Angle sensor

Abstract

Provided is an angle sensor capable of firmly attaching a stator core to a housing without application of a load to the stator core.　This resolver comprises: a housing (200) having an opening; a stator stack (110) accommodated in the opening; a rotor corresponding to the stator stack (110); an insulator (150) covering the stator stack (110); a coil (157) wound around the insulator (150); and a cover (300) covering the coil (157). In the rotation axis direction, one surface of the stator stack (110) is in contact with a step (222) of the housing (200), and a top surface (113) of the stator stack (110) is in contact with the cover (300). A top surface (230a) of a base (230) forming the opening faces the cover (300) in the rotation axis direction with a gap (L) therebetween.

Description

Angle sensor

[0001] The present invention relates to an angle sensor such as a resolver, and particularly to a technique for firmly attaching a stator stack to a housing.

[0002] Conventionally, a resolver is known as an angle sensor for detecting the rotation angle of a rotating electrical machine such as a motor or a generator. The resolver includes a stator and a rotor disposed opposite to the inside of the stator. The stator includes a stator stack having a plurality of teeth protruding from an annular core back toward the inner peripheral side, and an insulator covering the stator stack. A terminal block in which terminals are insert-molded is integrally molded on the insulator.

[0003] In the resolver as described above, a cover for covering the stator and the terminal block is attached. For example, in the resolver described in Patent Document 1, the stator core (stator stack) 34 of the resolver stator 33 is fitted into the fixing ring 41a of the magnetic shield 40, and the two are fixed with an adhesive or the like.

[0004] Japanese Patent Application Laid-Open No. 2012-157180

[0005] However, in the method of fixing the stator stack to the fixing ring with an adhesive, there is a problem that the number of steps such as adhesion increases. On the other hand, in the method of press-fitting the stator stack into the fixing ring, there is a risk that the angle detection accuracy may decrease due to the deformation of the stator stack.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide an angle sensor capable of firmly attaching a stator stack to a housing.

[0007] The present invention relates to an angle sensor comprising a housing having an opening, a status tack housed in the opening, a rotor corresponding to the status tack, an insulating member covering the status tack, a conductor wound around the insulating member, and a cover covering the conductor, wherein, in the rotation axis direction of the rotor, one surface of the status tack is in contact with the housing, the other surface of the status tack is in contact with the cover, and the top surface of the wall forming the opening faces the cover with a gap in the rotation axis direction.

[0008] According to the present invention, the status tack can be securely attached to the housing.

[0009] This is a plan view showing a resolver according to an embodiment of the present invention. This is a perspective view showing a resolver according to an embodiment. This is a perspective view showing the resolver according to an embodiment with the cover removed. This is an exploded perspective view of the resolver according to an embodiment. This is an enlarged perspective view of the stator of the resolver shown in Figure 4. This is a rear view of the resolver according to an embodiment. (A) is a cross-sectional view taken along line VII-VII in Figure 1, and (B) is an enlarged view of the portion indicated by arrow B in (A). (A) is a cross-sectional view taken along line VIII-VIII in Figure 6, and (B) is an enlarged view of the portion indicated by arrow B in (A). This is a perspective view of the housing in the embodiment viewed from the back side. (A) is an enlarged perspective view of the cover of the resolver shown in Figure 4, and (B) is an enlarged perspective view of the terminal block cover.

[0010] Figures 1 to 4 show a resolver (angle sensor) 1 according to an embodiment of the present invention. The resolver 1 is a VR (variable reluctance) type resolver. The resolver 1 has a rotor 10 and a stator 100 in a housing 200. The stator 100 is covered from the upper side in the axial direction by a cover 300.

[0011] The rotor 10 has a structure in which multiple thin rotor cores are stacked in the axial direction and is fixed to the output shaft of a rotating electric machine such as a motor (each not shown). The rotor 10 has a circular opening 10a, a non-circular outer circumference, and a keyway 11 that engages with a key fixed to the outer circumference of the output shaft.

[0012] In the following explanation, the direction of the output shaft of the rotor 10 will be referred to as the "axial direction," the direction perpendicular to the axial direction will be referred to as the "radial direction," and the direction of rotation around the output shaft will be referred to as the "circumferential direction." Furthermore, the terms "front" and "rear" refer to the lower and upper sides of Figure 1, while the terms "up" and "down" refer to the left-right direction in Figure 4 and the up-down direction in Figure 6.

