JPH0965604A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the tilting of a bearing caused by the eccentric movement of a rotor or vibrations or impacts from a load by providing a plurality of grooves at different positions in the axial direction on the inner peripheral surface of the bearing holding recessed section of at least either a front cover or a rear cover and supporting the bearing with O-rings respectively positioned in the grooves. SOLUTION: Two grooves 15a and 15b are provided on different positions in the axial direction on the inner peripheral surface of the bearing holding recessed section 13 of the front cover 5 of a rotary electric machine. Then O-rings 16a and 16b are respectively positioned in the grooves 15a and 15a to support a bearing 11 so as to prevent the tilting of the bearing 11 caused by the eccentric movement of a rotor or vibrations or impacts from a load. Therefore, the soundproofing effects of the O-rings 16a and 16b can be stabilized and improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine such as an electric motor, and more particularly to improvement of a soundproof bearing portion thereof.

[0002]

2. Description of the Related Art FIG. 6 shows the structure of a conventional rotary electric machine of this type. In this rotating electric machine, a rotor 2 is rotatably arranged in a stator 1. The stator 1 has a structure in which a permanent magnet 4 is supported on the inner circumference of a cylindrical stator yoke 3. Metallic front covers 5 on both sides of the stator 1.
And a rear cover 6 which are connected to both sides of the stator yoke 3 by connecting screws 7. The rotor 2 is composed of a rotor core 8 and a rotor winding 9 wound around the rotor core 8. The rotary shaft 10 that supports the rotor 2 is
The front cover 5 and the rear cover 6 are rotatably supported by metal bearings 11 and 12 respectively supported on the inner circumferences of the front cover 5 and the rear cover 6. These bearings 11 and 12 include a front cover 5 and a rear cover 6.
It is housed in the bearing holding recesses 13 and 14. As shown in FIG. 7, the groove 1 is formed on the inner circumference of the bearing holding recess 13 of the front cover 5.
5, an O-ring 16 is arranged in this groove 15,
The bearing 11 is supported by the O-ring 16. A slip ring 17 is supported on the rotary shaft 10 between the rear cover 6 and the rotor 2, and a brush 18 is supported on the stator 1 side and is in contact with the slip ring 17.

When the bearing 11 is supported by the O-ring 16 as shown in the figure, the O-ring 16 absorbs the propagation of sound from a load (not shown) attached to the rotary shaft 10, so that a soundproof effect can be obtained. ing.

[0004]

However, in such a conventional rotary electric machine, since the rotary shaft 10 is supported by one O-ring 16, it is attached to the eccentric movement of the rotor 2 or the rotary shaft 10. The bearing 11 collapses due to vibration or impact from a load (not shown), the bearing 11 and the bearing holding recess 13 of the front cover 5 come into contact with each other, and the O-ring 16 cannot provide sound insulation. There is a problem that the soundproof effect is lost because the sound is propagated to the front cover 5 through the contact portion between the front cover 11 and the front cover 5 and goes out.

FIG. 8 (A) shows the noise measurement result of the rotating electric machine when the sound is insulated by the O-ring 16.
The total noise level was 57.5 dB.

FIG. 8B shows the noise measurement result of the rotating electric machine when the O-ring 16 is not sound-insulated, and the total noise level was 62 dB.

An object of the present invention is to provide a rotating electric machine capable of preventing the bearing supported by the O-ring from falling.

[0008]

According to the present invention, a rotor is rotatably arranged in a stator, a front cover and a rear cover are provided on both sides of the stator, and a rotary shaft for supporting the rotor is provided. The object of the improvement is a rotating electric machine that is rotatably supported by bearings that are respectively supported on the inner circumferences of the front cover and the rear cover.

In the rotating electric machine according to the present invention, a plurality of grooves are provided at different positions in the axial direction on the inner circumference of the bearing holding recess of at least one of the front cover and the rear cover, and these grooves are respectively arranged in these grooves. The bearing is supported by the O-ring. When the bearing is thus supported by the plurality of O-rings arranged at different positions in the axial direction, it is possible to prevent the bearing from collapsing due to eccentric movement of the rotor or vibration or impact from a load. Therefore, the soundproof effect by the O-ring can be stabilized, and the soundproof effect can be improved.

In this case, the filling rate of the O-ring in the groove is 80%.
It is preferable to set the above.

When the filling rate of the O-ring with respect to the groove is increased in this way, the elastic force of the O-ring increases, and the bearing is hardly moved by the eccentric movement of the rotor or the vibration or impact from the load. It is possible to more effectively prevent the bearing from falling. Therefore, the soundproof effect by the O-ring can be further stabilized, and the soundproof effect can be further improved.

[0012]

1 to 4 show an example of an embodiment of a rotary electric machine according to the present invention.

In the rotating electric machine of this example, two grooves 15a and 15b are provided on the inner periphery of the bearing holding recess 13 of the front cover 5 at axially different positions as shown in FIG. . Each of the grooves 15a and 15b has a groove width dimension G and a groove outer dimension dimension D. These grooves 15
The O-ring 16 having a diameter W of the wall portion is provided in a and 15b.
a and 16b are respectively arranged and these O-rings 16
The bearing 11 is supported by a and 16b.

