CN111486092A

CN111486092A - Rotary compressor and method for manufacturing rotary compressor

Info

Publication number: CN111486092A
Application number: CN202010330836.3A
Authority: CN
Inventors: 戴际强; 张奎; 桂刚; 高强
Original assignee: Guangdong Meizhi Compressor Co Ltd
Current assignee: Guangdong Meizhi Compressor Co Ltd
Priority date: 2020-04-24
Filing date: 2020-04-24
Publication date: 2020-08-04

Abstract

The invention provides a rotary compressor and a manufacturing method of the rotary compressor. The rotary compressor includes a housing, a motor assembly, and a compression mechanism. The motor assembly comprises a stator and a rotor contained in the stator, the stator is in interference fit in the shell and welded with the shell, and the outer diameter Da of the stator and the inner diameter Db of the shell satisfy the relation: Da-Db is more than 0 and less than or equal to 0.10 mm, so that the holding force of the stator in the shell is ensured, the deformation of the stator is reduced, and the efficiency of the motor is improved.

Description

Rotary compressor and method for manufacturing rotary compressor

Technical Field

The invention belongs to the technical field of compressors, and particularly relates to a rotary compressor and a manufacturing method of the rotary compressor.

Background

The rotary compressor mainly comprises a shell assembly, a motor assembly and a compression mechanism, wherein the shell assembly generally comprises a shell, an upper cover and a lower cover, the motor assembly drives the compression mechanism to rotate so as to realize refrigerant compression, and a stator of the motor assembly is fixed in the shell of the shell assembly.

Disclosure of Invention

The present invention is based on the recognition and discovery by the inventors of the following facts and problems:

in the related art, a stator of a rotary compressor is generally assembled in a shell of the compressor by a shrink-fit process, that is, an outer diameter of the stator is larger than an inner diameter of the shell, the shell is expanded by heating, then the stator is installed in the shell, and the stator is fixed in the shell after the shell is cooled, so that the stator is interference-fitted in the shell.

In the related art, in order to ensure the retention of the stator in the housing, i.e., ensure the firmness and reliability of the stator fixed in the housing, a large interference magnitude is adopted in the shrink-fit process, i.e., the difference between the outer diameter of the stator and the inner diameter of the housing is usually greater than 0.2 mm. However, through research, the inventor finds and realizes that the interference (i.e. the difference between the outer diameter of the stator and the inner diameter of the shell) is too large, so that the stress generated by the shell after cooling shrinkage is too large, and the stator deformation (motor deformation) is too large, and the motor efficiency is reduced.

It is also proposed in the related art that the stator is clearance-fitted in the housing, i.e., the outer diameter of the stator is smaller than the inner diameter of the housing, and then the stator and the housing are fixed by welding to reduce the stress deformation of the motor. However, the inventor found and realized that, for the assembly mode of the stator and the shell which are in clearance fit and welded, the contact area of the stator and the shell is small, which results in insufficient holding force of the stator in the shell, the firmness and reliability are low, especially when the displacement of the compressor is large, the inner diameter of the shell is increased, the size and weight of the motor are increased, the stator is easy to generate axial displacement and circumferential rotation relative to the shell, the reliability of the compressor is reduced, and in the case of a clearance between the stator and the shell, the welding operation is inconvenient, special tooling is required, and the cost is increased.

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

To this end, an embodiment of the present invention proposes a rotary compressor in which a holding force of a stator fixed in a casing is high, a motor deformation is small, and a motor efficiency is high.

The embodiment of the invention also provides a manufacturing method of the rotary compressor.

The rotary compressor according to the embodiment of the present invention includes: the compression mechanism comprises a shell, a motor assembly and a compression mechanism, wherein the motor assembly comprises a stator and a rotor accommodated in the stator, the stator is in interference fit in the shell and is welded with the shell, and the outer diameter Da of the stator and the inner diameter Db of the shell satisfy the relation: Da-Db is more than 0 and less than or equal to 0.10 mm.

According to the rotary compressor of the embodiment of the invention, the stator is in interference fit in the shell and is welded with the shell, and the outer diameter Da of the stator and the inner diameter Db of the shell satisfy the relation: Da-Db is more than 0 and less than or equal to 0.10 mm, so that the stator has larger holding force in the shell, the firmness and reliability of the connection between the stator and the shell are increased, the deformation of the stator is reduced, and the efficiency of the motor is high.

