Rotary joint test system and test method thereof

Abstract

The invention discloses a rotary joint testing system and a testing method thereof, a rotary joint comprises an inner shaft and a shell which are assembled in a clearance sealing manner, an oil inlet A, an oil inlet B and an oil return port L are formed in the shell, the testing system comprises a main oil way communicated to an oil tank through a pump, and the main oil way is connected to an oil way I and an oil way II through a three-way valve in a split-flow manner; the oil way I is connected to the oil inlet A and is laterally connected with the oil return branch A; the oil way II is connected to an oil inlet B and is laterally connected with an oil return branch B; the oil return branch C is connected to the oil return port L, and the oil return port L is in an oil return state; the oil inlet A and the oil inlet B are both in an oil inlet state, or one is in the oil inlet state, and the other is in an oil return state; through oil inlet and oil return setting at the oil inlets A and B, the leakage rate under different test settings is obtained, the sealing performance of the gap between the inner shaft and the shell is tested, the gap sealing performance of the rotary joint is guaranteed greatly, the operation is convenient, and the test is reliable.

Description

Technical Field

[0001] This invention relates to the field of testing equipment technology, and in particular to a rotary joint testing system and its testing method. Background Technology

[0002] A rotary joint is a precision adapter that transfers fluid (such as liquid) from a stationary pipe to a rotating or reciprocating device. It has a wide range of applications and is suitable for industrial environments where media need to be transferred to / from rotating rollers, drums, turntables, or spindles.

[0003] To facilitate transition applications, rotary joints typically consist of a rotating part and a fixed part, such as a rotating inner shaft and a fixed outer shell. The inner shaft is rotatably fitted relative to the outer shell, and fluid entering from the outer shell exits through the inner shaft. To ensure smooth and reliable relative rotation, a gap seal is usually used between the inner shaft and the outer shell. Different gap values ​​are set according to different usage requirements and scenarios.

[0004] In existing technologies, different clearance settings correspond to different leakage rates for the gap seal, while the leakage rate is a relatively constant value under the same clearance setting. In actual operation, due to the existence of form and position tolerances, the rotary joint is affected by machining and assembly, resulting in unstable quality, such as uneven rotation and coaxiality deviation. This causes deviations in the leakage rate of the gap seal, sometimes far exceeding the preset constant value, severely affecting the normal use of the rotary joint. Therefore, quality inspection of the rotary joint is necessary to determine if there are any abnormalities in its gap seal performance. Currently, there is no standard testing method for the gap seal performance of rotary joints. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a reasonably structured rotary joint testing system and its testing method, thereby enabling the testing of the sealing performance of the gap between the inner shaft and the outer shell. This greatly helps to ensure the gap sealing performance of the rotary joint, guarantee the quality of the rotary joint, and is convenient to operate and reliable in testing.

[0006] The technical solution adopted in this invention is as follows: A rotary joint testing system is disclosed. The rotary joint includes an inner shaft and a housing with a clearance seal. An oil inlet A, an oil inlet B, and an oil return port L are provided through the housing. The testing system includes a test oil circuit, which includes a main oil circuit connected to an oil tank via a pump. The main oil circuit is split into two oil circuits via a three-way valve: oil circuit one is connected to oil inlet A, and a return branch A is connected to it on one side. Oil circuit two is connected to oil inlet B, and a return branch B is connected to it on one side. The system also includes a return branch C connected to the return port L, which is in a return state. Both oil inlets A and B are in an oil inlet state, or one is in an oil inlet state and the other is in a return state.

[0007] As a further improvement to the above technical solution: The oil inlet or return flow rate of oil inlet A is measured by flow meter one connected in series in oil circuit one, and the oil inlet or return flow rate of oil inlet B is measured by flow meter two connected in series in oil circuit two. When in the oil inlet state, the corresponding flow meter measures the oil inlet flow rate, and when in the oil return state, the corresponding flow meter measures the oil return flow rate. The oil return flow rate is the leakage amount occurring at the corresponding oil inlet.

