Air cycle machine

Abstract

The invention provides an air cycle machine which comprises a transmission shaft, an annular sealing piece and an impeller, the impeller is installed at one end of the transmission shaft, an annular protrusion is formed on the outer circumferential wall of the transmission shaft and is close to the impeller, an annular groove is formed in the inner circumferential wall of the annular sealing piece, and the annular sealing piece is arranged on the periphery of the transmission shaft in a sleeving mode. And the annular bulge is inserted into the annular groove. According to the invention, the annular bulge designed on the outer circumferential wall of the transmission shaft is inserted into the annular groove formed in the inner circumferential wall of the annular sealing element, so that the annular bulge and the annular groove are closely matched, and the sealing performance between the annular sealing element and the transmission shaft is better; strong flowing obstruction is generated on airflow flowing along the outer surface of the transmission shaft, so that the leakage amount of high-pressure air from the impeller can be reduced, and finally the leakage amount of the air circulation machine is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of air cycle machine design, and in particular relates to an air cycle machine. Background Art

[0002] An air cycle unit (ACU) is a subcomponent of an air compression refrigeration system. It uses a compressor and turbine to perform the compression and expansion processes, respectively. The system also requires a fan to drive air to remove heat from the heat exchanger. The compressor, turbine, and fan impeller form a rotor assembly, which is supported by an air bearing system for high-speed rotation. Because the fan impeller is located near ambient pressure, while the internal pressure of the ACU is approximately 3-4 bara, the pressure differential causes high-pressure gas to flow to the fan impeller and be discharged to the outside. This can cause gas leakage from the ACU. Excessive leakage can affect the unit's performance and even operational stability. The current solution involves installing a seal on the ACU's drive shaft. However, because the ACU's rotor assembly is a high-speed moving component, with speeds reaching approximately 60,000 rpm, a non-contact seal is used between the seal and the drive shaft. However, this non-contact seal allows gas to leak through the gap between the seal and the drive shaft, resulting in poor sealing effectiveness. Summary of the Invention

[0003] Therefore, the present invention provides an air cycle machine, which can solve the technical problem that the non-contact seal between the transmission shaft and the sealing element of the existing air cycle machine is used, resulting in poor sealing effect.

[0004] In order to solve the above problems, the present invention provides an air cycle machine, including a transmission shaft, an annular seal and an impeller, the impeller being mounted at one end of the transmission shaft, an annular protrusion being formed on the outer peripheral wall of the transmission shaft, the annular protrusion being close to the impeller, an annular groove being constructed on the inner peripheral wall of the annular seal, the annular seal being sleeved on the periphery of the transmission shaft, and the annular protrusion being inserted into the annular groove.

[0005] In some embodiments, a plurality of annular protrusions are formed on the outer circumferential wall of the transmission shaft, and each of the annular protrusions is distributed at intervals along the axial direction of the transmission shaft. A plurality of annular grooves are constructed on the inner circumferential wall of the annular seal, and each of the annular grooves is distributed at intervals along the axial direction of the annular seal. Each of the annular protrusions is respectively inserted into each of the annular grooves.

[0006] In some embodiments, the annular protrusion is inserted into the annular groove, and a gap is formed between an inner circumferential wall of the annular seal and an outer circumferential wall of the transmission shaft.

[0007] In some embodiments, a distance H between an inner circumferential wall of the annular seal and an outer circumferential wall of the transmission shaft is 0.3 mm ≤ H ≤ 0.4 mm.

[0008] In some embodiments, the annular seal includes two separate parts, which are butt-jointed and assembled to form the annular seal.

[0009] In some embodiments, the outer periphery of the transmission shaft is provided with a volute, the annular seal and the impeller are both located in the volute, and the outer peripheral wall of the annular seal is sealingly connected to the inner peripheral wall of the volute.

[0010] In some embodiments, the annular seal includes an annular inner layer and an annular outer layer, the annular groove is constructed on the inner circumferential wall of the annular inner layer, the annular inner layer is made of a flexible material, the annular outer layer is made of a hard material, and the annular outer layer is interference fit with the volute.

[0011] In some embodiments, a sealing ring is sleeved on the outer peripheral wall of the annular seal, and the sealing ring is clamped between the outer peripheral wall of the annular seal and the inner peripheral wall of the volute.

[0012] In some embodiments, an annular groove is configured on the outer peripheral wall of the annular seal, and the sealing ring is partially inserted into the annular groove.