[0013] The thin rotor cores that make up the rotor 10 are manufactured by press-forming sheets of electrical steel into a non-circular shape. Multiple rotor cores are stacked in the axial direction and crimped together to form the rotor 10.

[0014] The stator 100 is positioned outside the rotor 10 and mounted inside the housing (not shown) of the rotating electric machine. A predetermined gap is provided between the rotor 10 and the stator 100, allowing the rotor 10 to rotate inside the stator 100.

[0015] The stator 100 includes a stator tack 110. As shown in Figure 5, the stator tack 110 has a structure in which multiple thin plate-shaped stator cores are stacked in the axial direction. The stator tack 110 includes an annular core back 111 and multiple teeth 112 that protrude radially inward from the core back 111.

[0016] The stator core is formed by press-forming a sheet made of electromagnetic steel. Multiple of these stator cores are stacked in the axial direction and crimped together to obtain the stator tack 110.

[0017] Insulators 150, acting as insulating members, are fixed to the status tack 110 from the axial top and bottom. The insulators 150 are made of resin with insulating properties and are injection molded using the status tack 110 as an insert material. Note that the insulators 150 are not limited to being insert-molded together with the status tack 110; they can also be molded separately, and the insulators 150, divided axially, can be fixed to the status tack 110.

[0018] As shown in Figure 5, the insulator 150 has a portion (hereinafter referred to as the winding portion) 151 around which the conductor is wound. The winding portion 151 is formed to surround the entire circumference of the teeth 112 and comprises a cylinder 152 in the radial center, a flange 153 that extends axially up and down and circumferentially on the radially inner side of the cylinder 152, and a projection 154 that protrudes axially up and down on the radially outer side of the cylinder 152. The projection 154, together with the flange 153, restricts the radial direction of the cylinder 152 and prevents the winding from becoming unraveled when the conductor is wound around the cylinder 152. Then, the conductor is wound around the cylinder 152, whose radial direction is restricted by the flange 153 and the projection 154, to form a coil 157 (see Figure 7).

[0019] A terminal block 180 is integrally formed at the rear end of the insulator 150. The terminal block 180 has a rectangular shape in plan view and protrudes radially outward. Multiple terminals 190 (six in this example) are embedded in the terminal block 180, arranged with predetermined gaps in the circumferential direction.

[0020] The terminal 190 is integrally formed with the terminal block 180 by insert molding. The terminal 190 is made by bending a rectangular pin to form a roughly L-shape, and one end 191 of it protrudes from the top surface 181 of the terminal block 180. The lead wire (not shown) drawn out from the coil 157 is wrapped around the terminal 190 and there it is integrated with the one end 191 by TIG welding.

[0021] The other end 192 of the terminal 190 protrudes from the radially facing surface (hereinafter referred to as the rear end surface) 182 of the terminal block 180 and has a bent portion 192a that bends upward in the axial direction. The bent portion 192a of the other end 192 has an inclined portion that slopes outward in the radial direction. Reference numeral 183 in the figure indicates a through hole, which is formed in the mold after the pins that hold the terminal 190 are removed when the insulator 150 is injection molded using the terminal 190 as an insert material. The stator 100, having the above configuration, is mounted in the housing 200.

[0022] The housing 200 has a roughly rectangular shape in plan view, and flanges 210 projecting in the circumferential direction are formed on both sides of its rear end. Through holes 211 are formed in the flanges 210, and metal collars 212 are fixed to the through holes 211. The collars 212 are insert-molded with the housing 200. Through holes 211 are also formed at both corners of the front end of the housing 200, and collars 212 are fixed to these through holes 211.

[0023] A circular opening 220 that opens in the axial direction is formed approximately in the center of the housing 200. An annular peripheral wall 221 is formed in the opening 220, and a roughly bowl-shaped bottom wall 223 with a narrower inner diameter is formed on the axial lower side of the peripheral wall 221, and a step 222 having a surface facing in the axial direction is formed at the boundary between the bottom wall 223 and the peripheral wall 221.

[0024] The axial upper end of the peripheral wall 221 is provided with a base 230, which is a wall that is one step higher than the upper surface of the housing 200 in the axial direction. The base 230 is provided with a plurality of flanges 231 that face each other in the radial direction and project radially outward, and metal nuts 232 are fixed to the flanges 231 as fixing members.

[0025] Specifically, the flange 231 has a recess 231a that extends in the axial direction, and a nut 232 is housed in the recess 231a. The nut 232 is insert-molded into the housing 200, but is not limited to this method; the nut 232 can be fixed to the recess 231a by means of adhesive or press-fitting, and an adhesive or the like may be interposed.

