JP2012228024A - Resolver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resolver capable of reducing a manufacturing cost and assembly man-hours, shielding radio wave noise from a rotary electric machine and securing high detection accuracy.SOLUTION: The resolver comprises: a detection rotor 30 which is fixed to a rotary shaft 22b of a rotor 22 and rotated; a detection stator 32 which is housed and arranged inside a recess 19 of a case 18 attached to a housing 16 of a rotary electric machine 14, and has a detection coil wound around a salient pole projected at an inner peripheral part; and an anti-magnetic member 12 which is provided between the detection stator 32 and a stator 20 of the rotary electric machine 14, and shields magnetic fluxes or radio wave noise generated from the stator 20 or stator winding 26. The anti-magnetic member 12 includes a press-fitting part 40 which is press-fitted and fixed to the case 18, and a shield part 42 which is formed continuously to the press-fitting part 40 and shields between the detection stator 32 and the stator 20, and the detection stator 32 is pressurized and fixed in an axial direction by a press-fitting distal end face of the press-fitting part 40.

Description

  The present invention relates to a resolver, and more particularly to a resolver that is provided adjacent to a rotating electrical machine including a stator and a rotor and detects the rotational position of the rotor.

  2. Description of the Related Art Conventionally, a rotating electrical machine including a cylindrical stator fixed in a housing and a rotor that is rotatably supported inside the stator is known. A plurality of stator windings are wound around the inner periphery of the stator in a predetermined arrangement in the circumferential direction. By supplying driving power to these stator windings from the outside, a rotating magnetic field is formed inside the stator, and the rotor is driven to rotate by attraction and repulsion of the rotating magnetic field.

  In such a rotating electrical machine, in order to accurately control the rotational state of the rotor, the rotational position of the rotor is accurately detected, and the drive power is adjusted based on this. Therefore, for example, a variable reluctance resolver (hereinafter simply referred to as a resolver) may be provided adjacent to the rotating electrical machine as a rotational position sensor of the rotor.

  The resolver usually includes a detection rotor that is fixed to a rotor shaft of a rotating electrical machine and rotates together with the rotor, and a detection stator that is provided around the detection rotor. A plurality of salient poles are provided on the inner peripheral portion of the detection stator, and a detection coil is wound around the salient poles. Then, as the detection rotor rotates together with the rotor, the voltage induced in the detection coil due to the fluctuation of the gap permeance with the detection stator is taken out via the signal line to rotate the rotor. Detect position.

  The detection stator of the resolver is formed in a cylindrical shape in which magnetic steel plates made by punching in an annular shape are laminated in the axial direction. In that case, it is known that when the detection stator is assembled in a case fixed to the housing of the rotating electrical machine by press fitting or the like, distortion occurs due to radial stress acting in the detection stator, and detection accuracy deteriorates. .

  In addition, when the resolver is provided adjacent to the stator of the rotating electrical machine, the detection signal includes noise due to the influence of magnetic flux generated from the stator or the stator winding or radio wave noise. Detection signal may be affected.

  As a prior art document related to this, for example, Japanese Patent Application Laid-Open No. 2001-78373 (Patent Document 1) discloses a vehicle propulsion device that has an object to reduce the generation of noise in a signal of a rotational position detection mechanism. Is disclosed. In this propulsion device, it is described that a magnetic shielding member that shields magnetic flux and / or radio noise leaking from the generator motor is provided between the generator motor and the rotational position sensor. Further, it is described that a sensor stator of a rotational position detection mechanism and a magnetic shielding plate as a magnetic shielding member are fastened together with a mounting bolt and attached to a motor case.

  Japanese Patent Application Laid-Open No. 2002-95200 (Patent Document 2) discloses a non-magnetic material that shields magnetic flux and radio noise leaking from the generator motor between the motor stator of the generator motor and the sensor stator of the rotational position sensor. The magnetic-shielding structure of the motor assist device for vehicles which provided the magnetic-shielding part of this and the motor case integrally was described.

  Further, in Japanese Patent Application Laid-Open No. 2003-23761 (Patent Document 3), in a resolver fixing structure of a brushless motor, a resolver rotor is fixed to a rotating shaft of a brushless motor, and a resolver stator is fixed to a brushless motor case. It describes what is characterized in that it is pressed and supported by the case by a spring portion provided on the locking member press-fitted to the position.

