Rotor assembly and compressor

Abstract

A rotor assembly (30, 30A, 30B, 30C) and a compressor (1). The rotor assembly (30, 30A, 30B, 30C) comprises a rotor shaft (100, 100A, 100B, 100C), a rotor (200), a balancing block (300), and a connecting member (400); the rotor shaft (100, 100A, 100B, 100C) extends through the rotor (200) and the balancing block (300); the connecting member (400) connects the balancing block (300) and the rotor (200) such that the balancing block (300) and the rotor (200) are fixed relative to each other; the rotor shaft (100, 100A, 100B, 100C) comprises a first section (110) having a first outer diameter and a second section (120) having a second outer diameter; the first outer diameter is greater than the second outer diameter, thereby forming a step surface (130, 130A, 130B, 130C) between the first section (110) and the second section (120); and the step surface (130, 130A, 130B, 130C) is configured to be able to push the balancing block (300) towards the rotor (200).

Description

Rotor assembly and compressor

[0001] This application claims priority to the following Chinese patent application: Chinese patent application with application number 202311529044.9 submitted to the China Patent Office on November 16, 2023, and invention name “Rotor Assembly and Compressor”. The entire contents of the above patent application are incorporated into this application by reference. Technical Field

[0002] The present disclosure relates to a rotor assembly and a compressor including the rotor assembly. Background Art

[0003] The contents in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0004] A compressor (e.g., a scroll compressor) typically drives a compression member to move through a rotor assembly, thereby compressing a working fluid. In order to balance the resulting unbalance and reduce vibration or noise, a balancing weight is typically installed on the rotor to provide a counter centrifugal force.

[0005] During compressor operation, the balancing weight rotates with the rotor, generating centrifugal force. Large balancing weights generate significant centrifugal force and bending moment (especially at high compressor speeds). These forces and bending moments act on the connectors securing the balancing weight to the rotor, causing fatigue wear and tear. This can lead to loosening of the fixings between the balancing weight and the rotor, or even separation of the balancing weight from the rotor.

[0006] Therefore, there is a need to provide an improved rotor structure and compressor. Summary of the Invention

[0007] One object of one or more embodiments of the present disclosure is to improve the fatigue strength of a rotor assembly and extend the service life of the rotor assembly.

[0008] Another object of one or more embodiments of the present disclosure is to achieve precise positioning of components in the axial direction of the rotor shaft.

[0009] Yet another object of one or more embodiments of the present disclosure is to reduce machining and assembly costs of a rotor assembly.

[0010] According to one aspect of the present disclosure, a rotor assembly is provided, comprising a rotor shaft, a rotor, a balancing weight, and a connector. The rotor shaft extends through the rotor and the balancing weight, and the connector connects the balancing weight and the rotor to secure the balancing weight and the rotor relative to each other. The rotor shaft comprises a first section having a first outer diameter and a second section having a second outer diameter, wherein the first outer diameter is greater than the second outer diameter, thereby forming a step surface between the first section and the second section. The step surface is configured to push the balancing weight in a direction toward the rotor.

[0011] According to one aspect of the present disclosure, the rotor shaft includes a shaft body and a flange protruding from the shaft body, the flange forming the first section having the first outer diameter, and the shaft body forming the second section having the second outer diameter.

[0012] According to one aspect of the present disclosure, a retaining ring is provided between the step surface and the balancing weight so that the step surface pushes the balancing weight via the retaining ring, and an outer diameter of the retaining ring is greater than the first outer diameter.

[0013] According to one aspect of the present disclosure, the rotor shaft body includes a first shaft body segment forming the first segment having the first outer diameter and a second shaft body segment forming the second segment having the second outer diameter.

[0014] According to one aspect of the present disclosure, the first section and the shaft body of the rotor shaft are separate structures, and the first section is fixedly connected to the shaft body.

[0015] According to one aspect of the present disclosure, the step surface is formed as a flat first annular surface, and the balancing weight is formed with a flat second annular surface in contact with the first annular surface.

[0016] According to one aspect of the present disclosure, the connecting member includes a head and a connecting body extending from the head, the head abuts against an end surface of the balancing weight away from the rotor, and the connecting body extends through the balancing weight and the rotor.

