Resolver mounting structure

Abstract

[Problem] To provide a resolver attachment structure with which an attachment fitting is resistant to deformation, in a structure for attaching a resolver to a housing. [Solution] A stator 3 is provided with a stator core 6, a stator winding 8a wound through an insulator 9 provided on the stator core 6, and a terminal block 10 disposed on the radially outer side of the stator core 6. The stator core 6 has an end portion that projects out in an axial direction from an opening portion of a housing 5, and is attached to the housing 5 by means of an attachment fitting 20 that abuts an end surface of the end portion. The attachment fitting 20 is provided with: a C-shaped annular portion 21; a linking portion 22 provided between the two ends of the annular portion 21; and a bent portion 23 which projects upward in the axial direction from an inner circumferential edge portion of the annular portion 21. The bent portion 23 abuts the end surface of the stator core 6, and the linking portion 22 is provided with a relief portion 22b extending to a position avoiding the terminal block 10.

Description

Technical Field

[0005] ,

[0001] The present invention relates to an attachment structure of a resolver to a housing, and particularly relates to a technique for suppressing deformation of an attachment member.

Background Art

[0002] Conventionally, a resolver is known as a means for detecting the rotation angle of a motor or the like. The resolver includes a rotor fixed to a rotation shaft of a motor or the like and rotating together with the rotation shaft, and a stator fixed to a housing and disposed outside the rotor. When the rotor rotates, the dimension of the air gap formed between the rotor and the stator changes with the rotation of the rotor, and an output corresponding to this change occurs in a detection coil disposed on the stator side. Based on this output, the rotation angle of the rotor is detected.

[0003] As a structure for fixing a resolver to an attachment object, a structure has been proposed in which the stator of the resolver is housed in an opening of a housing and the stator is attached to the housing by an attachment fitting (see, for example, Patent Document 1). Referring to FIG. 13, which is a reproduction of FIG. 7 of Patent Document 1, the attachment fitting 17 has a C-shaped shape in which a part of an annular portion is cut out, has a plurality of bolt insertion holes 17a for inserting bolts 14 in the circumferential direction, and is provided with a bent portion 17c in the axial direction along the inner peripheral edge, so that the stator 3 is pressed against the housing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The C-shaped mounting bracket 17 described in Patent Document 1 is manufactured by press-forming a plate made of metal material, as described in paragraph 0025 of Patent Document 1. However, if the thickness of the mounting bracket 17 is thin, it has a C-shape with a part of the annular portion cut out, so there is a risk that the mounting bracket 17 may deform when held by hand. If the mounting bracket 17 deforms, problems may arise such as a shift in its relative position with respect to the stator 3 or a shift in the position of the bolt insertion hole 17a, causing problems when inserting the bolt 14.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a resolver mounting structure that makes it difficult for the mounting bracket to deform when a resolver is attached to a housing. [Means for solving the problem]

[0007] The present invention relates to a resolver stator mounting structure for mounting the stator of a resolver to an opening in a housing, wherein the stator comprises a stator core, stator windings wound around the stator core via an insulator provided on the stator core, and a terminal block positioned radially outside the stator core, wherein one end of the stator core in the axial direction protrudes axially from the opening in the housing and is attached to the housing by a mounting member that abuts against the end face of the end, wherein the mounting member comprises an annular portion extending in a range that does not include a part of the entire circumference, connecting portions provided at both ends of the annular portion, and a bent portion at the inner peripheral edge of the annular portion that protrudes toward the one side in the axial direction, wherein the bent portion abuts against the end face of the stator core, and the connecting portion has a relief portion that extends to a position avoiding the terminal block.

