JP2011217519A - Electromagnetic shielding structure of resolver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic shielding structure of a resolver improving the detection accuracy of the resolver by enhancing the shielding property of electromagnetic noises generated from the coil end of a motor.SOLUTION: The electromagnetic shielding structure of the resolver 30 detects the angle of rotation of the motor 2. The electromagnetic shielding structure of the resolver 30 includes a resolver stator 34 including a resolver stator core 32 configured by superposing a plurality of electromagnetic steel plates and a resolver stator coil 33 wound around the resolver stator core 32 and a shielding plate 35 disposed between the motor 2 and the resolver stator core 32 for shielding the electromagnetic noises generated from the motor 2. In the electromagnetic shielding structure of the resolver 30, the shielding plate 35 includes a shielder 35a disposed between the resolver stator core 32 and the shielding plate 35 through an air gap G and a leg 35b integrally formed with the shielder 35a while being supported on the resolver stator 34 side.

Description

  The present invention relates to an electromagnetic shielding structure for a resolver that detects the number of rotations (rotation angle) of a rotor shaft of a motor, and more particularly to an electromagnetic shielding structure for a resolver that shields electromagnetic noise generated from a coil end of a stator of a motor. .

  For example, a resolver is generally used as a sensor for detecting the rotational speed of a motor or generator (hereinafter simply referred to as “motor”) for driving or power generation mounted on a vehicle such as an electric vehicle or a hybrid vehicle. . Due to space limitations, the resolver may be placed inside (inner circumference) the coil end of the stator of the motor. In this case, the resolver detection accuracy is reduced by electromagnetic noise generated at the coil end. May decrease.

  In order to prevent such a problem, for example, in the invention according to Patent Document 1, a shield member (electromagnetic shield) is provided between the coil end and the resolver.

  In the resolver of the invention of this Patent Document 1, a shield member as a shield ring is attached to the outer peripheral side of the back yoke of the stator core (the outer peripheral side of the stator core) by an adhesive or welding. The shield member is made of a magnetic material (electromagnetic steel plate). According to the present invention, “the magnetic field generated from the coil end of the motor collects the magnetic flux in the shield member, so that the magnetic field has less influence on the teeth of the stator core as the main body. As a result, the angle signal generated by the resolver is accurate. It is possible to suppress a decrease in torque and motor vibration in motor control. "

International Publication No. 2006/080567 Pamphlet

  However, in the invention of Patent Document 1, as described above, the shield member is fixed to the outer peripheral side of the stator core of the resolver by an adhesive or welding, and the shield member is not magnetically insulated from the stator core. The electromagnetic noise shielded by is transmitted to the stator core, noise enters the output signal of the resolver, and the detection accuracy of the resolver decreases.

  Accordingly, an object of the present invention is to provide an electromagnetic shielding structure for a resolver that improves the detection accuracy of the resolver by providing a gap between the shielding portion that shields electromagnetic noise and the stator core of the resolver.

The present invention according to claim 1 (see, for example, FIG. 4) is an electromagnetic shielding structure of a resolver (30) for detecting a rotation angle of a motor (2).
A resolver stator (34) having a resolver stator core (32) configured by stacking a plurality of electromagnetic steel plates, and a resolver stator coil (33) wound around the resolver stator core (32);
A shielding plate (35) disposed between the motor (2) and the resolver stator core (32) for shielding electromagnetic noise generated from the motor (2),
The shielding plate (35) is formed integrally with the shielding portion (35a) disposed between the resolver stator core (32) via a gap (G) and the shielding portion (35a). A leg portion (35b) supported on the resolver stator (34) side,
The electromagnetic shielding structure of the resolver (30) is characterized by the above.

In the invention according to claim 2 (see, for example, FIG. 4), the gap (G) is large enough to ensure magnetic insulation between the shielding plate (35) and the resolver stator core (32). Set,
It exists in the electromagnetic shielding structure of the resolver (30) of Claim 1 characterized by the above-mentioned.

In the invention according to claim 3 (see, for example, FIG. 4), the shielding plate (35) is in a state where the shielding portion (35 a) holds the gap (G) between it and the resolver stator core (32). In addition to the resolver stator (34), the synthetic resin annular holding part (36) is integrally formed through the leg part (35b).
It exists in the electromagnetic shielding structure of the resolver (30) of Claim 1 or 2 characterized by the above-mentioned.

