Air cycle machine spindle assembly and air cycle machine

Abstract

The present application provides an air cycle machine main shaft assembly and an air cycle machine. The air cycle machine main shaft assembly includes a main shaft, on which an expansion impeller, a compression impeller and a fan blade are sequentially arranged; a first bearing, supporting the main shaft and located between the expansion impeller and the compression impeller; an inner diameter D1 of the first bearing, in the axial direction of the main shaft, a distance L1 between the center position of the first bearing and the root of the compression impeller, L1 / D1 is 1.6 to 2.4; a second bearing, supporting the main shaft and located between the compression impeller and the fan blade; an inner diameter D2 of the second bearing, in the axial direction of the main shaft, a distance L2 between the center position of the second bearing and the root of the compression impeller, L2 / D2 is 3.1 to 4.1. The support position of the bearing is limited to ensure that the vibration at the support position is reduced or even zero, the destructiveness to the bearing is low, and the bearing reliability is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of air cycle machines, and in particular relates to an air cycle machine main shaft assembly and an air cycle machine. Background Art

[0002] An air cycle machine is a compressed air circulation refrigeration system that uses air as a working fluid. It generally includes a turbine compressor and an expander to realize the compression and expansion processes respectively. At the same time, the system also requires a fan to realize convection heat exchange. Gas expansion outputs work, while gas compression and fan air supply require work. Therefore, the air cycle machine uses the gas expansion work to compress gas and blower air to achieve energy saving.

[0003] The specific structure of the air cycle machine mainly includes a rotor system component and a stationary component, wherein the bearing system supports the main shaft component, and the main shaft component rotates at high speed. In the traditional main shaft component, since multiple rotating parts are arranged on the shaft at the same time, and the corresponding effects are different, such as compression and expansion, the main shaft component is prone to radial vibration, which damages the bearing, generates noise and shortens the service life. Summary of the invention

[0004] Therefore, the present application provides an air cycle machine main shaft assembly and an air cycle machine, which can solve the problem in the prior art that the main shaft assembly generates vibrations that damage the bearings and affect the service life.

[0005] In order to solve the above problems, the present application provides an air cycle machine main shaft assembly, comprising:

[0006] A main shaft, on which an expansion impeller, a compression impeller and a fan blade are sequentially arranged;

[0007] A first bearing supports the main shaft and is located between the expansion impeller and the compression impeller; the inner diameter D1 of the first bearing is such that in the axial direction of the main shaft, the distance L1 between the center position of the first bearing and the root of the compression impeller is such that L1 / D1 is 1.6 to 2.4;

[0008] The second bearing supports the main shaft and is located between the compression impeller and the fan blade; the inner diameter D2 of the second bearing is axially of the main shaft, and the distance L2 between the center position of the second bearing and the root of the compression impeller is 3.1 to 4.1.

[0009] Optionally, the first bearing and the second bearing both have a length W in the axial direction of the main shaft, and D1 = D2 = D, and W / D is 0.8-1.2.

[0010] Optionally, L1 / D1 is 1.8 to 2.2.

[0011] Optionally, L1 / D1 is 2.0.

[0012] Optionally, L2 / D2 is 3.3-3.9.

[0013] Optionally, L2 / D2 is 3.5.

[0014] Optionally, a thrust plate is provided on the main shaft, and the bearing support assembly further includes a thrust bearing for clamping the thrust plate; the thrust plate is located close to one end of the first bearing or the second bearing.

[0015] Optionally, the thrust plate is disposed between the expansion impeller and the first bearing.

[0016] According to still another aspect of the present application, an air cycle machine is provided, comprising the air cycle machine main shaft assembly as described above.