[0013] In some embodiments, a stopper is provided on the outer periphery of the transmission shaft, the stopper is located between the annular seal and the impeller, and the stopper forms a stop for the annular seal along the axial direction of the transmission shaft.

[0014] The air circulation machine provided by the present invention has the following beneficial effects:

[0015] The annular protrusion designed on the outer peripheral wall of the transmission shaft is inserted into the annular groove constructed on the inner peripheral wall of the annular seal, so that a close fit is formed between the annular protrusion and the annular groove, and a good sealing is achieved between the annular seal and the transmission shaft, which produces a strong flow resistance to the airflow flowing along the outer surface of the transmission shaft, thereby reducing the leakage of high-pressure gas from the impeller, and ultimately reducing the leakage of the air cycle machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0017] Figure 1 is a schematic diagram of an air cycle machine according to an embodiment of the present invention;

[0018] Figure 2 for Figure 1 A is an enlarged schematic diagram;

[0019] Figure 3 This is a schematic diagram of an annular seal of an air cycle machine according to an embodiment of the present invention being sleeved around the periphery of a transmission shaft;

[0020] Figure 4 for Figure 3 A magnified schematic diagram of point B in FIG.

[0021] Figure 5 is a half-section schematic diagram of a transmission shaft of an air cycle machine according to an embodiment of the present invention;

[0022] Figure 6 is a perspective schematic diagram of a transmission shaft of an air cycle machine according to an embodiment of the present invention;

[0023] Figure 7 A schematic perspective view of a split annular seal of an air cycle machine according to an embodiment of the present invention;

[0024] Figure 8 A schematic diagram of a split portion of an annular seal of an air cycle machine according to an embodiment of the present invention;

[0025] Figure 9 2 is a perspective schematic diagram of a stopper of an air cycle machine according to an embodiment of the present invention.

[0026] The reference numerals indicate:

[0027] 1. Drive shaft; 2. Annular seal; 21. Annular inner layer; 22. Annular outer layer; 3. Impeller; 4. Annular protrusion; 5. Annular groove; 6. Volute; 7. Sealing ring; 8. Annular slot; 9. Stopper. DETAILED DESCRIPTION

[0028] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0030] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0031] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0032] See also Figures 1 to 9 As shown, according to an embodiment of the present invention, an air cycle machine is provided, including a transmission shaft 1, an annular seal 2 and an impeller 3. The impeller 3 is mounted at one end of the transmission shaft 1. An annular protrusion 4 is formed on the outer peripheral wall of the transmission shaft 1. The annular protrusion 4 is close to the impeller 3. An annular groove 5 is constructed on the inner peripheral wall of the annular seal 2. The annular seal 2 is sleeved on the outer periphery of the transmission shaft 1, and the annular protrusion 4 is inserted into the annular groove 5.

[0033] In this technical solution, the annular protrusion 4 designed on the outer peripheral wall of the transmission shaft 1 is inserted into the annular groove 5 constructed on the inner peripheral wall of the annular seal 2, so that a close fit is produced between the annular protrusion 4 and the annular groove 5, and a good sealing performance is achieved between the annular seal 2 and the transmission shaft 1, which produces a strong flow resistance to the airflow flowing along the outer surface of the transmission shaft 1, thereby reducing the leakage of high-pressure gas from the impeller 3, and ultimately reducing the leakage of the air cycle machine.

[0034] See also Figures 2 to 4 As shown, a plurality of annular protrusions 4 are formed on the outer circumferential wall of the transmission shaft 1, and the annular protrusions 4 are distributed at intervals along the axial direction of the transmission shaft 1. A plurality of annular grooves 5 are constructed on the inner circumferential wall of the annular seal 2, and the annular grooves 5 are distributed at intervals along the axial direction of the annular seal 2. The annular protrusions 4 are respectively inserted into the annular grooves 5.

[0035] In this embodiment, the annular protrusions 4 are respectively inserted into the annular grooves 5 to form multiple flow barriers along the axial direction of the transmission shaft 1, so that the sealing effect between the annular seal 2 and the transmission shaft 1 is better and the leakage of the air cycle machine is less.