In the invention according to claim 4 (see, for example, FIG. 4), the resolver stator core (32) is directly positioned on the motor case (22) made of a non-magnetic material, and the resolver stator (34) Attached to the motor case (22) via the part (36),
The shielding plate (35) is made of a magnetic material.
It exists in the electromagnetic shielding structure of the resolver (30) of Claim 3 characterized by the above-mentioned.

In the invention according to claim 5 (see, for example, FIG. 4), the resolver (30) is disposed on the inner diameter side of the coil end (5) of the motor (2),
The shielding portion (35a) of the shielding plate (35) is disposed so as to cover the outer peripheral surface (32c) of the resolver stator core (32).
It exists in the electromagnetic shielding structure of the resolver (30) of Claim 3 or 4 characterized by the above-mentioned.

  In addition, although the code | symbol in the said parenthesis is for contrast with drawing, this is for convenience for making an understanding of invention easy, and has no influence on the structure of a claim. It is not a thing.

  According to the invention according to claim 1, by providing a predetermined gap between the shielding portion and the resolver stator core, the shielding portion is attached to the resolver stator core by, for example, an adhesive or welding, It is possible to make it difficult for electromagnetic noise generated from the motor to enter the resolver stator core, and it is possible to prevent a decrease in the detection accuracy of the resolver due to electromagnetic noise.

  According to the invention of claim 2, since the gap between the shielding plate and the resolver stator core is sized so as to ensure magnetic insulation, electromagnetic noise is transmitted from the shielding plate to the resolver stator core. Since it can suppress, the detection accuracy of a resolver can be improved.

  According to the invention of claim 3, since the shielding plate can be formed integrally with the resolver stator by the synthetic resin holding portion without being attached by an adhesive or welding, it is easy to manufacture and can be synthesized. Because the resin-made holding portion can achieve magnetic insulation between the shielding plate and the resolver stator core, the detection accuracy of the resolver can be improved.

  According to the invention of claim 4, since the resolver stator is directly positioned on the motor case, the positioning accuracy of the resolver stator is improved, and the motor case that is in direct contact with the resolver stator is formed of a nonmagnetic material. In addition, electromagnetic noise generated from the motor is not easily transmitted to the resolver stator via the motor case. Furthermore, by forming the shielding plate with a magnetic material, it is possible to further make it difficult for electromagnetic noise to enter the resolver stator core, and to prevent a decrease in resolver detection accuracy due to electromagnetic noise. Moreover, since it is attached to the case via the synthetic resin holding portion, it is not necessary to provide a dedicated attachment portion for attaching the resolver stator to the case, and the configuration can be simplified correspondingly. .

  According to the invention of claim 5, the shielding portion of the shielding plate is disposed so as to cover the inner diameter side of the coil end of the motor and the outer peripheral surface of the resolver stator core. Electromagnetic noise generated at the coil end and directed to the resolver stator core can be effectively shielded.

The skeleton figure which shows a part of drive part of the electric vehicle which can apply this invention, and a hybrid vehicle. The longitudinal cross-sectional view which shows schematic structure of the resolver vicinity. 3A is a longitudinal sectional view of the resolver, and FIG. 3B is a right side view of the resolver. FIG. 3 is an enlarged longitudinal sectional view showing a detailed configuration near a resolver.

<First Embodiment>
A first embodiment according to the present invention will be described below with reference to FIGS.

  FIG. 1 is a skeleton diagram showing a part of a drive unit 1 of a vehicle such as an electric vehicle or a hybrid vehicle to which the electromagnetic shielding structure of a resolver according to the present invention can be applied.

  In the drive unit 1 shown in the figure, a motor 2 is provided as a drive source. The motor 2 includes a stator 3 that is fixed to a case (not shown), and a rotor 4 that is rotatably disposed on the inner diameter side of the stator 3. A coil is wound around the stator 3, and a coil end 5 is formed at a portion of the coil that protrudes from the axial direction of the stator 3 (left-right direction in the figure). A rotor shaft (motor shaft) 6 serving as an output shaft extends from the center of the rotor 4, and a drive gear 7 is fixed to the rotor shaft 6.

  A driven gear 8 is meshed with the drive gear 7, and the driven gear 8 is fixed to one end portion of the counter shaft 9, and a differential drive pinion gear 10 is fixed to the other end portion of the counter shaft 9. . A differential ring 11 is meshed with the differential drive pinion gear 10. The differential ring gear 11 constitutes a part of the differential device 12, and an output shaft 13 extends from the differential device 12 and is connected to a wheel (not shown).

