A test device for testing the reciprocating sealing performance of a sealing ring

Abstract

A test device for testing the reciprocating sealing performance of a sealing ring includes a test cylinder system, an actuating hydraulic system, and a load hydraulic system. The test cylinder system includes a test cylinder, a first piston rod, and a first piston. A first piston chamber is provided in the test cylinder, the first piston rod passes through the test cylinder, a test sealing ring is installed between the first piston rod and the test cylinder, the first piston is slidably installed in the piston chamber, the first piston is located at the end of the first piston rod, the head end of the first piston rod is connected to the load hydraulic system, a force sensor is connected between the first piston rod and the load hydraulic system, the first piston divides the first piston chamber into a first rod chamber and a first rodless chamber of variable volume, the test cylinder is provided with a first interface connecting to the first rod chamber and a second interface connecting to the first rodless chamber, and the actuating hydraulic system is used to drive the first piston rod to reciprocate. The present invention is close to the actual working conditions during testing, which helps to grasp the actual state of the hydraulic cylinder and belongs to the field of hydraulic reciprocating sealing.

Description

Technical Field

[0001] The invention relates to the field of hydraulic reciprocating seals, and in particular to a test device for testing the reciprocating sealing performance of a sealing ring. Background Art

[0002] With the rise of aircraft projects in recent years, related supporting research and experimental work has also begun to be carried out. As the main actuator on the aircraft, aerospace hydraulic actuators are mainly used in aircraft wings and landing gear. They play a very important role in the aircraft's takeoff and landing, as well as in adjusting attitude. The performance of their dynamic seals has an important impact on the safety, reliability, maintainability and life of the actuator and system.

[0003] The seal of an aircraft actuator is a reciprocating seal. In practice, due to heat conduction from the power source, heat generated by throttling, and heat generated by friction, the hydraulic oil temperature can reach as high as 135°C. Therefore, studying the reciprocating seal performance of actuators under high-temperature conditions is of great significance. Existing reciprocating seal performance test equipment mostly uses a through-shaft piston rod. During normal operation, the piston rod seal faces low pressure during the outbound stroke and high pressure during the inbound stroke. However, in a through-shaft configuration, it always faces high pressure during the inbound and outbound strokes, which greatly affects its true characteristics. Such a test cylinder lacks authenticity. Therefore, using a real actuator cylinder is more helpful in understanding the true reciprocating seal performance of the hydraulic cylinder. Summary of the Invention

[0004] In view of the technical problems existing in the prior art, the purpose of the present invention is to provide a reciprocating sealing performance test device for a sealing ring that is close to the actual working state test.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solutions: a test device for testing the reciprocating sealing performance of a sealing ring, comprising a test cylinder system, an actuating hydraulic system, and a load hydraulic system. The test cylinder system includes a test cylinder, a first piston rod, and a first piston; a first piston chamber is defined within the test cylinder, the first piston rod passes through the test cylinder, a test sealing ring is installed between the first piston rod and the test cylinder, the first piston is slidably installed within the first piston chamber, the first piston is located at the end of the first piston rod, the head end of the first piston rod is connected to the load hydraulic system, a force sensor is connected between the first piston rod and the load hydraulic system, the first piston divides the first piston chamber into a first rod chamber and a first rodless chamber of variable volume, the test cylinder is provided with a first interface connecting to the first rod chamber and a second interface connecting to the first rodless chamber; the actuating hydraulic system includes a first oil tank and a first electromagnetic reversing valve, the first interface and the second interface are connected to the first electromagnetic reversing valve via a first pipeline and a second pipeline, respectively, the first oil tank is connected to the first electromagnetic reversing valve via a third pipeline and a fourth pipeline, respectively, the third pipeline is provided with a first filter, a first oil pump, and a first check valve, and the fourth pipeline is provided with a second filter and a first cooler.

[0006] This structure can solve the problem that the working conditions simulated by the through-shaft test cylinder in the existing reciprocating sealing performance test device do not conform to the working conditions normally borne by the seal, and is helpful to grasp the real reciprocating sealing performance of the hydraulic cylinder.