In some embodiments, the outer diameter Da of the stator and the inner diameter Db of the housing satisfy the relationship: Da-Db is more than or equal to 0.04 mm and less than or equal to 0.08 mm.

In some embodiments, the weld formed by welding the stator and the shell is strip-shaped.

In some embodiments, the length L b of the weld and the axial length L a of the stator satisfy the relationship 0.2 ≦ L b/L a ≦ 0.8.

In some embodiments, the included angle theta between the length direction of the welding seam and the axial direction of the stator is 0-45 degrees.

In some embodiments, the weld seam formed by welding the stator and the shell is a plurality of weld seams, and the plurality of weld seams are distributed at intervals along the circumferential direction of the shell.

In some embodiments, the stator is laser welded to the housing.

According to the manufacturing method of the rotary compressor of the embodiment of the present invention, the rotary compressor includes a housing and a motor assembly including a stator and a rotor, an outer diameter Da of the stator and an inner diameter Db of the housing satisfy a relational expression: 0 < Da-Db is less than or equal to 0.10 mm, and the method comprises the following steps: heating the housing to expand the housing to fit the stator within the housing; welding the stator to the housing.

According to the manufacturing method of the rotary compressor of the embodiment of the present invention, the housing is expanded by heating the housing to fit the stator in the housing and weld the stator and the housing, and the outer diameter Da of the stator and the inner diameter Db of the housing satisfy the relation: Da-Db is more than 0 and less than or equal to 0.10 mm, so that the stator deformation is small, the motor efficiency is high, the stator holding force is improved, and the connection reliability of the stator and the shell is improved.

In some embodiments, the welding seam formed by welding the stator and the shell is long, the welding seams are multiple and are distributed at intervals along the circumferential direction of the shell, and an included angle theta between the length direction of the welding seam and the axial direction of the stator is greater than or equal to 0 and less than or equal to 45 degrees.

In some embodiments, the welding is laser welding.

Drawings

Fig. 1 is a longitudinal sectional view schematically showing a rotary compressor according to an embodiment of the present invention.

Fig. 2 is a schematic view of a stator of a rotary compressor according to an embodiment of the present invention.

Fig. 3 is a schematic view of a weld on an outer circumferential wall surface of a casing of a rotary compressor according to an embodiment of the present invention.

Fig. 4 is another schematic view of a weld on a circumferential surface outside a casing of a rotary compressor according to an embodiment of the present invention.

Fig. 5 is still another schematic view of a weld on an outer circumferential wall surface of a casing of a rotary compressor according to an embodiment of the present invention.

Fig. 6 shows a graph S1 of a relationship between stator holding force and interference in a case where a stator is interference-fitted in a housing and the stator is welded to the housing, and a graph S2 of a relationship between stator holding force and interference in a case where a stator is interference-fitted only in the housing but not welded to the housing in the related art, according to an embodiment of the present invention.

Fig. 7 is a schematic diagram illustrating a relation S3 between the efficiency of the motor and the interference in the case where the stator is interference-fitted in the housing and welded to the housing according to the embodiment of the present invention.

Reference numerals:

the rotary compressor 1 is rotated in such a manner that,

a housing assembly 10, a weld 11, an upper cover 12, a bottom cover 13, a housing 14,

the motor assembly 20, the stator 201, the rotor 202,

and a compression mechanism 30.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

A rotary compressor 1 according to an embodiment of the present invention is described below with reference to fig. 1 to 7.

As shown in fig. 1 to 7, a rotary compressor 1 according to an embodiment of the present invention includes a shell assembly 10, a motor assembly 20, and a compression mechanism 30.

The motor assembly 20 includes a stator 201 and a rotor 202 rotatably provided within the stator 201.

As shown in fig. 1, the housing assembly 10 includes a housing 14, an upper cover 12, and a bottom cover 13. In the embodiment shown in fig. 1, the housing 14 is open at both upper and lower ends, the upper cap 12 is coupled to the top of the housing 14 to close the upper end of the housing 14, and the lower cap 13 is coupled to the bottom of the housing 14 to close the lower end of the housing 14.