[0008] The rotary joint is supported and fixed on an external platform by the outer shell. The end of the inner shaft is connected to the rotation drive power. The rotation drive power drives the inner shaft to rotate relative to the outer shell. Combined with the oil inlet A and oil inlet B oil inlet settings, the sealing performance of the gap between the outer shell and the inner shaft is dynamically tested.

[0009] The first oil circuit is connected in series with the first valve and the first flow meter and connected to the oil inlet A. The oil circuit between the first valve and the first flow meter is connected to the return oil branch A. The return oil branch A is connected in series with the second valve and connected to the return oil first. When the first valve is in the connected state and the second valve is in the disconnected state, the oil inlet A is in the oil inlet state. Otherwise, the oil inlet A is in the oil return state.

[0010] The oil circuit 2 is connected in series with valve 3 and flow meter 2 and connected to oil inlet B. The oil circuit 2 located between valve 3 and flow meter 2 is connected to oil return branch B. The oil return branch B is connected in series with valve 4 and connected to oil return 2. When valve 3 is in the connected state and valve 4 is in the disconnected state, oil inlet B is in the oil inlet state, and vice versa.

[0011] Pressure sensor 1 is installed at oil inlet A to monitor the pressure at oil inlet A, and pressure sensor 2 is installed at oil inlet B to monitor the pressure at oil inlet B.

[0012] A filter assembly and a check valve are connected to the main oil line located between the pump and the three-way valve; a branch line connecting to the oil tank is also connected to the main oil line located between the pump and the filter assembly, and a main circuit valve is connected to the branch line.

[0013] It also includes an oil cooler, and a cooling circuit is connected between the oil tank and the oil cooler to cool the oil in the tank; the oil tank is also equipped with a thermometer and a level gauge to monitor the oil temperature and level in the tank in real time.

[0014] A test method for the rotary joint test system, wherein the gap seal between the inner shaft and the outer shell of the rotary joint is disassembled into three sections along the axial direction according to the positions of oil inlet A and oil inlet B, namely the first section located between oil inlet A and oil return L, the second section located between oil inlet A and oil inlet B, and the third section located between oil inlet B and oil return L. Test 1: When oil is only supplied through inlet A, oil will be returned through inlet B and outlet L to obtain the oil supply volume Q at inlet A. A进 Oil return volume Q at oil inlet B B回 Oil return volume Q B回 Corresponding to the leakage amount Q2 in the second segment, the oil return amount Q at the return port L is... L回 Oil intake quantity Q A进 With return oil volume Q B回 The difference, return oil volume Q L回 This corresponds to the leakage amount Q1 in the first segment; Test 2: When oil is only supplied through inlet B, oil will be returned from inlet A and outlet L to obtain the oil supply quantity Q at inlet B. B进 Oil return volume Q at oil inlet A A回 Oil return volume Q A回 Corresponding to the leakage amount Q2 in the second segment, the oil return amount Q at the return port L is... L回 Oil intake quantity Q B进 With return oil volume Q A回 The difference, return oil volume Q L回 This corresponds to the leakage amount Q3 in the third segment; Test 3: When oil is flowing into both inlet A and inlet B, oil will return from outlet L; obtain the oil inflow Q at inlet A. A进 Oil inlet B, oil flow rate Q B进 Then the oil return volume Q at the return port L L回 Oil intake quantity Q A进 With oil intake Q B进 The sum of the oil return volume Q L回 The leakage amount Q corresponds to the first and third segments. 1+3 ; The leakage amounts in Test 1 (Q1), Test 2 (Q3), and Test 3 (Q) will be tested. 1+3 Compare each value with a preset value. If all values ​​are less than the preset value, and the sum of the leakage amounts Q1 and Q3 is less than the leakage amount Q... 1+3 If the results are close to the original, the test is passed; otherwise, the test is failed.

