Bearing arrangement, electric air compressor, dynamic balancing method and assembly method

Abstract

The invention relates to a bearing structure (22) for a rotor assembly (1) of an electric air compressor, the rotor assembly (1) comprising a rotor shaft (11) and a bearing portion (12) arranged on the rotor shaft (11), the bearing structure (22) forming a thrust bearing in cooperation with the bearing portion (12), the bearing structure (22) comprising a first axial section (221) corresponding to the bearing portion (12) and a second axial section (222) axially adjacent to the first axial section (221), the second axial section (222) being separable from the first axial section (221), and the second axial section (222) being configured to be assembled radially around the rotor shaft (11). The invention also relates to an electric air compressor, a dynamic balancing method and an assembly method. The invention has the advantage that the rotor assembly (1) does not need to be disassembled after dynamic balancing for installing the bearing structure (22) and the wear during dynamic balancing is reduced.

Description

Technical Field

[0001] This invention relates to a bearing structure for a rotor assembly of an electric air compressor (EAC), an electric air compressor including a bearing structure, a method for dynamic balancing of a rotor assembly for an electric air compressor, and a method for assembling an electric air compressor. Background Technology

[0002] In EAC (Electrical Adjustment) systems, the rotor speed is very high (typically above 100,000 rpm), thus requiring dynamic balancing. A rotor generally consists of a rotor shaft and an impeller, with the impeller typically fixed to the rotor shaft using shims and nuts. The rotor shaft and impeller can be dynamically balanced individually on a balancing machine. However, even with the best possible machining precision, the shims and nuts may not achieve the required dynamic balance after assembly. Therefore, after assembling the impeller onto the rotor shaft using shims and nuts, the entire rotor needs to be dynamically balanced.

[0003] However, the following problem exists: After dynamic balancing, when assembling the entire EAC, since the bearing structure, which together with the bearing section on the rotor shaft forms the thrust bearing, is located between the impeller and the bearing section, it is necessary to disassemble the impeller of the dynamically balanced rotor, then fit the bearing structure between the impeller and the bearing section onto the rotor shaft, and finally reassemble the impeller. However, the dynamic balance of the entire rotor will be greatly affected by the disassembly and reassembly of the impeller. Summary of the Invention

[0004] The purpose of this invention is to provide a bearing structure for a rotor assembly of an electric air compressor and a method for dynamic balancing of a rotor assembly of an electric air compressor, which eliminates the need for impeller disassembly and reassembly and minimizes wear during dynamic balancing.

[0005] According to a first aspect of the invention, a bearing structure for a rotor assembly of an electric air compressor is provided, wherein the rotor assembly includes at least a rotor shaft and a bearing portion disposed on the rotor shaft, the bearing structure and the bearing portion together forming a thrust bearing for the rotor assembly, the bearing structure including a first axial segment corresponding to the bearing portion and at least one second axial segment axially adjacent to the first axial segment, the second axial segment being configured to be separable from the first axial segment, and the second axial segment being configured to be assembled around the rotor shaft in a radial direction.

[0006] According to an alternative embodiment of the invention, the second axial segment includes at least two axial segment portions, which are independent of each other or connected in a manner that allows them to pivot relative to each other.

[0007] According to an alternative embodiment of the invention, the second axial segment is configured to be fixed on the first axial segment.

[0008] According to an alternative embodiment of the invention, the first axial segment is configured to form a thrust bearing for the rotor assembly with the bearing portion.

[0009] According to an optional embodiment of the present invention, the bearing structure is a bearing plate.

[0010] According to an optional embodiment of the invention, the thrust bearing is an air thrust bearing.

[0011] According to an alternative embodiment of the invention, the rotor assembly includes an impeller disposed on the rotor shaft, and the second axial section is configured to fill the gap between the first axial section and the impeller.

[0012] According to an optional embodiment of the invention, the minimum axial dimension of the portion of the second axial segment that fills the gap is selected to be greater than the maximum axial movement dimension of the rotor assembly during dynamic balancing.

[0013] According to an alternative embodiment of the invention, the rotor assembly includes a nut and a washer for mounting the impeller onto the rotor shaft.

