JP3657697B2 - Compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hermetic compressor, and more particularly, to a hermetic compressor including an electric motor core that can reduce vibrations generated by gas discharged from a compressor.
[0002]
[Prior art]
FIG. 1 shows an outline of a hermetic compressor. As shown in FIG. 1, the hermetic compressor has a hermetic casing 1. The casing 1 has a discharge port 2 that sends out refrigerant toward a condenser (not shown), and a suction port 3 that receives refrigerant returned from the evaporator (not shown) through a suction cup 4. ing. A compression part 5 is accommodated in the lower part in the casing 1, and the compression part 5 compresses the refrigerant gas and sends it out toward the discharge port 2 provided in the upper part of the casing 1.
[0003]
An electric motor 6 for driving the compression unit 5 is provided between the compression unit 5 and the discharge port 2. The electric motor 6 includes an electric motor core (stator) 10 disposed on the outer peripheral side of the rotor 7 and windings 8 disposed on both upper and lower sides of the electric motor core 10. The refrigerant gas sent out from the compression unit 5 passes between the winding 8 and the motor iron core 10 and the rotor 7 and heads toward the discharge port 2.
[0004]
[Problems to be solved by the invention]
As described above, the electric motor 6 placed in the refrigerant gas discharge path from the compressor 5 vibrates when the winding 8 and the electric motor core 10 receive the pulsation of the refrigerant gas (see the arrow in FIG. 1). This vibration is transmitted to the compressor casing 1 through the electric motor core 10, and further transmitted to accessories such as the suction cup 4 and the terminal box cover 9 attached to the casing 1, causing vibration and noise. Yes.
[0005]
As a general method conventionally used for reducing the vibration and noise of the compressor, first, there is a method of providing a muffler in a discharge path from a refrigerant gas cylinder (not shown). However, when the muffler is designed with an emphasis on noise performance, there is a drawback that the compression loss increases and the performance of the compressor is reduced.
[0006]
As a second method, there is a method of shifting the natural frequency of the component so that the component of the compressor does not resonate due to vibration transmission. However, when emphasizing the natural frequency of the component parts, there is a problem that the design freedom of the compressor is reduced.
[0007]
Further, as a third technique, there is a technique in which a component is fixed with a rubber band or absorbed via a spring in order to absorb vibration, that is, a technique using a cushioning material. However, the provision of the cushioning material leads to an increase in the number of parts and consequently an increase in the manufacturing cost of the compressor.
[0008]
Thus, at present, no method has been found that can reduce the vibration and noise of the compressor at a low cost without degrading the performance of the compressor itself.
[0009]
The present invention has been made in view of the above, and provides a structure of an electric motor core that can reduce the vibration and noise of the compressor at a low cost without degrading the performance of the compressor itself. It aims at providing a compressor with little vibration and noise.
[0010]
[Means for Solving the Problems]
To achieve the above object, a first means, in a compressor having a compression section and an electric motor disposed within the casing, said motor core of the motor comprises a plurality of plates which are caulked stacked, a plurality of these Of the plates, at least a predetermined range of the plates is formed with a convex portion projecting in the thickness direction on each plate so that a gap is formed between the adjacent plates, and the interval between the adjacent plates is h 1. When the height of the caulking portion is h 2 and the thickness of the plate is t , the relation that h 1 , h 2 and t are 0.2t <h 1 <2t and t + h 1 <h 2 It is characterized by satisfying .
[0011]
According to the first means, since the gap is formed between the adjacent plates, the vibration damping performance of the motor core is improved. Further, assuming that the interval between adjacent plates is h 1 , the height of the caulking portion is h 2 , and the thickness of the plate is t, h 1 , h 2 and t are 0.2 t <h 1 By satisfying the relationship of <2t and t + h 1 <h 2 , an electric motor core having the best vibration damping performance can be obtained.
[0012]
The second means is characterized in that the convex portion is provided in the vicinity of the caulking portion.
[0013]
According to the second means, since the convex portion is provided in the vicinity of the caulking portion, when caulking is performed, the plates are kept in parallel and the interval between the plates is also kept constant.
[0016]
The third means is characterized in that the positions of the convex portions formed on the plates adjacent to each other are different.
[0017]
According to the third means , since the positions of the convex portions formed on the plates adjacent to each other are different, when the plates are stacked, the convex portions of one plate and the convex portions of the other plate among the adjacent plates. The positions of the recesses formed on the back surface of the plate coincide with each other so that the projections enter the recesses, so that the interval between adjacent plates does not become uneven.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show an embodiment of the present invention. In the following description of the present embodiment, the same parts as those in the prior art are denoted by the same reference numerals, and detailed description thereof is omitted.