[0026] A notch 233 is formed at the rear end of the base 230 (see Figure 4). With the stator 100 mounted on the housing 200, the terminal block 180 of the stator 100 is housed and positioned within the notch 233 with the terminal block cover 400 (described later) attached. The space formed by the notch 233 and the space formed by the opening 220 are in communication with each other.

[0027] A connector housing 240 is integrally formed with the housing 200. The connector housing 240 protrudes radially outward from the lower rear end of the housing 200. A connector pin 241 is insert-molded into the connector housing 240. As shown in Figure 8, the connector pin 241 is substantially L-shaped in side view, with one end 241a protruding and exposed to the inside of the connector housing 240, and the other end 241b protruding and exposed to the axially upper surface of the housing 200. The other end 241b elastically contacts and electrically connects with the bent portion 192a of the other end 192 of the terminal 190.

[0028] Figure 10(A) shows the cover 300. The cover 300 protects the coil 157, which is formed by winding a conductor, and is made of a metal or resin with magnetic properties that has a magnetic function. In the axial direction, the cover 300 faces the conductor and covers it. The cover 300 comprises an annular plate (hereinafter referred to as the top plate) 310 having a circular opening 311, a plate (hereinafter referred to as the side plate) 320 having a surface that extends axially from the edge of the top plate 310, and a flange 330 that extends radially outward from the edge of the side plate 320. Notches 340 are formed at the rear ends of the side plate 320 and the flange 330. The flange 330 has a plurality of projections 332 that project radially outward and are formed facing each other in the radial direction, and through holes 331 that penetrate axially are formed at the positions of the projections 332.

[0029] Figure 10(B) shows a terminal block cover 400. The terminal block cover 400 comprises a pair of vertical plates 410 and a horizontal plate 420 installed between the vertical plates 410. The vertical plates 410 comprise a rear plate 411 and a front plate 412 projecting axially from the rear plate 411. A radially extending notch 413 is formed in the axial middle portion of the front plate 412. An arm 414 projecting radially inward is formed on the axially lower side of the notch 413. A claw 414a is formed at the tip of the arm 414, projecting toward the opposing arm 414.

[0030] On the other hand, as shown in Figure 5, recesses 185 that are recessed in the circumferential direction are formed on both sides 184 of the terminal block 180, and protrusions 186 that project in the circumferential direction are formed in the recesses 185. The protrusions 186 have inclined surfaces 186a which increase in distance from the recesses 185 as they move radially inward.

[0031] Then, when the terminal block cover 400 is moved to cover the terminal block 180 from the radially outward direction, the claw 414a of the arm 414 elastically deforms along the inclined surface 186a away from the recess 185, and when it passes the protrusion 186, the claw 414a elastically returns to the recess 185 side and engages with the protrusion 186. In this way, the terminal block cover 400 is fixed to the terminal block 180.

[0032] The horizontal plate 420 comprises a first horizontal plate 421 and a second horizontal plate 422 installed between the rear plates 411, and a third horizontal plate 423 and a fourth horizontal plate 424 installed between the front plates 412. As shown in Figure 8(B), the first horizontal plate 421 and the second horizontal plate 422 cover one end 191 of the terminal 190 to which the lead wire is fixed, and the third horizontal plate 423 and the fourth horizontal plate 424 cover the bent portion 192a of the terminal 190 and the other end 241b of the connector pin 241 that are in contact with each other.

[0033] The stator 100 is inserted into the opening 220 of the housing 200 from the axial upper side, and the terminal block cover 400 is housed in the notch 233 of the base 230. As shown in Figure 7(B), the status tack 110 is placed on the axially facing surface of the step 222 positioned in the opening 220 of the housing 200, and in the axial direction, the top surface 113 of the status tack 110 is located on the cover 300 side of the top surface 230a of the base 230. The outer circumferential surface of the status tack 110 is in contact with the inner circumferential surface of the peripheral wall 221 of the housing 200. The flange 330 of the cover 300 is in contact with the top surface 113 of the status tack 110, and a gap L is formed between the flange 330 and the top surface 230a of the base 230.

[0034] As shown in Figure 3, the upper surface of the housing 200 has multiple (three in this example) projections 250 that protrude axially and form an arc shape in plan view. When attaching the cover 300 to the housing 200, the outer surface of its flange 330 is brought into contact with the inner surface of the projections 250, so that the centers of the cover 300 and the base 230 coincide. Then, the notch 340 of the cover 300 is aligned with the terminal block cover 400, and the through hole 331 is aligned with the nut 232 of the base 230.

