Motor, and pump device

Abstract

To provide a motor capable of improving a cooling performance of a heat dissipation member by enlarging a heat capacity of the heat dissipation member even without increasing a plate thickness of the heat dissipation member, and a pump device.SOLUTION: A motor 3 comprises: a rotor 5 which is rotated around a rotation axial line L; a stator 6 which is disposed in a periphery of the rotor 5; a resin seal member 70 covering the stator 6 and including a cylinder part 74 which is opened at one side L1 in an axial line direction along the rotation axial line L; a circuit board 8 which is stored in the cylinder part 74; a cover member 9 covering the cylinder part 74 from the one side L1 and including a heat dissipation member 92 consisting of a metallic tabular member; and a potting member 18 which is provided at the one side L1 of the heat dissipation member 92. The heat dissipation member 92 includes: a recess 924, which is recessed at another side L2, on a first face 921a at the one side; and a contact part 927, which is in contact with the circuit board 8, on a second face 921b at the other side L2. The potting member 18 is provided in the recess 924.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a motor and a pump device equipped with a heat dissipation member for cooling a circuit board. [Background technology]

[0002] A motor equipped with a heat dissipation member for cooling a circuit board is described in Patent Document 1. The motor in this document has a rotor, a stator arranged in the circumferential direction of the rotor, a housing covering the stator, a circuit board provided on one side of the rotation axis of the motor and accommodated in an accommodating recess of the housing, a cover covering the accommodating recess, and a heat dissipating material arranged between the cover and the circuit board. The cover is made of a metal plate-like member and is formed by pressing. The cover has a recess that is recessed toward the circuit board side and sandwiches the heat dissipating material between the cover and the circuit board, and a plurality of ribs. Heat generated in the circuit board is dissipated from the cover via the heat dissipating material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-151925 Summary of the Invention [Problem to be solved by the invention]

[0004] Motors such as those described in Patent Document 1 are required to have high output. However, when the motor has high output, the amount of heat generated by the circuit board increases, so that it is required to cool the circuit board more. In this case, it is possible to increase the thickness of the cover that functions as a heat dissipation member, thereby increasing the heat capacity of the cover and improving the cooling performance of the cover. However, when the cover is made thick, press processing becomes difficult. For this reason, there is a limit to how thick the cover can be made, and there is a problem that the heat capacity of the cover cannot be increased.

[0005] In view of the above problems, an object of the present invention is to provide a motor and a pump device that can increase the thermal capacity of a heat dissipation member and improve the cooling performance of the heat dissipation member without increasing the plate thickness of the heat dissipation member. [Means for solving the problem]

[0006] In order to solve the above problems, the motor of the present invention comprises a rotor that rotates around a rotation axis, a stator arranged around the rotor, a resin sealing member that covers the stator and has a cylindrical portion that opens on one side in the axial direction along the rotation axis, a circuit board housed in the cylindrical portion, a cover member that covers the cylindrical portion from the one side and has a heat dissipation member made of a metal plate-shaped member, and a potting member provided on the one side of the heat dissipation member, wherein the heat dissipation member has a recess on a first surface on the one side that is recessed toward the other side in the axial direction, and a contact portion on a second surface on the other side in the axial direction that contacts the circuit board, and the potting member is provided in the recess.

[0007] According to the present invention, a potting material is provided in the recess of the metal heat dissipation member. Therefore, even if the plate thickness of the heat dissipation member is not increased, the heat capacity of the heat dissipation member is increased by providing the potting material, and the cooling performance of the heat dissipation member is improved. In addition, since the potting material is provided in the recess, it is easy to arrange the potting material on the heat dissipation member.

[0008] In the present invention, a heat transfer member is disposed between the contact portion and the circuit board. This can be done.

[0009] In the present invention, it is preferable that the heat transfer member is elastically deformed between the contact portion and the circuit board, whereby the heat dissipation member and the circuit board can be reliably brought into contact with each other via the heat transfer member.

[0010] In the present invention, it is preferable that the circuit board includes an electronic element on the one surface, and the heat transfer member is in contact with the electronic element. Here, when the circuit board operates, the electronic element becomes a heat source that generates heat. Therefore, since the heat transfer member is in contact with the electronic element, the heat dissipation member can efficiently cool the circuit board through the heat transfer member.