[0007] As a preferred embodiment, the test cylinder includes a cylinder body and end covers located at both ends of the cylinder body, the first piston rod passes through the end covers, and the test sealing ring is located on the inner side of the end covers.

[0008] As a preference, the actuating hydraulic system also includes a first accumulator, a first overflow valve, a first pressure gauge, a first thermometer and a second pressure gauge. The first filter, the first oil pump and the first one-way valve are connected in sequence. The outlet end of the first one-way valve is connected to the first solenoid reversing valve. The outlet end of the first one-way valve is connected to the first accumulator and the inlet end of the first overflow valve. The outlet end of the first overflow valve is connected to the fourth pipeline. The first pressure gauge and the first thermometer are both connected to the first interface, and the second pressure gauge is connected to the second interface.

[0009] As a preferred embodiment, it also includes a heating hydraulic system, the test cylinder is provided with an exhaust hole connected to the first rod chamber, the heating hydraulic system includes a second oil tank and a second solenoid reversing valve, the second oil tank is provided with an oil tank heater, the second solenoid reversing valve includes valve port A, valve port B and valve port C, the second oil tank is connected to valve port B through a first heating pipeline, valve port C is connected to the exhaust hole, an electric three-way valve is provided on the first pipeline, the electric three-way valve is connected to the second oil tank through a second heating pipeline, and a third filter and a second oil pump are provided on the first heating pipeline.

[0010] As a preference, the heating hydraulic system further comprises a second thermometer, which is mounted on the second oil tank, and a pipeline heater and a radiator are provided on the second heating pipeline.

[0011] As a preference, a second overflow valve is connected between the first heating pipeline and the second heating pipeline.

[0012] As a preferred embodiment, the load hydraulic system includes a load cylinder, a second piston, a second piston rod, a third oil tank and a third electromagnetic reversing valve, a second piston chamber is provided in the load cylinder, the second piston rod passes through the load cylinder, the second piston is slidably installed in the second piston chamber, the second piston is located at the end of the second piston rod, the head end of the second piston rod is connected to the force sensor, the second piston divides the second piston chamber into a second rod chamber with a variable volume and a second rodless chamber, and the load cylinder is provided with a third interface connected to the second rod chamber and a fourth interface connected to the second rodless chamber;

[0013] The third interface and the fourth interface are connected to the third solenoid reversing valve through the fifth pipeline and the sixth pipeline respectively, the third oil tank is connected to the third solenoid reversing valve through the seventh pipeline and the eighth pipeline respectively, the seventh pipeline is provided with a fourth filter, a third oil pump and a second one-way valve, and the eighth pipeline is provided with a fifth filter, a second cooler and a fourth overflow valve.

[0014] As a preference, the load hydraulic system also includes a second accumulator and a third overflow valve, the fourth filter, the third oil pump and the second one-way valve are connected in sequence, the outlet end of the second one-way valve is connected to the third solenoid reversing valve, the outlet end of the second one-way valve is connected to the second accumulator and the inlet end of the third overflow valve, and the outlet end of the third overflow valve is connected to the eighth pipeline.

[0015] As a preference, the load hydraulic system further includes a third thermometer and a third pressure gauge, and the third thermometer and the third pressure gauge are both connected to the fourth interface.

[0016] As a preferred embodiment, it also includes a workbench, the test cylinder and the load cylinder are fixedly connected to the workbench, a pull rod displacement sensor is connected between the workbench and the first piston rod, a support ring and a scraper ring are connected between the first piston rod and the test cylinder, and the scraper ring is close to the head end of the first piston rod relative to the test sealing ring.

[0017] In summary, the present invention offers the following advantages: Compared to through-shaft testing, it is more effective in determining the true reciprocating sealing performance of hydraulic cylinders. The heated hydraulic system overcomes the problem of high-temperature oil heated by conventional heating methods failing to reach the interior of the actuator. Furthermore, without changing the actuator's structure, the heated hydraulic system utilizes the actuator's inherent vent holes to achieve heat exchange within the actuator. This method offers advantages such as ease of use, stable operation, accurate testing, and a long service life, and is capable of testing the performance of various seal types. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of a test device for testing the reciprocating sealing performance of a sealing ring.

