JPH11289735A - Brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brushless motor that can surely prevent noises which are produced when the rotor of the motor is rotated. SOLUTION: In a brushless motor, which is constituted in such a way that a rotor 6 is rotatably supported by a stator 2 fixed to a motor holder 1, the rotor 6 is rotationally driven by supplying an exciting current to the stator 2, a fixing plate 21 is formed at one end of a center piece 3 constituting the stator 2, and a boss section 22 is formed on the fixing plate 21. Then the boss section 22 is fixed to the motor holder 1 via a vibration proofing material 24a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless motor used as a blower motor of a vehicle air conditioner.

[0002]

2. Description of the Related Art In an outer rotor type brushless motor used as a blower motor of a vehicle air conditioner, a stator and a control board are fixed to a case member.
A large number of elements constituting an excitation circuit for generating a rotating magnetic field in the stator are mounted on the control board. A rotor formed so as to cover the stator is rotatably supported by the stator. When the stator is energized by the excitation circuit, the rotor is driven to rotate.

In such a brushless motor, an attractive force between a magnet bonded to a rotor and a stator coil,
Torque ripple occurs due to cogging torque, weight imbalance of the rotor itself, and the like, and as a result, the rotor vibrates and generates noise. Since the noise due to the vibration of the rotor tends to be larger than that of a DC motor with a brush of the same size, various measures described below have been proposed to reduce the noise.

(A) Measures to prevent vibration of the rotor from being transmitted to the motor mounting member on the vehicle side. When the vibration of the rotor is transmitted to the motor mounting member on the vehicle side via the center piece and the case member, the ducts resonate based on the vibration and generate noise. Further, when the case member vibrates, the control board vibrates based on the vibration and generates noise. Therefore, set the center piece to a hardness of 50
A configuration has been proposed in which the transmission of vibration from the center piece to the case member is prevented by fixing the case member to the case member via a vibration-proof material such as CR rubber (JIS-A).

In the brushless motor described in Japanese Patent Application Laid-Open No. Hei 8-9616, vibration from the insulating cover to the storage case is fixed by fixing the insulating cover to which the stator core is attached to the storage case via a cushioning material. There is disclosed a configuration for preventing the transmission of the information.

(B) Countermeasures to prevent the motor mounting member on the vehicle side from vibrating by making the rotor itself an anti-vibration structure. JP-A-4-236155 and JP-A-7-
No. 59315 discloses a rotor employing a vibration-proof structure.

[0007]

Problems with the measure (a). In the configuration in which the transmission of vibration from the center piece to the case member is prevented by a vibration-proof material such as rubber,
For the frequency of the vibration generated by the rotor, a hardness of 50 CR
Rubber cannot provide a sufficient vibration damping effect.
Therefore, in order to prevent the vibration of the case member from being transmitted to the motor mounting member on the vehicle side, if an anti-vibration material is further interposed between the case member and the motor mounting member, the number of working steps and the number of parts during assembly increase. There is a problem that costs increase.

Further, in order to obtain a sufficient vibration damping effect, C
If the hardness of the R rubber is set to be soft, it becomes difficult to secure the mounting accuracy between the center piece and the case member. And
When the mounting accuracy is reduced, the output characteristics of the motor are deteriorated due to a displacement between the sensor magnet attached to the rotating shaft of the rotor and the Hall element on the control board.

In the brushless motor described in Japanese Patent Application Laid-Open No. Hei 8-9616, since the vibration of the fixed shaft supporting the rotating shaft of the rotor is transmitted to the storage case, the generation of vibration and noise is sufficiently suppressed. Can not do.

Problems in the measure (b). JP-A-4-
In the rotor vibration isolation structure described in 236155, the rotor manufacturing process is complicated.

In the vibration damping structure for a rotor described in Japanese Patent Application Laid-Open No. 7-59315, it is necessary to fit the first yoke and the second yoke to the cup-shaped cushioning material, so that the rotor is assembled. The process becomes complicated.

It is an object of the present invention to provide a brushless motor capable of reliably preventing generation of noise due to rotation of a rotor.

[0013]

According to the first aspect of the present invention, a stator is fixed to a motor holder, a rotor is rotatably supported on the stator, and an exciting current is supplied to the stator so that the rotor is rotated. In a brushless motor that is driven to rotate, a fixed plate is formed at one end of a center piece that forms the stator, a boss is formed on the fixed plate, and the boss is fixed to the motor holder via a vibration isolator.