[0019]
As shown in FIG. 3, a range of about 10 to 20 mm from the lower end of the motor core 10 is formed by alternately stacking plates 11A formed by punching steel plates and plates 11B having substantially the same shape as the plates 11A. It is formed by doing. The difference in shape between the plate 11A and the plate 11B will be described later.
[0020]
As shown in FIG. 2, the outer edge of the plate 11 </ b> A has four outer edges that have substantially the same outer diameter as the inner diameter of the casing 1 in which the motor core 10 is accommodated and that follow the shape of the circumference 12 centering on the center point 11 a. It consists of a circular arc part 12a and four linear parts 12b located between the circular arc parts 12a.
[0021]
As shown in FIGS. 2 and 3, a plurality of protrusions 13 arranged at predetermined intervals in the circumferential direction are formed on the inner peripheral side of the plate 11 </ b> A. Is located on a circumference having a diameter slightly larger than the outer diameter of the rotor 7.
[0022]
On the plate 11A, caulking protrusions 14 (caulking portions) are respectively formed at positions close to the four arc portions 12a on the outer edge. Each caulking projection 14 is arranged at a position obtained by dividing the circumference 12 into four equal parts.
[0023]
In addition, a pair of hemispherical convex portions 15 are formed in the vicinity of the caulking projection portion 14. The convex portions 15 are arranged at symmetrical positions with respect to the caulking projection portion 14 at a distance X from the caulking projection portion 14 in the circumferential direction. As shown in FIG. 3, the caulking protrusions 14 and the protrusions 15 protrude in the plate thickness direction of the plate 11A.
[0024]
The plate 11B adjacent to the plate 11A differs from the plate 11A only in the distance between the caulking protrusion 14 and the convex portion 15, and the shape and dimensions of the other parts are the same as those of the plate 11A. That is, as shown in FIG. 3, the distance between the caulking projection 14 and the projection 15 in the plate 11B is X ′ smaller than the distance X between the caulking projection 14 and the projection 15 in the plate 11A. Yes. That is, the positions of the convex portions of the adjacent plates do not coincide with each other, and accordingly, when the plates 11A and 11B are alternately laminated and crimped, the convex portions 15 of the plate 11A are convex of the adjacent plate 11B. It does not enter the inside of the recess formed on the back surface of the portion 15.
[0025]
Further, when the gap between the plates 11A and 11B determined by the depth of the convex portion 15 is h1, the height of the caulking projection 14 of the plates 11A and 11B is h2, and the thickness of the plates 11A and 11B is t. , H1, h2 and t satisfy the relationship of 0.2t <h1 <2t and t + h1 <h2. The above relationship is obtained experimentally, and by satisfying this relationship, the optimum vibration isolation performance can be obtained.
[0026]
Moreover, the part above the range which has the structure shown in FIG. 3 which forms the clearance gap between laminated steel plates among the motor cores 10, ie, the part above 10-20 mm from the lower end of a motor core, is shown in FIG. The plates 11C adjacent to each other are stacked so as to be in close contact with each other and have a known structure that is caulked by caulking protrusions 14. The plate 11C is different from the plates 11A and 11B in that the convex portion 15 is not formed, and the other is substantially the same as the shape of the plates 11A and 11B. The laminated structure in which a gap is formed between the plates 11A and 11B adjacent to each other is within a predetermined range from the side where the refrigerant gas from the compressor 5 directly collides in the electric motor core 10 (this embodiment). In the embodiment, it is preferably provided in a range of 10 to 20 mm from the lower end. Moreover, the laminated structure in which a gap is formed between adjacent plates may be provided in another range of the motor core 10, for example, near the center, or the entire motor core 10 may have the above structure.
[0027]
In the above embodiment, the convex portions formed per plate 11A (11B) are four to eight, but the present invention is not limited to this, and the number of convex portions may be further increased. .
[0028]
Next, the operation of the present embodiment having the above configuration will be described.
[0029]
First, the operation when manufacturing the motor core 10 will be described.
[0030]
First, a blank sheet made of a steel plate is punched out by press forming to form the outer shapes of the plates 11A and 11B. At the same time, the projection 15 and a projection (not shown) slightly lower than the height of the caulking projection 14 are formed.
