JP3300279B2 - motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor and, more particularly, to a vibration damping structure for a motor capable of reducing vibration of the motor during rotation.

[0002]

2. Description of the Related Art Conventionally, a motor housing is known in which a plate-shaped or dish-shaped bracket is attached to an opening of a bottomed cylindrical metal case. As this mounting form,
There is one in which the bracket is received by a fitting step formed in an opening of a case, and an opening edge is bent inward by caulking or the like.

However, in such a mounting form,
A portion of the opening edge that is not caulked may cause stress deformation, and a gap may be formed between the case and the bracket. Then, vibration generated when the rotor of the motor rotates is transmitted to the bracket or the case via the rotating shaft and the bearing, and the bracket may rattle to the case.
Such rattling causes noise.

A technique for solving the above problem is disclosed in Japanese Patent Application Laid-Open No. 8-331789. That is, the bracket is formed so that the diameter of the bracket is slightly larger than the opening diameter of the metal case, and a groove is formed all around the outer periphery of the bracket. Then, when such a bracket is press-fitted into the case opening, the outer peripheral portion can be elastically deformed in the radial direction by the groove, so that the bracket is attached in a state of being tightly attached without distorting the case opening. Therefore, since the bracket does not rattle with respect to the case, noise due to the rattling is reduced.

[0005]

However, in the above-mentioned bracket, since the outer peripheral portion in which the groove is formed is thin, the axial strength of the groove decreases. for that reason,
The bracket is easily bent in the axial direction. Then, the bracket is vibrated in the axial direction by vibration generated when the rotor rotates, and this vibration becomes a new cause of noise generation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a motor capable of reliably reducing the generation of noise.

[0007]

In order to solve the above-mentioned problems, a first aspect of the present invention provides a motor housing comprising a metal case and a dish-shaped cover fitted into an opening of the case. And a bearing fixed to a bearing holding portion provided in the motor housing, and a rotor having a rotating shaft rotatably supported with respect to the bearing, wherein the cover includes a metal bracket. And the bracket
A resin portion covering the case, and a tapered portion having a diameter gradually increasing toward the opening side is formed in the opening of the case over the entire circumference, and the bracket is pressed into the tapered portion in a state of being in close contact with the tapered portion. And fixed.

According to a second aspect of the present invention, a metal case is provided.
And a dish-shaped cover fitted into the opening of the case.
And a motor housing provided on the motor housing.
A bearing fixed to the bearing holding portion,
And a rotor whose rotating shaft is rotatably supported.
In the motor, the bearing holding portion is made of a vibration isolating member,
The bearing holder is integrally formed with the motor housing.
In addition, the cover includes a metal bracket and the bracket.
And a resin part for covering the socket,
The part has a taper whose diameter gradually increases toward the opening side.
The tapered part is formed over the entire circumference, and the tapered part is
The racket was press-fitted in a tightly contacted state and fixed.

The invention described in claim 3 is the first or second invention.
3. The motor according to claim 1, wherein the bracket has an outer periphery.
The surface was shaved .

The invention according to claim 4 is the invention according to claim 2.
In the above motor, the bearing is knurled on its outer peripheral surface.
After working, the bearing was pressed into the bearing holding portion.

Therefore, according to the first aspect of the present invention,
A tapered portion whose diameter gradually increases toward the opening side is formed in the opening of the case over the entire circumference, and a bracket is press-fitted into the tapered portion and fixed. Then, the bracket is fixed to the case in a state where the outer peripheral portion is in close contact with the case opening over the entire periphery. Therefore, the generation of a gap between the case and the bracket can be prevented, so that noise generated between the case and the bracket can be reduced even when the rotor rotates. Moreover, since it is not necessary to form a thin groove or the like in the bracket, the strength of the bracket does not decrease. Therefore, vibration in the axial direction of the bracket is reduced, and noise generated by this vibration can be reduced. As a result, noise generated by the rotation of the rotor can be reliably reduced.

