Method for improving the life of supercharged turbine in oxygen-generating system and turbine axial force testing device and method

Abstract

The present invention discloses a method for improving the service life of a supercharged turbine in a mechanical oxygen system, as well as a turbine axial force testing device and method. The turbine axial force testing device includes a shaft, bearings, bushings, bearing housings, sealing bushings, impellers, intermediate housings, volutes, and a data acquisition instrument, strain conditioner, stress ring, press, etc. required for axial force testing. During the axial force test, the force-strain relationship and temperature-strain relationship of the stress ring are tested separately. When the test result error is within a set range, the axial force value is determined by combining the strain value in the temperature-strain relationship with the force-strain relationship. The present invention determines the key factors that affect the service life of the supercharged turbine, and at the same time realizes the axial force test of the supercharged turbine in the mechanical oxygen system, providing a reliable and powerful basis for the axial force balance design of the supercharged turbine to ensure the operating life of the supercharged turbine.

Description

Technical Field

[0001] The present invention belongs to the technical field of mechanical manufacturing, and in particular relates to a method for improving the service life of a supercharged turbine in a machine-generated oxygen system, and a device and method for testing the axial force of a supercharged turbine in a machine-generated oxygen system. Background Art

[0002] A supercharger turbine consists of a compressor and a turbine, and its bearings are grease-lubricated. The supercharger turbine is used in aircraft oxygen concentrators, where it boosts low-pressure air to supply the oxygen concentrator. Therefore, the stable operation of the supercharger turbine is crucial for pilots. Furthermore, the lifespan of the supercharger turbine determines both maintenance costs and flight safety. Summary of the Invention

[0003] The present invention aims to provide a method for improving the service life of a supercharged turbine in a mechanical oxygen system, as well as a turbine axial force testing device and method. On the one hand, the method determines the key factors affecting the stability and service life of the supercharged turbine. On the other hand, the method solves the problem that the axial force of the supercharged turbine is difficult to test and has large errors. Furthermore, the method solves the problem that it is difficult to design the axial force matching of the supercharged turbine bearing, thereby providing positive and reliable axial force data for the supercharged turbine design.

[0004] The present invention discovered that the service life of a turbocharger turbine is primarily determined by the service life of its bearings, and the proper functioning of the bearings is determined by the axial forces they withstand during use and the bearing temperature. Among the turbocharger repair cases handled, most damage was caused by excessive axial forces, leading to bearing damage. Therefore, accurately measuring the axial forces exerted on the turbocharger bearings during use can help improve turbocharger reliability and thus extend their service life. This method has extremely important practical significance.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for improving the service life of a supercharged turbine in a mechanical oxygen system, wherein the supercharged turbine in the mechanical oxygen system includes a bearing at the compressor end and a bearing at the turbine end, the method comprising:

[0007] Accurately measure the axial forces acting on the compressor-end bearings and the turbine-end bearings of the turbocharger under various operating conditions, and select bearings with matching specifications based on the measured axial force data.

[0008] Furthermore, the bearing is an angular contact ball bearing.

[0009] The axial force test device for the turbocharger of the oxygen system includes a shaft, bearings, bushings, bearing housings, sealing bushings, impellers, intermediate housings, self-locking nuts, volutes, data acquisition instruments, strain conditioners, stress rings and presses required for axial force testing, including:

[0010] The two bearings and the bushing are respectively sleeved on the shaft, and the two bearings are respectively located at the left and right ends of the bushing in the axial direction, and the shaft, bearings and bushing are all installed in the bearing housing;

[0011] The bearing housing is installed in the intermediate housing;

[0012] The two stress rings are respectively installed between the axial end surface of the bearing and the axial end surface of the bushing;

[0013] The stress ring is led out from the bearing housing through the intermediate housing via a lead wire and then connected to a strain conditioner, and the strain conditioner is connected to a data acquisition instrument;

[0014] The two sealing bushings are respectively sleeved on the shaft and located outside the two bearings;

[0015] The two impellers are respectively mounted on both ends of the shaft through self-locking nuts, and the end faces of the two impellers are respectively pressed against the end face of the sealing bushing;

[0016] The two volutes are respectively mounted on the outer sides of the two impellers so that the impellers are located inside the volutes.