[0017] According to one aspect of the present disclosure, the connecting member is a rivet.

[0018] According to one aspect of the present disclosure, the balancing weights pressed by the step surface are provided on both sides of the rotor in the axial direction.

[0019] According to one aspect of the present disclosure, the balancing weight pushed by the step surface is provided on a first side of the rotor in the axial direction as a first balancing weight, and a second balancing weight configured not to be pushed is provided on a second side of the rotor in the axial direction.

[0020] According to one aspect of the present disclosure, each of the first and second balancing weights has a base plate abutting against the rotor and a counterweight portion asymmetrically arranged on the base plate, and the base plate of the first balancing weight is configured to have an inner diameter smaller than an inner diameter of the base plate of the second balancing weight so as to be suitable for being pushed by the step surface.

[0021] According to another aspect of the present disclosure, a compressor including the above rotor assembly is provided.

[0022] In the rotor assembly disclosed herein, the rotor shaft bears some of the centrifugal force and bending moment generated by the rotation of the eccentrically arranged balancing weights, thereby preventing fatigue wear and fracture of the connecting components, improving the fatigue strength of the rotor assembly, and extending its service life. Furthermore, by utilizing the stepped surface of the rotor shaft to mate with the balancing weights, the axial position of the balancing weights and rotor can be precisely determined, facilitating compressor assembly and operation.

[0023] From the detailed description below, other features, advantages and application areas of the present disclosure will become more clear.It should be understood that these detailed descriptions and specific examples, although showing preferred embodiments of the present disclosure, are intended for illustrative purposes only and are not intended to limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The features and advantages of one or more embodiments of the present disclosure will become more readily understood through the following description with reference to the accompanying drawings, in which:

[0025] FIG1 is a cross-sectional view showing a compressor according to a first embodiment of the present disclosure;

[0026] 2a and 2b are exploded perspective views showing a rotor assembly according to a first embodiment of the present disclosure;

[0027] 3 is a cross-sectional view showing a rotor assembly according to a first embodiment of the present disclosure;

[0028] FIG4 is a perspective view showing a rotor assembly in an assembled state according to a first embodiment of the present disclosure;

[0029] 5 is a cross-sectional view showing a rotor assembly according to a second embodiment of the present disclosure;

[0030] FIG6 is a cross-sectional view showing a rotor assembly according to a third embodiment of the present disclosure; and

[0031] FIG. 7 is a cross-sectional view illustrating a rotor assembly according to a fourth embodiment of the present disclosure. DETAILED DESCRIPTION

[0032] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0033] Exemplary embodiments are provided so that this disclosure will be exhaustive and will more fully convey the scope to those skilled in the art. Many specific details, such as examples of specific components, devices, and methods, are described to provide a thorough understanding of the various embodiments of the present disclosure. It will be clear to those skilled in the art that specific details need not be employed, and that the exemplary embodiments can be implemented in many different forms and should not be construed as limiting the scope of the present disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0034] First, the overall structure and operating principle of a compressor (scroll compressor) will be described with reference to Figure 1. As shown in Figure 1, compressor 1 includes a housing 10, a top cover disposed at one end of housing 10, a bottom cover disposed at the other end of housing 10, and a partition 12 disposed between the top cover and housing 10 to divide the compressor's interior into a high-pressure side and a low-pressure side. The space between partition 12 and the top cover constitutes the high-pressure side, while the space between partition 12, housing 10, and bottom cover constitutes the low-pressure side. Housing 10 houses a motor, which includes a stator 20 and a rotor. It should be noted that, in this document, the assembly consisting of the motor's rotor and other components, such as the rotor shaft (described below), is referred to as the rotor assembly 30. Rotor assembly 30 includes a rotor shaft 100 to drive the compression mechanism consisting of a fixed scroll 50 and an orbiting scroll 60. The orbiting scroll 60 includes an orbiting scroll end plate 62, spiral orbiting scroll blades 64 formed on one side of the orbiting scroll end plate, and a hub 66 formed on the other side of the orbiting scroll end plate. The fixed scroll 50 includes a fixed scroll end plate 52, spiral fixed scroll blades 54 formed on one side of the fixed scroll end plate, and an exhaust port formed approximately in the center of the fixed scroll end plate. A series of compression chambers are formed between the fixed scroll blades 54 of the fixed scroll 50 and the orbiting scroll blades 64 of the orbiting scroll 60, the volume of which gradually decreases as the volume moves from the radial outside to the radial inside.