  In the drive unit 1 described above, when the rotor 4 of the motor 2 rotates, the rotation of the rotor shaft 6 integrated with the rotor 4 causes the drive gear 7, the driven gear 8, the counter shaft 9, the differential drive pinion gear 10, the differential ring gear 11, the differential. It is transmitted to the wheel via the device 12 and the output shaft 13. Thus, since the rotation of the rotor shaft 6 is directly transmitted to the wheels via the respective shafts and gears, the rotational speed of the rotor shaft 6 is set with high accuracy in order to control the rotational speed and torque of the wheels. Therefore, it is necessary to detect the rotational speed of the rotor shaft 6 with high accuracy.

  A resolver 30 according to the present embodiment that detects the rotation of the rotor shaft 6 with high accuracy is disposed in the vicinity of the base end portion of the rotor shaft 6 and at a position corresponding to the coil end 5 of the stator 3. Yes. A specific configuration in the vicinity of this is shown in FIG.

  FIG. 2 is a longitudinal cross-sectional view of the resolver 30 and the configuration in the vicinity thereof, taken along a plane including the axis C of the rotor shaft 6. A schematic configuration in the vicinity of the resolver 30 will be described with reference to FIG. Details of the resolver 30 will be described later with reference to FIGS.

  As shown in FIG. 2, the rotor shaft 6 of the motor 2 passes through the rotor 4 along the axis C. The rotor shaft 6 is rotatably supported by a bearing 20 at one end 6a (left end in the figure). The other end portion (right end portion in the figure) of the rotor shaft 6 has approximately three steps with different outer diameters, that is, a small diameter portion 6b, a medium diameter portion 6c, and a large diameter portion 6d in order from the end. The small-diameter portion 6b is fitted with the drive gear 7 described above, and the medium-diameter portion 6c is fitted with a bearing 21 that rotatably supports the other end of the rotor shaft 6, and the large-diameter portion 6d. A resolver 30, which will be described later in detail, is disposed.

  The stator 3, the bearings 20 and 21, and the resolver 30 of the motor 2 described above are directly supported by a metal (for example, aluminum) case (motor case) 22. The stator 3 has an outer peripheral surface fitted to a cylindrical inner peripheral surface 22a formed on the case 22, the bearing 20 is fitted to a step portion 22c formed on the wall portion 22b, and the bearing 21 is The resolver 30 is fitted to the inner peripheral surface 22f of the flange portion 22e extending inward from another wall portion 22d, and the resolver 30 is a cylindrical tubular wall extending along the axis C from the inner end of the wall portion 22d. The inner peripheral surface 22h of 22g is fitted.

  As described above, the motor 2 is positioned by fitting the stator 3 directly to the case 22, and the rotor shaft 6 integrated with the rotor 4 is fixed to the both ends by the bearings 20, 21 fitted directly to the case 22. Since it is supported and positioned, the rotor shaft 6 and the rotor 4 can be rotated with high rotational accuracy. Similarly, the resolver 30 is positioned by a cylindrical wall 22g that is a part of the case 22 and a holding portion 36 that is integral with the resolver stator 34. On the other hand, the resolver rotor 31 that will be described in detail later is provided on the rotor shaft 6 described above. Therefore, the resolver rotor 31 can be rotated with high accuracy with respect to the resolver stator 34. Therefore, as will be described later, it is possible to ensure high detection accuracy of the resolver 30 by shielding electromagnetic noise.

  The configuration of the resolver 30 will be described in detail with reference to FIGS. 3 (A) and 3 (B). Here, FIG. 3A is a front longitudinal sectional view of the resolver 30 taken along a plane including the axis C, and FIG. 3B is a right side view of the resolver 30. As shown in these drawings, the resolver 30 includes an annular resolver rotor 31, a resolver stator core 32 and a resolver stator coil 33, a resolver stator 34, a shielding plate 35, an annular holding portion 36, and the like. Yes.