[0015] As a further improvement to the above technical solution: The testing method includes static testing and dynamic testing. In static testing, both the inner shaft and the outer shell are stationary. In dynamic testing, the inner shaft rotates relative to the outer shell. In the dynamic test, different speeds are set and tests are performed according to Test 1, Test 2, and Test 3. If the leakage amount in the first, second, and third sections is basically constant under different speeds and the change is within an acceptable threshold, then the dynamic test is qualified.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention, through the oil inlet and return settings at inlets A and B, allows for leakage testing under different test settings, enabling testing of the gap sealing performance between the inner shaft and the outer shell. This greatly helps ensure the gap sealing performance of the rotary joint, guaranteeing the quality of the rotary joint. It is easy to operate and reliable in testing. The present invention also includes the following advantages: The flow meter in oil circuit 1 measures the oil inlet or return at inlet A, and the flow meter in oil circuit 2 measures the oil inlet or return at inlet B, satisfying different oil inlet or return setting test requirements. The structure is simplified and the connection layout is ingenious and reasonable. By cleverly utilizing the two oil inlets and one oil return port on the rotary joint, the gap sealing section between the inner shaft and the outer shell of the rotary joint is divided into three sections. Through oil circuit connection and test settings, a comprehensive leakage test is conducted on the gap sealing section, effectively ensuring the sealing performance of the rotary joint and guaranteeing quality. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the testing system of the present invention.

[0018] Figure 2 This is a schematic diagram of the rotary joint of the present invention.

[0019] Figure 3 This is a schematic diagram illustrating the testing principle of the rotary joint of the present invention.

[0020] The components include: 1. Main oil circuit; 2. Three-way valve; 3. Check valve; 4. Filter assembly; 5. Pump; 6. Thermometer; 7. Oil tank; 8. Level gauge; 9. Main circuit valve. 10. Rotary drive power; 20. Rotary joint; 30. Test oil circuit; 40. Cooling circuit; 50. V-type support; 21. Oil inlet A; 22. Oil inlet B; 23. Oil return port L; 24. Inner shaft; 25. Housing; 31. Oil circuit one; 32. Oil circuit two; 33. Main return oil; 311. Valve 1; 312. Return oil 1; 313. Valve 2; 314. Flow meter 1; 315. Pressure sensor 1; 321. Valve 3; 322. Valve 4; 323. Return oil 2; 324. Flow meter 2; 325. Pressure sensor 2. Detailed Implementation

[0021] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0022] like Figure 1 , Figure 2 and Figure 3As shown in this embodiment, a rotary joint testing system includes a rotary joint 20 comprising an inner shaft 24 with a gap seal and a housing 25. The housing 25 has an oil inlet A21, an oil inlet B22, and an oil return port L23. The testing system includes a test oil circuit 30, which includes a main oil circuit 1 connected to an oil tank 7 via a pump 5. The main oil circuit 1 is branched to oil circuit 31 and oil circuit 32 via a three-way valve 2. Oil circuit 31 is connected to the oil inlet A21 and has a lateral oil return branch A. Oil circuit 32 is connected to the oil inlet B22 and has a lateral oil return branch B. It also includes an oil return branch C connected to the oil return port L23, which is in a return state. Both the oil inlet A21 and the oil inlet B22 are in an inlet state, or one is in an inlet state and the other is in a return state.

[0023] In this embodiment, by setting the oil inlet and return at oil inlet A21 and oil inlet B22, leakage can be tested under different test settings, thereby achieving the test of the sealing performance of the gap between the inner shaft 24 and the outer shell 25.

[0024] In this embodiment, oil is supplied from the main oil line 1 to the oil inlet A21 via oil line 31, or oil is returned from the oil inlet A21 via the return branch A; similarly, oil is supplied from the main oil line 1 to the oil inlet B22 via oil line 32, or oil is returned from the oil inlet B22 via the return branch B.

[0025] In this embodiment, oil inlet A21 and oil inlet B22 can be set to oil supply state or oil return state according to different test requirements; oil return port L23 is always in oil return state through oil return branch C. In one embodiment, oil return branch C can be connected to main oil return 33.