JP 2001-78373 A JP 2002-95200 A JP 2003-23761 A

  When the magnetic shield member and the sensor stator are fastened together with mounting bolts and fixed to the case as described in Patent Document 1, the mounting portion or the fastening allowance including bolt insertion holes on the outer peripheral portions of the magnetic shield member and the sensor stator. It is necessary to secure a part. For this reason, there are problems that the outer shapes of the magnetic-shielding member and the sensor stator are both large and the manufacturing cost is high. In addition, since parts such as mounting bolts and fixing brackets are necessary, the number of parts increases and the number of assembling steps also increases.

  Further, as described in Patent Document 2, when the entire one end portion side of the motor stator is covered with the magnetic shield formed integrally with the motor case, the shape of the motor case itself is complicated and the manufacturing cost is high. In addition, the supply of cooling oil for cooling the motor stator may be hindered and sufficient cooling performance may not be obtained.

  Further, as described in Patent Document 3, in the configuration in which the resolver stator is pressed and supported on the case by the spring portion provided in the locking member that is press-fitted into the brushless motor case to a predetermined position, the spring of the locking member It is possible that the pressing force by the elastic member such as the part or rubber becomes weak with time and the fixing force of the resolver to the stator is reduced.

  An object of the present invention is to provide a resolver capable of reducing the manufacturing cost and the number of assembling steps, and shielding radio wave noise from a rotating electric machine to ensure high detection accuracy.

  A resolver according to the present invention is a resolver that is provided adjacent to a rotating electrical machine including a stator and a rotor and detects a rotational position of the rotor, and is fixed to a rotating shaft of the rotor and A detection rotor that rotates together with a rotor, and a salient pole that is provided around the detection rotor and is accommodated in a recess of a case that is attached to the housing of the rotating electrical machine, and that projects from an inner peripheral portion. A detection stator on which a detection coil is wound, a magnetic shielding member provided between the detection stator and the stator of the rotating electrical machine, and shielding magnetic flux or radio noise generated from the stator or the stator winding; The magnetic-shielding member includes a press-fit portion that is press-fitted and fixed to the case, and a shielding portion that is formed continuously from the press-fit portion and shields between the detection stator and the stator. And which is intended to fix the detection stator by a pressure tip surface by pressing the detection stator in the axial direction of the press-in portion into the recess of the case.

  In the resolver according to the present invention, the magnetic-shielding member includes a radial disk part having an opening at the center, and an annular part that is bent from an outer peripheral edge of the radial disk part and extends in the axial direction. The disc part may constitute the shielding part, and the annular part may constitute the press-fitting part.

  Further, in the resolver according to the present invention, the magnetic-shielding member further includes an inner peripheral part that is bent so as to extend from a central opening edge of the radial disk part toward the detection stator side, and the press-fitting part, the circular part The coil end portion protruding toward the one end side in the axial direction of the detection stator may be covered in a donut shape by the plate portion and the inner peripheral portion.

  According to the resolver according to the present invention, the detection stator of the resolver is pressed in the axial direction by the press-fitting tip surface of the press-fitting portion of the magnetic-shielding member press-fitted into the case, so that the detection stator is fixed in the case. As a result, it is possible to eliminate the deterioration of the detection accuracy due to the applied stress, and to firmly and stably fix the detection stator to the case with a predetermined pressing force. In addition, the shielding portion formed continuously with the press-fitting portion blocks the detection stator of the resolver and the stator of the rotating electrical machine, thereby improving the detection accuracy due to magnetic flux generated from the stator of the rotating electrical machine or radio noise. The effect can be prevented, and the number of parts, the number of assembly steps, and the manufacturing cost can be reduced.

It is an axial sectional view showing a resolver which is one embodiment of the present invention. It is a perspective view of a magnetic-shielding member. It is the elements on larger scale which show a mode that the detection stator of a resolver is pressed and fixed by the front end surface of the press-fit part of a magnetic-shielding member in FIG. It is a figure similar to FIG. 3 which shows the modification of a magnetic-shielding member.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the accompanying drawings. In this description, specific shapes, materials, numerical values, directions, and the like are examples for facilitating the understanding of the present invention, and can be appropriately changed according to the application, purpose, specification, and the like.

