CN113708538A

CN113708538A - Motor stator fixing structure and method, motor and compressor

Info

Publication number: CN113708538A
Application number: CN202010443259.9A
Authority: CN
Inventors: 戴虎明; 汤轶群
Original assignee: Shanghai Highly Electrical Appliances Co Ltd
Current assignee: Shanghai Highly Electrical Appliances Co Ltd
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2021-11-26

Abstract

The invention discloses a motor stator fixing structure and method, a motor and a compressor. Compared with the gluing fixation of the stator in the prior art, the efficiency of the fixation by utilizing a welding mode is higher, and the operability is simpler and more convenient. And the stator and the upper shell are welded into an assembly and then are in interference fit or clearance fit with the lower shell, so that the position deviation caused by welding is offset, the position precision of the stator and the rotor is ensured, and the uniformity of the air gap between the stator and the rotor is further improved. And steps can be formed on the inner wall of the shell through machining, so that the stator can ensure certain position precision.

Description

Motor stator fixing structure and method, motor and compressor

Technical Field

The invention relates to the field of electric compressors of refrigeration equipment such as air conditioners, refrigerators and the like, in particular to a motor stator fixing structure and method, a motor and a compressor.

Background

The compressor is a driven fluid machine that raises low-pressure gas to high-pressure gas, and is the heart of a refrigeration system. The refrigerating cycle is powered by sucking low-temperature and low-pressure refrigerant gas from the air suction pipe, driving the piston to compress the refrigerant gas through the operation of the motor, and discharging high-temperature and high-pressure refrigerant gas to the exhaust pipe. The totally-enclosed refrigeration compressor is a core component of a refrigeration system, and a compression mechanism and a motor are usually arranged in a shell which is welded by fusion welding or brazing and share a main shaft, so that a shaft seal device is omitted, and the size and the weight of the whole compressor are greatly reduced. The outer surface of the shell is only welded with a suction and exhaust pipe, a process pipe and other necessary pipelines (such as a spray pipe), an input power supply wiring terminal, a compressor bracket and the like. However, since the whole compression mechanism and the motor unit are installed in a sealed casing which cannot be disassembled and are not easy to open for internal repair, the compressor is required to have high use reliability, long service life and high installation requirement on the whole refrigeration system, and the totally-enclosed structure is generally used in the small-cooling-capacity refrigeration compressor which is produced in large scale.

Referring to fig. 1, fig. 1 shows a fixing method of a motor stator in a conventional hermetic motor compressor, which adopts a method of fixing the motor stator 1 and a motor housing 2 in a shrink fit manner, and due to the shrink fit process, even if an air gap between the motor stator and the motor rotor is fixed by a fixture, the air gap between the motor stator and the motor rotor is not uniform, and the motor stator 1 is subjected to radial compressive stress, which causes iron loss and decreases motor efficiency. The existing closed type electric compressor adopts a mode of fixing a motor stator and a shell by a shrink fit, and due to the shrink fit process, the phenomenon of uneven air gaps of a stator and a rotor can also occur even if the air gaps of the stator and the rotor of the motor are fixed by a clamp, and the stator electrical steel is caused to generate stress, so that the motor efficiency is influenced.

Referring to fig. 2, a stator fixing structure of an electric compressor is also proposed in the prior art, in which a stator thermal sleeve of a motor is fixed to a housing by bonding, so that a decrease in motor efficiency caused by radial pressure applied to the stator can be reduced, stator and rotor assembly accuracy can be improved, uniformity of air gaps between the stator and the rotor can be improved, and noise can be reduced. The technical scheme in fig. 2 is used for solving the problem of the air gap precision of the stator and the rotor, but the inventor finds that the operation is complex and the production efficiency is low due to the fact that the air gap precision of the stator and the rotor is fixed by gluing in specific practical application.

Therefore, it is necessary to provide a solution that can improve the production efficiency.

It is noted that the information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The invention aims to provide a motor stator fixing structure and method, a motor and a compressor, which are used for solving the problems of complex operation and low production efficiency in the prior art.

In order to solve the technical problem, the invention provides a motor stator fixing structure, wherein a motor comprises a shell and a stator, an accommodating space is formed in the shell, and the stator is arranged in the accommodating space;

the stator is provided with a stator outer wall, the shell is provided with a shell inner wall, the shape and size of the stator outer wall are matched with those of the shell inner wall, the stator outer wall is sleeved in the shell inner wall, and the shell inner wall and the stator outer wall are connected in a welding mode and in interference fit or clearance fit;

the shell comprises an upper shell and a lower shell, and the upper shell and the stator are fixedly connected in a welding mode to form a first assembly;

the first component is connected with the lower shell through interference fit or clearance fit.