[0026] In actual operation, one of the oil inlet A21 and oil inlet B22 can be set to the oil inlet state to obtain the oil inlet quantity Q. 进 Another setting is to obtain the return oil volume Q under the return oil state. 回 The leakage Q at the return port L23 L回 This is the oil inlet quantity Q. 进 With return oil volume Q 回 The difference; of course, both oil inlet A21 and oil inlet B22 can be set to oil inlet state to obtain the oil inlet volume respectively, then the leakage at oil return port L23 is the sum of the oil inlet volumes at the two oil inlets.

[0027] The oil inlet or return flow rate of oil inlet A21 is measured by flow meter 314 connected in series in oil circuit 31, and the oil inlet or return flow rate of oil inlet B22 is measured by flow meter 324 connected in series in oil circuit 32. When in the oil inlet state, the corresponding flow meter measures the oil inlet flow rate, and when in the oil return state, the corresponding flow meter measures the oil return flow rate. The oil return flow rate is the leakage amount occurring at the corresponding oil inlet.

[0028] In this embodiment, flow meter 314 in oil circuit 31 measures the oil inlet or return at inlet A21, and flow meter 324 in oil circuit 32 measures the oil inlet or return at inlet B22, thus meeting different oil inlet or return setting test requirements. The structure is simplified and the connection layout is ingenious and reasonable.

[0029] The rotary joint 20 is supported and fixed on the external platform by the housing 25. The end of the inner shaft 24 is connected to the rotation drive power 10. The rotation drive power 10 drives the inner shaft 24 to rotate relative to the housing 25. Combined with the oil inlet A21 and oil inlet B22 oil inlet settings, the sealing performance of the gap between the housing 25 and the inner shaft 24 is dynamically tested.

[0030] In this embodiment, the inner shaft 24 is driven to rotate by the rotation drive power 10, thereby enabling the sealing performance test of the rotary joint 20 gap seal in the rotating state, which is more in line with the actual use scenario and matches and meets the actual use of the rotary joint 20.

[0031] In this embodiment, the rotation drive power 10 can be a motor assembly, which drives the inner shaft 24 to rotate according to the test requirements.

[0032] In actual operation, the rotary joint 20 can be placed and fixed on an external platform via the housing 25, for example, by being supported and fixed by the V-shaped support 50.

[0033] A valve 311 and a flow meter 314 are connected in series on oil circuit 31 and connected to the oil inlet A21. Oil circuit 31, located between valve 311 and flow meter 314, is laterally connected to return oil branch A. A valve 313 is connected in series on return oil branch A and connected to return oil 312. When valve 311 is in the connected state and valve 313 is in the disconnected state, oil inlet A21 is in the oil inlet state; otherwise, oil inlet A21 is in the oil return state.

[0034] In this embodiment, the opening and closing of valve 311 adjusts whether oil enters through the oil inlet A21 in oil circuit 31, and the opening and closing of valve 313 adjusts whether oil returns through the return branch A of the oil inlet A21. The opening and closing states of valve 311 and valve 313 are opposite to satisfy the oil inlet A21's oil entry or return. For example, when valve 311 is closed and valve 313 is open, oil inlet A21 is in the oil entry state; when valve 311 is open and valve 313 is closed, oil inlet A21 is in the oil return state.

[0035] Oil circuit 2 32 is connected in series with valve 321 and flow meter 2 324 and connected to oil inlet B22. Oil circuit 2 32 located between valve 321 and flow meter 2 324 is connected to return oil branch B. Oil return branch B is connected in series with valve 4 322 and connected to return oil 2 323. When valve 3 321 is in the connected state and valve 4 322 is in the disconnected state, oil inlet B22 is in the oil inlet state, and vice versa.

[0036] In this embodiment, the opening and closing of valve 321 adjusts whether oil enters through the oil inlet B22 in oil circuit 2 32, and the opening and closing of valve 422 adjusts whether oil returns through the return branch B to the oil inlet B22. The opening and closing states of valve 321 and valve 422 are opposite to satisfy the oil inlet B22's oil entry or return. For example, when valve 321 is closed and valve 422 is open, oil inlet B22 is in the oil entry state; when valve 321 is open and valve 422 is closed, oil inlet B22 is in the oil return state.

