Rotor structure, electric machine and compressor

Abstract

The application provides a rotor structure, a motor and a compressor, and the rotor structure comprises: a first rotor shaft, one end of the first rotor shaft being provided with a first opening; a second rotor shaft, one end of the second rotor shaft being provided with a second opening, the second opening being opposite to the first opening; a permanent magnet, which is arranged between the first rotor shaft and the second rotor shaft, the permanent magnet being a cavity structure with two open ends, and the two open ends of the permanent magnet being in abutment with the open ends of the first rotor shaft and the second rotor shaft respectively; and a sheath, which is sleeved on the first rotor shaft and the second rotor shaft and is located outside the permanent magnet, the permanent magnet being capable of driving the sheath to rotate so that the first rotor shaft and the second rotor shaft rotate synchronously with the permanent magnet. Through the technical scheme, the overall weight of the rotor structure is reduced, and the take-off rotating speed and the rotating torque of the rotor structure are reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of compressors, and particularly relates to a rotor structure, a motor and a compressor. BACKGROUND

[0002] In the prior art, the rotor structure is usually a solid shaft structure. The rotor itself is heavy, and a higher take-off rotating speed is required. On the one hand, the wear between the rotor and the bearing is intensified before the rotor is stably suspended. On the other hand, the rotor structure is a solid structure, which also increases the material cost of the rotor. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art.

[0004] To this end, the first aspect of the present application provides a rotor structure.

[0005] The second aspect of the present application provides a motor.

[0006] The third aspect of the present application provides a compressor.

[0007] The first aspect of the present application provides a rotor structure, comprising: a first rotor shaft, one end of the first rotor shaft having a first opening; a second rotor shaft, one end of the second rotor shaft having a second opening, the second opening being oppositely arranged with the first opening; a permanent magnet, arranged between the first rotor shaft and the second rotor shaft, the permanent magnet being a cavity structure with two open ends, the two open ends of the permanent magnet being in abutment with the open ends of the first rotor shaft and the second rotor shaft respectively; and a protective sleeve, sleeved on the first rotor shaft and the second rotor shaft and located outside the permanent magnet, the permanent magnet being capable of driving the protective sleeve to rotate, so that the first rotor shaft and the second rotor shaft rotate synchronously with the permanent magnet.

[0008] The present application provides a rotor structure, comprising a first rotor shaft, a second rotor shaft, a permanent magnet and a protective sleeve. One end of the first rotor shaft has a first opening, and one end of the second rotor shaft has a second opening. The first opening is oppositely arranged with the second opening.

[0009] Further, the rotor structure further comprises a permanent magnet, which is a magnetic material and is arranged between the first rotor shaft and the second rotor shaft, i.e. the permanent magnet is in abutment on one side of the first opening of the first rotor shaft and the second opening of the second rotor shaft, thereby forming a rotor structure of the first rotor shaft, the permanent magnet and the second rotor shaft.

[0010] Further, the permanent magnet is a cavity structure with two open ends, specifically, the two open ends of the permanent magnet are close to the two ends of the first rotor shaft and the second rotor shaft, the middle cavity of the permanent magnet is in communication with the openings formed by the two ends, thereby forming a hollow cylindrical structure. In this way, the weight of the permanent magnet can be further reduced, thereby reducing the weight of the rotor structure, and the take-off speed, take-off torque and the like of the rotor structure are correspondingly reduced, and the performance of the rotor structure is improved.

[0011] Further, the permanent magnet is a hollow cylindrical structure, and a cavity is formed in the permanent magnet. In this way, the shape of the permanent magnet is unchanged, and the inside is a hollow structure, so that the raw material of the permanent magnet is reduced, the weight of the permanent magnet is reduced, and the use cost is reduced.

[0012] It can be understood that, since the permanent magnet is constituted as a hollow structure, the moment of inertia of the permanent magnet is reduced. The moment of inertia depends on the mass distribution of the object, and the inside of the permanent magnet is a hollow structure, and the mass is uniformly distributed at the circumferential position of the permanent magnet. In this way, under the same torque, the starting torque of the rotor structure is reduced due to the reduction of the moment of inertia, and the speed of the rotor structure is improved, and the speed range of the rotor structure is improved.

[0013] It is worth noting that the permanent magnet abuts against the first rotor shaft and the second rotor shaft, but is not used as a connecting piece of the first rotor shaft and the second rotor shaft. It can be understood that, in order to ensure the structural strength, the first rotor shaft and the second rotor shaft are usually made of alloy steel with strong magnetic conductive material as the rotor material, and the material of the permanent magnet is usually brittle. Considering the characteristics of the permanent magnet, the permanent magnet and the first connecting shaft and the second connecting shaft are in abutting relationship in the rotor structure provided by the application, so as to prevent the permanent magnet from being directly connected with the first rotor shaft or the second rotor shaft and damaging the permanent magnet.

[0014] Further, the open end of the permanent magnet corresponds to the first opening of the first rotor shaft and the second opening of the second rotor shaft, so that the two ends of the permanent magnet can abut against the first opening of the first rotor shaft and the second opening of the second rotor shaft, thereby limiting the permanent magnet in the axial direction by the first rotor shaft and the second rotor shaft, and preventing the permanent magnet from axially moving between the first rotor shaft and the second rotor shaft.

[0015] Furthermore, the open end of the permanent magnet is clearance-fitted with the first opening of the first rotor shaft and the second opening of the second rotor shaft. Understandably, on the one hand, during assembly, the permanent magnet needs to be placed between the first and second rotor shafts. The clearance fit between the permanent magnet and the first and second rotor shafts reduces the difficulty of installation and facilitates assembly. On the other hand, when the first and second rotor shafts rotate, they generate heat through friction with the air. Based on the principle of thermal expansion and contraction, the first and second rotor shafts expand under heat and will press against the permanent magnet. The clearance fit precisely prevents the first and second rotor shafts from squeezing the permanent magnet, effectively preventing damage from compression and improving the service life of the permanent magnet.

[0016] Furthermore, the rotor structure also includes a sheath located on the outer surface of the permanent magnet and fitted onto the first and second rotor shafts, allowing the first rotor shaft, permanent magnet, and second rotor shaft to be connected via the sheath. Understandably, permanent magnets, as magnetic materials, are typically brittle and unsuitable for use as connectors. Therefore, the first and second rotor shafts are not connected via the permanent magnet itself, but rather via the sheath. In this way, by fitting the sheath onto the first and second rotor shafts and abutting against the permanent magnet, the connection between the first and second rotor shafts is achieved. Simultaneously, the sheath also protects the permanent magnet, preventing the brittle magnet from being directly exposed and damaged.

[0017] Furthermore, the axial length of the sheath is greater than the axial length of the permanent magnet. Understandably, the longer sheath increases the contact area with the first and second rotor shafts, ensuring a more effective fixation between the sheath and the first and second rotor shafts, thus improving the connection between the sheath and the first and second rotor shafts. Moreover, the greater axial length of the sheath allows it to effectively protect the permanent magnet, preventing any exposed portions of the permanent magnet from being damaged.

[0018] Furthermore, since the permanent magnet is a magnetic material, it can rotate due to changes in the magnetic field. The permanent magnet is connected to a sheath, which in turn is fitted onto the first and second rotor shafts, allowing the permanent magnet to drive the first and second rotor shafts to rotate via the sheath. It is worth noting that although the permanent magnet abuts against the first and second openings of the first and second rotor shafts, it does not directly transmit torque to the shafts. Instead, it transmits torque through the sheath, enabling the permanent magnet to drive the first and second rotor shafts to rotate synchronously.

[0019] Furthermore, the materials for the first rotor shaft and the second rotor shaft can be nickel-based alloys or high-strength stainless steel, etc.

[0020] Furthermore, the permanent magnet can be made of neodymium iron boron or samarium cobalt.

[0021] The rotor structure provided by this invention features a first rotor shaft with a first opening and a second rotor shaft with a second opening. A permanent magnet is positioned between the first and second rotor shafts, and a sheath connects them. This allows the permanent magnet to drive the first and second rotor shafts to rotate synchronously, thus achieving rotor rotation. Furthermore, by making the permanent magnet a hollow structure, the overall weight of the rotor structure is reduced. This lowers the takeoff speed and rotational torque, increasing the operating speed range. The reduced weight also lowers the rotor's moment of inertia and reduces wear between the rotor and bearings during takeoff, extending the rotor's lifespan. Finally, the hollow structure of the permanent magnet reduces material usage and lowers operating costs.

[0022] In addition, the rotor structure according to the technical solution provided by the present invention may also have the following additional technical features:

[0023] In the above technical solution, the first rotor shaft and the second rotor shaft are further hollow structures.

[0024] In this technical solution, the first and second rotor shafts are hollow structures; specifically, they are hollow cylindrical structures with cavities formed inside. Thus, the external shape of the first and second rotor shafts remains unchanged, while the internal structure is hollow, reducing the amount of raw materials used, lowering their weight, and reducing operating costs.

[0025] Furthermore, since the first and second rotor shafts are constructed as hollow structures, their moments of inertia are reduced. Understandingly, moment of inertia depends on the mass distribution of an object, and since the first and second rotor shafts have hollow interiors with mass evenly distributed around their circumferences, under the same torque, the reduced moment of inertia decreases the starting torque of the rotor structure and increases its rotational speed, thus expanding its speed range.

