Rotor assembly and compressor

Abstract

The invention provides a rotor assembly and a compressor, the rotor assembly comprises a shaft and a radial sheath, the shaft comprises a first shaft section and a second shaft section, the outer diameter of the first shaft section is smaller than that of the second shaft section, the first shaft section and the second shaft section are connected in the axial direction of the shaft, and a step surface is formed at the joint, the radial sheath is arranged on the first shaft section in a sleeving mode, one end of the radial sheath is connected with the step face, at least part of a cooling flow channel is formed in the peripheral wall, opposite to the radial sheath, of the first shaft section, and cooling gas can be introduced into the cooling flow channel. According to the invention, the purpose of cooling the short shaft, the bearing sheath and the thrust disc at the same time can be achieved, and the problem of poor cooling effect caused by incapability of cooling the short shaft and the bearing sheath at the same time in the prior art is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and more specifically to a rotor assembly and a compressor. Background Technology

[0002] In a magnetic levitation compressor, a magnetic levitation bearing rotor is thermally fitted onto the short shaft of the rotor. The bearing rotor has laminated silicon steel sheets of a certain thickness. During operation, the magnetic circuit of the bearing passes through the bearing rotor, causing it to levitate. The long-term presence of the magnetic field within the bearing rotor generates heat due to hysteresis losses. Excessive bearing rotor temperature can affect the overall reliability of the rotor, posing a potential threat to the reliable operation of the magnetic levitation compressor.

[0003] Existing patent CN215646423U mentions a rotor cooling device, such as Figure 1 This rotor cooling device includes a cylindrical cooling body fitted onto the rotor shaft, with its outer circumferential surface adhering to the inner circumferential surface of the rotor core. Cooling channels are formed inside the cooling body, and inlets and outlets communicating with these channels are formed on its surface. The cooling channels are spirally distributed around the central axis of the rotor water jacket. This patent achieves direct cooling of the rotor. Heat generated by rotor core losses and eddy current losses in the magnets is exchanged within the cooling body, improving rotor cooling efficiency, effectively reducing rotor magnet temperature rise, lowering motor failure rates, ensuring operational safety, and contributing to increased motor power density and reduced motor production costs.

[0004] Because existing magnetic levitation bearing rotors have technical problems such as the inability to simultaneously cool the short shaft and bearing sleeve, resulting in poor cooling effect, this invention studies and designs a rotor assembly and a compressor. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the magnetic levitation bearing rotor in the prior art cannot cool the short shaft and the bearing sleeve at the same time, resulting in poor cooling effect, thereby providing a rotor assembly and a compressor.

[0006] To address the above problems, the present invention provides a rotor assembly comprising:

[0007] The shaft includes a first shaft segment and a second shaft segment. The outer diameter of the first shaft segment is smaller than that of the second shaft segment. The first shaft segment and the second shaft segment are connected along the axial direction of the shaft, and a stepped surface is formed at the connection point. The radial sleeve is sleeved on the first shaft segment, and one end of the radial sleeve is connected to the stepped surface. At least a portion of the outer peripheral wall of the first shaft segment and the shaft segment opposite to the radial sleeve is provided with a cooling channel, and cooling gas can be introduced into the cooling channel.

[0008] In some implementations...

[0009] The cooling channel includes a spiral channel formed on the outer peripheral wall of the first shaft segment. In the projection plane of the axial end face of the first shaft segment, the spiral channel runs in the opposite direction from its inlet end to its outlet end to the rotation direction of the shaft. The radial sleeve rotates integrally with the first shaft segment, and the first shaft segment rotates integrally with the second shaft segment.

[0010] In some implementations...

[0011] The axial end face of the second shaft segment that connects with the first shaft segment forms the stepped surface. One end of the cooling channel is located on the outer peripheral surface of the first shaft segment to form a cooling channel intake port. The other end of the cooling channel extends along the outer peripheral wall of the first shaft segment to the stepped surface and extends from the stepped surface toward the outer peripheral surface of the second shaft segment to form a cooling channel exhaust port.

