WO2018138772A1

WO2018138772A1 - Closed-type compressor

Info

Publication number: WO2018138772A1
Application number: PCT/JP2017/002324
Authority: WO
Inventors: 暁和和泉
Original assignee: 三菱電機株式会社
Priority date: 2017-01-24
Filing date: 2017-01-24
Publication date: 2018-08-02

Abstract

A closed-type compressor according to the present invention is provided with: a compression mechanism part for compressing a refrigerant; an electric motor for driving the compression mechanism part; and a closed container for housing the compression mechanism part and the electric motor. The closed container is provided with: a cylindrical body portion; a cover portion having a circular cover shape, and provided with a notch section in an inner circumferential side of an edge section thereof; and a welded portion for bonding the body portion and the cover portion, wherein the notch section is fitted into an outer circumferential side of an edge section of the body portion so as to face the outer circumferential side in radial and axial directions.

Description

Hermetic compressor

The present invention relates to a hermetic compressor in which a body portion and a lid portion are joined.

In the hermetic compressor, the refrigerant is compressed by the compression mechanism included in the hermetic container, and the inside of the container becomes high pressure. In such a hermetic compressor, there is one in which a hermetic container is formed by welding a cylindrical body part and a circular lid part (for example, see Patent Document 1). Patent Document 1 discloses a scroll compressor in which a body portion is inserted into an opening portion of a lid portion.

By the way, in material mechanics, a sphere has a half tensile stress when an external force is applied, compared to a cylinder. For this reason, for example, a hemispherical lid portion is less deformed outwardly in the radial direction due to the internal pressure of the opening than the cylindrical body portion.

JP 2007-77850 A

As in Patent Document 1, in a hermetic compressor in which a hermetic container is formed by inserting and welding a circular lid-shaped lid portion on the inner peripheral surface of a cylindrical barrel portion, Due to the difference in the deformation amount, the gap between the body portion and the lid portion is enlarged when the internal pressure is applied. Therefore, the slip deformation in the elastic region generated in the welded portion joining the body portion and the lid portion increases, and the progress of fatigue fracture of the welded portion due to repeated operation and stoppage of the compressor may increase.

The present invention has been made to solve the above-described problems, and it is an object of the present invention to improve the fatigue life of the welded portion of the body portion and the lid portion of the sealed container of the hermetic compressor.

A hermetic compressor according to the present invention is a hermetic compressor including a compression mechanism unit that compresses a refrigerant, an electric motor that drives the compression mechanism unit, and a hermetic container that houses the compression mechanism unit and the electric motor. The sealed container joins the barrel portion and the lid portion to the barrel portion having a cylindrical shape, a lid shape having a circular lid shape, and a notch portion provided on the inner peripheral side of the edge portion. A welded portion, and the cutout portion is fitted so as to face the outer peripheral side of the edge portion of the body portion in the radial direction and the axial direction.

According to the hermetic compressor of the present invention, the lid portion having a small deformation amount at the time of applying internal pressure is joined to the outer peripheral side of the cylindrical barrel portion, and the edge portion of the trunk portion and the notch of the lid portion are cut out. The part is fitted in the radial direction and the axial direction. Therefore, the deformation of the edge of the body portion is suppressed by the notch portion of the lid portion in the radial direction and the axial direction, and expansion of the gap between the body portion and the lid portion when applying internal pressure is suppressed. As a result, the hermetic compressor can suppress slip deformation in the elastic region that occurs in the welded portion between the body portion and the lid portion.