[0035] One end of the rotor shaft 100 is supported by the main bearing seat 40. An eccentric crank pin 112 is provided at one end of the rotor shaft, and an unloading bushing is provided between the eccentric crank pin 112 and the hub 66 of the movable scroll 60. The unloading bushing can be provided on the inner side of the hub, and the drive bearing can be provided between the hub and the unloading bushing and fixed to the inner wall surface of the hub. When the motor is started, the movable scroll 60 is driven by the rotor assembly to rotate relative to the fixed scroll 50 (that is, the central axis of the movable scroll 60 moves around the central axis of the fixed scroll 50, but the movable scroll 60 itself does not rotate around its own central axis) to achieve fluid compression. The fluid compressed by the fixed scroll 50 and the movable scroll 60 is discharged to the high-pressure side through the exhaust port.

[0036] In order to achieve fluid compression, an effective axial seal is required between the fixed scroll 50 and the movable scroll 60. Specifically, an axial seal is required between the top of the fixed scroll blade of the fixed scroll 50 and the movable scroll end plate 62 of the movable scroll 60, as well as between the top of the movable scroll blade of the movable scroll 60 and the fixed scroll end plate 52. Usually, a back pressure chamber is provided on the side of the fixed scroll end plate 52 opposite to the fixed scroll blade 54. The back pressure chamber is connected to the medium pressure chamber fluid through an axially extending through hole (not shown) formed in the end plate to form a force that presses the fixed scroll 50 toward the movable scroll 60. At the same time, the opposite side of the movable scroll 60 is supported / thrusted by the thrust plate against the movable scroll end plate 62, so the fixed scroll 50 and the movable scroll component 60 can be effectively pressed together by the back pressure chamber and the thrust plate.

[0037] The following describes the lubrication process for various components in the compressor. In the example of a vertical compressor shown in Figure 1, lubricant is stored at the bottom of the compressor housing. Accordingly, a channel extending generally along its axial direction is formed in the rotor shaft 100: a center hole 114 formed at the lower end of the rotor shaft 100 and an eccentric hole 116 extending upward from the center hole 114 to the end face of the eccentric crank pin 112. The end of the center hole 114 can be immersed in the lubricant at the bottom of the compressor housing or supplied with lubricant in other ways. During operation of the compressor, lubricant is supplied to one end of the center hole by a lubricant supply device. Lubricant entering the center hole 114 is pumped or flung into the eccentric hole 116 by centrifugal force during the rotation of the rotor shaft 100, and flows upward along the eccentric hole 116 until it reaches the end face of the eccentric crank pin 112. The lubricant discharged from the end surface of the eccentric crank pin 112 flows downward along the gap between the unloading bushing and the eccentric crank pin 112 and the gap between the unloading bushing and the hub, and reaches the recessed portion of the main bearing seat 40. A portion of the lubricant collected in the recessed portion flows downward through the main bearing 40, while a portion of the lubricant is stirred by the hub and moves upward to the underside of the end plate of the orbiting scroll. As the orbiting scroll rotates in translation, the lubricant spreads over the thrust surface between the orbiting scroll and the main bearing seat.

[0038] The working process and various functions of the compressor 1 are realized by the rotor of the motor driving the rotor shaft 100 to rotate. Specifically, the stator 20 of the motor is fixedly connected to the housing 10, and the rotor 200 of the rotor assembly 30 is fixedly connected to the rotor shaft 100. When the motor is started, the rotor 200 of the rotor assembly 30 rotates, thereby driving the rotor shaft 100 of the rotor assembly 30 to rotate, and then the rotor shaft 100 drives the compression mechanism to compress the working fluid. At the same time, as described above, lubrication of each component is achieved through the lubrication mechanism to ensure the normal operation of each component. During the operation of the compressor 1, the centrifugal force or centrifugal torque generated by the rotation of the eccentric component (such as the movable vortex) will cause vibration of the compressor. Therefore, usually, a balancing block is set on the rotating component (such as the rotor assembly) to provide a reverse centrifugal force or centrifugal torque to balance the imbalance generated by the eccentric component.