Optionally, the welding means comprises laser welding, gas shielded welding or brazing.

Optionally, the penetration of the welding means is greater than the thickness of the shell.

Optionally, the interference of the interference fit is 0mm to 0.1mm, or the clearance of the clearance fit is 0mm to 0.3 mm.

Optionally, a protruding portion is disposed on an inner wall of the lower housing, and one end of the stator is connected to the protruding portion.

Optionally, the protrusion is a step.

Optionally, the height of the step is 0.1mm-2 mm.

Optionally, the housing further has a connecting portion, the connecting portion is a connecting portion between the upper housing and the lower housing, and the upper housing and the lower housing are fixedly connected at the connecting portion by the welding method.

Based on the same invention concept, the invention also provides a motor stator fixing method, wherein the motor comprises a shell and a stator, the stator is provided with a stator outer wall, the shell is provided with a shell inner wall, the shape and size of the stator outer wall are matched with the shape and size of the shell inner wall, and the shell comprises an upper shell and a lower shell;

the motor stator fixing method comprises the following steps:

fixedly connecting the upper shell and the stator by using a welding mode to form a first assembly;

the first component and the lower housing are connected by interference fit or clearance fit.

Optionally, the method further comprises the following steps:

the upper shell and the lower shell are fixedly connected at the connecting part in a welding mode;

wherein, the connecting part is the connecting part of the upper shell and the lower shell.

Based on the same inventive concept, the invention also provides a motor, which comprises the motor stator fixing structure or the motor stator fixing method.

Based on the same inventive concept, the invention also provides a compressor comprising the motor.

Compared with the prior art, the invention has the following beneficial effects:

1. the motor stator fixing structure provided by the invention has the advantages that the stator and the shell are fixed by welding, the motor efficiency reduction caused by the stress of the stator can be reduced, the stator and rotor assembly precision is improved, the uniformity of the stator and rotor air gap is improved, and the noise is reduced. With the fixed of gluing of stator among the prior art, utilize the fixed efficiency of welding mode higher, the operability is more simple and convenient. And the stator and the upper shell are welded into an assembly and then are in interference fit or clearance fit with the lower shell, so that the position deviation caused by welding is offset, the position precision of the stator and the rotor is ensured, and the uniformity of the air gap between the stator and the rotor is further improved.

2. And steps can be formed on the inner wall of the shell through machining, so that the stator can ensure certain position precision.

3. The joint of the upper shell and the lower shell is fixedly connected in a welding mode, so that the sealing performance of a subsequently assembled motor or compressor can be guaranteed.

The motor stator fixing method, the motor and the compressor provided by the invention belong to the same invention concept with the motor stator fixing structure, so that the motor stator fixing structure has the same beneficial effects.

Drawings

Fig. 1 is a schematic view illustrating a fixing manner of a motor stator in a hermetic type electric compressor in the related art;

FIG. 2 is a schematic view of a stator fixing structure of a motor-driven compressor in the prior art;

fig. 3 is a schematic diagram of an internal structure of a first component in a stator fixing structure of a motor according to an embodiment of the present invention;

fig. 4 is a schematic internal structural diagram of a stator fixing structure of a motor according to an embodiment of the present invention;

fig. 5 is a schematic flow chart of a method for fixing a stator of an electric motor according to another embodiment of the present invention;

wherein, in fig. 1: 1-motor stator, 2-motor shell;

in fig. 3 and 4: 10-shell, 11-upper shell, 12-lower shell, 100-shell inner wall, 20-stator, 200-stator outer wall, 30-lug boss.

Detailed Description

The following describes in more detail embodiments of the present invention with reference to the schematic drawings. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "left", "right", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific 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 one or more of that feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

Referring to fig. 3 and 4, the present invention provides a stator 20 fixing structure of a motor, the motor includes a housing 10 and a stator 20, an accommodating space is formed in the housing 10, and the stator 20 is disposed in the accommodating space. Stator 20 has a stator outer wall 200, casing 10 has an shells inner wall 100, the shape size of stator outer wall 200 with the shape size of shells inner wall 100 cooperatees, stator outer wall 200 cover is established in shells inner wall 100, shells inner wall 100 with connect through welding mode and interference fit or clearance fit between stator outer wall 200. The housing 10 includes an upper housing 11 and a lower housing 12, wherein the upper housing 11 and the stator 20 are fixedly connected by welding to form a first assembly. The first component and the lower housing 12 are connected by interference fit or clearance fit.