It is sectional drawing which shows the hermetic compressor which concerns on Embodiment 1 of this invention. FIG. 2 is a cross-sectional view showing an AA cross section of the sealed container of FIG. 1. It is explanatory drawing which shows the edge part of the trunk | drum which concerns on Embodiment 1 of this invention, and the edge part of an upper cover part. It is a fragmentary sectional view which shows the fitting part of the trunk | drum which concerns on Embodiment 1 of this invention, and an upper cover part. It is a fragmentary sectional view which shows the state after the welding of the trunk | drum which concerns on Embodiment 1 of this invention, and an upper cover part.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a hermetic compressor according to Embodiment 1 of the present invention. A longitudinal sectional view of the hermetic compressor 1 in the installed state is shown. In FIG. 1, a sealed container 2 constituting an outer shell of a hermetic compressor 1 includes a cylindrical body portion 21, a circular lid-shaped upper lid portion 22, and a lower lid portion 23 (hereinafter sometimes collectively referred to as a lid portion). Etc.). In the axial direction (arrow Z direction), an upper lid portion 22 is disposed at the upper portion of the trunk portion 21, and a lower lid portion 23 is disposed at the lower portion, and the inner peripheral side of the edge portion of the lid portion is the outer peripheral side of the edge portion of the trunk portion 21. It is mated with. And the trunk | drum 21 and the cover part are mutually joined in the welding part 24 in the state which the edge part fitted. The sealed container 2 is provided above the pedestal 3, and the lower lid portion 23 is fixed to the pedestal 3. The hermetic compressor 1 is usually installed by fixing the pedestal 3 to an installation place with a bolt or the like.

The lid may have a configuration in which the amount of deformation is smaller than that of the body 21 at the edge disposed so as to overlap the outer peripheral side of the edge of the body 21. For example, the shape of the upper lid portion 22 and the lower lid portion 23 may be hemispherical, or may be a shape in which a flat plate-like upper surface and lower surface are connected to the opening side surface by a curved surface.

Inside the sealed container 2 are housed a compression mechanism 5 that compresses the refrigerant, an electric motor 4 that drives the compression mechanism 5, and the like. As the refrigerant, any refrigerant such as a natural refrigerant such as carbon dioxide (CO ₂ ), an HFC refrigerant, an HFO refrigerant, or an HC refrigerant may be used.

The electric motor 4 includes a stator 41 fixed to the inner peripheral surface of the body portion 21 of the sealed container 2, and a rotor 42 and the like disposed with a slight gap inside the stator 41. The stator 41 is fixed to the trunk portion 21 by, for example, spot welding or shrink fitting. The electric motor 4 is connected to a terminal 6a attached to the center portion of the upper lid portion 22 by a lead wire 6b, and electric power is supplied to the electric motor 4 through the terminal 6a.

The compression mechanism 5 includes a crankshaft 51, a cylinder 52, an upper bearing 53 and a lower bearing 54, a roller 55, a vane (not shown), and the like. The upper bearing 53 is fixed to the trunk portion 21 by spot welding or the like. The crankshaft 51 has an eccentric portion 51 a that is eccentric in one direction, and is inserted into and fixed to the central portion of the rotor 42 of the electric motor 4. The cylinder 52 forms a compression chamber 52a concentric with the crankshaft 51 in the inner peripheral portion. The upper bearing 53 and the lower bearing 54 support the crankshaft 51. An upper bearing 53 is disposed at the upper end of the cylinder 52, and a lower bearing 54 is disposed at the lower end of the cylinder 52. The roller 55 is attached to the eccentric part 51 a of the crankshaft 51 in the cylinder 52. The vane is inserted into a groove (not shown) provided in the cylinder 52, and partitions the compression chamber 52a into a high pressure side and a low pressure side.

The hermetic compressor 1 is used, for example, connected to the evaporator of the refrigeration cycle by the refrigerant suction pipe 7a and connected to the condenser of the refrigeration cycle by the refrigerant discharge pipe 7b.