  As shown in FIG. 3B, the resolver rotor 31 has an inner periphery 31a formed in a circular shape and an outer periphery 31b formed in a shape in which four corners of a square are rounded. The part is provided with a rotation stopper 31c. As shown in FIG. 2, the rotation stopper 31 c is formed on the outer peripheral surface of the rotor shaft 6 along the axis C when the resolver rotor 31 is fitted to the large diameter portion 6 d of the rotor shaft 6. By engaging with a groove (not shown), the relative rotation of the resolver rotor 31 with respect to the rotor shaft 6 is prevented. As shown in the figure, the resolver rotor 31 is positioned by fitting the large diameter portion 6d with a retaining member 23 after being fitted to the large diameter portion 6d, and in the axial center C direction. Movement is prohibited.

  The resolver stator core 32 is configured by stacking a plurality of identical magnetic steel plates in the direction of the axis C, and is protruded inward to each of positions where the annular annular portion 32a and the inner peripheral surface thereof are equally divided. The resolver stator coil 33 is wound around the tooth portion 32b. A resolver stator 34 is configured by the resolver stator core 32 and the resolver stator coil 33. The operation of the resolver 30 by the resolver rotor 31 and the resolver stator 34 is the same as that of a generally known resolver, and thus the description thereof is omitted.

  The shielding plate 35 is integrally formed with a tubular shielding portion 35a and a flange-like leg portion 35b provided with one end portion along the direction of the axis C of the shielding portion 35a. The shielding plate 35 can be formed, for example, by forming a general steel plate into a tubular shape and bending one end portion inward. In the shielding plate 35, the leg portion 35 b is held by a holding portion 36 described below, so that the shielding portion 35 a ensures a gap G between the outer peripheral surface 32 c of the resolver stator core 32. This point will be described in detail later with reference to FIG.

  The holding portion 36 is the same as an annular main body 36a and a cylindrical lead wire outlet 36b extending along the axis C from one end surface (the right end surface in FIG. 3A) of the main body 36a. It has three pedestals 36c projecting at respective positions that divide the end face into three equal parts in the circumferential direction. The main body 36a includes therein the resolver stator 34 and the inner diameter side of the leg portion 35b of the shielding plate 35. The lead wire outlet 36b is configured so that the end of the resolver stator coil 33 is connected to the main body 36a. Is used as a lead wire L. The three female bases 36d are embedded in the three bases 36c. As shown in FIG. 2, the resolver 30 is fixed to the case 22 via the holding portion 36 by screwing bolts 24 penetrating a part of the case 22 into the three female screw portions 33d. Yes. The holding portion 36 includes the above-described main body 36a, lead wire outlet 36b, and three pedestals 36c integrally formed of synthetic resin, and is integrally formed with the above-described resolver stator 34 and shielding plate 35. . For example, when the holding unit 36 is molded using a mold, the above-described resolver stator 34 and the shielding plate 35 are disposed in a cavity into which a synthetic resin in a molten state is poured. Can be molded integrally.

  FIG. 4 is a detailed view of the vicinity of the resolver 30 in FIG. With reference to the figure, the positional relationship etc. with respect to the other member of the shielding board 35 are explained in full detail.

  As shown in the figure, most of the resolver 30 except the part of the holding portion 36 is disposed on the inner diameter side of the coil end 5. For this reason, the resolver stator core 32 is susceptible to electromagnetic noise generated from the coil end 5, in particular, electromagnetic noise generated from a coil wound in the radial direction at the coil end 5. Therefore, in the present embodiment, the electromagnetic noise is shielded by arranging the shielding plate 35 between the coil end 5 and the resolver stator core 32. Further, by separating the shielding portion 35a of the shielding plate 35 without contacting the outer peripheral surface 32c of the resolver stator core 32, that is, a gap sufficient to ensure magnetic insulation between the shielding plate 35a and the resolver stator core 32. By ensuring G (for example, 2 to 3 mm), electromagnetic noise is more difficult to enter the resolver stator core 32.

  Here, in the present embodiment, the tip 22i side of the cylindrical wall 22g, which is a part of the case 22 to which the holding portion 36 is fitted, enters the inner diameter side of the shielding portion 35a of the shielding plate 35, and The tip 22 i is in contact (contact) with the outer peripheral surface 32 c of the resolver stator core 32. Thereby, when positioning the resolver 30 with respect to the case 22, positioning accuracy is higher than when only the outer peripheral surface of the holding portion 36 made of synthetic resin is fitted to the inner peripheral surface 22h of the cylindrical wall 22g. It can be further increased. That is, by fitting the outer peripheral surface 32c of the magnetic steel plate resolver stator core 32 to the inner peripheral surface 22h of the cylindrical wall 22g, the resolver stator core 32 is directly connected to the case 22 instead of the holding portion 36. Positioning has improved the accuracy.

