Air cycle machine

Abstract

The invention provides an air cycle machine which comprises a rotating shaft and further comprises a force measuring ring, the force measuring ring is used for detecting the axial force of the rotating shaft, the radial outer side of the rotating shaft is sleeved with the force measuring ring, the force measuring ring comprises a ring body, and the two end faces of the ring body are each provided with a plurality of bosses arranged at intervals in the circumferential direction of the ring body; strain gauges are arranged at the connecting positions of at least part of the bosses and the ring body and are projected on any radial plane of the ring body, the bosses are arranged at intervals in the circumferential direction of the ring body, and the bosses on one end face of the ring body and the bosses on the other end face of the ring body are alternated. According to the invention, the bearing wear phenomenon caused by overlarge axial force can be effectively prevented; the multiple bosses are alternately arranged on the two end faces of the ring body respectively, deformation of the proving ring can be achieved through a simple structure when axial force is applied to the proving ring, then the purpose of real-time detection of the axial force is achieved, the proving ring with the simple design is more beneficial to machining, the machining cost can be remarkably reduced, and the machining difficulty can be lowered.

Description

Technical Field

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

[0002] An air cycle machine is a device that uses air as a medium and circulates compressed air to achieve a cooling effect. Its rotor components include turbines, radial shafts, thrust shafts, compressor impellers, fans, etc. The axial direction of the rotor system is supported by a pair of axial bearings. The axial unbalanced aerodynamic force between the turbine, compressor impeller, and fan needs to be distributed to the axial bearings, so that the axial bearing support force can offset the axial aerodynamic force of the rotor system.

[0003] However, due to the performance requirements of the turbine, compressor impeller, and fan and the limitations of the rotor's spatial structure, during operation, as the speed increases, the rotor will move toward the turbine side. This is because the combined force of the aerodynamic axial force toward the turbine side during the operation of the rotor is too large, exceeding the load-bearing capacity of the axial bearing, causing bearing wear and machine damage. Therefore, real-time measurement and feedback of the rotor axial force during the operation of the air cycle machine can reduce the speed and load before the axial force exceeds the design allowable value of the axial bearing, thereby preventing the axial bearing from wearing and failing. In order to address the aforementioned deficiencies, a corresponding axial force feedback mechanism needs to be set in the air cycle machine to prevent the axial bearing from wearing and failing due to excessive axial force. Summary of the invention

[0004] Therefore, the present invention provides an air cycle machine, which can solve the technical problem that the air cycle machine in the prior art lacks real-time detection of the axial force of the rotating shaft, thereby causing the axial bearing to wear and fail when the axial force is too large.

[0005] In order to solve the above problems, the present invention provides an air cycle machine, including a rotating shaft and a force measuring ring, wherein the force measuring ring is used to detect the axial force of the rotating shaft, and the force measuring ring is sleeved on the radially outer side of the rotating shaft. The force measuring ring includes a ring body, and the two end faces of the ring body respectively have a plurality of bosses arranged at intervals along the circumference thereof, and strain gauges are arranged at the connection positions between at least some of the bosses and the ring body. When projected onto any radial plane of the ring body, the bosses are arranged at intervals along the circumference of the ring body, and the bosses on one end face of the ring body are alternately arranged with the bosses on the other end face thereof.

[0006] In some embodiments, when projected on any radial plane of the ring body, the bosses are evenly spaced apart along the circumference of the ring body.

[0007] In some embodiments, the outer circumferential wall of the ring body has at least two assembly ear plates extending radially outward, and each of the assembly ear plates has an assembly hole penetrating through both side end surfaces thereof.

[0008] In some embodiments, the air cycle machine further includes an axial air suspension bearing, which includes a thrust plate fixedly connected to the rotating shaft and a first axial bearing and a second axial bearing respectively located on both sides of the thrust plate. Two groups of force measuring rings are provided, and the two groups of force measuring rings are respectively provided corresponding to the first axial bearing and the second axial bearing and can deform when in contact with the first axial bearing or the second axial bearing to detect the axial force of the rotating shaft.