[0035] In this state, the flange 330 of the cover 300 is in contact with the top surface 113 of the stator tack 110, and a gap L is created between the flange 330 and the top surface 230a of the base 230. The cover 300 is then attached to the housing 200 by tightening the bolt 350, which is a fixing member inserted through the through hole 331, onto the nut 232, which is a fixed member. At the same time, the stator tack 110 is pressed against the step 222 by the cover 300, and the stator 100 is attached to the housing 200. In other words, the stator tack 110 is fixed by being sandwiched between the cover 300 and the step 222 (in other words, the housing 200).

[0036] As shown in Figure 4, a groove 260 is formed on the upper surface of the housing 200 so as to surround the opening 220 and the other end 241b of the connector pin 241. An O-ring 261 is fitted into the groove 260 and protrudes axially upward from the groove 260. The O-ring 261 is made of rubber or resin and has protrusions 262 formed on its inner and outer circumferential surfaces. The protrusions 262 elastically support the O-ring 261 within the groove 260, preventing it from shifting position.

[0037] When attaching resolver 1 to the housing of the rotating electric machine, a bolt is inserted through the through hole 211 of the housing 200 and screwed into the threaded hole provided in the housing. At this time, the O-ring 261 is in close contact with the housing, preventing leakage of cooling oil used in the rotating electric machine and preventing foreign matter from entering the rotating electric machine.

[0038] In the figure, reference numeral 270 denotes a projection, and the resolver 1 is positioned by fitting the projection 270 into a recess provided in the housing of the rotating electric machine. The resolver 1 is attached to the rotating electric machine by passing a bolt through a collar 212 fixed to the housing 200 and tightening it into a female thread provided in the housing of the rotating electric machine. The projection 270 has a polygonal shape and can function as a rotation stopper for the resolver 1 relative to the housing of the rotating electric machine. The projection 270 is provided on the axially facing surface of the housing 200 and, as shown in Figure 8, protrudes above the stator 100 in the axial direction. Furthermore, since the projection 270 is provided radially outside the O-ring 261, the O-ring 261 can be constructed without being unnecessarily large.

[0039] In the above embodiment, the housing 200 is provided with a bowl-shaped bottom wall 223 at the opening 220. When the rotating electric machine uses cooling oil, the cooling oil can be stored in the bottom wall 223.

[0040] As shown in Figure 9, the housing 200 is provided with a plurality of ribs 224 that extend radially from the peripheral wall 221. This makes it possible to ensure strength without increasing the thickness of the housing 200.

[0041] In the resolver 1 with the above configuration, as shown in Figure 7(B), the lower end surface of the status tack 110 is in contact with the step 222 of the housing 200, the top surface 113 of the status tack 110 is in contact with the flange 330 of the cover 300, and the top surface 230a of the base 230 that forms the opening 220 is opposite the flange 330 in the axial direction with a gap L between them. Therefore, by moving the cover 300 toward the base 230 using appropriate fastening means, the status tack 110 is pressed against the step 222, and the status tack 110 can be firmly fixed to the housing 200. This allows the stator 100 to be attached to the housing 200.

[0042] In this embodiment, the clamping means is composed of a bolt 350 and a nut 232. When the bolt 350 is tightened against the nut 232 to press the flange 330, the status stack 110 is pressed against the step 222 by the flange 330, and the status stack 110 can be firmly fixed to the housing 200.

[0043] Also, instead of applying force to the status stack 110 from the outer peripheral side as in the case of press-fitting the status stack 110 into the housing 200, force is applied to the status stack 110 in the axial direction, so there is almost no deformation of the status stack 110. Thereby, it is possible to suppress a decrease in the angle detection accuracy of the resolver 1.

[0044] In particular, in the above embodiment, since the status stack 110 is attached to the housing 200 by utilizing the tightening force of the bolt 350 for attaching the cover 300 to the housing 200, no special member for attaching the status stack 110 is required, and the number of parts can be reduced.

[0045] The present invention is not limited to the above embodiment, and various modifications are possible as follows. i) The cover 300 is not limited to being made of a magnetic material, and any material can be used. For example, non-magnetic members, conductors, and non-conductive members can also be used.

[0046] ii) The configuration for attaching the cover 300 to the housing 200 is not limited to the bolt 350 and the nut 232, and the configuration is arbitrary. For example, a boss protruding in the axial direction may be formed on the housing 200, and the boss may be inserted into the through hole 331 of the cover 300 and thermally caulked. Also, when thermally caulking, the flange 330 of the cover 300 can be pressed by the head of the boss that is deformed to expand in the radial direction by heat.

