JP2003032989A - Resolver-fixing structure of brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resolver fixing structure, which enables precise and easy fixing at a prescribed position by preventing positional deviations in the peripheral direction of a stator of a resolver. SOLUTION: A detection rotor 31 of the resolver 30 is fixed to a rotating shaft 16 of the brushless motor 11. The section of the rotor 31 is almost elliptical in shape. A detection stator 32 of the resolver 30 is accommodated in an accommodation part 41 of an end plate 14 with a part protruding. The stator 32 is made to abut against fixing members, which are arranged in three portions at an equal interval on a circumference and pressed against the end plate 14 by fastening bolts 46, thereby being fixed. In the peripheral part of the stator 32, protruding parts 51 are formed protruding in the radial direction, at positions facing the fixing members 45 via the shaft 16. The protruding parts 51, accommodated in accommodation recessed parts 52 of the end plate 14, are clamped by a pair of adjusting bolts 55 abutting against both side surfaces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resolver fixing structure for a brushless motor.

[0002]

2. Description of the Related Art In driving a brushless motor, it is necessary to supply a sinusoidal drive voltage in order to obtain smooth rotation with less torque ripple. A variable reluctance resolver, for example, is used as a rotation angle sensor for obtaining a driving signal therefor.

As a variable reluctance type resolver, for example, there is one which is disclosed in Japanese Patent Laid-Open No. 6-2133614. The variable reluctance resolver of this publication detects the rotation angle of the rotor by utilizing the fact that the well-known gap permeance composed of the rotor and the stator fluctuates sinusoidally as the rotor rotates. However, the angle detection is greatly affected by the dimensional accuracy of each part, the mounting accuracy, and the like. In particular, if positional deviation (angular deviation) occurs in the circumferential direction between the rotor and the stator during assembly, the accuracy will deteriorate significantly. Therefore, when assembling the resolver to the brushless motor, it is important to fix the resolver at a predetermined position with high accuracy.

Therefore, it is necessary to have an assembling method and structure that do not cause the above-mentioned factors when fixing. As an assembling method, for example, a jig is used to prevent a positional deviation in the circumferential direction between the rotor and the stator, and then the stator 61 is fixed to the brushless motor with an adhesive as shown in FIG. There is a method of adhering to the case 62.

There is also a method of fixing the stator to the case by bolting. For example, with respect to the positional deviation between the rotor and the stator in the circumferential direction, an elongated hole extending in the circumferential direction is formed in the bolt tightening portion of the stator for adjustment in a later step. In the subsequent step, the bolt is loosened, the stator is moved in the circumferential direction along the elongated hole to adjust the angle, and after the angle adjustment, the bolt is tightened again to fix the stator to the case.

[0006]

However, in the assembling method by bolting as described above, since the stator is directly operated and moved, fine adjustment of the positional deviation is not easy. In addition, since the misalignment may occur again when re-tightening the bolt after the adjustment, the reliability is low, and after re-tightening the bolt, it is necessary to check again whether the misalignment occurs. There is. Therefore, this method requires a large number of adjustment steps. Further, there is a possibility that the stator may be displaced in the circumferential direction due to the loosening of the bolt, and the reliability is low.

In addition, the method of adhering with an adhesive is costly and labor-intensive, and in addition to the protrusion and dripping of the adhesive, the strength is deteriorated due to heat deterioration and the like, so that the life is limited. Further, there is a problem that the angle cannot be adjusted in the subsequent process.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a brushless motor which can prevent the stator of the resolver from being displaced in the circumferential direction and can be accurately and easily fixed at a predetermined position. It is to provide a resolver fixing structure.

[0009]

In order to achieve the above object, the invention according to claim 1 is a resolver fixing structure for a brushless motor, wherein a rotor of the resolver is fixed to a rotating shaft of the brushless motor. The stator of the resolver is fixed to the case of the brushless motor by fixing means arranged at one or more predetermined portions, and a protrusion is formed on a peripheral portion of the stator at a position different from the predetermined portion. The gist is that the case holds an adjusting means using a screw, which engages with the protrusion and can adjust the position of the protrusion in the circumferential direction.

