JPH09322461A - Holding construction for electric rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise by providing a projected portion on an inner periphery of a holder, which has a point contact with a knot of the vibration mode of a cylindrical yoke, in an electric rotating machine equipped with a holder for holding the outer peripheral portion of a housing for fixing a cylindrical yoke arranged for a bearing at an opening end of the yoke of the rotating machine. SOLUTION: An electric rotating machine portion 1 comprises a cylindrical yoke 2, a front yoke 3, a rear yoke 4, a rotor 5 and a holder 8 for the electric rotating machine. A stator is formed by arranging a magnet 9 inside the cylindrical yoke 2. An opening is provided at each end of the cylindrical yoke 2, the front yoke 3 is provided at one end thereby forming a bearing housing 3a for the bearing portion 6 and is coupled to the cylindrical yoke 2. The stator 5 is held by bearings 6 and 7 in a freely rotatable manner. On the inner diameter of the holder 8 for the rotating machine, at least two projected portions 12 in contact with the outer periphery of the cylindrical yoke 2 at the positions where the vibration of the cylindrical yoke 2 are small for making the contact area smaller between the cylindrical yoke 2 and the electric rotating machine holder 8. By doing this, peak noise around 2,000Hz can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine holding structure, and more particularly to a rotary electric machine holding structure suitable for a fan motor used in a vehicle air conditioner.

[0002]

2. Description of the Related Art In a rotary electric machine used for a vehicle, for example, a fan motor, noise caused by vibration of the motor is a cause of noise in the passenger compartment.

Generally, in a conventional rotary electric machine, when the rotary electric machine is held, a cylindrical yoke is press-fitted and held in a resin holder, and the vibration of the cylindrical yoke directly occurs.
It was transmitted to the resin holder and made noise.

That is, the conventional holding structure for a rotating electric machine will be described with reference to FIG. 9. In FIG. 9, reference numeral 42 is a cylindrical yoke as a stator, and substantially rectangular yokes are provided at both axial ends of the cylindrical yoke 42. It has a front housing 43 and a rear housing 44 that constitute it. Reference numeral 45 represents a rotor, which includes a front housing 43 and a rear housing 44.
It is rotatably supported by bearings 46 and 47 held by.

Reference numeral 48 is a resin holder having a cylindrical portion 49 for holding the motor portion 41 and a bottom portion 50. The motor portion 41 is configured such that the yoke 42 and the cylinder portion 49 are in contact with each other, and the rear housing 44 and the bottom portion 50 are in contact with each other.

[0006]

In the rotary electric machine having such a structure, since the motor portion and the resin holder are integrated, the vibration of the yoke 42 is directly transmitted to the resin holder, which causes noise. Was there. That is, the resin holder 48 not only serves as a holder for the motor section, but also has the cylindrical section 49 and the bottom section 50 for holding the motor section 41, and the contact area between the motor section 41 and the resin holder 48 is large and they are integrated. Therefore, the vibration of the yoke 42 is directly transmitted to the resin holder 48. Further, the vibration transmitted to the resin holder 48 is transmitted to the flange portion 51 and causes noise.

For this reason, the rotating electric machine is made to have a floating holding structure using a vibration-proof rubber, so that the vibration and noise of the rotating electric machine are reduced.

However, the floating holding structure using the anti-vibration rubber has the disadvantage of increasing the number of members and the number of assembling steps.

The inventor of the present invention pays attention to the fact that the vibration generated by the motor is directly transmitted to the housing and the motor holder which is in surface contact with the housing, and the flange of the motor holder vibrates to increase the noise. However, in a fan motor, for example, most of the noise is air noise generated by rotating the fan,
It was found that a metallic sound around 2000 Hz was added to this sound and it was recognized as an unpleasant sound.

Therefore, when the vibration behavior mode of the motor including around 2000 Hz was analyzed, it was found that there was a pattern peculiar to the vibration behavior mode for each vibration Hz value. In particular, as shown in the examples described below,
At around 2000 Hz, it was found that the vibration behavior mode had one pattern (see FIG. 5) and at 1500 Hz had two patterns (see FIGS. 6 and 7), and a portion having a small vibration amplitude that was a node of vibration was identified. It was

The present invention has been made on the basis of such knowledge, and an object of the present invention is to reduce noise recognized as uncomfortable noise as noise in combination with other sounds. The purpose is to prevent the propagation of vibration and to reduce noise, and particularly to reduce the noise around 2000 Hz.

[0012]

In a holding structure for a rotary electric machine according to claim 1 of the present application, a cylindrical yoke and a yoke provided at an opening end of the cylindrical yoke and having a bearing portion are fixed to each other. A rotary electric machine that includes a housing and a rotary electric machine holder that holds an outer peripheral portion of the housing, and a protrusion is provided on an inner circumference of the rotary electric machine holder so as to make point contact with a node of a vibration mode of the cylindrical yoke. It is characterized by that.

