the bus bar includes a plate-shaped conductor, the plate-shaped conductor having a pair of first surfaces extending radially and opposite to each other and a pair of second surfaces extending axially and opposite to each other continuous with the first surfaces, the bus bar guide is formed by arranging multiple bus bar guide pieces each composed of an insulator in a ring shape, and each of the multiple bus bar guide pieces is provided with a groove portion, which is used to hold the first surface of the bus bar and position the bus bar.

[0010] The bus bar assembly of the present invention includes at least the bus bar guide and a plurality of bus bars respectively arranged in the plurality of grooves provided on the upper surface of the bus bar guide.

[0011] The electric motor of the present invention comprises at least: a rotor having an output shaft at its axis; a stator arranged at a predetermined interval from the rotor; and the bus bar assembly mounted on the upper portion of the stator, wherein the stator comprises at least: an annular yoke; a plurality of teeth connected to the inner circumference of the yoke at predetermined intervals; and a plurality of coils mounted on each of the plurality of teeth, two of the plurality of coils being electrically connected via one of the plurality of bus bars.

[0012] The busbar guide according to the present invention can accommodate busbar shape deviations, making it easier to position the busbars within the busbar guide. The busbar assembly according to the present invention can accommodate busbar shape deviations, making it easier to position multiple busbars within the busbar guide. The electric motor according to the present invention can easily position multiple busbars within the busbar guide. Furthermore, since multiple busbars are positioned and positioned within the busbar guide, the motor assembly process can be simplified, thereby reducing assembly costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a plan view of the electric motor according to the embodiment of the present invention.

[0014] Figure 2 yes Figure 1 Cross-sectional view at line II-II.

[0015] Figure 3 is a top view of the bus bar guide.

[0016] Figure 4A It is a plan view of the bus bar guide when the bus bar is arranged in the groove portion.

[0017] Figure 4B yes Figure 4A A perspective view of the bus bar guide is shown.

[0018] Figure 5A This is a top view of the busbar.

[0019] Figure 5B yes Figure 5A Schematic cross-sectional view of the VB-VB line.

[0020] Figure 5C yes Figure 5A An enlarged view of the end of a bus bar is shown.

[0021] Figure 6A It is an enlarged top view of the groove portion.

[0022] Figure 6B yes Figure 6ASchematic cross-sectional view at the VIB-VIB line.

[0023] Figure 7A is an enlarged top view of the gap.

[0024] Figure 7B This is a schematic diagram of the vicinity of the gap as viewed from the radial direction.

[0025] Figure 8A This is a perspective view of a bus bar according to Modification 1.

[0026] Figure 8B This is an enlarged schematic diagram of the connection portion between the bus bar and the lead portion in Modification 1.

[0027] Figure 9 This is a plan view of a bus bar according to Modification 2. DETAILED DESCRIPTION

[0028] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present invention, its applications, or its uses.

[0029] (Implementation Method)

[0030] [Structure of the motor]

[0031] Figure 1 It is a plan view of the electric motor according to the embodiment of the present invention. Figure 2 yes Figure 1 In the following description, the radial direction of the motor 1000 is referred to as the “radial direction”, the peripheral direction is referred to as the “circumferential direction”, and the axial direction of the output shaft 210 of the motor 1000 is referred to as the “axial direction”. Figure 1 The direction perpendicular to the paper in the drawing) is called the "axial direction". In the radial direction, there is a case where the axial center side of the motor 1000 is called the radial inner side, and the outer peripheral side is called the radial outer side. The outer peripheral direction of the motor 1000 is the same as the outer peripheral direction of the bus bar guide 60 described later. Therefore, there is a case where the outer peripheral direction of the bus bar guide 60 is also called the "circumferential direction". Similarly, the radial direction of the motor 1000 is the same as the radial direction of the bus bar guide 60. Therefore, there is a case where the radial direction of the bus bar guide 60 is also called the "circumferential direction". In the motor 1000, there is a case where the side where the bus bar guide 60 is provided is called the upper or upper side, and the side along the axial direction and opposite to it is called the lower or lower side. In Figure 2 , the lead wire portion 41 of the coil 40 is omitted from the figure. In addition, the axis of the motor 1000 and the axis of the output shaft 210 are aligned when viewed from the axial direction.

[0032] The motor 1000 includes a stator 100, a rotor 200, and a motor housing 400. The motor 1000 also includes components other than the above components, such as bearings for supporting an output shaft, etc. However, these components are omitted for ease of illustration.

[0033] The stator 100 includes an annular yoke 20, a plurality of teeth 10, slots 30, and coils 40. The teeth 10 are connected to the inner circumference of the yoke 20 and are arranged at equal intervals along the inner circumference. Slots 30 are provided between circumferentially adjacent teeth 10. The coils 40 are accommodated within the slots 30. The stator 100 is spaced apart from the rotor 200 and disposed radially outward of the rotor 200.