[0008] In the resolver stator mounting structure described above, the relief portion prevents contact between the mounting member and the terminal block, and since the annular portion and the relief portion of the mounting member are continuous, the mounting member has strong resistance to deformation even if its plate thickness is thin. Therefore, deformation of the mounting member is unlikely to occur even when handling it by hand. [Effects of the Invention]

[0009] According to the present invention, since the mounting member has a structure that is difficult to deform even when held by hand, the relative position between the mounting member and the stator, as well as the position of the bolt insertion holes, can be precisely aligned. [Brief explanation of the drawing]

[0010] [Figure 1] This is a plan view showing the state in which a mounting member is attached to the stator of a VR type resolver according to the first embodiment of the present invention. [Figure 2] This is a cross-sectional view taken along line II-II in Figure 1. [Figure 3] This is a cross-sectional view showing the mounting member shown in Figure 1 attached to the housing. [Figure 4] Figure 1 is a perspective view showing the mounting member. [Figure 5] Figure 4 is a plan view of the mounting member. [Figure 6] Figure 5 is a cross-sectional view of the mounting member. [Figure 7] This is a perspective view showing the state in which a mounting member is attached to the stator of a VR type resolver according to a second embodiment of the present invention. [Figure 8] This is a perspective view showing Figure 7 reversed. [Figure 9] Figure 7 is a perspective view showing the mounting member. [Figure 10] (A) is a plan view of the mounting member, and (B) is a side cross-sectional view. [Figure 11] This is a cross-sectional view showing the state in which a mounting member is attached to the stator of a VR type resolver according to the third embodiment of the present invention. [Figure 12] (A) is a plan view showing the mounting member shown in Figure 11, and (B) is a side cross-sectional view thereof. [Figure 13] This is a plan view showing a conventional mounting member as described in Patent Document 1. [Modes for carrying out the invention]

[0011] [1] First Embodiment 1. Configuration of the resolver Fig. 1 shows the resolver 1 of the first embodiment of the present invention as viewed from the axial direction. The resolver 1 is a VR (Variable Reluctance) type resolver. The resolver 1 has a rotor 2 and a stator 3. The rotor 2 is fixed to the output shaft 4 of a motor (not shown). The rotor 2 has a non-circular shape with a plurality of protrusions protruding radially outward when viewed from the axial direction. The rotor 2 has a structure in which a plurality of thin plate-shaped rotor cores are stacked in the axial direction.

[0012] The thin plate-shaped rotor core constituting the rotor 2 is manufactured by pressing a plate made of an electromagnetic steel sheet into the illustrated shape. The plurality of rotor cores are stacked in the axial direction and fixed by caulking, thereby constituting the rotor 2. The stator 3 is disposed outside the rotor 2 and fixed to the housing 5. A gap is provided between the rotor 2 and the stator 3, and the rotor 2 can rotate inside the stator 3. The housing 5 is a member to which the resolver 1 is to be attached, and a screw hole 5d for fixing the resolver 1 is provided (see Fig. 3). A female screw is formed on the inner circumference of the screw hole 5d, and it has a structure that engages with the bolt 14.

[0013] The stator 3 has a stator core 6. The stator core 6 has a structure in which a plurality of thin plate-shaped cores are stacked in the axial direction. The thin plate-shaped core has a shape having an annular core back 7 and a plurality of teeth 8 protruding radially inward from the core back 7. The core is manufactured by pressing a plate made of an electromagnetic steel sheet. By stacking a plurality of these cores in the axial direction and fixing them by caulking, the stator core 6 is obtained.

[0014] As shown in Fig. 2, a pair of insulators 9 are mounted on both axial sides of the stator core 6. The insulators 9 are made of resin, and stator windings 8a are wound around each tooth 8 via the insulators 9. The stator winding 8a is composed of an exciting winding and an output winding. The output winding is composed of a sin-phase winding that outputs a sin signal and a cos-phase winding that outputs a cos signal with a 90° phase difference from the sin signal. The winding terminals 8b of each of the exciting winding and the output winding are wound around one end of a terminal pin 11 implanted in a terminal block 10 integrally formed with the insulator 9 and are electrically connected to the terminal pin 11. In Fig. 1, reference numeral 13 is a lead wire, and the lead wire 13 is connected to the other end of each terminal pin 11. Note that the stator core 6 may be used as an insert material and integrally formed with the insulator 9 and the terminal block 10 by injection molding of resin.