[0019] Figure 2 This is the structural assembly drawing of the test cylinder and load cylinder.

[0020] Figure 3 This is the schematic diagram of the actuating hydraulic system.

[0021] Figure 4 This is the schematic diagram of the heating hydraulic system.

[0022] Figure 5 This is the schematic diagram of the load cylinder hydraulic system.

[0023] Among them, 100 is a test cylinder, 110 is an end cover, 111 is a scraper ring, 112 is a test seal ring, 113 is a support ring, 114 is an oil leak port, 120 is a first piston rod, 130 is a first piston, 131 is a piston seal ring, 140 is a test cylinder support, 150 is a cylinder body, 151 is a second interface, 160 is a workbench, 170 is a mounting fixture, 171 is a pull rod displacement sensor, 172 is a connecting rod, 180 is a connecting flange, 190 is a force sensor, 200 is an actuating hydraulic system, 201 is a first oil tank, 202 is a first filter, 203 is a first oil pump, 204 is a first one-way valve, 205 is a first accumulator, 206 is a first electromagnetic reversing valve, 207 is a first pressure gauge, 208 is a first thermometer, 209 is an electric three-way valve, 210 is a first overflow Flow valve, 211 is the first cooler, 212 is the second filter, 213 is the second pressure gauge, 300 is the heating hydraulic system, 301 is the second oil tank, 302 is the third filter, 303 is the second oil pump, 304 is the second solenoid reversing valve, 305 is the second overflow valve, 306 is the pipeline heater, 307 is the radiator, 308 is the second thermometer, 309 is the oil tank heater, 400 is the load hydraulic system, 410 is the load cylinder, 420 is the third oil tank, 421 is the fourth filter, 422 is the third oil pump, 423 is the second one-way valve, 424 is the second accumulator, 425 is the third solenoid reversing valve, 426 is the third pressure gauge, 427 is the third thermometer, 428 is the third overflow valve, 429 is the fourth overflow valve, 430 is the second cooler, and 431 is the fifth filter. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example 1

[0026] like Figures 1 to 3As shown, a test device for testing the reciprocating sealing performance of a sealing ring includes a test cylinder system, an actuating hydraulic system and a load hydraulic system. The test cylinder system includes a test cylinder, a first piston rod and a first piston; a first piston chamber is provided in the test cylinder, the first piston rod passes through the test cylinder, a test sealing ring is installed between the first piston rod and the test cylinder, the first piston is slidably installed in the first piston chamber, the first piston is located at the end of the first piston rod, the head end of the first piston rod is connected to the load hydraulic system, a force sensor is connected between the first piston rod and the load hydraulic system, the first piston divides the first piston chamber into a first rod chamber and a first rodless chamber with a variable volume, the test cylinder is provided with a first interface connecting to the first rod chamber and a second interface connecting to the first rodless chamber; the actuating hydraulic system includes a first oil tank and a first electromagnetic reversing valve, the first interface and the second interface are connected to the first electromagnetic reversing valve through a first pipeline and a second pipeline respectively, the first oil tank is connected to the first electromagnetic reversing valve through a third pipeline and a fourth pipeline respectively, the third pipeline is provided with a first filter, a first oil pump and a first check valve, and the fourth pipeline is provided with a second filter and a first cooler.

[0027] The first oil pump is a high-pressure pump, and the test seal ring can adopt various forms to test the sealing performance of different seal rings.

[0028] The test cylinder includes a cylinder body and end caps at both ends of the cylinder body. The first piston rod passes through the end caps, and the test seal ring is located on the inner side of the end caps. The first and second interfaces are both located on the side of the cylinder body, and the end caps have oil leakage holes to collect leaked liquid.

[0029] The actuating hydraulic system also includes a first accumulator, a first relief valve, a first pressure gauge, a first thermometer and a second pressure gauge. The first filter, the first oil pump and the first one-way valve are connected in sequence. The outlet end of the first one-way valve is connected to the first solenoid reversing valve. The outlet end of the first one-way valve is connected to the first accumulator and the inlet end of the first relief valve. The outlet end of the first relief valve is connected to the fourth pipeline. The first pressure gauge and the first thermometer are both connected to the first interface, and the second pressure gauge is connected to the second interface.