[0034] The teeth 10 and the yoke 20 are each formed by, for example, laminating electromagnetic steel sheets containing silicon or the like and then performing a punching process. The coil 40 is a component formed by spirally winding a conductive wire composed of copper or the like having a quadrilateral cross-section. The coil 40 has lead portions 41 at both ends. The coil 40 is mounted on each of the multiple teeth 10 via an insulator (not shown) and is accommodated in the slot 30. In addition, although not shown, an insulating coating is formed on the surface of the conductive wire constituting the coil 40. The busbar 50 is connected to the front end of the lead portion 41 by welding or the like.

[0035] In the present embodiment, the coils may be referred to as coils U1 to U4 , V1 to V4 , and W1 to W4 , respectively, depending on the phase of the current flowing through the coil 40 .

[0036] The bus bar assembly 300 includes a bus bar guide 60 and a plurality of bus bars 50. The bus bar guide 60 is formed by arranging a plurality of bus bar guide pieces 60a to 60k in the circumferential direction (see FIG. Figure 3 The bus bar guide pieces 60a to 60k are each formed by molding a thermoplastic insulating resin. However, a thermosetting resin may also be used. The shape and function of the bus bar guide 60 will be described in detail later.

[0037] The busbar 50 is formed by bending a conductor made of a plate of copper or the like into a predetermined shape. An insulating coating (not shown) is formed on the surface of the busbar 50. However, the insulating coating is removed from the connection portion with the lead portion 41 of the coil 40. The busbar 50 functions as wiring for electrically connecting the circumferentially separated coils 40. For example, the coils U1 to U4 are connected in series via a plurality of busbars 50. The shape of the busbar 50 will be described later.

[0038] Rotor 200 includes an output shaft 210; a rotor core 220 with output shaft 210 at its center; and multiple magnets 230 embedded within rotor core 220. Rotor 200 includes multiple magnets 230, facing stator 100, with alternating north and south poles arranged along the circumference of the output shaft. The material, shape, and construction of magnets 230 can be modified appropriately depending on the output of motor 1000, for example. Rotor core 220 is formed, for example, by laminating electromagnetic steel sheets containing silicon or the like and then performing a punching process.

[0039] The motor housing 400 is a bottomed, cylindrical metal component. It houses the stator 100 and the rotor 200. If the motor housing 400 is made of a magnetic material such as iron, it can function as a yoke that forms a magnetic circuit. In this case, the yoke 20 can be omitted.

[0040] Coils U1 to U4, V1 to V4, and W1 to W4 are connected in series. Currents in the three phases (U, V, and W) with a phase difference of 120° electrical angle are supplied to coils U1 to U4, V1 to V4, and W1 to W4, respectively, exciting them. This generates a rotating magnetic field in stator 100. This rotating magnetic field interacts with the magnetic field generated by magnets 230 in rotor 200, generating torque. Consequently, output shaft 210 rotates, supported by bearings (not shown).

[0041] [Structure of Bus Bar Guide and Bus Bar]

[0042] Figure 3 is a top view of the bus bar guide. Figure 4A It is a plan view of the bus bar guide when the bus bar is arranged in the groove portion. Figure 4B yes Figure 4A In addition, for the sake of convenience, in Figure 4A 、 Figure 4B Only one bus bar 50 is shown in the figure.

[0043] Figure 5A This is a top view of the busbar. Figure 5B yes Figure 5A Schematic cross-sectional view of the VB-VB line. Figure 5C yes Figure 5A An enlarged view of the end of a bus bar is shown. Figure 6A It is an enlarged top view of the groove portion. Figure 6B yes Figure 6A Schematic cross-sectional view at the VIB-VIB line. Figure 7A is an enlarged top view of the gap. Figure 7B This is a schematic diagram of the gap vicinity viewed from the radial direction. Figure 7B It is from Figure 7A The arrows are shown in the direction of observation in the schematic diagram.

[0044] exist Figure 5A 、 Figure 5C In FIG, the lead wire portion 41 of the coil 40 is also shown. Figure 7A 、 Figure 7B In the figure, the bus bar 50 is omitted. In the bus bar guide 60, the surface on which the bus bar 50 is arranged is sometimes referred to as the upper surface of the bus bar guide 60, and the opposite surface is sometimes referred to as the lower surface of the bus bar guide 60.

[0045] like Figure 3 As shown, the bus bar guide 60 is composed of eleven bus bar guide segments 60a to 60k arranged circumferentially. Adjacent bus bar guide segments 60a and 60b are interlocked and connected via a fitting portion 64a. Adjacent bus bar guide segments 60c and 60d are interlocked and connected via a fitting portion 64b. Three adjacent bus bar guide segments 60d to 60f are interlocked and connected via a fitting portion 64c. Three adjacent bus bar guide segments 60g to 60i are interlocked and connected via a fitting portion 64c. Adjacent bus bar guide segments 60j and 60k are interlocked and connected via a fitting portion 64c. In the following description, the fitting portions 64a to 64c may be collectively referred to as the fitting portion 64.