[0017] The present application provides an air cycle machine main shaft assembly, comprising: a main shaft, on which an expansion impeller, a compression impeller and a fan blade are sequentially arranged; a first bearing, supporting the main shaft and being located between the expansion impeller and the compression impeller; an inner diameter D1 of the first bearing, in the axial direction of the main shaft, a distance L1 between the center position of the first bearing and the root of the compression impeller, and L1 / D1 is 1.6 to 2.4; a second bearing, supporting the main shaft and being located between the compression impeller and the fan blade; an inner diameter D2 of the second bearing, in the axial direction of the main shaft, a distance L2 between the center position of the second bearing and the root of the compression impeller, and L2 / D2 is 3.1 to 4.1.

[0018] Limiting the support position of the bearing supporting the main shaft of the air cycle machine can ensure that the bearing is at the vibration node of the main shaft. In this way, the vibration borne by the bearing is greatly reduced or even zero, making the vibration generated by the high-speed rotation of the main shaft less destructive to the bearing, thereby improving the reliability of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of an air cycle machine according to an embodiment of the present application;

[0020] Figure 2 This is a schematic structural diagram of a spindle assembly according to an embodiment of the present application;

[0021] Figure 3 It is an external schematic diagram of an air cycle machine according to an embodiment of the present application;

[0022] Figure 4 A schematic diagram of the relative change of the vibration of the first bearing setting position according to an embodiment of the present application;

[0023] Figure 5A schematic diagram of the relative change of the vibration of the second bearing setting position in an embodiment of the present application;

[0024] Figure 6 Schematic diagram of the modal vibration shape of the main shaft assembly according to an embodiment of the present application.

[0025] The reference numerals are:

[0026] 1. Main shaft; 11. Expansion impeller; 12. Compression impeller; 121. Root; 13. Fan blade; 14. Thrust plate; 15. Thrust bearing; 16. Axial positioning member; 2. First bearing; 21. First center line; 3. Second bearing; 31. Second center line. DETAILED DESCRIPTION

[0027] See also Figures 1 to 5 As shown, according to an embodiment of the present application, an air cycle machine main shaft assembly includes:

[0028] A main shaft 1, on which an expansion impeller 11, a compression impeller 12 and a fan blade 13 are sequentially arranged;

[0029] A first bearing 2 supports the main shaft 1 and is located between the expansion impeller 11 and the compression impeller 12; an inner diameter D1 of the first bearing 2, and a distance L1 between the center position of the first bearing 2 and the root of the compression impeller 12 in the axial direction of the main shaft 1, where L1 / D1 is 1.6 to 2.4;

[0030] The second bearing 3 supports the main shaft 1 and is located between the compression impeller 12 and the fan blade 13; the inner diameter D2 of the second bearing 3 is in the axial direction of the main shaft 1, and the distance L2 between the center position of the second bearing 3 and the root 121 of the compression impeller 12, L2 / D2 is 3.1~4.1.

[0031] Since the expansion impeller 11, compression impeller 12 and fan blade 13 are sequentially arranged on the main shaft 1 of the air cycle machine, and the main shaft 1 is a high-speed running component, combined with the radial force of the expansion impeller 11, compression impeller 12 and fan blade 13 on the main shaft 1, the main shaft 1 itself will undergo a change in modal vibration, including deformation of the main shaft 1 part in the radial direction, such as the main shaft 1 bulges in the middle and bends downward at both ends, and there will be two vibration nodes at different positions. If the first bearing 2 and the second bearing 3 supporting the main shaft 1 are not arranged at the positions of the two vibration nodes, the main shaft 1 and the two bearings will inevitably vibrate, resulting in large friction power consumption and shortened product life.

[0032] like Figure 6The modal vibration shape diagram of the main shaft assembly of the air cycle machine shown in the figure shows the first-order modal vibration shape of the main shaft assembly, in which there are two vibration shape nodes, namely the two intersection points of the mesh deformation and the horizontally placed main shaft 1. When the main shaft assembly vibrates according to the first-order modal formation, the vibration of these two intersection points is zero. According to the knowledge of vibration theory, within the design speed range, the structural vibration deformation of the main shaft assembly is mainly composed of a linear combination of rigid body vibration and the first-order modal vibration shape. Therefore, a bearing is arranged at the position of each vibration shape node, the vibration of the main shaft assembly is less destructive to the bearing, and the reliability of the bearing is higher.