[0026] Furthermore, by constructing the first and second rotor shafts as hollow structures, the overall weight of the rotor structure is reduced. When the rotor structure is started, the starting torque is reduced, allowing the rotor structure to start with a smaller torque and speed, thus avoiding the need for a larger torque and speed to start the rotor structure.

[0027] It is understandable that when the first rotor shaft, the second rotor shaft, and the permanent magnet are all hollow structures, the rotor structure is the lightest, and the driving speed (takeoff speed) required to drive the rotor structure to rotate is smaller, thereby further expanding the range of rotational speeds that the rotor structure can adapt to.

[0028] In the above technical solution, the magnetic conductive element is further disposed in the cavity of the permanent magnet.

[0029] In this technical solution, the rotor structure also includes a magnetic guide component located within the cavity of the permanent magnet, allowing the magnetic lines of force of the permanent magnet to be connected. Understandably, because the permanent magnet is constructed as a cavity, the distribution of magnetic lines of force within the cavity is relatively dense, resulting in high magnetic reluctance and reduced magnetic induction, which in turn affects the rotational efficiency of the rotor structure. By incorporating a magnetic guide component within the permanent magnet, the dense magnetic lines of force within the cavity can be channeled and circulated, effectively reducing the magnetic reluctance within the permanent magnet. This improves magnetic induction and ensures the rotational efficiency of the rotor structure.

[0030] Furthermore, when the rotor structure is operating under high current, the magnetic conductor also has a strong anti-demagnetization capability, preventing the permanent magnet from demagnetizing under the action of high current and ensuring the magnetism of the permanent magnet.

[0031] Furthermore, the magnetic conductor and the permanent magnet are fitted with a small clearance. Understandably, on the one hand, during assembly, the magnetic conductor needs to be placed inside the cavity of the permanent magnet, and the clearance fit between the magnetic conductor and the permanent magnet reduces the difficulty of installing the magnetic conductor, facilitating assembly. On the other hand, the rotor structure generates heat during rotation. Based on the principle of thermal expansion and contraction, the magnetic conductor expands due to heat and will be squeezed towards the permanent magnet. The clearance fit precisely prevents the magnetic conductor from squeezing the permanent magnet, effectively preventing damage from compression and extending the service life of the permanent magnet.

[0032] In the above technical solution, the magnetic conductive element is further constructed as a cavity structure.

[0033] In this technical solution, the magnetic conductor is constructed as a hollow structure. Understandingly, designing the magnetic conductor as a hollow structure reduces the amount of raw materials used, thus lowering the overall weight. While maintaining magnetic conductivity, this reduces the weight of the rotor structure, decreasing the rotor's takeoff speed and torque, thereby reducing wear between the rotor structure and bearings and extending the rotor's service life. Furthermore, the reduced raw material cost of the magnetic conductor lowers its price, ultimately reducing the overall operating cost of the rotor structure.

[0034] Furthermore, in one possible scenario, when the first rotor shaft, the second rotor shaft, and the permanent magnet are hollow structures, high-temperature gas will be generated inside the first and second rotor shafts when the rotor structure rotates. Therefore, the magnetic conductor can be configured as a structure with a cavity extending through both ends. In this way, the high-temperature gas inside the first and second rotor shafts can enter the cavity inside the magnetic conductor, reducing the gas pressure inside the cavities of the first and second rotor shafts and preventing gas expansion inside the cavities of the first and second rotor shafts, thereby causing the first and second rotor shafts to fail.

[0035] In the above technical solution, the two ends of the magnetic conductor are respectively engaged with the first rotor shaft and the second rotor shaft.

[0036] In this technical solution, the two ends of the magnetic conductor are in contact with and engaged with the first and second rotor shafts, respectively. Understandably, since the magnetic conductor is housed within the cavity of the permanent magnet, the permanent magnet provides radial positioning for the magnetic conductor, but cannot provide axial positioning. Thus, engaging the magnetic conductor with the first and second rotor shafts ensures that both ends of the magnetic conductor tightly abut against the first opening of the first rotor shaft and the second opening of the second rotor shaft. The first and second rotor shafts fix the position of the magnetic conductor in the axial direction, thereby limiting its position in both the axial and radial directions and ensuring its proper placement within the rotor structure.

[0037] Furthermore, after the magnetic conductor is limited by the permanent magnet, the first rotor shaft, and the second rotor shaft, when the permanent magnet drives the first rotor shaft and the second rotor shaft to rotate through the sheath, the magnetic conductor can also rotate synchronously with it. Moreover, the two ends of the magnetic conductor are engaged with the first rotor shaft and the second rotor shaft, so that the magnetic conductor can still maintain its axial position when it rotates. This allows the magnetic lines of force of the permanent magnet to still be guided and circulated through the magnetic conductor, ensuring the rotation efficiency of the permanent magnet.

[0038] Furthermore, the axial length of the magnetic conductor is greater than the axial length of the permanent magnet. Understandably, this greater axial length ensures that the magnetic conductor can effectively guide the magnetic lines of force of the permanent magnet, preventing the magnetic lines of force from being completely obstructed and thus affecting the rotation of the permanent magnet, thereby guaranteeing the efficiency of the rotor structure's rotation.

[0039] In the above technical solution, the rotor structure further includes: positioning grooves, which are respectively disposed at both ends of the magnetic conductor, and the magnetic conductor is respectively engaged with the open ends of the first rotor shaft and the second rotor shaft through the positioning grooves.

[0040] In this technical solution, positioning grooves are provided at both ends of the magnetic conductor, and the positioning grooves are stepped shaft structures. The stepped shaft structure can enter the first opening of the first rotor shaft and the second opening of the second rotor shaft respectively, so that the first opening of the first rotor shaft and the second opening of the second rotor shaft can at least partially abut against the stepped shaft structure, so that the magnetic conductor can be limited by the first rotor shaft and the second rotor shaft, and the axial movement of the magnetic conductor can be avoided.

[0041] Furthermore, the positioning groove provided on the magnetic guide includes a first surface and a second surface. The first surface is capable of contacting the inner wall surfaces of the first rotor shaft and the second rotor shaft, and the second surface is capable of contacting the first opening end face of the first rotor shaft and the second opening end face of the second rotor shaft.

[0042] Understandably, the first and second surfaces together define the positioning groove. When the magnetic component engages with the first and second rotor shafts, the first surface contacts the inner wall surfaces of the first and second rotor shafts, allowing the first and second rotor shafts to radially limit the magnetic component's position, ensuring its radial orientation. Simultaneously, when the magnetic component engages with the first and second rotor shafts, the second surface also contacts them, allowing the first and second rotor shafts to axially limit the magnetic component's position, thus ensuring its axial orientation. In this way, the contact between the first and second rotor shafts via the first and second surfaces achieves the positioning of the magnetic component, preventing displacement of the magnetic component during rotor rotation.

[0043] Furthermore, the first and second rotor shafts are fitted with the magnetic conductors with an overfit or a small clearance fit.

[0044] Understandably, when the magnetic conductor has an over-fit with the first and second rotor shafts, there is no gap between the magnetic conductor and the first and second rotor shafts, resulting in a tight seal. This ensures high installation accuracy of the magnetic conductor and the first and second rotor shafts, improving the positioning accuracy of the magnetic conductor within the rotor structure. When the magnetic conductor has a small-clearance fit with the first and second rotor shafts, there is a certain gap between the magnetic conductor and the first and second rotor shafts. On one hand, this reduces installation difficulty, allowing the magnetic conductor to easily engage with the first and second rotor shafts, improving installation convenience. On the other hand, when the first and second rotor shafts rotate and generate thermal expansion and contraction, the thermal expansion of the first and second rotor shafts will squeeze the magnetic conductor. The small gap between the magnetic conductor and the first and second rotor shafts in this case prevents the first and second rotor shafts from directly squeezing the magnetic conductor, preventing damage and extending its service life.

[0045] In the above technical solution, the rotor structure further includes: a first mounting groove, disposed on the outer surface of the first rotor shaft and extending axially to the open end of the first rotor shaft; a second mounting groove, disposed on the outer surface of the second rotor shaft and extending axially to the open end of the second rotor shaft; and a sheath fixedly disposed in the first mounting groove and the second mounting groove.

[0046] In this technical solution, the rotor structure further includes a first mounting groove and a second mounting groove. The first mounting groove is located at the first rotor shaft, disposed on the outer surface of the first rotor shaft, and extends axially to the open end of the first rotor shaft to form a first mounting groove with a stepped shaft structure. The second mounting groove is located at the second rotor shaft, disposed on the outer surface of the second rotor shaft, and extends axially to the open end of the second rotor shaft to form a second mounting groove with a stepped shaft structure.

[0047] Furthermore, the first mounting groove and the second mounting groove are arranged opposite to each other, and the sheath can be disposed within the first mounting groove and the second mounting groove, so that the sheath can fit tightly against the first rotor shaft and the second rotor shaft, thereby connecting the first rotor shaft and the second rotor shaft. Moreover, since the sheath can be disposed within the first mounting groove and the second mounting groove, on the one hand, the contact area between the sheath and the first rotor shaft and the second rotor shaft can be guaranteed, improving the stability of the connection between the sheath and the first rotor shaft and the second rotor shaft. On the other hand, disposing the sheath within the first mounting groove and the second mounting groove allows for axial positioning of the sheath, ensuring accurate relative positioning of the sheath, thereby ensuring the effective fixation of the sheath to the first rotor shaft and the second rotor shaft.