[0037] Pressure sensor 315 is installed at oil inlet A21 to monitor the pressure at oil inlet A21, and pressure sensor 325 is installed at oil inlet B22 to monitor the pressure at oil inlet B22.

[0038] In this embodiment, pressure at oil inlet A21 and oil inlet B22 is tested using pressure sensor 315 and pressure sensor 325, ensuring that the test is conducted under the set pressure. At the same time, the sealing performance of the rotary joint 20 can be judged by monitoring the pressure and combining the leakage test value with the pressure change.

[0039] In practice, the pressure during testing usually does not change, but excessive leakage can cause pressure changes.

[0040] A filter assembly 4 and a check valve 3 are connected to the main oil circuit 1 located between pump 5 and three-way valve 2, which effectively ensures the test oil supply from oil tank 7 through pump 5 and main oil circuit 1 to rotary joint 20; a branch line connecting to oil tank 7 is connected to the side of the main oil circuit 1 located between pump 5 and filter assembly 4, and a main circuit valve 9 is connected to the branch line.

[0041] It also includes an oil cooler, and a cooling circuit 40 is connected between the oil tank 7 and the oil cooler to cool the oil in the oil tank 7; the oil tank 7 is also equipped with a thermometer 6 and a level gauge 8 to monitor the oil temperature and level in the oil tank 7 in real time.

[0042] In this embodiment, the rotary joint 20, as shown... Figure 2 As shown, the inner shaft 24 of the rotary joint 20 is rotatably mounted in the outer casing 25, and a gap sealing area is formed between the outer wall surface of the inner shaft 24 and the inner wall surface of the outer casing 25. Corresponding to the oil inlet A21 and oil inlet B22, circumferential grooves are formed along the inner shaft 24, which are connected to the holes opened in the axial direction of the inner shaft 24 through the circumferential grooves, so as to realize the actual transfer use of the rotary joint 20 in the rotating state. The outer casing 25 is also provided with an oil return port L23, which is connected to both ends of the gap sealing area. In actual use, some of the oil entering the rotary joint through the oil inlet A21 and oil inlet B22 will be collected in the gap sealing area and flow out through the oil return port L23.

[0043] In the test of this embodiment, the gap seal between the inner shaft 24 and the outer shell 25 of the rotary joint 20 was disassembled into three sections along the axial direction according to the positions of the oil inlet A21 and the oil inlet B22. These sections are: the first section L1 located between the oil inlet A21 and the oil return port L23; the second section L2 located between the oil inlet A21 and the oil inlet B22; and the third section L3 located between the oil inlet B22 and the oil return port L23.

[0044] In this embodiment, two oil inlets and one oil return port on the rotary joint 20 are cleverly used to divide the gap sealing section between the inner shaft 24 and the outer shell 25 of the rotary joint 20 into three sections. Through oil circuit connection and test settings, a comprehensive leakage test of the gap sealing section can be performed, effectively ensuring the sealing performance of the rotary joint and ensuring quality.

[0045] In this embodiment, when the rotary joint 20 is installed in the test system, the end of the inner shaft 24 protruding from the outer shell 25 on the rotary joint 20 can be connected to the output end of the rotation drive power 10. At the same time, the orifice opened on the end face of the inner shaft 24 for normal use of the rotary joint 20 is closed so as to facilitate the sealing performance test of the gap sealing section through the oil inlet A21, oil inlet B22, and oil return L23.

