Rotor assembly for air compressor and air compressor

Abstract

The utility model relates to a rotor assembly for an air compressor, and the rotor assembly at least comprises a rotor which is provided with a rotating shaft located at a first axial end part, and the rotating shaft is configured to be suitable for being connected with an impeller of the air compressor in an anti-torque manner; the flying disc is located at a second axial end portion, opposite to the first axial end portion, of the rotor and extends outwards in the radial direction in the mode of being coaxial with the rotor. The utility model further relates to a corresponding air compressor. The disturbance during rotation can be reduced or eliminated, the operation stability of the air compressor is effectively improved, and the service life is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of air compressors, in particular to a rotor assembly for air compressors. The utility model also relates to a corresponding air compressor. Background Art

[0002] An air compressor is a device that increases air pressure by compressing air and has a variety of structural types, among which a centrifugal air compressor accelerates the air using a high-speed rotating impeller and compresses the air by converting kinetic energy into potential energy, wherein the impeller is driven by the rotor of the air compressor, and the rotor rotates under the action of the magnetic field generated by the energized stator. Specifically, when the impeller rotates at a high speed, the high-pressure air driven by the rotation of the impeller is thrown out radially, and a negative pressure space is formed in the front area of ​​the impeller to attract air to flow to the impeller continuously. However, due to the pressure difference before and after the impeller, an axial force acting on the rotor is generated, and the axial force points to the front area of ​​the impeller and causes axial displacement and wear of the rotor.

[0003] At present, in order to offset or balance the axial force generated by the rotation of the impeller, a flying disc is arranged at a position of the rotor close to the impeller, and the flying disc generates a force in the opposite direction to the axial force during the rotation of the rotor. However, the center of gravity of the rotor constructed in this way is offset toward the impeller in the axial direction, so that the rotor will be disturbed when rotating at a high speed and may cause serious wear of the radial bearing used to support the rotor, thereby adversely affecting the operating stability of the air compressor. Utility Model Content

[0004] Therefore, the purpose of the utility model is to provide an improved rotor assembly for an air compressor, through which the disturbance during rotation can be reliably reduced or eliminated, effectively improving the operating stability of the air compressor and extending its service life. In addition, the utility model also relates to a corresponding air compressor.

[0005] According to a first aspect of the utility model, a rotor assembly for an air compressor is provided, wherein the rotor assembly at least comprises:

[0006] a rotor having a rotation shaft at a first axial end, the rotation shaft being adapted to be connected to the impeller of the air compressor in a rotationally fixed manner; and

[0007] A flying disc is located at a second axial end of the rotor opposite the first axial end and extends outwardly in a radial direction in a coaxial manner with the rotor.

[0008] Compared with the prior art, in the rotor assembly according to the utility model, the rotating shaft of the rotor for torsionally connecting with the impeller is located at the first axial end, and the flying disc is located at the second axial end of the rotor, and the second axial end is opposite to the first axial end in the axial direction. Therefore, when the rotor assembly is assembled in the air compressor, the impeller and the flying disc are respectively located at the axial ends of the rotor, so that the common center of gravity of the rotor assembly and the impeller is located in the middle position of the rotor, which can reduce or eliminate the disturbance of the rotor when rotating at high speed and avoid wear of the radial bearing as much as possible, thereby effectively improving the operating stability of the air compressor and extending the service life.

[0009] According to a second aspect of the present utility model, an air compressor is provided, wherein the air compressor at least comprises:

[0010] - a housing and a volute and an end cover respectively arranged on both sides of the housing, wherein the housing is hollow cylindrical;

[0011] - a stator arranged in said housing;

[0012] - According to the rotor assembly of the present invention, the rotor of the rotor assembly is at least partially surrounded by the stator and is rotatably supported relative to the stator via a radial bearing; and

[0013] an impeller which is arranged in the volute and is connected in a rotationally fixed manner to the shaft of rotation of the rotor,

[0014] A receiving cavity is formed between the shell and the end cover, and the flying disc of the rotor assembly is arranged in the receiving cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be described in more detail below with reference to the accompanying drawings, so that the principles, features and advantages of the present invention can be better understood. The accompanying drawings include:

[0016] Figure 1 A schematic cross-sectional view of an air compressor according to an exemplary embodiment of the present invention is shown;

[0017] Figure 2a and Figure 2b Schematic cross-sectional views of rotor assemblies for air compressors according to different exemplary embodiments of the present invention are respectively shown. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and a number of exemplary embodiments.