[0048] Furthermore, the outer surface of the sheath is coplanar with the outer surfaces of the first and second rotor shafts. Understandably, by making the outer surface of the sheath coplanar with the outer surfaces of the first and second rotor shafts, the outer surface of the sheath does not protrude from the outer surfaces of the first and second rotor shafts. This avoids the possibility of the sheath scraping against the outside environment when the rotor structure rotates, thus improving the service life of the sheath.

[0049] Furthermore, the sheath contacts the permanent magnet and protects it. Understandably, the permanent magnet is positioned between the first rotor shaft and the second rotor shaft, while the sheath is positioned within the first and second mounting grooves, ensuring that the entire outer surface of the permanent magnet is in contact with the sheath. This prevents the permanent magnet from being directly exposed and further prevents potential damage from contact with the external environment.

[0050] Furthermore, the sheath is interference-fitted with the first mounting groove and the second mounting groove. Understandably, the interference fit between the sheath and the first mounting groove and the second mounting groove ensures a tight fit between the sheath and the second mounting groove, preventing slippage when the sheath drives the first rotor shaft and the second rotor shaft to rotate, and ensuring synchronous rotation between the sheath, the first rotor shaft and the second rotor shaft.

[0051] Furthermore, the sheath can be fixed to the first mounting groove and the second mounting groove by welding. Welding fixation can make the sheath, the first rotor shaft and the second rotor shaft into a whole, which can significantly improve the fixing effect between the sheath and the first rotor shaft and the second rotor shaft.

[0052] In the above technical solution, the sheath is further interference-fitted with the permanent magnet.

[0053] In this technical solution, the fit between the sheath and the permanent magnet is an interference fit. Understandably, the first and second rotor shafts are driven to rotate by the permanent magnet through the sheath. Setting the fit between the sheath and the permanent magnet ensures a tight fit, allowing the sheath to rotate along with the permanent magnet as it rotates. Furthermore, the interference fit allows the sheath to transmit the torque generated by the permanent magnet to the first and second rotor shafts, effectively preventing slippage between the sheath and the permanent magnet and thus avoiding reduced rotational efficiency.

[0054] Furthermore, the sheath and the permanent magnet are interference-fitted, and the sheath can always provide a certain preload to the permanent magnet, so that the permanent magnet is always under pressure when the rotor structure rotates at high speed, ensuring that the sheath and the permanent magnet will not loosen or slip, the connection is reliable, and the stability of the rotor structure at high speed is guaranteed.

[0055] Furthermore, the assembly process of the rotor structure is as follows: First, the first rotor shaft, permanent magnet, and second rotor shaft need to be placed in a normal temperature environment. The magnetic conductive component is placed in a low-temperature environment to allow it to shrink at low temperatures. The sheath is placed in a high-temperature environment to allow it to expand at high temperatures. Next, during assembly, the low-temperature shrunk magnetic conductive component is quickly installed into the first rotor shaft, followed by the permanent magnet. Then, the high-temperature sheath is installed onto the permanent magnet, and finally, the second rotor shaft is quickly installed into the sheath, completing the rotor structure assembly.

[0056] In the above technical solution, the rotor structure further includes: a first impeller; a first connecting shaft, which is disposed on the side of the first rotor shaft away from the outlet end, and the first connecting shaft is connected to the first impeller.

[0057] In this technical solution, the rotor structure also includes a first impeller and a first connecting shaft. The first connecting shaft connects the first impeller and the first rotor shaft, allowing the first impeller to be fixedly connected to the first rotor shaft, thus enabling the first impeller to rotate. Specifically, the first connecting shaft is located on the side of the first rotor shaft away from its outlet end and is connected to the first rotor shaft, allowing the first rotor shaft to transmit torque to the first connecting shaft when rotating. The first impeller is located on the side of the first connecting shaft away from the first rotor shaft and is connected to the first rotor shaft. In other words, the first impeller can be connected to the first rotor shaft via the first connecting shaft, thus allowing the first rotor shaft to transmit torque to the first impeller via the first connecting shaft, enabling the first impeller and the first connecting shaft to rotate synchronously with the first rotor shaft.

[0058] Furthermore, the first connecting shaft can be a solid shaft structure. Understandably, when the torque output by the first rotor shaft is large, the solid shaft structure of the first connecting shaft can withstand a greater torque and transmit this larger torque to the first impeller, enabling the first impeller to rotate at high speed. Thus, using a solid shaft structure for the first connecting shaft allows for the transmission of greater torque, resulting in a better connection between the first impeller and the first rotor shaft, and increasing the upper limit of the first impeller's rotational speed.

[0059] Furthermore, the first connecting shaft can be a hollow structure extending through both ends, with one end of the first connecting shaft connected to the cavity of the first rotor shaft structure. Understandably, when the first rotor shaft rotates at high speed, high-temperature, high-pressure gas is generated in its internal cavity, which can affect the reliability of the connections between components. Therefore, by setting the first connecting shaft as a hollow structure extending through both ends and connected to the cavity of the first rotor shaft, the high-temperature, high-pressure gas inside the cavity can be discharged through the first connecting shaft, preventing the high-temperature, high-pressure gas from affecting the connections between components and improving the reliability of the connections between components. Specifically, an exhaust port can be provided on the shaft of the first impeller to discharge the high-temperature, high-pressure gas.

[0060] In the above technical solution, the rotor structure further includes: a thrust plate with a through hole for the first connecting shaft to pass through and connect with the first impeller; and a sealing ring fitted around the first connecting shaft and located between the first impeller and the thrust plate.

[0061] In this technical solution, the rotor structure also includes a thrust disc and a sealing ring. The thrust disc is located on one side of the first impeller, abutting against the first rotor shaft, and provides radial support to the first rotor shaft, ensuring its radial position. Specifically, the thrust disc has a through hole through which the first connecting shaft connects the first rotor shaft to the first impeller. Since the first connecting shaft is fixedly connected to the first connecting shaft, and the thrust disc is partially fitted onto the first connecting shaft through the through hole, the thrust disc limits the first connecting shaft in the radial direction. This solid thrust disc radially limits the first rotor shaft, preventing radial runout and ensuring the stability of the first rotor shaft's rotation.

[0062] Furthermore, one end of the thrust disc abuts against the end of the first rotor shaft furthest from the open end. After the first connecting shaft is connected to the first impeller through the through hole of the thrust disc, one end of the thrust disc abuts against the end face of the first rotor shaft. When the first rotor shaft rotates, the thrust disc restricts the axial displacement of the first rotor shaft. That is, the position where the thrust disc contacts the end face of the first rotor shaft is the dead point position of the first rotor shaft, preventing the first rotor shaft from having a large range of axial displacement, thus further ensuring the stability of the rotation of the first rotor shaft.

[0063] Furthermore, a sealing ring is fitted onto the first connecting shaft, located between the first impeller and the thrust plate, to seal the first rotor shaft. Understandably, lubricating oil exists between the first rotor shaft and the bearing to reduce wear between them. When the first rotor shaft rotates, a film pressure is generated between it and the bearing, which drives the lubricating oil to flow. Fitting the sealing ring onto the first connecting shaft allows it to seal the shaft end of the first rotor shaft, preventing lubricating oil leakage, reducing the degree of leakage, and thus reducing wear between the first rotor shaft and the bearing.

[0064] Furthermore, placing the sealing ring between the first impeller and the thrust plate, and sleeved on the first connecting shaft, can also provide axial limiting for the first impeller and the thrust plate, so that there is a certain distance between the first impeller and the thrust plate, avoiding contact between the first impeller and the thrust plate, and preventing damage to the first impeller and the thrust plate.

[0065] Furthermore, the sealing ring is a floating sealing ring. Floating sealing rings have good sealing performance, high pressure bearing capacity, and low friction and wear, which can ensure the sealing effect on the first rotor shaft.

[0066] In the above technical solution, the rotor structure further includes: a second impeller; and a second connecting shaft, which is disposed on the side of the second rotor shaft away from the outlet end, and the second connecting shaft is connected to the second impeller.

[0067] In this technical solution, the rotor structure further includes a second impeller and a second connecting shaft. The second connecting shaft connects the second impeller and the second rotor shaft, allowing the second impeller to be fixedly connected to the second rotor shaft, thus enabling the second impeller to rotate. Specifically, the second connecting shaft is located on the side of the second rotor shaft away from its outlet end and is connected to the second rotor shaft, allowing the second rotor shaft to transmit torque to the second connecting shaft when rotating. The second impeller is located on the side of the second connecting shaft away from the second rotor shaft and is connected to the second rotor shaft. In other words, the second impeller can be connected to the second rotor shaft via the second connecting shaft, allowing the second rotor shaft to transmit torque to the second impeller through the second connecting shaft, enabling the second impeller and the second connecting shaft to rotate synchronously with the second rotor shaft.

