Stator assembly, motor and air compressor

Abstract

The utility model provides a stator assembly, a motor and an air compressor. The stator assembly comprises a shell and a stator, wherein a stator core is assembled in the shell; the motor also comprises a transition piece which is cylindrical and is arranged between the stator iron core and the housing; the inner circumferential surface of the transition piece abuts against the outer wall of the stator core, and the outer circumferential surface of the transition piece abuts against the inner wall of the shell; the thermal expansion coefficient of the shell is set as a, the thermal expansion coefficient of the transition piece is set as b, the thermal expansion coefficient of the stator core is set as c, and a > = b > c or b > = a > c is satisfied. The transition piece is arranged between the stator iron core and the shell, so that the interference magnitude of interference assembly of the inner wall of the shell and the outer wall face of the stator iron core is reduced to the maximum extent, the hot charging process of the shell and the stator iron core can be improved to the maximum extent, the assembly precision of the stator iron core and the shell after hot charging is guaranteed, and the assembly efficiency of the stator iron core and the shell is improved. And the manufacturing cost of the high-speed motor is reduced as much as possible.

Description

[0001] This application claims the priority of a Chinese patent application with the application number 202411191738.0 and the invention title "Stator Assembly and Its Assembly Method, Motor and Air Compressor", which was filed with the Chinese Patent Office on August 28, 2024. The entire content is incorporated herein by reference. Technical Field

[0002] This application belongs to the technical field of air compressors, and particularly relates to a stator assembly, a motor, and an air compressor. Background Art

[0003] Most existing high-speed motors use aluminum housings, and the stator core of the high-speed motor is fixed to the housing by interference fit or mechanical fixing. As Figure 8 shown, it is ensured that the stator core of the motor does not become loose during the operation of the high-speed motor. However, due to the different thermal expansion coefficients of the aluminum housing and the silicon steel sheet material of the motor stator core, where the thermal expansion coefficient of aluminum is greater than that of the silicon steel sheet, in order to ensure that there is still a certain interference amount between the outer diameter of the high-speed motor stator core and the inner diameter of the housing at the highest operating temperature of the motor, a large initial interference amount is required between the stator core and the housing. In order to relatively easily complete the assembly, the aluminum housing needs to be heated to a very high temperature during the hot-fitting process. However, the excessive hot-fitting heating temperature and the large interference amount are likely to cause some irreversible deformation of the aluminum housing. As Figure 9 shown, the dotted line shows the profile of the aluminum housing before hot-fitting, which is straight, while the hot-fitting process causes the profile to deform and have a certain curvature. Utility Model Content

[0004] Therefore, this application provides a stator assembly, a motor, and an air compressor, which can solve the problem that the high temperature causes irreversible deformation of the aluminum housing during the hot-fitting process of the housing and the stator core in the prior art.

[0005] To solve the above problems, this application provides a stator assembly, including a housing and a stator core, and the stator core is assembled in the housing; it further includes:

[0006] A transition member, which is cylindrical and is arranged between the stator core and the housing; the inner circumferential surface of the transition member abuts against the outer wall of the stator core, and the outer circumferential surface abuts against the inner wall of the housing;

[0007] The thermal expansion coefficient of the housing is set as a, the thermal expansion coefficient of the transition member is set as b, and the thermal expansion coefficient of the stator core is set as c, satisfying a ≥ b > c, or b ≥ a > c.

[0008] In some embodiments,

[0009] The inner circumferential surface of the transition member is in interference fit with the outer wall of the stator core, and the outer circumferential surface of the transition member is in interference fit with the inner wall surface of the housing.

[0010] In some embodiments,

[0011] The housing has the same coefficient of thermal expansion as the transition member.

[0012] In some embodiments,

[0013] Both the housing and the transition member are made of aluminum or aluminum alloy.

[0014] In some embodiments,

[0015] The housing is provided with heat dissipation channels, and the channels extend along the circumferential direction of the housing.

[0016] In some embodiments,

[0017] The channels are formed by the open grooves provided on the inner wall surface of the housing and the outer circumferential surface of the transition member, and the openings of the grooves face the transition member.