[0039] The following describes a rotor assembly according to a first embodiment of the present disclosure in detail with reference to Figures 2a to 4. As shown in Figures 2a and 2b, the rotor assembly 30 includes a rotor shaft 100, a rotor 200, a balancing weight 300, and a connector 400. Referring to Figure 3, the rotor shaft 100 may extend through the rotor 200 and the balancing weight 300. The balancing weight 300 and the rotor 200 may be secured to each other via the connector 400 extending therethrough. The center of mass of the balancing weight 300 may be eccentrically disposed relative to the center of rotation of the rotor assembly 30.

[0040] During the operation of the compressor, the balancing weight 300 rotates with the rotor 200, and the eccentrically arranged balancing weight will generate centrifugal force. For the balancing weight 300 with a larger mass, it will generate very large centrifugal force and bending moment when rotating at high speed. This very large centrifugal force and bending moment causes the balancing weight 300 to tend to flip away from the rotor 200, so the connector 400 needs to overcome the centrifugal force and bending moment to keep the balancing weight 300 fixed to the rotor 200. During the operation of the compressor, the connector 400 is subjected to this very large force and bending moment for a long time, making it prone to fatigue wear, and causing the fixed connection between the balancing weight 300 and the rotor 200 to loosen, or even fatigue fracture, causing the balancing weight 300 to detach from the rotor 200, thereby shortening the service life of the rotor assembly.

[0041] In some compressors, screw connectors are used to fix the balancing weight and the rotor. However, this solution requires machining threads at the corresponding positions of the balancing weight and applying thread anti-loosening glue. In addition, the screw assembly process requires more time and manpower than the rivet assembly process, which makes the processing and assembly processes more complicated and increases the processing and assembly costs.

[0042] To overcome the above problems, the inventors of this application have proposed an improved rotor assembly, which will be described below in conjunction with specific embodiments.

[0043] 3 , the balancing weight 300 may include an upper balancing weight 310 (corresponding to the first balancing weight of the present application) and a lower balancing weight 320 (corresponding to the second balancing weight of the present application) arranged at both ends of the rotor 200 along the axial direction of the rotor assembly 30 .

[0044] The rotor shaft 100 may include a first section 110 having a first outer diameter and a second section 120 having a second outer diameter, wherein the first outer diameter may be greater than the second outer diameter, thereby forming a step surface 130 between the first section 110 and the second section 120. The step surface 130 may abut against the upper balancing weight 310 to apply a compressive force to the upper balancing weight 310 when the rotor shaft 100 rotates, thereby holding the upper balancing weight 310 against the rotor 200. In the embodiment shown in FIG3 , the rotor shaft 100 may include a shaft body and a flange protruding from the shaft body, the flange may form the first section 110 having the first outer diameter, and the shaft body may form the second section 120 having the second outer diameter.

[0045] As shown in FIG3 , the step surface 130 can preferably be formed as a flat first annular surface, and the upper balancing weight 310 can be formed with a flat second annular surface 316. When the flat step surface 130 and the flat second annular surface 316 contact each other, perfect planar contact can be achieved with contact at all points, so that the step surface 130 can more stably support the upper balancing weight 310.