[0012] In some implementations...

[0013] It also includes a thrust plate, which is sleeved on the first shaft segment and located away from one end of the second shaft segment. The thrust plate abuts against one end of the radial sleeve, such that the radial sleeve is located between the thrust plate and the second shaft segment. One end of the cooling channel is located on the outer circumferential surface of the first shaft segment to form a cooling channel intake port. The thrust plate is provided with an air duct, one end of which is connected to the cooling channel intake port, and the other end of which can introduce cooling gas from the outside.

[0014] In some implementations...

[0015] The air intake groove extends from one end face of the thrust disk along its axial direction to the other end face along its axial direction.

[0016] In some implementations...

[0017] There are multiple air intake slots, which are spaced apart along the circumferential direction of the thrust plate. There are also multiple cooling channels, which are spaced apart from each other. The air intake port of each cooling channel is connected to the air intake slot in a one-to-one correspondence.

[0018] In some implementations...

[0019] The thrust disk rotates integrally with the first shaft segment. In the projection plane of the axial end face of the thrust disk, the direction of the air duct from its inlet end to its outlet end is opposite to the rotation direction of the shaft.

[0020] In some implementations...

[0021] It also includes a bearing rotor core, a bearing rotor rear retaining ring, and a bearing rotor front retaining ring. The bearing rotor core is an annular structure and is fitted around the outer periphery of the radial sheath. The bearing rotor rear retaining ring is also an annular structure and is fitted around the outer periphery of the radial sheath. The bearing rotor front retaining ring is also an annular structure and is fitted around the outer periphery of the radial sheath. The bearing rotor rear retaining ring is located between the stepped surface and the bearing rotor core and abuts against both the stepped surface and the bearing rotor core. The bearing rotor front retaining ring is located on the end face of the bearing rotor core facing away from the bearing rotor rear retaining ring and abuts against the bearing rotor core.

[0022] The present invention also provides a compressor comprising the aforementioned rotor assembly.

[0023] The rotor assembly and compressor provided by the present invention have the following beneficial effects:

[0024] 1. The present invention also enables the installation of a radial sleeve at the stepped surface between the second shaft segment and the first shaft segment by setting a first shaft segment and a radial sleeve. A magnetic levitation bearing is installed outside the radial sleeve to provide support for the first and second shaft segments. Furthermore, by setting a cooling channel on the outer peripheral wall of the first shaft segment, gas can be introduced from the outside into the space between the first shaft segment and the radial sleeve to achieve a cooling effect on the first shaft segment, the radial sleeve, and the magnetic levitation bearing. This achieves the purpose of simultaneously dissipating heat and cooling the short shaft, the bearing sleeve, and the thrust plate, effectively solving the problem in the prior art that the short shaft and the bearing sleeve cannot be cooled simultaneously, resulting in poor cooling effect.

[0025] 2. The present invention also introduces cooling gas from the outside by setting a thrust plate and setting an air duct on it, which is connected to the air intake of the cooling channel of the first shaft section. While providing cooling gas to the cooling channel, it also effectively cools the thrust plate. Furthermore, the cooling channel extends to the stepped surface and flows out from the outer periphery of the stepped surface, which can further cool the second shaft section and improve the gas flow, thereby further improving the cooling effect on the short shaft, radial sleeve, and bearing core.