According to a second aspect of the present invention, there is provided a holding structure for a rotary electric machine, wherein a cylindrical yoke and a substantially rectangular yoke arranged at an open end of the cylindrical yoke and having a bearing portion are fixed to a housing. A rotary electric machine holder for holding an outer peripheral portion of the housing, wherein the rotary electric machine holder is in point contact with a position of a cylindrical yoke corresponding to a portion substantially 45 degrees from a longitudinal center of a substantially rectangular yoke. The projections are provided at least at two or more points on the inner circumference of the.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The holding structure for a rotary electric machine according to the present invention is
A roughly rectangular yoke is arranged at the open end of the cylindrical yoke, a bearing portion is formed on the roughly rectangular yoke, and the cylindrical yoke and the roughly rectangular yoke are fixed to form a housing. The outer peripheral portion of is intended for the rotary electric machine held by the rotary electric machine holder.

As a center line in the longitudinal direction of the substantially rectangular yoke, a protrusion is formed on the inner periphery of the rotary electric machine holder so as to make point contact with the outer peripheral side of the position of the cylindrical yoke corresponding to the portions on both sides from the center line. Is formed. This projection is formed at least at two or more points, and preferably three or more projections can stably maintain the gap between the rotary electric machine holder and the cylindrical yoke.

As described above, as shown in FIGS. 5 and 7, the position of the cylindrical yoke corresponding to the center line in the longitudinal direction of the substantially rectangular yoke, which is approximately 45 degrees on both sides from this center line, has very little vibration. The vibration of the rotating electric machine does not propagate to the rotating electric machine holder because the housing is assembled to the rotating electric machine holder by making point contact with this portion.
In other words, the cylindrical yoke and the rotary electric machine holder are not in contact with each other at the portions other than the protrusions, and are in contact with each other from the conventional surface contact to a point contact at a place where there is little vibration, and the propagation of vibration can be extremely reduced.

In particular, the position of the cylindrical yoke, which corresponds to approximately 45 degrees on both sides of the center line in the longitudinal direction of the roughly rectangular yoke, is the node of vibration at 2000 Hz shown in FIG. 1500Hz as shown
Since it is a part of a node of the vibration mode, the propagation of these vibrations can be prevented. Therefore, as shown in FIG. 3, noise reduction of approximately 3 dB could be obtained at 2000 Hz and 1500 Hz.

[0018]

An embodiment of the present invention will be described below with reference to the drawings. The members, arrangements, and the like described below do not limit the present invention, and can be variously modified within the scope of the present invention.

1 to 3 show an embodiment of a holding structure for a rotary electric machine according to the present invention. FIG. 1 is a sectional explanatory view and a partially enlarged view, and FIG. 2 is a part seen from a rear end rectangular yoke. FIG. 3 is a perspective view, and FIG. 3 is a graph showing a noise condition.

As shown in FIG. 1, reference numeral 1 is a rotary electric machine section, and the rotary electric machine section 1 of the present embodiment includes a cylindrical yoke 2, a front yoke 3 and a rear yoke 4 which are substantially rectangular yokes.
The rotor 5, and the rotary electric machine holder 8 are the main constituent elements. In the cylindrical yoke 2 of this example, a magnet 9 is arranged at a predetermined position on the inner side and constitutes a stator.

Both ends of the cylindrical yoke 2 are open, and a front yoke 3 as a substantially rectangular yoke is provided on one end side. Front yoke 3 of this example
A bearing house 3a, in which the bearing portion 6 is disposed, is formed therein, and is connected to the cylindrical yoke 2.

The rotor 5 of this embodiment is rotatably supported by bearings 6 and 7 held by the front yoke 3 and the rear yoke 4.

The rotary electric machine holder 8 of this example is made of resin and has an inner diameter larger than the outer diameter of the cylindrical yoke 2 so that the end side is open and the surface of the cylindrical yoke 2 does not come into surface contact. It is set.

At one end of the rotary electric machine holder 8,
Positioning bending part 10 for positioning the rotating electrical machine part 1
Are formed. A flange portion 11 is provided in the outer diameter direction of the rotary electric machine holder 8.
A plurality of mounting holes are provided on the outer periphery of the. Further, on the inner diameter of the rotary electric machine holder 8, at least two or more protrusions 12 that come into contact with the outer circumference of the cylindrical yoke 2 are provided at positions where the vibration of the cylindrical yoke 2 is small.

The formation position of the protrusion 12 is the center line in the longitudinal direction of the front yoke 3 and the rear yoke 4 which are substantially rectangular yokes, and the outer peripheral side of the position of the cylindrical yoke 2 corresponding to the portions approximately 45 degrees on both sides from this center line. Further, a protrusion is formed so as to make point contact. This position is a part which becomes a node of the vibration mode at a part of 1500 Hz and 2000 Hz, and is a part where the vibration is the smallest in this vibration region.

Although the protrusions are formed at four places in this example, it is sufficient that they are formed at least at two or more points. Preferably, when the protrusions are formed at two or three positions which are not adjacent to each other, the rotary electric machine holder 8 and A gap with the cylindrical yoke 2 can be stably maintained.