[0031]
Next, the plates 11 </ b> A and 11 </ b> B are alternately stacked using a low protrusion (not shown) as a positioning reference. Furthermore, as shown in FIG. 6, the board 11C is laminated | stacked on it, and a laminated body is obtained by this. Note that the plate 11C is also formed with a projection that is slightly lower than the caulking projection 14 shown in FIG. 6, and serves as a reference for positioning when laminating.
[0032]
Next, the laminated body is caulked again at the position of the shallow protrusion described above, and the motor core 10 made of a plurality of plates is obtained. Note that, by caulking firmly, the shallow protrusion described above becomes the shape of the caulking protrusion 14. In this case, since the convex portion 15 is provided in the vicinity of the caulking protrusion 14, the plates 11A and 11B adjacent to each other after caulking are arranged in parallel to each other as shown in FIG. Can be made constant. That is, when the convex portion 15 is arranged apart from the caulking projection portion 14, it is considered that the vicinity of the caulking projection portion 14 of the plates 11A and 11B is warped, but according to the present embodiment. There is no such problem.
[0033]
As shown in FIG. 1, the electric motor core 10 manufactured in this way is assembled in the casing 1 together with other components such as the compression portion 5, thereby obtaining a compressor. The motor core 10 is attached to the inner peripheral surface of the casing 1 by press fitting or shrink fitting.
[0034]
Next, the operation of the electric motor core 10 will be described.
[0035]
When the compressor is operated, the refrigerant gas is discharged from the compressor 5, and the winding 8 of the electric motor 6 and the electric motor core 10 placed in the refrigerant gas discharge path vibrate by receiving the pulsation of the refrigerant gas. In this case, the plate in the range of 10 to 20 mm from the lower end where the refrigerant gas collides among the motor core 10 is formed with a gap between the plates 11A and 11B adjacent to each other, so that the motor core 10 has sufficient vibration damping performance. have.
[0036]
FIG. 4A shows the vibration acceleration characteristics of a conventional motor core (see FIG. 6) in which all the plates constituting the motor core are in close contact with each other, and FIG. 4B shows the vibration acceleration of the motor core according to the present invention. The characteristics of As apparent from comparison between FIG. 4A and FIG. 4B, the motor core according to the present invention has faster vibration focusing and significantly better vibration damping performance than the conventional motor core. Yes.
[0037]
For this reason, the transmission of vibration to the casing 1 is greatly reduced, and as a result, the transmission of vibration to accessories such as the suction cup 4 and the terminal box cover 9 attached to the casing 1 is also greatly reduced. For this reason, a compressor with less vibration and noise can be obtained.
[0038]
FIG. 5 shows comparison of vibration transmissibility characteristics (distribution of vibration transfer function for each frequency) of a compressor assembled with a conventional motor iron core and vibration transmissibility characteristics of a compressor assembled with a motor iron core according to the present invention. Show. As shown in FIG. 5, the compressor assembled with the motor core according to the present invention has vibration transmissibility characteristics far superior to the compressor assembled with the conventional motor core, and in particular, 735 Hz. The transfer function in the nearby frequency band is significantly lower.
[0039]
【The invention's effect】
As described above, according to the present invention, an electric motor core having sufficient vibration damping performance can be obtained. For this reason, a compressor with low vibration and noise can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a compressor.
FIG. 2 is a plan view of an electric motor core.
FIG. 3 is a view showing a laminated state of plates constituting the motor iron core, and is a view showing an AA cross section of FIG. 2;
FIG. 4 is a diagram showing vibration acceleration characteristics of a conventional motor core and a motor core according to the present invention.
FIG. 5 shows a comparison of vibration transmissibility between a conventional compressor and a compressor according to the present invention.
FIG. 6 is a view showing a laminated state of plates constituting a conventional electric motor core.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Casing 2 Discharge port 5 Compression part 6 Electric motor 10 Electric motor core 11A, 11B Board 14 Caulking protrusion (caulking part)
15 Convex

Claims (3)

A compression section and an electric motor arranged in the casing;
The motor core of the motor is composed of a plurality of laminated and caulked plates, and at least a plate within a predetermined range among the plurality of plates has a thickness on each plate so that a gap is formed between adjacent plates. A convex part protruding in the vertical direction is formed ,
When the distance between adjacent plates is h 1 , the height of the caulking portion is h 2 , and the thickness of the plate is t, h 1 , h 2 and t are
0.2t <h 1 <2t,
And t + h 1 <h 2 ,
A compressor characterized by satisfying the following relationship . The compressor according to claim 1 , wherein the convex portion is provided in the vicinity of the caulking portion. The compressor according to claim 1 or 2, wherein the positions of the convex portions formed on the plates adjacent to each other are different.

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