[0009] In some embodiments, the axial clearance tolerance of the axial air bearing is δ, and the deflection Y of the force measuring ring does not exceed δ / 2.

[0010] In some embodiments, the radial width of the ring body is b, the circumferential spacing between two adjacent bosses on the same end surface of the ring body is l, the axial thickness of the ring body is h, the elastic modulus of the material of the ring body is E, and the maximum axial force of the rotating shaft is p, pl 3 / (32Ebh 3 )≤δ / 2; and / or, δ=0.02mm.

[0011] In some embodiments, the axial thickness of each boss is equal, and the total axial thickness of the force measuring ring is H, where H≤6 mm.

[0012] In some embodiments, the air cycle machine further comprises a volute, the rotating shaft is located in the volute, a bearing chamber is formed in the volute, the axial air suspension bearing and the force measuring ring are located in the bearing chamber, a comb tooth seal is provided at an opening at one end of the bearing chamber, the comb tooth seal is fixedly connected to the volute to form a seal for the opening of the bearing chamber, and the comb tooth seal, the force measuring ring, the first axial bearing, the thrust plate, the second axial bearing, and the force measuring ring are arranged in sequence along the axial direction of the rotating shaft.

[0013] In some embodiments, the air cycle machine further includes a plurality of guide pins, and the first axial bearing and the second axial bearing are respectively provided with assembly holes at positions corresponding to the respective assembly holes, and the first axial bearing and the second axial bearing are slidably connected to the respective guide pins via the respective assembly holes, and the force measuring ring is slidably connected to the respective guide pins via the assembly holes thereof.

[0014] In some embodiments, the comb tooth seal has a first blind hole on the end surface of one side facing the axial air suspension bearing, which is arranged corresponding to the position of each guide pin; the bearing chamber has a second blind hole on the inner wall of the chamber opposite to the comb tooth seal, which is arranged corresponding to the position of each guide pin; and both ends of each guide pin are respectively inserted between the first blind hole and the second blind hole.

[0015] The air cycle machine provided by the present invention has the following beneficial effects:

[0016] The ring body of the force measuring ring is an annular structure, which can be mounted on the radial outer side of the rotating shaft, so that the axial force can be detected in real time in the circumferential direction of the rotating shaft, and the force measuring ring is easy to match and set with the rotating shaft in the air cycle machine. Since the axial force of the rotating shaft can be detected in real time, the bearing wear caused by excessive axial force can be effectively prevented. The ring body is provided with a plurality of alternating bosses on its two end faces, and the deformation of the force measuring ring when the axial force is applied can be realized by a simple structure, so as to realize the purpose of real-time detection of the axial force. The force measuring ring with a simple design is more conducive to processing, which can significantly reduce the processing cost and difficulty.

[0017] Limiting the deflection Y of the force measuring ring to no more than half of the axial clearance tolerance of the axial air suspension bearing can prevent the force measuring ring from being too deflected, which would cause excessive axial displacement of the axial bearing on the corresponding side, while realizing axial force detection of the force measuring ring. This would cause wear of the bearing and be detrimental to the protection of the bearing.

[0018] By pl 3 / (32Ebh 3 )≤δ / 2. When the axial clearance tolerance of the corresponding axial air suspension bearing is clarified, the axial thickness h and radial width b of the ring body of the force measuring ring can be determined by the above formula, and the inner and outer diameter dimensions of the ring body can be determined by combining the center circumferential spacing l of two adjacent bosses, thereby simplifying the design process of the force measuring ring.

[0019] The positional relationship between the comb teeth seal and the inner wall of the bearing chamber is used to form the clamping and positioning of the aforementioned guide pin, simplifying the assembly process. With such a structure, the two ends of the guide pin can be transitionally fitted or even clearance-fitted with the first blind hole and the second blind hole, making assembly very convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. The drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0021] Figure 1 1 is a schematic diagram of the external structure of an air cycle machine according to an embodiment of the present invention (partial cross-section);

[0022] Figure 2 yes Figure 1 A partial enlarged view of the middle A;

[0023] Figure 3 yes Figure 2 Schematic diagram of the three-dimensional structure of the force measuring ring;

[0024] Figure 4 yes Figure 3 A front view of the force measuring ring in FIG.