[0068] Furthermore, the second connecting shaft can be a solid shaft structure. Understandably, when the torque output by the second rotor shaft is large, the solid shaft structure of the second connecting shaft can withstand a greater torque and transmit this larger torque to the second impeller, enabling high-speed rotation of the second impeller. Thus, using a solid shaft structure for the second connecting shaft allows for the transmission of greater torque, resulting in a better connection between the second impeller and the second rotor shaft, and increasing the upper speed limit of the second impeller.

[0069] Furthermore, the second connecting shaft can be a hollow structure extending through both ends, with one end of the second connecting shaft connected to the cavity of the second rotor shaft structure. Understandably, when the second rotor shaft rotates at high speed, high-temperature, high-pressure gas is generated in its internal cavity, which can affect the reliability of the connections between components. Therefore, by setting the second connecting shaft as a hollow structure extending through both ends and connected to the cavity of the second rotor shaft, the high-temperature, high-pressure gas inside the cavity can be discharged through the second connecting shaft, preventing the high-temperature, high-pressure gas from affecting the connections between components and improving the reliability of the connections between components. Specifically, an exhaust port can be provided on the shaft of the second impeller to discharge the high-temperature, high-pressure gas.

[0070] A second aspect of the present invention provides an electric motor that includes all the beneficial effects of the rotor structure described in any of the above-described technical solutions, which will not be discussed in detail hereafter.

[0071] A third aspect of the present invention provides a compressor that includes all the beneficial effects of the rotor structure in any of the above-described technical solutions, which will not be discussed in detail hereafter.

[0072] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0073] Figure 1 This is one of the schematic diagrams of the rotor structure provided in the embodiment of the present invention;

[0074] Figure 2 A radial cross-sectional view of the permanent magnet and magnetic conductor in the rotor structure provided in an embodiment of the present invention.

[0075] The correspondence between the reference numerals and the component names is as follows:

[0076] 100 First rotor shaft, 102 First opening, 104 First mounting slot, 110 Second rotor shaft, 112 Second opening, 114 Second mounting slot, 130 Permanent magnet, 140 Sheath, 150 Magnetic conductor, 152 Positioning slot, 160 First impeller, 170 First connecting shaft, 180 Thrust plate, 190 Second impeller, 200 Second connecting shaft. Detailed Implementation

[0077] To better understand the objectives, features, and advantages of this invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features of the present invention can be combined with each other.

[0078] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0079] The following reference Figure 1 , Figure 2 The present invention describes a rotor structure comprising: a first rotor shaft 100 and a second rotor shaft 110, wherein the first rotor shaft 100 and the second rotor shaft 110 are structures with an opening at one end; the openings of the first rotor shaft 100 and the second rotor shaft 110 are arranged opposite to each other; a permanent magnet 130 is provided between the first rotor shaft 100 and the second rotor shaft 110, the permanent magnet 130 being a cavity structure with openings at both ends, the two open ends of the permanent magnet 130 respectively abutting against the open ends of the first rotor shaft 100 and the second rotor shaft 110; a sheath 140 is sleeved on the first rotor shaft 100 and the second rotor shaft 110 and located outside the permanent magnet 130, the permanent magnet 130 being able to drive the first rotor shaft 100 and the second rotor shaft 110 to rotate synchronously with the permanent magnet 130 through the sheath 140.

[0080] like Figure 1 As shown, this embodiment provides a rotor structure, including a first rotor shaft 100, a second rotor shaft 110, a permanent magnet 130, and a sheath 140. The first rotor shaft 100 has a first opening 102 at one end, and the second rotor shaft 110 has a second opening 112 at one end, with the first opening 102 and the second opening 112 being arranged opposite to each other.

[0081] Furthermore, the rotor structure also includes a permanent magnet 130, which is a magnetic material and is disposed between the first rotor shaft 100 and the second rotor shaft 110. That is, the permanent magnet 130 abuts against one side of the first opening 102 of the first rotor shaft 100 and the second opening 112 of the second rotor shaft 110, thereby forming a rotor structure of the first rotor shaft 100, the permanent magnet 130 and the second rotor shaft 110.

[0082] Furthermore, the permanent magnet 130 is a hollow structure with openings at both ends. Specifically, the permanent magnet 130 is a hollow cylindrical structure with cavities formed inside. In this way, the external shape of the permanent magnet 130 remains unchanged, while the internal structure is hollow, which reduces the amount of raw materials used in the permanent magnet 130, lowers its weight, and reduces the cost of use.

[0083] Furthermore, because the permanent magnet 130 is constructed as a hollow structure, its moment of inertia is reduced. Understandably, moment of inertia depends on the mass distribution of an object, and since the permanent magnet 130 has a hollow internal structure, its mass is evenly distributed around its circumference. This reduces wear between the rotor structure and the bearings during takeoff, thus lowering the rotor structure's moment of inertia. Additionally, the reduced weight of the rotor structure itself also reduces the torque driving it. This increases the rotor structure's operating speed range, reduces wear, and extends its service life. Moreover, the hollow structure reduces the amount of raw materials used, lowering operating costs.

[0084] Furthermore, the open end of the permanent magnet 130 corresponds to the first opening 102 of the first rotor shaft 100 and the second opening 112 of the second rotor shaft 110, so that both ends of the permanent magnet 130 can abut against the first opening 102 of the first rotor shaft 100 and the second opening 112 of the second rotor shaft 110. In this way, the permanent magnet 130 is axially limited by the first rotor shaft 100 and the second rotor shaft 110 to prevent the permanent magnet 130 from axially displacing between the first rotor shaft 100 and the second rotor shaft 110.

[0085] Furthermore, the open end of the permanent magnet 130 is clearance-fitted with the first opening 102 of the first rotor shaft 100 and the second opening 112 of the second rotor shaft 110. Understandably, on the one hand, during assembly, the permanent magnet 130 needs to be placed between the first rotor shaft 100 and the second rotor shaft 110. The clearance fit between the permanent magnet 130 and the first rotor shaft 100 and the second rotor shaft 110 reduces the installation difficulty of the permanent magnet 130 and facilitates assembly. On the other hand, when the first rotor shaft 100 and the second rotor shaft 110 rotate, they generate heat through friction with the air. Based on the principle of thermal expansion and contraction, the first rotor shaft 100 and the second rotor shaft 110 expand due to heat and will squeeze towards the permanent magnet 130. The clearance fit precisely prevents the first rotor shaft 100 and the second rotor shaft 110 from squeezing the permanent magnet 130, effectively preventing damage to the permanent magnet 130 and improving its service life.

[0086] It is worth noting that the permanent magnet 130 abuts against the first rotor shaft 100 and the second rotor shaft 110, but is not used as a connecting component between the first rotor shaft 100 and the second rotor shaft 110. Understandably, the first rotor shaft 100 and the second rotor shaft 110 are typically made of alloy steel with strong magnetic conductivity to ensure structural strength. However, the material of the permanent magnet 130 is usually brittle. Considering this characteristic of the permanent magnet 130, in the rotor structure provided by this invention, the permanent magnet 130 is in an abutting relationship with the first connecting shaft 170 and the second connecting shaft 200 to prevent direct connection between the permanent magnet 130 and the first rotor shaft 100 or the second rotor shaft 110, which could damage the permanent magnet 130.

[0087] Furthermore, the rotor structure also includes a sheath 140, which is located on the outer surface of the permanent magnet 130 and sleeved on the first rotor shaft 100 and the second rotor shaft 110, allowing the first rotor shaft 100, the permanent magnet 130, and the second rotor shaft 110 to be connected through the sheath 140. Understandably, the permanent magnet 130 is a magnetic material, which is generally brittle and unsuitable for use as a connector. Therefore, the first rotor shaft 100 and the second rotor shaft 110 are not connected through the permanent magnet 130, but rather through the sheath 140. Thus, by sleeved on the first rotor shaft 100 and the second rotor shaft 110 and abutting against the permanent magnet 130, the connection between the first rotor shaft 100 and the second rotor shaft 110 is achieved. Simultaneously, the sheath 140 also protects the permanent magnet 130, preventing the brittle permanent magnet 130 from being directly exposed and damaged.

[0088] Furthermore, the axial length of the sheath 140 is greater than the axial length of the permanent magnet 130. Understandably, the longer sheath 140 increases the contact area with the first rotor shaft 100 and the second rotor shaft 110, ensuring a better fixation between the sheath 140 and the first rotor shaft 100 and the second rotor shaft 110, thus improving the connection effect. Moreover, the greater axial length of the sheath 140 allows it to effectively protect the permanent magnet 130, preventing any part of the permanent magnet 130 from being exposed and potentially damaged.

[0089] Furthermore, since the permanent magnet 130 is made of magnetic material, it can rotate due to changes in the magnetic field. The permanent magnet 130 is connected to the sheath 140, which in turn is fitted onto the first rotor shaft 100 and the second rotor shaft 110, allowing the permanent magnet 130 to drive the first rotor shaft 100 and the second rotor shaft 110 to rotate via the sheath 140. It is worth noting that although the permanent magnet 130 abuts against the first opening 102 and the second opening 112 of the first rotor shaft 100 and the second rotor shaft 110, the permanent magnet 130 does not directly transmit torque to the first rotor shaft 100 and the second rotor shaft 110. Instead, it transmits torque through the sheath 140, enabling the permanent magnet 130 to drive the first rotor shaft 100 and the second rotor shaft 110 to rotate synchronously via the sheath 140.