When the bearing 11 is supported by the two O-rings 16a and 16b arranged at different positions in the axial direction as described above, the bearing 11 falls due to eccentric movement of the rotor 2 or vibration or impact from a load. Can be prevented. Therefore, the soundproof effect of the O-rings 16a and 16b can be maintained.

In this case, the filling rate of the O-rings 16a and 16b in the grooves 15a and 15b is preferably set to 80% or more.

When the filling rate S of the O-rings 16a and 16b with respect to the grooves 15a and 15b is increased in this way, the filling rate S is obtained by the equation (1),

[Equation 1] Here, W: O-ring thickness dimension G: Groove width dimension D: Groove outer dimension d: Bearing outer dimension The larger the filling rate S, the larger the elastic force of the O-rings 16a and 16b, and the rotor. The bearing is hardly moved by the eccentric movement of 2 or the vibration or impact from the load, and it is possible to more effectively prevent the bearing 11 from falling.

It is preferable to determine the groove width dimension G and the groove outer dimension D so that the filling rate S is 80% or more. By doing so, the elastic force of the O-rings 16a, 16b becomes large, the bearing is hardly moved by the eccentric movement of the rotor 2 or the vibration or impact from the load, and the bearing 11 falls more effectively. Can be prevented.

FIG. 5A shows the noise measurement result of the rotating electric machine when the filling rate S of the O-rings 16a and 16b is 80% or more, and the total noise level was 51 dB.

FIG. 5B shows the noise measurement result of the rotating electric machine when the filling rate S of the O-rings 16a and 16b is smaller than 80%, and the total noise level was 55 dB.

Thus, the total noise level when the filling rate S of the O-rings 16a and 16b is 80% or more is compared with the total noise level when the filling rate S of the O-rings 16a and 16b is smaller than 80%. The noise value was reduced by 4 dB, and the noise was reduced by 6 dB or more as compared with the conventional soundproof bearing structure of the rotating electric machine shown in FIGS.

The O-rings 16a and 16b are provided only in the bearing holding recess 14 of the rear cover 6, or the bearing holding recess 13 of the front cover 5 and the bearing holding recess 14 of the rear cover 6.
It is also possible to provide both.

The number of O-rings is not limited to two, but two or more may be provided.

[0023]

In the rotary electric machine according to the present invention, a plurality of grooves are provided at different positions in the axial direction on the inner circumference of the bearing holding recess of at least one of the front cover and the rear cover, and these grooves are respectively arranged. Since the bearing is supported by the formed O-ring, it is possible to prevent the bearing from collapsing due to the eccentric movement of the rotor or the vibration or shock from the load. Therefore, according to the present invention, the soundproof effect by the O-ring can be stabilized and the soundproof effect can be improved.

In this case, the filling rate of the O-ring in the groove is 80%.
It is preferable to set the above.

When the filling rate of the O-ring with respect to the groove is increased as described above, the elastic force of the O-ring is increased, and the bearing is hardly moved by the eccentric movement of the rotor or the vibration or impact from the load. It is possible to more effectively prevent the bearing from falling. Further, the soundproof effect by the O-ring can be further stabilized, and the soundproof effect can be further improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of an embodiment of a rotary electric machine according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing the structure of a bearing holding recess in the front cover in this example.

FIG. 3A is a front view of an O-ring used in this example,
(B) is a cross-sectional view of the O-ring.

FIG. 4 is an enlarged cross-sectional view showing a structure of a bearing holding portion in the front cover in this example.

FIG. 5A is a characteristic diagram showing the noise measurement result of the rotating electric machine when the filling rate S of the O-ring is 80% or more, and FIG.
It is a characteristic view showing a noise measurement result of the rotary electric machine when the filling rate S of the ring is smaller than 80%.

FIG. 6 is a vertical sectional view of a conventional rotating electric machine.

7 is an enlarged cross-sectional view showing the structure of a bearing holding portion in the front cover shown in FIG.

FIG. 8A is a characteristic diagram showing a noise measurement result of a rotating electric machine when sound is insulated by an O ring, and FIG. 8B is a noise measurement result of a rotating electric machine when sound is not insulated by an O ring. It is a characteristic diagram showing.

[Explanation of symbols]

 1 Stator 2 Rotor 3 Stator Yoke 4 Permanent Magnet 5 Front Cover 6 Rear Cover 7 Connecting Screw 8 Rotor Core 9 Rotor Winding 10 Rotating Shaft 11, 12 Bearing 13, 14 Bearing Holding Recess 15, 15a, 15b Groove 16, 16a, 16b O-ring 17 Slip ring 18 Brush

Claims (2)

[Claims] 1. A rotor is rotatably arranged in a stator, and a front cover and a rear cover are provided on both sides of the stator, and a rotary shaft supporting the rotor is provided with the front cover and the rear cover. In a rotary electric machine rotatably supported by bearings respectively supported on the inner circumference of the cover, a plurality of axially different positions are provided in the inner circumference of at least one of the bearing holding recesses of the front cover and the rear cover. The groove is provided, and the bearing is supported by O-rings respectively arranged in the grooves. 2. The filling rate of the O-ring in the groove is 80%.
The rotary electric machine according to claim 1, wherein the rotary electric machine is set as described above.