[0015] A terminal cover 12 is mounted on the terminal block 10. The terminal cover 12 includes a box-shaped main body portion 12a that covers the upper, left and right, and rear sides (the right side in Fig. 2) of the terminal pin 11, and a tail portion 12b that is formed thinner than the main body portion 12a. This terminal cover 12 prevents contact with other components, particularly on the upper side, and protects the terminal pin 11 and the like.

[0016] 2. Structure of the Resolver Mounting Structure Hereinafter, the structure for fixing the resolver 1 to the housing 5 will be described. First, as shown in Fig. 3, an opening 5a for accommodating the resolver 1 is formed in the housing 5. The opening 5a is substantially circular when viewed from the axial direction and has a cylindrical cavity shape.

[0017] With the stator 3 housed in the opening 5a, the outer circumferential surface of the stator core 6 (see Figure 2) fits into the inner circumferential surface of the opening 5a. In this state, the edge portion of the axial end of the stator core 6 contacts the stepped portion 5b provided on the inner circumferential surface of the opening 5a, thereby determining the axial position of the stator 3 (stator core 6) relative to the housing 5. With the stator 3 housed in the opening 5a of the housing 5, the upper end surface of the stator core 6 protrudes from the opening 5a. The stator core 6 is then pressed against and fixed to the housing 5 by a mounting bracket (mounting member) 20.

[0018] As shown in Figures 4 and 5, the mounting bracket 20 is annular in shape and is manufactured by press-forming a plate made of a metal material. A non-magnetic metal material (for example, a non-magnetic stainless steel sheet) is preferred as the metal material, but a magnetic metal material (for example, a cold-rolled steel sheet) may also be used as long as it does not significantly affect the characteristics of the resolver. The mounting bracket 20 comprises an annular portion 21 that is roughly C-shaped and connecting portions 22 that are installed at both ends of the annular portion 21. The connecting portion 22 consists of arm portions 22a that protrude radially outward from both ends of the annular portion 21 and a gate-shaped relief portion 22b that is bent at a right angle at the tip of the arm portions 22a. The central part of the relief portion 22b is positioned above the tail portion 12b of the terminal cover 12 and does not come into contact with the tail portion 12b. Furthermore, the angle between the relief portion 22b and the arm portion 22a is not limited to 90°; the angle is arbitrary as long as contact with the terminal cover 12 can be avoided.

[0019] A bent portion 23 is formed on the inner peripheral edge of the annular portion 21, shifted upward in the axial direction. As shown in Figure 6, the bent portion 23 consists of a tapered portion 23a that rises tapered from the annular portion 21 and a flat portion 23b parallel to the annular portion 21. In addition, multiple (three in this example) flange portions 24 are formed at equal intervals in the circumferential direction on the outer peripheral edge of the annular portion 21, projecting radially outward. Bolt insertion holes 24a are formed in these flange portions 24 for inserting bolts 14 (see Figure 3). Here, the bolt insertion holes 24a may be elongated or have a larger diameter than the threaded portion of the bolt 14 to absorb positional errors of the threaded holes 5d (see Figure 3). Note that the number and arrangement of the flange portions 24 are not limited to three, as the bolt insertion holes 24a coincide with the arrangement of the threaded holes 5d.

[0020] With the stator 3 housed in the opening 5a of the housing 5 (as shown in Figure 3), the mounting bracket 20 is pressed against the mounting surface 5e of the housing 5 from axially above, and the bolt 14 is then screwed through the bolt insertion hole 24a into the screw hole 5d. The bolt 14 is then tightened, thereby pressing and fixing the stator 3 to the housing 5 with the mounting bracket 20.

