Stator and motor

Abstract

The present invention provides a stator having: a stator core having an axially extending cylindrical core back and a plurality of teeth extending radially from the core back and arranged circumferentially; and a plurality of coils respectively wound around the plurality of teeth, wherein the stator has a molded portion covering the plurality of coils, the molded portion having a recess located between circumferentially adjacent coils at an axially side end located on one side of the plurality of coils.

Description

Technical Field

[0001] This invention relates to stators and motors. Background Technology

[0002] A motor having a temperature sensing element for detecting the temperature of a coil is known. For example, Patent Document 1 discloses a configuration in which the coil winding, a thermistor, and a portion of the signal line are sealed with resin in a motor having a stator formed by a coil wound around a stator core.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-045177 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] To accurately detect the temperature of the coil, it is preferable to position the temperature sensing element as close to the coil as possible. In the stator core described in Patent Document 1, the thermistor, which serves as the temperature sensing element and is positioned adjacent to the coil, is sealed with resin.

[0008] However, in the stator core described in Patent Document 1, the temperature sensing element is sealed with resin, making it difficult to easily replace the temperature sensing element.

[0009] Therefore, it is required that the temperature sensing element be easily replaceable and the temperature of the coil be detected with high accuracy in a stator in which the coil is molded from resin.

[0010] The object of the present invention is to provide a configuration in which the temperature sensing element can be easily replaced in a stator in which the coil is molded from resin, and the temperature of the coil can be detected with high accuracy.

[0011] Solution for solving the problem

[0012] An exemplary embodiment of the present invention provides a stator comprising: a stator core having an axially extending cylindrical core back and a plurality of teeth extending radially from the core back and arranged circumferentially; and a plurality of coils, each wound around the plurality of teeth. The stator has a molded portion covering the plurality of coils. The molded portion has a recess located between circumferentially adjacent coils at an axially oriented end located on one side of the plurality of coils.

[0013] Invention Effects

[0014] According to the present invention, a configuration is provided in which the temperature sensing element can be easily replaced in a stator in which the coil is molded from resin, and the temperature of the coil can be detected with high accuracy. Attached Figure Description

[0015] Figure 1 This is a cross-sectional view showing an example of the general structure of a motor.

[0016] Figure 2 This is a three-dimensional diagram showing an example of the general structure of the stator.

[0017] Figure 3 This is a magnified view showing details of the molded part as viewed from the other side of the axial direction.

[0018] Figure 4 yes Figure 3 Sectional view along line IV-IV.

[0019] Figure 5 This is a magnified view showing details of the molded part as seen from one axial side. Detailed Implementation

[0020] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same or corresponding reference numerals are used to denote the same parts in the drawings and will not be described repeatedly. Furthermore, the dimensions of the constituent members in the drawings do not faithfully represent the actual dimensions of the constituent members or the actual size ratios of each constituent member.

[0021] In the following description, the direction in which the axis P of the motor 100 extends is referred to as "axial direction A". The circumferential direction centered on the axis P is referred to as "circumferential direction C", and the radial direction centered on the axis P is referred to as "radial direction R". It should be noted that in this specification, the direction that extends in a straight line between two points equidistant from the center when the component is viewed along the axial direction is also referred to as the circumferential direction.

[0022] Furthermore, the direction described in the specification as "one side of the axial direction" is shown as "A1" in the figure, and the direction described in the specification as "the other side of the axial direction" is shown as "A2" in the figure. It should be noted that the directions shown in the figure are defined only for ease of explanation and do not limit the orientation of the motor of the present invention during use and assembly.

[0023] Furthermore, in the following explanation, the terms "fixed," "connected," and "assembled" (hereinafter, "fixed, etc.") include not only cases where components are directly fixed to each other, but also cases where components are fixed to each other via other components. That is, in the following explanation, the terms "fixed, etc." include the meanings of both direct and indirect fixing of components to each other.

[0024] (motor)

[0025] Figure 1 This is a cross-sectional view showing an example of the schematic configuration of motor 100. (See reference...) Figure 1 The motor 100 has a stator 1, a rotor 2, a housing 5, a temperature sensing element 82, and a circuit board 83. The motor 100 is, for example, a so-called internal rotor type motor in which the rotor 2 is located radially inside the stator 1 on the inner side R2.