[0019] It should be understood that, in this document, the expressions "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance, nor should they be understood as implicitly indicating the number of technical features indicated. Features defined as "first" or "second" may explicitly or implicitly indicate that at least one of the features is included.

[0020] In this specification, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate, or the internal communication of two elements. For ordinary technicians in this field, the meanings of the above terms in this disclosure can be understood according to the circumstances.

[0021] Figure 1 A schematic cross-sectional view of an air compressor 100 according to an exemplary embodiment of the present invention is shown. Figure 2a and Figure 2b Schematic cross-sectional views of rotor assemblies 50 for air compressors 100 according to different exemplary embodiments of the present invention are shown. In this case, the air compressor 100 is particularly configured as a centrifugal electric air compressor.

[0022] like Figure 1 As shown, the air compressor 100 includes a housing 10 and a volute 20 and an end cover 30 respectively arranged on both sides of the housing 10 in the axial direction X. Here, the housing 10 is constructed in a hollow cylindrical shape, so that there is a receiving space for the stator 40 and the rotor assembly 50 inside the housing 10, wherein the housing 10 is particularly constructed in a multi-piece manner and, for example, bearing side plates 11 are respectively provided on both sides of the axial direction, and the bearing side plates are respectively fixedly connected to the volute 20 and the end cover 30, for example, by bolts or clamps. Here, the volute 20 has an air inlet 21 open in the axial direction X and an air outlet 22 located radially outside to guide the air flow to be discharged radially outward from the center, and the end cover 30 is configured to close the end side opening of the housing 10 away from the air inlet 21.

[0023] like Figure 1 As shown, the air compressor 100 includes a stator 40, which is arranged in a receiving space in the housing 10, wherein the stator 40 has a stator core formed by laminating silicon steel sheets and a stator winding wound in slots of the stator core, and the stator winding is connected to a three-phase AC power supply through a lead guide. When powered on, a rotating magnetic field is generated by the stator 40, and the rotating magnetic field drives the rotor to rotate.

[0024] like Figure 1 and Figure 2aAs shown, the air compressor 100 includes a rotor assembly 50, which includes a rotor 51, which is at least partially surrounded by a stator 40, so that the rotor 51 can rotate relative to the stator 40 under the action of a rotating magnetic field generated by the stator 40, wherein the rotor 51 is rotatably supported by a radial bearing 12, which is fixedly arranged on the housing 10, especially on the bearing side plate 11 and is configured to bear a load in a radial direction Y, wherein the rotor 51 has a first axial end 1 and a second axial end 2 opposite to each other in an axial direction X, wherein the rotor 51 is provided with a rotating shaft 3 at the first axial end 1, and the rotating shaft is configured to output the rotating motion of the rotor 51 outward. Here, the rotor assembly 50 also has a flying disc 52, which is located at the second axial end 52 of the rotor 51 and extends outward in the radial direction Y in a coaxial manner with the rotor 51, wherein the flying disc 52 is arranged in a receiving cavity surrounded by the housing 10 and the end cover 30, and the receiving cavity can be formed by a side recess of the end cover 30, for example. However, it is also possible that the receiving cavity is formed by the housing 10, for example, by the undercut of the bearing side plate 11, or by the undercut of the end cover 30 and the undercut of the housing 10. In particular, the rotor assembly 50 is rotationally symmetrically configured to minimize vibration of the rotor assembly 50 during rotation.