[0014] According to a second aspect of the present invention, an electric air compressor comprising the aforementioned bearing structure is provided.

[0015] According to a third aspect of the present invention, a method for dynamic balancing of a rotor assembly for an electric air compressor is provided, wherein the rotor assembly includes at least a rotor shaft and a bearing portion disposed on the rotor shaft, and the bearing structure of the electric air compressor and the bearing portion form a thrust bearing for the rotor assembly. During dynamic balancing of the rotor assembly, at least a portion of the bearing structure is pre-assembled onto the rotor assembly and held in a manner that does not contact the rotor assembly.

[0016] According to an optional embodiment of the invention, during the dynamic balancing of the rotor assembly, only a portion of the bearing structure is pre-assembled on the rotor assembly and held in a manner that does not contact the rotor assembly.

[0017] According to a fourth method of the present invention, a method for assembling an electric air compressor is provided, wherein the electric air compressor includes at least a rotor assembly and a bearing structure, the rotor assembly including at least a rotor shaft and a bearing portion disposed on the rotor shaft, the bearing structure and the bearing portion forming a thrust bearing for the rotor assembly. Prior to assembling the electric air compressor, during dynamic balancing of the rotor assembly, at least a portion of the bearing structure is pre-assembled onto the rotor assembly and held in a manner that does not contact the rotor assembly. During assembly of the electric air compressor, the rotor assembly is directly assembled with the at least a portion of the bearing structure pre-assembled onto the rotor assembly.

[0018] According to an optional embodiment of the present invention, before assembling the electric air compressor, during the dynamic balancing of the rotor assembly, only a portion of the bearing structure is pre-assembled on the rotor assembly and held in a manner that does not contact the rotor assembly; and during the assembly of the electric air compressor, the rotor assembly is directly assembled with the portion of the bearing structure pre-assembled on the rotor assembly.

[0019] According to an optional embodiment of the present invention, when assembling the electric air compressor, the remaining part of the bearing structure is first assembled with the part of the bearing structure to form a complete bearing structure without disassembling the rotor assembly, and then the rotor assembly is directly assembled with the complete bearing structure.

[0020] The positive effects of this invention are as follows: By performing dynamic balancing with the bearing structure, the rotor assembly and bearing structure can be assembled as a unit for the EAC after dynamic balancing, so that the assembly of the EAC does not affect the dynamic balance of the rotor assembly. In order to prevent high-pressure gas leakage on the impeller side and to meet the requirements of the air thrust bearing of the EAC, the clearance between the bearing structure and the bearing part and the impeller is very small. Therefore, when performing dynamic balancing with the entire bearing structure, large wear may occur due to the axial movement of the rotor assembly. However, through the special design of the second axial section of this invention, the rotor assembly can be dynamically balanced with only the first axial section, thereby minimizing wear during dynamic balancing. Attached Figure Description

[0021] The invention will now be described in more detail with reference to the accompanying drawings, which will provide a better understanding of its principles, features, and advantages. The drawings include:

[0022] Figure 1 An example of the rotor assembly and bearing structure of EAC is shown.

[0023] Figure 2 An example of the bearing structure of the present invention is shown.

[0024] Figure 3 The rotor assembly is shown in a partial view, with only the first axial section being dynamically balanced.

[0025] Figure 4 A partial view shows the second axial segment being fixed to the first axial segment after dynamic balancing. Detailed Implementation