According to this invention, the stator of the resolver is
By operating the adjusting means, the position of the brushless motor is accurately adjusted in the circumferential direction by the action of the screw and is fixed to the case of the brushless motor. Therefore, the stator of the resolver can be accurately and easily fixed to the brushless motor at a predetermined position with a simple structure using screws. Further, even if the fixing means is loosened later, the stator is engaged with the adjusting means and its movement in the circumferential direction is restricted, so that the positional deviation is prevented.
Therefore, the reliability is high.

According to a second aspect of the present invention, in the invention according to the first aspect, the adjusting means is a pair of adjusting bolts for sandwiching the protrusion. According to this invention, when the screwing amount of one adjusting bolt is reduced and the screwing amount of the other adjusting bolt is increased, the protrusion is moved to the one adjusting bolt side by the pressing of the other adjusting bolt. , The stator is rotated in the circumferential direction. By the operation opposite to the above, the stator is rotated in the opposite direction. Therefore, the adjusting means can be easily realized with the adjusting bolt having a relatively small size.

According to a third aspect of the present invention, in the invention according to the first or second aspect, the protrusion and the adjusting means are opposed to each other with the predetermined portion interposed therebetween with respect to the rotary shaft. The summary is that it is located in. According to the present invention, for example, when three fixing means are arranged at equal intervals in the circumferential direction, the protrusion and the adjusting means are provided between the fixing means without any trouble.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1A is a schematic partial sectional view of a brushless motor, and FIG. 1B is a schematic sectional view taken along line IB-IB of FIG. 1A. 2A shows a partially enlarged view of the detection stator, and FIG. 2B shows an enlarged view of a main part of the detection stator.

As shown in FIG. 1A, the case 12 of the brushless motor 11 is a case body 13 having a substantially bottomed cylindrical shape.
And the end plate 14. Case 12
The bearing 1 arranged at the center of the end plate 14.
The rotation shaft 16 is rotatably supported via the shaft 5 and a bearing (not shown) arranged at the center of the bottom (not shown) of the case body 13.

A drive stator 18 of the brushless motor 11 is attached to the inner peripheral surface of the case body 13.
A drive rotor 19 is attached to a portion of the rotary shaft 16 facing the drive stator 18 so as to be rotatable integrally with the rotary shaft 16. The drive stator 18 has a drive coil 20 for generating a magnetic force that drives the drive rotor 19.

A detection rotor 31 as a rotor of the resolver 30 is attached to the end of the rotary shaft 16 closer to the end plate 14 than the drive rotor 19. End plate 14
The resolver 30 at a position facing the detection rotor 31.
The detection stator 32 as a stator of is attached.

The detection rotor 31 is constructed by laminating a plurality of sheets 31a made of thin steel plates. The detection rotor 31 is fitted into a key 33 embedded in the rotary shaft 16 so that it can rotate integrally with the rotary shaft 16.
As shown in FIG. 1B, the detection rotor 31 is formed in a substantially elliptical cross section.

Like the detection rotor 31, the detection stator 32 has a laminated structure in which a plurality of sheets 32a made of thin steel plates are laminated. As shown in detail in FIG. 2A, the detection stator 32 includes an annular portion 35 and a plurality of salient poles 36 protruding inside the annular portion 35. A winding is wound around each salient pole 36 to form a coil 37. Note that, in FIG. 1B, the salient pole 36 and the coil 37 are schematically illustrated. In this embodiment, the thickness of the detection stator 32 (thickness excluding the coil 37) is formed thinner than the thickness of the detection rotor 31.

Inside the end plate 14, a recess 40 having a circular cross section is formed. A housing 41 for housing the detection stator 32 is formed in a step shape near the opening of the recess 40 in the end plate 14. Further, an annular projection 42 is formed in the end plate 14 so as to project in the axial direction at a portion outside the opening of the recess 40.