[0025] Figure 5 yes Figure 4 Side view of the force measuring ring in .

[0026] The accompanying drawings are marked as follows:

[0027] 1. Force measuring ring; 11. Ring body; 12. Boss; 13. Strain gauge; 14. Assembly ear plate; 141. Assembly hole; 2. Rotating shaft; 31. Thrust plate; 32. First axial bearing; 33. Second axial bearing; 4. Volute; 5. Comb seal; 6. Radial air bearing. DETAILED DESCRIPTION

[0028] The following will be combined with the 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 described embodiments 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 by no means 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 creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the 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 devices or elements 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 contours 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 here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. 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 figure. For example, if the device in the accompanying 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° 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. If not 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 Figure 1 and Figure 5 As shown, according to an embodiment of the present invention, an air cycle machine is provided, comprising a rotating shaft 2, and a force measuring ring 1, wherein the force measuring ring 1 is used to detect the axial force of the rotating shaft 2, and the force measuring ring 1 is sleeved on the radial outer side of the rotating shaft 2. For details, see Figures 3 to 5As shown, the force measuring ring 1 includes a ring body 11, and the two end faces of the ring body 11 respectively have a plurality of bosses 12 arranged at intervals along the circumference thereof. When projected on any radial plane of the ring body 11, the bosses 12 are arranged at intervals along the circumference of the ring body 11. When projected on any radial plane of the ring body 11, the bosses 12 on one end face of the ring body 11 are alternately formed with the bosses 12 on the other end face, that is, the bosses 12 on one end face of the ring body 11 are alternately formed with the bosses 12 on the other end face, so that a deformation space can be formed on the opposite side of any boss 12 to which an axial force is applied, and at least part of the bosses 12 are connected to the ring body 11. A strain gauge 13 is arranged at the position, that is, the strain gauge 13 is arranged at the root position of each boss 12, so as to be able to more sensitively detect the slight deformation of the force measuring ring 1 when it is subjected to the axial force of the time shaft 2. It can be understood that the aforementioned strain gauge 13 has multiple pieces, and the strain signals generated by the multiple strain gauges 13 when the force measuring ring 1 is deformed are transmitted through the full-bridge circuit to the corresponding press (the press in the prior art can be used) for analysis and processing. By calibrating the corresponding curve between the pressure size and the signal strength on the press, the size and direction of the axial force during the operation of the shaft 2 can be accurately obtained, thereby sensing and detecting the axial force in real time, and preventing the axial force from being too large and causing wear of the axial air suspension bearing used in conjunction with the shaft 2.

[0033] In this technical solution, the ring body 11 of the force measuring ring 1 is an annular structure, which can be mounted on the radial outer side of the rotating shaft 2, so that the axial force can be detected in real time in the circumferential direction of the rotating shaft 2, and the force measuring ring 1 is easy to match and correspond with the rotating shaft 2 in the air cycle machine. Since the axial force of the rotating shaft 2 can be detected in real time, the bearing wear caused by excessive axial force can be effectively prevented. The ring body 11 is provided with a plurality of alternating bosses 12 on its two end faces, and the deformation of the force measuring ring 1 when the axial force is applied can be realized by a simple structure to achieve the purpose of real-time detection of the axial force. The force measuring ring 1 with a simple design is more conducive to processing, and can significantly reduce processing costs and reduce processing difficulty.

