CN114705555A - Dry gas seal axial air film rigidity testing device based on closing force fine adjustment - Google Patents

Abstract

The invention discloses a dry gas seal axial gas film stiffness test device based on fine adjustment of closing force, comprising a dry gas seal pair, a sealing cavity assembly, and a spring compression amount regulating assembly, wherein the sealing cavity assembly includes a main sealing cavity , Auxiliary sealing cavity, stationary ring bushing, the dry gas sealing pair includes a sealing dynamic ring fixedly mounted on the rotating shaft and a sealing static ring flexibly mounted on the stationary ring bushing, the inner diameter of the sealing dynamic ring is fixed with an induction ring The inner diameter of the sealing static ring is fixed with a first displacement sensor, and the spring compression control assembly includes a spring seat, a first force sensor seat, a force sensor, and a second force sensor seat in sequence from the compression spring. The spring The compression amount regulating assembly is axially movable to adjust the compression amount of the compression spring. The invention realizes the on-line regulation of the closing force of the dry gas seal compensation ring and the on-line test of the seal opening force and the thickness of the gas film by fine-tuning the spring compression amount, and can realize the axial gas film of the dry gas seal under different working conditions and gas film thickness. The stiffness test has the advantages of convenient adjustment and high test accuracy.

Description

A Dry Gas Seal Axial Air Film Stiffness Testing Device Based on Closing Force Fine Tuning

technical field

The invention relates to the field of a dry gas seal performance test device, in particular to a dry gas seal axial gas film stiffness test device.

Background technique

The axial air film stiffness of dry gas seals is defined as the absolute value of the ratio of the axial perturbation force on the end face of the seal compensation ring to the corresponding change in the thickness of the sealing air film. It is an important performance parameter reflecting its ability to resist external axial disturbances. . The greater the axial air film stiffness, the smaller the change in air film thickness of the dry gas seal under the same external disturbance force, and the more stable the air film thickness. The dry gas seal axial gas film stiffness test involves the construction, testing and testing of the gas film thickness on the sealing end face with small changes in the closing force of the seal compensation ring. The thickness of the sealing gas film can generally be measured by an eddy current sensor, and it is a difficult problem to realize the construction and test of the small change of the closing force of the sealing compensation ring under the condition of belt speed and pressure.

The existing gas thrust bearing axial gas film stiffness testing device tests the bearing clearance through the eddy current sensor, changes the axial load acting on the thrust bearing by changing the mass of the weight or adjusting the screw, and passes the test between the gas bearing and the load. The axial load is measured by the inter-connected force sensor, but the test device has no external pressure chamber, and the two thrust bearing bodies are in a non-rotating state, that is, the axial air film stiffness test under external pressure and speed conditions cannot be achieved. The existing dry gas seal axial gas film stiffness testing device tests the sealing gap through an eddy current sensor, and adjusts the displacement of the static ring by installing a plurality of helical micrometer heads evenly distributed in the circumferential direction on the back of the static ring, thereby changing the back of the flexible installation dynamic ring However, the adjustment of the closing force in this device needs to be performed after the speed is stopped and the pressure is released, and the uneven adjustment of multiple helical micrometer heads will easily cause the installation of the static ring. skewed. It can be seen that the existing gas-lubricated thrust bearing and dry gas-seal axial gas film stiffness testing devices still have the problem that the axial load cannot be adjusted under the conditions of belt speed and external cavity pressure, and the sealing ring is easy to deflect during the adjustment process, etc. question.

SUMMARY OF THE INVENTION

The present invention aims to overcome the problem of inability to adjust the axial load under the conditions of belt speed and external cavity belt pressure in the existing gas lubricated thrust bearing and dry gas seal axial gas film stiffness test. Under the condition of belt speed and pressure, the device can realize the axial air film stiffness test of dry gas seal by fine-tuning the sealing force.