[0017] Furthermore, the stress ring includes a ring member and a strain gauge, wherein steps are respectively provided on two axial end faces of the ring member, and the strain gauge is mounted on the axial end face of the ring member and does not overlap with the position of the steps;

[0018] A notch is provided on the axial end surface of the bushing facing the bearing, the stress ring passes through the shaft, and the step on the axial end surface is embedded in the notch on the axial end surface of the bushing.

[0019] The stress ring can be an existing stress ring product or a self-designed one based on the size and installation position of the turbocharger bearing. Its purpose is to accurately measure the axial force of the bearing end face. During installation, it is ensured that the axial and radial positions of the stress ring are both positioned by a positioning mechanism.

[0020] Furthermore, the axial movement of the turbocharger should be within 0.1 mm, that is, the axial displacement of the shaft should be within 0.1 mm.

[0021] The two stress rings are led out from the bearing housing through the intermediate housing via leads and then connected to the strain conditioner via a full-bridge connection. Since full-bridge connection is a common connection method for stress-strain testing, it will not be described in detail here.

[0022] The method for testing the axial force of the supercharged turbine of the oxygen-generating system includes the following steps:

[0023] Step 1: After completing the assembly of the supercharger turbine, check whether the axial movement of the supercharger turbine is normal. If the axial movement is normal, remove the volutes on both sides of the supercharger turbine and install them on a press. Calibrate the force-strain relationship of the two stress rings by applying proportionally increasing forces;

[0024] Step 2: Reassemble the turbocharger (reinstall the volute removed in step 1), then place it in a high-temperature test chamber, adjust the test chamber temperature to different values, and calibrate the temperature-strain relationship of the two stress rings;

[0025] Step 3: Install the supercharger turbine on a test bench (here refers to the test bench equipment for supercharger turbine performance testing and operation), start the supercharger turbine, and at the same time, the data acquisition instrument begins to collect signals. After the supercharger turbine reaches the specified operating parameters, it runs stably for a period of time, and then stops until the supercharger turbine stops working and the data acquisition instrument stops collecting data;

[0026] Step 4: Repeat step 3 to perform multiple tests and calculate the average microstrain collected by the data acquisition instrument, that is, repeat step 3 to obtain multiple groups of microstrain values, and calculate the average value of the multiple groups of microstrain values ​​as the average microstrain;

[0027] Step 5: Remove the turbine casings on both sides of the supercharger turbine and install the supercharger turbine on a press. Apply the force of step 1 (i.e., apply a proportionally increased force as in step 1) to calibrate the force-strain relationship of the two stress rings and compare the two data. The test is valid if the error is within 5%;

[0028] Step 6: Compare the average microstrain value measured in step 4 with the force-strain curve of the stress ring measured in step 1 to obtain the axial force value of the supercharger turbine at the operating point.

[0029] The press described in the present invention includes a mounting plane and a pressure plane. When in use, the supercharger turbine is placed on the mounting plane, and the pressure plane is driven by a power source to press toward one end of the shaft, thereby applying force to the supercharger turbine.

[0030] Compared with the prior art, the device and method for testing the axial force of a supercharged turbine in an oxygen generating system of the present invention have the following advantages and effects:

[0031] (1) The oxygen-generating system turbocharger turbine axial force test device of the present invention can test the real-time axial force borne by the bearings on both sides of the turbocharger turbine and obtain the real-time axial force value, thereby providing positive and reliable axial force data for the turbocharger turbine design.

[0032] (2) The oxygen-generating system turbocharger turbine axial force testing device of the present invention can collect and record the real-time axial force data borne by the turbocharger turbine bearing under various working conditions.

[0033] (3) The oxygen-generating system turbocharger turbine axial force test device of the present invention rationally selects the main structural components in the turbocharger turbine that affect the accuracy of the axial force test results, and excludes other structures that are not critical factors, so that the test device is simplified while accurately reflecting the axial force.