  FIG. 1 is an axial sectional view showing a resolver 10 according to this embodiment, FIG. 2 is a perspective view of a magnetic-shielding member 12 assembled to the resolver 10, and FIG. 3 is a detection stator of the resolver 10 by a press-fitting portion of the magnetic-shielding member 12. It is a figure which expands and shows a mode that is fixed in a case.

  As shown in FIG. 1, the resolver 10 is provided adjacent to the rotating electrical machine 14. The rotating electrical machine 14 is accommodated in a substantially bottomed cylindrical housing 16. The open end of the housing 16 is closed by a case 18 that houses the resolver 10.

  The rotating electrical machine 14 includes a stator 20 and a rotor 22. The stator 20 has a cylindrical shape formed by laminating magnetic steel plates in the axial direction, and a plurality of teeth 24 formed so as to protrude radially inward on the inner peripheral portion are provided in an even arrangement in the circumferential direction. A stator winding 26 is wound around the teeth 24.

  The rotor 22 includes a substantially cylindrical rotor core 22a, and a rotary shaft 22b fixed through the central hole of the rotor core 22a. The rotor core 22a is disposed inside the stator 20 with a gap therebetween. The rotating shaft 22b is rotated by the rotating shaft 22b of the rotating electrical machine 14 via a bearing 28 disposed at the center of the case 18 and a bearing (not illustrated) disposed at the center of the bottom of the housing 16 (not illustrated). Supported as possible.

  The resolver 10 includes a detection rotor 30 and a detection stator 32. The detection rotor 30 is configured, for example, by laminating magnetic steel plates punched into a substantially elliptical shape in the axial direction and integrally connecting them by caulking or the like. In the present embodiment, an example is shown in which the detection rotor 30 is configured by laminating seven magnetic steel plates.

  A rotation shaft 22 b of the rotor 22 of the rotating electrical machine 14 is inserted into the center hole of the detection rotor 30. Further, a key groove is formed at the edge of the center hole of the detection rotor 30, and a detection rotor for the rotation shaft 22b is fitted into the key groove by fitting a key 34 protruding from the rotation shaft 22b. Thirty circumferential positions are determined. Further, when the end portion (the left side in FIG. 1) of the rotation shaft 22b is inserted and assembled, the detection rotor 30 has its axial end surface brought into contact with the protruding contact portion 36 on the rotation shaft 22b. The position of the detection rotor 30 in the axial direction with respect to the rotating shaft 22b is determined.

  In the above description, the rotation position of the detection rotor 30 has been described as being determined by the fitting of the key and the key groove. However, the present invention is not limited to this, and the detection rotor is press-fitted into the end of the rotation shaft 22b. The rotational position and / or the axial position of the detection rotor relative to the rotary shaft may be fixed by interference fitting or the like.

  The detection stator 32 of the resolver 10 is provided around the detection rotor 30 via a gap. The detection stator 32 is configured, for example, by laminating magnetic steel plates punched into a substantially annular shape in the axial direction and integrally connecting them by caulking or the like. In the present embodiment, an example in which the detection rotor 30 is configured by stacking five magnetic steel plates is shown. That is, the detection stator 32 in this embodiment is formed so that its axial thickness is thinner than that of the detection rotor 30. However, the present invention is not limited to this, and the same thickness may be formed by the same number of magnetic steel plates, or the detection stator may be configured to be thicker.

  A plurality of teeth portions projecting radially inward are formed on the inner circumferential portion of the detection stator 32 in an even arrangement in the circumferential direction, and a detection coil 38 is wound around the teeth portions. . The detection coil 38 includes coil end portions 39 that protrude outward from both axial end surfaces of the detection stator 32 (see FIG. 3). Further, a signal line (not shown) is electrically connected to the detection coil 38, and the detection signal can be taken out through the signal line.

  The detection stator 32 of the resolver 10 configured as described above is accommodated and disposed in the recess 19 formed in the case 18. The detection stator 32 is pressed and fixed by a magnetic shielding member 12 (described later) press-fitted into the recess 19 of the case 18.