The technical scheme of the present invention is as follows:

A dry gas seal axial gas film stiffness test device based on fine adjustment of closing force, comprising a sealing cavity assembly, a dry gas sealing pair arranged in the sealing cavity assembly, and a spring compression amount regulating component on the sealing cavity assembly, so The sealing cavity assembly includes a main sealing cavity, an auxiliary sealing cavity connected with the main sealing cavity, and a stationary ring sleeve arranged on the auxiliary sealing cavity, and the dry gas sealing pair includes a sealing fixedly installed on the rotating shaft A moving ring and a sealing static ring flexibly mounted on the stationary ring shaft sleeve, the inner diameter of the sealing dynamic ring is fixed with a sensing plate, the inner diameter of the sealing static ring is fixed with a first displacement sensor, and the spring compression amount control assembly includes sequentially arranged A compression spring, a spring seat, a first force sensor seat, a force measuring sensor and a second force sensor seat are provided, and the spring compression amount regulating assembly can move axially to realize the adjustment of the compression spring compression amount.

Further, the spring compression amount control assembly further includes an auxiliary push ring, a flat head pin, a first thrust bearing seat, a thrust bearing, a second thrust bearing seat, a handle connector and a rotating handle, and the second thrust bearing seat is connected with the rotating handle. The auxiliary seal shaft sleeves are connected by threads, the auxiliary push ring is located in the auxiliary seal cavity, and the flat head pin passes through the pin hole on the static ring shaft sleeve.

Further, the main sealing cavity and the auxiliary sealing cavity are fastened and connected by a first bolt, and the auxiliary sealing cavity and the stationary ring bushing are fastened and connected by a second bolt.

Further, a first auxiliary sealing ring is arranged radially between the first force sensor seat and the stationary ring sleeve, and a second auxiliary sealing ring is arranged radially between the first force sensor seat and the auxiliary sealing cavity.

Further, an auxiliary positioning ring is arranged radially between the second force sensing seat and the auxiliary sealing cavity, and the auxiliary positioning ring is fixed on the auxiliary sealing cavity.

Further, a second displacement sensor is installed on the first thrust bearing seat.

Further, a push ring is provided between the sealing static ring and the compression spring, and a fifth auxiliary sealing ring is provided between the push ring and the stationary ring shaft sleeve.

Further, the auxiliary sealing cavity is provided with an air intake hole, and a pressure regulating cavity is formed between the auxiliary sealing cavity, the stationary ring shaft sleeve, the second force sensor seat and the auxiliary positioning ring, and the air intake hole is connected to the auxiliary locating ring. The pressure regulating chamber is communicated.

Further, a third auxiliary sealing ring is arranged radially between the auxiliary positioning ring and the second force sensor seat, and a fourth auxiliary sealing ring is arranged radially between the auxiliary positioning ring and the auxiliary sealing cavity.

Further, the diameter of the first outer peripheral surface of the first force sensor seat is equal to the outer diameter of the sealing end surface of the sealing static ring, in order to ensure that the measured value of the load cell can be equal to the opening force of the sealing end surface.

The beneficial effects of the present invention are as follows:

1) The overall axial movement of the spring compression control component is controlled by external air pressure adjustment or mechanical handwheel adjustment to change the spring compression amount, thereby realizing the adjustment of the sealing closing force, and can carry out dry gas under the conditions of pressure and speed of the external cavity medium Continuous adjustment of the closing force of the sealing end face, and the adjustment process will not cause additional installation deflection of the sealing dynamic and static rings.

2) Through the reasonable design of the outer diameter of the load cell seat and the spring mounting seat, and the friction force of each auxiliary seal ring is calibrated in advance, the seal opening force can be accurately calculated by the load cell reading, which improves the dry gas seal shaft. Test accuracy towards air film stiffness.