According to a second aspect of the present invention, in the first aspect, the vibration isolator is formed of a gel-like rubber or resin material. According to a third aspect of the present invention, the center piece constituting the stator is fixed to the motor holder via a vibration-proof material made of a gel-like rubber or resin material.

The invention described in claim 4 is the first to third aspects of the present invention.
In any one of the above, the vibration-proof material is formed in an annular shape in which the boss portion can be inserted, and a locking groove is formed at an axial center portion of an outer peripheral surface of the vibration-proof material, and the locking groove is formed in the locking groove. The centerpiece was positioned in the radial direction and the axial direction of the vibration-proof material with respect to the motor holder by fitting the mounting hole of the motor holder and clamping and fixing the vibration-proof material between the centerpiece and the mounting plate. .

The invention according to claim 5 is the invention according to claims 1 to 3
In any one of the above, the vibration-proof material is formed by sandwiching an O-ring formed of gel-like rubber or resin between a pair of annular plate-like vibration-proof materials.

The invention described in claim 6 is the first to third aspects of the present invention.
In any one of the above, the vibration damping material is formed integrally with the motor holder. According to a seventh aspect of the present invention, a vibration isolator is interposed between a yoke constituting the rotor and an output shaft of the rotor.

According to an eighth aspect of the present invention, in the seventh aspect, the vibration isolator is attached to a collar fixed to the output shaft, and the yoke is attached to the vibration isolator. Detent means are provided between the vibration member and the collar and between the vibration isolator and the yoke, so that the output shaft and the yoke cannot be relatively rotated.

According to a ninth aspect of the present invention, the yoke constituting the rotor and the fan rotatably supported on the output shaft of the rotor are connected via a vibration isolator so as to be relatively non-rotatable.
According to a tenth aspect of the present invention, the yoke constituting the rotor is formed of a damping steel plate.

According to the first aspect of the present invention, since the center piece is fixed to the motor holder via the vibration isolator, the vibration transmission path from the yoke which is the vibration source to the center piece which is the stator fixing portion is provided. Be shortened.

According to the second aspect of the present invention, the transmission of vibration from the centerpiece to the motor holder is suppressed by the vibration-proof material formed of gel-like rubber or resin material. According to the third aspect of the present invention, since the center piece is fixed to the motor holder via the vibration-proof material made of gel-like rubber or resin material, the center from the yoke which is the vibration source to the stator fixing portion is fixed. The vibration transmission path to the piece is shortened, and the transmission of vibration from the center piece to the motor holder is suppressed.

According to the fourth aspect of the present invention, the center piece is easily positioned with respect to the motor holder in the radial direction and the axial direction of the vibration isolator, and the transmission of vibration from the center piece to the motor holder is suppressed. .

According to the fifth aspect of the present invention, the center piece is easily positioned in the radial direction and the axial direction of the vibration isolator with respect to the motor holder by the O-ring and the plate-like vibration isolator. Transmission of vibration to the holder is suppressed.

According to the sixth aspect of the present invention, since the vibration isolator is formed integrally with the motor holder, the work of attaching the center piece to the motor holder becomes easy. According to the seventh aspect of the present invention, the transmission of vibration from the yoke to the output shaft is suppressed, so that the transmission of vibration from the yoke to other components of the motor is suppressed.

According to the eighth aspect of the present invention, the rotation preventing means prevents the idle rotation between the yoke and the output shaft.
According to the ninth aspect, transmission of vibration from the yoke to the fan is prevented.

According to the tenth aspect, the vibration of the yoke is suppressed.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a stator 2 is fixed to a motor holder 1 formed of a synthetic resin. The stator 2 includes a center piece 3, a core 4, and a winding 5 wound around the core 4.

A rotor 6 is rotatably supported by the stator 2. The rotor 6 includes a yoke 7, a plurality of magnets 8 fixed to the inner peripheral surface of the yoke 7, and an output shaft 9 which is press-fitted into the center of the yoke.
The output shaft 9 is rotatably supported by the center of the center piece 3 via bearings 10a and 10b,
A sirocco fan 11 is fixed to the tip of the output shaft 9.

A circuit board 1 is provided on the lower surface of the motor holder 1.
2 is fixed with one or a plurality of screws, and a large number of elements constituting an excitation circuit are mounted on the circuit board 12 thereof. When an exciting current is supplied from the exciting circuit to the winding 5, the rotor 6 is rotated, and the output shaft 9 is rotated with the rotation of the rotor 6. Therefore, when the exciting current is supplied to the winding 5, the rotation of the output shaft 9 and the rotation of the fan 1
1 is rotated to perform the blowing operation.