[0025] like Figure 1 and Figure 2a As shown, the air compressor 100 includes an impeller 60, which is arranged in the volute 20 and is connected to the rotating shaft 3 at the first axial end 1 of the rotor 51 in a torsionally fixed manner, so that the rotational movement of the rotor 51 can be transmitted to the impeller 60 through the rotating shaft 3, wherein the impeller 60 is fixedly connected to the rotating shaft 3 in a form-locking manner, for example, by a key and a keyway or a thread. When the impeller 60 rotates at a high speed, a negative pressure is formed at the air inlet 21 of the volute 20, and the negative pressure draws external air in through the air inlet 21. The inflowing air is accelerated by the impeller 60 and finally flows outward in the radial direction Y through the air outlet 22. Here, the pressure on the side of the impeller 60 facing the air inlet 21 is significantly less than the pressure on the other side of the impeller 60 facing away from the air inlet 21, so that an axial force toward the air inlet 21 is generated as a whole, and the axial force is transmitted to the rotor 51 through the impeller 60. At the same time, the flying disc 52 rotating together with the rotor 51 can generate a force in the opposite direction to the axial force generated by the impeller 60 , which can balance or offset the axial force and avoid an unexpected deviation of the axial position of the rotor 51 .

[0026] like Figure 1 and Figure 2aAs shown, viewed along the axial direction X, the impeller 60 and the flying disc 52 are respectively arranged at the first axial end 1 and the second axial end 2 of the rotor 51, so that the common center of gravity of the rotor assembly 50 and the flying disc 52 is located at the middle position of the rotor 51, thereby effectively reducing the vibration of the rotor 51 during rotation and avoiding the wear of the radial bearing 12.

[0027] For example, Figure 1 As shown, the air compressor 100 also includes a thrust bearing 70, which is arranged on the side of the housing 10, especially the bearing side plate 11, facing the end cover 30 in a receiving cavity surrounded by the housing 10 and the end cover 30, wherein there is an air gap between the thrust bearing 70 and the flying disc 52. When the rotor assembly 50 rotates, the thrust bearing 70 can work together with the flying disc 52 to form an axial force directed away from the impeller 60, thereby better balancing or offsetting the axial force generated by the impeller 60.

[0028] For example, Figure 1 As shown, the rotor 51 is supported by two radial bearings 12 spaced apart from each other in the axial direction X, the two radial bearings are respectively arranged on the bearing side plates 11 on both sides of the housing 10 and are configured to bear the load from the rotor 51 in the radial direction Y, wherein the two radial bearings 12 are arranged so that the common center of gravity of the rotor assembly 50 and the impeller 60 is located at the center of the two radial bearings 12. In this way, the radial bearings 12 can be subjected to force evenly as much as possible and the wear of the radial bearings 12 can be reduced.

[0029] Exemplarily, a guide portion is provided on the flying disc 52, and the guide portion can cooperate with the thrust bearing 70 to guide the flow of air in the air gap between the flying disc 52 and the thrust bearing 70 and increase the force generated away from the first axial end 1 when the flying disc 52 rotates, thereby better balancing or offsetting the axial force generated by the impeller 60. In particular, the guide portion of the flying disc 52 is provided on the side of the first axial end 1 of the flying disc 52 facing the rotor 51. However, it is also possible that the guide portion is provided on the periphery of the flying disc 52.

[0030] For example, Figure 2b As shown, at least one adjusting inner hole 4 is provided in the rotor 51, through which the center of gravity position of the rotor assembly 50 along the axial direction X can be adjusted, thereby the center of gravity of the rotor assembly 50 and the impeller 60 can be adjusted more flexibly and accurately. Here, multiple adjusting inner holes 4 can also be provided in the rotor 51 as required. In particular, the rotor 51 can have multiple sections, which are assembled together in a detachable manner, wherein the adjusting inner hole 4 can be provided at the radial center of the section.