[0034] (4) Based on the accurate axial force value obtained from the test, the appropriate bearing specifications can be determined and selected, thereby improving the stability and service life of the turbocharger. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the axial force testing device and data collection system of the oxygen-generating system supercharger turbine of the present invention;

[0036] Figure 2 Schematic diagram of the structure of the axial force test device for the supercharged turbine of the oxygen-generating system of the present invention;

[0037] Figure 3 This is a cross-sectional view of the installation of a stress ring in the axial force test device for a supercharged turbine in a mechanical oxygen system of the present invention;

[0038] Figure 4 It is a schematic diagram of the stress ring in the axial force test device of the supercharged turbine of the oxygen-generating system of the present invention;

[0039] In the figure, 1-shaft, 2-bearing, 3-bushing, 4-bearing housing, 5-sealing bushing, 6-impeller, 7-intermediate housing, 8-self-locking nut, 9-volute, 10-stress ring. DETAILED DESCRIPTION

[0040] The present invention is further described below with reference to the accompanying drawings and specific embodiments. However, it should not be understood that the scope of the subject matter described in the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various modifications, substitutions and changes made according to common technical knowledge and customary means in the field are included in the scope of the present invention.

[0041] like Figure 1 As shown, the basic principle of the oxygen system turbocharger axial force testing device of the present invention is demonstrated, that is, measuring the axial force between the compressor end and the turbine end of the turbocharger, and using a stress ring 10, a data acquisition instrument, a strain conditioner and a press to realize the test.

[0042] In this embodiment, the axial force test device for the supercharged turbine of the oxygen system includes a shaft 1, a bearing 2, a bushing 3, a bearing housing 4, a sealing bushing 5, an impeller 6, an intermediate housing 7, a self-locking nut 8, a volute 9, and a data acquisition instrument, a strain conditioner, a stress ring 10, and a press required for the axial force test. Figure 2As shown, the shaft 1, two bearings 2, and the bushing 3 are installed in the bearing housing 4; two stress rings 10 are respectively installed between the axial end faces of the bearings 2 on both sides of the supercharged turbine and the axial end faces of the bushing 3; the bearing housing 4 is installed on the intermediate housing 7; the sealing bushing 5 is installed on both sides of the shaft 1 and then the impeller 6 is installed on the shaft 1 (the sealing bushing 5 and the impeller 6 are both connected in series on the shaft 1), the impeller 6 is pressed against the end face of the sealing bushing 5, and then the impeller 6 is fixed with a self-locking nut 8, and then the volutes 9 on both sides are installed; the lead of the stress ring 10 is led out through the bearing housing 4 and the intermediate housing 6 and then connected to the strain conditioner, and the strain conditioner is then connected to the data acquisition instrument.

[0043] like Figure 3 There are two stress rings 10, one on each side of the turbocharger, installed between the bearing 2 and the bushing 3. This allows for more accurate measurement of the axial force acting on the bearing 2. The stress rings 10 are pressed against the bearing 2 to secure their axial position, and the notches on the bushing 3 secure their radial position.

[0044] like Figure 4 The stress ring 10 is a ring-shaped part. Four steps are provided on each of the two axial end faces of the ring. A strain gauge is installed on the axial end face of the ring and at a position that does not overlap with the steps. Figure 4 The four steps on one end face are rotated 45° relative to the four steps on the other end face, with the center of the ring as the rotation center, so that the steps on both sides are staggered by 45°. The leads of the two stress rings 10 pass through the bearing housing 4, then through the intermediate housing 6 and are connected to the strain conditioner via a "full-bridge" connection method.

[0045] The method for performing axial force testing using the above-mentioned oxygen-generating system supercharger turbine axial force testing device comprises the following steps:

[0046] Step 1, follow Figure 2 After completing the assembly of the supercharger turbine, check the axial movement of the supercharger turbine. If the axial movement is normal, remove the volutes 9 on both sides of the supercharger turbine and install the supercharger turbine on the press. Apply proportionally increasing forces to calibrate the "force-strain" relationship of the stress rings 10 on both sides.

[0047] Step 2: Reassemble the turbocharger (reinstall the turbine housing removed in step 1), then place it in a high-temperature test chamber. Adjust the test chamber temperature to 50 / 100 / 150 / 200°C, and calibrate the "temperature-strain" relationship of the stress rings 10 on both sides.

[0048] Step 3: Install the supercharger turbine on the test bench, start the supercharger turbine, and simultaneously start the data acquisition instrument to collect signals. After the supercharger turbine reaches the specified operating parameters, run it stably for 2 minutes, then shut it down until the supercharger turbine stops working and the data acquisition instrument stops collecting data.