With the configuration as described above, the rotary electric machine part 1 includes the position on the cylindrical yoke 2 at which vibration is small at least two points, the protrusion 12 on the inner diameter of the rotary electric machine holder 8, and the rear yoke 4. The contact area between the cylindrical yoke 2 and the rotary electric machine holder 8 can be reduced by being held by the positioning bending portion 10, and the vibration of the cylindrical yoke 2 can be prevented from being directly transmitted to the rotary electric machine holder 8. Therefore, the flange portion 11 does not vibrate, and the generation of noise can be prevented. That is, as shown in FIG.
It was possible to obtain a noise reduction of dB and also to reduce the peak noise around 2000 Hz.

In the embodiment described above, the cylindrical yoke 2 and the rotary electric machine holder 8 are the projections 1 on the inner circumference of the rotary electric machine holder 8.
2, but as another embodiment, as shown in FIG.
It is also possible to have a structure in which only the rear yoke 4 and the positioning bent portion 10 are supported by the protrusions, and the cylindrical yoke 2 and the rotary electric machine holder 8 do not abut.

The present invention is characterized in that the cylindrical yoke and the rotary electric machine holder are kept in non-contact with each other as much as possible, and, of course, does not relate to the technique of mounting the mounting member on the outer periphery of the rotary electric machine holder. In addition, as a center line in the longitudinal direction of the substantially rectangular yoke, approximately 4 on both sides from this center line
The position of the cylindrical yoke corresponding to the 5 ° portion is a portion that becomes a node with extremely little vibration, and the housing and the rotating electric machine holder are brought into contact with each other by point contact to assemble only this portion, such as screws and screws. It is not assembled by a fixing tool. Therefore, it is extremely suitable for automatic assembly.

[0030]

According to the present invention, the cylindrical yoke and the rotary electric machine holder are not in contact with each other at a portion other than the protrusion, and the surface contact is not the conventional one, and the point contact portion is a place where vibration is small. Therefore, the propagation of vibration can be extremely reduced.

In particular, the position of the cylindrical yoke, which corresponds to approximately 45 degrees on both sides from the center line as the center line in the longitudinal direction of the roughly rectangular yoke, is a node of vibration at 2000 Hz and a part of the vibration mode at 1500 Hz. Therefore, it is possible to prevent the propagation of these vibrations, which cause an unpleasant sound as a metallic sound, along with other noises. As described above, in the present invention, noise reduction of approximately 3 dB can be obtained at 2000 Hz and 1500 Hz, and a gap is provided between the cylindrical yoke and the resin holder to prevent vibration propagation and reduce noise. .

[Brief description of drawings]

FIG. 1 is a sectional explanatory view and a partially enlarged view showing an embodiment of a holding structure for a rotary electric machine according to the present invention.

FIG. 2 is a perspective view showing a part of an embodiment of a holding structure for a rotary electric machine according to the present invention.

FIG. 3 is a graph diagram in which a noise state of a holding structure for a rotary electric machine that is an example of the present invention is measured.

FIG. 4 is a graph showing a noise state of a holding structure for a rotary electric machine according to a conventional example.

FIG. 5 is an explanatory diagram of a vibration mode at 2000 Hz of the rotating electric machine.

FIG. 6 is an explanatory diagram of a vibration mode of the rotary electric machine at 1500 Hz.

FIG. 7 is an explanatory diagram of a vibration mode of the rotary electric machine at 1500 Hz.

FIG. 8 is a partially enlarged view showing another embodiment of the holding structure for a rotary electric machine of the present invention.

9A and 9B are a sectional explanatory view and a partially enlarged view showing an example of a holding structure for a rotary electric machine according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotating electric machine part 2 cylindrical yoke 3 roughly rectangular yoke (front yoke) 3a bearing house 4 roughly rectangular yoke (rear yoke) 5 rotor 6 bearing part 7 bearing part 8 rotating electric machine holder 9 magnet 10 positioning bending part 11 flange part 12 protrusion

Claims (2)

[Claims] 1. A housing to which a cylindrical yoke and a yoke having a bearing portion formed at the open end of the cylindrical yoke are fixed, and a rotary electric machine holder that holds an outer peripheral portion of the housing. The rotating electric machine holding structure according to claim 1, wherein a protrusion is provided on the inner circumference of the rotating electric machine holder so as to make point contact with a node of the vibration mode of the cylindrical yoke. 2. A housing in which a cylindrical yoke and a generally rectangular yoke having a bearing portion formed at the open end of the cylindrical yoke are fixed, and a rotating electric machine holding an outer peripheral portion of the housing. In a rotary electric machine including a holder, protrusions are provided at least at two or more points on the inner circumference of the rotary electric machine holder so as to make point contact with a position of a cylindrical yoke corresponding to a portion substantially 45 degrees from the longitudinal center of the substantially rectangular yoke. A holding structure for a rotating electric machine, characterized by being provided.