[0031] For example, Figure 2a and Figure 2b As shown, the rotor 51 can be constructed integrally with the flying disk 52, which can simplify the assembly steps of the rotor assembly 50. However, it is also possible that the rotor 51 and the flying disk 52 are constructed separately and are fixedly connected to each other, for example, by screws.

[0032] The above explanation of the embodiments only describes the present invention within the framework of the examples. Of course, as long as it makes sense technically, the individual features of the embodiments can be freely combined with each other without departing from the framework of the present invention.

[0033] Other advantages and alternative embodiments of the present invention are obvious to those skilled in the art. Therefore, the present invention in its broader sense is not limited to the specific details, representative structures and exemplary embodiments shown and described. On the contrary, those skilled in the art can make various modifications and substitutions without departing from the basic spirit and scope of the present invention.

Claims

1. A rotor assembly (50) for an air compressor (100), characterized in that: The rotor assembly (50) comprises at least: - a rotor (51) having a rotation shaft (3) at a first axial end (1), the rotation shaft (3) being configured to be suitable for being connected to an impeller (60) of the air compressor (100) in a rotationally fixed manner; and a flying disc (52) which is located at a second axial end (2) of the rotor (51) opposite the first axial end (1) and which extends outwardly in a radial direction (Y) in a coaxial manner with the rotor (51).

2. The rotor assembly (50) according to claim 1, characterized in that The rotor (51) and the flying disc (52) are constructed in one piece; or The rotor (51) and the flying disc (52) are constructed separately and are fixedly connected to each other.

3. The rotor assembly (50) according to claim 1 or 2, characterized in that: At least one adjusting inner hole (4) is provided in the rotor (51) to adjust the center of gravity position of the rotor assembly (50) along the axial direction (X); and / or The rotor (51) has a plurality of sections which are assembled together in a detachable manner.

4. The rotor assembly (50) according to claim 1 or 2, characterized in that: A guide portion is provided on the flying disc (52), and the guide portion is configured to generate a force that deviates from the first axial end portion (1) when the flying disc (52) rotates.

5. The rotor assembly (50) according to claim 4, characterized in that The air guide portion is arranged on a side surface of the first axial end portion (1) of the flying disc (52) facing the rotor (51) and / or on a peripheral edge of the flying disc (52).

6. The rotor assembly (50) according to claim 1 or 2, characterized in that: The rotor assembly (50) is rotationally symmetrically constructed.

7. An air compressor (100), characterized in that: The air compressor (100) comprises at least: - a housing (10) and a volute (20) and an end cover (30) respectively arranged on both sides of the housing (10), wherein the housing (10) is of hollow cylindrical configuration; - a stator (40) arranged in the housing (10); - A rotor assembly (50) according to any one of claims 1 to 5, wherein the rotor (51) of the rotor assembly (50) is at least partially surrounded by the stator (40) and is rotatably supported relative to the stator (40) via a radial bearing (12); and an impeller (60) which is arranged in the volute (20) and is connected to the shaft (3) of the rotor (51) in a rotationally fixed manner, A receiving cavity is formed between the housing (10) and the end cover (30), and a flying disc (52) of the rotor assembly (50) is arranged in the receiving cavity.

8. The air compressor (100) according to claim 7, characterized in that: The air compressor (100) further includes a thrust bearing (70) which is arranged on a side of the housing (10) facing the end cover (30) and is configured to form an axial force directed away from the impeller (60) together with the flying disc (52) when the rotor assembly (50) rotates.

9. The air compressor (100) according to claim 7 or 8, characterized in that: The rotor (51) is supported by two radial bearings (12) spaced apart from each other in the axial direction (X), and the two radial bearings (12) are arranged so that the common center of gravity of the rotor assembly (50) and the impeller (60) is located at the center of the two radial bearings (12).

10. The air compressor (100) according to claim 7 or 8, characterized in that: The receiving cavity is formed by a side recess of the housing (10) and / or a side recess of the end cover (30).

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