[0012]

According to the second aspect of the present invention, the bearing holding portion is made of a vibration isolating member and is integrally formed with the motor housing. Then, even if the vibration generated due to the rotation of the rotor is transmitted to the bearing via the rotating shaft, the vibration of the bearing is attenuated by the bearing holding portion. Further, a tapered portion having a diameter gradually increasing toward the opening side is formed in the opening of the case over the entire circumference, and a bracket is press-fitted into the tapered portion and fixed. Then, the bracket is fixed to the case in a state where the outer peripheral portion is in close contact with the case opening over the entire periphery. Further, the vibration of the bearing is attenuated by the bearing holding portion. Therefore, the generation of the gap between the case and the bracket can be reduced, and the vibration of the case and the bracket can be reduced, so that the noise generated between the case and the bracket can be reduced. Further, since it is not necessary to form a thin groove or the like in the bracket, the strength of the bracket does not decrease. Therefore, vibration in the axial direction of the bracket is reduced, and noise generated by this vibration can be reduced. As a result, noise generated by rotation of the rotor can be reduced more reliably.

According to the third aspect of the present invention, since the outer peripheral surface of the bracket is subjected to shaving, the finished surface roughness of the outer peripheral surface is improved. Then, the bracket is fixed to the case in a state where the outer peripheral portion is securely in contact with the case opening over the entire periphery. Therefore, the occurrence of a gap between the case and the bracket can be reliably prevented, so that noise generated between the case and the bracket can be further reduced even when the rotor rotates.

According to the fourth aspect of the present invention, the outer peripheral surface of the bearing is subjected to knurling, and the bearing is pressed into the bearing holding portion. Therefore, the bearing can be reliably held by the bearing holding portion.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a motor 1
2 is a cross-sectional view of FIG.
FIG. 3 is a sectional view taken along line XX. FIG. 1 is a sectional view taken along line YY in FIG.

The motor housing 2 of the motor 1 includes a cylindrical metal case 3 having one end closed, and a dish-shaped cover 4 attached to the opening 3a of the metal case 3. At the center of the end face 3b of the metal case 3, an insertion hole 3c is formed by press working. A substantially cylindrical bearing holding portion 5 protruding outside the metal case 3 is provided at a portion where the insertion hole 3c is formed. The bearing holder 5 is made of synthetic resin (elastomer), and is outsert molded so as to be integrated with the metal case 3.

As shown in FIG. 4, a steel-based sintered metal bearing (hereinafter simply referred to as a metal bearing) 6 having a knurled outer surface 6a is press-fitted into the bearing holding portion 5 as shown in FIG. At this time, even if the metal bearing 6 is press-fitted into the bearing holding portion 5, the holding portion 5 is made of a synthetic resin, so that the shaft support hole 6b of the metal bearing 6 is not deformed. Moreover, since the outer peripheral surface 6 a of the metal bearing 6 is knurled, the metal bearing 6 is securely held by the bearing holding portion 5.

A magnet 7 is fixed to the inner peripheral surface of the cylindrical portion 3d of the metal case 3. A rotor 8 is rotatably supported inside the magnet 7. That is, the rotor 8 is provided with a rotating shaft 8a, and the rotating shaft 8a is inserted into and supported by the shaft support hole 6b of the metal bearing 6.

At the opening 3a of the metal case 3, a step 3e for attaching the cover 4 is formed. As shown in FIG. 6, the step portion 3e has a deepest diameter L.
1. The diameter L of the shallowest part is larger than the diameter L1 of the deepest part.
2, which is formed in a so-called tapered shape in which the diameter gradually increases from the deepest portion to the shallowest portion. In addition, as shown in FIG. 2, six caulking portions 3f are provided at equal intervals in the opening 3a.

The cover 4 comprises a substantially disk-shaped bracket 9 made of metal as shown in FIG. 5 and a resin portion 10 made of a synthetic resin (elastomer) for covering the bracket 9. This resin portion 10 is provided with a bracket 9
Is a vibration isolating member for preventing the vibration of the member.

The outer peripheral surface of the bracket 9 is subjected to a so-called shaving process for improving the finished surface roughness. In the center of the bracket 9, an insertion hole 9a is provided.
Are formed. Further, the bracket 9 has two notches 9b which are cut out in a substantially square shape from the outer peripheral portion.
The notch 9b is formed at a location where the notch 9b is located across the insertion hole 9a. The insertion hole 9a and the notch 9b of the bracket 9 are formed by press working.

