JPH0674153A - Closed compressor - Google Patents

Abstract

PURPOSE:To prevent resonance noise in a container for lower noise by restricting a relational ratio between the maximum distance between inner wall surfaces in the reciprocating direction of a piston, the maximum distance between inner wall surfaces which cross orthogonally to it, and the maximum distance from the inner wall surface in the axial direction of a crank shaft to a lubricating oil surface. CONSTITUTION:In a sealed container 2, a motor-driven compression element 5 consisting of a compression part 6 and a motor part 7 is stored, at the bottom part of which lubricating oil is gathered. The maximum distance between the inner wall surfaces in the reciprocating direction of a piston 11, the maximum distance between inner wall surfaces which cross orthogonally to it, and the maximum distance from the inner wall surface in the axial direction of a crank shaft 12 to a lubricating oil surface are constituted so that when the shortest one of the above maximum distances is taken as 1, the other two distances may be within a range of (1.07-1.12) or (1.18-1.24). It is, thus possible to avoid respective resonance frequency in the reciprocating direction of the piston 11 in the container 2, a right-angled direction to it, and the axial direction of the crank shaft 12 from excitation frequency, preventing the generation of resonance noise in the container 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closed container of a reciprocating hermetic compressor used in a refrigerating machine or the like.

[0002]

2. Description of the Related Art Recent hermetic compressors are strongly desired to have low noise in terms of amenities. Therefore, regarding the shape of the closed container for preventing the generation of resonance noise in the closed container, for example, there is a closed container as disclosed in Japanese Patent Publication No. 3-53476.

An example of the above-mentioned conventional closed container will be described below with reference to the drawings. FIG. 7 shows a closed container of a conventional closed type compressor. In FIG. 7, 1 is a hermetic compressor, and 2 is a hermetic container, which is composed of a lower shell 3 and an upper shell 4 which are mutually connected via a welded portion. Reference numeral 5 indicated by a broken line is an electric compression element, which is housed in the closed container 2. The closed container 2 is shaped such that a straight line drawn at a right angle to an arbitrary wall portion intersects with the opposite wall portion at an angle different from 90 °.

With the above-described structure, the sound wave which hits one wall portion of the closed container is prevented from being reflected by the opposite wall portion, and further prevented from being amplified by the subsequent reflection. Therefore, since the opposing walls of the closed container do not generate any inherent resonance, sound waves having an excitation frequency that is an integral multiple of the operating frequency of the compressor do not easily propagate, and a closed noise compressor with low noise can be obtained.

[0005]

However, in the above-mentioned conventional structure, the angle at which a straight line drawn at right angles to an arbitrary wall portion of the closed container intersects with the opposite wall portion is greatly deviated from 90 °. Although the resonance sound is greatly attenuated, the shape of the closed container becomes distorted in order to largely shift the angle from 90 °, and the rigidity of the closed container is reduced, so that noise due to vibration of the closed container is generated. It gets bigger.

If the shape of the closed container is distorted,
The space in the closed container cannot be effectively used, and the closed container may become larger than necessary. On the contrary, if you try to increase the rigidity by making the closed container nearly spherical and reduce the noise due to the vibration of the closed container, the straight line drawn at right angles to any wall part of the closed container is on the opposite side. The angle intersecting with the wall portion approaches 90 °, and it is not possible to increase the attenuation of resonance sound in the closed container.

[0007] Normally, the lubricating oil is stored in the bottom of the closed container, and although the resonance sound propagating in the vertical direction is reflected by the oil surface of the lubricating oil, this is not taken into consideration. Therefore, there is a problem that a straight line drawn at a right angle to the oil surface intersects with the opposite upper shell portion at 90 °, and a resonance sound is generated depending on conditions.

The present invention solves the conventional problems, and an object of the present invention is to prevent the generation of resonance noise in a hermetic container and to provide an extremely low noise hermetic compressor.

[0009]

To achieve this object, a hermetic compressor of the present invention includes an electric compression element including a compression section such as a piston, a connecting rod, a crankshaft, and a motor section, and the electric compression element. The maximum distance between the inner wall surfaces of the piston and the inner wall surface in the reciprocating direction of the piston, the maximum distance between the inner wall surfaces in the direction perpendicular to the reciprocating direction of the piston, and the axial direction of the crankshaft When the shortest distance of the maximum distance from the inner wall surface of the to the lubricating oil surface is 1,
The remaining two distances are (1.07 to 1.12) or (1.
18 to 1.24) and a closed container within the range of 18-1.24).

