JPS6019993Y2 - Hermetic electric compressor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hermetic electric compressor that prevents resonance of a hermetic case.

Generally, in a hermetically sealed electric compressor, the vibration generated by the electric compressor housed inside the hermetically sealed case causes a resonance phenomenon between the hermetically sealed case and can become a source of large noise.

Therefore, countermeasures have been taken, such as making the shape of the sealed case spherical or making its horizontal cross section approximately elliptical.

However, this mainly has the effect of simply increasing the rigidity and shifting the resonance frequency to a higher side, and has not been able to sufficiently reduce vibrations and fluctuations in low-order modes.

Especially in a substantially oval case, if the radius is divided into a large radius and a small radius, the radius of the large radius is larger than that of the circular case, so the rigidity of that part will be weaker, especially in the case. If the plate thickness is thin, the rigidity of the large radius portion will be extremely weak, causing the first resonance frequency to be in an extremely low region.

The present invention has been made to solve these problems.

The following Figures 1, 2, and 3 show one embodiment of the present invention.
This will be explained with reference to the diagram.

In the figure, 1 is the first case, 2 is the second case,
Both cases 1 and 2 form a substantially elliptical dome-shaped airtight container, and a motor compressor unit 3 consisting of an electric motor 3a and a compression unit 3b driven by the motor 3a is housed inside.

Opening 1-a which is the welded part of the first and second cases 1 and 2
, 1-b has a pair of relatively large radius portions 1-a-1, 1-a-2 and a pair of relatively small radius portions 1-a-3, 1-a-4. It has a generally elliptical shape.

The first case 1 is close to the opening 1-a in the vertical direction, and has small rounded portions 1-a-3, 1-a-
The first one facing 4. A second corner portion 4-at4-b is formed.

The first and second corner portions 4-a and 4-b are smaller in curvature than the small radius portion 1-a L 1 a 4,
Furthermore, one of the large radius portions 1-a-1 has a large radius portion 1-a-1.
A third corner portion 4-c having a smaller curvature than a-1, 1-a-2 is arranged, and each corner portion 4-a, 4-b, 4-c
Raise it towards the vertex 5, ridge lines 5-a, 5-b,
5-c, and a curved surface 6 with a relatively large curvature between each ridgeline.
Connected by -a, 6-b, and 6-c.

Also,? -a, ? -b, ? -c is the curved surface 6-a,
It is a crescent-shaped inclined surface connecting 6-b, 6-c and opening 1-a.

Further, the second case 2 does not have a corner part unlike the first case 1, and has a simple elliptical half-dome.

The same parts as those in the first case in FIG. 2 are given the same reference numbers and their explanations will be omitted.

Next, the operation of this configuration will be explained.

Generally, in a cylindrical or spherical case, the horizontal cross section is circular, so the low-order vibration takes a clean mode with the antinode at the excitation position.

For this purpose, methods have been taken to break the axial symmetry by making the horizontal cross-sectional shape elliptical, but these are basically a series of continuous circular shapes, and a sufficient asymmetrical effect cannot be obtained.

Therefore, since the second case 2 has an elliptical cross section, the low-order mode vibration is somewhat distorted compared to a cylindrical or spherical case, but the vibration is sufficient. It was not possible to obtain a damping effect.

Furthermore, in the case of the present invention, since the case plate thickness is extremely thin, the rigidity of the large radius portion of the second case is extremely weak.

Therefore, the first case 1 has three corner portions 4-a, 4-b, and 4-c and curved surface portions 6-a and 6 with a radius larger than that of the opening connecting them, as shown in FIG. −
The asymmetrical shape formed by b and 6-c complicates the vibration shape of the lower-order mode of the case, making it difficult for the case to resonate at specific frequencies, and also making it difficult for the case to resonate at certain frequencies. 4-c was placed approximately in the center of the less rigid surface 1-a-1 of the second case 2.

By welding this first case 1 to the second case 2 at the bottom, the difficulty of resonance in the first case 1 at the top has a damping effect on the second case at the bottom, and furthermore, the second case 1 at the bottom has a damping effect.
By placing the corner portion 4-c of the first case 1 on the less rigid surface 1-a-1 of the case 2, the second case 2
The rigidity of the case has also been increased, making the case as a whole less likely to resonate.
Furthermore, it is made to have sufficient strength in terms of rigidity.

As a result, even though the plate thickness has been reduced, the resonance Q value (peak sharpness) in the frequency response curve of the case is small, and the case has sufficient rigidity, resulting in stable noise control. reduction and rationalization of case materials.

In the above embodiment, only the corner part 4 is provided in the first case 1.
-a, 4-b, and 4-c are formed, but the second case 2 may be used alone, or the same effect can be obtained by forming them in both cases 1 and 2.

Furthermore, in the above embodiment, two corner portions are placed in the small radius portion and one corner portion is placed in the large radius portion, but
On the contrary, part of two corners are placed in the large radius part, and one corner is placed in the small radius area.
Exactly the same effect can be obtained by arranging some of the corners of

As described above, the present invention consists of upper and lower dome-shaped cases each having a substantially elliptical opening having a large radius portion and a small radius portion with different curvatures. to provide three corner portions, and furthermore, the first
．． Second. Inside the sealed case, the ridgeline extends from a part of the third corner toward the apex, and each ridgeline is continuous with a curved surface.
By housing the electric compression element, the case shape provides a damping effect on case vibration, and the rigidity of the case is increased, allowing for stable noise reduction of the hermetic electric compressor and streamlining of the case members.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a hermetic electric compressor showing an embodiment of the present invention, FIG. 2 is a top view of the same, and FIG. 3 is a perspective view of the case. 1...First case, 2...Second case, 3...Motor compressor unit, 1a
1?1-a-2...Large R section, 1-a-
3, 1-a-4...Small round part, 4-a...
...Part of the first corner, 4-b...Part of the second corner, 4-c...Part of the third corner, 5...
...Vertex, 5-a? 5-by 5-c...Ridge, 6-a, 6-b, 6-c"" curved surface.

Claims (1)

[Scope of utility model registration request] In a case in which a motor compressor unit consisting of an electric motor and a compression element is housed in a dome-shaped case having a substantially elliptical top and bottom, at least one of the cases has an opening having a pair of large rounded portions with a relatively large curvature. It has a substantially elliptical shape with a pair of small rounded portions having a relatively small curvature, and a portion of the three corners are located close to this opening, and a ridge line extends from the three corner portions toward the apex. , a hermetic electric compressor characterized by connecting each ridgeline with a curved surface.