[0021] Furthermore, when the stator 3 is fixed to the opening 5a of the housing 5, the axial end face of the stator core 6 protrudes beyond the mounting surface 5e of the housing 5. The distance from the lower surface of the flat portion 23b of the bent portion 23 of the mounting bracket 20 to the mounting surface 5e of the housing 5 is set to be slightly shorter than the protruding axial end face of the stator core 6, and the end face of the stator core 6 that protrudes from the mounting surface 5e is pressed in the axial direction by the flat portion 23b. With this structure, no axial play occurs in the stator core 6.

[0022] Furthermore, when the mounting bracket 20 is attached to the housing 5, the arms 22a of the mounting bracket 20 are positioned on both sides of the terminal block 10, and the center of the relief portion 22b is positioned above the tail portion 12b of the terminal cover 12. In this way, the mounting bracket 20 is structured so that it does not come into contact with the terminal block 10 or the terminal cover 12.

[0023] 3. Effects In the resolver mounting structure described above, the relief portion 22b prevents contact between the mounting bracket 20 and the terminal block 10, and since the annular portion 21 of the mounting bracket 20 and the relief portion 22b are continuous, the mounting bracket 20 has strong resistance to deformation even if its plate thickness is thin. Therefore, even when the mounting bracket 20 is held by hand during work, deformation of the mounting bracket 20 is unlikely to occur, and the relative position of the mounting bracket 20 and the stator core 6, as well as the position of the bolt insertion holes 24a, can be accurately aligned.

[0024] Furthermore, since the relief portion 22b is positioned above the terminal cover 12, the mounting bracket 20 can avoid contact with the terminal block 10 and the terminal cover 12 without extending the mounting bracket 20 radially outward from the terminal block 10, thus making the configuration more compact.

[0025] Furthermore, since the relief portion 22b is not located above the stator winding 8a, it can accommodate situations where there is no free space above the stator winding 8a (for example, when the motor rotor is positioned close to the stator winding 8a).

[0026] 4. Example of changes The present invention is not limited to the above embodiments, and various modifications are possible as follows. i) In the above embodiment, a flange portion 24 is provided, but the width of the annular portion 21 may be increased and bolt insertion holes may be formed therein.

[0027] ii) In the above embodiment, the relief portion 22b is bent at the tip of the arm portion 22a, but the two may be connected by welding. For example, the relief portion 22b may be formed in an L shape in a side view, and the base of the relief portion 22b may be spot welded to the arm portion 22a, for example.

[0028] iii) In the above embodiment, the entire upper side of the terminal block 10 is covered by the terminal cover 12, but it is also possible to configure it so that only the terminal pins 11 are covered by the terminal cover 10. Alternatively, it is also possible to configure it so that the terminal cover 12 is not attached. In that case, the relief portion 22b is configured to avoid contact with the terminal block 10.

[0029] iv) In the above embodiment, the annular portion 21 of the mounting bracket 20 is configured to be approximately C-shaped in an axial view, but the contour shape of the outer circumference of the annular portion 21 is arbitrary. For example, it can be a polygonal shape such as a square or hexagon, or a shape like the rotor 2 shown in Figure 1. v) The arm portion 22a may be omitted. In this case, the relief portion 22b rises immediately from both ends of the annular portion 21 and is positioned on top of the main body portion 12a. vi) The shape of the relief section 22b is not limited to a gate shape, but can be any shape such as an arch shape.

[0030] [2] Second embodiment A second embodiment of the present invention will be described with reference to Figures 7 to 10. In the following description, components equivalent to those in the first embodiment will be denoted by the same reference numerals and their descriptions will be omitted.