[0030] The first accumulator serves as an auxiliary power source to supplement leakage and maintain constant pressure.

[0031] like Figure 4 As shown, it also includes a heating hydraulic system. The test cylinder is provided with an exhaust hole connected to the first rod chamber. The heating hydraulic system includes a second oil tank and a second solenoid reversing valve. The second oil tank is provided with an oil tank heater. The second solenoid reversing valve includes valve port A, valve port B and valve port C. The second oil tank is connected to valve port B through a first heating pipeline, and valve port C is connected to the exhaust hole. An electric three-way valve is provided on the first pipeline, and the electric three-way valve is connected to the second oil tank through a second heating pipeline. A third filter and a second oil pump are provided on the first heating pipeline.

[0032] The A valve port is connected to a cut-off switch. After the device is installed, the C valve port of the second solenoid reversing valve is connected to the A valve port, and the cut-off switch connected to the A valve port is opened. The exhaust hole is in the exhaust function, and the air in the system is discharged through the exhaust hole. When the C valve port is connected to the B valve port, the exhaust hole participates in the oil heating cycle.

[0033] The second oil pump is a high-temperature pump. The electric three-way valve includes a first valve port, a second valve port, and a third valve port. The first valve port is connected to the first solenoid reversing valve, the second valve port is connected to the first interface, and the third valve port is connected to the second heating pipeline. The test cylinder system has an actuated state and a heated state. In the actuated state, the first valve port and the second valve port are connected. In the heated state, the first valve port and the third valve port are connected.

[0034] The heating hydraulic system further comprises a second thermometer which is mounted on the second oil tank, and a pipeline heater and a radiator are arranged on the second heating pipeline.

[0035] A second overflow valve is connected between the first heating pipeline and the second heating pipeline.

[0036] like Figure 5 As shown, the load hydraulic system includes a load cylinder, a second piston, a second piston rod, a third oil tank and a third electromagnetic reversing valve. A second piston chamber is provided in the load cylinder. The second piston rod passes through the load cylinder. The second piston is slidably installed in the second piston chamber. The second piston is located at the end of the second piston rod. The head end of the second piston rod is connected to the force sensor. The second piston divides the second piston chamber into a second rod chamber with a variable volume and a second rodless chamber. The load cylinder is provided with a third interface connected to the second rod chamber and a fourth interface connected to the second rodless chamber; the third interface and the fourth interface are connected to the third electromagnetic reversing valve through the fifth pipeline and the sixth pipeline respectively, the third oil tank is connected to the third electromagnetic reversing valve through the seventh pipeline and the eighth pipeline respectively, the seventh pipeline is provided with a fourth filter, a third oil pump and a second one-way valve, and the eighth pipeline is provided with a fifth filter, a second cooler and a fourth overflow valve.

[0037] The third oil pump is a low-pressure pump, which is used to replenish oil to the load cylinder hydraulic system. The third overflow valve is used to maintain the minimum load.

[0038] The second piston rod is coaxially arranged with the first piston rod and is respectively connected to a force sensor via a connecting flange, and performs reciprocating motion under the action of the actuating hydraulic system.

[0039] The load hydraulic system also includes a second accumulator and a third overflow valve. The fourth filter, the third oil pump and the second one-way valve are connected in sequence. The outlet end of the second one-way valve is connected to the third solenoid reversing valve. The outlet end of the second one-way valve is connected to the second accumulator and the inlet end of the third overflow valve. The outlet end of the third overflow valve is connected to the eighth pipeline.

[0040] The load hydraulic system further includes a third thermometer and a third pressure gauge, and both the third thermometer and the third pressure gauge are connected to the fourth interface.

[0041] The apparatus also includes a workbench, to which the test cylinder and the load cylinder are fixedly connected. A pull-rod displacement sensor is connected between the workbench and the first piston rod. A support ring and a scraper ring are connected between the first piston rod and the test cylinder. The scraper ring is located closer to the head end of the first piston rod than the test seal ring. The support ring serves as a support and guide.