A disc-shaped sensor magnet 15 is fitted to the lower end of the output shaft 9, and a Hall element 16 is disposed on the circuit board 12 near the outer periphery of the sensor magnet 15. I have. The rotation angle of the rotor 6 is detected by detecting the magnetic flux of the sensor magnet 15 with the Hall element 16, and the excitation circuit controls the excitation current based on the detection signal.

The motor holder 1 has the circuit board 12
Is attached. The lower case 1
Reference numeral 7 denotes a synthetic resin similar to that of the motor holder 1 and is formed in a dish shape with its periphery hanging upward, and is formed to be thinner than the motor holder 1 in order to reduce the weight.
Then, the circuit board 12 is accommodated in an accommodation portion 18 formed between the motor holder 1 and the lower case 17.

The motor holder 1 has the fan 11
A blower case 19 that covers the periphery of is mounted. In the upper part of the blower case 19, an opening 20 is formed which is continuous with an introduction duct (not shown) for introducing air from outside or from the vehicle interior. On the side of the blower case 19, an air outlet (not shown) connected to the air duct is formed. Then, based on the rotation of the fan 11, the opening 20
Is introduced into the blower case 19 in a spiral shape to an air inlet, and is guided to a vehicle interior or an air conditioner via an air duct.

The stator 2 has a center piece 3
Is fixed to the motor holder 1. That is, the lower end portion of the center piece 3 is extended in a substantially disk shape in the circumferential direction to form the fixing plate 21, and the fixing plate 21 is formed with three boss portions 22 projecting downward at equal intervals. You.

A screw hole 23 is formed at the center of the boss portion 22, and a vibration isolator 24a is fitted around the boss portion 22. As shown in FIG. 2, the vibration isolator 24a
It is formed in an annular shape from a gel-like rubber or resin material having a hardness of 10 to 20 (JIS-A) (in this embodiment, a silicone rubber material having a JIS hardness of 20), and the central portion in the axial direction of the outer peripheral surface is reduced in diameter. Locking groove 25 is formed. The locking groove 25 has a width equal to the thickness of the motor holder 1.

The anti-vibration member 24a is fitted into the mounting hole 26a formed in the motor holder 1 at the locking groove 25, and the boss 22 is fitted into the center of the anti-vibration member 24a. ing. Further, the vibration isolator 2 fitted with the boss portion 22 is provided.
A mounting plate 27 is in contact with the lower surface of 4a, and a screw 28 passing through the mounting plate 27 from below the mounting plate 27 is screwed into a screw hole 23 of the boss portion 22, and the mounting plate 27 is fixed to the fixing plate. 21, and the vibration isolator 24 a is compressed between the fixing plate 21 and the mounting plate 27. At this time, the compression rate of the vibration isolator 24a is 10
The thickness of the vibration isolator 24a with respect to the height of the boss portion 22 is set so as to be about 20%.

Therefore, when the screw 28 is screwed into the screw hole 23, the boss 22 is attached to the mounting hole 26 of the motor holder 1.
1, the center piece 3 is fixed to the motor holder 1 in the vertical and horizontal directions in FIG.

A mounting hole 26b provided in the motor holder 1 between the bosses 22 is provided with the vibration isolating material 27.
The same vibration-proof material 24b as that of FIG.
Is arranged between the fixing plate 21 and the mounting plate 27 in a compressed state similarly to the vibration isolator 24a.

The characteristics of the vibration insulators 24a and 24b are shown in FIGS.
As shown in FIG. FIG. 3 shows the rotational angular velocity of the rotor 6 as ω,
When the angular velocity of the natural frequency of the rotor 6 is ωn, ω /
The relationship between ωn and the vibration transmissibility is shown. The vibration isolator 24a, 2
4b has a lower vibration transmissibility over the entire band of ω / ωn than CR rubber, which is a conventional vibration isolator, and has a lower resonance magnification even at the resonance point of the rotor 6 where ω / ωn is “1”. .

FIG. 4 shows the relationship between the rotation speed of the rotor 6, that is, the vibration frequency (rotor rotation speed) of the rotor 6, and the vibration transmissibility. The rotational speed of the vibration isolator 24a, 24b at the resonance point Q is lower than the range of the rotational speed of the rotor 6;
In all the bands of the operating speed range of the vibration isolator 24a, 2
The vibration transmissibility of 4b is lower than the CR rubber.