The bracket 9 and the resin portion 10
The bracket 9 is formed by insert molding so that the two are integrated. At the same time, terminals 11 for supplying an external power to the rotor 8 penetrate the cover 4 at the notches 9b of the bracket 9 as shown in FIG. Inserted. The terminal 11 is disposed at a predetermined position of the resin portion 10 that does not contact the notch 9b. That is, the resin portion 10 keeps the terminal 11 and the bracket 9 insulated. Each terminal 11 has a brush 12 attached thereto. The brush 12 is a commutator 8b of the rotor 8.
, And the power from the terminal 11 is supplied to the commutator 8 b to generate a rotating magnetic field in the rotor 8.

The resin portion 10 is formed with a substantially cylindrical bearing holding portion 10a projecting outside the cover 4 at a position corresponding to the insertion hole 9a of the bracket 9.
As shown in FIG. 4, the same metal bearing 6 as described above is press-fitted into the bearing holding portion 10a, and the rotating shaft 8a is rotatably supported by a shaft support hole 6b.

As shown in FIG. 6, the cover 4 has a diameter L at the deepest part of the step 3e of the metal case 3.
A diameter L larger than 1 and smaller than the diameter L2 of the shallowest part
3 is formed. The cover 4 is press-fitted into a step 3e formed in the opening 3a of the metal case 3 at the time of assembly. At this time, the outer peripheral surface of the cover 4 (bracket 9) is in close contact with the step portion 3e over the entire circumference. Then, in this state, the cover 4 is fixed to the step portion 3e by the caulking portion 3f of the metal case 3.

The motor 1 thus configured is connected to the terminal 11
When external power is supplied to the brush 12, the power is supplied to the brush 12.
To the commutator 8b. Then, based on this power supply, a rotating magnetic field is generated in the rotor 8, and the rotor 8 is rotated.

At this time, since the metal bearing 6 supporting the rotating shaft 8a is held by the bearing holding portions 5, 10a made of resin, the vibration generated with the rotation of the rotor 8 is transmitted through the rotating shaft 8a. The vibration of the bearing 6 is attenuated by the bearing holding portions 5 and 10a even if the vibration is transmitted to the metal bearings 6 through the bearings. Therefore, in the present embodiment, the propagation of the vibration of the rotor 8 to the metal case 3 and the bracket 9 is suppressed.

Further, since the cover 4 (bracket 9) is attached in a state in which its outer peripheral portion is in close contact with the step portion 3e of the metal case 3 over the entire circumference, the bracket 9 is attached to the metal case 3. The bracket 9 is attached without any gaps, and rattling of the bracket 9 is prevented. Therefore, in the present embodiment, noise generated between the bracket 9 and the metal case 3 is prevented.

As described above, in this embodiment,
Insertion holes 3c and 9a are formed in the metal case 3 and the bracket 9 by press working, respectively.
The bearing holding portions 5 and 10a were integrally formed of synthetic resin in the portion 9a, and the metal bearings 6 were press-fitted into the bearing holding portions 5 and 10a, respectively.

Assuming that the metal case 3 and the bracket 9
When a bearing holding portion is formed by drawing or burring, and a metal bearing 6 is pressed into the bearing holding portion,
The shaft support hole 6b of the metal bearing 6 may be deformed into an elliptical shape or the like. In such a case, when the rotor 8 rotates, the rotation shaft 8a of the rotor 8 moves in the shaft support hole 6b, and this causes vibration. Therefore, in order to reduce the vibration, it is possible to solve the problem by increasing the processing accuracy of the drawing process or the burring process and improving the accuracy such as the inner diameter and the roundness of the bearing holding portion. In addition, the manufacturing cost of the bracket 9 increases.

On the other hand, in the present embodiment, the bearing holding portions 5
Since the metal 10a is made of a synthetic resin, even if the metal bearing 6 is press-fitted into the bearing holder 5, the shaft support hole 6b of the metal bearing 6 is not deformed. Therefore, since the rotating shaft 8a rotates stably in the shaft supporting hole 6b of the metal bearing 6,
The vibration generated between the rotating shaft 8a and the metal bearing 6 is suppressed to a small level.