[0046] Meanwhile, bus bar guide pieces 60a and 60c, and bus bar guide pieces 60b and 60c, are separated by gaps 63a. Bus bar guide pieces 60f and 60g are separated by gaps 63b. Bus bar guide pieces 60i and 60j are separated by gaps 63c. Bus bar guide pieces 60k and 60a are separated by gaps 63d. In other words, the bus bar guide 60 is divided into a plurality of sections in the circumferential direction by gaps 63a to 63d.

[0047] from Figure 3 It can be seen that the plurality of fitting portions 64c have the same shape. The shapes of the fitting portions 64a and 64b are different from each other and also from the shape of the fitting portion 64c.

[0048] Each of the bus bar guide pieces 60a to 60k is formed with a through hole 62 and a groove 61. The groove 61 is formed in one bus bar guide piece or across a plurality of bus bar guide pieces. Figure 3As shown, the bus bar 50 is arranged in the groove 61 formed only in one bus bar guide piece 60j, 60k, and 60a, and the bus bar 50 is connected to the connection line connected to the external power supply. The lead portion 41 of the coil 40 passes through the through hole 62 and is led out to the top of the bus bar guide 60. In this way, the lead portion 41 of the coil 40 is connected to the end 50a of the bus bar 50. Figure 4A 、 Figure 4B As shown, a groove portion 61 is formed on the upper surface of the bus bar guide 60 , and both end portions 50 a of the bus bar 50 are fitted into the groove portion 61 in a state where both end portions 50 a are bent.

[0049] The two ends 50a of the bus bar 50 are folded back in the same direction relative to the circumferential direction, with the leading ends positioned radially inward. The groove 61 also has a hairpin-shaped curved portion 61a to accommodate the folded-back ends 50a of the bus bar 50. The curved portion 61a is arranged to surround the through-hole 62 in a plan view.

[0050] Furthermore, if Figure 5A 、 Figure 5C As shown, with the busbar assembly 300 mounted on the stator 100, the lead portions 41 are sandwiched between the two end portions 50a of the busbar 50. The lead portions 41 and the busbar 50 are joined to each other by welding, fusion (thermal caulking), or the like. In this manner, the busbar 50 is inserted into each of the plurality of grooves 61, thereby positioning the through-holes 62 corresponding to the positions of the lead portions 41 and the busbar 50.

[0051] like Figure 5B As shown, the bus bar 50 has a pair of first surfaces 51 extending radially and facing each other, and a pair of second surfaces 52 extending axially and facing each other. The first surface 51 is continuous with the second surface 52 and is substantially perpendicular to the second surface 52. The shape of the bus bar 50 is set so that the width w2 of the second surface 52 is wider than the width w1 of the first surface 51. The bus bar 50 is inserted into the groove portion 61 (see FIG. 1 ) so that the first surface 51 abuts against the bottom surface of the groove portion 61. Figure 4A 、 Figure 4B ).

[0052] like Figure 6A 、 Figure 6B As shown, when the depth of the groove portion 61 is d1 and the width thereof is w3, the relationships shown in the following equations (1) and (2) hold between the aforementioned widths w1 and w2 and the depth d1 and width w3.

[0053] d1≤0.5×w2…(1)

[0054] w1<w3≤2×w1…(2)

[0055] like Figure 1As shown, when the bus bar guide 60 is mounted on the upper portion of the stator 100, a temperature detection sensor 70 is disposed inside each of the gaps 63a to 63d as viewed from the axial upper side. The temperature detection sensor 70 detects the temperature of the motor 1000, particularly the temperature of the coil 40. Figure 7A As shown, wiring 71 is connected to temperature sensor 70. The output signal of temperature sensor 70 is output to a motor control unit (not shown) via wiring 71, for example, to monitor the temperature of motor 1000. When the output signal of temperature sensor 70 exceeds a predetermined value, the motor control unit notifies the user of a temperature abnormality. Alternatively, the motor 1000 is stopped after the abnormality notification. For example, a thermistor or thermocouple is used as temperature sensor 70.

[0056] like Figure 7B As shown, a portion of the wiring 71 connected to the temperature detection sensor 70 located inside the gap 63d is covered by a step 65 provided on the lower surface of the bus bar guide 60. Figure 3 As shown, a hole 66 is formed radially outside the gap 63c. The hole 66 is provided for passing a linear member (not shown) therethrough. When a temperature detection sensor 70 is disposed inside the gap 63c, the linear member is used to secure a wiring 71 connected to the temperature detection sensor 70 to the bus bar guide 60 or the bus bar 50.

[0057] [Effects, etc.]

[0058] As described above, the bus bar guide 60 of this embodiment is provided to fix the bus bar 50 that connects the plurality of coils 40 provided in the motor 1000. The bus bar 50 includes a plate-shaped conductor having a first surface 51 and a second surface 52 continuous with the first surface 51.

[0059] The bus bar guide 60 is formed by arranging a plurality of bus bar guide pieces 60a to 60k, each made of an insulator, in a ring shape. Each of the plurality of bus bar guide pieces 60a to 60k has a groove 61 formed therein. The groove 61 is used to hold the first surface 51 of the bus bar 50 and to position the bus bar 50.