[0026] To make the technical problems to be solved, the technical solutions, and the beneficial technical effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and several exemplary embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0027] Figure 1 An example of a rotor assembly 1 and bearing structure 22 of an EAC is shown. The rotor assembly 1 is rotatably supported within the housing of the EAC, for example. The rotor assembly 1 includes a rotor shaft 11 and a bearing portion 12 disposed on the rotor shaft 11. A rotor 111 is disposed within the rotor shaft 11. The rotor 111 interacts, for example, with a stator (not shown) arranged within the housing of the EAC. The bearing portion 12 is part of a thrust bearing for the rotor assembly 1. Here, the bearing portion 12 is mounted on the rotor shaft 11. However, it is also conceivable that the bearing portion 12 may be integrally constructed with the rotor shaft 11, for example. The rotor shaft 11 may also be constructed with a disc 16, for example, protruding radially from the rotor shaft 11. The bearing structure 22, together with the bearing portion 12, forms a thrust bearing for the rotor assembly 1. The thrust bearing here is exemplarily an air thrust bearing. The bearing structure 22 is configured, for example, to be suitable for mounting on the housing of the EAC. The rotor assembly 1 also includes, for example, an impeller 13, which is mounted on the rotor shaft 11, for example, by means of a nut 14 and a washer 15. Obviously, other assembly methods can also be envisioned, such as welding, force-locking, form-locking, and / or material-locking connections. Here, the clearances between the bearing structure 22 and the impeller 13, as well as between the bearing structure 22 and the bearing portion 12, are designed to be very small. This prevents high-pressure air from leaking in through the clearances on the impeller side, while also meeting the high dimensional requirements of the air thrust bearing on the bearing portion side. Dynamic balancing of the entire rotor assembly 1 is required.

[0028] exist Figure 2An example of a bearing structure 22 for a rotor assembly 1 of an electric air compressor according to the present invention is shown. The bearing structure 22 is, for example, a bearing plate and includes a first axial segment 221 corresponding to a bearing portion 12 and a second axial segment 222 axially adjacent to the first axial segment 221. The second axial segment 222 is configured to be separable from the first axial segment 221. As shown, the first axial segment 221 is exemplary a single annular plate, while the second axial segment 222 is also an annular plate and is exemplary divided into two equally spaced axial segment portions 2221 at 180° fan angles. These two axial segment portions 2221 are, for example, independent of each other, whereby the two axial segment portions 2221 can be joined radially to surround the rotor shaft 11. Obviously, it is also conceivable that the second axial segment 222 is divided into more axial segment portions 2221 or into axial segment portions 2221 with different fan angles.

[0029] According to an exemplary embodiment of the invention (not shown), the second axial segment 222 includes at least two axial segment portions 2221 connected in a manner pivotally connected relative to each other. The at least two axial segment portions 2221 are pivotally combined to surround the rotor shaft 11 in a radial direction.

[0030] According to an exemplary embodiment of the invention, the second axial segment 222 is configured to be fixed to the first axial segment 221. The second axial segment 222 can be fixed to the first axial segment 221 by means of fasteners, such as screws, or by means of form locking, force locking, and / or material locking. However, it is also conceivable that the second axial segment can be directly mounted on the housing of the EAC.

[0031] According to an exemplary embodiment of the present invention, the first axial segment 221 is configured to form with the bearing portion 12 a thrust bearing, such as an air thrust bearing, for the rotor assembly 1.

[0032] According to an exemplary embodiment of the invention, the second axial segment 222 is configured to fill the gap between the first axial segment 221 and the impeller 13. In the ECA-assembled state, the second axial segment 222, for example, at least partially and to the maximum extent fills the gap between the first axial segment 221 and the impeller 13 (see...). Figure 1 This is to prevent high-pressure gas from leaking into the area where the rotor 111 and stator are located through the gap. The second axial section 222 may also participate in the formation of the thrust bearing in a small part or even not participate in the formation of the thrust bearing at all.

[0033] According to an exemplary embodiment of the present invention, the minimum axial dimension of the portion of the second axial segment 222 that fills the gap is selected to be greater than the maximum axial movement dimension of the rotor assembly 1 during dynamic balancing. Therefore, without dynamic balancing with the second axial segment 222, the rotor assembly 1 will not come into contact with the first axial segment 221, thereby reducing wear during dynamic balancing.

[0034] The present invention also relates to a method for dynamic balancing of a rotor assembly 1 for an electric air compressor, wherein the rotor assembly 1 includes at least a rotor shaft 11 and a bearing portion 12 disposed on the rotor shaft 11, and a bearing structure 22 of the electric air compressor forms a thrust bearing for the rotor assembly 1 with the bearing portion 12. In the method, during dynamic balancing of the rotor assembly 1, at least a portion of the bearing structure 22 is pre-assembled on the rotor assembly 1 and held in a manner that does not contact the rotor assembly 1.