The motor assembly 20 and the compression mechanism 30 are mounted within the housing 14, and the motor assembly 20 drives the compression mechanism 30 to operate.

The stator 201 of the motor assembly 20 is interference-fitted in the housing 14 and the stator 201 is welded to the housing 10, thereby fitting the stator 201 in the housing 14. For example, the stator 201 is fitted into the housing 14 by a shrink-fit process, whereby the stator is interference-fitted with the housing 14 after the housing 14 is cooled, while the stator 201 is welded with the housing 14.

According to the rotary compressor of the embodiment of the present invention, the outer diameter Da of the stator 201 and the inner diameter Db of the housing 14 satisfy the relation: Da-Db is more than 0 and less than or equal to 0.10 mm.

The inventors have found through research that, when the stator 201 is interference-fitted in the housing 14 while the stator 201 is welded to the housing 14 as shown in fig. 6, the relationship curve between the interference amount Da-Db and the holding force of the stator 201 in the housing 14 is S1, and as can be seen from fig. 6, when the interference amount Da-Db exceeds 0.1 mm, the interference amount is increased and the holding force of the stator is not substantially increased. In contrast, when the stator 201 is interference-fitted only in the housing 14 but not welded to the housing 14, the relationship curve between the interference amount Da-Db and the stator holding force of the stator 201 in the housing 14 is S2, and as can be seen from fig. 6, the interference amount is positively correlated with the stator holding force.

A curve S3 in fig. 7 shows a relationship between the motor efficiency and the interference Da-Db, and it can be seen from fig. 7 that the larger the interference Da-Db is, the lower the motor efficiency is (i.e., the larger the stator deformation is).

Through the research and discovery of the inventor, the stator 201 is in interference fit in the shell 14, the stator 201 and the shell 14 are welded, and the interference Da-Db between the stator and the shell satisfies 0 & lt Da-Db & lt 0.10 mm, so that the holding force of the stator 201 in the shell 14 can be ensured, and the motor efficiency is high. If the interference exceeds 0.1 mm, the stator holding force is not increased any more, but the motor efficiency is further decreased. If the interference is smaller than 0, in other words, the stator 201 is in clearance fit in the housing 14, that is, the stator and the housing are connected only by welding in the related art, there is a problem that the contact area of the stator and the housing is small and the holding force is insufficient.

Therefore, according to the rotary compressor of the embodiment of the present invention, the stator is interference-fitted in the housing and the stator is welded to the housing, and the outer diameter Da of the stator and the inner diameter Db of the housing satisfy the relation: Da-Db is more than 0 and less than or equal to 0.10 mm, so that the stator has larger holding force in the shell, the firmness and reliability of the stator fixed in the shell are improved, the stator deformation is reduced, and the motor efficiency is high.

As shown in fig. 6 and 7, in some embodiments, the outer diameter Da of the stator 201 and the inner diameter Db of the housing 14 satisfy the relationship: the Da-Db is more than or equal to 0.04 mm and less than or equal to 0.08 mm, so that the smaller interference magnitude plays a role in reducing the stress deformation of the stator caused by assembling and fixing the stator by the heat sleeve and avoiding the efficiency reduction of the motor, and meanwhile, stronger stator holding force can be provided. In other embodiments, the interference amount Da-Db may alternatively be 0.02 mm, 0.04 mm, 0.06 mm, 0.08 mm.

As shown in fig. 3 to 5, in some embodiments, the welding seam 11 formed by welding the stator 201 and the shell 14 is a strip shape, and when welding, the stator 201 and the shell 14 are welded from the outside of the shell 14. Preferably, the welding seam 11 formed by welding the stator 201 and the shell 14 is rectangular, the rectangular welding seam 11 is regular in shape, the welding process is easy to operate, and compared with spot welding, the welding area is large, the welding strength is improved, the stator is not easy to damage, and the pressure resistance strength of the shell cannot be reduced. It should be understood that the shape of the weld 11 is not limited to a rectangle, and may be other long shapes such as a trapezoid.

As shown in FIGS. 1 and 3, in some embodiments, the length L b of the weld 11 and the axial length L a of the stator 201 satisfy the relationship 0.2 ≦ L b/L a ≦ 0.8, whereby the weld strength may be improved.