[0046] 3 , the upper balancing weight 310 may include a bottom plate (annular bottom plate) 312 that abuts the rotor 200 and a counterweight portion 314 eccentrically / asymmetrically arranged on the bottom plate. Similarly, the lower balancing weight 320 may also include a bottom plate (annular bottom plate) 322 that abuts the rotor 200 and a counterweight portion 324 eccentrically / asymmetrically arranged on the bottom plate. Preferably, the bottom plate 312 of the upper balancing weight 310 may extend inward toward the rotor shaft 100, such that the bottom plate 312 may have a larger area than the bottom plate 322. In other words, the bottom plate 312 of the upper balancing weight 310 is configured to have an inner diameter smaller than the inner diameter of the bottom plate 322 of the lower balancing weight, thereby being adapted to be pressed by the step surface. The upper surface of the bottom plate 312 of the upper balancing weight forms a second annular surface 316. The increased area of ​​the bottom plate 312 can increase the contact area between the step surface 130 and the second annular surface 316, thereby further enabling the step surface 130 to stably support the upper balancing weight 310. Furthermore, in the present application, the bottom plate is configured to have a relatively small axial thickness. For example, the axial thickness of the bottom plate is between 10% and 20% of the overall axial thickness of the balancing weight.

[0047] 3 and 4 , the connector 400 may include a head 410 and a connecting body 420 extending from the head 410. The head 410 may abut the end surface of the upper balancing weight 310 facing away from the rotor 200 (i.e., the upper end surface of the upper balancing weight 310), and the connecting body 420 may extend through the balancing weight 310, the rotor 200, and the lower balancing weight 320. The connector 400 may be, for example, a rivet. Using rivets to secure the balancing weight 310, the rotor 200, and the lower balancing weight 320 together allows for simple and cost-effective processing and assembly of the rotor assembly.

[0048] In the rotor assembly according to the first embodiment of the present application, the upper balancing weight 310 is stably supported by the step surface 130 of the rotor shaft 100. Even when the rotor assembly 30 rotates at high speed, the centrifugal force and bending moment generated by the eccentrically arranged upper balancing weight 310 can be transmitted to the step surface 130 of the rotor shaft 100. Since the rotor shaft 100 firmly presses the upper balancing weight 310 through the step surface, the fixed connection between the upper balancing weight 310 and the rotor 200 can be effectively maintained, preventing the connecting member 400, especially the head 410 of the connecting member, from fatigue wear and fracture. This can improve the fatigue strength of the rotor assembly and extend the service life of the rotor assembly.

[0049] Furthermore, in a compressor, the rotor assembly needs to cooperate with multiple other components, so it is very important to ensure the precise positioning of the rotor in the axial direction of the rotor shaft. In the rotor assembly according to the first embodiment of the present application, by utilizing the stepped surface 130 of the rotor shaft 100 to cooperate with the upper balancing weight 310, and the upper balancing weight 310 being fixedly connected to the rotor 200 and the lower balancing weight 320, the axial positions of the upper balancing weight 310, the rotor 200, and the lower balancing weight 310 on the rotor shaft can be precisely determined, facilitating assembly and operation of the compressor.

[0050] FIG5 shows a rotor assembly 30A according to a second embodiment of the present disclosure. The rotor assembly 30A according to the second embodiment of the present disclosure differs from the rotor assembly 30 according to the first embodiment of the present disclosure only in the structure of the rotor shaft. Specifically, in rotor assembly 30A, the rotor shaft 100A does not include any flanges. Instead, the rotor shaft 100A includes two shaft body sections having different outer diameters, wherein the first shaft body section forms a first section 110A, and the second shaft body section forms a second section 120A, thereby forming a stepped surface 130A between the first and second shaft body sections.

[0051] In the second embodiment of the present disclosure, the upper balancing weight 310 is stably supported by the stepped surface 130A of the rotor shaft 100A. Even when the rotor assembly 30 rotates at high speeds, the centrifugal force and bending moment generated by the eccentrically arranged upper balancing weight 310 are transmitted to the stepped surface 130A of the rotor shaft 100A. Because the rotor shaft 100A firmly presses the upper balancing weight 310 via the stepped surface, the fixed connection between the upper balancing weight 310 and the rotor 200 is effectively maintained. This prevents fatigue wear and fracture of the connecting member 400, particularly the head 410 of the connecting member, thereby improving the fatigue strength of the rotor assembly and extending the service life of the rotor assembly. Furthermore, compared to the rotor assembly 30, because the first shaft body section is longer in the axial direction than the flange, the first shaft body section can more stably support the upper balancing weight 310, thereby more effectively maintaining the fixed connection between the upper balancing weight 310 and the rotor 200.