[0011] In the present invention, the electronic element is preferably a field effect transistor. Here, when the circuit board is in operation, the field effect transistor is most likely to generate heat. Therefore, since the heat transfer member is in contact with the field effect transistor, the heat dissipation member can cool the circuit board more efficiently through the heat transfer member.

[0012] In the present invention, it is preferable that the heat dissipation member has a protrusion protruding to the other side at a position on the second surface that overlaps with the recess in the axial direction, and the protrusion is the contact portion. In this way, the contact portion overlaps with the potting member, which is a portion having a large heat capacity, in the axial direction, so that the heat dissipation member can efficiently cool the circuit board.

[0013] The pump device of the present invention includes the motor described above and an impeller that is rotationally driven by the motor. Effect of the Invention

[0014] According to the present invention, by providing the potting member on the heat dissipation member, the heat capacity of the heat dissipation member is increased without increasing the plate thickness of the heat dissipation member, thereby improving the cooling performance of the heat dissipation member. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a perspective view of the pump device according to the embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the pump device shown in FIG. [Diagram 3] 2 is an enlarged cross-sectional perspective view of one end of the pump device shown in FIG. 1. [Figure 4] 2 is an exploded perspective view showing a state in which a cover is removed from the motor shown in FIG. 1. [Diagram 5] FIG. [Figure 6] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] A pump device including a motor according to the present invention will be described below with reference to the drawings. In the following description, the direction along the rotation axis L will be described as the axial direction. In the axial direction, one side will be labeled L1 and the other side will be labeled L2. In the following description, the radial direction and circumferential direction about the rotation axis will be simply referred to as the "radial direction" and the "circumferential direction", respectively.

[0017] (Overall composition) Fig. 1 is a perspective view of a pump device 1 of this embodiment. Fig. 2 is a cross-sectional view of the pump device 1 shown in Fig. 1. Fig. 3 is an exploded perspective view showing a state in which a cover is removed from the motor shown in Fig. 1. Fig. 4 is an enlarged cross-sectional perspective view of an end portion on one side L1 of the pump device 1 shown in Fig. 1. Fig. 5 is a perspective view of a cover member. Fig. 6 is an exploded perspective view of the cover member.

[0018] As shown in FIG. 1 and FIG. 2, the pump device 1 includes a case 2, a motor 3 including a rotor 5 and a stator 6, and a resin impeller 4 arranged on the other axial side L2 of the rotor 5. The case 2 accommodates the impeller 4 and defines a pump chamber 20. The motor 3 includes a resin housing 7 that covers the stator 6, a circuit board 8 connected to the coil 63 of the stator 6, a cover member 9 that covers the circuit board 8 from the one side L1 and includes a heat dissipation member 92 made of a metal plate-like member, a potting member 18 provided on the one side L1 of the heat dissipation member 92, and a heat transfer member 15 arranged between the heat dissipation member 92 and the circuit board 8. The pump device 1 moves a fluid in the pump chamber 20 by rotating the impeller 4 together with the rotor 5 about the rotation axis L.

[0019] (case) As shown in FIG. 2, the case 2 defines a pump chamber 20 between the case 2 and the housing 7. The case 2 includes an opposing wall 23 opposing the impeller 4 on the other side L2, and a side wall 24 extending in the circumferential direction on the radially outer side of the impeller 4. As shown in FIGS. 1 and 2, the case 2 includes a suction pipe 21 extending along the axial direction, and a discharge pipe 22 extending in a direction perpendicular to the axial direction. The suction pipe 21 and the discharge pipe 22 include a suction port 21a and a discharge port 22a at their ends, respectively. The suction pipe 21 and the suction port 21a are provided concentrically with respect to the rotation axis L. The discharge pipe 22 is located radially outward of the impeller 4.

[0020] (Impeller) The impeller 4 is made of resin. As shown in Fig. 2, the impeller 4 includes a circular first plate 41, a plurality of blades 42 that protrude from the first plate 41 to the other side L2 and are arranged at regular intervals in the circumferential direction, and a circular second plate 43 that abuts the tips of the blades 42. When the impeller 4 rotates integrally with the rotor 5 about the rotation axis L by driving the motor 3, the blades 42 cause the fluid in the pump chamber 20 to flow in the rotation direction. As a result, centrifugal force is generated in the fluid, which is low-pressure on the radial inside and high-pressure on the radial outside, and is sucked in through the suction port 21a and discharged through the discharge port 22a.