FIG. 5 shows the relationship between the vibration frequency of the rotor and Kd / Kst when the dynamic spring constant of the vibration damping members 24a and 24b is Kd and the static spring constant is Kst. The vibration isolators 24a and 24b have a smaller change in the spring constant with respect to the vibration frequency than the CR rubber, so that stable vibration isolation characteristics can be obtained regardless of the rotation speed of the rotor 6.

With the brushless motor configured as described above, the following operational effects can be obtained. (1) Since the center piece 3 is fixed to the motor holder 1 via the vibration isolating members 24a and 24b, vibration is generated in the rotor 6 with the rotation of the rotor 6, and the center piece 3 is generated based on the vibration. , The transmission of vibration from the center piece 3 to the motor holder 1 can be reliably blocked. (2) Since the center piece 3 close to the rotor 6 is fixed to the motor holder 1 via the vibration isolator 24a in the path where the vibration is transmitted from the rotor 6 that is the vibration source, the rotor 6 The number of components of the vibration transmission path to the fixed position can be reduced, and the vibration transmission path can be shortened. Therefore, the occurrence of resonance in the vibration transmission path can be prevented beforehand, and the occurrence of noise can be prevented. (3) Since the vibration isolating members 24a and 24b are formed of gel-like rubber or resin having excellent frequency characteristics of vibration transmission rate and spring constant, transmission of the vibration of the center piece 3 to the motor holder 1 is reliably prevented. be able to. (4) By fitting the locking groove 25 of the vibration isolator 24a into the mounting hole 26a of the motor holder 1, the boss portion 22 of the centerpiece 3 is oriented radially with respect to the motor holder 1, that is, in the horizontal direction in FIG. Can be reliably positioned. Also, the vibration isolators 24a and 24b are attached to the centerpiece 3
By compressing the boss portion 22 of the center piece 3 with respect to the motor holder 1, it is possible to reliably position the boss portion 22 in the axial direction thereof, that is, in the vertical direction shown in FIG. (5) Vibration transmission to the motor holder 1 can be reliably prevented only by the vibration isolators 24a and 24b interposed between the center piece 3 and the motor holder 1, so that the number of man-hours for assembling is increased. In addition, an increase in the number of parts can be prevented.

The above embodiment can be modified as follows. -Although the said vibration-proof material 24a, 24b was integrally molded with the gel-like rubber, it is possible to laminate and use the O-ring molded with the gel-like rubber and the annular plate-like vibration-proof material in a sandwich form. The same operation and effect as those of the vibration dampers 24a and 24b can be obtained. (Second Embodiment) FIG. 6 shows a second embodiment. This embodiment shows another embodiment of a fixed portion between the center piece 3 and the motor holder 1.

Centerpiece mounting hole 2 of motor holder 1
6a is a vibration isolator 2 made of a gel-like rubber or resin material.
9 are integrally formed. After shaping the synthetic resin motor holder 1 with a molding machine, the vibration isolator 29 is replaced with a core for molding the vibration isolator, and the mounting hole 26a is formed.
It is formed by integrally molding a gel-like rubber or resin material at the portion.

The boss portion 22 of the center piece 3 is inserted into the mounting hole 26a, and a screw 28 passing through the mounting plate 27 is screwed into the boss portion 22 so that the vibration isolator 2
9 is the fixing plate 21 and the mounting plate 27 of the center piece 3
Compressed between In this state, the boss 22 is positioned vertically and horizontally with respect to the mounting hole 26a of the motor holder 1.

With the brushless motor thus configured, the same operation and effect as those of the first embodiment (1) to (4) can be obtained, and further, the following operation and effect can be obtained. it can. (1) The work of assembling the vibration isolator 29 to the motor holder 1 becomes unnecessary, and the number of assembling steps can be reduced. (2) Since the motor holder 1 and the vibration isolator 29 are formed in the same mold, the mounting accuracy of the vibration isolator 29 to the motor holder 1 can be improved. (3) Since the positional accuracy of the vibration isolator 29 with respect to the motor holder 1 can be improved, the mounting accuracy of the center piece 3 fixed to the motor holder 1 via the vibration isolator 29 can be improved. (4) The positional accuracy between the sensor magnet 15 attached to the output shaft 9 of the rotor 6 and the Hall element attached to the circuit board 12 can be improved. (Third Embodiment) FIG. 7 shows a third embodiment. This embodiment is different from the first embodiment in that
The connection structure between the yoke 7 of the rotor 6 and the output shaft 9 is changed so that the vibration of the yoke 7 is not transmitted to the output shaft 9.