Further, an electric compression element including a compression portion such as a piston, a connecting rod, a crankshaft, and a motor portion, and the electric compression element are stored, and a lubricating oil is stored at a bottom portion.
And the maximum distance between the inner wall surfaces in the reciprocating direction of the piston, the maximum distance between the inner wall surfaces in the direction perpendicular to the reciprocating direction of the piston, and the maximum distance from the inner wall surface in the axial direction of the crankshaft to the lubricating oil surface. If the shortest distance is 1, the remaining 2
Two distances are (1.07-1.10) or (1.33-
1.35) and a closed container within the range.

Further, an electric compression element including a compression portion such as a piston, a connecting rod, a crankshaft, and a motor portion, and the electric compression element are stored, and a lubricating oil is stored in a bottom portion,
And the maximum distance between the inner wall surfaces in the reciprocating direction of the piston, the maximum distance between the inner wall surfaces in the direction perpendicular to the reciprocating direction of the piston, and the maximum distance from the inner wall surface in the axial direction of the crankshaft to the lubricating oil surface. If the shortest distance is 1, the remaining 2
Two distances are (1.18 ~ 1.21) or (1.33 ~
1.35) and a closed container within the range.

[0012]

According to the present invention, the resonance frequency in the reciprocating direction of the piston in the sealed container, the direction perpendicular to the reciprocating direction of the piston, and the axial center direction of the crankshaft in the hermetic container is an integer of the operating frequency of the compressor body. It is possible to avoid the double frequency, that is, the excitation frequency, and it is possible to prevent the generation of resonance noise in the closed container.

Furthermore, since the curvature of the upper shell can be increased, the area of the wall portion parallel to the oil surface of the lubricating oil at the bottom of the closed container can be reduced, and the resonance noise is generated due to the change of the lubricating oil surface height due to the change of the lubricating oil amount. Even when the noise occurs, the level is suppressed to a low level, and a stable resonance sound reducing effect can be obtained. Also,
Since the curvature of the upper shell can be increased, the rigidity can be increased and the noise caused by the vibration of the closed container can be reduced.

Further, even when the pressure and temperature in the closed container fluctuate, the resonance frequency must be avoided, that is, the resonance frequency is avoided from the common excitation frequency when the power source frequency is 50 Hz and 60 Hz, and a stable resonance sound is obtained. A reduction effect can be obtained. In addition, since the curvature of the side surface of the closed container can be increased, the area of the wall portion that is parallel between the facing walls of the side surface of the closed container can be reduced, and even if resonance noise occurs due to pressure and temperature fluctuations inside the closed container, The level is suppressed to a low level, and a stable resonance sound reduction effect is obtained. Moreover, since the curvature of the side surface of the closed container can be increased, the rigidity can be increased, and the noise generated by the vibration of the closed container can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. It should be noted that the same components as those of the related art will be denoted by the same reference numerals and detailed description thereof will be omitted.

1 and 2 show a first example of the hermetic compressor of the present invention.
1 and 2 showing the embodiment of the present invention, reference numeral 1 is a hermetic compressor, and in the hermetic container 2, a coil spring 8 is arranged so that a compression section 6 is located above and a motor section 7 is located below.
It is elastically supported by. The compression unit 6 is composed of a cylinder 10, a piston 11, a crankshaft 12, a connecting rod 13, a bearing 14 and the like which are integrally provided with the block 9. The motor unit 7 is composed of a rotor 15 and a stator 16. The rotor 15 is shrink-fitted and fixed to the crankshaft 11, and the stator 16 is screwed and fixed to the block 9, so that the compression unit 6 and the motor part 7 are integrated to form an electric compression element 5
Is formed. a is a piston 11 on the inner surface of the closed container 2.
Is the maximum distance in the direction perpendicular to the reciprocating direction, b is the maximum distance in the reciprocating direction of the piston 11 on the inner surface of the closed container 2, and c is the maximum distance in the axial direction of the crankshaft 12 from the inner surface of the closed container 2 to the oil surface. Then, a = 133 mm, b = 145 mm, c = 16
0 mm, and their ratio a: b: c is 1: 1.09 :.
It is 1.20.

The operation of the hermetic compressor having the above structure will be described below. Resonance sound is generated in the closed container 2 when the resonance frequency in the closed container 2 and an integral multiple of the operating frequency of the closed type compressor, that is, the excitation frequency match.