[0031] The mounting bracket (mounting member) 30 comprises an annular portion 31 having a roughly C-shape and connecting portions 32 installed at both ends of the annular portion 31. The connecting portion 32 consists of arm portions 32a that protrude radially outward from both ends of the annular portion 31 and a first crossbar member 32b installed at the tip of the arm portions 32a. The first crossbar member 32b is linear and positioned radially outward from the tail portion 12b of the terminal cover 12, and does not come into contact with the tail portion 12b.

[0032] A bent portion 33 is formed on the inner peripheral edge of the annular portion 31, shifted upward in the axial direction. The structure of the bent portion 33 is the same as that of the bent portion 23 shown in Figure 6, and as shown in Figure 10b, it consists of a tapered portion 33a that rises in a tapered shape from the annular portion 31 and a flat portion 33b parallel to the annular portion 31. In addition, multiple (three in this example) flange portions 34 that protrude radially outward are formed on the outer peripheral edge of the annular portion 31 at equal intervals in the circumferential direction. Bolt insertion holes 34a for inserting bolts 14 (see Figure 3) are formed in these flange portions 34. These flange portions 34, the annular portion 31, and the connecting portion 32 are formed on substantially the same plane.

[0033] Such mounting brackets 30 are used to attach the stator 3 to the housing 5 in the same manner as in the first embodiment. Furthermore, in the resolver stator mounting structure described above, not only are the same functions and effects as in the first embodiment obtained, but the configuration of the connecting portion 32 of the mounting bracket 30 is simpler, which reduces manufacturing costs. In addition, this second embodiment has the following advantages compared to the first embodiment.

[0034] The stator of the VR type resolver with the mounting bracket 20 attached, as shown in Figure 1, is assembled in the following steps. a. The stator winding 8a is wound around the teeth 8 of the stator core 6, and the winding end 8b of the stator winding 8a is wrapped around one end of the terminal pin 11 for connection, and the connection is electrically made, for example, by TIG welding. b. After applying varnish to a designated area of ​​the stator winding 8a (up to the winding end 8b), the varnish is hardened by heating it in an oven, for example. c. After the varnish has hardened, the lead wire 13 is welded to the other end of the terminal pin 11 by resistance welding. d. Attach the terminal cover 12 to the terminal block 10. e. The mounting bracket 20 is attached to the outer surface of the stator core 6, a thermosetting adhesive is applied to a predetermined location on the mounting bracket 20, and then the adhesive is cured by heating it in an oven, for example.

[0035] Thus, in the first embodiment, two heating steps using an oven are required for the curing of the varnish and the adhesive. In contrast, in the second embodiment, if the mounting bracket 30 is attached to the outer surface of the stator core 6 before applying the varnish, the application of the varnish and the adhesive can be carried out almost simultaneously, allowing both to be cured with a single heating step using an oven.

[0036] [3] Third embodiment Figures 11 and 12 show a third embodiment of the present invention. The mounting bracket (mounting member) 40 comprises an annular portion 41 having a roughly C-shape and connecting portions (second crossbar members) 42 installed at both ends of the annular portion 41. The connecting portions 42 extend from both ends of the annular portion 41 along its extension trajectory with the same width and curvature as the flat outer edge of the annular portion 41. The connecting portions 42 are positioned axially below the terminal block 10 and do not come into contact with the terminal block 10. In other words, the connecting portions 42 constitute the relief portion of the present invention. The connecting portions 42 may also be straight.

[0037] A bent portion 43 is formed on the inner peripheral edge of the annular portion 41, shifted upward in the axial direction. The structure of the bent portion 43 is the same as that of the bent portion 23 shown in Figure 6, and as shown in Figure 12b, it consists of a tapered portion 43a that rises in a tapered shape from the annular portion 41 and a flat portion 43b parallel to the annular portion 41. In addition, multiple (three in this example) flange portions 44 that protrude radially outward are formed on the outer peripheral edge of the annular portion 41 at equal intervals in the circumferential direction. Bolt insertion holes 44a for inserting bolts 14 (see Figure 3) are formed in these flange portions 44. These flange portions 44, the annular portion 41 and the connecting portion 42 are formed on substantially the same plane.