The operation of the hermetic compressor 1 will be described. When electric power is supplied to the motor 4 through the terminal 6a, the crankshaft 51 fixed to the rotor 42 rotates around the rotation shaft 51b, and the refrigerant is sucked into the compression chamber 52a from the refrigeration cycle through the refrigerant suction pipe 7a. And compressed by the eccentric motion of the roller 55. The compressed high-pressure refrigerant is discharged into the sealed container 2, and the sealed container 2 is in a high pressure state. The high-pressure refrigerant in the sealed container 2 is discharged from the refrigerant discharge pipe 7b to the refrigeration cycle. The compression mechanism unit 5 and the electric motor 4 are installed in the sealed container 2 so that the rotation shaft 51b is disposed on the center line of the body unit 21.

FIG. 2 is a cross-sectional view showing an AA cross section of the sealed container of FIG. Based on FIG. 2, the stress which arises in a cover part and the trunk | drum 21 when an internal pressure is applied to the airtight container 2 is demonstrated. Hereinafter, the upper lid portion 22 will be described, and the edge portion of the lower lid portion 23 has the same shape as the edge portion of the upper lid portion 22, and the description of the lower lid portion 23 will be omitted.

In material mechanics, when an internal pressure is applied to a thin cylinder, the tensile stress σ uniformly generated on the circumference is expressed by the following formula (1) by the internal pressure p, the inner diameter r of the thin cylinder, and the plate thickness t. .

[Equation 1]
σ = p × r / t (1)

On the other hand, when internal pressure acts on the thin-walled sphere, the tensile stress σ is expressed by the following formula (2).

[Equation 2]
σ = p × r / 2t (2)

In the above formulas (1) and (2), when the inner diameter r, the plate thickness t, and the internal pressure p are made equal, the sphere has a half tensile stress σ compared to the cylinder. That is, when the cylindrical body portion 21 and the hemispherical upper lid portion 22 are compared, the deformation amount in the opening portion is smaller in the upper lid portion 22 having a smaller tensile stress σ when an internal pressure is applied. Therefore, when the edge of the upper lid portion 22 is arranged on the outer peripheral side of the edge portion of the trunk portion 21, when the internal pressure is applied, the hermetic container 2 is deformed radially outward in the trunk portion 21. Is suppressed by the upper lid portion 22.

3 and 4, the fitting structure between the body portion 21 and the upper lid portion 22 will be described. FIG. 3 is an explanatory diagram showing an edge portion of the trunk portion and an edge portion of the upper lid portion according to Embodiment 1 of the present invention. FIG. 4 is a partial cross-sectional view showing a fitting portion between the body portion and the upper lid portion according to Embodiment 1 of the present invention. 3 and 4 show a longitudinal section of the body portion 21 and the upper lid portion 22 in a region surrounded by a dotted line in FIG. 1, FIG. 3 shows a state before fitting, and FIG. 4 shows a state after fitting. To express.

The body portion 21 and the upper lid portion 22 are edged by cutting, for example. As shown in FIG. 3, the edge part of the trunk | drum 21 has a substantially rectangular cross section, for example. On the other hand, the edge part of the upper cover part 22 is provided with the notch part 25 notched over the end surface 22c on the inner peripheral side. The cutout portion 25 has a substantially L-shaped cross section, and is provided in an annular shape as a whole along the opening of the upper lid portion 22. Thus, the notch part 25 of the upper cover part 22 and the outer peripheral side of the trunk | drum 21 have a corresponding shape, and are comprised so that it may mutually fit. The cutout portion 25 of the upper lid portion 22 is formed, for example, by cutting the inner peripheral surface 22b to the end surface 22c with a constant depth so that a constant plate thickness t2 remains from the outer peripheral surface 22a. That is, a step is formed on the inner peripheral side of the edge portion of the upper lid portion 22 by the notch, and the plate thickness of the upper lid portion 22 is thinner at the edge portion than the portion outside the edge portion.