[0021] (Motor) As shown in FIG. 2, the rotor 5 includes a cylindrical holder 51 extending in the axial direction and a cylindrical magnet 10 held on the outer circumferential surface of the holder 51. The holder 51 is made of resin. The holder 51 includes a small diameter portion 52 that holds the magnet 10 on its outer circumferential surface, a circular abutment portion 53 that abuts against an end of the magnet 10 on one side L1, and a large diameter portion 54 that protrudes from the outer circumferential edge of the abutment portion 53 to the other side L2. The outer diameter dimension of the small diameter portion 52 is smaller than the outer diameter dimension of the large diameter portion 54. The small diameter portion 52 and the large diameter portion 54 are provided coaxially. The small diameter portion 52 holds a bearing 56 inside. The first plate 41 is provided integrally with the large diameter portion 54 on the other side L2 of the large diameter portion 54. The rotor 5 is rotatably supported by the support shaft 11 via the bearing 56.

[0022] The outer diameter of magnet 10 is approximately the same as the outer diameter of large diameter portion 54. Magnet 10 and small diameter portion 52 are bonded together by applying an adhesive between magnet 10 and small diameter portion 52. At this time, magnet 10 is positioned in the axial direction by abutting against abutment portion 53.

[0023] The stator 6 includes a stator core 61 arranged in an annular shape centered on the rotation axis L, an insulator 62 held by the stator core 61, and a coil 63 wound around the stator core 61 via the insulator 62. The stator core 61 includes an annular portion surrounding the rotor 5, and a plurality of salient poles protruding radially inward from the annular portion. The coil 63 is wound around the outer periphery of the insulator 62 covering the salient poles. In this embodiment, the motor 3 is a three-phase motor. Thus, the coil 63 includes a U-phase coil, a V-phase coil, and a W-phase coil.

[0024] The housing 7 includes a first partition 71 facing the pump chamber 20, a second partition 72 interposed between the stator 6 and the magnet 10, and a third partition 73 facing an end face of one side L1 of the rotor 5. The first partition 71 defines the pump chamber 20 between the case 2 and the housing 7. The resin sealing member 70 is a resin portion formed when the stator 6 is insert-molded using polyphenylene sulfide (PPS) or the like. The resin sealing member 70 may also be formed by insert-molding the stator 6 using Bulk Molding Compound (BMC) or the like.

[0025] As shown in Fig. 2, the support shaft 11 is a rod-shaped member made of metal. The central axis of the support shaft 11 coincides with the rotation axis L of the rotor 5. An end of one side L1 of the support shaft 11 is press-fitted into a hole 73a formed in the third partition wall 73. An annular plate member 12 is fixed to an end of the other side L2 of the support shaft 11. The plate member 12 abuts against an end of the bearing 56 on one side L1.

[0026] As shown in Figs. 2 and 3, the housing 7 includes a cylindrical portion 74 that opens to one side L1 at an end of the one side L1 of the motor 3, and a flange portion 75 that protrudes radially outward from the end of the one side L1 of the cylindrical portion 74. The cylindrical portion 74 includes a connector housing 76 that covers a connector pin 82 that is electrically connected to the circuit board 8. The circuit board 8 is accommodated inside the cylindrical portion 74. The flange portion 75 is provided around the entire circumference of the cylindrical portion 74. The housing 7 includes a mounting portion 78 for mounting the circuit board 8. The mounting portion 78 is provided inside the end of the one side L1 of the cylindrical portion 74. As shown in Fig. 4, the mounting portion 78 includes fixing portions 79 for fixing the circuit board 8 at three locations.

[0027] The circuit board 8 is provided with a circuit that controls the power supply to the coil 63, and the like. As shown in FIG. 4, the circuit board 8 is provided with a protrusion 83 at a position corresponding to the fixing portion 79. As shown in FIGS. 2 to 4, the circuit board 8 is placed on the mounting portion 78, and the protrusion 83 is fixed to the fixing portion 79. The circuit board 8 is provided with an electronic element 81 on a surface 810 of one side L1 of the circuit board 8. The electronic element 81 is a field effect transistor that controls the power supply. The electronic element 81 serves as a heat source that generates heat when controlling the power supply to the coil 63.