[0046] This embodiment also proposes a test method for a rotary joint test system, including the following tests: Test 1: When oil is only supplied through inlet A21, oil will be returned through inlet B22 and outlet L23 to obtain the oil supply quantity Q at inlet A21. A进 Oil return volume Q at oil inlet B22 B回 Oil return volume Q B回Corresponding to the leakage amount Q2 on the second segment L2, the return oil amount Q at the return port L23 is... L回 Oil intake quantity Q A进 With return oil volume Q B回 The difference, return oil volume Q L回 The leakage amount Q1 corresponds to the first segment L1; Test 2: When oil is only supplied through inlet B22, oil will be returned through inlet A21 and outlet L23 to obtain the oil supply quantity Q at inlet B22. B进 Oil return volume Q at oil inlet A21 A回 Oil return volume Q A回 Corresponding to the leakage amount Q2 on the second segment L2, the return oil amount Q at the return port L23 is... L回 Oil intake quantity Q B进 With return oil volume Q A回 The difference, return oil volume Q L回 The leakage amount Q3 corresponds to the third segment L3; Test 3: When oil is flowing into both inlet A21 and inlet B22, oil will return from outlet L23; obtain the oil flow rate Q at inlet A21. A进 Oil inlet quantity Q at inlet B22 B进 Then the oil return volume Q at return port L23 L回 Oil intake quantity Q A进 With oil intake Q B进 The sum of the oil return volume Q L回 The leakage amount Q corresponds to the first segment L1 and the third segment L3. 1+3 ; The leakage amounts in Test 1 (Q1), Test 2 (Q3), and Test 3 (Q) will be tested. 1+3 Compare each value with a preset value. If all values ​​are less than the preset value, and the sum of the leakage amounts Q1 and Q3 is less than the leakage amount Q... 1+3 If the results are close to the original, the test is passed; otherwise, the test is failed.

[0047] In practice, the order of Test 1, Test 2, and Test 3 is not restricted. After each test, the leakage amount can be compared and judged.

[0048] In practice, the same duration can be set for each test, including Test 1, Test 2, and Test 3. Repeated tests can also be performed to obtain multiple sets of values ​​to ensure the accuracy and reliability of the test.

[0049] In one embodiment, the testing method includes static testing and dynamic testing. During static testing, both the inner shaft 24 and the outer shell 25 are stationary. Tests are performed based on the above-mentioned Test 1, Test 2, and Test 3 to test and judge the rotary joint 20. During dynamic testing, the inner shaft 24 rotates relative to the outer shell 25.

[0050] In the dynamic test, different speeds are set and the tests are conducted according to Test 1, Test 2, and Test 3. If the leakage in the first segment L1, the second segment L2, and the third segment L3 remains basically constant under different speeds and the change is within the acceptable threshold, then the dynamic test is qualified.

[0051] In practice, static testing can be performed first, and dynamic testing can be performed after the static testing is passed.

[0052] In actual operation, before conducting static testing, the rotary joint 20 can be prepared for testing. Oil is simultaneously supplied to the oil inlet A21 and oil inlet B22 by the main oil circuit 1, and oil is returned through the oil return port L23. The test preparation lasts for a preset time, so that the internal contact surface of the rotary joint 20 is initially lubricated by the oil, which satisfies the test conditions.

[0053] For rotary joint 20, its gap sealing performance is theoretically less sensitive to rotational speed. In other words, the leakage of the gap seal does not change much when the rotational speed changes.

[0054] For rotary joint 20, its gap sealing performance is theoretically more sensitive to pressure and temperature than to rotational speed. In other words, changes in pressure and temperature will cause a certain change in the amount of leakage in the gap seal.

[0055] For the rotary joint 20, in practical use, it is applied to an external object by connecting oil inlet A21 and oil inlet B22 to the pipelines supplying oil to and from the external object, respectively, forming a circulating oil circuit connected to the external object. In this embodiment, for testing purposes, the two oil inlets are used as oil inlet / return ports.

[0056] In actual testing, the test pressure and test temperature are usually set, for example, the test is conducted at the working pressure and working temperature of the rotary joint 20.

[0057] In one test, two rotary joints 20 (S1, S2) were tested. Static and dynamic tests were performed respectively. The working pressure was set at 16 MPa, the working temperature was ≤40℃, and the test duration was 300 min.

[0058] Static and dynamic tests were conducted sequentially as follows: Test 1 (A inlet, B outlet), Test 2 (A outlet, B inlet), and Test 3 (both A and B inlet). Here, A is an abbreviation for inlet A21, B is an abbreviation for inlet B22, and Q... A Let Q be the change in oil quantity at point A. B Let Q be the change in oil quantity at point B. L The value represents the change in oil volume at point L; preset reference values ​​for Q1, Q2, and Q3 are all ≤1L / min.