[0042] The tie-rod displacement sensor is located below the first piston rod and secured to the workbench via a mounting fixture. The tie-rod displacement sensor is parallel to the first piston rod. Its core is connected to the sidewall of the first piston rod via its connecting rod, allowing it to reciprocate synchronously with the first piston rod. Both ends of the cylinder body are secured to the workbench via test cylinder supports.

[0043] Grooves are formed on the outside of the first piston and the second piston, piston sealing rings are installed in the grooves, and the first piston and the end of the first piston rod, as well as the second piston and the end of the second piston rod are both connected through threads.

[0044] The working process of the reciprocating sealing performance test device of the above sealing ring is as follows.

[0045] When measuring the performance of the sealing ring, first control the electric three-way valve to the state where the second and third valve ports are connected. At this time, the test cylinder is in the heating state. At the same time, adjust the second solenoid reversing valve to connect valve port C with valve port B. At this time, the exhaust hole of the test cylinder is in the oil heating function. The oil in the first piston chamber participates in the oil circulation of the entire heating hydraulic system, and the high-temperature oil fills the first piston chamber. When the oil temperature measured by the first thermometer reaches the specified temperature, the heating ends. Then, the electric three-way valve is placed in the state where the first and second valve ports are connected. At this time, the test cylinder is in the actuating state. At the same time, connect valve port C with valve port A of the second solenoid reversing valve, and open and close the cut-off valve connected to valve port A. Then, oil flows into the first rodless chamber of the test cylinder through the actuating hydraulic system, and returns oil to the rod chamber. At the same time, the fourth relief valve acts as a back pressure valve to bear the load force of the test cylinder to realize the actuation of the test cylinder. Then, the reciprocating motion of the test cylinder is realized by continuously reversing the first solenoid reversing valve. The load forces on the test cylinder in the two states of the out-stroke and in-stroke are respectively:

[0046] F o =P b ×S1-P s ×S2

[0047] F i =P s ×S2-P b ×S1

[0048] Finally, the friction force on the test seal ring during the in-and-out stroke is:

[0049] f o =P1×S1-P2×S2-F

[0050] f i =P2×S2-P1×S1-F

[0051] like Figure 4 、 5 As shown, F in the above formula o F is the load force on the test cylinder during the stroke; i P is the load force on the test cylinder when it enters the stroke; b is the outlet pressure of the low-pressure pump, i.e. the set pressure of the third relief valve; P s is the set pressure of the fourth relief valve; f o f is the friction force on the seal ring when the test cylinder is in the out stroke; i It is the friction force exerted on the test seal ring when the test cylinder enters the stroke; P1 is the pressure of the first rodless chamber, S1 is the area of ​​the rodless chamber (the first and second rodless chamber areas are the same), P2 is the pressure of the first rod chamber, S2 is the area of ​​the rod chamber (the first and second rod chamber areas are the same), and F is the force sensor value.