  As shown in FIGS. 1 to 3, the magnetic-shield member 12 includes an annular press-fit portion 40 and a shielding portion 42 formed continuously with the press-fit portion 40. The press-fit portion 40 of the magnetic-shield member 12 is bent from the outer peripheral edge of the shielding portion 42 and extends in the axial direction. The press-fit portion 40 has a function of fixing the magnetic-shielding member 12 to the case 18 by being press-fitted into the concave portion 19 formed in the case 18 from the rotating electrical machine 14 side, and an axial end surface of the detection stator 32 by the press-fit tip surface 44. The detection stator 32 is fixed in the case 18 by pressing the outer periphery of the case 18.

  The shielding part 42 of the magnetic shielding member 12 is formed by a radial disk part in which an opening 45 for inserting the rotary shaft 22b is formed in the center. Further, the width in the radial direction of the shielding part 42 is set such that the edge part of the opening 45 is substantially aligned with the inner peripheral position of the detection stator 32 when assembled to the case 18 together with the resolver 10.

  The magnetic shield member 12 is preferably formed of a nonmagnetic plate material such as aluminum, stainless steel, or copper. By configuring the magnetic shield member 12 with a non-magnetic plate material in this way, it is effective for magnetic flux or radio noise generated from the stator 20 or the stator winding 26 of the rotating electrical machine 14 to reach the detection stator 32 by air propagation. Can be shielded.

  Moreover, it is preferable that the press-fit part 40 and the shielding part 42 are integrally formed in the magnetic-shielding member 12 by press molding, for example. By integrally molding in this way, the above-described magnetic-shielding function and the pressing and fixing function of the detection stator 32 can be realized with one member, and the number of parts, the number of assembly steps, and the manufacturing cost can be reduced.

  However, the magnetic-shield member 12 is not necessarily limited to being integrally formed. For example, after the annular press-fit portion 40 and the disc-shaped shielding portion 42 are separately formed, welding or the like is performed. It may be integrated. In this case, there is an advantage that the thickness of the press-fit portion 40 and the thickness of the shielding portion 42 are easily made different. For example, the press-fit portion 40 is thickened to ensure press-fit strength and the width of the press-fit tip surface 44. On the other hand, the shielding part 42 may be thinned to reduce the weight and reduce the material cost.

  Referring to FIG. 3, the recess 19 formed in the case 18 includes a first recess 46, a second recess 48, and a third recess 50 in order from the side opposite to the rotating electrical machine 14 side.

  The first recess 46 is formed to have an axial width or depth d1 that is larger than the protruding width of the coil end portion 39 of the detection coil 38 protruding from the end face of the detection stator 32. Further, the inner diameter r <b> 1 of the first recess 46 is set larger than the radius of the coil end portion 39. This prevents the coil end portion 39 from contacting the case 18 when the detection stator 32 is fixed in the case 18.

  The second recess 48 is formed to have an axial width or depth d2 and is defined by an annular step 47 and a peripheral surface having an inner diameter r2 (that is, r2> r1) larger than the first recess 46. The axial width d2 of the second recess 48 is set to substantially correspond to the thickness of the laminated steel plate of the detection stator 32. Thus, when the detection stator 32 is accommodated in the second recess 48, the axial end surface of the detection stator 32 is substantially flush with the annular stepped portion 49 of the third recess 50 or slightly protrudes. It is. The inner diameter r <b> 2 of the second recess 48 is set to be substantially the same as that of the detection stator 32. Here, “substantially the same” means that the radial position of the detection stator 32 can be determined without rattling, and that the stress that affects the detection accuracy is not generated in the contained detection stator 32. This means that the contact pressure is set.

  The third recess 50 is formed to have an axial width or depth d3 and is defined by an annular step 49 and a peripheral surface having an inner diameter r3 (that is, r3> r2) larger than the second recess 48. The inner diameter r3 of the peripheral surface of the third recess 50 is set to a dimension that allows the press-fit portion 40 of the magnetic-shielding member 12 to be press-fit. In addition, the axial width d3 of the third recess 50 is set to such an extent that the press-fitted state of the press-fitted magnetic shield member 12 can be stably maintained. In the present embodiment, the axial width d3 of the third recess 50 is set to be smaller than the press-fit portion 40 of the magnetic-shielding member 12, whereby the press-fit tip surface 44 engages with the annular step portion 49 and the magnetic-shield member 12. When the press-fitting is completed, the shielding portion 42 of the magnetic shielding member 12 is in a state of extending in the radial direction at a position protruding from the end face of the case 18.