[0036] See also Figure 3 and Figure 4 As shown, the annular protrusion 4 is partially inserted into the annular groove 5, and a gap is formed between the inner circumferential wall of the annular seal 2 and the outer circumferential wall of the transmission shaft 1. This indicates that under normal circumstances, the annular seal 2 and the transmission shaft 1 do not contact each other. This prevents friction and wear between the transmission shaft 1 and the annular seal 2 during rotation, thereby preventing the annular seal 2 from causing friction and failure.

[0037] See also Figure 3 and Figure 4 As shown, the distance between the inner circumferential wall of the annular seal 2 and the outer circumferential wall of the transmission shaft 1 is H. When the distance between the inner circumferential wall of the annular seal 2 and the outer circumferential wall of the transmission shaft 1 is too small, the annular seal 2 and the transmission shaft 1 are prone to collision and wear during the start-up and shutdown stages of the air cycle machine; when the distance between the inner circumferential wall of the annular seal 2 and the outer circumferential wall of the transmission shaft 1 is too large, the leakage amount cannot meet the requirements. After repeated demonstration, it is preferably 0.3mm≤H≤0.4mm.

[0038] As a specific embodiment, along the radial direction of the transmission shaft 1, the height of the annular protrusion 4 is A, 1.0mm≤A≤1.5mm, preferably 1.2mm; along the axial direction of the transmission shaft 1, the width of the annular protrusion 4 is B, 0.5mm≤B≤0.8mm, preferably 0.65mm; along the axial direction of the transmission shaft 1, the spacing between the two annular protrusions 4 is C, 1.2mm≤B≤1.5mm, preferably 1.35mm; along the radial direction of the annular seal 2, the depth of the annular groove 5 is D, 1.0mm≤D≤1.5mm, preferably 1.2mm; along the axial direction of the annular seal 2, the width of the annular groove 5 is E, 1.2mm≤E≤1.5mm, preferably 1.35mm; along the axial direction of the annular seal 2, the spacing between the two annular grooves 5 is F, 0.5mm≤E≤0.8mm, preferably 0.65mm.

[0039] See also Figure 7 and Figure 8 As shown, the annular seal 2 includes two parts, which are butt-jointed to form the annular seal 2, so that the annular seal 2 can be easily assembled on the periphery of the transmission shaft 1 provided with the annular protrusion 4. The contact surface between the two parts is sealed with sealant.

[0040] See also Figure 1 and Figure 2 As shown, the outer periphery of the transmission shaft 1 is provided with a volute 6 , the annular seal 2 and the impeller 3 are both located in the volute 6 , and the outer peripheral wall of the annular seal 2 is sealedly connected to the inner peripheral wall of the volute 6 .

[0041] In this technical solution, when the outer peripheral wall of the annular seal 2 is sealed with the inner peripheral wall of the volute 6, it can also prevent the high-pressure airflow from leaking along the inner peripheral wall of the volute 6, so that the overall sealing effect of the air cycle machine is better, thereby further reducing the amount of air leakage of the air cycle machine.

[0042] See also Figure 3 and Figure 4 As shown, the annular seal 2 includes an annular inner layer 21 and an annular outer layer 22. The annular groove 5 is constructed on the inner circumferential wall of the annular inner layer 21. The material of the annular inner layer 21 is a flexible material, and the material of the annular outer layer 22 is a hard material. The annular outer layer 22 is interference fit with the volute 6.

[0043] In this embodiment, the annular inner layer 21 of the annular seal 2 cooperates with the annular protrusion 4 on the transmission shaft 1. If the annular protrusion 4 collides with the annular inner layer 21 during the rotation of the transmission shaft 1, since the material of the annular inner layer 21 is a flexible material, the friction damage between the annular seal 2 and the transmission shaft 1 can be significantly reduced, and the annular seal 2 will not easily fail to seal due to collision and friction. Furthermore, the annular seal 2 also needs to be fixed. When the material of the annular outer layer 22 is a hard material, the annular seal 2 can be fixed by the interference fit between the annular outer layer 22 and the volute 6, and the interference fit between the annular outer layer 22 and the volute 6 also achieves a seal between the annular seal 2 and the volute 6. Among them, the material of the annular inner layer 21 can be rubber, graphite, etc., and the material of the annular outer layer 22 can be metal.

[0044] See also Figure 2 As shown, a sealing ring 7 is sleeved on the outer peripheral wall of the annular sealing member 2 , and the sealing ring 7 is clamped between the outer peripheral wall of the annular sealing member 2 and the inner peripheral wall of the volute 6 .

