Compressor rotor and supporting arrangement structure

Abstract

The utility model relates to a compressor rotor and a supporting arrangement structure. The gear box comprises a gear box body, wherein a volute is arranged on the gear box body; the rotor assembly comprises a rotating shaft and an impeller connected with the rotating shaft, and an impeller backlash is formed between the impeller and the volute; a first dynamic pressure radial bearing, a transmission gear and a second dynamic pressure radial bearing are sequentially arranged on the rotating shaft in the direction close to the impeller. A first thrust disc and a second thrust disc are arranged at the positions, located at the two axial ends of the second dynamic pressure radial bearing, of the rotating shaft correspondingly. The position of the second thrust disc is close to the impeller relative to the first thrust disc, and the first thrust disc and the end face of the second dynamic pressure radial bearing form a main thrust bearing so as to bear the axial force, pointing to the impeller direction, of the rotor. According to the utility model, the influence of thermal elongation of the rotor on the impeller backlash is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a compressor technical field especially is a kind of compressor rotor and support arrangement structure. BACKGROUND

[0002] In prior art, the support of high-speed rotor of compressor using gear to increase speed uses two liquid dynamic pressure radial bearings and two dynamic pressure axial thrust bearings, one end of rotor is provided with impeller, the other end is provided with thrust disc, and one end face of one of radial bearings is formed into main thrust bearing (to bear the axial force of rotor) and upper end cover of gear box is formed into auxiliary thrust bearing. As shown in Figure 1 Because the distance L1 from the thrust surface of main thrust bearing to the clearance of impeller is very long (almost the length of entire rotor), so the thermal elongation of rotor is larger during working, especially for small specification compressor requiring smaller clearance of impeller (clearance 0.5~0.7mm), which greatly influences, and easily leads to mutual scratching of impeller and volute to damage impeller or even entire rotor. SUMMARY

[0003] Therefore, the utility model provides a kind of compressor rotor and support arrangement structure, reduce the influence of rotor thermal elongation to impeller clearance.

[0004] To solve the above technical problems, the utility model provides a kind of compressor rotor and support arrangement structure, including gear box body, gear box body is provided with:

[0005] Volute;

[0006] Rotor assembly, including rotating shaft and impeller connected with rotating shaft, impeller and volute form impeller clearance between them;

[0007] Wherein, first dynamic pressure radial bearing, transmission gear and second dynamic pressure radial bearing are sequentially arranged on the rotating shaft along the direction close to the impeller;

[0008] First thrust disc and second thrust disc are respectively arranged on the rotating shaft at the axial both ends of second dynamic pressure radial bearing;

[0009] The position of second thrust disc is close to impeller relative to first thrust disc, and the end face of first thrust disc and second dynamic pressure radial bearing forms main thrust bearing to bear the axial force of rotor pointing to the direction of impeller.

[0010] In an embodiment of the utility model, the first dynamic pressure radial bearing is radially extended with first clamping part, the gear box body is provided with first clamping groove, and the first clamping part is clamped with the first clamping groove.

[0011] In an embodiment of the utility model, the second dynamic pressure radial bearing has a second clamping part extending radially, the gear box body is provided with a second clamping groove, and first and second adjusting shims are respectively arranged between the axial ends of the second clamping part and the second clamping groove.

[0012] In an embodiment of the utility model, the rotating shaft is provided with a fastening component for fastening the impeller.

[0013] In an embodiment of the utility model, the impeller side gap is 0.5-0.7 mm.

[0014] In an embodiment of the utility model, the axial ends of the second dynamic pressure radial bearing form dynamic pressure thrust bearings with the first and second thrust discs respectively.

[0015] In an embodiment of the utility model, the first and second thrust discs are in an integral structure with the rotating shaft.

[0016] The above technical solution of the utility model has the following advantages compared with the prior art.