Compared with the prior art, the fixing structure of the motor stator 20 provided by the invention has the advantages that the stator 20 and the shell 10 are fixed in a welding mode, the motor efficiency reduction caused by the stress of the stator 20 can be reduced, the stator and rotor assembly precision is improved, the uniformity of the stator and rotor air gaps is improved, and the noise is reduced. With the fixed glueing of stator 20 among the prior art, utilize the fixed efficiency of welding mode higher, the operability is more simple and convenient. In addition, the stator 20 and the upper housing 11 are welded to form an assembly and then are in interference fit or clearance fit with the lower housing 12, so that the position deviation caused by welding is offset, the position accuracy of the stator 20 and the rotor is ensured, and the uniformity of the air gap between the stator and the rotor is further improved.

In a specific practice, the upper housing 11 and the stator 20 are fixedly connected by welding, please refer to fig. 3, at this time, the first assembly is formed after the upper housing 11 and the stator 20 are welded, and then the first assembly is cold-pressed onto the lower housing 12 having a higher position accuracy with respect to the rotor by interference fit or clearance fit, please refer to fig. 4. Therefore, the position accuracy of the stator and the rotor can be further ensured, and the uniformity of the air gap between the stator and the rotor can be further improved.

Preferably, the welding method may use laser welding, and it should be noted that, in the technical solution of the embodiment of the present invention, no additional process is added for fixing the stator 20, and when the upper shell 11 is welded, the welding method uses laser welding, and the laser welding has the advantages of large penetration depth and small heat, and can simultaneously fix the upper shell 11 and the stator 20 together. The laser welding is fusion welding. Fusion welding is a welding method in which metals at a joint are melted by high temperature or the like during welding, and a strong welded joint can be formed. Because the welded workpieces are closely attached together, under the action of a temperature field, gravity and the like, no pressure is applied, and molten liquid melted by the two workpieces can be mixed. After the temperature is reduced, the melting part is condensed, and the two workpieces are firmly welded together, thus completing the welding method. A heat affected zone is created in the weld area due to the high temperature phase transformation process inherent in the welding process. It is understood that in other embodiments, other types of welding manners may be selected, for example, arc welding, gas shielded welding, brazing, electroslag welding, electron beam welding, or plasma welding may also be selected, and many other types of welding manners are available, which are not described herein in detail.

Further, the penetration depth of the laser welding is larger than the thickness of the housing 10, and by setting the penetration depth of the laser welding to be larger than the thickness of the housing 10, it is further ensured that the housing 10 and the stator 20 are fixed together at the same time.

The stator 20 is sleeved in the housing 10 and is fixedly connected to the inner wall 100 of the housing. The shape and size of the inner wall 100 of the housing and the shape and size of the outer wall 200 of the stator are matched, that is, the shape and size of the outer surface of the stator 20 are matched with the shape and size of the inner surface of the housing 10, so that when the stator 20 is sleeved on the inner wall of the housing 10, a stable clearance fit or an interference fit with a proper interference magnitude can be formed between the outer surface of the stator 20 and the inner surface of the housing 10. In the embodiment of the present invention, when the stator 20 is disposed in the housing 10, if a clearance fit is used, the clearance between the stator outer wall 200 and the housing inner wall 100 is 0mm to 0.3mm, and preferably 0.3 mm; if an interference fit is used, the interference between the stator outer wall 200 and the housing inner wall 100 is 0mm to 0.1mm, and preferably 0.1 mm. Under better dimensional accuracy, when the circumferential consistency after welding and fixing can be ensured, the assembly accuracy of the stator and the rotor can be improved, and the uniformity of the air gap between the stator 20 and the rotor is improved. It should be noted that, in the implementation of the present invention, the clearance between the stator outer wall 200 and the housing inner wall 100 actually refers to a clearance between the outer surface of the stator 20 in the first assembly and the lower housing 12, and similarly, the interference between the stator outer wall 200 and the housing inner wall 100 refers to the interference between the outer surface of the stator 20 in the first assembly and the lower housing 12.

In the embodiment of the present invention, the inner casing wall 100 and the outer stator wall 200 are connected by welding and interference fit or clearance fit. And the welding method adopted may be laser welding, so that the fixing strength between the stator 20 and the housing 10 satisfies: greater than 1KN in each direction, i.e. greater than 1KN in the radial direction, greater than 1KN axially downward, and greater than 1KN axially upward. Because the compressor mounting mode is vertical, and the main atress direction of motor stator 20 is the gravity direction when the installation, therefore radial fixation can adopt the welding mode for stator 20 surface does not produce radial compressive stress, preferred welding mode selects for use laser welding in order to guarantee stator 20 with the fixed intensity between the casing 10 all is greater than 1KN in all directions.