[0045] In this technical solution, the addition of the sealing ring 7 can further ensure the sealing between the annular seal 2 and the volute 6 .

[0046] See also Figure 2 and Figure 7 As shown, an annular groove 8 is formed on the outer peripheral wall of the annular seal 2 , and the sealing ring 7 is partially inserted into the annular groove 8 .

[0047] In this embodiment, the structure of the annular groove 8 makes it easier to install the sealing ring 7 on the annular seal 2, while also ensuring that the sealing ring 7 will not easily change position between the annular seal 2 and the volute 6, further ensuring the sealing effect of the sealing ring 7.

[0048] See also Figure 1 and Figure 2 As shown, a stopper 9 is provided on the outer periphery of the transmission shaft 1 . The stopper 9 is located between the annular seal 2 and the impeller 3 , and the stopper 9 forms a stop for the annular seal 2 along the axial direction of the transmission shaft 1 .

[0049] In this technical solution, the baffle 9 is stuck in the volute 6, and the baffle 9 does not contact the drive shaft 1 and the impeller 3. The baffle 9 is used to prevent the annular seal 2 from shifting toward the side where the impeller 3 is located, thereby ensuring that the working position of the annular seal 2 will not change easily.

[0050] It is easy for those skilled in the art to understand that, under the premise of no conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0051] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. An air cycle machine, characterized in that: The invention comprises a transmission shaft (1), an annular seal (2) and an impeller (3), wherein the impeller (3) is mounted on one end of the transmission shaft (1), an annular protrusion (4) is formed on the outer peripheral wall of the transmission shaft (1), the annular protrusion (4) is close to the impeller (3), an annular groove (5) is constructed on the inner peripheral wall of the annular seal (2), the annular seal (2) is sleeved on the outer periphery of the transmission shaft (1), and the annular protrusion (4) is inserted into the annular groove (5).

2. The air cycle machine according to claim 1, wherein: A plurality of annular protrusions (4) are formed on the outer peripheral wall of the transmission shaft (1), and each of the annular protrusions (4) is distributed at intervals along the axial direction of the transmission shaft (1). A plurality of annular grooves (5) are constructed on the inner peripheral wall of the annular seal (2), and each of the annular grooves (5) is distributed at intervals along the axial direction of the annular seal (2). Each of the annular protrusions (4) is respectively inserted into each of the annular grooves (5).

3. The air cycle machine according to claim 1, wherein: The annular protrusion (4) is partially inserted into the annular groove (5), and a gap is formed between the inner peripheral wall of the annular seal (2) and the outer peripheral wall of the transmission shaft (1).

4. The air cycle machine according to claim 3, wherein: The distance between the inner peripheral wall of the annular seal (2) and the outer peripheral wall of the transmission shaft (1) is H, 0.3mm≤H≤0.4mm.

5. The air cycle machine according to claim 1, wherein: The annular seal (2) comprises two separate parts, which are butt-jointed and assembled to form the annular seal (2).

6. The air cycle machine according to any one of claims 1 to 5, characterized in that: The outer sleeve of the transmission shaft (1) is provided with a volute (6), the annular seal (2) and the impeller (3) are both located in the volute (6), and the outer peripheral wall of the annular seal (2) is sealedly connected to the inner peripheral wall of the volute (6).

7. The air cycle machine according to claim 6, wherein: The annular seal (2) comprises an annular inner layer (21) and an annular outer layer (22); the annular groove (5) is constructed on the inner peripheral wall of the annular inner layer (21); the annular inner layer (21) is made of a flexible material; the annular outer layer (22) is made of a hard material; and the annular outer layer (22) is interference-fitted with the volute (6).

8. The air cycle machine according to claim 6, wherein: A sealing ring (7) is sleeved on the outer peripheral wall of the annular sealing member (2), and the sealing ring (7) is clamped between the outer peripheral wall of the annular sealing member (2) and the inner peripheral wall of the volute (6).

9. The air cycle machine according to claim 6, wherein: An annular groove (8) is formed on the outer peripheral wall of the annular sealing member (2), and the sealing ring (7) is partially inserted into the annular groove (8).

10. The air cycle machine according to claim 1, wherein The outer sleeve of the transmission shaft (1) is provided with a stopper (9), the stopper (9) is located between the annular seal (2) and the impeller (3), and the stopper (9) forms a stop for the annular seal (2) along the axial direction of the transmission shaft (1).

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