[0026] 3. The cooling channel of the present invention is configured as a spiral channel with its inlet end to its outlet end in the opposite direction to the rotation direction of the radial sleeve. This facilitates the intake of gas from the outside into the cooling channel of the radial sleeve, achieving automatic air intake as the shaft rotates. This enables automatic cooling of the short shaft and bearing parts without the need for auxiliary power. The higher the rotor speed, the greater the centrifugal force on the cooling medium, and the higher the flow rate of the cooling medium, the better the cooling effect. The air duct on the thrust plate of the present invention is also configured as a channel with its inlet end to its outlet end in the axial end face opposite to the rotation direction. This facilitates the intake of gas and achieves automatic air intake as the shaft rotates. The higher the rotor speed, the greater the centrifugal force on the cooling medium, and the higher the flow rate of the cooling medium, the better the cooling effect. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the longitudinal section of a rotor cooling device in the prior art;

[0028] Figure 2 This is a schematic diagram of the longitudinal section structure of the magnetic levitation rotor assembly of the present invention;

[0029] Figure 3 This is a three-dimensional structural schematic diagram of the magnetic levitation rotor assembly of the present invention;

[0030] Figure 4 This is a schematic diagram of the structure of the shaft (including the first and second shaft segments) of the present invention in the first direction;

[0031] Figure 5 This is a schematic diagram of the structure of the shaft (including the first and second shaft segments) in the second direction of the present invention;

[0032] Figure 6 This is a schematic diagram of the first embodiment of the thrust disk of the magnetic levitation rotor assembly of the present invention (the air intake groove extends in a counterclockwise direction);

[0033] Figure 7 This is a schematic diagram of the second embodiment of the thrust disk of the magnetic levitation rotor assembly of the present invention (the air intake groove extends in a clockwise direction).

[0034] Figure 1 The attached figures are labeled as follows:

[0035] 100. Cooling body; 110. Cooling water channel; 111. Water inlet opening; 112. Water outlet opening; 120. Water inlet; 130. Water outlet; 140. Rotor water jacket; 141. Boss; 150. Water inlet sealing water jacket; 151. Water inlet channel; 160. Water outlet sealing water jacket; 161. Water outlet channel; 170. Heat dissipation fins; 200. Rotary shaft; 300. Rotor core; 400. Magnet.

[0036] Figure 2-7The reference numerals in the attached figures are:

[0037] 1. Shaft; 2. Bearing rotor rear retaining ring; 3. Bearing rotor core; 4. Bearing rotor front retaining ring; 5. Radial sleeve; 6. Cooling channel; 6-1. Cooling channel exhaust port; 6-2. Cooling channel intake port; 7. Thrust plate; 8. Air duct; 9. First shaft section; 10. Second shaft section; 11. Stepped surface. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0040] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0041] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0042] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0043] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0044] like Figure 2-7 As shown, the present invention provides a rotor assembly, preferably a magnetically levitated rotor assembly, comprising:

[0045] The shaft 1 includes a first shaft segment 9 and a second shaft segment 10. The outer diameter of the first shaft segment 9 is smaller than the outer diameter of the second shaft segment 10. The first shaft segment 9 and the second shaft segment 10 are connected along the axial direction of the shaft 1, and a stepped surface 11 is formed at the connection point. The radial sleeve 5 is sleeved on the first shaft segment 9, and one end of the radial sleeve 5 is connected to the stepped surface 11. At least a portion of the outer peripheral wall of the first shaft segment 9 and the shaft segment opposite to the radial sleeve 5 is provided with a cooling channel 6, and cooling gas can be introduced into the cooling channel 6.

[0046] The present invention also enables the installation of a radial sleeve at the stepped surface between the second shaft segment and the first shaft segment by setting a first shaft segment and a radial sleeve. A magnetic levitation bearing is installed outside the radial sleeve to provide support for the first and second shaft segments. Furthermore, by setting a cooling channel on the outer peripheral wall of the first shaft segment, gas can be introduced from the outside into the space between the first shaft segment and the radial sleeve to achieve a cooling effect on the first shaft segment, the radial sleeve, and the magnetic levitation bearing. This achieves the purpose of simultaneously dissipating heat and cooling the short shaft and the bearing sleeve, effectively solving the problem in the prior art that it is impossible to cool the short shaft and the bearing sleeve at the same time, resulting in poor cooling effect.