In addition, in the embodiment of the present invention, the material of the stator 20 is preferably electrical steel, which is also called silicon steel sheet, and is also called silicon plating, which is a ferrosilicon soft magnetic alloy with very low carbon content, and generally contains 0.5 to 4.5% of silicon. The addition of silicon can improve the resistivity and the maximum magnetic conductivity of iron, and reduce the coercive force, the iron core loss (iron loss) and the magnetic aging. The electrical steel is an important soft magnetic alloy indispensable to the power, electronic and military industries, is also a metal functional material with the largest yield, and is mainly used as iron cores of various motors, generators and transformers. The material of the motor shell 10 is preferably carbon steel, the carbon steel is iron-carbon alloy with carbon content of 0.0218% -2.11%, also called carbon steel, and generally contains a small amount of silicon, manganese, sulfur and phosphorus, and generally the carbon content in the carbon steel is higher, the hardness is higher, and the strength is higher. Preferably, the material of the shell 10 is carbon steel, and the carbon steel is iron-carbon alloy with carbon content of 0.0218% -2.11%. Also called carbon steel. Generally, the catalyst also contains small amounts of silicon, manganese, sulfur and phosphorus. Generally, the higher the carbon content in the carbon steel, the higher the hardness and the strength, but the lower the plasticity. It can be understood by those skilled in the art that the electrical steel and the carbon steel are of various types in different grades, and the types are selected according to actual needs in specific implementation, which is not described herein.

Referring to fig. 3 and 4, in the embodiment of the present invention, it is preferable that a protruding portion 30 is disposed on an inner wall of the lower housing 12, and one end of the stator 20 is connected to the protruding portion 30. And preferably the raised portion 30 circles around the inner wall of the lower housing 12. When the stator 20 is disposed in the housing 10, one end of the stator 20 is connected to the protrusion 30, that is, when the first component is connected to the lower housing 12, one end of the stator 20 is disposed on the protrusion 30, thereby fixing the position of the stator 20 in the axial direction. In the embodiment of the present invention, it is preferable that the protrusion 30 is a step, a snap spring, or a stopper.

When the protrusion 30 is a step, the protrusion 30 and the lower case 12 are integrally formed. The integral molding in the present invention means that the lower case 12 itself is directly formed or formed by processing without installing or providing other components on the lower case 12. When the protrusion 30 is provided as a step, it may be preferably implemented because it has an advantage in that it is not required to additionally mount or provide other components on the lower case 12.

Referring to fig. 3 and 4, in the embodiment of the present invention, the inner diameter of the lower housing 12 of the motor is preferably stepped by machining. The step provides axial retention of the motor stator 20 when the motor stator 20 is installed in the lower housing 12. The height of the step is preferably 0.1mm-2 mm.

In other embodiments, the protrusion 30 may be a snap spring, which may be fixedly connected to the inner wall of the lower housing 12 through a slot or directly. The clamp spring, which can be also called a retainer ring or a retaining ring, belongs to one type of fastener, is arranged in a shaft groove or a hole groove of a machine or equipment, and plays a role in preventing parts on a shaft or a hole from moving axially. It is understood that in other embodiments, the protrusion 30 may also be a stop, welded or otherwise fixed to the inner wall of the lower housing 12, to stop the axial movement of the stator 20 of the motor.

Preferably, referring to fig. 4, as can be seen from the above analysis, the housing 10 includes an upper housing 11 and a lower housing 12, and in addition, the housing 10 further has a connecting portion, the connecting portion is a connecting portion of the upper housing 11 and the lower housing 12, and after the first component and the lower housing are in interference fit or clearance fit, in order to ensure the sealing performance of the first component, the upper housing 11 and the lower housing 12 may be fixedly connected at the connecting portion by the welding method. The junction of the upper case 11 and the lower case 12 is preferably fused together by laser welding. The efficiency of utilizing the welding mode to fix is higher, and the operability is more simple and convenient. It should be noted that the penetration depth at this time may not necessarily be larger than the thickness of the shell, as long as the upper shell 11 and the lower shell 12 are ensured to be connected in a sealing manner.