[0017] The compressor rotor and supporting arrangement structure has the advantages that the position of the axial support point (thrust bearing) of the rotor is adjusted, the distance from the thrust bearing to the impeller side gap is reduced, the influence of the thermal elongation of the rotor on the impeller side gap is reduced, the impeller and the volute are prevented from being scratched, the reliability of safe operation of the compressor is improved, and the structure is simple and the cost is low. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to make the content of the utility model more easily understood clearly, the utility model is further described in detail below according to the specific embodiments of the utility model and in combination with the drawings.

[0019] Figure 1 is a schematic diagram of a rotor supporting structure of the prior art.

[0020] Figure 2 is a schematic diagram of a compressor rotor and supporting arrangement structure of the utility model.

[0021] DESCRIPTION OF DRAWINGS

[0022] 1, gear box body;2, first dynamic pressure radial bearing;3, rotating shaft;31, transmission gear;32, first thrust disc;33, second thrust disc;4, second dynamic pressure radial bearing;5, adjusting assembly;51, first adjusting shim;52, second adjusting shim;6, impeller;7, fastening component;8, volute. DETAILED DESCRIPTION

[0023] The utility model makes further illustration to the utility model below combining with the drawings and specific embodiments, so that the person skilled in the art can better understand the utility model and can be implemented, but the embodiment is not as the limitation to the utility model.

[0024] In the utility model, if the direction (up, down, left, right, front and back) is described, it is only for the convenience of describing the technical scheme of the utility model, and is not indicative or suggestive of the technical features indicated must have a specific orientation, structure and operation in a specific orientation, therefore, it cannot be understood as a limitation of the utility model.

[0025] In the utility model, the meaning of "several" is one or more, and the meaning of "multiple" is two or more, "greater than", "less than", "exceeding" and the like are understood as not including the number; "above", "below", "within" and the like are understood as including the number. In the description of the utility model, if "first" and "second" are described, they are only used for distinguishing technical features for the purpose, and cannot be understood as indicative or suggestive of relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0026] In the utility model, unless otherwise explicitly limited, the words "set", "install", "connect" and the like should be broadly understood, for example, they can be directly connected, or indirectly connected through an intermediate medium; can be fixedly connected, or can be detachably connected, or can be integrally formed; can be mechanically connected, or can be electrically connected or capable of communicating with each other; can be the communication or interaction relationship between two elements inside or two elements. The person skilled in the art can reasonably determine the specific meaning of the above words in the utility model according to the specific content of the technical scheme.

[0027] Referring to Figure 2 The utility model discloses a kind of compressor rotor and support arrangement structure, including gear box 1, gear box 1 is provided with on the described gear box 1 is fixedly connected with:

[0028] Scroll case 8, with gear box 1 fixed connection;

[0029] Rotor assembly, including shaft 3 and the impeller 6 being connected with the shaft 3, the impeller 6 and the scroll case 8 form impeller side gap (x) between;The shaft 3 is provided with fastening component 7 that fastens the impeller 6 on the shaft 3;

[0030] Wherein, the shaft 3 is sequentially provided with first dynamic pressure radial bearing 2, transmission gear 31 and second dynamic pressure radial bearing 4 along the direction close to the impeller 6 on the shaft 3;

[0031] The shaft 3 is provided with first thrust disc 32 and second thrust disc 33 respectively on the axial both ends of the second dynamic pressure radial bearing 4 on the shaft 3;

[0032] The position of the second thrust disc 33 is close to the impeller 6 relative to the first thrust disc 32, and the first thrust disc 32 and the end face of the second dynamic pressure radial bearing 4 form a main thrust bearing to bear the axial force of the rotor pointing to the direction of the impeller 6.

[0033] In an embodiment, the first dynamic pressure radial bearing 2 radially extends a first clamping part, and the gear box 1 is provided with a first clamping groove, and the first clamping part is clamped with the first clamping groove.

[0034] In an embodiment, an adjusting assembly 5 is further provided to fine tune the axial position of the second dynamic pressure radial bearing 4.