[0034] It is worth emphasizing that the force measuring ring 1 in the present application is particularly suitable when the axial installation space of the air cycle machine is small. Since the overall thickness of the force measuring ring in the present application only includes the thickness of the ring body 11 and the height of the bosses 12 on its two end faces, there is no need to design other structures for the ring body 11, such as providing corresponding deformation clearance grooves and other structures on the ring body 11. The thickness of the ring body 11 can be designed to be as small as possible (only considering its structural strength), and the bosses on the two end faces are processed on the outside, so the processing difficulty is greatly reduced.

[0035] In one embodiment, a strain gauge 13 is provided at the positions where both sides of each boss 12 are connected to the ring body 11. Each boss 12 is specifically a fan ring with a radial width equal to the width of the ring body 11, and the outer diameter and inner diameter of the fan ring are respectively equal to the outer diameter and inner diameter of the ring body 11.

[0036] In some embodiments, when projected on any radial plane of the ring body 11, the bosses 12 are evenly spaced along the circumference of the ring body 11, so that multi-point detection of the axial force in the circumferential direction can be achieved. In a preferred embodiment, a strain gauge 13 is provided at the position where each boss 12 is connected to the ring body 11, so that the circumferential multi-point comprehensive detection of the axial force can be achieved, ensuring the accuracy of the detected axial force. Each strain gauge 13 can be of the same specification and model.

[0037] The aforementioned boss 12 and the ring body 11 can be formed by machining, that is, the two are objectively an integrated structure to ensure reliable and stable deformation. The aforementioned strain gauges 13 can be connected to corresponding positions by gluing.

[0038] See Figure 3 As shown, in some embodiments, the outer circumferential wall of the ring body 11 has at least two assembly ear plates 14 extending radially outward, and each of the assembly ear plates 14 has an assembly hole 141 passing through the end surfaces on both sides thereof, that is, the assembly hole 141 is a through hole. In a specific embodiment, a total of three assembly ear plates 14 are provided, and the three assembly ear plates 14 are evenly spaced along the circumferential direction of the ring body 11.

[0039] This technical solution can achieve a limiting connection between the force measuring ring 1 and an external assembly carrier, such as the aforementioned volute 4, through at least two assembly ear plates 14, so as to match the corresponding component sizes.

[0040] In some embodiments, the air cycle machine further includes an axial air suspension bearing (not labeled in the figure), the axial air suspension bearing including a thrust plate 31 fixedly connected to the rotating shaft 2 and a first axial bearing 32 and a second axial bearing 33 respectively located on both sides of the thrust plate 31. The thrust plate 31 can be, for example, a structure integrally formed with the rotating shaft 2, or a structure assembled with the rotating shaft 2, with the design principle that the thrust plate 31 can rotate synchronously with the rotating shaft 2. Preferably, the rotating shaft 2 and the thrust plate 31 are an integrated structure, and two groups of force measuring rings 1 are provided, and the two groups of force measuring rings 1 are respectively provided corresponding to the first axial bearing 32 and the second axial bearing 33 and can deform when in contact with the first axial bearing 32 or the second axial bearing 33 to detect the axial force of the rotating shaft 2, specifically Figure 2The orientation shown is for reference. One group of force rings 1 is on the left side of the first axial bearing 32, and the other group of force rings 1 is on the right side of the second axial bearing 33. In this way, during the high-speed rotation of the rotating shaft 2, an air film with a certain rigidity is formed between the left end face of the thrust plate 31 and the first axial bearing 32, and an air film with a certain rigidity is also formed between the right end face of the thrust plate 31 and the second axial bearing 33. When the rotating shaft 2 moves axially to the left or right under the action of the axial force, the axial force will be transmitted to the corresponding axial bearing through the corresponding air film with rigidity. At this time, since the outer end face of the axial bearing is in conflict with the corresponding force ring 1, the axial force is applied to the corresponding force ring 1, and the force ring 1 is deformed under the action of the axial force. The strain gauge 13 detects the deformation amount of the connecting area between the boss 12 and the ring body 11 and converts it into a corresponding deformation signal and transmits it to the press, thereby completing the real-time detection of the axial force of the rotating shaft 2. It should be particularly noted that, since the end face of the axial bearing away from the thrust plate 31 is placed in contact with the force measuring ring 1, all axial forces of the rotating shaft 2 will be transmitted to the force measuring ring 1, thereby ensuring the accuracy of the axial force detection by the force measuring ring 1.