[0052] Likewise, the rotor assembly 30A can also be used to accurately determine the axial positions of the upper balancing weight 310 , the rotor 200 , and the lower balancing weight 310 relative to the rotor shaft, thereby facilitating the assembly and operation of the compressor.

[0053] FIG6 shows a rotor assembly 30B according to a third embodiment of the present disclosure. The rotor assembly 30B according to the third embodiment of the present disclosure differs from the rotor assembly 30 according to the first embodiment of the present disclosure in that a retaining ring 500 is provided between the upper balancing weight 310 and the rotor 200. Specifically, the retaining ring 500 can be provided between the second annular surface 312 of the upper balancing weight 310 and the step surface 130B, and can contact the second annular surface 312 and the step surface 130B, respectively. For example, the retaining ring 500 can be manufactured separately from the rotor shaft 100B. During assembly, the retaining ring 500 is moved axially along the rotor shaft 100B until it abuts against the step surface 130B. The upper balancing weight 310, the rotor 200, and the lower balancing weight 320 are then sequentially assembled to the rotor shaft 100B. Finally, a connector 400 is used to pass through the upper balancing weight 310, the rotor 200, and the lower balancing weight 320 to secure them together.

[0054] The outer diameter of the retaining ring 500 can be greater than the first outer diameter of the flange. In other words, the retaining ring 500 can protrude outward relative to the flange, which ensures sufficient contact area between the retaining ring 500 and the upper balancing weight 310. In the rotor assembly 30 according to the first embodiment, the stepped surface 130 of the rotor shaft 100 directly contacts the upper balancing weight 310. To ensure sufficient contact area, a flange with a larger first outer diameter must be machined on the rotor shaft 100, which incurs high costs for machining the rotor shaft. In contrast, in the rotor assembly 30B according to the third embodiment, a flange with a smaller outer diameter can be combined with a retaining ring to provide sufficient support for the upper balancing weight 310 through the larger contact area between the retaining ring and the upper balancing weight. Machining a rotor shaft with such a smaller outer diameter flange can reduce production costs.

[0055] The rotor assembly 30B according to the third embodiment effectively maintains a fixed connection between the upper balancing weight 310 and the rotor 200, preventing fatigue wear and fracture of the connector 400, particularly the connector head 410, thereby improving the fatigue strength of the rotor assembly and thereby extending the service life of the rotor assembly. Furthermore, the rotor assembly 30B can also accurately determine the axial position of the upper balancing weight 310, the rotor 200, and the lower balancing weight 310 relative to the rotor shaft, facilitating assembly and operation of the compressor.

[0056] Through experimental comparison, the inventors of this application have found that, compared to existing rotor assemblies, the rotor assembly according to this application can reduce the force on the connecting parts by approximately 30% and reduce the displacement of the balancing weight relative to the rotor by approximately 10%. These experimental results demonstrate that the rotor assembly according to this application can effectively maintain a fixed connection between the balancing weight and the rotor, improve the fatigue strength of the rotor assembly, and extend the service life of the rotor assembly.

[0057] FIG7 shows a rotor assembly 30C according to a fourth embodiment of the present disclosure. The rotor assembly 30C according to the fourth embodiment of the present disclosure differs from the rotor assembly 30 according to the first embodiment of the present disclosure in that the rotor shaft 100C is formed with a stepped surface 130C that contacts the lower balancing weight 320 to stably support the lower balancing weight 320 against the rotor 200. Preferably, in the rotor assembly 30C, the area of ​​the bottom plate 322 of the lower balancing weight 320 can be larger than the area of ​​the bottom plate 312 of the upper balancing weight 310. The rotor assembly 30C according to the fourth embodiment can effectively maintain a fixed connection between the lower balancing weight 320 and the rotor 200, prevent fatigue wear and fracture of the connecting parts, improve the fatigue strength of the rotor assembly, and extend the service life of the rotor assembly. In addition, the rotor assembly 30C can also accurately determine the axial position of the upper balancing weight 310, the rotor 200, and the lower balancing weight 310 on the rotor shaft, facilitating the assembly and operation of the compressor.