[0090] Furthermore, the materials of the first rotor shaft 100 and the second rotor shaft 110 can be nickel-based alloys or high-strength stainless steel, etc.

[0091] Furthermore, the permanent magnet 130 can be made of neodymium iron boron or samarium cobalt.

[0092] The rotor structure provided by this invention, by setting a first opening 102 in the first rotor shaft 100 and a second opening 112 in the second rotor shaft 110, and placing a permanent magnet 130 between the first rotor shaft 100 and the second rotor shaft 110, connects the first rotor shaft 100 and the second rotor shaft 110 through a sheath 140, so that the permanent magnet 130 can drive the first rotor shaft 100 and the second rotor shaft 110 to rotate synchronously through the sheath 140, thus realizing the rotation of the rotor structure. Simultaneously, by making the permanent magnet 130 a hollow structure, the overall weight of the rotor structure is reduced. On the one hand, this lowers the takeoff speed and rotational torque of the rotor structure, increasing the operating speed range of the rotor structure. On the other hand, the reduced weight of the rotor structure lowers the rotational inertia of the rotor structure, and simultaneously reduces wear between the rotor structure and bearings during takeoff, improving the service life of the rotor structure. Furthermore, since the permanent magnet 130 has a hollow structure, the use of materials is reduced, lowering the operating cost.

[0093] This embodiment provides a rotor structure, which, in addition to the technical features of the above embodiments, further includes the following technical features.

[0094] like Figure 1 and Figure 2 As shown, the first rotor shaft 100 and the second rotor shaft 110 are hollow structures.

[0095] In this embodiment, the first rotor shaft 100 and the second rotor shaft 110 are hollow structures. Specifically, the first rotor shaft 100 and the second rotor shaft 110 are hollow cylindrical structures, with cavities formed inside them. Thus, the external shape of the first rotor shaft 100 and the second rotor shaft 110 remains unchanged, while the internal structure is hollow, reducing the amount of raw materials used in the first rotor shaft 100 and the second rotor shaft 110, lowering their weight, and reducing usage costs.

[0096] Furthermore, since the first rotor shaft 100 and the second rotor shaft 110 are configured as hollow structures, their moments of inertia are reduced. Understandably, moment of inertia depends on the mass distribution of an object, and since the interiors of the first rotor shaft 100 and the second rotor shaft 110 are hollow, the mass is evenly distributed around their circumferences. Thus, under the same torque, the reduced moment of inertia decreases the starting torque of the rotor structure and increases its rotational speed, thereby expanding its speed range.

[0097] Furthermore, the first rotor shaft 100 and the second rotor shaft 110 are constructed as hollow structures, which reduces the overall weight of the rotor structure. When the rotor structure is started, the starting torque can be reduced, allowing the rotor structure to start with a smaller torque and speed, avoiding the need for a larger torque and speed to start the rotor structure.

[0098] It is understandable that when the first rotor shaft 100, the second rotor shaft 110 and the permanent magnet 130 are all hollow structures, the rotor structure is the lightest and the driving speed (take-off speed) required to drive the rotor structure to rotate is smaller, thereby further expanding the range of rotational speeds that the rotor structure can adapt to.

[0099] This embodiment provides a rotor structure, which, in addition to the technical features of the above embodiments, further includes the following technical features.

[0100] like Figure 1 and Figure 2 As shown, the magnetic conductor 150 is disposed in the cavity of the permanent magnet 130.

[0101] In this embodiment, the rotor structure also includes a magnetic conductor 150, which is located within the cavity of the permanent magnet 130. The magnetic lines of force of the permanent magnet 130 can be connected through the magnetic conductor 150. Understandably, because the permanent magnet 130 is constructed as a cavity, the distribution of magnetic lines of force within the cavity is relatively dense, resulting in high magnetic reluctance and reduced magnetic induction, which in turn affects the rotational efficiency of the rotor structure. By providing the magnetic conductor 150 within the permanent magnet 130, the dense magnetic lines of force within the cavity can be guided and circulated through the magnetic conductor 150, effectively reducing the magnetic reluctance within the permanent magnet 130. This improves magnetic induction and ensures the rotational efficiency of the rotor structure.

[0102] Furthermore, when the rotor structure is operating under high current, the magnetic conductor 150 also has a strong anti-demagnetization capability, preventing the permanent magnet 130 from demagnetizing under the action of high current and ensuring the magnetism of the permanent magnet 130.

[0103] Furthermore, the magnetic conductor 150 and the permanent magnet 130 are fitted with a small clearance. Understandably, on the one hand, during assembly, the magnetic conductor 150 needs to be placed inside the cavity of the permanent magnet 130. The clearance fit between the magnetic conductor 150 and the permanent magnet 130 reduces the installation difficulty of the magnetic conductor 150, facilitating assembly. On the other hand, the rotor structure generates heat during rotation. Based on the principle of thermal expansion and contraction, the magnetic conductor 150 expands due to heat and will be squeezed towards the permanent magnet 130. The clearance fit precisely prevents the magnetic conductor 150 from squeezing the permanent magnet 130, effectively preventing damage to the permanent magnet 130 and extending its service life.

[0104] This embodiment provides a rotor structure, which, in addition to the technical features of the above embodiments, further includes the following technical features.

[0105] like Figure 1 and Figure 2 As shown, the magnetic conductor 150 is constructed as a cavity structure.

[0106] In this embodiment, the magnetic conductor 150 is constructed as a hollow structure. Understandably, by making the magnetic conductor 150 a hollow structure, the amount of raw materials used in the magnetic conductor 150 can be reduced. On the one hand, this reduces the overall weight, thereby reducing the weight of the rotor structure while maintaining magnetic conductivity, decreasing the rotor's takeoff speed and takeoff torque, and consequently reducing wear between the rotor structure and the bearings, thus increasing the rotor structure's service life. On the other hand, the reduction in raw materials for the magnetic conductor 150 lowers its cost, thereby reducing the overall operating cost of the rotor structure.

[0107] Furthermore, in one possible scenario, when the first rotor shaft 100, the second rotor shaft 110, and the permanent magnet 130 are hollow structures, high-temperature gas will be generated inside the first rotor shaft 100 and the second rotor shaft 110 when the rotor structure rotates. Therefore, the magnetic conductor 150 can be configured as a structure with a cavity extending through the openings at both ends. In this way, the high-temperature gas inside the first rotor shaft 100 and the second rotor shaft 110 can enter the cavity inside the magnetic conductor 150, reducing the gas pressure inside the cavity of the first rotor shaft 100 and the second rotor shaft 110, and preventing gas from expanding inside the cavity of the first rotor shaft 100 and the second rotor shaft 110, thereby causing the failure of the first rotor shaft 100 and the second rotor shaft 110.

[0108] This embodiment provides a rotor structure, which, in addition to the technical features of the above embodiments, further includes the following technical features.

[0109] like Figure 1 As shown, the two ends of the magnetic conductor 150 are respectively engaged with the first rotor shaft 100 and the second rotor shaft 110.

[0110] In this embodiment, the two ends of the magnetic conductor 150 contact and are engaged with the first rotor shaft 100 and the second rotor shaft 110, respectively. Understandably, since the magnetic conductor 150 is disposed within the cavity of the permanent magnet 130, the permanent magnet 130 can provide radial positioning for the magnetic conductor, but cannot provide axial positioning for the magnetic conductor 150. Thus, engaging the magnetic conductor 150 with the first rotor shaft 100 and the second rotor shaft 110 tightly abuts against the first opening 102 of the first rotor shaft 100 and the second opening 112 of the second rotor shaft 110. The first rotor shaft 100 and the second rotor shaft 110 fix the position of the magnetic conductor 150 in the axial direction, thereby limiting the magnetic conductor 150 in both the axial and radial directions, ensuring its position within the rotor structure.

[0111] Furthermore, after the magnetic conductor 150 is limited by the permanent magnet 130, the first rotor shaft 100, and the second rotor shaft 110, when the permanent magnet 130 drives the first rotor shaft 100 and the second rotor shaft 110 to rotate through the sheath 140, the magnetic conductor 150 can also rotate synchronously with it. Moreover, the two ends of the magnetic conductor 150 are engaged with the first rotor shaft 100 and the second rotor shaft 110, so that the magnetic conductor 150 can still maintain its axial position when it rotates. In this way, the magnetic lines of force of the permanent magnet 130 can still be guided and circulated through the magnetic conductor 150, so that the permanent magnet 130 can maintain its rotation efficiency.

[0112] Furthermore, the axial length of the magnetic conductor 150 is greater than the axial length of the permanent magnet 130. Understandably, the greater axial length of the magnetic conductor 150 ensures that the magnetic conductor 150 can effectively guide the magnetic lines of force of the permanent magnet 130, preventing the magnetic lines of force from being completely obstructed by the magnetic conductor 150, which would affect the rotation of the permanent magnet 130 and thus guarantee the efficiency of the rotor structure's rotation.

[0113] This embodiment provides a rotor structure, which, in addition to the technical features of the above embodiments, further includes the following technical features.

[0114] like Figure 1 As shown, the rotor structure also includes positioning grooves 152, which are located at both ends of the magnetic conductor 150. The magnetic conductor 150 is engaged with the open ends of the first rotor shaft 100 and the second rotor shaft 110 through the positioning grooves 152.