The detecting stator 32 is accommodated in the accommodating portion 41, and a part of the detecting stator 32 protrudes from the accommodating portion 41. The annular protrusion 42 has a plurality of detection stators 32 attached to the end plate 14 (in this embodiment, 3 or more).
The individual mounting members 45 are arranged at predetermined positions on the circumference at equal intervals. The mounting member 45 is formed in a U-shaped cross section. The mounting member 45 has the first end portion of the annular portion 3 of the detection stator 32 in a state of straddling the annular protrusion 42.
5 (outer side portion of the detection stator 32), and the second end portion is in contact with the end surface of the end plate 14 outside the annular protrusion 42.

A through hole for a bolt is formed in the center of the mounting member 45. The mounting member 45 has a bolt 46 inserted into the through-hole through a washer, so that the annular projection 4
The bolts 46 are screwed into the screw holes 42a formed in the second plate 2 to be supported by the end plate 14. The mounting member 45 and the bolt 46 constitute a fixing means. The detection stator 32 is axially pressed by a mounting member 45 that abuts the annular portion 35, and the end plate 1
It is supported by 4.

The screw hole 42a is formed in the end plate 1
4 is a through hole. The tip of the bolt 46 is an engaging hole 46 as an engaging portion with which the tip of a jig such as a driver (not shown) inserted through the screw hole 42a can be engaged.
a is formed.

At the peripheral portion of the detection stator 32, a position (FIG. 1 (b)) which faces the predetermined mounting member 45 (upper mounting member 45 in FIG. 1B) with the rotary shaft 16 interposed therebetween.
A protrusion 51 is formed so as to project in the middle and the lower side). The protrusion 51 is formed in a block shape on the predetermined sheet 32a, and is formed so as to extend in the radial direction.

An accommodation recess 52 is formed in the end plate 14, and a protrusion 51 is accommodated in the accommodation recess 52. The housing recess 52 is formed to be larger in the circumferential direction than the protrusion 51.

The end plate 14 is formed with a screw hole 53 communicating with the accommodation recess 52. 2 screw holes 53
The two screw holes 53 are individually formed and are arranged on a straight line that is substantially orthogonal to the projecting direction of the protrusion 51 in the plane orthogonal to the rotation shaft 16. The screw hole 53 communicates with a recess 54 formed in the end plate 14 on the side opposite to the accommodation recess 52.

The adjusting bolt 5 is provided in each screw hole 53.
5 is screwed. The tip of each adjustment bolt 55 is in contact with the side surface of the protrusion 51. That is, both side surfaces of the protrusion 51 are in contact with the tips of the adjusting bolts 55 facing each other. The head of the adjusting bolt 55 (the portion on the concave portion 54 side)
Has an engaging hole 55a into which an unillustrated driver or the like can be engaged.
Are formed.

A hole 56 is formed in the case body 13 at a portion corresponding to the straight line where the screw hole 53 is arranged. Next, a method for mounting the stator of the resolver having the above structure will be described.

First, the end plate 14 is the case body 1.
3, the detection stator 32 is housed in the housing portion 41 of the end plate 14, and each mounting member 45
Is arranged at a predetermined position of the annular protrusion 42, the bolt 46 is inserted into the through hole of the mounting member 45, and the screw hole 42a is temporarily tightened. By temporarily tightening the bolt 46, the detection stator 32 is axially abutted and supported by the mounting member 45 in the annular portion 35, and is temporarily fixed to the end plate 14.

At this stage, the detection stator 32 does not need to be accurately mounted at a predetermined mounting angle in the circumferential direction with respect to a predetermined reference position of the end plate 14, and
It should be assembled in the approximate position. The detection stator 32 is positioned in the radial direction by being brought into contact with the peripheral surface of the housing portion 41.