The output shaft 9 is press-fitted and fixed to the first and second connecting collars 31, 32, and an anti-vibration member 33 is disposed between the two collars 31, 32. The vibration isolator 33 is fitted in a mounting hole 34 formed in the center of the yoke 7.

Since the yoke 7 and the output shaft 9 need to rotate integrally, the space between the yoke 7 and the vibration isolator 34 and between the vibration isolator 34 and the first and second connecting collars 31 and 32 are formed. A detent means is required between them. The first and second connecting collars 31 and 32 including the detent means, the vibration isolator 33
8 and 9 show a specific configuration of the yoke 7.

The first and second connecting collars 31, 32 are
A burring portion 35 is formed at the center of the metal disk, and the output shaft 9 is press-fitted and fixed to the burring portion 35.
Four projections 36a are formed at equal intervals on the lower surface of the first connection collar 31, and four projections 36b are also formed at equal intervals on the upper surface of the second connection collar 32.

The vibration isolator 33 is formed of a normal synthetic rubber material or a gel-like rubber material into a disk shape having the same diameter as the first and second connection collars 31 and 32. A through hole 37 is formed to allow the burring portion 35 of the second connection collar 32 to be inserted. In addition, vibration insulator 3
3 is formed to be slightly thicker than the height of the burring portion 35 of the second connection collar 32.

On the upper and lower surfaces of the vibration isolator 33, recesses 38 for engaging with the protrusions 36a and 36b are formed at regular intervals. A reduced diameter portion 39 for fitting the mounting hole 34 of the yoke 7 is formed on the entire side surface of the vibration isolator 33. Four projections 40 are formed at equal intervals on the peripheral surface of the reduced diameter portion 39.

The mounting hole 34 of the yoke 7 is formed to have a diameter substantially equal to the diameter of the reduced diameter portion 39 of the vibration isolator 33, and the periphery thereof is provided with recesses 41 engaging with the projections 40 at regular intervals.
It is formed in some places.

The connecting collars 31, 3 formed in this way
2. To attach the yoke 7 to the output shaft 9 using the vibration isolator 33, press the output shaft 9 into the first connection collar 31 and press the output shaft 9 into the projection 36a on the lower surface of the first connection collar 31. Anti-vibration material 3
The third recess 38 is engaged.

Next, the reduced diameter portion 39 of the vibration isolator 33 is fitted into the mounting hole 34 of the yoke 7, and the projection 40 is engaged with the concave portion 41. Then, the second connection collar 32 is press-fitted into the output shaft 9 and the tip of the burring portion 35 is connected to the first connection collar 3.
Contact 1 At this time, the protrusion 36 b of the second connection collar 32 is engaged with the recess 38 of the vibration isolator 33. By such a procedure, the output shaft 9 is fixed to the yoke 7.

With the brushless motor configured as described above, the following operational effects can be obtained. (1) Since the vibration isolator 33 is interposed between the yoke 7 and the output shaft 9, transmission of vibration from the yoke 7, which is a vibration source, to the output shaft 9 can be prevented. Therefore, the resonance of each member constituting the motor can be reliably prevented, and the noise can be reduced. (2) Since detent means are formed between the yoke 7 and the vibration isolator 33 and between the vibration isolator 33 and the connecting collars 31 and 32, the idle rotation between the yoke 7 and the output shaft 9 is ensured. Can be prevented. (3) The vibration damping effect can be further improved by using a gel-like rubber or resin material as the vibration isolator 33.

Another example of the connection structure between the yoke 7 and the output shaft 9 as described above will be described below. FIG. 10 shows a first alternative example. In this alternative example, the first connecting collar 31 and the second connecting collar 32 are pressed into the output shaft 9 so that the burring portions 35 thereof abut each other, and the vibration isolating material 33 is provided between the collars 31 and 32. Is interposed. Further, between the yoke 7 and the vibration-proof material 33 and between the vibration-proof material 33 and both the collars 31 and 32, the same detent means as in the above embodiment are formed. With such a configuration, it is possible to obtain the same functions and effects as those of the above embodiment. -Second alternative example Fig. 11 shows a second alternative example. In this alternative example, the first connection collar 31a is formed in a flat plate shape, and is fixed to the output shaft 9 with a toothed washer 42. With such a configuration, it is possible to obtain the same functions and effects as those of the above embodiment. -Third alternative example Figs. 12 and 13 show a third alternative example. The first connection collar 31b is formed in a flat plate shape, and a through hole 43 for inserting the burring portion 35 of the second connection collar 32b is formed in the center portion. A screw 44 is provided around the through hole 43. Four through holes 45 for insertion are formed at equal intervals.