As shown in FIG. 4, in some embodiments, the angle θ between the length direction of the weld 11 and the axial direction of the stator 201 is 0 ≦ θ ≦ 45 degrees. For example, θ is 20 degrees, 30 degrees or 40 degrees. Therefore, welding points on the surface of the shell 14 can be distributed reasonably, and welding strength is improved.

As shown in fig. 1 and 2, in some embodiments, the weld 11 formed by welding the stator 201 and the casing 14 is a plurality of welds 11, and the plurality of welds 11 are distributed at intervals along the circumferential direction of the casing 14. Therefore, the connection strength between the stator 201 and the shell 14 can be improved by using a plurality of welding points distributed in the circumferential direction, and the stress caused by welding is uniformly distributed.

As shown in FIG. 3, in some embodiments, the plurality of welds 11 are centered within the same cross-section of the housing 14. In other words, the centers of the plurality of weld beads 11 are located in the same horizontal plane.

As shown in FIG. 5, in some embodiments, the center of at least one weld 11 of the plurality of welds 11 is located within a different cross-section of the shell 14 than the center of the remaining welds 11. In other words, as shown in fig. 5, the centers of the plurality of weld beads 11 may be distributed in different horizontal planes.

As shown in fig. 1, in some embodiments, the center of the weld 11 formed by welding the stator 201 and the housing 14 is equidistant from the first end (the upper end shown in fig. 1) and the second end (the lower end shown in fig. 1) of the stator 201, in other words, the plane where the center of the weld 11 is located passes through the center of the stator 201, so that the welding stress distribution can be uniform, and the stress deformation of the stator 201 can be further reduced.

In some preferred embodiments, the stator 201 is laser welded to the housing 14. The inventor realizes that welding stator and casing through argon arc spot welding, has welding temperature height, forms local high temperature easily in the solder joint position, welds stator core through, causes the stator inefficacy, reduces the compressive strength of casing moreover easily, comparatively speaking, adopts the mode of laser welding, and laser welding temperature is relative low, and the temperature variation is very little in the stator core inslot during the welding, has avoided welding the risk of wearing.

A rotary compressor 1 according to one specific example of the present invention is described below with reference to fig. 1 to 7.

As shown in fig. 1, the rotary compressor 1 includes a housing assembly 10, a motor assembly 20, and a compression mechanism 30. The housing assembly 10 includes a housing 14, an upper cover 12 and a lower cover 13, the upper and lower ends of the housing 14 are open, the upper cover 12 is mounted on the top of the housing 14 to seal the upper end of the housing 14, the lower cover 13 is mounted on the lower portion of the housing 14 to close the lower end of the housing 14, a motor assembly 20 and a compression mechanism 30 are provided in the housing 14, and the motor assembly 20 drives the compression mechanism 30 to operate. It will be appreciated that the bottom cover 13 may also be formed integrally with the housing 14.

As shown in fig. 1, the motor assembly 20 includes a stator 201 and a rotor 202, the stator 201 is interference-fitted in the housing 14, for example, by a shrink-fit process, and an outer diameter Da of the stator 201 and an inner diameter Db of the housing 14 satisfy a relation: Da-Db is more than 0 and less than or equal to 0.10 mm, and the stator 201 is welded with the shell 14 to form rectangular welding seams 11 which are uniformly distributed at intervals along the circumferential direction of the shell 14. It should be noted that the number of weld seams 11 may be 2-10, and three weld seams 11 are shown in fig. 3, which is merely illustrative, and the number of weld seams 11 may be determined according to the size of the housing and the motor assembly.

As shown in fig. 3, the long sides of the three welds 11 extend in the axial direction of the stator 201, the centers of the three welds 11 are located on the same cross section of the casing 14, and preferably, the distance from the center of the weld 11 to the upper end of the stator 201 is equal to the distance from the center to the lower end of the stator, in other words, the horizontal height of the centers of the welds is the same with respect to one end of the stator 201. In some embodiments, as shown in FIG. 4, the weld 11 extends obliquely, and the included angle θ between the long side of the weld 11 and the axial direction of the stator 201 is 0 ≦ θ ≦ 45 degrees.