[0047] In some implementations...

[0048] The cooling channel 6 includes a spiral channel formed on the outer peripheral wall of the first shaft segment 9. In the projection plane of the axial end face of the first shaft segment 9, the direction of the spiral channel from its inlet end to its outlet end is opposite to the rotation direction of the shaft 1. The radial sleeve 5 rotates integrally with the first shaft segment 9, and the first shaft segment 9 rotates integrally with the second shaft segment 10.

[0049] The cooling channel of the present invention is configured as a spiral channel with the direction from its inlet end to its outlet end opposite to the rotation direction of the radial sheath. This facilitates the intake of gas from the outside into the cooling channel of the radial sheath, realizing the automatic intake of gas as the shaft rotates. This achieves automatic cooling of the short shaft and bearing parts without the need for auxiliary power. The higher the rotor speed, the greater the centrifugal force on the cooling medium, and the better the cooling effect by increasing the flow rate of the cooling medium.

[0050] In some implementations...

[0051] The axial end face of the second shaft segment 10 that connects with the first shaft segment 9 forms the stepped surface 11. One end of the cooling channel 6 is located on the outer peripheral surface of the first shaft segment 9 to form a cooling channel intake port 6-2. The other end of the cooling channel 6 extends along the outer peripheral wall of the first shaft segment 9 to the stepped surface 11, and extends from the stepped surface 11 toward the outer peripheral surface of the second shaft segment 10 to form a cooling channel exhaust port 6-1.

[0052] This is a preferred structural form of the air intake and exhaust port of the cooling channel of the present invention. The cooling channel extends to the stepped surface and flows out from the outer periphery of the stepped surface, which can further cool the second shaft section and improve the gas flow, thereby further improving the cooling effect on the short shaft, radial sleeve and bearing core, etc.

[0053] The present invention preferably cools the bearing rotor from the inside, which can avoid the internal temperature rise causing the interference fit between the radial sleeve and the short shaft to decrease. When the interference fit decreases, the radial sleeve and the bearing rotor are prone to detachment, which poses a risk of failure during the operation of the magnetic levitation compressor. The cooling scheme of the present invention can ensure the interference fit requirement during the high-speed rotation of the rotor, thereby increasing the reliability of the bearing rotor in the magnetic levitation compressor.

[0054] The present invention preferably features an exhaust port groove on the end face of the cooling channel on the short shaft that is similar in shape to the impeller intake channel. The channel gradually narrows and has a specified curvature, which can reduce wind resistance and allow the cooling medium to flow faster after entering the channel, resulting in better cooling effect.

[0055] In some implementations...

[0056] It also includes a thrust disk 7, which is sleeved on the first shaft segment 9 and located away from the end of the second shaft segment 10. The thrust disk 7 abuts against one end of the radial sleeve 5, such that the radial sleeve 5 is located between the thrust disk 7 and the second shaft segment 10. One end of the cooling channel 6 is located on the outer peripheral surface of the first shaft segment 9 to form a cooling channel intake port 6-2. The thrust disk 7 is provided with an air duct 8, one end of which is connected to the cooling channel intake port 6-2, and the other end of which can introduce cooling gas from the outside.

[0057] The present invention also incorporates a thrust plate with an air vent groove, which allows cooling gas to be introduced from the outside and connected to the air intake of the cooling channel of the first shaft section. This provides cooling gas to the cooling channel while effectively cooling the thrust plate. Furthermore, the cooling channel extends to the stepped surface and flows out from the outer periphery of the stepped surface, further cooling the second shaft section and improving gas flow. This further enhances the cooling effect on the short shaft, radial sleeve, and bearing core.

[0058] In some implementations...

[0059] The air intake groove 8 extends from one end face of the thrust disk 7 along the axial direction to the other end face along the axial direction.