Description of drawings

1 is a cross-sectional view of a dry gas seal axial gas film stiffness testing device according to Embodiment 1 of the present invention;

FIG. 2 is a schematic structural diagram of the spring compression amount control assembly according to the first embodiment of the present invention;

3 is a schematic structural diagram of a dry gas seal gas film thickness test according to an embodiment of the present invention;

4 is a schematic diagram of the axial force analysis of the dry gas seal static ring according to an embodiment of the present invention;

5 is a cross-sectional view of a dry gas seal axial gas film stiffness testing device according to Embodiment 2 of the present invention;

FIG. 6 is a schematic structural diagram of the spring compression amount control assembly according to the second embodiment of the present invention;

In the figure: 1. Dry gas sealing pair; 11. Sealing dynamic ring; 111. Induction sheet; 12. Sealing static ring; 121. The first displacement sensor; 122, The first displacement sensor seat; Cavity assembly; 21, main sealing cavity; 212, first bolt; 22, auxiliary sealing cavity; 221, second bolt; 222, auxiliary positioning ring; 223, air inlet; 224, pressure regulating cavity; 225, 4th auxiliary seal ring; 23, stationary ring bushing; 3, spring compression control assembly; 31, compression spring; 311, push ring; 312, fifth auxiliary seal ring; 32, spring seat; 33, first force sensor seat; 331, the first auxiliary sealing ring; 332, the second auxiliary sealing ring; 333, the first outer peripheral surface; 34, the load cell; 35, the second force sensor seat; 351, the third auxiliary sealing ring; 36, the auxiliary Push ring; 37, flat head pin; 381, first thrust bearing seat; 382, thrust bearing; 383, second thrust bearing seat; 384, second displacement sensor; 391, handle connector; 392, rotating handle; 4, rotating shaft .

Detailed ways

The implementation of the present invention will be further described in detail below with reference to the accompanying drawings.

Example 1:

Referring to Figures 1, 2, and 3, a dry gas seal axial gas film stiffness test device based on fine adjustment of closing force includes a dry gas seal pair 1, a sealed cavity assembly 2, a spring compression control assembly 3, and a dry gas seal pair. The sealing pair 1 includes a sealing ring 11 fixedly installed on the rotating shaft 41 and a sealing static ring 12 flexibly installed on the static ring shaft sleeve 23 . A first displacement sensor seat 122 is installed on the inner diameter. The first displacement sensor 121 is fixedly installed on the first displacement sensor seat 122. Through the combined use of the induction sheet 111 and the first displacement sensor 121, the sealing dynamic ring 11 and the sealing static ring can be measured. The sealing gap h between 12.

The sealing cavity assembly 2 includes a main sealing cavity 21 , a secondary sealing cavity 22 and a stationary ring bushing 23 . The main sealing cavity 21 and the auxiliary sealing cavity 22 are fastened and connected by the first bolts 212 , and the auxiliary sealing cavity 22 and the stationary ring bushing 23 are fastened and connected by the second bolts 221 .

The spring compression amount control assembly 3 includes a compression spring 31, a spring seat 32, a first force sensor seat 33, a force sensor 34, and a second force sensor seat 35 in sequence from the side of the compression spring 31, and can be moved axially to realize the compression spring. 31 Adjustment of the amount of compression. In order to construct the pressure chamber on the back of the sealed static ring 12 , a first auxiliary seal ring 331 is arranged radially between the first force sensor seat 33 and the static ring shaft sleeve 23 , and the first force sensor seat 33 is radially between the auxiliary seal cavity 22 . A second auxiliary sealing ring 332 is provided. A push ring 31 is provided between the sealing static ring 12 and the compression spring 31 , and a fifth auxiliary sealing ring 312 is provided between the push ring 311 and the static ring shaft sleeve 23 . An auxiliary positioning ring 222 is provided radially between the second force sensing seat 35 and the auxiliary sealing cavity 22 , and the auxiliary positioning ring 222 is fixed on the auxiliary sealing cavity 22 by a set screw.