[0115] In this embodiment, positioning grooves 152 are provided at both ends of the magnetic conductor 150. The positioning grooves 152 are stepped shaft structures. The stepped shaft structure can enter the first opening 102 of the first rotor shaft 100 and the second opening 112 of the second rotor shaft 110, respectively, so that the first opening 102 of the first rotor shaft 100 and the second opening 112 of the second rotor shaft 110 can at least partially abut against the stepped shaft structure, so that the magnetic conductor 150 can be limited by the first rotor shaft 100 and the second rotor shaft 110, and the axial movement of the magnetic conductor 150 is prevented.

[0116] Furthermore, the positioning groove 152 provided on the magnetic guide 150 includes a first surface and a second surface. The first surface can contact the inner wall surface of the first rotor shaft 100 and the second rotor shaft 110, and the second surface can contact the end face of the first opening 102 of the first rotor shaft 100 and the second opening 112 of the second rotor shaft 110.

[0117] Understandably, the first and second surfaces together define the positioning groove 152. When the magnetic conductor 150 engages with the first rotor shaft 100 and the second rotor shaft 110, the first surface contacts the inner wall surfaces of the first rotor shaft 100 and the second rotor shaft 110, allowing the first rotor shaft 100 and the second rotor shaft 110 to radially limit the magnetic conductor 150 through the first surface, ensuring the radial position of the magnetic conductor 150. Simultaneously, when the magnetic conductor 150 engages with the first rotor shaft 100 and the second rotor shaft 110, the second surface also contacts the first rotor shaft 100 and the second rotor shaft 110, allowing the first rotor shaft 100 and the second rotor shaft 110 to axially limit the magnetic conductor 150 through the second surface, thereby ensuring the axial position of the magnetic conductor 150. Thus, the first rotor shaft 100 and the second rotor shaft 110, through the contact of the first and second surfaces, achieve positioning of the magnetic conductor 150, preventing displacement of the magnetic conductor 150 during rotor structure rotation.

[0118] Furthermore, the first rotor shaft 100 and the second rotor shaft 110 are fitted with the magnetic conductor 150 with an overfit or a small clearance fit.

[0119] Understandably, when the magnetic conductor 150 has an over-fit with the first rotor shaft 100 and the second rotor shaft 110, there is no gap and they fit together perfectly. This results in high installation accuracy for the magnetic conductor 150 and the first rotor shaft 100 and the second rotor shaft 110, improving the positioning accuracy of the magnetic conductor 150 in the rotor structure. When the magnetic conductor 150 has a small clearance fit with the first rotor shaft 100 and the second rotor shaft 110, there is a certain gap between the magnetic conductor 150 and the first rotor shaft 100 and the second rotor shaft 110. On the one hand, this reduces the installation difficulty when installing the magnetic conductor 150 and the first rotor shaft 100 and the second rotor shaft 110, allowing the magnetic conductor 150 to easily engage with the first rotor shaft 100 and the second rotor shaft 110, thus improving installation convenience. On the other hand, when the first rotor shaft 100 and the second rotor shaft 110 rotate and generate a thermal expansion and contraction effect, the first rotor shaft 100 and the second rotor shaft 110 will squeeze the magnetic conductor 150 after being heated and expanded. At this time, the small gap between the magnetic conductor 150 and the first rotor shaft 100 and the second rotor shaft 110 can prevent the first rotor shaft 100 and the second rotor shaft 110 from directly squeezing the magnetic conductor 150, preventing the magnetic conductor 150 from being squeezed and damaged, and improving the service life of the magnetic conductor 150.

[0120] This embodiment provides a rotor structure, which, in addition to the technical features of the above embodiments, further includes the following technical features.

[0121] like Figure 1 As shown, the rotor structure also includes a first mounting groove 104 and a second mounting groove 114. The first mounting groove 104 is disposed on the outer surface of the first rotor shaft 100 and extends axially to the open end of the first rotor shaft 100. The second mounting groove 114 is disposed on the outer surface of the second rotor shaft 110 and extends axially to the open end of the second rotor shaft 110. The sheath 140 is fixedly disposed in the first mounting groove 104 and the second mounting groove 114.

[0122] In this embodiment, the rotor structure further includes a first mounting groove 104 and a second mounting groove 114. The first mounting groove 104 is located at the first rotor shaft 100, disposed on the outer surface of the first rotor shaft 100, and extends axially to the open end of the first rotor shaft 100 to form a stepped shaft structure. The second mounting groove 114 is located at the second rotor shaft 110, disposed on the outer surface of the second rotor shaft 110, and extends axially to the open end of the second rotor shaft 110 to form a stepped shaft structure.

[0123] Furthermore, the first mounting groove 104 and the second mounting groove 114 are arranged opposite to each other, and the sheath 140 can be disposed within the first mounting groove 104 and the second mounting groove 114, so that the sheath 140 can fit tightly against the first rotor shaft 100 and the second rotor shaft 110, thereby connecting the first rotor shaft 100 and the second rotor shaft 110. Moreover, since the sheath 140 can be disposed within the first mounting groove 104 and the second mounting groove 114, on the one hand, the contact area between the sheath 140 and the first rotor shaft 100 and the second rotor shaft 110 can be guaranteed, improving the connection stability between the sheath 140 and the first rotor shaft 100 and the second rotor shaft 110. On the other hand, disposing the sheath 140 within the first mounting groove 104 and the second mounting groove 114 allows for axial positioning of the sheath 140, ensuring accurate relative positioning of the sheath 140, thereby ensuring the fixing effect between the sheath 140 and the first rotor shaft 100 and the second rotor shaft 110.

[0124] Furthermore, the outer surface of the sheath 140 is coplanar with the outer surfaces of the first rotor shaft 100 and the second rotor shaft 110. Understandably, by making the outer surface of the sheath 140 coplanar with the outer surfaces of the first rotor shaft 100 and the second rotor shaft 110, the outer surface of the sheath 140 does not protrude from the outer surfaces of the first rotor shaft 100 and the second rotor shaft 110. This avoids the possibility of the sheath 140 scraping against the outside environment when the rotor structure rotates, thus improving the service life of the sheath 140.

[0125] Furthermore, the sheath 140 contacts the permanent magnet 130 and protects the permanent magnet 130. Understandably, the permanent magnet 130 is disposed between the first rotor shaft 100 and the second rotor shaft 110, while the sheath 140 is disposed within the first mounting groove 104 and the second mounting groove 114, allowing the entire outer surface of the permanent magnet 130 to contact the sheath 140, preventing the permanent magnet 130 from being directly exposed and further preventing the possibility of damage from contact with the external environment.

[0126] Furthermore, the sheath 140 is interference-fitted with the first mounting groove 104 and the second mounting groove 114. Understandably, this interference fit ensures a tight fit between the sheath 140 and the first mounting groove 104 and the second mounting groove 114, preventing slippage when the sheath 140 drives the first rotor shaft 100 and the second rotor shaft 110 to rotate, thus ensuring synchronous rotation between the sheath 140, the first rotor shaft 100, and the second rotor shaft 110.

[0127] Furthermore, the sheath 140 can be fixed to the first mounting groove 104 and the second mounting groove 114 by welding. Welding fixation can make the sheath 140, the first rotor shaft 100 and the second rotor shaft 110 form a whole, which can significantly improve the fixing effect between the sheath 140 and the first rotor shaft 100 and the second rotor shaft 110.

[0128] This embodiment provides a rotor structure. In addition to the technical features of the above embodiments, this embodiment further includes the following technical features: the sheath 140 and the permanent magnet 130 are interference-fitted.

[0129] In this embodiment, the fit between the sheath 140 and the permanent magnet 130 is an interference fit. Understandably, the first rotor shaft 100 and the second rotor shaft 110 are rotated by the permanent magnet 130 via the sheath 140. Setting the sheath 140 and the permanent magnet 130 as an interference fit allows for a tight fit between them. Thus, when the permanent magnet 130 rotates, the sheath 140 can rotate with it. Furthermore, because of the interference fit, the sheath 140 can transmit the torque generated by the permanent magnet 130 to the first rotor shaft 100 and the second rotor shaft 110, effectively preventing slippage between the sheath 140 and the permanent magnet 130 and thus avoiding reduced rotation efficiency.

[0130] Furthermore, the sheath 140 and the permanent magnet 130 are interference fit, and the sheath 140 can always provide a certain preload to the permanent magnet 130, so that the permanent magnet 130 is always under pressure when the rotor structure rotates at high speed, ensuring that the sheath 140 and the permanent magnet 130 will not loosen or slip, the connection is reliable, and the stability of the rotor structure at high speed is guaranteed.

[0131] Furthermore, the assembly process of the rotor structure is as follows: First, the first rotor shaft 100, permanent magnet 130, and second rotor shaft 110 need to be placed in a normal temperature environment. The magnetic conductor 150 is placed in a low temperature environment to allow it to shrink at low temperatures. The sheath 140 is placed in a high temperature environment to allow it to expand at high temperatures. Next, during assembly, the low-temperature shrunk magnetic conductor 150 is quickly inserted into the first rotor shaft 100, then the permanent magnet 130 is quickly fitted onto it. Next, the high-temperature sheath 140 is fitted onto the permanent magnet 130. Finally, the second rotor shaft 110 is quickly inserted into the sheath 140, completing the rotor structure assembly.