[0060] This is a preferred structural form of the air intake groove of the present invention, which can realize the function of supplying air to the cooling channel on the first shaft section.

[0061] In some implementations...

[0062] There are multiple air intake slots 8, which are spaced apart along the circumferential direction of the thrust disk 7. There are also multiple cooling channels 6, which are spaced apart from each other. The air intake port 6-2 of each cooling channel 6 is connected to the air intake slot 8 in a one-to-one correspondence.

[0063] The present invention, through the one-to-one correspondence of multiple air intake slots and multiple cooling channels, can increase the air supply channels to the cooling channels, increase the air supply area, increase the heat exchange area, thereby improving the cooling and heat dissipation effect on the first shaft section and bearing section.

[0064] In some implementations...

[0065] The thrust disk 7 rotates integrally with the first shaft segment 9. In the projection plane of the axial end face of the thrust disk 7, the direction of the air duct 8 from its inlet end to its outlet end is opposite to the rotation direction of the shaft 1.

[0066] The air intake groove on the thrust plate of the present invention is also configured as a channel opposite to the direction of rotation in the axial end face from its inlet end to its outlet end, which can facilitate the intake of gas and realize the function of automatic air intake as the shaft rotates. The higher the rotor speed, the greater the centrifugal force on the cooling medium, and the better the cooling effect by increasing the flow rate of the cooling medium.

[0067] This invention provides a self-cooling structure for a magnetic levitation bearing rotor. This structure allows the cooling inlet of the thrust disk to rotate with the rotor, with the inlet facing opposite to the rotor's rotation direction. During rotor rotation, the cooling medium automatically enters the internal cooling channels of the thrust disk. The internal cooling channels rotate in the opposite direction to the rotor's rotation. The cooling medium is accelerated within the channels and collects in the cooling groove on the rear end face of the thrust disk before entering the cooling channel 6 of the bearing rotor's spiral. Accelerated by the centrifugal force of the rotor's rotation, the cooling medium flows out from the exhaust port 6-1 of the cooling channel. The faster the rotor rotates, the greater the centrifugal force, and the faster the cooling medium flows in the channels, resulting in a better cooling effect on the bearing rotor.

[0068] In some implementations...

[0069] It also includes a bearing rotor core 3, a bearing rotor rear retaining ring 2, and a bearing rotor front retaining ring 4. The bearing rotor core 3 is an annular structure and is fitted around the outer periphery of the radial sleeve 5. The bearing rotor rear retaining ring 2 is also an annular structure and is fitted around the outer periphery of the radial sleeve 5. The bearing rotor front retaining ring 4 is also an annular structure and is fitted around the outer periphery of the radial sleeve 5. The bearing rotor rear retaining ring 2 is located between the stepped surface 11 and the bearing rotor core 3 and abuts against the stepped surface 11 and the bearing rotor core 3 respectively. The bearing rotor front retaining ring 4 is located on the side end face of the bearing rotor core 3 opposite to the bearing rotor rear retaining ring 2 and abuts against the bearing rotor core 3.

[0070] The bearing rotor core, bearing rotor rear retaining ring, and front retaining ring described above are part of the structure of a magnetic levitation bearing, which can provide axial and / or radial support for the first shaft section. Cooling gas can be introduced through the cooling channel on the first shaft section, thereby achieving a cooling effect on the magnetic levitation bearing section.

[0071] like Figure 2 As shown, the short shaft (including the first shaft section 9 and the second shaft section 10), the bearing rotor rear retaining ring 2, the bearing rotor core 3 (including silicon steel sheets), the bearing rotor front retaining ring 4, the radial sleeve 5, the cooling channel 6, and the thrust plate 7 are all heat-fitted onto the shaft 1, forming a rotor self-cooling channel with the spiral channel grooves on the short shaft. Figure 3 The thrust plate 7 has an air duct 8, which is connected to the cooling channel 6. When the magnetic levitation rotor rotates at high speed counterclockwise as shown in the figure, the air duct 8 will automatically enter the cooling medium. The cooling medium enters the cooling channel 6 through the thrust plate and flows out from the cooling channel exhaust port 6-1, thus completing the cooling of the thrust plate 7, the radial sleeve 5 and the silicon steel sheet.

