Motor

Abstract

The motor (10) has a sheet-shaped gasket (16) for sealing between a stator core (12) and an encoder (14). The gasket (16) has a first portion (24) having a structure including a metal plate (MP) and a sealing member (SM) covering the metal plate (MP), the first portion being arranged between at least an end surface (12FA) on one end side of the stator core (12) and the encoder (14); and a second portion (26) having a structure without the metal plate (MP) but including the sealing member (SM), the second portion extending inward from the first portion (24) and contacting the protrusion (22).

Description

Technical Field

[0001] The invention relates to an electric motor. Background Art

[0002] Japanese Patent Publication No. 2019-009885 discloses a motor having: a stator core (motor housing); an encoder provided on one end of the stator core; and a sheet-shaped gasket (sealing component) that seals between the stator core and the encoder.

[0003] The encoder includes a housing (outer case) in which a detection element for detecting the rotation angle of a rotating shaft of a rotor, a bearing for supporting the rotating shaft of the rotor, and the like are accommodated.

[0004] However, a portion of the bearing or the like in the encoder protrudes toward the through hole of the stator core on which the rotor is arranged. That is, the encoder has a protrusion that protrudes toward the through hole of the stator core. When a gap is formed between the protrusion and the stator core, there is a concern that the protrusion may contact the stator core due to vibration or the like. Summary of the invention

[0005] Therefore, an object of the present invention is to provide a motor capable of suppressing a change in the relative position between a stator core and an encoder.

[0006] The present invention is a motor comprising: a stator core having a through hole for configuring a rotor; an encoder, which is arranged on one end side of the stator core and has a protrusion protruding toward the through hole; and a sheet-like gasket, which has a connecting hole connected to the through hole and seals the stator core and the encoder, the gasket having: a first portion, which is a structure including a metal plate and a sealing component covering the metal plate, the first portion being at least configured between an end surface of one end side of the stator core and the encoder; and a second portion, which is a structure without the metal plate but including the sealing component, the second portion extending inwardly from the first portion and contacting the protrusion.

[0007] According to the aspect of the present invention, the change in the relative position between the stator core and the encoder can be suppressed by the washer.

[0008] The above-mentioned objects, features and advantages can be easily understood from the following description of the embodiments described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is an exploded perspective view showing a part of the motor.

[0010] Figure 2 It is a figure which shows a gasket.

[0011] Figure 3 is a cross-sectional view of the motor including the periphery of the gasket.

[0012] Figure 4 It is a figure which shows the gasket of modification example 1.

[0013] Figure 5 This is a diagram showing an encoder according to variation 2.

[0014] Figure 6 This is a diagram showing an encoder according to variation 3. DETAILED DESCRIPTION

[0015] Hereinafter, the present invention will be described in detail by listing preferred embodiments and referring to the drawings.

[0016] [Implementation Method]

[0017] use Figure 1 The motor 10 according to the present embodiment will be described. Figure 1 1 is an exploded perspective view showing a part of the motor 10 . The motor 10 includes a stator core 12 , an encoder 14 provided on one end of the stator core 12 , and a gasket 16 that seals between the stator core 12 and the encoder 14 .

[0018] The stator core 12 has a through hole 12H for configuring the rotor and a plurality of bolt holes BH. The through hole 12H extends from an end face 12FA at one end of the stator core 12 to an end face 12FB at the other end of the stator core 12 along the central axis AX of the stator core 12. Each of the plurality of bolt holes BH extends from the end face 12FA at one end of the stator core 12 toward the end face 12FB at the other end of the stator core 12. In addition, the central axis AX of the stator core 12 coincides with the rotation axis of the motor 10.