[0060] By configuring the bus bar guide 60 with a plurality of bus bar guide pieces 60a to 60k, it is possible to accommodate variations in the shape of the bus bar 50. This makes it easier to position the bus bar 50 on the bus bar guide 60. Furthermore, it is possible to accommodate positional variations in the lead wires 41 of the coil 40. Therefore, the bus bar 50 can be accurately positioned to match the position of the lead wires 41. Providing the grooves 61 on the upper surface of the bus bar guide 60 ensures that the bus bar 50 is securely held.

[0061] like Figure 5B As shown, when the width w1 of the first surface 51 of the bus bar 50 is narrower than the width w2 of the second surface 52, the bus bar 50 can be arranged in a so-called vertical position. This reduces the area required for the arrangement of the bus bar 50, thereby increasing the degree of freedom in the arrangement of the bus bar 50.

[0062] As shown in the formula (1), the depth d1 of the groove portion 61 is preferably equal to or less than half the width w2 of the second surface 52 of the bus bar 50 .

[0063] As a result, the surface area of ​​the busbar 50 exposed from the groove portion 61 can be increased. As a result, the busbar 50 can be held by the groove portion 61, and the heat dissipation area of ​​the busbar 50 can be ensured. Therefore, the cooling efficiency of the busbar 50 by air and other refrigerants can be improved. By efficiently cooling the busbar 50 through which a large current flows, the reduction in efficiency of the motor 1000 can be suppressed. In addition, the temperature rise of the coil 40 and the stator 100 can be suppressed, thereby stably driving the motor 1000. In addition, the depth d1 needs to be set to a value to which the busbar 50 does not shake due to vibration of the motor 1000, etc.

[0064] As shown in the formula (2), the width w3 of the groove portion 61 is preferably larger than the width w1 of the first surface 51 of the bus bar 50 and is preferably not more than twice the width w1.

[0065] This allows the bus bar 50 to be easily fitted into the groove portion 61 , and prevents the bus bar 50 from rattling due to vibration of the motor 1000 or the like.

[0066] The bus bar guide 60 is divided into a plurality of parts by the gaps 63a to 63d. In other words, the bus bar 50 includes at least one set of two bus bar guide pieces that are adjacent to each other and are spaced apart from each other in the circumferential direction.

[0067] By configuring the bus bar guide 60 in this manner, even if there are significant positional variations in the lead portion 41 or shape variations in the bus bar 50, these variations can be reliably absorbed. This allows the bus bar 50 to be easily positioned on the bus bar guide 60. Furthermore, the bus bar 50 can be accurately positioned to match the position of the lead portion 41.

[0068] The bus bar guide 60 includes a plurality of sets of two adjacent bus bar guide pieces. Each of at least one set of bus bar guide pieces has a fitting portion 64 formed therein for interfitting and connecting the pieces. For example, three adjacent bus bar guide pieces 60d to 60f are fitted and connected to each other via a fitting portion 64c.

[0069] By configuring the bus bar guide 60 in this manner, the bus bar guide 60 can ensure strength against vibrations, etc. When the groove 61 into which one bus bar 50 is inserted is formed across multiple bus bar guide pieces, these bus bar guide pieces are individually fitted and connected at the fitting portions 64. This can minimize positional deviation of the groove 61. As a result, the bus bar 50 can be stably held by the groove 61.

[0070] The shape of the interlocking portions 64 formed on each bus bar guide piece in one set of bus bar guide pieces can be the same as the shape of the interlocking portions 64 formed on each bus bar guide piece in another set of bus bar guide pieces. For example, three adjacent bus bar guide pieces 60d to 60f are interlocked and connected to each other via interlocking portions 64c of the same shape. Similarly, three adjacent bus bar guide pieces 60g to 60i are also interlocked and connected via interlocking portions 64c of the same shape.

[0071] By defining the shape of the fitting portion 64 in this manner, the number of combinations of bus bars 50 that can be connected to each other can be increased. Therefore, the degree of freedom in arranging the bus bar guide 60 can be increased.

[0072] The shape of the interlocking portion 64 formed on each busbar guide piece of one set of busbar guide pieces can also be different from the shape of the interlocking portion 64 formed on each busbar guide piece of another set of busbar guide pieces. For example, the adjacent busbar guide piece 60a and busbar guide piece 60b are interlocked and connected to each other via the interlocking portion 64a. On the other hand, the adjacent busbar guide piece 60c and busbar guide piece 60d are interlocked and connected to each other via the interlocking portion 64b having a shape different from the shape of the interlocking portion 64a. In addition, the adjacent busbar guide piece 60j and busbar guide piece 60k are interlocked and connected to each other via the interlocking portion 64c having a shape different from both the shape of the interlocking portion 64a and the shape of the interlocking portion 64b.

[0073] By defining the shape of the fitting portion 64 in this manner, the plurality of bus bar guide pieces 60a to 60k can be accurately arranged at predetermined positions.