[0028] As shown in Figures 2 to 6, the cover member 9 includes a resin frame member 91 having an opening 91a that opens in the axial direction, a heat dissipation member 92 that covers the opening 91a from the other side L2, and a sealing member 93 arranged between the frame member 91 and the heat dissipation member 92.

[0029] 3 and 6, the frame member 91 includes a plate-shaped annular portion 911 having a circular opening 91a, a tubular portion 912 extending from the radial outside of the annular portion 911 to the other side L2, and a flange portion 913 protruding radially outward from an end of the other side L2 of the tubular portion 912. The outer shape of the flange portion 913 is the same as the outer shape of the flange portion 75 of the tubular portion 74.

[0030] As shown in Figs. 2 to 5, the heat dissipation member 92 is located radially inside the cylindrical portion 912. The heat dissipation member 92 is made of a single metal plate-like member and is formed by pressing. The heat dissipation member 92 is made of metal such as copper, brass, or aluminum. The heat dissipation member 92 is circular when viewed from the axial direction. The heat dissipation member 92 includes a shielding portion 921 that covers the opening 91a from one side L1, a peripheral wall portion 922 that is bent from the outer circumferential edge of the shielding portion 921 to the other side L2 and extends in the axial direction, and a flange portion 923 that protrudes radially outward from the edge of the peripheral wall portion 922.

[0031] 2 to 4, the shielding portion 921 has recesses 924, 925 on a first surface 921a of one side L1 that are recessed toward the other side L2. The recess 924 overlaps, in the axial direction, with a region in which the electronic element 81 is disposed. As shown in FIGS. 2, 3, and 5, the shielding portion 921 has a protrusion 926 on a second surface 921b that protrudes toward the other side L2 at a position that overlaps with the recess 924 in the axial direction. and a contact portion 927 on the second surface 921b that comes into contact with the circuit board 8. In this embodiment, the protrusion 926 is the contact portion 927.

[0032] 3 and 6, the shielding portion 921 has a circular shape when viewed in the axial direction and has an outer diameter larger than that of the opening 91a. The shielding portion 921 contacts the annular portion 911 from the other side L2 in the axial direction. This positions the shielding portion 921 relative to the annular portion 911 in the axial direction.

[0033] 6, the heat dissipation member 92 has cutout portions 928 formed by cutting the outer periphery of the flange portion 923 toward the inner periphery. The cutout portions 928 are provided at nine locations at equal intervals in the circumferential direction. When the heat dissipation member 92 is fixed to the frame member 91, the cutout portions 928 engage with protrusions 917 provided on the inner periphery of the tube portion 912. This positions the heat dissipation member 92 in the circumferential direction.

[0034] 5, when the heat dissipation member 92 is fixed to the frame member 91, the tip of the protrusion 917 is thermally deformed to form a crimped portion 917a. The crimped portion 917a engages the outer circumferential edge of the flange portion 923 from the other side L2. In this way, the heat dissipation member 92 is fixed to the frame member 91.

[0035] 3 and 6, the seal member 93 is disposed between the frame member 91 and the heat dissipation member 92, and is in close contact with the frame member 91 and the heat dissipation member 92. The seal member 93 in this embodiment is an O-ring. The seal member 93 is disposed in a radial gap between the cylindrical portion 912 and the peripheral wall portion 922, and is in close contact with the inner circumferential surface of the cylindrical portion 912 and the outer circumferential surface of the peripheral wall portion 922 in a state in which the seal member 93 is elastically deformed in the radial direction.

[0036] As shown in FIG. 2 and FIG. 3, the cover member 9 is fixed to the flange portion 75 of the housing 7 by welding, and covers the tube portion 74 from one side L1. In this embodiment, a welding portion 94 that joins the frame member 91 and the tube portion 74 is provided between the frame member 91 and the tube portion 74. The welding portion 94 is provided on the flange portion 75 provided at the end of the one side L1 of the tube portion 74 and on the end of the other side L2 of the flange portion 913 of the frame member 91. As shown in FIG. 2 to FIG. 5, the frame member 91 has a welding protrusion 951 that protrudes from the end of the other side L2 of the tube portion 612 to the other side L2. The welding protrusion 951 is annular. The flange portion 75 has an annular welding recess 952 that faces the welding protrusion 951 from the other side L2. Alternatively, a configuration may be adopted in which a recessed welding portion is provided on the one side L1 of the frame member 91, and a protruding welding portion is provided on the flange portion 75, protruding on the one side L1.