[0019] The encoder 14 includes a detection element for detecting the rotation angle of the rotating shaft of the rotor, and a housing 18 that accommodates a bearing that supports the rotating shaft of the rotor. A plate-shaped flange 20 is formed on the housing 18, and the flange 20 extends outward from the housing 18 along the end surface 12FA of the stator core 12. The flange 20 has a plurality of bolt insertion holes 20H, and the bolt threads of the bolts BT that are engaged with the bolt holes BH of the stator core 12 can be inserted through the plurality of bolt insertion holes 20H. The bolt threads of the bolts BT inserted through each of the plurality of bolt insertion holes 20H are engaged with the bolt holes BH of the stator core 12, and thereby the housing 18 is fixed to the end surface 12FA side of one end side of the stator core 12.

[0020] The encoder 14 has a protrusion 22 protruding from the housing 18 to the outside of the housing 18. The protrusion 22 may also include at least a portion of a bearing and a detection element accommodated in the housing 18. In a state where the housing 18 is fixed to the end surface 12FA of the stator core 12, the protrusion 22 protrudes toward the through hole 12H of the stator core 12. That is, in a state where the housing 18 is fixed to the end surface 12FA of the stator core 12, the protrusion 22 enters a position closer to the inside of the through hole 12H than the opening surface of the through hole 12H on one end side of the stator core 12.

[0021] use Figure 2 The gasket 16 will be described. Figure 2 1 is a diagram showing a washer 16. The washer 16 is formed in a sheet shape and has a connecting hole 16H connected to the through hole 12H of the stator core 12. When the washer 16 is arranged between the stator core 12 and the encoder 14, the connecting hole 16H is arranged along the central axis AX ( Figure 1 ) is extended. The washer 16 has a first portion 24 on the outer circumference and a second portion 26 on the inner circumference. The first portion 24 and the second portion 26 are connected without a gap. The first portion 24 has a plurality of bolt insertion holes 24H through which bolt threads of the bolts BT can be inserted.

[0022] use Figure 3 The gasket 16 will be described in further detail. Figure 3 1 is a cross-sectional view of the motor 10 including the periphery of the gasket 16. Figure 3 In FIG. 1 , only the washer 16 and the stator core 12 are shown in a cross section along the central axis AX (rotation axis of the motor 10 ) of the stator core 12 .

[0023] The first portion 24 is a structure including a metal plate MP and a sealing member SM covering the metal plate MP. As the sealing member SM, natural rubber, synthetic rubber, etc. can be listed. In addition, the metal plate MP and the sealing member SM can be fixed with an adhesive. In addition, the surface of the sealing member SM can be coated with a coating. The first portion 24 is arranged at least between the end face 12FA of the stator core 12 and the flange 20 of the encoder 14. In addition, the first portion 24 can extend slightly from the end face 12FA of the stator core 12 to the inside (through hole 12H side).

[0024] The second portion 26 is a structure without the metal plate MP but including the sealing member SM, and extends inward from the first portion 24. That is, the second portion 26 is a portion located further inward than the end surface on the inner side (the through hole 12H side of the stator core 12) of the metal plate MP. The second portion 26 may also be formed by extending the sealing member SM of the first portion 24 inward. In addition, the surface of the sealing member SM in the second portion 26 may also be coated with a coating, similar to the first portion 24.

[0025] The second portion 26 extending inward from the first portion 24 contacts the protrusion 22 of the encoder 14. The second portion 26 may contact the side surface of the protrusion 22 along the circumferential direction of the stator core 12 without a gap, or may have a gap around the side surface of the protrusion 22. The second portion 26 may contact the protrusion 22 while pressing the protrusion 22.

[0026] Thus, the gasket 16 of the present embodiment includes: a first portion 24 having a structure including a metal plate MP and a sealing member SM covering the metal plate MP; and a second portion 26 extending inward from the first portion 24. The second portion 26 has a structure including a sealing member SM without the metal plate MP, and contacts the protrusion 22 of the encoder 14.

[0027] Thus, the washer 16 can suppress the change in the relative position between the stator core 12 and the encoder 14. Therefore, it is possible to prevent the protrusion 22 of the encoder 14 from coming into contact with the stator core 12 due to vibration or the like applied to the motor 10.