[0059] The static test results are as follows: As can be seen from the above static tests, in the test results of rotary joint S1, Q2=1.5L / min>the preset reference value, therefore rotary joint S1 fails the static test and does not need to be tested dynamically; in the test results of rotary joint S2, all values ​​are less than the preset reference value, and the sum of Q1 and Q3 is less than Q. 1+3 If the results are consistent, then the static test of rotary joint 2S2 is qualified.

[0060] Next, dynamic testing was performed on rotary joint S2, as follows: It can be seen that in the dynamic test results of rotary joint S2, all values ​​are less than the preset reference value, and the sum of Q1 and Q3 is less than Q. 1+3 If the results are consistent, the dynamic test of rotary joint S2 is qualified; therefore, rotary joint S2 is qualified.

[0061] This invention enables the testing of the gap sealing performance of rotary joints, which greatly helps to ensure the gap sealing performance and quality of rotary joints. It is easy to operate and the test is reliable.

[0062] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0063] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A rotary joint testing system, the rotary joint (20) comprising a gap-sealed fitted inner shaft (24), an outer shell (25), the outer shell (25) having an oil inlet A (21), an oil inlet B (22), an oil return L (23) formed therethrough, characterized in that: The test system comprises a test oil circuit (30), the test oil circuit (30) comprises a main oil circuit (1) communicated to an oil tank (7) through a pump (5), the main oil circuit (1) is connected to an oil circuit one (31) and an oil circuit two (32) through a three-way valve (2); the oil circuit one (31) is connected to an oil inlet A (21), and the oil circuit one (31) is laterally connected with an oil return branch A; the oil circuit two (32) is connected to an oil inlet B (22), and the oil circuit two (32) is laterally connected with an oil return branch B; further comprising an oil return branch C connected to an oil return port L (23), the oil return port L (23) is in an oil return state; the oil inlet A (21) and the oil inlet B (22) are both in an oil inlet state, or one is in an oil inlet state and the other is in an oil return state.

2. A rotary union testing system as in claim 1, wherein: The oil inlet amount or the oil return amount of the oil inlet A (21) is obtained by measuring a flow meter one (314) connected in series in the oil circuit one (31), and the oil inlet amount or the oil return amount of the oil inlet B (22) is obtained by measuring a flow meter two (324) connected in series in the oil circuit two (32); when in the oil inlet state, the corresponding flow meter measures the oil inlet amount, when in the oil return state, the corresponding flow meter measures the oil return amount, and the oil return amount is the leakage amount of the corresponding oil inlet.

3. A rotary union testing system as in claim 1, wherein: The rotary joint (20) is supported and fixed to an external platform through a shell (25), the inner shaft (24) is connected to a rotary driving power (10) at the end, the inner shaft (24) is driven to rotate relative to the shell (25) by the rotary driving power (10), and the sealing performance between the shell (25) and the inner shaft (24) is dynamically tested in combination with the oil inlet or oil return setting of the oil inlet A (21) and the oil inlet B (22).

4. A rotary union testing system as in claim 1, wherein: The oil circuit one (31) is connected to the oil inlet A (21) in series with a valve one (311) and a flow meter one (314), and the oil circuit one (31) between the valve one (311) and the flow meter one (314) is laterally connected with an oil return branch A, and the oil return branch A is connected to an oil return one (312) in series with a valve two (313); when the valve one (311) is in a connected state and the valve two (313) is in a disconnected state, the oil inlet A (21) is in an oil inlet state, and vice versa, the oil inlet A (21) is in an oil return state.

5. A rotary union testing system as in claim 1, wherein: The oil circuit two (32) is connected to the oil inlet B (22) in series with a valve three (321) and a flow meter two (324), and the oil circuit two (32) between the valve three (321) and the flow meter two (324) is laterally connected with an oil return branch B, and the oil return branch B is connected to an oil return two (323) in series with a valve four (322); when the valve three (321) is in a connected state and the valve four (322) is in a disconnected state, the oil inlet B (22) is in an oil inlet state, and vice versa, the oil inlet B (22) is in an oil return state.