[0041] In some embodiments, the axial clearance tolerance of the axial air bearing is δ, and the deflection Y of the force measuring ring 1 does not exceed δ / 2. In a specific embodiment, δ=0.02mm, and correspondingly, the deflection Y does not exceed 0.01mm. It can be understood that the aforementioned deflection Y should also be greater than 0.005mm.

[0042] In this technical solution, the deflection Y of the force measuring ring 1 is limited to no more than half of the axial clearance tolerance of the axial air suspension bearing. Under the premise of realizing the axial force detection of the force measuring ring 1, it can prevent the deflection of the force measuring ring 1 from being too large, resulting in excessive axial displacement of the axial bearing on the corresponding side, which will cause wear of the bearing and is not conducive to the protection of the bearing.

[0043] It should be noted that controlling the deflection of the force measuring ring 1 is a relatively important link. If the deflection is too small, the deformation of the force measuring ring will be very small, resulting in the inability to accurately feedback small axial force changes; conversely, if the deflection is large, the force measuring ring 1 will produce a large deformation, which will have a greater impact on the performance of the axial air suspension bearing and cause the shaft 2 to directly become unstable.

[0044] In some embodiments, specifically in conjunction with Figure 4 and Figure 5As shown, the radial width of the ring body 11 is b, the circumferential spacing between two adjacent bosses 12 on the same end surface of the ring body 11 is l, the axial thickness of the ring body 11 is h, the elastic modulus of the material of the ring body 11 is E, the maximum axial force of the rotating shaft 2 is F, the pressure on a single boss 12 is p, and taking the number of bosses 12 as 8 as an example, p=F / 8, p1 3 / (32Ebh 3 )≤δ / 2, the specific derivation process is as follows:

[0045]

[0046] In the above formulas, the unit of F and p is N, the unit of l, b, h is m, the unit of E is Pa, and the unit of Y is m.

[0047] In this technical solution, through the above-mentioned definition, after the axial clearance tolerance of the corresponding axial air suspension bearing is clarified, the axial thickness h and radial width b of the ring body 11 of the force measuring ring 1 can be determined by the above-mentioned formula, and the inner and outer diameter dimensions of the ring body 11 can be clarified in combination with the center circumferential spacing l between two adjacent bosses 12, thereby simplifying the design process of the force measuring ring 1.

[0048] There are many factors that affect the deflection of the force measuring ring 1. In a specific embodiment, the relevant dimensions are as follows: b = 6mm, the height of each boss 12 is 1mm, the material of the force measuring ring 1 is 304 stainless steel, the inner diameter d of the ring body 11 is 54mm, 64mm, 74mm, 84mm, respectively, and the outer diameter D of the ring body 11 is 66mm, 76mm, 86mm, 96mm, respectively, and the thickness of the ring body 11 is h = 2mm, 3mm, 4mm. The deflection results calculated according to the above formula are shown in Table 1 below:

[0049] Table 1

[0050] D(mm)\h(mm) 2 3 4 66 0.010381 0.003076 0.001298 76 0.016484 0.004884 0.00206 86 0.024606 0.007291 0.003076 96 0.035034 0.010381 0.004379

[0051] Using the above formula pl 3 / (32Ebh 3 ) It can be concluded that when h is 3mm and D is 86mm, the axial displacement of the force measuring ring 1 is 7.2μm (ie, deflection), which can meet the requirements of the operation of the shaft 2.

[0052] In some embodiments, the axial thickness of each of the bosses 12 is equal, and the total axial thickness of the force measuring ring 1 is H, H≤6mm. The aforementioned total axial thickness H is the sum of the axial thickness h of the ring body 11 and the axial thickness of the bosses 12 on its two end surfaces. Limiting the aforementioned H to 6mm can meet the requirement of the maximum axial total thickness of the axial space in the air cycle machine.