[0037] The cover member 9 and the housing 7 are fixed to each other by welding. As a welding method, ultrasonic welding, vibration welding, or the like is used. In this embodiment, with the welding convex portion 951 fitted into the welding concave portion 952, a welding head is pressed against the flange portion 913 to weld the welding convex portion 951 and the welding concave portion 952. During welding, the flange portion 75 is supported from one side L1 by a jig.

[0038] 2 to 4, the potting member 18 is provided in the recess 924. More specifically, the recess 924 is filled with the potting member 18. The potting member 18 is made of a resin material such as epoxy resin, or a metal material such as copper. For example, when the potting member 18 is made of epoxy resin, the potting member 18 may be provided in the recess 924 using an adhesive containing epoxy resin as a main component.

[0039] The heat transfer member 15 is a thin sheet-like heat transfer member made of silicon gel or the like, and has elasticity. As shown in FIGS. 2 to 4, the heat transfer member 15 has a protrusion 927 which is a contact portion 927. 6 and the circuit board 8 while being elastically deformed. The heat transfer member 15 contacts the heat dissipation member 92 and the circuit board 8 to transfer heat from the circuit board 8 to the heat dissipation member 92. At this time, the heat transfer member 15 is in contact with the surface of one side L1 of the circuit board and the electronic element 81. The heat transfer member 15 may be grease or the like.

[0040] (Action and effect) According to this embodiment, the potting member 18 is provided in the recess 924 of the metal heat dissipation member 92. Therefore, even if the plate thickness of the heat dissipation member 92 is not increased, the heat capacity of the heat dissipation member 92 is increased by providing the potting member 18, thereby improving the cooling performance of the heat dissipation member 92. In addition, since the potting member 18 is provided in the recess 924, it is easy to arrange the potting member 18 on the heat dissipation member 92.

[0041] The motor 3 has a heat transfer member 15 disposed between the contact portion 927 and the circuit board 8. The heat transfer member 15 is elastically deformed between the contact portion 927 and the circuit board 8. This allows the heat dissipation member 92 and the circuit board 8 to be reliably in contact with each other via the heat transfer member 15.

[0042] The circuit board 8 has an electronic element 81 on one surface 810. The heat transfer member 15 is in contact with the electronic element 81. The electronic element 81 is a field effect transistor. Here, when the circuit board 8 operates to control the power supply to the coil 63, the field effect transistor is most likely to generate heat. Therefore, since the heat transfer member 15 is in contact with the electronic element 81, which is a field effect transistor, the heat dissipation member 92 can cool the circuit board 8 more efficiently via the heat transfer member 15.

[0043] The heat dissipation member 92 has a protrusion 926 that protrudes toward the other side L2 at a position on the second surface 921b that overlaps with the recess 924 in the axial direction. The protrusion 926 is a contact portion 927. Therefore, the contact portion 927 overlaps with the potting member 18, which is a portion having a large heat capacity, in the axial direction, so that the heat dissipation member 92 can efficiently cool the circuit board 8.

[0044] (Modification) In the above embodiment, the potting member 18 is provided in the recess 924, but this is not limited to the above. The potting member 18 may be provided only in the recess 925. Moreover, the potting member 18 may be provided in both the recess 924 and the recess 925.

[0045] In the above embodiment, the contact portion 927 is provided on the protrusion 926 formed at a position overlapping with the recess 924 in the axial direction, but this is not limited thereto. The contact portion 927 may be provided on a protrusion formed at a position not overlapping with the recess 924 in the axial direction. Furthermore, a plurality of contact portions 927 may be provided.

[0046] In the above embodiment, the electronic element 81 is a field effect transistor, but is not limited thereto. The electronic element 81 may be an IC element other than a field effect transistor or a resistor. The electronic element 81 may also include a field effect transistor and another electronic element such as a resistor.

[0047] The present technology can be configured as follows.