In the second connection collar 32b, four burring portions 46 are formed around the center burring portion 35 at equal intervals with the through holes 45, and female threads are formed on the inner peripheral surface of the burring portion 46. It is engraved.

The first and second connecting collars 31b, 32b
The vibration isolator supported between them is formed in a two-layer structure from the first vibration isolator 33a and the second vibration isolator 33b, and has a burring portion of the second connection collar 32b at the center thereof. Through holes 47 and 48 for inserting the 35 are formed,
Through holes 49 and 50 into which the burring portion 46 can be inserted.
Are respectively formed. Annular ribs 51a and 51b are formed around the through holes 48 and 50 of the second vibration isolator 33b.

The mounting hole 34 of the yoke 7 has a diameter capable of fitting the rib 51a of the second vibration isolator 33b.
A fitting hole 52, into which the rib 51b can be fitted, is formed around the mounting hole.

In order to assemble the respective members configured as described above, the output shaft 9 is press-fitted into the second connecting collar 32b, and the second vibration-proof material is inserted into the burring portions 35 and 46 of the second connecting collar 32b. The through holes 48 and 50 of 33b are fitted.

Next, the mounting hole 34 and the fitting hole 52 of the yoke 7 are fitted to the ribs 51a, 51b of the second connecting collar 32b, and the through holes 47, 49 of the first vibration isolator 33a are further fitted to the second holes. Is fitted to the burring portions 35 and 46 of the connecting collar 32b.

Then, the first connecting collar 31b is placed on the first vibration isolator 33a, and the burring portion 4 is inserted through the through hole 45.
When the screw 44 is screwed into the screw hole in 6, and the first and second connecting collars 31b and 32b are tightened together, the yoke 7 and the output shaft 9 are fixed integrally.

The thus configured yoke 7 and output shaft 9
In the connection structure of the first embodiment, the vibration isolating members 33a and 33b are interposed between the yoke 7 and the output shaft 9, so that the same operation and effect as in the above embodiment can be obtained. In addition, the screw 44 screwed into the screw hole in the burring portion 46 can reliably prevent the yoke 7 from idling between the first and second connection collars 31b, 32b. -Fourth alternative example Figs. 14 and 15 show a fourth alternative example. Another example of this is
Instead of the detent means comprising the burring portion 46 and the screw 44 of the third alternative example, a detent piece 53 is vertically suspended from the second connecting collar 32c.

That is, the detent piece 53 is formed in the second connecting collar 32c, and the detent piece 53 is inserted into the positioning hole 54 formed in the first and second vibration insulators 33a and 33b. Have been. The output shaft 9 of the first and second connection collars 31c and 32c is press-fitted and fixed to the burring portion 35 thereof. Then, the first and second vibration isolator 33
a and 33b are first and second connecting collars 31c and 32c.
It is sandwiched between.

With this configuration, the same operation and effect as those of the third alternative example can be obtained. Further, since the detent piece 53 can be easily formed by bending a part of the second connection collar 32c, the detent piece 53 is more easily formed than the detent means including the burring portion 46 and the screw 44 of the third alternative example. In addition, the number of man-hours and the number of parts during manufacturing can be reduced, and the cost can be reduced. -Fifth alternative example Figs. 16 and 17 show a fifth alternative example. Another example of this is
Rotation stopper pieces 55a and 55b projecting upward and downward are formed in the mounting hole 34 of the yoke 7.

That is, on the periphery of the mounting hole 34 of the yoke 7, a detent piece 55a projecting upward and a detent piece 55b projecting downward are formed at equal intervals. Then, the detent piece 55a is inserted into the positioning hole 56a formed in the first vibration isolator 33a, and the detent piece 55b is inserted into the positioning hole 56b formed in the second antivibration material 33b. I have.