[0018] According to another aspect of the present application, there is provided an assembly method for the stator assembly as described above, including:

[0019] Heating the transition member to a first preset interference amount and sleeving it on the outer periphery of the stator core so that after cooling, the inner circumferential surface of the transition member abuts against the outer wall surface of the stator core;

[0020] Heating the housing to a second preset interference amount and sleeving it on the outer periphery of the transition member so that after cooling, the inner wall surface of the housing abuts against the outer circumferential surface of the transition member.

[0021] In some embodiments,

[0022] Before the housing is sleeved on the outer periphery of the transition member, the outer circumferential surface of the transition member is processed so that the inner wall surface of the housing and the outer circumferential surface of the transition member are in interference fit.

[0023] According to another aspect of the present application, there is provided a motor, including the stator assembly as described above or the stator assembly obtained by the assembly method as described above.

[0024] According to another aspect of the present application, there is provided an air compressor, including the stator assembly as described above or the stator assembly obtained by the assembly method as described above, or the motor as described above.

[0025] A stator assembly provided by the present application includes a housing and a stator, and the stator core is assembled within the housing; it further includes: a transition member, which is cylindrical and disposed between the stator core and the housing; the inner circumferential surface of the transition member abuts against the outer wall of the stator core, and the outer circumferential surface abuts against the inner wall of the housing; the coefficient of thermal expansion of the housing is set as a, the coefficient of thermal expansion of the transition member is set as b, and the coefficient of thermal expansion of the stator core is set as c, satisfying a≥b>c or b≥a>c.

[0026] The present application has the following beneficial effects:

[0027] By providing a transition member between the stator core and the housing, the interference amount of the interference fit between the inner wall of the housing and the outer wall surface of the stator core is reduced to the greatest extent. At the same time, it reduces the variation of the housing size tolerance and geometric tolerance caused by the irreversible thermal deformation that may occur when the housing is heated at high temperature, and can greatly improve the hot-fitting process of the housing and the stator core, ensuring the assembly accuracy of the stator core and the housing after hot-fitting. While ensuring high assembly accuracy, it reduces the manufacturing cost of the high-speed motor as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. The drawings in the following description are only exemplary, and for those of ordinary skill in the art, without creative efforts, other implementation drawings can be obtained by extending the provided drawings.

[0029] Figure 1 It is a schematic structural diagram of the stator assembly of the embodiment of the present application;

[0030] Figure 2 It is a schematic structural diagram of the housing of the embodiment of the present application;

[0031] Figure 3 It is a schematic structural diagram of the stator core assembled with the transition member of the embodiment of the present application;

[0032] Figure 4 It is a schematic structural diagram of the stator core of the embodiment of the present application;

[0033] Figure 5 It is another schematic structural diagram of the stator assembly of the embodiment of the present application;

[0034] Figure 6 It is a third schematic structural diagram of the stator assembly of the embodiment of the present application;

[0035] Figure 7 For the embodiment of the present application Figure 6 exploded structural diagram;

[0036] Figure 8 It is a structural schematic diagram of a traditional stator assembly;

[0037] Figure 9 is Figure 8 a partially enlarged structural schematic diagram in

[0038] The reference numerals are shown as:

[0039] 1. Housing; 11. Flow channel; 12. Groove;

[0040] 2. Transition piece;

[0041] 3. Stator core. Specific embodiments

[0042] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0043] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description. Without contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, so it cannot be understood as a limitation on the protection scope of the present application; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0044] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. can be used here to describe the spatial positional relationship between a device or feature shown in the figure and other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations during use or operation in addition to the orientation depicted in the figure for the device. For example, if the device in the attached drawing is inverted, a device described as "above or over other devices or structures" will then be positioned as "below or under other devices or structures". Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations are made for the spatial relative descriptions used here.

[0045] In addition, it should be noted that the use of terms such as "first", "second" etc. to define components is merely for the convenience of differentiating the corresponding components. Without additional statements, the above terms have no special meanings, and thus should not be construed as limiting the protection scope of this application.

