CN216742131U

CN216742131U - Air cycle machine

Info

Publication number: CN216742131U
Application number: CN202121433690.1U
Authority: CN
Inventors: 陈云飞; 符渡; 刘茂龙; 黄建平; 于艳翠
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2021-06-24
Filing date: 2021-06-24
Publication date: 2022-06-14
Anticipated expiration: 2031-06-24

Abstract

The utility model provides an air cycle machine, which comprises a compressor and a turbine, wherein the compressor and the turbine share a rotating shaft, and the air cycle machine also comprises a bearing seat assembly, the bearing seat assembly comprises a bearing seat, the bearing seat is sleeved on the outer peripheral side of the rotating shaft, the axial first side of the bearing seat is connected with a compressor volute of the compressor, the axial second side of the bearing seat is connected with a turbine volute of the turbine, and a sealing element is further arranged on the axial first side of the bearing seat. According to the utility model, the heat transfer between the compressor and the turbine can be effectively reduced, the heat insulation performance is improved, on the other hand, the middle section of the rotating shaft can be effectively supported, and the rotating reliability of the rotating shaft is ensured; at the same time, the sealing element on one side of the compressor can improve the sealing between the compressor and the turbine.

Description

Air cycle machine

Technical Field

The utility model belongs to the technical field of air conditioning, and particularly relates to an air cycle machine.

Background

The air cycle machine utilizes the expansion of air in the turbine to do work externally to realize gas cooling, and drives the compressor and the fan to rotate. The compressor, fan and turbine belong to typical three-wheel air cycle machine, and its characteristic is that three wheels are coaxial. The air flows into the next stage along one part, enters the compressor, enters the next stage of turbine after being pressurized and heated by the compressor, and works on the expansion of the gas through the turbine to realize the reduction of the temperature. In the related art, in order to prevent the gas from moving between the adjacent compressor and turbine, a sealing plate is disposed between the compressor and the turbine, and the sealing plate increases the resistance to the gas flow, so as to achieve sealing. However, the sealing plate of the related art has a low thickness, and thus, the sealing property and the heat insulating property thereof are not sufficient.

SUMMERY OF THE UTILITY MODEL

Therefore, the utility model provides an air cycle machine which can overcome the defects of low sealing performance and heat insulation performance between a compressor and a turbine in the related art.

In order to solve the above problems, the present invention provides an air cycle machine, including a compressor, a turbine, a rotating shaft shared by the compressor and the turbine, and a bearing seat assembly, where the bearing seat assembly includes a bearing seat, the bearing seat is sleeved on an outer circumferential side of the rotating shaft, an axial first side of the bearing seat is connected to a compressor volute of the compressor, an axial second side of the bearing seat is connected to a turbine volute of the turbine, and a sealing member is further provided on the axial first side of the bearing seat.

In some embodiments, the seal has a seal portion surrounding the shaft, a proximal side of the seal portion forming a radial gap with the shaft.

In some embodiments, the seal portion includes a plurality of raised rings spaced apart along an axial direction of the shaft, a top portion of the raised rings forming the radial gap with the shaft.

In some embodiments, the sealing element is a ring-shaped element, and in the axial section of the sealing element, the convex ring is trapezoidal, the upper base of the trapezoid is close to the rotating shaft, and the lower base of the trapezoid is far away from the rotating shaft; and/or a groove is formed between two adjacent convex rings, and the connecting part of the groove and the convex ring is rounded.

In some embodiments, the trapezoid is a right angle trapezoid.

In some embodiments, the right trapezoid has a height H, an included angle α between the hypotenuse and the upper base, a length B of the upper base, an axial distance D between two adjacent collars (32), and a radial width δ — 0.2312+1.6875H-0.015 α -0.75B + 0.1875D.

In some embodiments, the radial gap δ is 0.2 mm.

In some embodiments, 1mm H.ltoreq.1.5 mm, 90 DEG < alpha.ltoreq.120 DEG, 0.2mm B.ltoreq.0.5 mm, 0.7mm D.ltoreq.2 mm.