[0038] Such mounting brackets 40 are used to attach the stator 3 to the housing 5 in the same manner as in the first embodiment. Furthermore, in the resolver stator mounting structure described above, not only can the same functions and effects as in the second embodiment be obtained, but since the outer contour of the connecting portion 42 matches the outer contour of the annular portion 41, the configuration of the press die for forming the mounting bracket 40 can be simplified and the material cost of the mounting bracket 40 can be reduced. [Industrial applicability]

[0039] This invention can be used in a structure for fixing a resolver to a housing or the like. [Explanation of symbols]

[0040] 1…Resolver, 2…Rotor, 3…Stator, 4…Output shaft, 5…Housing, 5a…Opening, 5b…Stepped section, 5d…Screw hole, 5e…Mounting surface, 6…Stator core, 7…Core back, 8…Teeth, 8a…Stator winding, 8b…Winding terminal, 9…Insulator, 10…Terminal block, 11…Terminal pin, 12…Terminal cover, 12a…Main body, 12b…Tail section, 13…Lead wire, 20,30,40…Mounting bracket (mounting member), 21,31,41…Annular section, 22,32…Connecting section, 22a,32a…Arm section, 22b…Relief section, 23,33,43…Bent section, 24,34,44…Flange section, 24a,34a,44a…Bolt insertion hole, 32b…First crossbar member, 42…Connecting section (second crossbar member).

Claims

1. A resolver stator mounting structure for attaching the resolver stator to the opening of the housing, The stator comprises a stator core, stator windings wound around the stator core via an insulator, and a terminal block positioned radially outward from the stator core. The stator core is attached to the housing by a mounting member that abuts against the end face of the axial end, with one end of the stator core protruding axially from the opening of the housing. The mounting member comprises an annular portion extending over a range that does not include a part of the entire circumference, connecting portions installed at both ends of the annular portion, and a bent portion projecting toward one side in the axial direction at the inner peripheral edge of the annular portion. The bent portion abuts against the end face of the stator core, The connecting portion is a resolver stator mounting structure that includes a relief portion extending to a position that avoids the terminal block.

2. The resolver stator mounting structure according to claim 1, wherein the relief portion is bent near both ends of the annular portion and positioned on one side of the terminal block in the axial direction.

3. The relief portion comprises an arm portion extending radially outward from near both ends of the annular portion, and a first cross member mounted on the tip of the arm portion, wherein the first cross member is located radially outward of the terminal block, as described in claim 1.

4. The relief portion is a second crossbar member installed at both ends of the annular portion, and the second crossbar member is located on the other axial side of the terminal block, as described in claim 1, for the resolver stator mounting structure.

5. The resolver stator mounting structure according to claim 4, wherein the second support member extends along the extension trajectory of the flat outer edge of the annular portion with the same width and curvature as the outer edge of the annular portion.

6. The resolver stator mounting structure according to claim 4, wherein the second support member is linear.

7. The stator mounting structure for a resolver according to any one of claims 3 to 6, wherein the mounting member comprises a plurality of flange portions projecting radially outward from the outer peripheral edge of the annular portion, and the annular portion, the plurality of flange portions, and the connecting portion are formed in substantially the same plane.

8. The resolver stator mounting structure according to claim 7, wherein the plurality of flange portions have bolt insertion holes.

9. The stator mounting structure for a resolver according to any one of claims 1 to 8, wherein the connecting portion comprises arm portions that protrude radially outward from both ends of the annular portion, and the relief portion is bent at the end of the arm portion to one side in the axial direction to form a gate shape.

10. The stator mounting structure for a resolver according to any one of claims 1 to 9, wherein the terminal block is provided with a plurality of terminal pins for interlocking and connecting the ends of the stator windings, and a terminal cover for protecting the terminal pins is attached to the terminal block.

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