  However, the present invention is not limited to this, and the axial width d3 of the third recess 50 may be set to be substantially the same as or larger than that of the press-fit portion 40 of the magnetic shielding member 12. In this way, the shielding part 42 of the magnetic-shielding member 12 is substantially flush with the end surface of the case 18 or is in a recessed position, and the resolver 10 is moved closer to the rotating electrical machine 14 to obtain an axial dimension including the rotating electrical machine 14. The magnetic shielding member 12 does not become an obstacle when downsizing.

  When the detection stator 32 of the resolver 10 is accommodated and disposed in the recess 19 of the case 18 having such a size or size, first, the detection stator 32 is disposed on the rotating electrical machine 14 side (in the direction of arrow A in FIG. 3). The outer peripheral portion of the axial end surface of the detection stator 32 is disposed in contact with the annular step portion 47 of the second recess 48. Thereafter, the press-fit portion 40 of the magnetic shield member 12 is press-fitted into the third recess 50 to a position where the press-fit tip surface 44 abuts on the annular step portion 49. Thereby, the detection stator 32 of the resolver 10 is fixed in the case 18 in a state where the detection stator 32 is pressed with a predetermined pressing force by the press-fitting tip surface 44 of the press-fitting portion 40. In this way, the press-fitting depth or press-fitting position of the press-fitting part 40 is defined by the annular step part 49, so that the pressing force of the detection stator 32 by the press-fitting part 40 can be prevented from varying among the individual resolvers.

  Further, when the case 18 assembled with the magnetic shielding member 12 in this way is attached to the opening end portion of the housing 16 of the rotating electrical machine 14 by bolting or the like, as shown in FIG. It is provided between the detection stator 32 and the stator 20 and the stator winding 26 of the rotating electrical machine 14. More specifically, the magnetic shielding member 12 is disposed in a state where the detection stator 32 is shielded from the stator 20 of the rotating electrical machine 14 at a position closer to the detection stator 32.

  As described above, according to the resolver 10 of the present embodiment, the shielding portion 42 formed continuously with the press-fit portion 40 blocks the detection stator 32 of the resolver 10 and the stator 20 of the rotating electrical machine 14. In addition, the influence on the detection accuracy due to magnetic flux or radio noise generated from the stator 20 of the rotating electrical machine 14 can be prevented, and the number of parts, the number of assembly steps, and the manufacturing cost can be reduced.

  Further, in the resolver 10 of the present embodiment, the detection stator 32 of the resolver 10 is pressed in the axial direction by the press-fitting tip surface 44 of the press-fitting portion 40 of the magnetic-shielding member 12 press-fitted into the case 18 so that the detection stator 32 is brought into the case 18. Therefore, it is possible to eliminate the deterioration of detection accuracy due to the radial stress applied to the detection stator 32, and to fix the detection stator 32 to the case firmly and stably with a predetermined pressing force. it can.

  Furthermore, in the resolver 10 of this embodiment, since the detection stator 32 is fixed by the magnetic-shielding member 12 press-fitted into the case 18, the number of parts is larger than when fixing to the case using mounting bolts or fixing brackets. And assembly man-hours can be reduced.

  Furthermore, in the resolver 10 of this embodiment, the shielding part 42 of the magnetic-shield member 12 is disposed between the detection stator 32 and the stator 20 and close to the detection stator 32, and the size of the shield part 42 is also the detection stator 32. Is roughly equivalent to Therefore, the presence of the magnetic shielding member 12 does not hinder the cooling of the stator 20 and the stator winding 26 of the rotating electrical machine 14 by the cooling oil.