Assuming that the power source frequency of the hermetic compressor is 50 Hz and 60 Hz, the operating frequencies thereof are 47-
It becomes 49.5Hz and 57-59.5Hz. Considering the conventional size of reciprocating hermetic compressors used in freezers and refrigeration equipment, the frequencies that cause problems with these higher-order components are 9th and 10th orders of rotation frequency when the power supply frequency is 50Hz. , 11
These are the 12th, 12th, and 13th order components, and in the case of 60Hz, 7th order,
They are the 8th, 9th, 10th, and 11th order components. Considering that the damping effect of the resonance is large, a wide range of ± 5 Hz is applied to the intermittent frequency bands that cover each of these frequency bands, and these frequency bands are 399 to 450.5 Hz, 45
1-500Hz, 508-549.5Hz, 559-600
Hz, 606 to 659.5 Hz. The resonance frequency of the closed container 2 may be determined while avoiding these frequency bands. That is, the resonance frequency is 450.5 to 451 Hz, 500 to 50
If the frequencies are set to 8 Hz, 549.5 to 559 Hz, and 600 to 606 Hz, the generation of resonance sound can be prevented. These frequency bands will be referred to as frequency bands I, II, III, and IV in ascending order.

In general, regarding the resonance sound generated between the opposing walls, there is a relationship of (Equation 1) among the distance L between the two walls, the resonance frequency f, and the sound velocity C of the medium.

[0020]

[Equation 1]

Applying this relationship to a hermetic compressor, L
Is the distance between the inner surfaces of the airtight containers 2 that face each other, f is the resonance frequency that can occur between the inner surfaces of the airtight containers 2 that face each other, and C is the speed of sound of the refrigerant in the airtight container 2. That is, the closed container 2
So that the resonance frequency of each of them is in the range of the frequency bands I to IV, the lengths a, b, c of the inner surface of the closed container 2 in the respective directions.
If you decide, no resonance will be generated. However, in reality, because of the influence of the electric compression element 5 in the closed container 2 and the like, it is slightly deviated from L calculated in (Equation 1), so it is necessary to apply a correction coefficient obtained by comparison with the result of acoustic experiment or numerical diffraction, The correction value is 0.9 based on our acoustic experiments and numerical analysis.
I know it is 39.

1 and 2, the distances a, b, c in each direction
Is the sound velocity in a closed container under the actual operating conditions,
It has been confirmed by our analysis and experiments that they correspond to the frequency bands IV, III, and II, respectively. Therefore, the resonance frequency in the hermetic container 2 can be avoided from an integral multiple of the operating frequency of the hermetic compressor, that is, the excitation frequency, and the generation of resonance noise in the hermetic container 2 can be prevented.

As described above, the hermetic compressor of this embodiment accommodates the electric compression element 5 including the compression portion 6 such as the piston 11, the connecting rod 13, the crankshaft 12 and the motor portion 7, and the electric compression element 5. And store lubricant at the bottom,
And the maximum distance between the inner wall surfaces of the piston 11 in the reciprocating direction,
When the shortest distance between the maximum distance between the inner wall surfaces of the piston 11 at right angles to the reciprocating direction and the maximum distance from the inner wall surface of the crankshaft 12 in the axial direction to the lubricating oil surface is 1, the remaining Since the two distances are composed of the closed container 2 in the range of (1.07 to 1.12) or (1.18 to 1.24), the reciprocating direction of the piston 11 in the closed container 2, A direction perpendicular to the reciprocating direction of the piston 11,
Each resonance frequency in the axial direction of the crankshaft 12 can be avoided from an integral multiple of the operating frequency of the hermetic compressor, that is, the excitation frequency, and resonance noise in the hermetic container 2 can be prevented.

In this embodiment, the frequency band IV,
In each direction of the closed container 2 corresponding to III, II, a,
Although b and c are determined, the same effect can be obtained by determining the directional distances a, b and c of the closed container 2 corresponding to the frequency bands III, II and I. Even in that case, each direction distance a,
When the shortest distance of b and c is 1, the remaining two distances are (1.07 to 1.12) or (1.18 to 1.
Within the range of 24).

Next, a second embodiment of the hermetic compressor of the present invention will be described with reference to the drawings. The same components as those in the conventional example and the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 3 and FIG. 4 show a second example of the hermetic compressor of the present invention.
FIG. 3 and 4, the distances a, b, and c in each direction are a = 133 mm and b = 145, respectively.
mm, c = 178 mm, and their ratio a: b: c is 1 :.
It is 1.09: 1.34.