[0033] The present application combines the vibration mode nodes of the main shaft 1, and arranges the first bearing 2 and the second bearing 3 at the positions of the vibration mode nodes on the main shaft 1 to support the main shaft 1. At this time, the radial vibration of the main shaft 1 is minimized or even zero, so that the radial vibration generated by the high-speed rotation of the main shaft 1 is greatly reduced in its destructiveness to the bearing, thereby improving the reliability of the bearing, thereby reducing noise and increasing the service life.

[0034] For the central position of the first bearing 2 or the second bearing 3 in the axial direction of the main shaft 1, as shown in FIG. Figure 1 As shown, it refers to the midpoint of the projected length of each bearing in the axial direction. Correspondingly, the center lines passing through this midpoint and perpendicular to the axial direction are: the first center line 21 and the second center line 31; and the compression impeller 12 itself includes a root 121, which refers to the intersection position of the blade and the hub.

[0035] In some embodiments, the lengths of the first bearing 2 and the second bearing 3 in the axial direction of the main shaft 1 are both W, and D1 = D2 = D, and W / D is 0.8-1.2.

[0036] In the traditional structure, the structural parameters of the first bearing 2 and the second bearing 3, including the axial length and the inner diameter, are the same, while in this application, the W / D of the two bearings is limited to a range: W / D is 0.8 to 1.2. If the value is greater than this range, the reliability deteriorates and the friction power consumption is too large; if the value is less than this range, the bearing capacity is insufficient.

[0037] In some embodiments, L1 / D1 of the first bearing 2 is 1.8-2.2; more preferably, L1 / D1 is 2.0.

[0038] And, L2 / D2 of the second bearing 3 is 3.3-3.9; more preferably, L2 / D2 is 3.5.

[0039] The supporting positions of the first bearing 2 and the second bearing 3 on the main shaft 1 are further limited so that the vibration effect on the two bearings during high-speed rotation of the main shaft 1 assembly will be smaller or even zero, which will be more conducive to improving the reliability of the bearings, reducing noise and increasing the service life.

[0040] Corresponding detection is performed on the vibrations generated when the first bearing 2 and the second bearing 3 are in different positions, and the details are described as follows.

[0041] When L1 / D=2.0, L2 / D=3.5, the vibration at the first bearing 2 is A01 (m / s 2 ), the vibration at the second bearing 3 is A02 (m / s 2 ).

[0042] like Figure 4 As shown, when L2 / D=3.5, when L1 / D=1.2, 1.6, 2.0, 2.4, 2.8, the vibration A1 (m / s 2 ) relative to A01(m / s 2 )’s relative values ​​A1 / A01 are 3.50, 1.5, 1.0, 1.22 and 2.42 respectively.

[0043] like Figure 5 As shown, when L1 / D is fixed at 2.0, and L2 / D is set to 2.5, 3.1, 3.5, 4.1, and 4.5, respectively, the vibration A2 (m / s 2 ) relative to A02(m / s 2 )’s relative values ​​A2 / A02 are 4.62, 1.63, 1.0, 1.4 and 3.21 respectively.

[0044] In some embodiments, a thrust plate 14 is provided on the main shaft 1 , and the bearing support assembly further includes a thrust bearing 15 for clamping the thrust plate 14 ; the thrust plate 14 is located close to one end of the first bearing 2 or the second bearing 3 .

[0045] Usually, a thrust plate 14 is also provided on the main shaft 1 to limit the axial movement of the main shaft 1; in the present application, the thrust plate 14 is arranged close to one end of the first bearing 2 or the second bearing 3, and the thrust plate 14 is clamped by the thrust bearing 15, so that the axial movement of the main shaft 1 assembly can be controlled, thereby improving the stability of the operation of the main shaft 1 assembly.

[0046] In some embodiments, a thrust plate 14 is disposed between the expansion impeller 11 and the first bearing 2 .