[0028] Furthermore, when the protrusion 22 of the encoder 14 is mounted to the rotor disposed in the through hole 12H of the stator core 12 with the washer 16 mounted on the end surface 12FA of the stator core 12, the second portion 26 of the washer 16 can support the protrusion 22. Therefore, when the motor 10 is assembled, the protrusion 22 can be prevented from falling off from a predetermined position toward the rotor side.

[0029] [Variation]

[0030] The above-mentioned embodiment may be modified as follows.

[0031] (Variant 1)

[0032] use Figure 4 Modification 1 is described. In this modification, a plurality of cutouts 30 are provided at intervals in the second portion 26 of the washer 16 in the circumferential direction of the central axis AX of the stator core 12 . That is, the plurality of cutouts 30 are provided at intervals in the second portion 26 in the circumferential direction of the stator core 12 .

[0033] Therefore, when the encoder 14 is mounted on the rotating shaft of the rotor disposed in the through hole 12H of the stator core 12 , the phase of the encoder 14 can be positioned to match the phase of the rotor, resulting in the motor 10 that can appropriately detect the rotation angle.

[0034] (Variant 2)

[0035] use Figure 5Modification 2 will be described. In this modification, the shape of the stator core 12 is different from that of the above-described embodiment. The shape of the end portion 26E of the second portion 26 of the washer 16 is different from that of the above-described embodiment.

[0036] The end portion 26E of the second portion 26 is an end portion on the central axis AX side of the stator core 12 and has elasticity. Figure 5 As shown by the double-dotted chain line, when observing the cross section along the direction of the central axis AX of the stator core 12, the end 26E of the second portion 26 is formed into an arc shape having a diameter larger than the thickness T of the first portion 24 in a non-contact state with the protrusion 22 of the encoder 14. The thickness T of the first portion 24 is the length of the first portion 24 along the direction of the central axis AX of the stator core 12.

[0037] In addition, the second portion 26 has flexibility. Therefore, the end portion 26E of the second portion 26 is in contact with the protrusion 22 of the encoder 14, and the end portion 26E of the second portion 26 is in contact with the protrusion 22 of the encoder 14. Figure 5 The end portion 26E of the second portion 26 is deformed as shown by the solid line, and the cross section along the direction of the central axis AX of the stator core 12 does not have an arc shape.

[0038] In this modification, the end face 12FA at one end of the stator core 12 has a step. The end face 12FA on the side with the lower step contacts a part of the end 26E of the second portion 26. Thus, the change in the relative position of the stator core 12 and the encoder 14 can be further suppressed. In addition, the sealing performance of the gasket 16 that prevents water, dust, etc. from entering the interior can be improved.

[0039] In addition, the step of the end surface 12FA on one end side of the stator core 12 is formed by providing a convex portion 12X protruding from the inner wall side of the stator core 12 toward the central axis AX of the stator core 12 on the stator core 12. The convex portion 12X may be provided over the entire periphery of the inner wall surface along the circumference of the stator core 12, or may be provided over a portion of the periphery of the inner wall surface. In addition, the convex portion 12X may extend to the end surface 12FB ( Figure 1 ), and may not extend to the end face 12FB.

[0040] (Variant 3)

[0041] use Figure 6 Modification 3 is described. In this modification, a groove 22G is formed in the protrusion 22 of the encoder 14. The groove 22G may be formed entirely around the side surface of the protrusion 22 along the circumferential direction of the stator core 12, or may be formed on a portion around the side surface of the protrusion 22. The top end portion of the second portion 26 of the encoder 14 enters the groove 22G. The top end portion may also be an end portion 26E having an arc shape in a cross section along the direction of the central axis AX of the stator core 12 as in Modification 2.

[0042] Thus, by forming the groove 22G into which the tip portion of the second portion 26 of the encoder 14 enters in the protruding portion 22 of the encoder 14 , it is possible to suppress a change in the relative position of the stator core 12 and the encoder 14 .