Further, as described above, since the insertion holes 3c and 9a formed in the metal case 3 and the bracket 9 do not directly support the metal bearing 6, the accuracy of the insertion holes 3c and 9a such as the inner diameter and the roundness. It is not necessary to improve (the working accuracy of the press working). Moreover, since the insertion holes 3c and 9a are formed by pressing, the processing steps can be simplified as compared with drawing or burring.

As described above, this embodiment has the following features. (1) A so-called tapered step portion 3 having an opening 3a of the metal case 3 whose diameter gradually increases toward the opening side.
e is formed over the entire circumference. The cover 4 is press-fitted into the step 3e and fixed. Then
The cover 4 (bracket 9) is fixed to the metal case 3 in a state where its outer peripheral portion is in close contact with the step portion 3 e of the metal case 3 over the entire circumference. Therefore, since the play of the bracket 9 against the metal case 3 can be prevented, noise generated between the case 3 and the bracket 9 can be reduced even when the rotor 8 rotates. Moreover, since it is not necessary to form a thin groove or the like in the bracket 9 unlike the conventional case, the strength of the bracket 9 does not decrease. Therefore, the axial vibration of the bracket 9 is reduced, and the noise generated by this vibration can be reduced.

(2) In the present embodiment, the metal case 3 and the bracket 9 are inserted into the through holes 3 respectively.
c, 9a are formed by press working, and the respective insertion holes 3c, 9a are formed.
The bearing holding portions 5 and 10a were integrally formed of synthetic resin in the portions of the above, and the metal bearings 6 were press-fitted into the bearing holding portions 5 and 10a respectively. Therefore, even if the vibration generated with the rotation of the rotor 8 is transmitted to the metal bearing 6 via the rotation shaft 8a,
The vibration of the bearing 6 is attenuated by the bearing holding parts 5, 10a. Therefore, the rattling of the bracket 9 against the metal case 3 can be reduced, so that noise generated between the case 3 and the bracket 9 can be reduced. As a result, noise generated by the rotation of the rotor 8 can be reduced more reliably.

(3) The metal case 3 and the bracket 9
Since the bearing holders 5 and 10a are integrally formed with the bearing, the assembly work of the bearing holders 5 and 10a can be omitted.

(4) Further, since the insertion holes 3c and 9a formed in the metal case 3 and the bracket 9 do not directly support the metal bearing 6, the accuracy of the insertion holes 3c and 9a such as the inner diameter and the roundness is determined. It is not necessary to improve the processing accuracy). Moreover, since the insertion holes 3c and 9a are formed by press working, the working process can be relatively simplified.

(5) The outer peripheral surface of the bracket 9 is shaved. Therefore, the finished surface roughness of the outer peripheral surface of the bracket 9 is improved. Then, the bracket 9 is fixed to the metal case 3 in a state where its outer peripheral portion is securely adhered to the step portion 3 e of the metal case 3 over the entire circumference. Therefore, since the play of the bracket 9 against the metal case 3 can be reliably prevented, the noise generated between the metal case 3 and the bracket 9 can be further reduced even when the rotor 8 rotates.

(6) The outer peripheral surface 6a of the metal bearing 6 is knurled. Therefore, each bearing holding part 5,
The metal bearing 6 can be securely held with respect to 10a.

The embodiment of the present invention may be modified as follows. In the above embodiment, a tapered step portion 3e is formed in the opening 3a of the metal case 3 over the entire circumference, the cover 4 (bracket 9) is pressed into the step portion 3e, and the metal case 3 and the bracket 9 are formed. On the other hand, the bearing holders 5 and 10a are integrally formed of synthetic resin, but the cover 4 (bracket 9) is pressed into the step 3e of the metal case 3 or the bearing holder 5 is attached to the metal case 3 and the bracket 9. ,
Any one of the forms in which the 10a is integrally molded may be used. Although the bearing holders 5 and 10a are integrally formed on the metal case 3 and the bracket 9, the bearing holder may be provided on only one of the metal case 3 and the bracket 9.