[0074] The temperature detection sensor 70 is arranged inside at least one of the gaps 63a to 63d provided in the bus bar guide 60. In other words, in the bus bar guide 60, the temperature detection sensor 70 is arranged between two bus bar guide pieces arranged at a distance from each other in the circumferential direction.

[0075] Thus, it is possible to ensure an installation area for the temperature detection sensor 70 and to hold the temperature detection sensor 70 by the bus bar guide 60 .

[0076] At least one bus bar guide piece has a step 65 on its lower surface, which is opposite to the upper surface where the groove 61 is formed. Part of the wiring 71 connected to the temperature detection sensor 70 is covered by the step 65 .

[0077] This allows wiring 71 to be stably positioned within stator 100, which includes busbar assembly 300. Furthermore, even if wiring 71 is stretched, the portion covered by step 65 will not be significantly displaced. This prevents temperature sensor 70, connected to wiring 71, from shifting from its intended position. This allows accurate detection of the temperatures of motor 1000 and coil 40.

[0078] In this embodiment, the bus bar guide piece 60a has a step 65 on its lower surface, but a recess may be provided. Even in this case, the wiring 71 does not significantly shift, thereby preventing the temperature detection sensor 70 connected to the wiring 71 from deviating from a predetermined position.

[0079] Furthermore, each of the plurality of bus bar guide pieces 60 a to 60 k is provided with a through hole 62 for passing the lead wire portion 41 provided in the coil 40 .

[0080] Thus, the coil 40 and the bus bar 50 can be connected via the lead portion 41 .

[0081] Furthermore, the groove 61 also has the aforementioned curved portions 61a corresponding to the folded portions at both ends of the bus bar 50. Matching the positions of these curved portions 61a, through-holes 62 are provided in each of the bus bar guide pieces 60a to 60k. This allows the bus bar 50 to be positioned and arranged relative to the lead portion 41 of the coil 40, ensuring a secure connection between the two.

[0082] The bus bar assembly 300 of the present embodiment includes a bus bar guide 60 and a plurality of bus bars 50 , each of which is disposed in a plurality of grooves 61 provided on the upper surface of the bus bar guide 60 .

[0083] As described above, the bus bar guide 60 is constructed by arranging a plurality of bus bar guide segments 60a to 60k in a ring shape. Gaps 63a to 63d are provided circumferentially around the bus bar guide 60. This allows for accommodating shape variations in the bus bars 50. Consequently, the plurality of bus bars 50 can be easily arranged within the bus bar guide 60. This allows for accommodating positional variations in the leads 41 of the coils 40, allowing the plurality of bus bars 50 to be accurately positioned to match the positions of the leads 41 of the plurality of coils 40 arranged circumferentially.

[0084] The electric motor 1000 of the present embodiment includes at least a rotor 200 having an output shaft 210 at its axis, a stator 100 provided at a predetermined distance from the rotor 200 , and a bus bar assembly 300 attached to the upper portion of the stator 100 .

[0085] Stator 100 includes at least an annular yoke 20, a plurality of teeth 10 connected to the inner circumference of yoke 20 at predetermined intervals, and a plurality of coils 40 attached to respective teeth 10. Two coils of coils 40 are electrically connected via one bus bar 50 of a plurality of bus bars 50.

[0086] By configuring the motor 1000 in this manner, the two coils 40 spaced apart from each other in the circumferential direction can be connected via the bus bar 50. For example, a delta-connected motor or a star-connected motor can be easily realized.

[0087] Multiple bus bars 50 can be easily installed on the bus bar guide 60. Since multiple bus bars 50 are positioned and arranged on the bus bar guide 60, the connection between the bus bars 50 and the coils is facilitated. This simplifies the assembly process of the stator 100, and further simplifies the assembly process of the electric motor 1000, thereby reducing assembly costs.

[0088] The plurality of bus bars 50 are disposed in a plurality of grooves 61 formed in the upper surface of the bus bar guide 60. The coil 40 includes a lead portion 41 for connecting to the bus bar 50. The lead portion 41 passes through a through hole 62 formed in the bus bar guide 60 and is led upward from the bus bar guide 60. The lead portion 41 is electrically connected to the bus bar 50.

[0089] Thus, the bus bar guide 60 reliably insulates the portion of the coil 40 other than the lead portion 41 from the bus bar 50. Furthermore, the bus bar guide 60 is pre-positioned with the groove 61 and through-hole 62 formed therein. Thus, the lead portion 41 of the coil 40 and the bus bar 50 can be connected in a pre-positioned state.

[0090] Both ends 50a of the bus bar 50 are folded back. With the lead portion 41 sandwiched between the ends 50a of the bus bar 50, the lead portion 41 and the bus bar 50 are electrically connected.

[0091] By configuring busbar 50 in this manner, the contact area between busbar 50 and lead portion 41 can be increased. Consequently, an increase in resistance between busbar 50 and coil 40 can be suppressed. Furthermore, the mechanical strength of the connection between busbar 50 and lead portion 41 can be enhanced. Consequently, the reliability of motor 1000 during long-term use can be improved.