[0026] (stator)

[0027] Figure 2 This is a perspective view showing an example of the general structure of stator 1. It should be noted that... Figure 2 In the image, a portion of the molded part 14 is shown in perspective, with some of its teeth 112 illustrated in a state where the coil 12 and insulating member 13 have been removed. (See reference...) Figure 1 and Figure 2 The stator 1 has a stator core 11, multiple coils 12, insulating components 13, and a molding part 14.

[0028] The stator core 11 is, for example, a magnetic body formed by stacking electromagnet steel plates along the axial direction A. The stator core 11 has a core back 111 and a plurality of teeth 112.

[0029] The back of the iron core 111 is cylindrical with the axis P as its center. Multiple teeth 112 extend from the inner circumference of the back of the iron core 111 toward the radially inward side R2 and are located in a position arranged along the circumferential direction C.

[0030] Each of the multiple teeth 112 is fitted with an insulating member 13, which has electrical insulation properties and will be described later.

[0031] A slit SL1 is formed between adjacent teeth 112 in the circumferential direction C. Therefore, the stator core 11 has a plurality of slits SL1 arranged in the circumferential direction.

[0032] In this embodiment, the stator core 11 has a plurality of segmented core portions 11_1 to 11_12 arranged circumferentially C. That is, the stator core 11 is composed of a plurality of segmented core portions 11_1 to 11_12 arranged circumferentially C. Each of the plurality of segmented core portions 11_1 to 11_12 includes a portion of the back side 111 of the core and a tooth portion 112.

[0033] The coil 12 is wound around the teeth 112 on which the insulating member 13 is mounted. Therefore, the coil 12 is located within the slit SL1 between adjacent teeth 112 in the circumferential direction C. The coil 12 is connected to the toothed portion 112 via a lead portion extending axially to one side A1. Figure 1 The circuit board 83 shown is electrically connected.

[0034] An insulating member 13 covers a portion of the outer surface of the tooth 112. The insulating member 13 is located between the tooth 112 and the coil 12. The insulating member 13 electrically insulates the coil 12 from the stator core 11.

[0035] The molding portion 14 covers a portion of the stator core 11 and a plurality of coils 12. The molding portion 14 is, for example, made of a synthetic resin having thermal conductivity and electrical insulation properties. The molding portion 14 has an axial end 141 located on one axial side A1 of the coil 12 and a recessed hole 145. The hole 145 is located between adjacent coils 12 in the circumferential direction C. It should be noted that details regarding the molding portion 14 will be described later.

[0036] (Rotor)

[0037] Re-reference Figure 1 As described above, rotor 2 is located radially inside stator 1, R2. Rotor 2 has rotor core 21 and magnet 22. Rotor 2 rotates relative to stator 1 about axis P.

[0038] (shell)

[0039] The housing 5 houses the stator 1 and the rotor 2. The housing 5 has a shell 51 and a cover 52. The shell 51 has an opening on the opposite axial side A2 and a bottom 517 on the axial side A1. The shell 51 houses the stator 1 and the rotor 2. The cover 52 closes the opening of the shell 51.

[0040] (Temperature sensing element and circuit board)

[0041] The temperature sensing element 82 is, for example, a thermistor that detects the temperature of the coil 12. The temperature sensing element 82 is connected to the circuit board 83 via signal line 822 to output a signal. The temperature sensing element 82 and signal line 822 constitute a temperature sensor. The temperature sensing element 82 generates a temperature signal based on the detected temperature of the coil 12 and outputs it to the circuit board 83 via signal line 822.

[0042] The circuit board 83 is, for example, a control board for controlling the drive of the motor 100. The circuit board 83 controls, for example, the supply of drive current to the stator 1. The circuit board 83 is located on one axial side A1 of the stator 1 and the rotor 2.