The operation of the hermetic compressor constructed as described above will be described below. In FIGS. 3 and 4, the distances a, b, and c in the respective directions correspond to the frequency bands IV, III, and I shown in the first embodiment at the sound velocity in the closed container under the actual operating conditions. Confirmed by our analysis and experiments. Therefore, the resonance frequency in the hermetic container 2 can be avoided from an integral multiple of the operating frequency of the hermetic compressor, that is, the excitation frequency, and the generation of resonance noise in the hermetic container 2 can be prevented.

Further, since the distance c is considerably larger than the distances a and b, it is possible to make the curved surface of the upper shell 4 into a substantially spherical shape having a large curvature, and the lubricating oil stored in the bottom of the closed container 2 is frozen and refrigerated. Even if the oil level height fluctuates and the resonance frequency fluctuates by flowing out to the device, the area of the wall portion parallel to the oil surface is small due to the large curvature of the upper shell, and even if resonance noise occurs, The level can be kept small. Further, since the upper shell 4 has a substantially spherical shape, the rigidity is great and the noise generated due to the vibration of the closed container 2 can be reduced.

As described above, the hermetic compressor of this embodiment accommodates the electric compression element 5 including the compression portion 6 such as the piston 11, the connecting rod 13, the crankshaft 12 and the motor portion 7, and the electric compression element 5. And store lubricant at the bottom,
And the maximum distance between the inner wall surfaces of the piston 11 in the reciprocating direction,
When the shortest distance between the maximum distance between the inner wall surfaces of the piston 11 at right angles to the reciprocating direction and the maximum distance from the inner wall surface of the crankshaft 12 in the axial direction to the lubricating oil surface is 1, the remaining Since the two distances are composed of the closed container 2 within the range of (1.07 to 1.10) or (1.33 to 1.35), the reciprocating direction of the piston 11 in the closed container 2, A direction perpendicular to the reciprocating direction of the piston 11,
Each resonance frequency in the axial direction of the crankshaft 12 can be avoided from an integral multiple of the operating frequency of the hermetic compressor, that is, the excitation frequency, and resonance noise in the hermetic container 2 can be prevented.

Further, since the distance c is considerably larger than the distances a and b, the curved surface of the upper shell 4 can be formed into a substantially spherical shape having a large curvature, and the lubricating oil stored in the bottom of the closed container 2 can be frozen and refrigerated. Even if the height of the oil surface fluctuates and the resonance frequency fluctuates due to the outflow to the oil surface, the area of the wall portion parallel to the oil surface is small due to the large curvature of the upper shell 4, and even if a resonance sound is generated, The level can be kept small. Further, since the upper shell 4 has a substantially spherical shape, the rigidity is great and the noise generated due to the vibration of the closed container 2 can be reduced.

Next, a third embodiment of the hermetic compressor of the present invention will be described with reference to the drawings. Incidentally, the conventional example,
The same components as those in the first and second embodiments are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 4 and FIG. 5 show a second example of the hermetic compressor of the present invention.
FIG. 4 and 5, the distances a, b, and c in each direction are a = 160 mm and b = 178, respectively.
mm, c = 133 mm, and their ratio a: b: ac is 1.20: 1.34: 1.

The operation of the hermetic compressor constructed as described above will be described below. 4 and 5,
According to our analysis and experiments, the distances a, b, and c correspond to the frequency bands II, I, and IV shown in the first embodiment, respectively, at the sound velocity in the closed container under the actual operating conditions. It has been confirmed. Therefore, the resonance frequency in the hermetic container 2 can be avoided from an integral multiple of the operating frequency of the hermetic compressor, that is, the excitation frequency, and the generation of resonance noise in the hermetic container 2 can be prevented.

Further, the excitation frequency that must be avoided, that is, the frequency band shown in the first embodiment, is close to the excitation frequency common to the power source frequency of 50 Hz and 60 Hz.
The distance corresponding to III is the distance a in each direction in the closed container 2,
Not used for b and c. Therefore, even when the pressure and temperature in the closed container 2 fluctuate, the resonance frequency of the closed container 2 can be avoided from the excitation frequency that must be avoided, and a stable resonance sound reduction effect can be obtained.