[0046] Referring jointly to Figures 1 to 7 As shown, according to an embodiment of the present application, a stator assembly includes a housing 1 and a stator core 3, and the stator core 3 is assembled within the housing 1; it further includes:

[0047] A transition member 2, configured as a cylinder, is disposed between the stator core 3 and the housing 1; the inner circumferential surface of the transition member 2 abuts against the outer wall of the stator core 3, and the outer circumferential surface abuts against the inner wall of the housing 1;

[0048] The coefficient of thermal expansion of the housing 1 is set as a, the coefficient of thermal expansion of the transition member 2 is set as b, and the coefficient of thermal expansion of the stator core 3 is set as c, satisfying a ≥ b > c, or b ≥ a > c.

[0049] In this application, by providing the transition member 2 between the stator core 3 and the housing 1, the interference amount of the interference fit between the inner wall of the housing 1 and the outer wall surface of the stator core 3 is minimized to the greatest extent. At the same time, the dimensional tolerance and form and position tolerance deterioration of the housing 1 caused by irreversible thermal deformation that may occur during high-temperature heating of the housing 1 are reduced, which can greatly improve the hot-fitting process of the housing 1 and the stator core 3, ensure the assembly accuracy of the stator core 3 and the housing 1 after hot-fitting, and while ensuring high assembly accuracy, the manufacturing cost of the high-speed motor is reduced as much as possible.

[0050] The transition piece 2 provided between the stator core 3 and the housing 1 has the same or similar coefficient of thermal expansion as that of the housing 1, so that the two will not be separated due to heat generation. Therefore, a very small designed interference fit or even a transition fit can be used for assembly between the two.

[0051] If the present application continues to adopt the existing common hot-fitting scheme and directly hot-fits the stator core 3 and the housing 1, the large interference fit required is greatly reduced by the transition piece 2. Moreover, the size of the transition piece 2 can be directly processed. By using the same or similar coefficient of thermal expansion between the transition piece 2 and the housing 1, it is ensured that after the stator core 3 with the transition piece 2 is installed in the housing 1, the thermal deformation of the housing 1 can be minimized, and the size and geometric tolerance of the positioning stop of the housing 1 after thermal assembly are ensured, realizing high assembly accuracy.

[0052] In some embodiments,

[0053] The inner peripheral surface of the transition piece 2 and the outer wall of the stator core 3 are in interference fit, and the outer peripheral surface of the transition piece 2 and the inner wall surface of the housing 1 are in interference fit.

[0054] The transition piece 2 is in interference fit with the adjacent stator core 3 and the housing 1, improving the connection stability between the three and avoiding safety problems during high-speed operation of the motor.

[0055] In some embodiments,

[0056] The coefficient of thermal expansion of the housing 1 is the same as that of the transition piece 2.

[0057] In the present application, it is preferably that the coefficients of thermal expansion of the housing 1 and the transition piece 2 are the same. In this way, the transition piece 2 and the housing 1 are made of the same material, with the same size and coefficient of thermal expansion upon heating, and they will not be separated due to heat generation. Therefore, a very small designed interference fit or even a transition fit can be used for assembly between the two.

[0058] In some embodiments,

[0059] Both the housing 1 and the transition piece 2 are made of aluminum or aluminum alloy.

[0060] More specifically, both the housing 1 and the transition piece 2 are made of aluminum material. The heat generated by the motor can be conducted to the housing 1 in time through the transition piece 2, and the aluminum housing 1 has good heat dissipation effect, so that the heat generated inside the housing 1 can be conducted away in time.

[0061] The above-mentioned aluminum material includes pure aluminum or aluminum alloy. Aluminum alloy materials are often used as the housing material, including but not limited to ZL101A, A356, 6061, etc.

[0062] In some embodiments,

[0063] A heat dissipation flow channel 11 is provided in the housing 1, and the flow channel 11 extends along the circumferential direction of the housing 1.

[0064] To further improve the heat dissipation effect of the housing 1, a heat dissipation flow channel 11 is provided in the housing 1 for injecting a cooling fluid in a flowing state, such as water, which can take away the heat of the housing 1.

[0065] In some embodiments,

[0066] The flow channel 11 is formed by an open groove 12 provided on the inner wall surface of the housing 1 and the outer peripheral surface of the transition member 2, and the opening of the groove 12 faces the transition member 2.