[0043] As described above, the stator 1 of the motor 100 includes: a stator core 11 having a cylindrical core back 111 extending along the axial direction A and a plurality of teeth 112 extending radially inward from the core back 111 to the radial direction R2 and arranged circumferentially C; and a plurality of coils 12, each wound around the plurality of teeth 112. The stator 1 has a molded portion 14 covering the plurality of coils 12. The molded portion 14 has a hole 145 as a recess at an axial side end 141 located on one axial side A1 of the plurality of coils 12, the hole 145 being located between adjacent coils 12 in the circumferential direction C.

[0044] Furthermore, the motor 100 includes the stator 1, rotor 2, housing 5, circuit board 83, and temperature sensing element 82 described above. The rotor 2 rotates relative to the stator 1 about an axis P extending along axial direction A. The housing 5 houses the stator 1 and rotor 2. The circuit board 83 is located on one axial side A1 of the stator 1 and rotor 2. The temperature sensing element 82 detects the temperature of the coil 12 and outputs a signal to the circuit board 83.

[0045] Based on the above configuration, the temperature sensing element 82, which serves as a temperature sensing sensor, can be positioned closer to the coil 12 than the surface of the axial end 141 of the molding portion 14, without needing to embed it inside the molding portion 14. Furthermore, since the temperature sensing element 82 is not embedded inside the molding portion 14, the configuration and replacement of the temperature sensing sensor, including the temperature sensing element 82 and the signal line 822, can be easily performed.

[0046] Furthermore, according to the above configuration, by placing the temperature sensing element 82 in the hole portion 145 of the molding portion 14, the temperature of the coil 12 can be detected with higher accuracy compared to the case where the temperature sensing element 82 is placed on the surface of the axial side end portion 141 of the molding portion 14.

[0047] Therefore, a configuration can be provided in which a temperature sensing sensor can be easily configured and replaced in the stator 1 where the coil 12 is molded, and the temperature of the coil 12 can be detected with high accuracy. Furthermore, based on the above configuration, a motor 100 having such a stator 1 can be easily implemented.

[0048] (Details of the molding department)

[0049] Figure 3 This is a partial enlarged view showing details of the molded portion 14 as viewed from the other side of the axial direction. Figure 4 yes Figure 3 Sectional view along line IV-IV. Figure 5 This is a partially enlarged view showing details of the molded portion 14 as viewed from one axial side. It should be noted that... Figure 4 In the diagram, the temperature sensing element 82 and the signal line 822 are represented by dashed lines.

[0050] Reference Figure 1 , Figure 2 as well as Figures 3 to 5 The molding section 14 has a plurality of molding blocks 14_1 to 14_12, which respectively cover the coil 12 wound on the toothed section 112. The plurality of molding blocks 14_1 to 14_12 respectively cover the coil 12 and a portion of the toothed section 112 in the plurality of segmented iron core sections 11_1 to 11_12.

[0051] Multiple molding blocks 14_1 to 14_12 are formed with the same shape. For example, the multiple molding blocks 14_1 to 14_12 are formed as columnar shapes extending along the axial direction A. Because the multiple molding blocks 14_1 to 14_12 are formed with the same shape, the same mold can be used for molding each molding block. The multiple molding blocks 14_1 to 14_12 are arranged circumferentially C, thereby constituting the molding section 14.

[0052] The hole 145 can also be located, for example, between two molding blocks 14_1 and 14_2 covering two adjacent coils 12 in the circumferential direction C. Molding blocks 14_1 and 14_2 are located adjacent to each other in the circumferential direction C. Figure 3 and Figure 4 As shown, the hole 145 is formed by the first groove 1451 of the molding block 14_1 and the second groove 1452 of the molding block 14_2 arranged circumferentially.

[0053] Especially as Figure 2 , Figure 3 as well as Figure 4 As shown, the molding block 14_1 has, for example, a first groove 1451 located on one circumferential side of the molding block 14_1 and a second groove 1452 located on the other circumferential side of the molding block 14_1. The first groove 1451 opens at C1 on one circumferential side and extends to the center of the molding portion 14 in the axial direction A. The second groove 1452 opens at C2 on the other circumferential side and extends to the center of the molding portion 14 in the axial direction A.