The configuration of the fitting part will be described in detail. The edge part of the trunk | drum 21 is an opening part of the cylindrical trunk | drum 21, Comprising: The end surface 21c located in an opening end, the outer peripheral surface 21a located in the opening end side, the inner peripheral surface 21b, etc. are comprised. . The outer peripheral surface 21a of the edge portion forms a part of the outer peripheral surface of the body portion 21, and is formed on the same surface as the outer peripheral surface outside the edge portion. The inner peripheral surface 21b of the edge portion forms a part of the inner peripheral surface of the body portion 21, and is formed on the same surface as the inner peripheral surface outside the edge portion. The outer peripheral surface 21a is disposed in a direction parallel to the inner peripheral surface 21b, and the end surface 21c is substantially 90 ° with respect to the outer peripheral surface 21a.

The edge portion of the upper lid portion 22 is an opening portion of the circular lid-shaped upper lid portion 22, and includes an end surface 22 c positioned at the opening end, an outer peripheral surface 22 a and an inner peripheral surface 22 b positioned on the opening end side, and the above-described cuts. It is comprised by the notch part 25 grade | etc.,. The cutout portion 25 has a cutout end surface 25a and a cutout inner peripheral surface 25b. The outer peripheral surface 22a of the edge portion forms a part of the outer peripheral surface of the upper lid portion 22, and is formed on the same surface as the outer peripheral surface outside the edge portion. The inner peripheral surface 22 b of the edge portion forms a part of the inner peripheral surface of the upper lid portion 22, and is formed on the same surface as the inner peripheral surface outside the edge portion outside the notch portion 25. Then, the notch inner peripheral surface 25b is disposed on the outer side in the radial direction (arrow X direction) than the inner peripheral surface 22b. And the level | step difference of the internal peripheral surface 22b and the notch inner peripheral surface 25b is connected by the notch end surface 25a. The outer peripheral surface 22a of the upper lid portion 22 is disposed in a direction parallel to the inner peripheral surface 22b and the cutout inner peripheral surface 25b, and the end surface 22c and the cutout end surface 25a are approximately 90 ° with respect to the outer peripheral surface 22a. Yes.

As shown in FIG. 4, the inner peripheral side of the edge portion of the upper lid portion 22 is fitted with the outer peripheral side of the edge portion of the trunk portion 21. In the fitted state, the notch end surface 25 a is opposed to the end surface 21 c of the trunk portion 21, and the notched inner circumferential surface 25 b is in contact with the outer circumferential surface 21 a of the trunk portion 21. Since the cutout portion 25 is provided along the opening of the upper lid portion 22, the edge portion of the trunk portion 21 has an annular cutout end surface 25 a extending in the radial direction (arrow X direction) and an axial direction ( Deformation is suppressed by the cylindrical cutout inner peripheral surface 25b extending in the direction of arrow Z (see FIG. 2). As described above, by arranging the edge of the upper lid portion 22 on the outer peripheral side of the edge portion of the trunk portion 21, the expansion of the gap between the trunk portion 21 and the upper lid portion 22 during application of internal pressure is suppressed, and the trunk portion 21. Slip deformation in the elastic region occurring in the welded portion 24 where the upper lid portion 22 and the upper lid portion 22 are joined is suppressed.

In addition, although the notch part 25 demonstrated as what was comprised by two surfaces, the notch end surface 25a and the notch inner peripheral surface 25b, it is not limited to this. The cutout portion 25 may have any shape as long as it has a shape in contact with the outer peripheral side of the edge portion of the body portion 21 in the radial direction and the axial direction.

Next, the dimensions of the cutout portion 25 of the upper lid portion 22 will be described. FIG. 3 shows the plate thickness t1 of the body portion 21, the plate thickness t2 on the outer peripheral side of the cutout portion 25, and the axial width t3 of the cutout portion 25.