[0035] According to an exemplary embodiment of the present invention, during dynamic balancing of the rotor assembly 1, only a portion of the bearing structure 22 is pre-assembled onto the rotor assembly 1 and held in a manner that does not contact the rotor assembly 1. This portion is, for example, the first axial segment 221 of the bearing structure 22, see [link to relevant documentation]. Figure 3 Here, the portion of the first axial section 221 directly sandwiched between the impeller 13 and the bearing portion 12 can, for example, be centrally held between the impeller 13 and the bearing portion 12. It is also conceivable that, during dynamic balancing of the rotor assembly 1, the entire bearing structure 22 is pre-assembled on the rotor assembly 1 and held in a manner that does not contact the rotor assembly 1.

[0036] The present invention also relates to a method for assembling an electric air compressor, wherein the electric air compressor includes at least a rotor assembly 1 and a bearing structure 22, the rotor assembly 1 including at least a rotor shaft 11 and a bearing portion 12 disposed on the rotor shaft 11, and the bearing structure 22 and the bearing portion 12 forming a thrust bearing for the rotor assembly 1. In the method, before assembling the electric air compressor, during dynamic balancing of the rotor assembly 1, at least a portion of the bearing structure 22 is pre-assembled onto the rotor assembly 1 and held in a manner that does not contact the rotor assembly 1. During the assembly of the electric air compressor, the rotor assembly 1 is directly assembled with the at least a portion of the bearing structure 22 pre-assembled onto the rotor assembly 1.

[0037] According to an exemplary embodiment of the present invention, before assembling the electric air compressor, during dynamic balancing of the rotor assembly 1, only a portion of the bearing structure 22 is pre-assembled onto the rotor assembly 1 and held in a manner that does not contact the rotor assembly 1; during assembly of the electric air compressor, the rotor assembly 1 is assembled directly with the pre-assembled portion of the bearing structure 22 attached to it. This portion is specifically the first axial section 221 of the bearing structure 22.

[0038] According to an exemplary embodiment of the present invention, when assembling an electric air compressor, the remaining portion of the bearing structure 22, particularly the second axial segment 222, is first assembled with the portion of the bearing structure 22, particularly the first axial segment 221, into a complete bearing structure 22 without disassembling the rotor assembly 1. Specifically, the two axial segment portions 2221 of the second axial segment 222 are assembled radially around the rotor shaft 11 and fixed to the first axial segment 221, see [reference needed]. Figure 4 Then, the rotor assembly 1 is directly assembled into the electric air compressor with the complete bearing structure 22. However, fixing the second axial section to the first axial section is not necessary. For example, it is conceivable that the second axial section 222 can be directly fixed and installed using a receiving part provided in the housing of the EAC.

[0039] Although specific embodiments of the invention have been described in detail herein, they are given for illustrative purposes only and should not be construed as limiting the scope of the invention. Various substitutions, alterations, and modifications can be conceived without departing from the spirit and scope of the invention.