[0052] The above embodiments are preferred implementations of the invention, but the implementation of the present invention is not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A test device for testing the reciprocating sealing performance of a sealing ring, characterized by: It includes a test cylinder system, an actuating hydraulic system and a load hydraulic system. The test cylinder system includes a test cylinder, a first piston rod and a first piston; A first piston chamber is provided in the test cylinder, a first piston rod passes through the test cylinder, a test sealing ring is installed between the first piston rod and the test cylinder, a first piston is slidably installed in the first piston chamber, the first piston is located at the end of the first piston rod, the head end of the first piston rod is connected to the load hydraulic system, a force sensor is connected between the first piston rod and the load hydraulic system, the first piston divides the first piston chamber into a first rod chamber with a variable volume and a first rodless chamber, and the test cylinder is provided with a first interface connected to the first rod chamber and a second interface connected to the first rodless chamber; The actuating hydraulic system includes a first oil tank and a first solenoid reversing valve, wherein the first interface and the second interface are connected to the first solenoid reversing valve via a first pipeline and a second pipeline respectively, the first oil tank is connected to the first solenoid reversing valve via a third pipeline and a fourth pipeline respectively, the third pipeline is provided with a first filter, a first oil pump and a first check valve, and the fourth pipeline is provided with a second filter and a first cooler; The actuating hydraulic system further includes a first accumulator, a first relief valve, a first pressure gauge, a first thermometer, and a second pressure gauge; a first filter, a first oil pump, and a first one-way valve are connected in sequence; an outlet end of the first one-way valve is connected to a first solenoid reversing valve; an outlet end of the first one-way valve is connected to the first accumulator and an inlet end of the first relief valve; an outlet end of the first relief valve is connected to a fourth pipeline; a first pressure gauge and a first thermometer are both connected to a first port; and a second pressure gauge is connected to a second port. It also includes a heated hydraulic system, wherein the test cylinder is provided with an exhaust hole connected to the first rod chamber, the heated hydraulic system includes a second oil tank and a second electromagnetic reversing valve, the second oil tank is provided with an oil tank heater, the second electromagnetic reversing valve includes valve ports A, B, and C, the second oil tank is connected to valve port B through a first heating pipeline, and valve port C is connected to the exhaust hole, an electric three-way valve is provided on the first pipeline, and the electric three-way valve is connected to the second oil tank through a second heating pipeline, and the first heating pipeline is provided with a third filter and a second oil pump; The load hydraulic system includes a load cylinder, a second piston, a second piston rod, a third oil tank and a third electromagnetic reversing valve. The load cylinder is provided with a second piston chamber. The second piston rod passes through the load cylinder. The second piston is slidably installed in the second piston chamber. The second piston is located at the end of the second piston rod. The head end of the second piston rod is connected to a force sensor. The second piston divides the second piston chamber into a second rod chamber with a variable volume and a second rodless chamber. The load cylinder is provided with a third interface connected to the second rod chamber and a fourth interface connected to the second rodless chamber. The third interface and the fourth interface are connected to the third solenoid reversing valve through the fifth pipeline and the sixth pipeline respectively, the third oil tank is connected to the third solenoid reversing valve through the seventh pipeline and the eighth pipeline respectively, the seventh pipeline is provided with a fourth filter, a third oil pump and a second one-way valve, and the eighth pipeline is provided with a fifth filter, a second cooler and a fourth overflow valve.

2. A reciprocating sealing performance test device for a sealing ring according to claim 1, characterized in that: The test cylinder comprises a cylinder body and end covers located at both ends of the cylinder body, the first piston rod passes through the end covers, and the test sealing ring is located on the inner side of the end covers.

3. A reciprocating sealing performance testing device for a sealing ring according to claim 1, characterized in that: The heating hydraulic system further comprises a second thermometer which is mounted on the second oil tank, and a pipeline heater and a radiator are arranged on the second heating pipeline.

4. A reciprocating sealing performance testing device for a sealing ring according to claim 1, characterized in that: A second overflow valve is connected between the first heating pipeline and the second heating pipeline.

5. A reciprocating sealing performance testing device for a sealing ring according to claim 1, characterized in that: The load hydraulic system also includes a second accumulator and a third overflow valve. The fourth filter, the third oil pump and the second one-way valve are connected in sequence. The outlet end of the second one-way valve is connected to the third solenoid reversing valve. The outlet end of the second one-way valve is connected to the second accumulator and the inlet end of the third overflow valve. The outlet end of the third overflow valve is connected to the eighth pipeline.

6. A reciprocating sealing performance testing device for a sealing ring according to claim 1, characterized in that: The load hydraulic system further includes a third thermometer and a third pressure gauge, and both the third thermometer and the third pressure gauge are connected to the fourth interface.

7. A reciprocating sealing performance testing device for a sealing ring according to claim 1, characterized in that: It also includes a workbench, the test cylinder and the load cylinder are fixedly connected to the workbench, a pull rod displacement sensor is connected between the workbench and the first piston rod, a support ring and a scraper ring are connected between the first piston rod and the test cylinder, and the scraper ring is close to the head end of the first piston rod relative to the test sealing ring.

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