From the above equation (2), at the edge of the upper lid portion 22, the tensile pressure increases as the plate thickness t2 decreases. When the upper lid portion 22 is hemispherical, when the plate thickness t2 is less than 0.5 times the plate thickness t1 of the barrel portion 21, the gap between the barrel portion 21 and the upper lid portion 22 during application of internal pressure is expanded. Sliding deformation in the elastic region generated in the welded portion 24 that joins the trunk portion 21 and the upper lid portion 22 becomes large. Therefore, it is desirable that the plate thickness t2 on the outer peripheral side of the cutout portion 25 be, for example, 0.5 times or more the plate thickness t1 of the trunk portion 21. The plate thickness t2 may be set according to the shape of the upper lid portion 22.

Further, as the axial width t3 of the notch portion 25 is reduced, the weld metal is likely to be melted to the inner peripheral surface 22b of the upper lid portion 22, and sputtering is easily mixed into the sealed container 2. In order to prevent mixing of spatter, the width t3 of the notch 25 needs to be ensured to be equal to or greater than the penetration depth of the weld 24. Therefore, in the first embodiment, for example, t1 = 6 mm, t2 = 5 mm, and t3 = 8.5 mm.

Based on FIG. 5, the welding method of the trunk | drum 21 and the upper cover part 22 of the airtight container 2 is demonstrated. FIG. 5 is a partial cross-sectional view showing a state after welding of the body portion and the upper lid portion according to Embodiment 1 of the present invention. As shown in FIG. 5, the trunk portion 21 and the upper lid portion 22 are joined by welding in a state where the edge portion of the trunk portion 21 is fitted to the cutout portion 25. As a welding method, for example, MAG welding (Metal Active Gas Welding) or the like may be employed. When welding is performed, the molten welding wire and the base metal of the upper lid portion 22 and the body portion 21 are mixed and solidified to form a welded portion 24. FIG. 5 shows a case where the outer peripheral surface 21a of the body portion 21 and the end surface 22c of the lid portion are joined by welding.

In addition, although the shape and welding method were demonstrated about the edge part of the trunk | drum 21 and the upper cover part 22, the shape of the edge part of the lower cover part 23 is made the same as the case of the upper cover part 22, and the hermetic compressor 1 is used. Can be welded to the body portion 21 in the same manner as the upper lid portion 22.

As described above, the hermetic compressor 1 according to the first embodiment includes the compression mechanism unit 5 that compresses the refrigerant, the electric motor 4 that drives the compression mechanism unit 5, and the sealed container that houses the compression mechanism unit 5 and the electric motor 4. 2, the hermetic container 2 includes a barrel portion 21 having a cylindrical shape and a lid portion having a circular lid shape and provided with a notch portion 25 on the inner peripheral side of the edge portion. (For example, the upper lid portion 22) and a welded portion 24 that joins the trunk portion 21 and the lid portion, and the cutout portion 25 is formed on the outer peripheral side of the edge portion of the trunk portion 21 and in the radial direction (direction of arrow X). And it fits so that it may oppose in an axial direction (arrow Z direction).

As a result, the circular lid-shaped lid portion is fitted and welded to the outer peripheral side of the cylindrical body portion 21, so that the deformation of the opening portion of the body portion 21 in the radial direction when the internal pressure is applied is deformed. A small amount of lid is suppressed. Therefore, the expansion of the gap between the body portion 21 and the lid portion when applying internal pressure is suppressed, and slip deformation in the elastic region occurring in the welded portion 24 is suppressed. As a result, the hermetic compressor 1 can suppress the progress of fatigue failure due to repeated operation and stop, and can increase the bonding strength between the body portion 21 and the lid portion.

Further, the cutout portion 25 has an L-shaped cross section. For this reason, the deformation of the edge portion of the body portion 21 is suppressed by the two surfaces of the notch end surface 25a and the notch inner peripheral surface 25b in the axial direction (arrow Z direction) and the radial direction (arrow X direction). Therefore, the hermetic compressor 1 can reduce the relative displacement at the edge between the body portion 21 and the lid portion, and as a result, further suppresses the slip deformation in the elastic region generated in the welded portion 24. be able to. Further, when the cross section of the notch 25 is L-shaped, the notch may be provided at a constant depth from the inner peripheral surface 22b to the outer peripheral side up to the end surface 22c. It can be easily formed by cutting or the like. Further, the shape of the outer peripheral side of the body portion 21 fitted to the notch portion 25 can be simplified.