In the above embodiment, the metal bearing 6 is press-fitted into the bearing holders 5, 10a, but may be changed to a radial bearing other than the metal bearing, for example, a radial ball bearing. In the above embodiment, the bearing holders 5 and 10a are made of synthetic resin, but may be made of other vibration isolating members such as rubber.

In the above embodiment, the outer peripheral surface of the bracket 9 is subjected to the shaving process. However, the shaving process is not particularly required. In the above embodiment, as shown in FIG.
Although the outer peripheral surface 6a is subjected to knurling, the shape is not limited to that shown in FIG. 4 as long as the metal bearing 6 can be securely held on the bearing holding portions 5, 10a.
In addition, this processing need not be particularly performed.

The technical ideas other than the claims that can be grasped from the above embodiments will be described below together with their effects. (A) The motor according to any one of claims 2 to 4 , wherein the vibration isolating member forming the bearing holding portion is made of a synthetic resin. Even with this configuration,
The same operation and effect as the invention according to claims 2 to 4 are obtained.

[0043]

As described in detail above, according to the present invention,
It is possible to provide a motor capable of surely reducing generation of noise.

[Brief description of the drawings]

FIG. 1 is a sectional view of a motor according to an embodiment.

FIG. 2 is a view taken in the direction of arrow A in FIG. 1;

FIG. 3 is a sectional view taken along line XX in FIG. 2;

FIG. 4 is a perspective view showing a bearing.

FIG. 5 is a plan view showing a bracket.

FIG. 6 is an enlarged sectional view of a main part of the motor.

[Explanation of symbols]

2 ... motor housing, 3 ... metal case as case, 3a ... opening, 3e ... step portion as taper portion,
5, 10a: bearing holding portion, 6: metal bearing as a bearing, 8: rotor, 8a: rotating shaft, 9: bracket.

Continuation of the front page (56) References JP-A-63-171144 (JP, A) JP-A-5-95165 (JP, U) JP-A 64-30653 (JP, U) JP-A-58-78757 (JP , U) Japanese Utility Model 3-70052 (JP, U) Japanese Utility Model 58-3762 (JP, U) Japanese Utility Model 63-187556 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB Name) H02K 5/24 H02K 5/04

Claims (4)

(57) [Claims] 1. A metal case (3) and said case (3)
A motor housing (2) composed of a dish-shaped cover (4) fitted into the opening (3a) of the motor housing (2) and a bearing holder (5, 10a) provided in the motor housing (2). In a motor provided with a bearing (6) and a rotor (8) whose rotation shaft (8a) is rotatably supported with respect to the bearing (6), the cover (4) includes a metal bracket ( 9)
And a resin portion (10) for covering the racket (9). The opening (3a) of the case (3) has a tapered portion (3e) gradually increasing in diameter toward the opening side over the entire circumference. A motor, wherein the bracket (9) is press-fitted and fixed to the tapered portion (3e) in a state where the bracket (9) is in close contact therewith. 2. A metal case (3) and said case (3)
Or a dish-shaped cover (4) fitted into the opening (3a)
A motor housing (2), and a bearing holder provided in the motor housing (2)
A bearing (6) fixed to (5, 10a), and a rotating shaft (8a) thereof can rotate with respect to the bearing (6).
And a rotor (8) supported by the bearing , the bearing holding portions (5, 10a) are made of a vibration isolating member, and
Of the bearing housing (5, 10a) of the motor housing
The cover (4) is integrally formed with the metal bracket (9) and the cover (4).
A resin portion (10) for covering the racket (9), and an opening (3a) of the case (3)
The entire circumference of the tapered portion (3e) whose diameter gradually increases toward
And the tapered portion (3e) is
It is specially noted that the
Motor. 3. A motor according to claim 1, wherein
The bracket (9) has a shaving part on its outer peripheral surface.
A motor that has been engineered. 4. A motor according to claim 2, wherein said bearing (6) is knurled on its outer peripheral surface (6a).
And the bearing (6) is connected to the bearing holding portions (5, 10).
A motor which is press-fitted in a).