[0067] The flow channel 11 can be formed by an open groove 12 on the inner wall surface of the housing 1 in combination with the outer peripheral surface of the transition member 2, that is, the outer peripheral surface of the transition member 2 covers the opening of the groove 12; this facilitates the processing of the flow channel 11. The groove 12 with an opening can be directly processed on the inner wall surface of the housing 1 first, and then when the transition member 2 is installed, it just covers the opening.

[0068] For the above-mentioned flow channel 11, it can be spirally arranged along the axial direction of the housing 1 as shown in Figure 1 , 2 or 6, or it can be arranged to extend circumferentially as shown in Figure 5 .

[0069] According to another aspect of the present application, an assembly method of the stator assembly as described above is provided, including:

[0070] Heating the transition member 2 to a first preset interference amount and sleeving it on the outer periphery of the stator core 3, so that after cooling, the inner peripheral surface of the transition member 2 abuts against the outer wall surface of the stator core 3;

[0071] Heating the housing 1 to a second preset interference amount and sleeving it on the outer periphery of the transition member 2, so that the inner wall surface of the housing 1 after cooling abuts against the outer peripheral surface of the transition member 2.

[0072] In the stator assembly of the present application, a transition member 2 is added between the motor stator core 3 and the housing. The transition member 2 needs to be thermally assembled with the motor stator core 3 first, and then assembled with the housing 1 as a whole. It should be noted that the material of the transition member 2 should be the same as that of the housing 1 or have a similar coefficient of thermal expansion.

[0073] The transition piece 2 is a cylindrical part, which is a precision-machined part. Before the hot assembly of the transition piece 2 and the motor stator core 3, the interference amount needs to be pre-designed according to the temperature rise during the actual operation of the motor. The inner diameter dimension of the transition piece 2 and the outer diameter dimension of the motor stator core 3 are precision-machined to the pre-designed dimensional tolerance to ensure that the motor stator core 3 will not become loose from the transition piece 2 after the temperature rises during operation after the hot assembly of the motor stator core 3 and the transition piece 2.

[0074] To facilitate the assembly of the stator core 3 with the transition piece 2 sleeved thereon into the housing 1, the inner wall diameter dimension of the housing 1 is designed to be stepped, including a diameter dimension surface L1 of the hot assembly mating circle and an axial positioning diameter dimension L2, where L2 is greater than L1. The outer diameter dimension of the transition piece 2 is the same as the dimension of the hot assembly mating circle surface L1 of the housing 1 and is machined according to a small interference tolerance zone. Since the transition piece 2 and the housing 1 are made of the same material, their dimensions and thermal expansion coefficients are the same and they will not become separated due to heating. Therefore, a very small designed interference amount or even a transition fit method can be used for the assembly between the two. During the hot assembly, the non-outlet end of the motor stator core 3 with the transition piece 2 already hot-assembled is inserted into the housing 1 from the opposite side of the large-sized positioning stop of the housing 1 and axially assembled to the position of the hot assembly mating circle to complete the assembly in place.

[0075] In some embodiments,

[0076] Before the housing 1 is sleeved on the outer periphery of the transition piece 2, the outer peripheral surface of the transition piece 2 is processed so that the inner wall surface of the housing 1 and the outer peripheral surface of the transition piece 2 are in interference fit.

[0077] After the hot assembly of the transition piece 2 and the motor stator core 3, the outer diameter of the hot-assembled transition piece also needs to be precision-machined once. Since the transition piece 2 and the stator core 3 are in interference fit after the hot assembly, the transition piece 2 will be deformed and the outer diameter dimension will become larger; precision-machining the outer diameter of the transition piece 2 is for one thing to control the overall outer diameter dimension of the stator core 3 and the transition piece 2 to ensure that the interference amount with the housing 1 is within the designed range, and for another thing to ensure the coaxiality accuracy of the overall outer circle of the stator core 3 and the transition piece 2 and the stator inner hole through precision-machining, so as to ensure the high-precision fit between the stator core 3 and the housing 1.