[0049] Step 4: Repeat step 3 to perform multiple tests and calculate the average microstrain collected by the data acquisition instrument;

[0050] Step 5: Remove the volutes 9 on both sides of the supercharger turbine, install the supercharger turbine on a press, apply the force of step 1 (according to the force application method of step 1) to calibrate the "force-strain" relationship of the stress rings 10 on both sides, and compare the two data. The test is valid if the error is within 5%;

[0051] Step 6: Compare the microstrain value measured in step 4 with the “force-strain” relationship curve of the stress ring 10 measured in step 1 to obtain the axial force value of the turbocharger at the operating point.

[0052] The above embodiments are not intended to limit the protection scope of the present invention. Any variations, modifications or equivalent substitutions made on the basis of the technical solution of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for testing the axial force of a turbocharger turbine in an oxygen generating system, characterized by: The adopted axial force testing device for a supercharged turbine of a mechanical oxygen system comprises a shaft (1), a bearing (2), a bushing (3), a bearing housing (4), a sealing bushing (5), an impeller (6), an intermediate housing (7), a self-locking nut (8), a volute (9), a data acquisition instrument required for the axial force test, a strain conditioner, a stress ring (10) and a press, wherein: The two bearings (2) and the bushing (3) are respectively sleeved on the shaft (1), and the two bearings (2) are respectively located at the left and right ends of the bushing (3) in the axial direction, and the shaft (1), the bearings (2) and the bushing (3) are all installed in the bearing housing (4); The bearing housing (4) is installed in the intermediate housing (7); The two stress rings (10) are respectively installed between the axial end surface of the bearing (2) and the axial end surface of the bushing (3); The stress ring (10) is led out from the bearing housing (4) through the intermediate housing (7) via a lead wire and then connected to a strain conditioner, and the strain conditioner is connected to a data acquisition instrument; The two sealing bushings (5) are respectively sleeved on the shaft (1) and located outside the two bearings (2); The two impellers (6) are respectively mounted on both ends of the shaft (1) through self-locking nuts (8), and the end faces of the two impellers (6) are respectively pressed against the end faces of the sealing bushings (5); The two volutes (9) are respectively installed on the outsides of the two impellers (6) so that the impellers (6) are located inside the volutes (9); the method for testing the axial force of the supercharged turbine of the oxygen generating system includes: Step 1: After completing the assembly of the supercharger turbine, check whether the axial movement of the supercharger turbine is normal. When the axial movement is normal, remove the volutes (9) on both sides of the supercharger turbine and install them on a press. Calibrate the force-strain relationship of the two stress rings (10) by applying proportionally increasing forces. Step 2: Reassemble the supercharged turbine and then place it in a high-temperature test chamber, adjust the temperature of the test chamber to different temperature values, and calibrate the temperature-strain relationship of the two stress rings (10); Step 3: Install the supercharger turbine on the test bench, start the supercharger turbine, and simultaneously, the data acquisition instrument begins to collect signals. After the supercharger turbine reaches the specified operating parameters, it is allowed to run stably for a period of time, and then shut down until the supercharger turbine stops working and the data acquisition instrument stops collecting data. Step 4: Repeat step 3 to perform multiple tests and calculate the average microstrain collected by the data acquisition instrument; Step 5: Remove the volutes (9) on both sides of the supercharger turbine, install the supercharger turbine on a press, calibrate the force-strain relationship of the two stress rings (10) by applying the force of step 1, and compare the two data. The test is valid if the error is within 5%; Step six, comparing the average microstrain value measured in step four with the force-strain relationship curve of the stress ring (10) measured in step one, and obtaining the axial force value of the supercharged turbine at the operating point.

2. The method for testing the axial force of a supercharged turbine in a mechanical oxygen system according to claim 1, characterized in that: The stress ring (10) comprises an annular member and a strain gauge, wherein steps are respectively provided on two axial end faces of the annular member, and the strain gauge is mounted on the axial end face of the annular member and does not overlap with the position of the steps; The axial end face of the bushing (3) facing the bearing (2) is provided with a notch, the stress ring (10) passes through the shaft (1) and the step on the axial end face is embedded in the notch of the axial end face of the bushing (3).

3. The method for testing the axial force of a supercharged turbine in a mechanical oxygen system according to claim 1, characterized in that: The axial movement of the turbocharger should be within 0.1mm.

4. The method for testing the axial force of a supercharged turbine in a mechanical oxygen system according to claim 1, characterized in that: The two stress rings (10) are led out from the bearing housing (4) through the intermediate housing (7) via leads, and are then connected to the strain conditioner via a full-bridge connection.

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