In some embodiments, H is 1.2mm, α is 107.5 °, B is 0.3mm, and D is 1.3 mm.

In some embodiments, the seal further has a connecting portion surrounding an outer side of the sealing portion, a side of the connecting portion remote from the bearing seat having an orientation boss; and/or a connecting hole is formed on the connecting part.

According to the air cycle machine provided by the utility model, the bearing seat and the sealing element connected with the bearing seat are arranged on the bearing seat assembly, so that on one hand, the axial distance between the compressor and the turbine can be enlarged (the heat insulation thickness is increased), the heat transfer between the compressor and the turbine can be effectively reduced, the heat insulation performance is improved, on the other hand, the middle section of the rotating shaft can be effectively supported, and the rotation reliability of the rotating shaft is ensured; at the same time, the sealing element on one side of the compressor can improve the sealing between the compressor and the turbine.

Drawings

FIG. 1 is a schematic illustration of an air cycle machine according to an embodiment of the present invention (turbine, etc. components omitted);

FIG. 2 is a schematic view (axial section) of the internal structure of FIG. 1;

FIG. 3 is a perspective view of the seal of FIG. 2;

FIG. 4 is an axial cross-sectional view of FIG. 3;

FIG. 5 is an enlarged view of a portion of FIG. 4 at A;

FIG. 6 is a graph of leakage versus shaft speed for a seal employing the present invention versus a prior art rectangular tooth type seal, where the abscissa is shaft speed (in r/min) and the ordinate is leakage (kg/s);

FIG. 7 is a graph of leakage versus differential pressure for a seal employing the present invention versus a prior art seal of the rectangular tooth type, where the abscissa is the gas differential pressure (in 10 units)²Kpa), the ordinate is the leakage (kg/s).

The reference numerals are represented as:

1. a compressor; 11. a compressor volute; 12. a compressor diffuser; 21. a bearing seat; 3. a seal member; 31. a sealing part; 32. a convex ring; 33. a groove; 34. a connecting portion; 35. orienting the boss; 36. connecting holes; 4. a fan; 100. a rotating shaft.

Detailed Description

Referring to fig. 1 to 7 in combination, according to an embodiment of the present invention, there is provided an air cycle machine, including a compressor 1, a turbine (not shown in the drawings), a fan 4, a rotating shaft 100 shared by the compressor 1, the turbine and the fan 4, and a bearing seat assembly, the bearing seat assembly includes a bearing seat 21, the bearing seat 21 is sleeved on an outer periphery side of the rotating shaft 100, an axial first side of the bearing seat 21 is connected with a compressor volute 11 of the compressor 1, an axial second side of the bearing seat 21 is connected with a turbine volute of the turbine, a seal 3 is further provided on the axial first side of the bearing seat 21, it can be understood that, the axial first side is a side of the bearing seat 21 facing the compressor volute 11, and the axial second side is a side of the bearing seat 21 facing the turbine volute, therefore, the compressor volute 11 and the turbine volute are connected into a whole through the bearing seat 21, and a bearing (not shown in the figure) arranged between the bearing seat 21 and the rotating shaft 100 can also improve the sealing performance to a certain extent. In the technical scheme, the bearing seat 21 of the bearing seat assembly and the sealing element 3 connected with the bearing seat 21 can enlarge the axial distance between the compressor 1 and the turbine (increase the heat insulation thickness), so that the heat transfer between the compressor 1 and the turbine can be effectively reduced, the heat insulation performance is improved, and on the other hand, the middle section of the rotating shaft 100 can be effectively supported, so that the rotation reliability of the rotating shaft 100 is ensured; at the same time, the sealing element 3 on one side of the compressor 1 can improve the sealing between the compressor 1 and the turbine.

The sealing element 3 may be an independent component, which is detachably connected to the bearing seat 21, so that the sealing element 3 can be conveniently maintained, and of course, the sealing element 3 may also be integrally formed with the bearing seat 21, so that the sealing element 3 can be more conveniently replaced during maintenance, and the assembling process of the sealing element 3 is facilitated. It can be understood that the bearing seat 21 and the sealing element 3 should be made of a material having low heat insulation and density, for example, the sealing element 3 may be made of a carbon alloy material (e.g., forged blank 6a 02).