6. A rotary union testing system as in claim 1, wherein: A pressure sensor one (315) is installed at the oil inlet A (21) for monitoring the pressure at the oil inlet A (21), and a pressure sensor two (325) is installed at the oil inlet B (22) for monitoring the pressure at the oil inlet B (22).

7. A rotary union testing system as in claim 1, wherein: The filter assembly (4) and the one-way valve (3) are connected on the main oil line (1) between the pump (5) and the three-way valve (2); a branch line connected to the oil tank (7) is connected laterally on the main oil line (1) between the pump (5) and the filter assembly (4), and the main circuit valve (9) is connected on the branch line.

8. A rotary union testing system as in claim 1, wherein: An oil cooling machine is further included, and a cooling circuit (40) is connected between the oil tank (7) and the oil cooling machine to cool the oil in the oil tank (7); the oil tank (7) is further provided with a thermometer (6) and a liquid level gauge (8) to monitor the temperature and liquid level of the oil in the oil tank (7) in real time.

9. A method of testing the rotary union test system of claim 1, characterized by: The gap sealing between the inner shaft (24) and the outer shell (25) in the rotary joint (20) is divided into three sections along the axial direction according to the positions of the oil inlet A (21) and the oil inlet B (22), which are the first section (L1) between the oil inlet A (21) and the oil return port L (23), the second section (L2) between the oil inlet A (21) and the oil inlet B (22), and the third section (L3) between the oil inlet B (22) and the oil return port L (23); Test 1: When only the oil inlet A (21) is filled with oil, the oil will be returned from the oil inlet B (22) and the oil return port L (23), and the oil inlet A (21) is filled with oil Q A进 , the oil return amount Q B回 of the oil inlet B (22) B回 Corresponding to the leakage amount Q2 on the second section (L2), the oil return amount Q L回 of the oil return port L (23) is the difference between the oil inlet amount Q A进 and the oil return amount Q B回 , and the oil return amount Q L回 Corresponds to the leakage amount Q1 on the first section (L1); Test two: when only the oil inlet B (22) is filled with oil, the oil return from the oil inlet A (21), the oil return port L (23) is obtained, and the oil inlet B (22) is filled with oil Q B进 , the oil return amount Q A回 of the oil inlet A (21) A回 Corresponding to the leakage amount Q2 on the second section (L2), the oil return amount Q L回 of the oil return port L (23) is the difference between the oil amount Q B进 and the oil return amount Q A回 , and the oil return amount Q L回 Corresponding to the leakage amount Q3 on the third section (L3) Test three: when both inlet A (21) and inlet B (22) are supplied with oil, oil will be returned from the return port L (23); the amount of oil Q A进 supplied at inlet A (21) is obtained B进 , the amount of oil Q L回 supplied at inlet B (22) is obtained A进 , then the amount of oil Q B进 returned at return port L (23) is the sum of the amount of oil Q L回 supplied at inlet A (21) and the amount of oil Q 1+3 supplied at inlet B (22); The leakage Q1 in test one, the leakage Q3 in test two, and the leakage Q 1+3 are compared with preset values respectively. If all of them are less than the preset values, and the sum of the leakage Q1 and the leakage Q3 is close to the leakage Q 1+3 compared, then the test is qualified, otherwise, the test is unqualified.

10. A method of testing a rotary union testing system as defined in claim 9, wherein: The test method includes static testing and dynamic testing, the inner shaft (24) and the outer shell (25) are static during the static testing, and the inner shaft (24) rotates relative to the outer shell (25) during the dynamic testing; different rotating speeds are set in the dynamic testing to perform testing according to test one, test two and test three, and if the leakage amounts on the first section (L1), the second section (L2) and the third section (L3) are basically constant and the change amounts are within an acceptable threshold under different rotating speeds, the dynamic testing is qualified.

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