The adjustment of the compression amount of the compression spring 31 is a mechanical drive scheme, that is, the spring compression amount compression assembly 3, starting from the second force sensor seat 35, also includes an auxiliary push ring 36, a flat pin 37, a first thrust bearing seat 381, and a thrust bearing. 382 , the second thrust bearing seat 383 , the handle connecting piece 391 , the rotating handle 392 . The second thrust bearing seat 383 and the stationary ring bushing 23 are connected by threads, the auxiliary push ring 36 is located in the auxiliary seal cavity 22, the flat head pin 37 passes through the pin hole on the stationary ring bushing 23, and the rotary handle 392 is rotated. The second thrust bearing seat 383 can be driven to continuously screw on the threaded section of the stationary ring bushing 23, thereby driving the first thrust bearing seat 381, the flat pin 37, and the auxiliary push ring 36 to move in the axial direction. In order to monitor the compression amount of the compression spring 31 , a second displacement sensor 384 is installed on the first thrust bearing seat 381 .

Referring to FIG. 4 , the opening force of the seal end face is F _o , the air pressure force of the medium pressure in the back cavity of the seal static ring 12 on the left push ring 31 and the air pressure force on the right first force sensor seat 33 are F _sta1 and F _sta2 , the spring force of the compression spring 31 to the left push ring 31 and the spring force of the right spring seat 32 are F _sp1 and F _sp2 respectively, the friction force of the fifth auxiliary seal ring 312 between the push ring 311 and the stationary ring sleeve 23 , the friction force of the second auxiliary seal ring 332 between the first force sensor seat 33 and the auxiliary seal cavity 22 , and the friction force of the first auxiliary seal ring 331 between the first force sensor seat 33 and the static ring sleeve 23 are respectively F _f1 , F _f2 and F _f3 , the test value of the load cell 34 is F1. According to the principle of equal action force and reaction force, it can be known that the spring force F _sp1 =F _sp2 , and the air pressure force F _sta1 =F _sta2 . When the closing force increases by increasing the compression amount of the compression spring 31, the air-film gap gradually becomes smaller, the friction force F _f1 received by the push ring 31 is rightward, and the friction forces F _f2 and F _f3 received by the first force sensor seat 33 Also to the right. Taking the sealing static ring 12 and the push ring 31 as the force objects, they are subjected to the rightward end face opening force F _o and the friction force F _f1 , and the leftward air pressure force F _sta1 and the spring force F _sp1 , so there is a force balance. The formula F _o +F _f1 =F _sta1 +F _sp1 . Taking the spring seat 32 and the first force sensor seat 33 as the force-bearing objects, they are subjected to the rightward air pressure force F _sta2 , the spring force F _sp2 , the frictional forces F _f2 and F _f3 , and are supported by the leftward force sensor 34 F ₁ , there is a force balance formula F ₁ =F _sta2 +F _sp2 +F _f2 +F _f3 . According to the above two force balance formulas, the sealing opening force F _o =F ₁ -(F _f1 +F _f2 +F _f3 ) can be obtained, wherein F ₁ can be measured by the load cell 34, and the auxiliary sealing ring friction force F _f1 , F _f2 and F _f3 can be obtained by calibration before the test, and on this basis, the sealing end face opening force F _o can be obtained. Conversely, when the closing force is reduced by continuously reducing the compression amount of the compression spring 32 and the air-film gap is gradually increased, the sealing opening force F _o = F ₁ +(F _f1 +F _f2 +F _f3 ) can be obtained. Accurately measuring the seal opening force F _o under different conditions is the key to accurately obtain the axial film stiffness of the dry gas seal.

Example 2:

5 and 6, the difference between this embodiment and the first embodiment is that the second force sensor seat 35 in the spring compression amount compression assembly 3 does not have the auxiliary push ring 36, the flat head pin 37 and the first thrust bearing seat at the beginning. 381, thrust bearing 382, second thrust bearing seat 383, handle connector 391, rotating handle 392, but between the auxiliary seal cavity 22, the stationary ring bushing 23, the second force sensor seat 35 and the auxiliary positioning ring 222 A pressure regulating cavity 224 is formed, a third auxiliary sealing ring 351 is arranged radially between the auxiliary positioning ring 222 and the second force sensor seat 35, and a fourth auxiliary sealing ring 225 is arranged radially between the auxiliary positioning ring 222 and the auxiliary sealing cavity 22; An air inlet hole 223 is provided on the auxiliary sealing cavity, and the air inlet hole 223 is communicated with the pressure regulating chamber 224. By passing the pressurized gas into the air inlet hole 223, the gas pressure F ₂ is used to adjust the spring compression amount control component 3, the rest of the structure and the embodiment are the same as the first embodiment.