[0053] In some embodiments, see further Figure 1 As shown, the air cycle machine further includes a volute 4 (specifically, a volute of an expansion portion), the rotating shaft 2 is located in the volute 4, and it can be understood that the rotating shaft 2 is rotatably supported in the volute 4 through corresponding radial bearings, such as a plurality of radial air suspension bearings 6. The volute 4 exists as a gas containment and an inclusion component for its internal components, and serves as an assembly carrier for various functional components inside the volute. A bearing chamber (not marked in the figure) is formed in the volute 4, the axial air suspension bearing and the force measuring ring 1 are located in the bearing chamber, and one end of the bearing chamber is open (with a Figure 1 The orientation shown is for reference, that is, a comb-tooth seal 5 is provided at the left end opening. The comb-tooth seal 5 is fixedly connected to the volute 4 to form a comb-tooth seal for the opening of the bearing chamber to prevent the pressure gas in the volute 4 from leaking through the bearing chamber. The comb-tooth seal 5, the force ring 1, the first axial bearing 32, the thrust plate 31, the second axial bearing 33, and the force ring 1 are arranged in sequence along the axial direction of the rotating shaft 2. During the rotation of the rotating shaft 2, the first axial bearing 32 and the second axial bearing 33 will be linearly displaced in the direction away from the thrust plate 31 under the action of the air film on the corresponding side, and finally the force ring 1 on the left side is clamped between the comb-tooth seal 5 and the first axial bearing 32, and the force ring 1 on the right side is clamped between the right end inner wall surface of the bearing chamber, thereby realizing the stop of the force rings 1 on the left and right sides by the comb-tooth seal 5 and the volute 4 respectively.

[0054] In some embodiments, the air cycle machine further includes a plurality of guide pins (not shown in the figure), and the first axial bearing 32 and the second axial bearing 33 are respectively provided with assembly holes (not shown in the figure) at positions corresponding to the assembly holes 141, and the first axial bearing 32 and the second axial bearing 33 are slidably connected to the guide pins via the assembly holes they have, and the force measuring ring 1 is slidably connected to the guide pins via the assembly holes 141 they have.

[0055] In this technical solution, a plurality of guide pins are used to guide the two groups of force measuring rings 1 and the first axial bearing 32 and the second axial bearing 33 to form linear displacement, thereby preventing rotation during linear displacement and ensuring reliable and stable axial force detection.

[0056] In some embodiments, the comb-tooth seal 5 has a first blind hole (not shown in the figure) arranged corresponding to the position of each guide pin on the end face of one side facing the axial air suspension bearing, and the bearing chamber has a second blind hole (not shown in the figure) arranged corresponding to the position of each guide pin on the inner wall of the chamber opposite to the comb-tooth seal 5. The two ends of each guide pin are respectively inserted between the first blind hole and the second blind hole, so that the positional relationship between the comb-tooth seal 5 and the inner wall of the bearing chamber is used to form the clamping and positioning of the aforementioned guide pin, simplifying the assembly process. With such a structure, the two ends of the guide pin can be transitionally fitted or even clearance-fitted with the first blind hole and the second blind hole, and the assembly is very convenient.

[0057] by Figure 1 Taking the orientation shown as an example, during the specific assembly, the right end of each guide pin is inserted into the corresponding second blind hole, and then the force measuring ring 1 on the right, the second axial bearing 33, the first axial bearing 32, and the force measuring ring 1 on the left are successively mounted on each guide pin, and then the first blind holes of the comb tooth seal 5 are buckled on the left end of each guide pin, and finally the comb tooth seal 5 and the volute 4 are fixed with bolts and other connecting parts. The whole assembly process is very convenient.