Also, the welded portion 24 joins the outer peripheral surface 21a of the body portion 21 and the end surface 22c of the lid portion by welding. Thus, as described above, the body portion 21 and the lid portion are welded at a position where the expansion of the gap is suppressed even when the internal pressure is applied, so that slip deformation in the elastic region occurring in the welded portion 24 is suppressed. The hermetic compressor 1 can obtain the hermetic container 2 with improved fatigue life.

Further, the sealed container 2 includes lid portions (an upper lid portion 22 and a lower lid portion 23) on the upper portion and the lower portion of the trunk portion 21, respectively. From this, by making the edge part of the lower cover part 23 the same shape as the edge part of the upper cover part 22, in the upper part and lower part of the trunk | drum 21, the expansion of the clearance gap with the cover part at the time of internal pressure application is suppressed, Slip deformation in the elastic region occurring in the upper and lower welds 24 is suppressed. Therefore, fatigue life can be improved also in the airtight container 2 provided with a cover part up and down.

The refrigerant is a carbon dioxide refrigerant. From this, when the carbon dioxide refrigerant whose internal pressure is higher than that of the HFC refrigerant or the like is used, particularly the fatigue damage of the sealed container 2 is concerned, but the hermetic compressor 1 uses the carbon dioxide refrigerant. Even in this case, the sealed container 2 having an improved fatigue life can be obtained.

The embodiment of the present invention is not limited to the above embodiment, and various changes can be made. For example, FIG. 1 shows a case where the hermetic compressor 1 is a high-pressure single-stage rotary compressor, but is not particularly limited thereto. The hermetic compressor 1 may be, for example, a multistage type or an intermediate pressure type, or may adopt a different compression method such as a scroll type or a reciprocating type.

The present invention can be used in a hermetic compressor that welds the body and the lid.

1 sealed compressor, 2 sealed container, 3 pedestal, 4 motor, 5 compression mechanism, 6a terminal, 6b lead wire, 7a refrigerant suction pipe, 7b refrigerant discharge pipe, 21 barrel, 21a outer peripheral surface, 21b inner peripheral surface , 21c end surface, 22 upper lid portion, 22a outer peripheral surface, 22b inner peripheral surface, 22c end surface, 23 lower lid portion, 24 welded portion, 25 cutout portion, 25a cutout end surface, 25b cutout inner peripheral surface, 41 stator, 42 rotor, 51 crankshaft, 51a eccentric part, 51b rotary shaft, 52 cylinder, 52a compression chamber, 53 upper bearing, 54 lower bearing, 55 rollers.

Claims

In a hermetic compressor including a compression mechanism that compresses a refrigerant, an electric motor that drives the compression mechanism, and a hermetic container that houses the compression mechanism and the electric motor.
The sealed container is
A barrel having a cylindrical shape;
A lid portion having a circular lid shape and provided with a notch on the inner peripheral side of the edge;
A welded portion for joining the body portion and the lid portion,
The hermetic compressor is fitted with the cutout portion so as to oppose the outer peripheral side of the edge portion of the body portion in the radial direction and the axial direction.
The hermetic compressor according to claim 1, wherein the notch has an L shape.
3. The hermetic compressor according to claim 1, wherein the welded portion joins the outer peripheral surface of the body portion and the end surface of the lid portion by welding.
The hermetic compressor according to any one of claims 1 to 3, wherein the hermetic container is provided with the lid part at an upper part and a lower part of the body part, respectively.
The hermetic compressor according to any one of claims 1 to 4, wherein the refrigerant is a carbon dioxide refrigerant.