[0092] As described above, the bus bar guide 60 of the present embodiment is used to fix the bus bar 50 that connects the multiple coils 40 provided in the electric motor 1000, wherein the bus bar 50 includes a plate-shaped conductor having a pair of first surfaces 51 extending radially and opposite to each other and a pair of second surfaces 52 extending axially and opposite to each other, which are continuous with the first surfaces 51. The bus bar guide 60 is formed by arranging a plurality of bus bar guide pieces 60a to 60k, each of which is made of an insulator, in a ring shape. Each of the plurality of bus bar guide pieces 60a to 60k is provided with a groove 61, which is used to hold the first surface 51 of the bus bar 50 and position the bus bar 50.

[0093] This allows for accommodating shape variations of the bus bar 50 , making it possible to easily arrange the bus bar 50 on the bus bar guide 60 .

[0094] Furthermore, there may be at least one set of two bus bar guide pieces 60 a and 60 b that are adjacent to each other and are arranged at a distance from each other along the outer circumferential direction of the bus bar guide 60 .

[0095] Alternatively, a plurality of sets of two adjacent bus bar guide pieces 60a to 60d may be provided, and the fitting portions 64c for fitting and connecting the bus bar guide pieces 60a and 60b may be formed on each of at least one set.

[0096] Furthermore, the shape of the fitting portion 64c formed on each bus bar guide piece of one set of bus bar guide pieces 60a and 60b may be the same as the shape of the fitting portion 64c formed on each bus bar guide piece of the other set of bus bar guide pieces 60c and 60d.

[0097] Furthermore, the shape of the fitting portion 64c formed on each bus bar guide piece of one set of bus bar guide pieces 60a and 60b may be different from the shape of the fitting portion 64c formed on each bus bar guide piece of the other set of bus bar guide pieces 60c and 60d.

[0098] Furthermore, a sensor corresponding to the temperature detection sensor 70 may be disposed between two bus bar guide pieces 60 a and 60 b that are disposed at a distance from each other along the outer circumferential direction of the bus bar guide 60 .

[0099] In addition, preferably, at least one bus bar guide piece 60a is provided with a step 65 or a recess on the surface opposite to the surface having the groove 61, and at least a portion of the wiring 71 connected to the sensor corresponding to the temperature detection sensor 70 is covered by the step 65 or the recess.

[0100] In addition, it is preferable that the depth of the groove portion 61 is equal to or less than half the width of the second surface 52 of the bus bar 50 .

[0101] Furthermore, each of the plurality of bus bar guide pieces 60 a to 60 k may be provided with a through hole 62 for passing the lead wire portion 41 provided in the coil 40 .

[0102] It is preferable that the width of the first surface 51 is narrower than the width of the second surface 52 .

[0103] The bus bar assembly 300 of the present embodiment includes at least the bus bar guide 60 described above and a plurality of bus bars 50 disposed in a plurality of grooves 61 provided on the upper surface of the bus bar guide 60 .

[0104] This makes it possible to absorb shape variations of the bus bar 50 and easily arrange the plurality of bus bars 50 on the bus bar guide 60 .

[0105] In addition, the electric motor 1000 of this embodiment includes at least: a rotor 200 having an output shaft 210 at its axis; a stator 100, which is arranged at a predetermined interval from the rotor 200; and the above-mentioned bus bar assembly 300, which is installed on the upper part of the stator 100, and the stator 100 includes at least: an annular yoke 20; a plurality of teeth 10, which are connected to the inner circumference of the yoke 20 at predetermined intervals; and a plurality of coils 40, which are installed on each tooth of the plurality of teeth 10, and two coils 40 among the plurality of coils 40 are electrically connected via one bus bar 50 among the plurality of bus bars 50.

[0106] This makes it possible to easily install the plurality of bus bars 50 on the bus bar guide 60. Furthermore, since the plurality of bus bars 50 are positioned and arranged on the bus bar guide 60, the assembly process of the electric motor 1000 can be simplified, thereby reducing assembly costs.

[0107] In addition, it is preferred that the plurality of bus bars 50 are respectively arranged in the plurality of grooves 61 provided on the upper surface of the bus bar guide 60, and the coil 40 has a lead portion 41 for connecting to the bus bar 50. The lead portion 41 passes through a through hole 62 provided in the bus bar guide 60 and is led out to the top of the bus bar guide 60 and is electrically connected to the bus bar 50.

[0108] In addition, it is preferable that both ends of the bus bar are folded back, and the lead portion 41 and the bus bar 50 are electrically connected in a state in which the lead portion 41 is sandwiched by the end portions of the bus bar 50 .

[0109] <Variation 1>

[0110] Figure 8A This is a perspective view of a bus bar according to Modification 1. Figure 8B: is an enlarged schematic diagram of the connection portion between the bus bar and the lead portion of Modification 1. Figure 8A 、 Figure 8B In the embodiment, the same parts are marked with the same reference numerals and detailed descriptions are omitted.