  In the above-described embodiment, the annular stepped portion 49 is provided between the second recessed portion 48 and the third recessed portion 50 in the case 18 so as to regulate the press-fitting depth of the magnetic shielding member 12. Instead, the third recess may be eliminated and the inner surface of the second recess may be extended to the case end surface. Then, the detection stator 32 can be pressed in the axial direction over the entire press-fitting tip surface 44 of the press-fitting portion 40 and firmly fixed. In this case, if the pressure input and the press-fitting depth of the magnetic-shielding member are controlled using an instrument or device such as a press-fitting jig, the pressing force against the detection stator does not vary.

  Next, with reference to FIG. 4, the resolver which is a modification of the said embodiment is demonstrated. In the resolver 10 of this modification, the magnetic-shielding member 12 further has an inner peripheral portion that is bent so as to extend from the edge of the central opening 45 of the radial disk portion 42 toward the detection stator side. Thereby, the magnetic-shielding member 12 has covered the coil end part 39 which protrudes in the axial direction one end side of the detection stator 32 by the press-fit part 40, the disc part 42, and the inner peripheral part 43 in donut shape. Since the other configuration is the same as that of the above embodiment, the same reference numerals are assigned to the same components, and redundant description is omitted.

  According to the resolver 10 of the modified example, it is possible to achieve the same effects as the above embodiment. In addition, since the coil end portion 39 facing the rotating electrical machine 14 side is covered as described above, the cooling oil circulated and supplied to the rotating electrical machine 14 to cool the stator 20 and the stator winding 26. Can be prevented from being applied to the coil end portion 39 of the detection coil 38 of the resolver 10. As a result, it is possible to suppress the deterioration of the insulation performance of the coil conductor and the damage to the insulating film caused by foreign matters such as metal powder contained in the cooling oil adhering to or colliding with the coil end portion 39.

  Note that the resolver 10 that is a rotational position sensor does not need to be cooled by cooling oil unlike the rotating electrical machine 14 that is actively driven to rotate and is likely to reach a high temperature, so that the coil end portion is covered and cooled as described above. There is no problem even if oil is not applied.

  DESCRIPTION OF SYMBOLS 10 Resolver, 12 Magnetic-shield member, 14 Rotating electric machine, 16 Housing, 18 Case, 19 Recessed part, 20 Stator, 22 Rotor, 22a Rotor core, 22b Rotating shaft, 24 teeth, 26 Stator winding, 28 Bearing, 30 Detection rotor, 32 Detection stator, 34 Key, 36 Contact part, 38 Detection coil, 39 Coil end part, 40 Press-in part, 42 Shield part or radial disk part, 43 Inner peripheral part, 44 Press-in front end face, 45 Opening, 46 1st recessed part, 47, 49 Annular step part, 48 2nd recessed part, 50 3rd recessed part, d1, d2, d3 Axial width, r1, r2, r3 inner diameter.

Claims (3)

A resolver that is provided adjacent to a rotating electrical machine including a stator and a rotor, and detects a rotational position of the rotor,
A detection rotor fixed to a rotating shaft of the rotor and rotating together with the rotor;
A detection stator provided around the detection rotor and housed in a concave portion of a case attached to the housing of the rotating electrical machine, and a detection coil is wound around a salient pole projecting from an inner peripheral portion When,
A magnetic shielding member that is provided between the detection stator and the stator of the rotating electrical machine and shields magnetic flux generated from the stator or the stator winding or radio wave noise;
The magnetic shield member has a press-fit portion that is press-fitted and fixed to the case, and a shielding portion that is formed continuously with the press-fit portion and shields between the detection stator and the stator, Pressing the detection stator in the axial direction at the press-fitting tip surface of the press-fitting portion to fix the detection stator in the recess of the case;
Resolver. The resolver according to claim 1, wherein
The magnetic-shielding member has a radial disk portion whose center is open, and an annular portion that is bent from an outer peripheral edge of the radial disk portion and extends in the axial direction, and the radial disk portion is the shielding portion. The resolver is characterized in that the annular portion constitutes the press-fit portion. The resolver according to claim 2, wherein
The magnetic-shielding member further includes an inner peripheral portion that is bent so as to extend from a central opening edge of the radial disk portion toward the detection stator, and is formed by the press-fit portion, the disk portion, and the inner peripheral portion. A resolver characterized in that a coil end portion projecting toward one axial end of the detection stator is covered in a donut shape.

Images