Next, a jig such as a driver is attached to the adjusting bolt 55.
Engaging the engaging hole 55a of the adjusting bolt 5 by operating the jig.
The amount of screwing of No. 5 is adjusted, and the detection stator 32 is rotated by moving the protrusion 51 that comes into contact with the adjustment bolt 55, and is adjusted so as to have a predetermined mounting angle in the circumferential direction. For example, in FIG. 1B and FIG. 2B, the screwing amount of the adjustment bolt 55 on the left side is reduced to adjust the adjustment bolt 5 on the right side.
When the screwing amount of 5 is increased, the protrusion 51 is pressed by the adjustment bolt 55 on the right side and moved to the left side. The movement of the protrusion 51 causes the detection stator 32 to rotate clockwise in the drawing. When the screwing amount of the adjusting bolt 55 is adjusted in the opposite manner to the above case, the detection stator 32 is rotated counterclockwise in the drawing.

By the adjustment of the adjusting bolt 55 as described above, the detection stator 32 is mounted at a predetermined mounting angle in the circumferential direction with respect to a predetermined reference position of the end plate 14. After the adjustment of the angular position of the detection stator 32 by the adjustment bolt 55, the bolt 46 is fully tightened to fix the detection stator 32 to the end plate 14.

If the detection stator 32 is found to be slightly displaced in the circumferential direction after the end plate 14 to which the detection stator 32 is fixed is assembled to the case main body 13, first, the end plate is detected. The screwdriver is inserted into the screw hole 42a from the outside of 14. Then, the bolt 46 is loosened by engaging the driver with the engaging hole 46a and operating the driver. Next, a driver is inserted into the hole 56 from the outside of the case main body 13 and engaged with the engaging hole 55a of the adjusting bolt 55 to operate to adjust the screwing amount of the adjusting bolt 55 to detect the protrusion 51 together with the protrusion 51. The position shift is corrected by moving the stator 32 in the circumferential direction. After that, the screwdriver is again inserted into the screw hole 42a to engage with the engagement hole 46a, the bolt 46 is tightened again, and the detection stator 32 is fixed to the end plate 14 again.

According to this embodiment, the following effects are obtained. (1) The protrusion 51 is provided on the detection stator 32 of the resolver 30.
The adjusting bolt 55 that abuts the protrusion 51 is screwed into the screw hole 53 of the end plate 14.
Therefore, by adjusting the screwing amount of the adjusting bolt 55, the detection stator 32 is rotated in the circumferential direction, and the detection stator 3 is rotated with respect to a predetermined reference position of the end plate 14.
It can be adjusted easily and accurately so that 2 can be mounted at a predetermined mounting angle.

(2) The detection stator 32 is restricted from moving in the circumferential direction by the projection 51 being sandwiched from both sides by the pair of adjusting bolts 55. Therefore, even if the bolt 46 is loosened, the detection stator 32 is prevented from being displaced in the circumferential direction with respect to the end plate 14. Therefore, the reliability is high.

(3) Since the detection stator 32, which is moved in the circumferential direction by the adjustment of the adjusting bolt 55, has a comparatively light weight, the adjusting bolt 55 can be made small in size.

(4) Since the adjusting bolt 55 has a small size, a finer screw pitch can be used. Therefore, fine adjustment in the circumferential direction of the detection stator 32 with respect to the end plate 14 becomes easier.

(5) The protrusion 51 and the adjusting bolt 55 are
Predetermined mounting member 45 (upper mounting member 4 in FIG. 1B)
5) to a position facing the rotary shaft 16 (FIG. 1).
(B) Middle and lower side). Therefore, the protrusion 5
The arrangement position of 1 and the adjusting bolt 55 can be secured between the other two mounting members 45 without any trouble.

(6) The adjustment bolt 5 is attached to the case body 13.
5, a hole 56 is formed on a straight line, and the screw hole 42a
Is formed in a through hole penetrating the end plate 14, and the engagement hole 46a is formed at the tip of the bolt 46.
Are formed. Therefore, after the end plate 14 to which the detection stator 32 is fixed is assembled to the case body 13, the positional deviation of the detection stator 32 in the circumferential direction can be corrected from the outside of the case 12 without removing the end plate 14 from the case body 13. ..

The embodiment is not limited to the above embodiment, but may be modified as follows. A configuration in which the detection stator 32 is adjusted so that the detection stator 32 is mounted at a predetermined mounting angle in the circumferential direction with respect to a predetermined reference position of the end plate 14 is arranged on the projection 51 formed on the detection stator 32 and the end plate 14. The adjustment bolt 55 is not limited to this. For example, a worm gear may be attached to the end plate, the detection stator 32 may be formed as a worm wheel, and the protrusion may be a gear portion of the worm wheel.