The working principle is:

The test of the axial air film stiffness involves the test of the dry gas seal gap h and the opening force F _o . A set of dry gas sealing pair is installed in the main sealing cavity, in which the sealing dynamic ring is fixedly installed on the rotating shaft, the sealing static ring is flexibly installed on the static ring shaft sleeve, an induction sheet is installed on the inner diameter of the sealing dynamic ring, and the inner diameter of the sealing static ring is installed There is a first displacement sensor, and the sealing gap h between the sealing dynamic ring and the sealing static ring can be measured through the cooperation of the first displacement sensor with the induction sheet. The adjustment of the closing force F _c of the sealing end face is achieved by adjusting the spring compression of the back of the sealing static ring through the overall axial movement of the spring compression amount regulating assembly. There are two schemes for the axial movement of the spring compression control assembly, namely mechanical adjustment and pneumatic adjustment. For the mechanical adjustment scheme, the rotation of the rotary handle can drive the axial movement of the second thrust bearing seat, the thrust bearing, and the first thrust bearing seat, which are connected to the stationary ring bushing through threads, and then pass through the stationary ring shaft. The flat-headed pin covered with the pin hole drives the auxiliary push ring located in the auxiliary seal cavity to move axially, and then drives the axial movement of the second force sensor seat, the force sensor, the first force sensor seat and the spring seat, and finally realizes the axial movement of the spring On-line regulation of the compression amount; and a second displacement sensor is installed on the first thrust bearing seat, which can measure the axial movement amount of the spring compression amount regulation component. For the air pressure adjustment scheme, pressurized gas is introduced into the pressure chamber formed between the auxiliary seal cavity, the stationary ring bushing, the second force sensor seat and the auxiliary positioning ring through the air inlet hole on the auxiliary sealing cavity, Adjust the pressure to realize the axial movement of the second force sensor seat, the load cell, the first force sensor seat and the spring seat, change the spring compression and then adjust the closing force F _c of the sealing end face. A load cell is installed between the first force sensor seat and the second force sensor seat, which can test the spring force and medium pressure in the back cavity of the sealed static ring; the value of the axial force measured by the load cell and before the test The calibrated friction force of each auxiliary sealing ring can be calculated to obtain the opening force F _o of the sealing end face.

When the test device is used to test the axial air film stiffness of dry gas seals, firstly, the seal opening force F _o1 and the seal gap h ₁ are measured by adjusting the amount of spring compression; Change the spring compression amount, and then change the closing force F _c of the sealing static ring, and measure the sealing opening force F _o2 and the sealing gap h ₂ at this time, then the axial air film stiffness is k=(F _o1 -F _o2 )/ (h ₂ -h ₁ ) is calculated.

The content described in the embodiments of the present specification is only an enumeration of the realization forms of the inventive concept, and the protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments, and the protection scope of the present invention also extends to those skilled in the art. Equivalent technical means that can be thought of by a person based on the inventive concept.