[0058] This application is susceptible to various possible variations.

[0059] For example, although the rotor assembly used in a compressor (particularly a scroll compressor) is described above as an example, those skilled in the art should understand that the present disclosure is not limited thereto, and the rotor assembly according to the present disclosure can also be applied to various other rotary machines.

[0060] For another example, it is also conceivable to form a stepped surface by fixedly attaching an additional component, such as a split flange, to a rotor shaft section with a uniform outer diameter. Another example is also conceivable to provide stepped surfaces on both sides of the rotor assembly to press against both the upper and lower balancing weights. Another example is also conceivable to provide a spacer member between the bottom plates of the balancing weights rather than direct contact with the rotor end faces.

[0061] It should also be understood that the present disclosure is not limited to the specific embodiments described and illustrated herein, and that those skilled in the art may make various modifications to the exemplary embodiments without departing from the scope of the claims. It should also be understood that the features of the various embodiments may be combined or omitted without conflicting technical solutions.

Claims

1. A rotor assembly (30, 30A, 30B, 30C), comprising: A rotor shaft (100, 100A, 100B, 100C), a rotor (200), a balancing weight (300), and a connecting member (400), wherein the rotor shaft extends through the rotor and the balancing weight, and the connecting member connects the balancing weight and the rotor so that the balancing weight and the rotor are fixed relative to each other, characterized in that: The rotor shaft (100, 100A, 100B, 100C) includes a first section (110, 110A) having a first outer diameter and a second section (120, 120A) having a second outer diameter, wherein the first outer diameter is larger than the second outer diameter, thereby forming a step surface (130, 130A, 130B, 130C) between the first section and the second section, wherein the step surface is configured to be able to push the balancing weight in a direction toward the rotor.

2. The rotor assembly according to claim 1, characterized in that The rotor shaft includes a shaft body and a flange protruding from the shaft body, the flange forming the first section (110) having the first outer diameter, and the shaft body forming the second section (120) having the second outer diameter.

3. The rotor assembly according to claim 2, characterized in that: A retaining ring (500) is provided between the step surface (130B) and the balancing block so that the step surface pushes the balancing block via the retaining ring, and the outer diameter of the retaining ring is greater than the first outer diameter.

4. The rotor assembly according to claim 1, characterized in that: The rotor shaft (100A) includes a first shaft body section forming the first section (110A) having the first outer diameter and a second shaft body section forming the second section (120A) having the second outer diameter.

5. The rotor assembly according to claim 1, characterized in that: The first section and the shaft body of the rotor shaft are separate structures, and the first section is fixedly connected to the shaft body.

6. The rotor assembly according to any one of claims 1 to 5, characterized in that The step surface (130, 130A) is formed as a flat first annular surface, and the balancing weight is formed with a flat second annular surface (316) in contact with the first annular surface.

7. The rotor assembly according to any one of claims 1 to 5, characterized in that The connecting member (400) comprises a head (410) and a connecting body (420) extending from the head, the head abutting against an end surface of the balancing weight away from the rotor, and the connecting body extending through the balancing weight and the rotor.

8. The rotor assembly according to claim 7, characterized in that The connecting piece is a rivet.

9. The rotor assembly according to any one of claims 1 to 5, characterized in that The balancing weights (300) pressed by the step surface are arranged on both sides of the rotor in the axial direction.

10. The rotor assembly according to any one of claims 1 to 5, characterized in that The balancing weight (300) pushed by the step surface is arranged on a first side of the rotor in the axial direction as a first balancing weight (310), and a second balancing weight (320) configured not to be pushed is arranged on a second side of the rotor in the axial direction.

11. The rotor assembly according to claim 10, characterized in that Each of the first balancing weight and the second balancing weight has a bottom plate (312, 322) abutting against the rotor and a counterweight portion (314, 324) asymmetrically arranged on the bottom plate, and the bottom plate (312) of the first balancing weight is configured to have an inner diameter smaller than an inner diameter of the bottom plate (322) of the second balancing weight so as to be suitable for being pushed by the step surface.

12. A compressor, characterized in that: Comprising a rotor assembly according to any one of claims 1 to 11.

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