As shown in fig. 5, the centers of the four weld seams 11 are located in different cross sections of the housing 14, wherein two of the weld seams 11 are located in the same cross section of the housing 14 and the other two weld seams 11 are located in another cross section of the housing 14.

A method of manufacturing a rotary compressor according to an embodiment of the present invention is described below.

The rotary compressor comprises a shell and a motor assembly, wherein the motor assembly comprises a stator and a rotor, and the outer diameter Da of the stator and the inner diameter Db of the shell satisfy the relation: 0 < Da-Db is less than or equal to 0.10 mm, and the manufacturing method comprises the following steps:

heating the housing expands the housing to fit the stator within the housing, welding the stator to the housing. In other words, the stator is assembled in the housing by a shrink-fitting process, whereby after cooling, the stator is interference-fitted with the housing, and the housing is welded with the stator.

According to the manufacturing method of the rotary compressor of the embodiment of the invention, the stator is assembled in the shell through the shrink fit process, the stator and the shell are in over-hard fit and welded, and simultaneously the outer diameter Da of the stator and the inner diameter Db of the shell satisfy the relation: Da-Db is more than 0 and less than or equal to 0.10 mm, so that the stator has small deformation, the motor assembly efficiency is high, the stator is kept high in the shell, and the fixation firmness and reliability of the stator and the shell are high.

3-5, in some embodiments, the weld formed by welding the stator and the housing is rectangular, and the included angle theta between the length direction of the weld and the axial direction of the stator is 0-45 degrees. In some embodiments, as shown in fig. 2-5, the weld formed by welding the stator and the casing is a plurality of welds, the plurality of welds are spaced apart along the circumference of the casing, and the plurality of welds are centered within the same cross-section or different cross-sections of the casing.

In some preferred embodiments, the welding is laser welding, and the laser welding temperature is relatively low, so that the temperature change in the stator core slot is small during welding, the risk of welding through is avoided, the shell is not easy to damage, and the pressure resistance strength of the shell is improved.

In the description of the present invention, it is to be understood that the terms "center", "length", "upper", "lower", "front", "horizontal", "bottom", "inner", "outer", "axial", "circumferential", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A rotary compressor, comprising: the compression mechanism comprises a shell, a motor assembly and a compression mechanism, wherein the motor assembly comprises a stator and a rotor accommodated in the stator, the stator is in interference fit in the shell and is welded with the shell, and the outer diameter Da of the stator and the inner diameter Db of the shell satisfy the relation: Da-Db is more than 0 and less than or equal to 0.10 mm.

2. The rotary compressor of claim 1, wherein the outer diameter Da of the stator and the inner diameter Db of the housing satisfy a relation: Da-Db is more than or equal to 0.04 mm and less than or equal to 0.08 mm.

3. The rotary compressor of claim 1, wherein the weld formed by welding the stator and the shell is a bar.

4. The rotary compressor of claim 3, wherein the length L b of the weld and the axial length L a of the stator satisfy the relationship 0.2 ≦ L b/L a ≦ 0.8.

5. The rotary compressor of claim 3, wherein an angle θ between a length direction of the weld and an axial direction of the stator is 0 ° or more and 45 ° or less.

6. The rotary compressor of claim 1, wherein the stator is welded to the housing at a plurality of welds, the plurality of welds being spaced apart along a circumference of the housing.

7. The rotary compressor of any one of claims 1-6, wherein the stator is laser welded to the housing.

8. A method of manufacturing a rotary compressor, characterized in that the rotary compressor comprises a housing and a motor assembly including a stator and a rotor, an outer diameter Da of the stator and an inner diameter Db of the housing satisfying a relation: 0 < Da-Db is less than or equal to 0.10 mm, and the manufacturing method comprises the following steps:

heating the housing to expand the housing to fit the stator within the housing;

welding the stator to the housing.

9. The manufacturing method of a rotary compressor according to claim 8, wherein a weld formed by welding the stator and the housing is elongated, the weld is plural and spaced apart in a circumferential direction of the housing, and an angle θ between a length direction of the weld and an axial direction of the stator is 0 ° or more and 45 ° or less.

10. The manufacturing method of a rotary compressor according to claim 8 or 9, wherein the welding is laser welding.