Based on the same inventive concept, another embodiment of the present invention provides a method for fixing a stator 20 of a motor, the motor includes a housing 10 and the stator 20, the stator 20 has a stator outer wall 200, the housing 10 has a housing inner wall 100, the stator outer wall 200 has a shape and size matching with the shape and size of the housing inner wall 100, and the housing 10 includes an upper housing 11 and a lower housing 12. Referring to fig. 5, the method for fixing the stator 20 of the motor includes the following steps:

s1: fixedly connecting the upper shell 11 and the stator 20 by welding to form a first assembly;

s2: the first component and the lower housing 12 are connected by interference fit or clearance fit.

According to the method for fixing the motor stator 20, the stator 20 and the shell 10 are fixed in a welding mode, so that the motor efficiency reduction caused by the stress of the stator 20 can be reduced, the stator and rotor assembly precision is improved, the uniformity of the stator and rotor air gaps is improved, and the noise is reduced. With the fixed glueing of stator 20 among the prior art, utilize the fixed efficiency of welding mode higher, the operability is more simple and convenient. In addition, the stator 20 and the upper housing 11 are welded to form an assembly and then are in interference fit or clearance fit with the lower housing 12, so that the position deviation caused by welding is offset, the position accuracy of the stator 20 and the rotor is ensured, and the uniformity of the air gap between the stator and the rotor is further improved.

Preferably, the method further comprises the following steps:

the upper shell 11 and the lower shell 12 are fixedly connected at the connecting part by the welding mode;

wherein the connecting portion is a connecting portion between the upper housing 11 and the lower housing 12.

The upper shell 11 and the lower shell 12 are hermetically connected by welding, and finally a closed motor or a compressor can be formed.

Based on the same inventive concept, another embodiment of the present invention provides an electric machine, including the electric machine stator fixing structure or the electric machine stator fixing method described in any one of the above feature descriptions.

Based on the same inventive concept, the invention further provides a compressor, which comprises the motor.

In summary, the motor stator fixing structure provided by the invention fixes the stator and the shell by welding, so that the motor efficiency reduction caused by the stress of the stator can be reduced, the stator and rotor assembly precision is improved, the uniformity of the stator and rotor air gap is improved, and the noise is reduced. With the fixed of gluing of stator among the prior art, utilize the fixed efficiency of welding mode higher, the operability is more simple and convenient. And the stator and the upper shell are welded into an assembly and then are in interference fit or clearance fit with the lower shell, so that the position deviation caused by welding is offset, the position precision of the stator and the rotor is ensured, and the uniformity of the air gap between the stator and the rotor is further improved.

And steps can be formed on the inner wall of the shell through machining, so that the stator can ensure certain position precision.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example" or "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. And the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments. Furthermore, various embodiments or examples described in this specification can be combined and combined by those skilled in the art.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any way. It will be understood by those skilled in the art that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A motor stator fixing structure is characterized in that a motor comprises a shell and a stator, wherein an accommodating space is formed in the shell, and the stator is arranged in the accommodating space;

2. The stator fixing structure of the motor according to claim 1, wherein the welding means includes laser welding, gas-shielded welding or brazing.

3. The stator fixing structure of the motor according to claim 1, wherein the welding has a penetration depth larger than a thickness of the case.

4. The stator fixing structure of the motor according to claim 1, wherein the interference of the interference fit is 0mm to 0.1mm, or the clearance of the clearance fit is 0mm to 0.3 mm.

5. The stator fixing structure of the motor according to claim 1, wherein a protrusion is provided on an inner wall of the lower case, and one end of the stator is coupled to the protrusion.

6. The stator fixing structure of the motor according to claim 5, wherein the protrusion is a step.

7. The stator fixing structure of the motor according to claim 6, wherein the step has a height of 0.1mm to 2 mm.

8. The stator fixing structure of the motor according to claim 1, wherein the housing further has a connecting portion, the connecting portion is a connecting portion between the upper housing and the lower housing, and the upper housing and the lower housing are fixedly connected at the connecting portion by the welding method.

9. A motor stator fixing method is characterized in that a motor comprises a shell and a stator, wherein the stator is provided with a stator outer wall, the shell is provided with a shell inner wall, the shape and size of the stator outer wall are matched with the shape and size of the shell inner wall, and the shell comprises an upper shell and a lower shell;

the motor stator fixing method comprises the following steps:

10. The method of fixing a stator of an electric machine according to claim 9, further comprising the steps of:

11. An electric machine comprising an electric machine stator fixing structure according to any one of claims 1 to 8 or using an electric machine stator fixing method according to any one of claims 9 and 10.

12. A compressor, characterized by comprising an electric machine according to claim 11.