[0043] (Variant 4)

[0044] The above-described embodiments and modifications may be arbitrarily combined within a range where no contradiction occurs.

[0045] 〔Technical Thought〕

[0046] The present invention will be described below as a technical idea that can be obtained from the above-mentioned embodiment and modified examples.

[0047] The present invention is a motor 10, which includes: a stator core 12, the stator core 12 having a through hole 12H for arranging a rotor; an encoder 14, the encoder 14 being provided at one end side of the stator core 12 and having a protrusion 22 protruding toward the through hole 12H; and a sheet-like gasket 16, the gasket 16 having a connecting hole 16H communicating with the through hole 12H and sealing between the stator core 12 and the encoder 14. The gasket 16 includes: a first portion 24, the first portion 24 being a structure including a metal plate MP and a sealing member SM covering the metal plate MP, the first portion 24 being arranged at least between an end surface 12FA at one end side of the stator core 12 and the encoder 14; and a second portion 26, the second portion 26 being a structure including a sealing member SM without the metal plate MP, the second portion extending inward from the first portion 24 and contacting the protrusion 22.

[0048] Thus, the washer 16 can be used to suppress a change in the relative position between the stator core 12 and the encoder 14 .

[0049] The second portion 26 may be in contact with the side surface of the protruding portion 22 along the circumferential direction of the stator core 12 without a gap. Thus, the change in the relative position between the stator core 12 and the encoder 14 can be further suppressed.

[0050] The second portion 26 may also be provided with a plurality of cutouts 30 spaced apart along the circumferential direction of the stator core 12. Thus, when the encoder 14 is mounted on the rotating shaft of the rotor disposed in the through hole 12H of the stator core 12, the phase of the encoder 14 can be positioned to match the phase of the rotor. Therefore, the motor 10 that can properly detect the rotation angle can be obtained.

[0051] When observing the cross section along the direction of the central axis AX of the stator core 12, the end 26E of the second portion 26 is formed in the shape of an arc having a diameter larger than the thickness T of the first portion 24 in a state of non-contact with the protrusion 22, and the end face 12FA on one end side of the stator core 12 has a step, and the end face 12FA on the side with the lower step may also contact a part of the end 26E of the second portion 26. Thus, the change in the relative position of the stator core 12 and the encoder 14 can be further suppressed. In addition, the sealing performance of the gasket 16 can be improved.

[0052] A groove 22G into which the tip portion of the second portion 26 enters may be formed in the protrusion 22. This can further suppress a change in the relative position between the stator core 12 and the encoder 14.

Claims

1. A motor having: A stator core having a through hole for the rotor to be arranged; an encoder provided on one end side of the stator core and having a protrusion protruding toward the through hole; as well as a sheet-shaped gasket having a communicating hole communicating with the through hole and sealing between the stator core and the encoder, It is characterized in that The gasket comprises: a first portion, which is a structure including a metal plate and a sealing component covering the metal plate, and the first portion is arranged at least between the end surface of one end side of the stator core and the encoder; and a second portion, which is a structure without the metal plate but including the sealing component, and the second portion extends inward from the first portion and contacts the protrusion.

2. The motor according to claim 1, characterized in that The second portion is in contact with the periphery of the side surface of the protrusion along the circumferential direction of the stator core without a gap.

3. The motor according to claim 1, characterized in that A plurality of cutouts are provided at the second portion at intervals along the circumferential direction of the stator core.

4. The motor according to any one of claims 1 to 3, characterized in that: When observing a cross section along the central axis direction of the stator core, the end of the second portion is formed in a circular arc shape having a diameter larger than the thickness of the first portion in a state of not contacting the protrusion. The end surface of one end side of the stator core has a step, and the end surface on the side where the step is lower contacts a part of the end portion of the second portion.

5. The motor according to any one of claims 1 to 3, characterized in that: The protruding portion has a groove formed therein into which the tip portion of the second portion enters.

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