The sealing element 3 is provided with a sealing part 31 surrounding the rotating shaft 100, and a radial gap is formed between the near-axis side of the sealing part 31 and the rotating shaft 100, so that the sealing element 3 is in non-contact fit with the rotating shaft 100, the problem of friction and wear caused by high-speed rotation of the rotating shaft 100 is avoided, and the sealing reliability is improved.

In some embodiments, the sealing portion 31 includes a plurality of protruding rings 32 spaced along the axial direction of the rotating shaft 100, the radial gap is formed between the top of the protruding ring 32 and the rotating shaft 100, and the plurality of protruding rings 32 spaced along the axial direction of the rotating shaft 100 can weaken the airflow flow rate in the pressure source multiple times, so as to realize a labyrinth seal. A groove 33 is formed between two adjacent convex rings 32, and the connecting part of the groove 33 and the convex ring 32 is provided with a rounding to prevent stress concentration at the joint of the groove 33 and the convex ring 32. For example, the radius of the radius is R, 0.2mm ≦ R ≦ 0.5 mm.

Along with the increase of pressure difference, labyrinth seal's leakage quantity also can increase, and the leakage quantity of triangle-shaped shape is the biggest, and rectangular leakage quantity is then compare triangle-shaped shape and will be little, on the basis of rectangular seal, improves rectangular seal into trapezium structure, can increase the complexity of fluid flow channel, increases the circulation resistance of fluid, and then further improves sealed effect. That is, the sealing member 3 is a ring-shaped member, and in the axial cross section of the sealing member 3, the protruding ring 32 has a trapezoidal shape, the upper base of the trapezoidal shape is close to the rotating shaft 100, and the lower base of the trapezoidal shape is far from the rotating shaft 100. Preferably, the trapezoid is a right-angled trapezoid. Further, the height of the right trapezoid is H, the included angle between the oblique side and the upper base is α, the length of the upper base is B, the axial distance between two adjacent convex rings 32 is D, the radial width of the radial gap is δ (i.e., the unilateral thickness of the annular gap), δ is-0.2312 +1.6875H-0.015 α -0.75B +0.1875D, it is explicitly stated that, in this formula, H, B, D is a value corresponding to a corresponding physical quantity in mm units, α is a value corresponding to a corresponding physical quantity in ° units, after the design of H, B, D and α is determined, the respective units of dimensions are unified to mm or ° and then the respective corresponding specific values are substituted into the formula, preferably, 1mm or more, H or less than 1.5mm, 90 ° < α or less than 120.2 mm or less, B or less than 0.5mm, and 0.7mm or less than D2 mm. Preferably, H is 1.2mm, α is 107.5 °, B is 0.3mm, and D is 1.3mm, with the corresponding radial gap δ yielding δ of about 0.2mm, preferably 0.2 mm.

Based on the right-angle trapezoidal seal 3 having H of 1.2mm, α of 107.5 °, B of 0.3mm, D of 1.3mm and δ of 0.2mm, the radial clearance is preferably 0.2mm, and the inventors conducted comparative experimental studies on the amount of leakage thereof and the rectangular tooth type labyrinth seal.

Under the condition of keeping the pressure difference unchanged, the rotating speed of the rotating shaft 100 is increased from 30000r/min to 60000r/min, the leakage amount of the two seals is slightly reduced, and specifically as shown in fig. 6, it can be seen that the leakage amount of the rectangular tooth type seal in the prior art is reduced from 0.226kg/s to 0.201kg/s, while the leakage amount of the right-angle trapezoid seal in the present invention is reduced from 0.213kg/s to 0.192kg/s, and the leakage amount of the seal in the present invention is always better than that of the rectangular tooth type seal in the prior art along with the increase of the rotating speed. As shown in FIG. 7, the maximum leakage amount of the sealing element in the present application is 0.324kg/s, while the maximum leakage amount of the sealing element in the prior art with rectangular teeth is 0.426kg/s, so that the sealing element in the present application has small leakage amount and better sealing effect. And because the sealing member 3 of the application is applied to the large pressure difference between the compressor and the turbine, the sealing performance of the sealing member adopting the application is better.