The protrusion 51 is not limited to be formed so as to extend in the radial direction of the detection stator 32.
The detection stator 32 may be formed so as to extend in the axial direction, and the adjustment bolt 55 may be attached so as to engage with the protrusion.

The protrusion 51 is not limited to be formed in a block shape on a predetermined sheet 32a, and for example, each sheet 32a of the detection stator 32 is formed with a protrusion having the same thickness as the sheet, and each protrusion is formed. The protrusion 51 may be formed by stacking the parts.

The mounting members 45 are not limited to being arranged at equal angular intervals. The detection stator 32 includes three mounting members 45 and bolts 4.
It is not limited to being fixed to the end plate 14 by means of 6, and may be fixed to the end plate 14 by means of a plurality of attachment members 45 other than one or three and bolts 46, for example.

The engagement hole 46a is not formed in the bolt 46, and the screw hole 42a does not have to penetrate the end plate 14. The technical ideas that can be understood from the above embodiments will be added below.

(1) In the invention described in claim 1,
The adjusting means is a worm gear, the stator is a worm wheel, and the protrusion is a gear portion of the worm wheel.

(2) In the invention described in claim 2 or 3, the projection is formed so as to extend in the radial direction. (3) Claims 2, 3 and the technical idea (2)
In the invention described in any one of 1,
It is composed of a bottomed cylindrical case body and an end plate, the stator is fixed to the inner surface of the end plate, the fixing means is composed of a mounting member and a bolt, and the tip portion of the bolt. An engaging portion with a jig is formed on the end plate, and a screwing portion to which the bolt is screwed is formed on the end plate as a through hole penetrating the end plate, Has a hole for adjusting the adjustment bolt from the outside at a predetermined position in a state where the end plate with the stator fixed is attached to the case body.

(4) In the invention described in any one of claims 1 to 3 and technical ideas (1) to (3), the stator is fixed to the case at an outer side portion. There is.

[0048]

As described in detail above, according to the inventions of claims 1 to 3, it is possible to prevent the displacement of the stator of the resolver in the circumferential direction and to accurately and easily determine the brushless motor. Can be fixed in position.

[Brief description of drawings]

FIG. 1A is a schematic partial sectional view of a brushless motor,
(B) is an IB-IB line schematic cross section of (a).

2A is a partially enlarged view of a detection stator, and FIG. 2B is an enlarged view of a main part of the detection stator.

FIG. 3 is a schematic partial sectional view of a conventional brushless motor.

[Explanation of symbols]

11 ... Brushless motor, 12 ... Case, 13 ... Case main body that constitutes the case, 14 ... Similarly end plate,
16 ... Rotation shaft, 30 ... Resolver, 31 ... Detection rotor as rotor of resolver, 32 ... Detection stator as stator of resolver, 45 ... Mounting member constituting fixing means,
46 ... Similarly bolts, 51 ... protrusions, 55 ... adjusting bolts.

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Claims (3)

[Claims] 1. A resolver fixing structure for a brushless motor, wherein a rotor of the resolver is fixed to a rotating shaft of the brushless motor, and a stator of the resolver is fixed by a fixing means arranged at one or more predetermined portions. It is fixed to a case of a brushless motor, and a protrusion is formed on a peripheral portion of the stator at a position different from the predetermined portion, and the case is engaged with the protrusion to circumferentially form the protrusion. A resolver fixing structure for a brushless motor, characterized in that an adjusting means using a screw capable of adjusting a position is held. 2. The resolver fixing structure for a brushless motor according to claim 1, wherein the adjusting means is a pair of adjusting bolts for holding the protrusion. 3. The projection according to claim 1 or 2, wherein the protrusion and the adjusting means are arranged at a position opposed to the predetermined portion with the rotation shaft interposed therebetween. Resolver fixing structure for brushless motor.