[0132] This embodiment provides a rotor structure, which, in addition to the technical features of the above embodiments, further includes the following technical features.

[0133] like Figure 1As shown, the rotor structure also includes: a first impeller 160; and a first connecting shaft 170, which is disposed on the side of the first rotor shaft 100 away from the outlet end, and the first connecting shaft 170 is connected to the first impeller 160.

[0134] In this embodiment, the rotor structure further includes a first impeller 160 and a first connecting shaft 170. The first connecting shaft 170 connects the first impeller 160 and the first rotor shaft 100, allowing the first impeller 160 to be fixedly connected to the first rotor shaft 100, thereby enabling the first impeller 160 to rotate. Specifically, the first connecting shaft 170 is located on the side of the first rotor shaft 100 away from its outlet end and is connected to the first rotor shaft 100, allowing the first rotor shaft 100 to transmit torque to the first connecting shaft 170 during rotation. The first impeller 160 is located on the side of the first connecting shaft 170 away from the first rotor shaft 100 and is connected to the first rotor shaft 100. In other words, the first impeller 160 can be connected to the first rotor shaft 100 via the first connecting shaft 170, thus enabling the first rotor shaft 100 to transmit torque to the first impeller 160 via the first connecting shaft 170, allowing the first impeller 160 and the first connecting shaft 170 to rotate synchronously with the first rotor shaft 100.

[0135] Furthermore, the first connecting shaft 170 can be a solid shaft structure. Understandably, when the torque output by the first rotor shaft 100 is large, the solid shaft structure of the first connecting shaft 170 can withstand a greater torque and transmit this larger torque to the first impeller 160, enabling the first impeller 160 to rotate at high speed. Thus, using a solid shaft structure for the first connecting shaft allows for the transmission of greater torque, resulting in a better connection between the first impeller 160 and the first rotor shaft 100, and increasing the upper speed limit of the first impeller 160.

[0136] Furthermore, the first connecting shaft 170 can be a hollow structure extending through both ends, with one end of the first connecting shaft 170 connected to the cavity of the first rotor shaft 100 structure. Understandably, when the first rotor shaft 100 rotates at high speed, high-temperature and high-pressure gas is generated in its internal cavity, which can affect the reliability of the connections between components. Therefore, by configuring the first connecting shaft 170 as a hollow structure extending through both ends and connected to the cavity of the first rotor shaft 100, the high-temperature and high-pressure gas in the cavity can be discharged through the first connecting shaft 170, preventing the high-temperature and high-pressure gas from affecting the connections between components and improving the reliability of the connections between components. Specifically, an exhaust port can be provided on the shaft of the first impeller 160 to discharge the high-temperature and high-pressure gas.

[0137] This embodiment provides a rotor structure, which, in addition to the technical features of the above embodiments, further includes the following technical features.

[0138] likeFigure 1 As shown, the rotor structure also includes: a thrust plate 180, which has a through hole through which the first connecting shaft 170 passes to connect with the first impeller 160; and a sealing ring, which is sleeved on the outside of the first connecting shaft 170 and located between the first impeller 160 and the thrust plate 180.

[0139] In this embodiment, the rotor structure further includes a thrust plate 180 and a sealing ring. The thrust plate 180 is located on one side of the first impeller 160, abutting against the first rotor shaft 100, and provides radial support to the first rotor shaft 100, ensuring its radial position. Specifically, the thrust plate 180 has a through hole through which the first connecting shaft 170 connects the first rotor shaft 100 to the first impeller 160. Since the first connecting shaft 170 is fixedly connected to the first connecting shaft 170, and the thrust plate 180 is partially sleeved on the first connecting shaft 170 through the through hole, the first connecting shaft 170 is radially limited by the thrust plate 180. This solid thrust plate 180 radially limits the first rotor shaft 100, preventing radial runout and ensuring the stability of the first rotor shaft 100's rotation.

[0140] Furthermore, one end of the thrust plate 180 abuts against the end of the first rotor shaft 100 furthest from the open end. After the first connecting shaft 170 is connected to the first impeller 160 through the through hole of the thrust plate 180, one end of the thrust plate 180 abuts against the end face of the first rotor shaft 100. When the first rotor shaft 100 rotates, the thrust plate 180 restricts the displacement of the first rotor shaft 100 in the axial direction. That is, the position where the thrust plate 180 contacts the end face of the first rotor shaft 100 is the dead point position of the first rotor shaft 100, which prevents the first rotor shaft 100 from having a large range of displacement in the axial direction, further ensuring the stability of the rotation of the first rotor shaft 100.

[0141] Furthermore, a sealing ring is fitted onto the first connecting shaft 170, located between the first impeller 160 and the thrust plate 180, to seal the first rotor shaft 100. Understandably, lubricating oil exists between the first rotor shaft 100 and the bearing to reduce wear between them. When the first rotor shaft 100 rotates, a film pressure is generated between it and the bearing, which drives the lubricating oil to flow. Fitting the sealing ring onto the first connecting shaft 170 allows the sealing ring to seal the shaft end of the first rotor shaft 100, preventing lubricating oil leakage, reducing the degree of lubricating oil leakage, and thus reducing wear between the first rotor shaft 100 and the bearing.

[0142] Furthermore, by placing the sealing ring between the first impeller 160 and the thrust plate 180 and sleeved on the first connecting shaft 170, the first impeller 160 and the thrust plate 180 can be axially limited, so that there is a certain distance between the first impeller 160 and the thrust plate 180, avoiding contact between the first impeller 160 and the thrust plate 180, and preventing damage to the first impeller 160 and the thrust plate 180.

[0143] Furthermore, the sealing ring is a floating sealing ring. The floating sealing ring has good sealing performance, high pressure bearing capacity, and low friction and wear, which can ensure the sealing effect on the first rotor shaft 100.

[0144] This embodiment provides a rotor structure, which, in addition to the technical features of the above embodiments, further includes the following technical features.

[0145] like Figure 1 As shown, the rotor structure also includes: a second impeller 190; and a second connecting shaft 200, which is disposed on the side of the second rotor shaft 110 away from the outlet end, and the second connecting shaft 200 is connected to the second impeller 190.

[0146] In this embodiment, the rotor structure further includes a second impeller 190 and a second connecting shaft 200. In this technical solution, the rotor structure also includes a second impeller 190 and a second connecting shaft 200. The second connecting shaft 200 is used to connect the second impeller 190 and the second rotor shaft 110, enabling the second impeller 190 to be fixedly connected to the second rotor shaft 110, thereby allowing the second impeller 190 to rotate. Specifically, the second connecting shaft 200 is located on the side of the second rotor shaft 110 away from its outlet end and is connected to the second rotor shaft 110, so that the second rotor shaft 110 can transmit torque to the second connecting shaft 200 when rotating. The second impeller 190 is located on the side of the second connecting shaft 200 away from the second rotor shaft 110 and is connected to the second rotor shaft 110. In other words, the second impeller 190 can be connected to the second rotor shaft 110 through the second connecting shaft 200. Thus, the second rotor shaft 110 can transmit torque to the second impeller 190 through the second connecting shaft 200, so that the second impeller 190 and the second connecting shaft 200 can rotate synchronously with the second rotor shaft 110.

[0147] Furthermore, the second connecting shaft 200 can be a solid shaft structure. Understandably, when the torque output by the second rotor shaft 110 is large, the solid shaft structure of the second connecting shaft 200 can withstand a greater torque and transmit this larger torque to the second impeller 190, enabling the second impeller 190 to rotate at high speed. Thus, using a solid shaft structure for the second connecting shaft allows for the transmission of greater torque, resulting in a better connection between the second impeller 190 and the second rotor shaft 110, and increasing the upper speed limit of the second impeller 190.

[0148] Furthermore, the second connecting shaft 200 can be a hollow structure extending through both ends, with one end of the second connecting shaft 200 connected to the cavity of the second rotor shaft 110 structure. Understandably, when the second rotor shaft 110 rotates at high speed, high-temperature and high-pressure gas is generated in its internal cavity, which can affect the reliability of the connections between components. Therefore, by configuring the second connecting shaft 200 as a hollow structure extending through both ends and connected to the cavity of the second rotor shaft 110, the high-temperature and high-pressure gas in the cavity can be discharged through the second connecting shaft 200, preventing the high-temperature and high-pressure gas from affecting the connections between components and improving the reliability of the connections between components. Specifically, an exhaust port can be provided on the shaft of the second impeller 190 to discharge the high-temperature and high-pressure gas.

[0149] The second aspect of this embodiment provides an electric motor that includes all the beneficial effects of the rotor structure as described in any of the above embodiments, which will not be discussed in detail hereafter.

[0150] The third aspect of this embodiment provides a compressor that includes all the beneficial effects of the rotor structure as described in any of the above embodiments, which will not be discussed in detail hereafter. Specific implementation examples:

[0152] my country is the world's largest producer, consumer, and exporter of refrigeration products, with refrigeration energy consumption accounting for 15% of total social energy consumption. During peak summer seasons, the increased load on air conditioning and other cooling loads not only places a heavy burden on the power grid but also generates significant greenhouse gas emissions. Therefore, promoting green and efficient refrigeration has become an important and urgent need for countries to promote energy conservation and emission reduction and address climate change.