In some embodiments, the sealing element 3 further has a connecting portion 34 surrounding the outer side of the sealing portion 31, and a side of the connecting portion 34 away from the bearing seat 21 has an orientation boss 35, that is, a side of the orientation boss 35 facing the compressor turbine, which serves to define the installation direction.

The connecting portion 34 is provided with a plurality of connecting holes 36, the connecting holes 36 are provided in plural, and the plurality of connecting holes 36 are arranged (arrayed) around the sealing portion 31 at an axial interval, so that the sealing member 3 is more uniformly stressed in all directions when assembled with the bearing seat 21 through corresponding bolts, thereby ensuring the radial uniformity of the radial gap between the sealing portion 31 and the rotating shaft 100 and the circumferential uniformity of the sealing performance, for example, 8 connecting holes 36 are provided, and the central angle formed by two adjacent connecting holes 36 and the center of the sealing member 3 is 45 °.

In some embodiments, a compressor diffuser 12 is further disposed in the compressor volute 11, the compressor diffuser 12 is connected (e.g., bolted) to the first axial side of the bearing seat 21, and the compressor diffuser 12 is disposed around the outer circumference of the sealing member 3.

It is readily understood by a person skilled in the art that the advantageous ways described above can be freely combined, superimposed without conflict.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. The air cycle machine comprises a compressor (1) and a turbine, wherein the compressor (1) and the turbine share a rotating shaft (100), and is characterized by further comprising a bearing seat assembly, the bearing seat assembly comprises a bearing seat (21), the bearing seat (21) is sleeved on the outer peripheral side of the rotating shaft (100), the axial first side of the bearing seat (21) is connected with a compressor volute (11) of the compressor (1), the axial second side of the bearing seat (21) is connected with a turbine volute of the turbine, and a sealing element (3) is further arranged on the axial first side of the bearing seat (21).

2. The air cycle machine of claim 1, wherein the seal (3) has a seal portion (31) surrounding the rotating shaft (100), a radial gap being formed between a proximal side of the seal portion (31) and the rotating shaft (100).

3. The air cycle machine of claim 2, wherein the seal portion (31) includes a plurality of raised rings (32) spaced axially along the shaft (100), the radial gap being formed between a top of the raised rings (32) and the shaft (100).

4. An air cycle machine according to claim 3, characterized in that the sealing element (3) is a ring-shaped element, and in the axial cross-section of the sealing element (3), the protruding ring (32) is trapezoidal, the upper base of the trapezoid being close to the rotation axis (100) and the lower base of the trapezoid being far from the rotation axis (100); and/or a groove (33) is formed between two adjacent convex rings (32), and the connecting part of the groove (33) and the convex ring (32) is rounded.

5. The air cycle machine of claim 4, wherein the trapezoid is a right angle trapezoid.

6. The air cycle machine of claim 5, wherein the right trapezoid has a height H, a hypotenuse angled at an angle α to the upper base, a length B of the upper base, an axial separation D between two adjacent raised rings (32), and a radial width δ -0.2312+1.6875H-0.015 α -0.75B +0.1875D of the radial gap.

7. The air cycle machine of claim 6, wherein δ is 0.2 mm.

8. The air cycle machine of claim 6, wherein H is 1mm ≦ 1.5mm, α is 90 ° < 120 °, B is 0.2mm ≦ 0.5mm, and D is 0.7mm ≦ 2 mm.

9. The air cycle machine of claim 8, wherein H-1.2 mm, α -107.5 °, B-0.3 mm, and D-1.3 mm.

10. An air cycle machine according to claim 2, characterized in that the seal (3) further has a connecting portion (34) surrounding the outside of the sealing portion (31), the side of the connecting portion (34) remote from the bearing seat (21) having an orientation boss (35); and/or the connecting part (34) is provided with a connecting hole (36).