[0058] It is easy for those skilled in the art to understand that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. 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 invention. These improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. An air cycle machine, comprising a rotating shaft (2), characterized in that: The invention also comprises a force measuring ring (1), wherein the force measuring ring (1) is used to detect the axial force of the rotating shaft (2), the force measuring ring (1) is sleeved on the radial outer side of the rotating shaft (2), and the force measuring ring (1) comprises a ring body (11), wherein the two end faces of the ring body (11) respectively have a plurality of bosses (12) arranged at intervals along the circumference thereof, and strain gauges (13) are arranged at the connection positions between at least some of the bosses (12) and the ring body (11), and when projected onto any radial plane of the ring body (11), the bosses (12) are arranged at intervals along the circumference of the ring body (11), and the bosses (12) on one end face of the ring body (11) are alternately arranged with the bosses (12) on the other end face thereof.

2. The air cycle machine according to claim 1, characterized in that: Projected on any radial plane of the ring body (11), the bosses (12) are evenly spaced along the circumference of the ring body (11).

3. The air cycle machine according to claim 1, characterized in that: The outer circumferential wall of the ring body (11) is provided with at least two assembly ear plates (14) extending radially outward, and each of the assembly ear plates (14) is provided with an assembly hole (141) penetrating through both side end surfaces thereof.

4. The air cycle machine according to claim 3, characterized in that: It also includes an axial air suspension bearing, the axial air suspension bearing including a thrust plate (31) fixedly connected to the rotating shaft (2) and a first axial bearing (32) and a second axial bearing (33) respectively located on both sides of the thrust plate (31); two groups of force measuring rings (1) are provided, the two groups of force measuring rings (1) are respectively provided corresponding to the first axial bearing (32) and the second axial bearing (33) and can deform when in contact with the first axial bearing (32) or the second axial bearing (33) to detect the axial force of the rotating shaft (2).

5. The air cycle machine according to claim 4, characterized in that: The axial clearance tolerance of the axial air suspension bearing is δ, and the deflection Y of the force measuring ring (1) does not exceed δ / 2.

6. The air cycle machine according to claim 5, characterized in that: The radial width of the ring body (11) is b, the circumferential spacing between two adjacent bosses (12) on the same end surface of the ring body (11) is l, the axial thickness of the ring body (11) is h, the elastic modulus of the material of the ring body (11) is E, and the maximum axial force of the rotating shaft (2) is p, pl 3 / (32Ebh 3 )≤δ / 2; and / or, δ=0.02mm.

7. The air cycle machine according to claim 6, characterized in that: The axial thickness of each boss (12) is equal, and the total axial thickness of the force measuring ring (1) is H, H≤6mm.

8. The air cycle machine according to claim 4, characterized in that: It also comprises a volute (4), the rotating shaft (2) is located in the volute (4), a bearing chamber is formed in the volute (4), the axial air suspension bearing and the force measuring ring (1) are located in the bearing chamber, a comb tooth seal (5) is provided at an opening at one end of the bearing chamber, the comb tooth seal (5) is fixedly connected to the volute (4) to form a seal for the opening of the bearing chamber, and the comb tooth seal (5), the force measuring ring (1), the first axial bearing (32), the thrust plate (31), the second axial bearing (33), and the force measuring ring (1) are arranged in sequence along the axial direction of the rotating shaft (2).

9. The air cycle machine according to claim 8, characterized in that: It also includes a plurality of guide pins. The first axial bearing (32) and the second axial bearing (33) are provided with assembly holes at positions corresponding to the assembly holes (141). The first axial bearing (32) and the second axial bearing (33) are slidably sleeved on the guide pins via the assembly holes they have. The force measuring ring (1) is slidably sleeved on the guide pins via the assembly holes (141) they have.

10. The air cycle machine according to claim 9, characterized in that The comb-tooth seal (5) has a first blind hole on its end face facing the axial air suspension bearing, which is arranged corresponding to the position of each guide pin; the bearing chamber has a second blind hole on its inner wall opposite to the comb-tooth seal (5), which is arranged corresponding to the position of each guide pin; and both ends of each guide pin are respectively inserted between the first blind hole and the second blind hole.

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