[0153] In the current context of "carbon neutrality and carbon peaking," the development of low-carbon refrigeration equipment is imperative. The core component of a refrigeration system is the refrigeration compressor. In traditional refrigeration compressors, the lubricating medium for sliding bearings is lubricating oil. However, its high viscosity leads to significant frictional power loss at high speeds. Furthermore, the presence of lubricating oil over time can negatively impact the heat exchanger's efficiency, resulting in a decline in refrigeration system performance. Magnetic levitation bearings offer advantages such as low frictional loss and good stability, but their higher cost limits their advantages in small and medium-sized compressor applications.

[0154] Hydrodynamic gas bearings offer advantages such as high speed, high efficiency, and low friction loss, making them ideal for small and medium-sized compressors. Foil gas hydrodynamic bearings utilize the high-speed rotation of the rotor to drive the gas on its surface to rotate at high speed. Through the wedge effect between the rotor and the gas hydrodynamic bearing, high-pressure gas is formed at the bottom of the rotor, generating an upward supporting force to overcome the rotor's gravity and achieve stable rotor levitation. The higher the rotor speed, the greater the supporting force generated. During the process of levitation from zero speed to stable levitation, dry friction exists between the gas hydrodynamic bearing and the rotor, causing frictional wear on the hydrodynamic gas bearing.

[0155] Traditional rotor structures include impellers, sealing adjustment rings, thrust plates, front radial bearing rotors, sheaths, magnets, rear radial bearing rotors, impellers, and other components. The rotor structure has a large rotor weight and a large moment of inertia, which leads to increased friction and wear as the takeoff speed and takeoff time increase.

[0156] The purpose of this invention is to provide a rotor structure that reduces the rotor's mass, lowers its takeoff speed, and increases the operating speed range. It also reduces wear between the rotor and bearings, thus lowering the takeoff torque. Furthermore, it saves on raw materials and reduces costs.

[0157] This invention proposes a rotor structure with low takeoff speed and low moment of inertia, the structure of which is as follows: Figure 1 As shown, a permanent magnet 130 is used, and a magnetic conductor 150 is placed inside the permanent magnet 130. The magnetic conductor 150 and the permanent magnet 130 are fitted with a small clearance. Its cross-sectional view is shown in Figure 2. The magnetic conductor 150 reduces the magnetic resistance between the N and S poles of the permanent magnet 130. While reducing the amount of permanent magnet 130 used, it ensures that the motor has a high power factor. At the same time, the toroidal nature of the magnetic conductor 150 can reduce the rotor weight and moment of inertia. The amount of permanent magnet 130 material used is reduced by more than 50%, and the weight of the motor rotor is reduced by more than 30%.

[0158] In the rotor structure provided by this invention, the first rotor shaft 100 and the second rotor shaft 110 are both hollow thin-walled structures and are made of high-strength non-magnetic material. Their inner walls are fitted with a small gap or transition fit with the outer circle of the magnetic component 150, which reduces the weight and moment of inertia of the rotor while ensuring the overall rigidity of the rotor.

[0159] Furthermore, such as ​ As shown, a magnetic conductor 150 is located inside the permanent magnet 130. The material of the magnetic conductor 150 can be 45 steel, 40CrNiMoA, or other magnetically conductive materials. The magnetic conductor 150 is used to reduce the magnetic reluctance within the permanent magnet 130. The magnetic lines of force between the N and S poles within the permanent magnet 130 are connected through the magnetic conductor 150. This reduces the amount of permanent magnet 130 used while ensuring a high power factor for the motor and providing high resistance to demagnetization under high current. The permanent magnet 130 and the sheath 140 have an interference fit, while the magnetic conductor 150 and the permanent magnet 130 have a small clearance fit. The axial length of the magnetic conductor 150 is longer than that of the permanent magnet 130, while the length of the magnetic conductor 150 is shorter than that of the sheath 140. Furthermore, the outer circumference of the magnetic conductor 150 is a stepped rotor, with both ends extending into the first rotor shaft 100 and the second rotor shaft 110 for radial and axial positioning.

[0160] The first rotor shaft 100 and the second rotor shaft 110 of the present invention are both hollow thin-walled structures. The first rotor shaft 100 and the second rotor shaft 110 are both interference fits with the sheath 140. The first rotor shaft 100 and the second rotor shaft 110 are both transition fits or small clearance fits with the magnetic conductor 150.

[0161] The rotor structure of this invention can reduce the overall weight by about 30%, the rotor take-off speed by about 20%, greatly improve the friction start-stop life, and reduce the moment of inertia of the rotor structure by about 10%.

[0162] During rotor structure assembly, the first rotor shaft 100, permanent magnet 130, and second rotor shaft 110 of the rotor structure provided by this invention are first placed in a normal temperature environment at the assembly site. The magnetic conductive component 150 is placed in a low-temperature chamber at the assembly site for about two hours to allow it to shrink at low temperature. The sheath 140 is placed in a high-temperature chamber for about two hours to allow it to expand at high temperature. First, the low-temperature shrunk magnetic conductive component 150 is quickly installed into the first rotor shaft 100, and then the permanent magnet 130 is quickly put on. Next, the high-temperature sheath 140 is quickly taken out from the high-temperature chamber and put on the permanent magnet 130. Finally, the normal temperature second rotor shaft 110 is quickly installed into the sheath 140 to complete the assembly of the rotor structure.

[0163] The beneficial effects of this invention are: rotor weight can be reduced by approximately 30%, rotor take-off speed by approximately 20%, minimum rotor operating speed increased, and the range of operable speeds expanded. The approximately 20% reduction in rotor take-off speed significantly reduces dry friction at higher speeds, thereby effectively improving the start-stop life of the hydrodynamic gas bearing. Reducing rotor moment of inertia decreases the inverter's overcurrent multiple and rationally reduces high-speed motor torque, thus lowering the cost of the inverter and motor. The use of permanent magnet 130 is reduced by more than 50%, reducing the use of non-renewable resources and simultaneously reducing raw material costs.

[0164] In the description of this invention, the term "a plurality of" refers to two or more. Unless otherwise explicitly defined, the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and 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 of the invention. The terms "connection," "installation," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the terms in this invention can be understood according to the specific circumstances.

[0165] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0166] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rotor structure, characterized by, The rotor body comprises: a first rotor shaft, one end of which has a first opening; a second rotor shaft, one end of which has a second opening, the second opening being opposite to the first opening; a permanent magnet arranged between the first rotor shaft and the second rotor shaft, the permanent magnet being a cavity structure with two open ends, the two open ends of the permanent magnet being respectively in abutment with the open ends of the first rotor shaft and the second rotor shaft, and the two open ends of the permanent magnet being respectively in clearance fit with the first opening of the first rotor shaft and the second opening of the second rotor shaft; a magnetic conducting member arranged in the cavity of the permanent magnet; a sheath arranged around the first rotor shaft and the second rotor shaft and located outside the permanent magnet, the permanent magnet being capable of driving the sheath to rotate so that the first rotor shaft and the second rotor shaft rotate synchronously with the permanent magnet; the axial length of the magnetic conducting member is greater than the axial length of the permanent magnet; the rotor structure further comprises: positioning grooves arranged at the two ends of the magnetic conducting member respectively, the magnetic conducting member being clamped with the open ends of the first rotor shaft and the second rotor shaft through the positioning grooves respectively; the positioning grooves arranged on the magnetic conducting member comprise a first surface and a second surface, wherein the first surface is capable of being in contact with the inner wall surface of the first rotor shaft and the second rotor shaft, and the second surface is capable of being in contact with the end surface of the first opening of the first rotor shaft and the second opening of the second rotor shaft; a first mounting groove arranged on the outer surface of the first rotor shaft and extending axially to the open end of the first rotor shaft; a second mounting groove arranged on the outer surface of the second rotor shaft and extending axially to the open end of the second rotor shaft; the sheath is fixedly arranged in the first mounting groove and the second mounting groove; the sheath is in interference fit with the first mounting groove and the second mounting groove; the outer surface of the sheath is coplanar with the outer surfaces of the first rotor shaft and the second rotor shaft.

2. The rotor structure according to claim 1, wherein the first rotor shaft and the second rotor shaft are hollow structures.

3. The rotor structure according to claim 1, wherein the magnetic conducting member is configured as a cavity structure.

4. The rotor structure according to claim 1 or 2, wherein the sheath is in interference fit with the permanent magnet.

5. The rotor structure of claim 1 or 2, wherein the rotor structure further comprises: a first impeller; a first connecting shaft arranged on the side of the first rotor shaft away from the open end, the first connecting shaft being connected with the first impeller.

6. The rotor structure of claim 5, wherein the rotor structure further comprises: a thrust disc, the thrust disc being provided with a through hole for the first connecting shaft to pass through so as to be connected with the first impeller; a sealing ring arranged around the first connecting shaft and located between the first impeller and the thrust disc.

7. The rotor structure of claim 1 or 2, wherein the rotor structure further comprises: a second impeller; a second connecting shaft arranged on the side of the second rotor shaft away from the open end, the second connecting shaft being connected with the second impeller.

8. An electric machine characterized by the motor comprises: the rotor structure according to any one of claims 1 to 7.

9. A compressor characterized by, The compressor comprises: The motor of claim 8.

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