[0054] When viewed along the circumferential direction C, the hole 145 extends axially from the end 141 on one side of the molded portion 14 in the axial direction A to a position overlapping with the coil 12 adjacent in the circumferential direction C. For example... Figure 4 As shown, the hole portion 145 has a bottom portion 1455. Therefore, when the temperature sensing element 82 is disposed in the hole portion 145, the temperature sensing element 82 can be positioned in the axial direction A by means of the bottom portion 1455.

[0055] Furthermore, in the above configuration, multiple molded blocks 14_1 to 14_12 of the same shape are arranged along the circumferential direction C. Therefore, the hole 145 is located between the multiple molded blocks 14_1 to 14_12 that are adjacent in the circumferential direction C. That is, when viewed along the axial direction A, the hole 145 is, for example, located at a position that overlaps with the joints of the segmented core portions 11_1 and 11_2 that are adjacent in the circumferential direction C.

[0056] The aperture 145 is located, for example, between two coils 12 that are adjacent in the circumferential direction C and carry currents of different phases.

[0057] A temperature sensing element 82 is disposed within a hole 145 located between two coils 12 through which currents flow in different phases. The temperature sensing element 82 then performs temperature detection based on the heat generated by the two coils 12 in different phases. Thus, the temperature between the two coils 12 in different phases can be detected.

[0058] It should be noted that the temperature sensing element 82 may be disposed in the hole 145 located between the adjacent molding blocks 14_2 and 14_3 in the circumferential direction C, or it may not be disposed in the hole 145.

[0059] The hole 145 is located radially outward from the line CL1, which is radially outward from the center of the coil 12 wound around the tooth 112.

[0060] like Figure 3 As shown, the distance between the circumferential center positions CL21 and CL22 of adjacent coils 12 in the circumferential direction C is greater on the radially outer side of the coil 12 than on the radially inner side. Therefore, the distance between adjacent coils 12 in the circumferential direction C is greater on the radially outer side of the line CL1 (which is closer to the radial center of the coil 12) than on the radially inner side of the line CL1 (which is closer to the radial center of the coil 12). Based on this configuration, the hole 145 can be easily positioned on the radially outer side of the line CL1 (which is closer to the radial center of the coil 12).

[0061] Especially as Figure 3 and Figure 5 As shown, among the plurality of molding blocks 14_1 to 14_12, molding blocks 14_1 and 14_2 that are adjacent in the circumferential direction C are located at a position separated by a gap GP1 in the circumferential direction C. That is, the circumferential end 1401 of molding block 14_1 and the circumferential end 1402 of molding block 14_2 are separated by a width L1 in the circumferential direction C.

[0062] Hole 145 is located at one circumferential end 1401 of molded block 14_1 and the other circumferential end 1402 of molded block 14_2. Thus, hole 145 is connected to gap GP1.

[0063] In the stator core 11 with a split core, it is easy to wind more coils 12 onto the teeth 112.

[0064] Furthermore, for example, when the stator core 11 for the segmented core is metal and the molding part 14 is resin, the dimensional accuracy of the resin molding part 14 is lower than that of the metal segmented core.

[0065] In the above configuration, the two molded blocks 14_1 and 14_2 covering the adjacent coils 12 in the circumferential direction C are located at a position separated by a gap GP1 in the circumferential direction C. This allows for a clearance that takes into account dimensional tolerances between the adjacent molded blocks 14_1 and 14_2 in the circumferential direction C. Therefore, for example, it is possible to prevent gaps from forming between the adjacent segmented core portions 11_1 and 11_2 in the circumferential direction C.

[0066] Furthermore, the hole 145 is connected to the gap GP1 between the adjacent molding blocks 14_1 and 14_2 in the circumferential direction C. Therefore, by arranging the temperature sensing element 82 in the hole 145, the temperature of the coil 12 can be detected with higher accuracy.

[0067] In addition, especially referring to Figure 1 and Figure 5 The molding part 14 has a contact part 146 at its end 142 on the other side of the axial direction of the coil 12, which contacts the inner surface of the cover 52 of the housing 5. The contact part 146 can directly contact the inner surface of the cover 52, or it can indirectly contact the inner surface of the cover 52 via a heat-conducting member located between the contact part 146 and the cover 52.