The rib 57a formed on the upper surface of the first vibration isolator 33a is fitted into the fitting hole 58a formed in the first connecting collar 31d, and the lower surface of the second vibration isolator 33b is formed. Is fitted in a fitting hole 58b formed in the second connection collar 32d.

The first and second connecting collars 31d, 32d
The output shaft 9 is press-fitted and fixed to the burring portion 35. And the 1st and 2nd vibration-proof materials 33a and 33b are clamped between the 1st and 2nd connection collars 31d and 32d.

With this configuration, the same operation and effect as those of the fourth alternative example can be obtained. Further, the detent piece 53 can be easily formed by bending a part of the yoke 7, so that the burring portion 4 of the third alternative example is formed.
Compared with the detent means including the screw 6 and the screw 44, the number of steps and the number of parts during manufacturing can be reduced, and the cost can be reduced. -Sixth alternative example Fig. 18 shows a sixth alternative example. This alternative example prevents transmission of vibration of the yoke 7 to the fan 11. The output shaft 9 is rotatably fitted to the yoke 7, and the fan 11 is loosely fitted to the end of the output shaft 9 only by the E-ring 59 so that it cannot be pulled out.

A vibration isolator 60 is disposed between the upper surface of the yoke 7 and the fan 11. This vibration isolator 60
A convex portion 61 which is formed in a flat and annular shape and protrudes downward from the lower surface thereof is fitted into a through hole 62 formed on the upper surface of the yoke 7.

A connecting hole 63 is formed at the center of the projection 61, and a connecting shaft 64 projecting from the fan 11 is fitted into the connecting hole 63. Therefore, when the yoke 7 is rotated, the rotation of the yoke 7 is transmitted to the fan 11 via the convex portion 61 and the connection shaft 64, so that the fan 11 is rotated integrally with the yoke 7.

In the brushless motor configured as described above, the fan 11 is loosely fitted to the output shaft 9 only so as not to be able to be pulled out, and the vibration isolator 60 is interposed between the yoke 7 and the fan 11. Therefore, transmission of vibration from the yoke 7 to the fan 11 is prevented, and generation of noise due to vibration of the fan 11 can be prevented. (Fourth Embodiment) FIG. 19 shows a fourth embodiment. In this embodiment, the yoke 7 itself is formed as a vibration damping structure by forming the yoke 7 from a damping steel plate.
That is, the yoke 7 is formed of a damping steel plate in which a viscoelastic resin 66 is sandwiched between two steel plates 65a and 65b having a thickness of 0.2 to 1.6 mm.

When the rotor 6 is constituted by using the yoke 7 constructed as described above, the vibration of the rotor 6 itself can be suppressed during the operation of the brushless motor.
Therefore, other components of this motor or the fan 11
Vibration can be suppressed and noise can be prevented from occurring.

The technical ideas other than the claims described in the above embodiment and other examples are described below together with their effects. (1) In claim 8, the detent means comprises a projection and a recess provided between the yoke and the vibration isolator, and a projection and a recess formed between the vibration isolator and the collar. did. The detent means can be easily formed. (2) In claim 8, the detent means comprises a screw penetrating the collar, the vibration isolator, and the yoke. The idling between the yoke and the output shaft can be reliably prevented. (3) In claim 8, the detent means comprises a detent piece protruding from the collar and penetrating the vibration isolator and the yoke. The detent means can be easily formed, and the idling between the yoke and the output shaft can be reliably prevented. (4) In claim 8, the detent means comprises a detent piece protruding from the yoke and penetrating the vibration isolator and the collar. The detent means can be easily formed, and the idling between the yoke and the output shaft can be reliably prevented.

[0074]

As described in detail above, the present invention can provide a brushless motor capable of reliably preventing the generation of noise due to the rotation of the rotor.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment.

FIG. 2 is a perspective view showing a vibration isolator according to the first embodiment.

FIG. 3 is a characteristic diagram showing a vibration transmission characteristic of a vibration isolator.

FIG. 4 is a characteristic diagram showing a vibration transmission characteristic of the vibration isolator.

FIG. 5 is a characteristic diagram showing a vibration transmission characteristic of the vibration isolator.

FIG. 6 is a cross-sectional view showing a second embodiment.

FIG. 7 is a cross-sectional view showing a third embodiment.

FIG. 8 is a sectional view showing a main part of the third embodiment.

FIG. 9 is an exploded perspective view showing a third embodiment.

FIG. 10 is a sectional view showing a first alternative example of the third embodiment.