[0047] iii) Alternatively, a pin having a head with a diameter larger than the shaft may be inserted into the recess 231a (see FIG. 7(B)) of the housing 200, and the recess 231a and the shaft may be adhered in a state where the flange 330 of the cover 300 is pressed by the head. In this case, the pin may be made of metal, and the pin may be heated by energization and welded to the recess 231a.

[0048] iv) Further, a protrusion protruding inward is formed on the inner peripheral surface of the recess 231a of the housing 200, and a pin having a shaft with a claw that can elastically move radially on the outer peripheral surface and a head larger in diameter than the shaft is inserted into the recess 231a, and a snap-fit structure can be adopted in which the claw is engaged with the protrusion. In this case, simultaneously with the snap fit, the flange 330 of the cover 300 is pressed by the head.

[0049] v) In the present invention, the cover 300 can be configured to be attached to the housing 200 without forming the recess 231a. For example, a groove extending in the circumferential direction is formed on the inner peripheral surface of the protrusion 250, and the flange 330 of the cover 300 is fitted into the groove so that the flange 330 presses the top surface 113 of the stator stack 110. In this case, the protrusion 250 may be configured to be elastically deformable radially outward, and the cover 300 may be pushed in from the upper side in the axial direction inside the protrusion 250.

[0050] vi) Alternatively, the flange 330 of the cover 300 can be adhered to the housing 200 in a state where the flange 330 presses the top surface 113 of the stator stack 110. For example, an adhesive can be applied to the gap L, and the adhesive can be cured while pressing the cover 300 toward the stator stack 110. In this case, the excess adhesive may be allowed to overflow from the gap L.

[0051] vii) As a configuration other than the above, the cover 300 can be attached to the housing 200 using appropriate clamping means. For example, it can be configured to press the flange 330 of the cover 300 with a clamp that sandwiches the housing 200 from above and below in the axial direction. <00​​​1…Resolver, 10…Rotor, 11…Keyway, 100…Stator, 110…Status tack, 111…Core back, 112…Teeth, 113…Top surface, 150…Insulator, 151…Winding section, 152…Cylinder, 153…Flange, 154…Projection, 157…Coil, 180…Terminal block, 181…Top surface, 182…Rear end surface, 183…Through hole, 184…Side surface, 185…Recess, 186…Convex, Inclined surface…186a, 190…Terminal, 191…One end, 192…Other end, 192a…Bent section, 200…Housing, 210…Flange, 211…Through hole, 212…Collar, 220…Opening, 221…Circumferential wall, 222…Step, 223…Bottom wall, 224…Rib, 230…Base (Wall), 230a...Top surface, 231...Flange, 231a...Recess, 232...Nut (fixed member), 233...Notch, 240...Connector housing, 241...Connector pin, 241a...One end, 241b...Other end, 250...Protrusion, 260...Groove, 261...O-ring, 262...Protrusion, Protrusion...270, 300...Cover, 310...Top plate, 311...Opening, 320...Side plate, 330...Flange, 331...Through hole, 332...Protrusion, 340...Notch, 400...Terminal block cover, 410...Vertical plate, 411...Rear plate, 412...Front plate, 413...Notch, 414...Arm, 414a...Claw, 420...Horizontal plate, 421...First horizontal plate, 422...Second horizontal plate, 423...Third horizontal plate, 424...Fourth horizontal plate, L...Gap.

Claims

1. An angle sensor comprising: a housing having an opening; a status tack housed in the opening; a rotor corresponding to the status tack; an insulating member covering the status tack; a conductor wound around the insulating member; and a cover covering the conductor, wherein, in the direction of the rotation axis of the rotor, one surface of the status tack is in contact with the housing, the other surface of the status tack is in contact with the cover, and the top surface of the wall forming the opening faces the cover with a gap in the direction of the rotation axis.

2. The angle sensor according to claim 1, wherein the top surface of the status tack is located on the cover side of the top surface of the wall in the direction of the rotation axis.

3. The angle sensor according to claim 1 or 2, wherein the housing has a recess that opens in the axial direction, a fixed member is fixed in the recess, and the cover is supported by being sandwiched between the fixed member and a fixing member corresponding to the fixed member.

4. The angle sensor according to claim 1 or 2, wherein the status tack is sandwiched and fixed between the cover and the housing.

Images