[0072] The present invention also provides a compressor (preferably a magnetic levitation compressor) comprising the aforementioned rotor assembly.

[0073] 1. This invention provides a self-cooling structure for a magnetic levitation bearing rotor. This structure allows the cooling inlet of the thrust disc to rotate with the rotor, with the inlet position opposite to the rotor's rotation direction. During rotor rotation, the cooling medium automatically passes through the thrust disc and enters the rotor's internal spiral flow channel. At the outlet, the cooling medium flows out at an accelerated rate due to centrifugal force as the rotor rotates, achieving the cooling purpose. Furthermore, the higher the rotor speed, the greater the centrifugal force on the cooling medium, resulting in increased cooling medium flow rate and a better cooling effect.

[0074] 2. This invention provides a self-cooling structure for a magnetic levitation bearing rotor, which can achieve self-cooling of the rotor without the need for an additional cooling medium delivery device;

[0075] 3. The present invention provides a short-shaft self-cooling channel structure, wherein the shape of the exhaust port channel changes from large to small and the channel has a certain curvature, which is conducive to accelerating the flow speed of the cooling medium in the channel, reducing the wind resistance of the cooling medium in the channel, and forming a better cooling effect.

[0076] 4. This invention provides a thrust disk cooling channel structure with a self-inlet air hole, forming a simultaneous cooling system connecting the thrust disk and the bearing rotor. The thrust disk air inlet has a large cross-sectional area, allowing for a large intake of cooling medium and resulting in better cooling performance.

[0077] This invention can solve the following technical problems:

[0078] 1. Solve the problem of overheating during the high-speed rotation of the thrust disc.

[0079] 2. Solve the problem of heat generation of silicon steel sheets in magnetic levitation bearing rotors during operation.

[0080] 3. This solves the problem that current rotor cooling solutions all require opening cooling channels on the rotor shaft and separately introducing coolant for cooling, which increases the complexity of the rotor and the overall structure, and poses a risk of leakage if the coolant is not properly sealed, which can easily affect the normal operation of the compressor.

[0081] The present invention has the following beneficial effects:

[0082] 1. The implementation scheme of the present invention is simple to manufacture and highly reliable. It does not require additional cooling devices or additional sealing structures between the stator and rotor to achieve cooling of the magnetic levitation bearing rotor. Normally, the higher the rotor speed, the more severe the bearing rotor heats up. In this scheme, the bearing cooling effect will be better as the rotor speed increases and the cooling medium flow rate increases, and the temperature rise of the rotor can be well controlled.

[0083] 2. The present invention opens a spiral cooling groove on the short shaft. When the rotor rotates at high speed, the cooling medium will automatically enter the air inlet of the cooling channel and flow out through the spiral channel, forming a continuous cooling effect on the bearing rotor from the inside.

[0084] 3. By cooling the bearing rotor from the inside, this invention avoids the decrease in interference fit between the radial sleeve and the short shaft caused by the increase in internal temperature. When the interference fit decreases, the radial sleeve and the bearing rotor are more likely to fall off, reducing reliability. This invention increases the reliability of the bearing rotor in the magnetic levitation compressor.