[0068] As described above, the hole 145 is located at the axial side end 141 of the molding portion 14, which is on the opposite side of the contact portion 146 in the axial direction A.

[0069] The molding portion 14 has a contact portion 146 that contacts the outer casing 5, thus enabling efficient and direct heat transfer from the coil 12 to the outer casing 5 without an air gap between the contact portion 146 and the casing 52. Furthermore, the hole 145 is located at one axial end 141, which is positioned opposite the other axial end 142 along the axial direction A. Therefore, compared to the case where the hole 145 is located at the other axial end 142, the contact area between the contact portion 146 and the outer casing 5 can be increased. This improves heat dissipation.

[0070] (Other implementation methods)

[0071] The embodiments of the present invention have been described above, but these embodiments are merely examples for implementing the present invention. Therefore, the present invention is not limited to the above embodiments, and can be implemented by appropriate modifications without departing from its spirit.

[0072] In the described embodiment, the motor 100 is a so-called inner rotor type motor in which the rotor 2 is located radially inside the stator 1, R2. However, the motor can also be an outer rotor type motor. That is, the rotor 2 can also be located radially outside the stator.

[0073] In the described embodiment, the hole 145 is located radially outward of the line CL1, which is the radial center of the coil 12 wound around the tooth 112. However, the recess may also be located radially inward of the line CL1, which is the radial center of the coil wound around the tooth.

[0074] In the described embodiment, the hole 145 is located between two coils 12 that are adjacent in the circumferential direction C and carry currents of different phases. However, the recess may also be located between two coils that are adjacent in the circumferential direction and carry currents of the same phase.

[0075] In the embodiment described, the stator core 11 has a plurality of segmented core portions 11_1 to 11_12 arranged circumferentially C. However, the stator core may not be segmented circumferentially.

[0076] In the described embodiment, each of the plurality of segmented core portions 11_1 to 11_12 includes a tooth 112. However, some of the plurality of segmented core portions may not have teeth.

[0077] In the described embodiment, the molding section 14 has a plurality of molding blocks 14_1 to 14_12 that respectively cover the coil 12 wound on the tooth section 112. That is, in the above configuration, one molding block is formed for each coil. However, the molding section may also be configured to form one molding block for multiple coils. In addition, a single molding block may be formed for all the coils of the stator.

[0078] In the described embodiment, the hole 145 is located, for example, at the circumferential ends of the molding blocks 14_1 and 14_2 that are adjacent in the circumferential direction C. However, the recess may also be located, for example, at only one of the circumferential ends of the molding blocks that are adjacent in the circumferential direction.

[0079] In the described embodiment, the plurality of molded blocks 14_1 to 14_12 are formed to have the same shape. However, at least a portion of the plurality of molded blocks may also have different shapes.

[0080] In the embodiment described, the circuit board 83 is located on one axial side A1 of the stator 1 and the rotor 2. However, the circuit board may also be located on the other axial side of the stator and rotor.

[0081] In the described embodiment, the hole 145 is located at the axial side end 141 of the molding portion 14, which is on the opposite side of the contact portion 146 in the axial direction A. However, the recess may also be located at the other axial side end, which is on the same side as the contact portion in the axial direction. The recess may also be located at both the axial side end and the other axial side end of the molding portion.

[0082] In the described embodiment, the axial end portion 141 of the molding portion 14 is planar. However, the axial end portion of the molding portion may also include a step. For example, the radially inner portion of the molding portion may be axially recessed compared to the radially outer portion at the axial end portion.

[0083] (Example of composition)

[0084] It should be noted that this technology can also be configured as follows.

[0085] (1) A stator having: a stator core having an axially extending cylindrical core back and a plurality of teeth extending radially from the core back and arranged circumferentially; and a plurality of coils wound around the plurality of teeth, wherein the stator has a molded portion covering the plurality of coils, the molded portion having a recess located between circumferentially adjacent coils at an axially side end located on one side of the plurality of coils.

[0086] (2) In the stator described in (1), the recess is located radially outward from the radial center of the coil wound around the teeth.

[0087] (3) In the stator described in (1) or (2), the recess is located between two coils in two adjacent coils in the circumferential direction through which currents of different phases flow.