Further, since the distances a and b are considerably larger than the distance c, it is possible to make the curvature in the vicinity of the welded portion of the upper shell 4 and the lower shell 3, that is, the side surface of the closed container 2 larger than usual. Even if the temperature, pressure, etc. of the refrigerant in 2 fluctuate and the resonance frequency fluctuates, the side wall of the closed container 2 has a large curvature, so that the area of the walls parallel to each other is small and the resonance noise Even if a problem occurs, the level can be kept small. Further, since the side surface of the hermetically sealed container 2 has a large curvature, the rigidity thereof is great, and noise generated by the vibration of the hermetically sealed container 2 can be reduced.

As described above, the hermetic compressor of this embodiment accommodates the electric compression element 5 including the compression portion 6 such as the piston 11, the connecting rod 13, the crankshaft 12 and the motor portion 7, and the electric compression element 5. And store lubricant at the bottom,
And the maximum distance between the inner wall surfaces of the piston 11 in the reciprocating direction,
When the shortest distance between the maximum distance between the inner wall surfaces of the piston 11 at right angles to the reciprocating direction and the maximum distance from the inner wall surface of the crankshaft 12 in the axial direction to the lubricating oil surface is 1, the remaining Since the two containers are composed of the closed container 2 whose distance is within the range of (1.18 to 1.21) or (1.33 to 1.35), the reciprocating direction of the piston 11 in the closed container 2, A direction perpendicular to the reciprocating direction of the piston 11,
Each resonance frequency in the axial direction of the crankshaft 12 can be avoided from an integral multiple of the operating frequency of the hermetic compressor, that is, an excitation frequency, and resonance noise in the hermetic container 2 can be prevented.

Further, even when the pressure, temperature, etc. in the closed container 2 fluctuate, the resonance frequency of the closed container 2 can be avoided from the excitation frequency that must be avoided, and a stable resonance sound reduction effect can be obtained. Further, even if the resonance frequency fluctuates due to fluctuations in the temperature, pressure, etc. of the refrigerant in the closed container 2, the level can be suppressed to a low level even when the resonance sound reflected by the side surface of the closed container 2 is generated. Further, since the side surface of the hermetically sealed container 2 has a large curvature, the rigidity thereof is great, and noise generated by the vibration of the hermetically sealed container 2 can be reduced.

[0038]

As described above, according to the present invention, an electric compression element including a compression portion such as a piston, a connecting rod, a crankshaft, and a motor portion and the electric compression element are housed.
In addition, the maximum distance between the inner wall surfaces of the piston that stores the lubricating oil in the bottom and the reciprocating direction of the piston, the maximum distance between the inner wall surfaces of the piston perpendicular to the reciprocating direction, and the inner wall surface of the crankshaft in the axial direction When the shortest distance among the maximum distances from the to the lubricating oil surface is 1, the remaining two distances are (1.07 ~
1.12) or (1.18 to 1.24) within the closed container, the piston reciprocates in the closed container, the direction perpendicular to the reciprocating direction of the piston, the crankshaft. The respective resonance frequencies in the axial direction can be avoided from an integral multiple of the operating frequency of the compressor body, that is, the excitation frequency, and the generation of resonance noise in the closed container can be prevented.

Further, an electric compression element including a compression portion such as a piston, a connecting rod, a crankshaft, and a motor portion, and the electric compression element are housed, and lubricating oil is stored in the bottom portion.
And the maximum distance between the inner wall surfaces in the reciprocating direction of the piston, the maximum distance between the inner wall surfaces in the direction perpendicular to the reciprocating direction of the piston, and the maximum distance from the inner wall surface in the axial direction of the crankshaft to the lubricating oil surface. If the shortest distance is 1, the remaining 2
Two distances are (1.07-1.10) or (1.33-
Since it is composed of a closed container within the range of 1.35), the resonance frequencies of the reciprocating direction of the piston in the closed container, the direction perpendicular to the reciprocating direction of the piston, and the axial direction of the crankshaft are determined. It can be avoided from an integral multiple of the operating frequency of the compressor body, that is, the excitation frequency, and the generation of resonance noise in the closed container can be prevented. Further, since the curvature of the upper shell can be increased, the area of the wall portion parallel to the oil surface of the lubricating oil at the bottom of the closed container can be reduced, and resonance noise is generated due to the change of the lubricating oil surface height due to the change of the lubricating oil amount. Even in such a case, the level can be suppressed to a low level, and a stable resonance sound reducing effect can be obtained. Further, since the curvature of the upper shell can be increased, the rigidity can be increased and the noise generated due to the vibration of the closed container can be reduced.