  For this reason, in the present embodiment, the shielding portion 35a of the shielding plate 35 that covers the resolver stator core 32 and the cylindrical wall 22g that abuts the tip 22i on the outer peripheral surface 32c of the resolver stator core 32 are in the axial direction (the same figure). Then, it will overlap in the horizontal direction). Therefore, the size of the gap G is set in consideration of the thickness t of the cylindrical wall 22g, and further, the gap g (g> 0) can be secured between the cylindrical wall 22g and the shielding portion 35a. Thereby, the electromagnetic noise generated at the coil end 5 can be further prevented from entering the resolver stator core 32. Unlike the case illustrated in FIG. 4, in the case where the cylindrical wall 22g does not enter the inside of the shielding portion 35a, it is not necessary to consider the thickness t of the cylindrical wall 22g. The gap G between the outer peripheral surface 32c and the shielding part 35a may simply be G> 0. Here, the size of the gaps g and G depends on space restrictions with other members and the like, and the material of the shielding plate 35. Therefore, the sizes of the gaps g and G may be appropriately set based on experiments or the like.

  Moreover, if the end edge 35c of the shielding part 35 corresponds to or exceeds the end part 5a of the coil end 5, the shielding effect of electromagnetic noise can be further enhanced.

  Furthermore, since the shielding effect of electromagnetic noise can be structurally enhanced by providing the gaps G and g as described above, the shielding plate 35 is made of, for example, a general steel plate instead of an electromagnetic steel plate. Therefore, it is possible to reduce the cost. In addition, since the workability is improved by replacing the electromagnetic steel sheet with a general steel sheet, the electromagnetic steel sheet has a shape of the shielding plate 35 as described above, that is, a shape having a tubular portion and a flange-like portion. However, it is difficult to form by drawing by press working, whereas this is possible with a general steel plate. The shape of the shielding plate 35 as described above facilitates integral molding with the synthetic resin holding portion 36.

  In the above-described embodiment, the case where the shielding plate 35 is formed of a general steel plate has been described. However, the shielding plate 35 may be made of any other material as long as it is a magnetic material. it can. Furthermore, not only a magnetic body but conductors other than a magnetic body (for example, aluminum, copper, etc.) can be used. When the shielding plate 35 is formed of a conductor, an eddy current is generated in the conductor due to electromagnetic noise, and this eddy current is generated so as to suppress the electromagnetic noise. Therefore, the electromagnetic noise entering the resolver stator core 32 is reduced. Is possible.

DESCRIPTION OF SYMBOLS 1 Drive part 2 Motor 5 Coil end 22 Motor case (case)
30 Resolver 32 Resolver Stator Core 33 Resolver Stator Coil 34 Resolver Stator 35 Shielding Plate 35a Shielding Section 35b Leg 36 Holding Section

Claims (5)

In the electromagnetic shielding structure of the resolver that detects the rotation angle of the motor,
A resolver stator core comprising a plurality of electromagnetic steel plates and a resolver stator core wound around the resolver stator core;
A shielding plate that is disposed between the motor and the resolver stator core and shields electromagnetic noise generated from the motor;
The shielding plate includes a shielding portion disposed with a gap between the resolver stator core and a leg portion formed integrally with the shielding portion and supported on the resolver stator side.
An electromagnetic shielding structure for a resolver. The gap is set to a size sufficient to ensure magnetic insulation between the shielding plate and the resolver stator core.
The electromagnetic shielding structure for a resolver according to claim 1. The shielding plate is integrally formed with a synthetic resin annular holding portion together with the resolver stator via the legs in a state where the shielding portion holds the gap between the shielding portion and the resolver stator core. ,
The electromagnetic shielding structure for a resolver according to claim 1 or 2. The resolver stator core is directly positioned on a motor case made of a non-magnetic material, and the resolver stator is attached to the motor case via the holding portion,
The shielding plate is made of a magnetic material.
The electromagnetic shielding structure for a resolver according to claim 3. The resolver is disposed on the inner diameter side of the coil end of the motor,
The shielding portion of the shielding plate is disposed so as to cover the outer peripheral surface of the resolver stator core.
The electromagnetic shielding structure for a resolver according to claim 3 or 4,

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