[0078] In the structure where the flow channel 11 in the above-mentioned housing 1 is formed by the housing 1 and the transition piece 2, the flow channel 11 of the housing 1 is split into an inner part and an outer part. The inner part is the transition piece 2, and the transition piece 2 and the motor stator core 3 are still hot-fitted according to the preset interference amount. After hot-fitting, the outer surface of the transition piece 2 is secondarily precision machined according to the small interference fit tolerance, and the mating surface between the transition piece 2 and the housing 1 is a smooth surface. The outer part is the housing 1 with a complete flow channel 11 and not closed. The place where the inner wall of the housing 1 mates with the transition piece 2 is also precision machined according to the small interference fit tolerance. Then, the processed stator core 3 and the transition piece 2 as a whole are hot-fitted into the housing 1 to achieve the full enclosure of the flow channel 11, and the end of the mating part can be sealed with sealant or an "O" ring, thus achieving high assembly accuracy.

[0079] According to another aspect of the present application, there is provided a motor, including the stator assembly as described above or the stator assembly obtained by the assembly method as described above.

[0080] According to another aspect of the present application, there is provided an air compressor, including the stator assembly as described above or the stator assembly obtained by the assembly method as described above, or the motor as described above.

[0081] For the air compressor of the present application, the original high-temperature interference hot-fitting method of directly loading the high-speed motor stator core into the aluminum housing after high-temperature heating of the aluminum housing is changed to first machining the inner circle of the aluminum transition piece with the original interference dimension tolerance and hot-fitting it on the high-speed motor iron core to form a high-speed motor stator core assembly, and then assembling the stator core assembly with the housing.

[0082] The material of the transition piece is the same as that of the housing. The outer diameter of the transition piece is precision machined according to the small interference amount dimension tolerance set with the housing. The interference amount between the outer diameter of the transition piece and the aluminum housing is very small, and the high-speed motor stator assembly can be hot-fitted into the aluminum housing at a lower heating temperature, so a very small interference amount can ensure that the aluminum transition piece and the housing will not become loose, thereby reducing the irreversible deformation of the aluminum housing caused by high-interference hot-fitting and high-temperature heating.

[0083] It is easy for those skilled in the art to understand that, on the premise of no conflict, the above-mentioned various embodiments can be freely combined and superimposed.

[0084] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is only the preferred implementation manner of the present application. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present application, several improvements and variations can still be made, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A stator assembly, comprising a housing (1) and a stator core (3), wherein the stator core (3) is assembled in the housing (1); characterized in that: Also included are: The transition piece (2) is cylindrical and is disposed between the stator core (3) and the housing (1); the inner peripheral surface of the transition piece (2) abuts against the outer wall of the stator core (3), and the outer peripheral surface abuts against the inner wall of the housing (1); The thermal expansion coefficient of the housing (1) is set to a, the thermal expansion coefficient of the transition piece (2) is set to b, and the thermal expansion coefficient of the stator core (3) is set to c, satisfying a≥b>c, or b≥a>c.

2. The stator assembly according to claim 1, characterized in that: The inner circumferential surface of the transition piece (2) and the outer wall of the stator core (3) are in interference fit, and the outer circumferential surface of the transition piece (2) and the inner wall surface of the housing (1) are in interference fit.

3. The stator assembly according to claim 1 or 2, characterized in that: The thermal expansion coefficient of the shell (1) is the same as the thermal expansion coefficient of the transition piece (2).

4. The stator assembly according to claim 3, characterized in that: The shell (1) and the transition piece (2) are both made of aluminum or aluminum alloy.

5. The stator assembly according to claim 1, characterized in that: A heat dissipation channel (11) is provided in the shell (1), and the channel (11) is extended along the circumference of the shell (1).

6. The stator assembly according to claim 5, characterized in that: The flow channel (11) is formed by an open groove (12) provided on the inner wall surface of the shell (1) and the outer peripheral surface of the transition piece (2), and the groove (12) opens toward the transition piece (2).

7. A motor, characterized in that: Comprising the stator assembly according to any one of claims 1-6.

8. An air compressor, characterized in that: The invention comprises a stator assembly as claimed in any one of claims 1 to 6 or a motor as claimed in claim 7.

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