[0111] Figure 8A 、 Figure 8B The bus bar 50 shown is connected to Figure 5A The bus bar 50 shown is different in that a projection 50b is formed at each of the two end portions 50a, extending upward from the first surface 51. When the bus bar 50 and the lead portion 41 are connected, the tip of the lead portion 41 is supported by the projection 50b.

[0112] According to this modified example, the lead portion 41 can be reliably held by the end portion 50a of the bus bar 50. If the bus bar 50 is not provided with the protrusion 50b, if there is a variation in the length of the lead portion 41, the tip of the lead portion 41 may be located below the first surface 51 on the upper side of the bus bar 50. In this case, the contact area between the lead portion 41 and the bus bar 50 may not be sufficient, and the reliability of the connection may be reduced.

[0113] On the other hand, according to this variation, a protrusion 50b is provided extending upward from the first surface 51 of the bus bar 50, and the lead portion 41 is supported by the protrusion 50b. In other words, the tip of the lead portion 41 is arranged so as to protrude upward from the first surface 51 on the upper side of the bus bar 50. Therefore, a sufficient contact area can be ensured between the lead portion 41 and the bus bar 50.

[0114] By connecting the protrusion 50 b and the front end of the lead portion 41 by welding or the like, the connection operation between the lead portion 41 and the bus bar 50 can be simplified.

[0115] As described above, in the motor of this modified example, the bus bar 50 has a protrusion 50 b extending from the first surface 51 at its end. The lead 41 and the bus bar 50 are electrically connected while the tip of the lead 41 is supported by the protrusion 50 b.

[0116] <Variation 2>

[0117] Figure 9 FIG is a top view of the bus bar of Modification 2. Figure 9 In the embodiment, the same parts are marked with the same reference numerals and detailed descriptions are omitted.

[0118] Figure 9 The bus bar 50 shown is connected to Figure 1 as well as Figure 5AThe bus bar 50 shown is different in that one end portion 50 a and the other end portion 50 a are folded back in opposite directions with respect to the circumferential direction. Figure 1 as well as Figure 5A Both end portions 50 a of the illustrated bus bar 50 are folded back in the same direction with their respective tips positioned radially inward with respect to the circumferential direction.

[0119] According to this modification, when an excessive mechanical impact is applied to the bus bar 50, deformation of the bus bar 50 can be suppressed. Figure 1 In the bus bar assembly 300 shown in FIG. 1 , when an impact is applied in the radial direction, the central portion of each bus bar 50 is largely displaced because both end portions 50a of each bus bar 50 are fixed. Figure 5A As shown, when both end portions 50a of the bus bar 50 are folded back in the same direction relative to the circumferential direction, the center portion of the bus bar 50 may be significantly displaced and eventually deformed depending on the magnitude and direction of the force applied to the bus bar 50.

[0120] On the other hand, according to this modified example, the two end portions 50a of the bus bar 50 are folded back toward opposite sides relative to the circumferential direction. Therefore, radial forces acting on the bus bar 50 can be offset at the two end portions 50a, thereby suppressing displacement of the central portion of the bus bar 50. Consequently, deformation of the bus bar 50 can be suppressed.

[0121] As described above, in the electric motor of this modified example, one end and the other end of the bus bar 50 are folded back in opposite directions with respect to the outer circumferential direction of the bus bar guide.

[0122] Thus, when an excessive mechanical impact is applied to the bus bar 50 , deformation of the bus bar 50 can be suppressed.

[0123] (Other embodiments)

[0124] A new embodiment can be formed by appropriately combining the components shown in the embodiment and in Modifications 1 and 2. For example, the convex portion 50b shown in Modification 1 can be provided on the bus bar 50 shown in Modification 2.

[0125] The coil 40 may be a general flat ribbon coil or a formed coil. The term "formed coil" herein does not include a coil obtained by simply winding a conductive wire of a certain width and thickness in a spiral shape.

[0126] The formed coil is formed, for example, by preparing a plurality of rectangular plates of different lengths, widths, or thicknesses and joining them together by cold welding, soldering, or other methods. The plates are made of a low-resistance material such as copper or aluminum.

[0127] Alternatively, a shaped coil can be formed by so-called casting, where copper or the like is melted and poured into a mold. Furthermore, a shaped coil can be formed by bending a plate-shaped conductive wire, whose width or thickness has been previously varied midway, at a predetermined location. Alternatively, a shaped coil can be formed by rolling a plate-shaped conductive wire of a constant width and thickness at a predetermined location, changing the width or thickness midway, and then spirally winding it. In short, a shaped coil can be formed by applying other processing in addition to winding the conductive wire, or by a method different from simply winding the conductive wire.

[0128] A sensor other than the temperature detection sensor 70 may be mounted on the stator 100 . For example, a magnetic detection sensor may be arranged inside at least one of the gaps 63 a to 63 d provided in the bus bar guide 60 .