[0088] (4) In any one of (1) to (3) the stator, the stator core has a plurality of segmented core portions arranged circumferentially to form the back of the core, at least a portion of the plurality of segmented core portions includes the teeth, the molding portion has a plurality of molding blocks, the plurality of molding blocks respectively covering the coil wound on the teeth included in the at least a portion of the segmented core portions, the circumferentially adjacent molding blocks of the plurality of molding blocks are located at a position circumferentially spaced apart, and the recess is located at the circumferential end of each of the circumferentially adjacent molding blocks and connected to the gap.

[0089] (5) In the stator described in (4), the plurality of molded blocks are of the same shape as each other.

[0090] (6) A motor having a stator according to any one of (1) to (5); a rotor that rotates relative to the stator about an axially extending axis; a housing that houses the stator and the rotor; a circuit board located on one axial side of the stator and the rotor; and a temperature sensing element that detects the temperature of the coil and outputs a signal to the circuit board, wherein at least a portion of the temperature sensing element is located within the recess in the motor.

[0091] (7) In the motor described in (6), the molding portion has a contact portion that contacts the housing at an axially opposite end located on the other side of the coil, and the recess is located at an axially opposite end of the molding portion on the side opposite to the contact portion in the axial direction.

[0092] Industrial availability

[0093] The configuration of this invention can be applied to a stator having a stator core and coils.

[0094] Explanation of reference numerals in the attached figures

[0095] 1—Stator, 2—Rotor, 11—Stator core, 11_1~11_12—Divided core section, 111—Back of core, 112—Tooth, 12—Coil, 13—Insulating component, 14—Molded section, 14_1~14_12—Molded block, 1401—One end in the circumferential direction, 1402—The other end in the circumferential direction, 141—One end in the axial direction, 142—The other end in the axial direction, 145—Hole, 1451—First slot, 1452—The... Two slots, 1455—bottom, 146—contact, 2—rotor, 21—rotor core, 22—magnet, 5—outer shell, 51—housing, 517—bottom, 52—cover, 82—temperature sensing element, 822—signal line, 83—circumferential board, 100—motor, A—axial, C—circumferential, CL1—line, CL21—circumferential center position, CL22—circumferential center position, GP1—gap, P—axis, R—radial, SL1—slit.

Claims

1. A stator, said stator having: A stator core having an axially extending cylindrical core back and a plurality of teeth extending radially from the core back and arranged circumferentially; and Multiple coils are wound around the multiple teeth, respectively. The stator has a molded portion covering the plurality of coils. The molding portion has a recess located between adjacent coils in the circumferential direction at one end of the axial side of the plurality of coils.

2. The stator according to claim 1, wherein, The recess is located radially outward from the radial center of the coil wound around the teeth.

3. The stator according to claim 1, wherein, The recess is located between two coils that are adjacent in the circumferential direction and carry currents of different phases.

4. The stator according to claim 1, wherein, The stator core has multiple segmented core portions arranged circumferentially to form the back of the core, and at least a portion of the segmented core portions includes the teeth. The molding section has a plurality of molding blocks, each of which covers the coil wound around the teeth included in the at least a portion of the segmented iron core section. Among the plurality of molded blocks, adjacent molded blocks in the circumferential direction are located at positions separated by gaps in the circumferential direction. The recess is located at the circumferential ends of adjacent molded blocks in the circumferential direction and is connected to the gap.

5. The stator according to claim 4, wherein, The multiple molded blocks are all the same shape.

6. A motor, said motor having: Stator according to any one of claims 1 to 5; The rotor rotates relative to the stator about an axis extending along the axial direction. A housing that accommodates the stator and the rotor; The circuit board is located on one axial side of the stator and the rotor; and A temperature sensing element detects the temperature of the coil and outputs a signal to the circuit board. In the motor, at least a portion of the temperature sensing element is located within the recess.

7. The motor according to claim 6, wherein, The molding portion has a contact portion that contacts the housing at its end located on the other side of the axial direction of the coil. The recess is located at the axial end of the molded portion, on the side opposite to the contact portion in the axial direction.

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