[0040] List of reference numerals

[0041] 1 Rotor assembly

[0042] 11 Rotor shaft

[0043] 111 Rotor

[0044] 12 Bearing section

[0045] 13 Impeller

[0046] 14 Nuts

[0047] 15 gaskets

[0048] 16 Frisbees

[0049] 22 Bearing Structure

[0050] 221 First Axial Section

[0051] 222 Second Axial Section

[0052] 2221 Axial section

Claims

1. A method for dynamic balancing of a rotor assembly (1) for an electric air compressor, wherein, The electric air compressor includes a bearing structure (22) for the rotor assembly (1), wherein, The rotor assembly (1) includes at least a rotor shaft (11) and a bearing portion (12) disposed on the rotor shaft (11), wherein the bearing structure (22) and the bearing portion (12) together form a thrust bearing for the rotor assembly (1). The bearing structure (22) includes: - The first axial segment (221) corresponding to the bearing portion (12) is an integral annular plate, and - At least one second axial segment (222) axially adjacent to the first axial segment (221), the second axial segment (222) being configured to be separable from the first axial segment (221), and the second axial segment (222) being configured to be assembled radially around the rotor shaft (11). The rotor assembly (1) includes an impeller (13) disposed on the rotor shaft (11), and the second axial section (222) is configured to fill the gap between the first axial section (221) and the impeller (13). In the method, when the rotor assembly (1) is dynamically balanced, only the first axial segment of the bearing structure (22) is pre-assembled on the rotor assembly (1) and held in a manner that does not contact the rotor assembly (1).

2. The method for dynamic balancing of the rotor assembly (1) for an electric air compressor according to claim 1, wherein, The second axial segment (222) includes at least two axial segment portions (2221), which are independent of each other or connected in a manner that allows them to pivot relative to each other; and / or The second axial segment (222) is configured to be fixed to the first axial segment (221); and / or The first axial segment (221) is configured to form a thrust bearing for the rotor assembly (1) with the bearing portion (12); and / or The bearing structure (22) is a bearing plate; and / or The thrust bearing is an air thrust bearing.

3. The method for dynamic balancing of the rotor assembly (1) for an electric air compressor according to claim 1 or 2, wherein, The minimum axial dimension of the portion of the second axial segment (222) filling the gap is selected to be greater than the maximum axial movement dimension of the rotor assembly (1) during dynamic balancing; and / or The rotor assembly (1) includes a nut (14) and a washer (15) for mounting the impeller (13) onto the rotor shaft (11).

4. A method for assembling an electric air compressor, wherein, The electric air compressor Includes a bearing structure (22) for the rotor assembly (1), wherein, The rotor assembly (1) includes at least a rotor shaft (11) and a bearing portion (12) disposed on the rotor shaft (11), wherein the bearing structure (22) and the bearing portion (12) together form a thrust bearing for the rotor assembly (1). The bearing structure (22) includes: - The first axial segment (221) corresponding to the bearing portion (12) is an integral annular plate, and - At least one second axial segment (222) axially adjacent to the first axial segment (221), the second axial segment (222) being configured to be separable from the first axial segment (221), and the second axial segment (222) being configured to be assembled radially around the rotor shaft (11). The rotor assembly (1) includes an impeller (13) disposed on the rotor shaft (11), and the second axial section (222) is configured to fill the gap between the first axial section (221) and the impeller (13). In this method, Before assembling the electric air compressor, during the dynamic balancing of the rotor assembly (1), only the first axial section of the bearing structure (22) is pre-assembled on the rotor assembly (1) and held in a manner that does not contact the rotor assembly (1); When assembling the electric air compressor, the rotor assembly (1) is assembled directly with the first axial section of the bearing structure (22) pre-assembled on the rotor assembly (1).

5. The method for assembling an electric air compressor according to claim 4, wherein, When assembling the electric air compressor, the second axial section of the bearing structure (22) and the first axial section of the bearing structure (22) are first assembled into a complete bearing structure (22) without disassembling the rotor assembly (1). Then, the rotor assembly (1) is directly assembled with the complete bearing structure (22) in the electric air compressor.

6. The method for assembling an electric air compressor according to claim 4 or 5, wherein, The second axial segment (222) includes at least two axial segment portions (2221), which are independent of each other or connected in a manner that allows them to pivot relative to each other; and / or The second axial segment (222) is configured to be fixed to the first axial segment (221); and / or The first axial segment (221) is configured to form a thrust bearing for the rotor assembly (1) with the bearing portion (12); and / or The bearing structure (22) is a bearing plate; and / or The thrust bearing is an air thrust bearing.

7. The method for assembling an electric air compressor according to claim 4 or 5, wherein, The minimum axial dimension of the portion of the second axial segment (222) filling the gap is selected to be greater than the maximum axial movement dimension of the rotor assembly (1) during dynamic balancing; and / or The rotor assembly (1) includes a nut (14) and a washer (15) for mounting the impeller (13) onto the rotor shaft (11).

Images