Claims (10)

1. A dry gas seal axial gas film stiffness testing device based on fine adjustment of closing force, characterized in that it comprises a sealing cavity assembly (2), a dry gas sealing pair (1) arranged in the sealing cavity assembly (2) ) and a spring compression control assembly (3) on the sealing cavity assembly (2), the sealing cavity assembly (2) comprising a main sealing cavity (21) and a secondary seal connected to the main sealing cavity (21) A cavity (22) and a stationary ring shaft sleeve (23) arranged on the auxiliary sealing cavity (22), the dry gas sealing pair (1) includes a sealing ring (11) fixedly installed on the rotating shaft (4) and a sealing static ring (12) flexibly installed on the static ring shaft sleeve (23), the inner diameter of the sealing dynamic ring (11) is fixed with an induction plate (111), and the inner diameter of the sealing static ring (12) is fixed with a first Displacement sensor (121), the spring compression amount control assembly (3) includes a compression spring (31), a spring seat (32), a first force sensor seat (33), a load cell (34) and a second force sensor (34) arranged in sequence The force sensor seat (35), the spring compression amount regulating component (3) can be moved axially to realize the adjustment of the compression amount of the compression spring (31). 2. A dry gas seal axial air film stiffness test device based on fine adjustment of closing force according to claim 1, characterized in that, the spring compression amount control assembly (3) further comprises an auxiliary push ring (36) in sequence , flat head pin (37), first thrust bearing seat (381), thrust bearing (382), second thrust bearing seat (383), handle connector (391) and rotating handle (392), the second thrust bearing The seat (383) and the auxiliary seal sleeve (23) are connected by threads, the auxiliary push ring (36) is located in the auxiliary seal cavity (22), and the flat head pin (37) passes through the static ring sleeve ( 23) on the pin hole. 3. A dry gas seal axial gas film stiffness test device based on fine adjustment of closing force according to claim 1, characterized in that, between the main sealing cavity (21) and the auxiliary sealing cavity (22) The first bolts (212) are used for fast connection, and the second bolts (221) are used to fasten the connection between the auxiliary sealing cavity (22) and the stationary ring shaft sleeve (23). 4. A dry gas seal axial air film stiffness test device based on fine adjustment of closing force according to claim 1, characterized in that the diameter of the first force sensor seat (33) and the static ring bushing (23) is A first auxiliary sealing ring (331) is arranged in the radial direction, and a second auxiliary sealing ring (332) is arranged radially between the first force sensor seat (33) and the auxiliary sealing cavity (22). 5. A dry gas seal axial air film stiffness testing device based on fine adjustment of closing force according to claim 1, characterized in that the second force sensing seat (35) and the auxiliary sealing cavity (22) An auxiliary positioning ring (222) is arranged between the radial directions, and the auxiliary positioning ring (222) is fixed on the auxiliary sealing cavity (22). 6. A dry gas seal axial air film stiffness test device based on fine adjustment of closing force according to claim 2, wherein a second displacement sensor (384) is installed on the first thrust bearing seat (381) ). 7. A dry gas seal axial air film stiffness test device based on fine adjustment of closing force according to claim 3, characterized in that a pusher is provided between the sealing static ring (12) and the compression spring (31). The ring (311) is provided with a fifth auxiliary sealing ring (312) between the push ring (311) and the stationary ring shaft sleeve (23). 8 . The dry gas seal axial gas film stiffness test device based on fine adjustment of closing force according to claim 4 , wherein the auxiliary sealing cavity ( 22 ) is provided with an air inlet hole ( 223 ), A pressure regulating cavity (224) is formed between the auxiliary sealing cavity (22), the stationary ring shaft sleeve (23), the second force sensor seat (35) and the auxiliary positioning ring (222). ) communicates with the pressure regulating chamber (224). 9 . The dry gas seal axial air film stiffness testing device based on closing force fine adjustment according to claim 4 , wherein the auxiliary positioning ring ( 222 ) is radially connected to the second force sensor seat ( 35 ). 10 . A third auxiliary sealing ring (351) is arranged therebetween, and a fourth auxiliary sealing ring (225) is arranged radially between the auxiliary positioning ring (222) and the auxiliary sealing cavity (22). 10 . The dry gas seal axial air film stiffness test device based on fine adjustment of closing force according to claim 1 , wherein the diameter of the first outer peripheral surface ( 333 ) of the first force sensor seat ( 33 ) is 10 . It is equal to the outer diameter of the sealing end face (13) of the sealing static ring (12).

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