[0048] (1) A rotor that rotates about a rotation axis; A stator disposed around the rotor; A cylinder that covers the stator and is open on one side in the axial direction along the rotation axis. A resin sealing member having a portion; A circuit board accommodated in the cylindrical portion; a cover member that covers the cylindrical portion from the one side and includes a heat dissipation member made of a metal plate-shaped member; a potting member provided on the one side of the heat dissipation member; having the heat dissipation member includes a first surface on the one side, a recess that is recessed toward the other side in the axial direction, and a contact portion on a second surface on the other side in the axial direction, the contact portion being in contact with the circuit board; The motor is characterized in that the potting member is provided in the recess.

[0049] (2) The motor according to (1), further comprising a heat transfer member disposed between the contact portion and the circuit board.

[0050] (3) The motor according to (2), wherein the heat transfer member is elastically deformed between the contact portion and the circuit board.

[0051] (4) the circuit board includes an electronic element on the one surface, The motor according to (2) or (3), wherein the heat transfer member is in contact with the electronic element.

[0052] (5) The motor according to (4), wherein the electronic element is a field effect transistor.

[0053] (6) the heat dissipation member includes a protrusion protruding to the other side at a position on the second surface that overlaps with the recess in the axial direction, The motor according to any one of (1) to (5), wherein the protrusion is the contact portion.

[0054] (7) A motor according to any one of (1) to (6), an impeller that is rotated by the motor; A pump device comprising: [Explanation of symbols]

[0055] Reference Signs List 1...pump device, 2...case, 3...motor, 4...impeller, 5...rotor, 6...stator, 7...housing, 8...circuit board, 9...cover member, 10...magnet, 11...support shaft, 12...plate member, 15...heat transfer member, 18...potting member, 20...pump chamber, 21...suction pipe, 21a...suction port, 22...discharge pipe, 22a...discharge port, 23...opposing wall, 24...side wall, 41...first plate, 42...blade portion, 43...second plate, 51...holder, 52...small diameter portion, 53...contact portion, 54...large diameter portion, 56...bearing, 61...suction Theta core, 62...insulator, 63...coil, 70...resin sealing member, 71...first partition wall portion, 72...second partition wall portion, 73...third partition wall portion, 73a...hole portion, 74...tubular portion, 75...flange portion, 76...connector housing, 78...mounting portion, 79...fixing portion, 81...electronic element, 82...connector pin, 83...projection portion, 91...frame member, 91a...opening portion, 92...heat dissipation member, 93...sealing member, 94...welded portion, 612...tubular portion, 810...surface, 911...annular portion, 912...tubular portion, 913...flange portion, 917...projection portion, 917a...crimping portion, 921...shielding portion, 921a...first surface, 921b...second surface, 922...circumferential wall portion, 923...flange portion, 924...recess, 925...recess, 926...protrusion, 927...contact portion, 928...notch portion, 951...protrusion for welding, 952...recess for welding, L...rotation axis.

Claims

1. A rotor that rotates about a rotation axis; A stator disposed around the rotor; a resin sealing member that covers the stator and has a cylindrical portion that opens on one side in an axial direction along a rotation axis; A circuit board accommodated in the cylindrical portion; a cover member that covers the cylindrical portion from the one side and includes a heat dissipation member made of a metal plate-shaped member; a potting member provided on the one side of the heat dissipation member; having the heat dissipation member includes a first surface on the one side, a recess that is recessed toward the other side in the axial direction, and a contact portion on a second surface on the other side in the axial direction, the contact portion being in contact with the circuit board; The motor is characterized in that the potting member is provided in the recess.

2. 2. The motor according to claim 1, further comprising a heat transfer member disposed between the contact portion and the circuit board.

3. The motor according to claim 2 , wherein the heat transfer member is elastically deformed between the contact portion and the circuit board.

4. the circuit board includes an electronic element on the one surface, 4. The motor according to claim 2, wherein the heat transfer member is in contact with the electronic element.

5. 5. The motor according to claim 4, wherein the electronic element is a field effect transistor.

6. the heat dissipation member includes a protrusion that protrudes toward the other side at a position on the second surface that overlaps with the recess in the axial direction, The motor according to claim 1 , wherein the protrusion is the contact portion.

7. A motor according to claim 1; an impeller that is rotated by the motor; A pump device comprising:

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