Further, an electric compression element including a compression portion such as a piston, a connecting rod, a crankshaft, and a motor portion, and the electric compression element are stored, and lubricating oil is stored at the bottom.
And the maximum distance between the inner wall surfaces in the reciprocating direction of the piston, the maximum distance between the inner wall surfaces in the direction perpendicular to the reciprocating direction of the piston, and the maximum distance from the inner wall surface in the axial direction of the crankshaft to the lubricating oil surface. If the shortest distance is 1, the remaining 2
Two distances are (1.18 ~ 1.21) or (1.33 ~
Since it is composed of a closed container within the range of 1.35), the resonance frequencies of the reciprocating direction of the piston in the closed container, the direction perpendicular to the reciprocating direction of the piston, and the axial direction of the crankshaft are determined. It can be avoided from an integral multiple of the operating frequency of the compressor body, that is, the excitation frequency, and the generation of resonance noise in the closed container can be prevented.

Further, even when the pressure and temperature in the closed container fluctuate, the resonance frequency should be avoided, that is, the resonance frequency should be avoided from the common excitation frequency when the power source frequency is 50 Hz and 60 Hz, and a stable resonance sound should be avoided. A reduction effect can be obtained. In addition, since the curvature of the side surface of the closed container can be increased, the area of the wall portion that is parallel between the facing walls of the side surface of the closed container can be reduced, and even if resonance noise occurs due to pressure and temperature fluctuations inside the closed container, The level is suppressed to a low level, and a stable resonance sound reduction effect is obtained. Moreover, since the curvature of the side surface of the closed container can be increased, the rigidity can be increased, and the noise generated by the vibration of the closed container can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a hermetic compressor showing a first embodiment of the present invention.

FIG. 2 is a plan view of a hermetic compressor showing a first embodiment of the present invention.

FIG. 3 is a cross-sectional view of a hermetic compressor showing a second embodiment of the present invention.

FIG. 4 is a plan view of a hermetic compressor showing a second embodiment of the present invention.

FIG. 5 is a transverse sectional view of a hermetic compressor showing a third embodiment of the present invention.

FIG. 6 is a plan view of a hermetic compressor showing a third embodiment of the present invention.

FIG. 7 is a side view of a conventional hermetic compressor.

[Explanation of symbols]

 2 Airtight container 5 Electric compression element 6 Compression part 7 Motor part 11 Piston 12 Crankshaft 13 Connecting rod

Claims (3)

[Claims] 1. An electric compression element comprising a compression section such as a piston, a connecting rod, a crankshaft, etc. and a motor section, and the electric compression element is housed, and lubricating oil is stored in the bottom part thereof. The maximum distance between the wall surfaces and the maximum distance between the inner wall surfaces in the direction perpendicular to the reciprocating direction of the piston,
When the shortest distance among the maximum distances from the inner wall surface in the axial direction of the crankshaft to the lubricating oil surface is 1, the remaining two distances are (1.07 to 1.12) or (1.18 to 1). .2
A hermetic compressor comprising a hermetic container within the range of 4). 2. An electric compression element comprising a compression section such as a piston, connecting rod, crankshaft, etc. and a motor section, and the electric compression element is housed, and lubricating oil is stored in the bottom part thereof. The maximum distance between the wall surfaces and the maximum distance between the inner wall surfaces in the direction perpendicular to the reciprocating direction of the piston,
When the shortest distance among the maximum distances from the inner wall surface in the axial direction of the crankshaft to the lubricating oil surface is 1, the remaining two distances are (1.07 to 1.10) or (1.33 to 1). .3
A hermetic compressor comprising a hermetic container within the range of 5). 3. An electric compression element comprising a compression portion such as a piston, connecting rod, crankshaft and the like, and a motor portion, and the electric compression element is housed therein, and lubricating oil is stored in the bottom portion thereof. The maximum distance between the wall surfaces and the maximum distance between the inner wall surfaces in the direction perpendicular to the reciprocating direction of the piston,
When the shortest distance among the maximum distances from the inner wall surface in the axial direction of the crankshaft to the lubricating oil surface is 1, the remaining two distances are (1.18 to 1.21) or (1.33 to 1). .3
A hermetic compressor comprising a hermetic container within the range of 5).