[0129] Industrial applicability

[0130] The bus bar guide of the present invention can accommodate shape variations between the bus bar and the coil and arrange the bus bar at a predetermined position, and is therefore useful in applications to electric motors.

[0131] Description of Reference Numerals

[0132] 10. Tooth; 20. Yoke; 30. Slot; 40. Coil; 41. Lead portion; 50. Busbar; 50a. End portion; 50b. Protrusion; 51. First surface; 52. Second surface; 60. Busbar guide; 60a to 60k. Busbar guide piece; 61. Groove portion; 62. Through hole; 63a to 63d. Gap; 64a to 64d. Fitting portion; 65. Step; 70. Temperature detection sensor; 71. Wiring; 100. Stator; 200. Rotor; 210. Output shaft; 220. Rotor core; 230. Magnet; 300. Busbar assembly; 400. Motor housing; 1000. Motor.

Claims

1. A bus bar guide for fixing a bus bar connected between a plurality of coils of an electric motor, wherein: The bus bar includes a plate-shaped conductor having a pair of first surfaces extending in a radial direction and facing each other, and a pair of second surfaces continuing from the first surfaces and extending in an axial direction and facing each other. The bus bar guide is formed by arranging a plurality of bus bar guide pieces each made of an insulator in a ring shape, and has an inner side surface facing the inside of the ring and an outer side surface facing the outside of the ring. Each of the plurality of bus bar guide pieces is provided with a groove portion for holding the first surface of the bus bar and positioning the bus bar, and the groove portion is formed from near the outer surface toward near the inner surface of the bus bar guide across adjacent bus bar guide pieces.

2. The bus bar guide according to claim 1, wherein The bus bar guide includes at least one set of two bus bar guide pieces that are adjacent to each other and are arranged at a distance from each other along an outer circumferential direction of the bus bar guide.

3. The bus bar guide according to claim 2, wherein: The bus bar guide includes a plurality of sets of two bus bar guide pieces adjacent to each other, and fitting portions for fitting and connecting the bus bar guide pieces to each other are formed in each of at least one set of bus bar guide pieces.

4. The bus bar guide according to claim 3, wherein: The shape of the fitting portion formed on each bus bar guide piece of one set of bus bar guide pieces is the same as the shape of the fitting portion formed on each bus bar guide piece of the other set of bus bar guide pieces.

5. The bus bar guide according to claim 3, wherein The shape of the fitting portion formed on each bus bar guide piece of one set of bus bar guide pieces is different from the shape of the fitting portion formed on each bus bar guide piece of the other set of bus bar guide pieces. The bus bar guide according to claim 2 , wherein: A sensor is arranged between two bus bar guide pieces that are arranged at a distance from each other along an outer circumferential direction of the bus bar guide.

7. The bus bar guide according to claim 6, wherein: At least one bus bar guide piece has a step or a recessed portion on a surface opposite to a surface where the groove is formed, and at least a portion of a wiring connected to the sensor is covered by the step or the recessed portion.

8. The bus bar guide according to claim 1, wherein The depth of the groove is equal to or less than half the width of the second surface of the bus bar.

9. The bus bar guide according to claim 1, wherein Each of the plurality of bus bar guide pieces is provided with a through hole for passing a lead wire portion provided in the coil.

10. The bus bar guide according to any one of claims 1 to 9, wherein The width of the first surface is narrower than the width of the second surface.

11. A busbar assembly, wherein: The bus bar assembly includes at least: the bus bar guide according to any one of claims 1 to 9; and a plurality of bus bars respectively arranged in the plurality of grooves provided on the upper surface of the bus bar guide.

12. An electric motor, wherein: The electric motor at least comprises: a rotor having an output shaft at its axis; a stator provided at a predetermined interval from the rotor; and The busbar assembly according to claim 11 is mounted on the upper portion of the stator. The stator has at least: annular yoke; a plurality of teeth connected to the inner periphery of the yoke at predetermined intervals; as well as a plurality of coils mounted on respective teeth of the plurality of teeth; Two coils among the plurality of coils are electrically connected via one bus bar among the plurality of bus bars.

13. The electric motor according to claim 12, wherein The plurality of bus bars are respectively arranged in a plurality of grooves provided on the upper surface of the bus bar guide. The coil has a lead portion for connecting to the bus bar. The lead portion passes through a through hole provided in the bus bar guide and is led out above the bus bar guide to be electrically connected to the bus bar.

14. The electric motor according to claim 13, wherein Both ends of the bus bar are folded back, and the lead portion and the bus bar are electrically connected in a state in which the lead portion is clamped by the end portions of the bus bar.

15. The electric motor according to claim 14, wherein A protrusion extending from the first surface is provided at an end portion of the bus bar, and the lead portion and the bus bar are electrically connected in a state where the distal end of the lead portion is supported by the protrusion.

16. The electric motor according to claim 14 or 15, wherein: One end and the other end of the bus bar are folded back in opposite directions with respect to the outer circumferential direction of the bus bar guide.

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