[0047] The thrust plate 14 is arranged between the expansion impeller 11 and the first bearing 2, especially at a position close to the first bearing 2. This optimal solution takes into account both the placement of the first bearing 2 near the minimum vibration and the expansion and refrigeration process of the expansion impeller 11, and can effectively remove the friction heat of the thrust bearing 15 by means of structural heat transfer.

[0048] According to still another aspect of the present application, an air cycle machine is provided, comprising the air cycle machine main shaft assembly as described above.

[0049] like Figure 3 The air cycle machine shown is used in a compressed air refrigeration system. The rotational power of the main shaft 1 comes from the expansion work of the gas. After the gas flows into T01, it expands and does work. The temperature of the gas after the work is reduced, and the low-temperature gas flows out from T02 and is transported to the area that needs refrigeration. The expansion work drives the main shaft 1 to rotate. The compression impeller 12 on the main shaft 1 sucks the gas from C01, and after being compressed by the compression impeller 12, it is discharged from C02. At the same time, the fan blade 13 on the main shaft 1 sucks air from F01 and discharges it at F02 to drive the air.

[0050] like Figure 2 As shown, the expansion impeller 11, the thrust plate 14, the compression impeller 12, the axial positioning member 16, the fan blade 13, etc. are sequentially sleeved on the main shaft 1; the first bearing 2 is mounted between the thrust plate 14 and the compression impeller 12, and the second bearing 3 is mounted between the axial positioning member 16 and the fan blade 13, thereby limiting the radial movement of the main shaft 1, and the thrust plate 14 is clamped by the leg bearing, as shown in FIG. Figure 1 As shown, the limitation of the axial movement of the main shaft 1 is thus achieved.

[0051] It is easy for those skilled in the art to understand that the above-mentioned implementation modes can be freely combined and superimposed without conflict.

[0052] The above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. An air cycle machine main shaft assembly, characterized in that: include: A main shaft (1), wherein an expansion impeller (11), a compression impeller (12) and a fan blade (13) are sequentially arranged on the main shaft (1); a first bearing (2), supporting the main shaft (1) and located between the expansion impeller (11) and the compression impeller (12); an inner diameter D1 of the first bearing (2); and a distance L1 between a center position of the first bearing (2) and a root (121) of the compression impeller (12) in the axial direction of the main shaft (1), wherein L1 / D1 is 1.6 to 2.4; The second bearing (3) supports the main shaft (1) and is located between the compression impeller (12) and the fan blade (13); the inner diameter D2 of the second bearing (3) is such that, in the axial direction of the main shaft (1), the distance L2 between the center position of the second bearing (3) and the root (121) of the compression impeller (12) is 3.1 to 4.

1.

2. The air cycle machine main shaft assembly according to claim 1, characterized in that: The first bearing (2) and the second bearing (3) both have a length W in the axial direction of the main shaft (1), and D1 = D2 = D, with W / D being 0.8 to 1.

2.

3. The air cycle machine main shaft assembly according to claim 1 or 2, characterized in that: The L1 / D1 is 1.8 to 2.

2.

4. The air cycle machine main shaft assembly according to claim 3, characterized in that: The L1 / D1 is 2.

0.

5. The air cycle machine main shaft assembly according to claim 1 or 2, characterized in that: The L2 / D2 is 3.3 to 3.

9.

6. The air cycle machine main shaft assembly according to claim 1 or 2, characterized in that: The L2 / D2 is 3.

5.

7. The air cycle machine main shaft assembly according to claim 1, characterized in that: The main shaft (1) is provided with a thrust plate (14), and the main shaft assembly of the air cycle machine further comprises a thrust bearing (15) for clamping the thrust plate (14); the thrust plate (14) is located close to one end of the first bearing (2) or the second bearing (3).

8. The air cycle machine main shaft assembly according to claim 7, characterized in that: The thrust plate (14) is arranged between the expansion impeller (11) and the first bearing (2).

9. An air cycle machine, characterized in that: The invention comprises an air cycle machine main shaft assembly as claimed in any one of claims 1 to 8.

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