FIG. 11 is a sectional view showing a second modification of the third embodiment.

FIG. 12 is a sectional view showing a third modification of the third embodiment;

FIG. 13 is an exploded perspective view showing a third alternative example of the third embodiment.

FIG. 14 is a sectional view showing a fourth alternative example of the third embodiment.

FIG. 15 is an exploded perspective view showing a fourth alternative example of the third embodiment.

FIG. 16 is a sectional view showing a fifth modification of the third embodiment;

FIG. 17 is an exploded perspective view showing a fifth alternative example of the third embodiment.

FIG. 18 is a sectional view showing a sixth modification of the third embodiment.

FIG. 19 is a sectional view showing a fourth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Motor holder, 2 ... Stator, 6 ... Rotor, 7 ... Yoke, 9 ... Output shaft, 11 ... Fan, 21 ... Fixed plate, 22
... Boss parts, 24a, 24b, 33, 60 ... Vibration-proof material.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mineo Yamaguchi 390 Umeda, Kosai City, Shizuoka Prefecture Asmo Co., Ltd.

Claims (10)

[Claims] 1. A stator (2) is fixed to a motor holder (1), a rotor (6) is rotatably supported on the stator (2), and an exciting current is supplied to the stator (2). In a brushless motor for rotating a rotor (6), a fixed plate (21) is formed at one end of a center piece (3) constituting the stator (2), and a boss (22) is formed on the fixed plate (21). A brushless motor, wherein the boss portion (22) is formed and fixed to the motor holder (1) via a vibration isolator (24a). 2. The brushless motor according to claim 1, wherein said vibration isolator is formed of a gel-like rubber or resin material. 3. A stator (2) is fixed to a motor holder (1), a rotor (6) is rotatably supported on the stator (2), and an exciting current is supplied to the stator (2). In a brushless motor that rotationally drives a rotor (6), a center piece (3) constituting the stator (2) is provided.
Is made of a rubber-like rubber or resin material (24)
a, a brushless motor fixed to the motor holder (1) via a, 24b). 4. The vibration-proof material (24a) is formed in an annular shape so that the boss (22) can be fitted therein, and a locking groove is formed at a central portion in the axial direction of the outer peripheral surface of the vibration-proof material (24a). (25)
The motor holder (1) is formed in the locking groove (25).
The centerpiece (3) is fixed to the motor holder (1) by fitting the mounting hole (26a) of the motor and the vibration-proof material (24a) between the centerpiece (3) and the mounting plate (27). 4. The vibration damping member (24a) is positioned in a radial direction and an axial direction with respect to the vibration isolating member (24a).
A brushless motor according to any one of the above. 5. The vibration damping material (24a) is formed by sandwiching an O-ring formed of gel rubber or resin between a pair of annular plate-shaped vibration damping materials. 3
A brushless motor according to any one of the above. 6. The motor vibration isolator according to claim 1, wherein said vibration isolator is formed integrally with said motor holder.
4. The brushless motor according to any one of claims 1 to 3. 7. A stator (2) is fixed to a motor holder (1), a rotor (6) is rotatably supported on the stator (2), and an exciting current is supplied to the stator (2). In a brushless motor for rotatingly driving a rotor (6), a vibration isolator (33) is interposed between a yoke (7) constituting the rotor (6) and an output shaft (9) of the rotor (6). A brushless motor. 8. The vibration isolator (33) is attached to collars (31, 32) fixed to the output shaft (9), and the yoke (7) is attached to the vibration isolator (33). The anti-rotation means is provided between the vibration isolator (33) and the collars (31, 32) and between the vibration isolator (33) and the yoke (7). The brushless motor according to claim 7, wherein the yoke (7) and the yoke (7) cannot rotate relative to each other. 9. A stator (2) is fixed to a motor holder (1), a rotor (6) is rotatably supported on the stator (2), and an exciting current is supplied to the stator (2). A brushless motor for rotating a rotor (6), comprising: a yoke (7) constituting the rotor (6); and a fan (11) rotatably supported on an output shaft (9) of the rotor (6). A brushless motor, wherein the brushless motor is connected via a vibration isolator (60) so as to be relatively non-rotatable. 10. A stator (2) on a motor holder (1).
, A rotor (6) is rotatably supported by the stator (2), and an excitation current is supplied to the stator (2) to rotate the rotor (6). A brushless motor characterized in that the yoke (7) constituting 6) is formed of a damping steel plate.