[0085] 4. The exhaust port groove on the end face of the cooling channel on the short shaft of the present invention is similar in shape to the exhaust channel of an impeller. The channel is narrowed and has a specified curvature, which can reduce wind resistance. The cooling medium flows faster after entering the channel, resulting in better cooling effect.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A rotor assembly, characterized in that: include: The shaft (1) includes a first shaft segment (9) and a second shaft segment (10). The outer diameter of the first shaft segment (9) is smaller than the outer diameter of the second shaft segment (10). The first shaft segment (9) and the second shaft segment (10) are connected along the axial direction of the shaft (1) and a stepped surface (11) is formed at the connection point. The radial sleeve (5) is sleeved on the first shaft segment (9) and one end of the radial sleeve (5) is connected to the stepped surface (11). At least a portion of the outer peripheral wall of the first shaft segment (9) and the shaft segment opposite to the radial sleeve (5) is provided with a cooling channel (6), and cooling gas can be introduced into the cooling channel (6).

2. The rotor assembly according to claim 1, characterized in that: The cooling channel (6) includes a spiral channel formed on the outer peripheral wall of the first shaft segment (9). In the projection plane of the axial end face of the first shaft segment (9), the direction of the spiral channel from its inlet end to its outlet end is opposite to the rotation direction of the shaft (1). The radial sleeve (5) rotates integrally with the first shaft segment (9), and the first shaft segment (9) rotates integrally with the second shaft segment (10).

3. The rotor assembly according to claim 1, characterized in that: The axial end face of the second shaft segment (10) that connects with the first shaft segment (9) forms the stepped surface (11). One end of the cooling channel (6) is located on the outer peripheral surface of the first shaft segment (9) to form a cooling channel intake port (6-2). The other end of the cooling channel (6) extends along the outer peripheral wall of the first shaft segment (9) to the stepped surface (11) and extends from the stepped surface (11) toward the outer peripheral surface of the second shaft segment (10) to form a cooling channel exhaust port (6-1).

4. The rotor assembly according to claim 1, characterized in that: It also includes a thrust disk (7), which is sleeved on the first shaft segment (9) and located away from the second shaft segment (10). The thrust disk (7) abuts against one end of the radial sleeve (5), such that the radial sleeve (5) is located between the thrust disk (7) and the second shaft segment (10). One end of the cooling channel (6) is located on the outer circumferential surface of the first shaft segment (9) to form a cooling channel intake port (6-2). The thrust disk (7) is provided with an air duct (8), one end of which is connected to the cooling channel intake port (6-2), and the other end of which can introduce cooling gas from the outside.

5. The rotor assembly according to claim 4, characterized in that: The air intake groove (8) extends from one end face of the thrust disk (7) along the axial direction to the other end face along the axial direction.

6. The rotor assembly according to claim 4, characterized in that: There are multiple air intake slots (8), which are spaced apart along the circumferential direction of the thrust disk (7). There are also multiple cooling channels (6), which are spaced apart from each other. The air intake port (6-2) of each cooling channel (6) is connected to the air intake slot (8) in a one-to-one correspondence.

7. The rotor assembly according to claim 4, characterized in that: The thrust disk (7) rotates integrally with the first shaft segment (9). In the projection plane of the axial end face of the thrust disk (7), the direction of the air duct (8) from its inlet end to its outlet end is opposite to the rotation direction of the shaft (1).

8. The rotor assembly according to claim 1, characterized in that: It also includes a bearing rotor core (3), a bearing rotor rear retaining ring (2), and a bearing rotor front retaining ring (4). The bearing rotor core (3) is a ring structure and is sleeved on the outer periphery of the radial sleeve (5). The bearing rotor rear retaining ring (2) is also a ring structure and is sleeved on the outer periphery of the radial sleeve (5). The bearing rotor front retaining ring (4) is also a ring structure and is sleeved on the outer periphery of the radial sleeve (5). The bearing rotor rear retaining ring (2) is located between the stepped surface (11) and the bearing rotor core (3) and abuts against the stepped surface (11) and the bearing rotor core (3) respectively. The bearing rotor front retaining ring (4) is located on the side end face of the bearing rotor core (3) away from the bearing rotor rear retaining ring (2) and abuts against the bearing rotor core (3).

9. A compressor, characterized in that: The rotor assembly includes any one of claims 1-8.

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