[0035] Specifically, the adjusting assembly 5 includes a first adjusting gasket 51 and a second adjusting gasket 52, and the second dynamic pressure radial bearing 4 radially extends a second clamping part, and the gear box 1 is provided with a second clamping groove, and the first adjusting gasket 51 and the second adjusting gasket 52 are respectively arranged between the axial two ends of the second clamping part and the second clamping groove.

[0036] In an embodiment, the axial two ends of the second dynamic pressure radial bearing 4 respectively form dynamic pressure thrust bearings with the first thrust disc 32 and the second thrust disc 33.

[0037] In an embodiment, the first thrust disc 32 and the second thrust disc 33 are respectively integrated with the rotating shaft 3.

[0038] For small-sized compressors, the size of the impeller side gap is 0.5-0.7mm.

[0039] Referring to Figure 1 and Figure 2 As the total axial force of the rotor is to the right (pointing to the direction of the impeller 6), the thermal elongation of the distance L2 of the force bearing surface of the main thrust bearing to the impeller side gap is the influence on the length of the impeller side gap, that is, the thermal elongation amount Δ2=t•L2•ɑ, t—temperature rise, ɑ—linear expansion coefficient.

[0040] Since L2 is reduced by nearly half compared with L1 of the prior art, the elongation amount Δ2 is reduced by half compared with the elongation amount Δ1 of the prior art.

[0041] According to the experiment, Δ1=0.3-0.5mm, then Δ2=0.15-0.25mm, when x=0.5-0.7mm, even if the thermal elongation of the rotor is 0.25mm, the impeller side gap x is only reduced by 0.25mm, x=(0.5-0.7)-0.25=0.25-0.45mm, which avoids the scratching of the impeller 6 and the volute 8, and ensures the safety of the compressor operation.

[0042] Finally, it should be explained that the above specific embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the examples, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A compressor rotor and bearing arrangement, characterized by, The gear box (1) is provided with: A volute (8); A rotor assembly comprising a rotating shaft (3) and an impeller (6) connected to the rotating shaft (3), and a gap between the impeller (6) and the volute (8); Wherein, the rotating shaft (3) is provided with a first dynamic pressure radial bearing (2), a transmission gear (31) and a second dynamic pressure radial bearing (4) in sequence along the direction close to the impeller (6); The rotating shaft (3) is provided with a first thrust disc (32) and a second thrust disc (33) at the axial ends of the second dynamic pressure radial bearing (4) respectively; The position of the second thrust disc (33) is close to the impeller (6) relative to the first thrust disc (32), and the first thrust disc (32) and the end face of the second dynamic pressure radial bearing (4) form a main thrust bearing to bear the axial force of the rotor pointing to the direction of the impeller (6).

2. A compressor rotor and bearing arrangement according to claim 1, characterised in that, The first dynamic pressure radial bearing (2) has a first clamping part extending radially, and the gear box (1) is provided with a first clamping groove, and the first clamping part is clamped with the first clamping groove.

3. A compressor rotor and bearing arrangement according to claim 1, wherein, The second dynamic pressure radial bearing (4) has a second clamping part extending radially, and the gear box (1) is provided with a second clamping groove, and the axial ends of the second clamping part and the second clamping groove are respectively provided with a first adjusting pad (51) and a second adjusting pad (52).

4. A compressor rotor and bearing arrangement according to claim 1, wherein, The rotating shaft (3) is provided with a fastening part (7) for fastening the impeller (6).

5. A compressor rotor and bearing arrangement according to claim 1, wherein, The size of the impeller gap is 0.5-0.7mm.

6. A compressor rotor and bearing arrangement according to claim 1, wherein, The axial ends of the second dynamic pressure radial bearing (4) and the first thrust disc (32) and the second thrust disc (33) form a dynamic pressure thrust bearing.

7. A compressor rotor and bearing arrangement according to claim 1, wherein, The first thrust disc (32) and the second thrust disc (33) are respectively integrated with the rotating shaft (3).

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