A variable characteristic sliding bearing and its application method

Abstract

This invention discloses a variable characteristic sliding bearing and its application method. The invention relates to the fields of steam turbines and gas turbines, specifically to a variable characteristic sliding bearing and its application method, comprising: a bearing bush, a rotor, an upper half of the bearing bush sleeve, and a lower half of the bearing bush sleeve. The bearing bush is installed inside the bearing bush sleeve. The upper and lower halves of the bearing bush sleeve can be connected to form a complete bearing bush sleeve. The upper half of the bearing bush sleeve includes an inner layer and an outer layer. A high-pressure oil groove is provided between the inner and outer layers of the upper half of the bearing bush sleeve. The bearing clearance can be adjusted by changing the oil pressure in the high-pressure oil groove according to the bearing performance requirements of the shaft system. The advantages are: the bearing performance can be adjusted in real time according to the bearing operating conditions and the needs of the supporting unit; a certain performance can be improved as needed; and the adjustment can be performed online. The adjustable bearing characteristics expand the bearing's application space and solve the problems of shaft system vibration or high bearing temperature in the unit.

Description

Technical Field

[0001] This invention relates to the field of steam turbines and gas turbines, and specifically to a variable characteristic sliding bearing and its usage method. Background Technology

[0002] With the increasing size of steam turbines and the growing demand for economic efficiency, the working conditions of rotating machinery bearings are becoming increasingly demanding. Sometimes, it is difficult to balance the stability of bearings and shaft systems with the temperature of bearing bushes.

[0003] When designing bearings, a bearing calculation program based on the principle of hydrodynamic pressure is used to calculate various bearing performances. However, there is an inevitable deviation between the calculated bearing performance and the actual performance. Furthermore, the real-time operating conditions of the bearing usually deviate from the design conditions, so the calculated bearing performance and the actual performance are often inconsistent.

[0004] Theoretically, bearing stability and bearing shell temperature are negatively correlated within a certain range. To maximize the utilization of bearing performance, designing an adjustable sliding bearing, which changes the bearing characteristics according to real-time needs, becomes a good design approach. Summary of the Invention

[0005] The purpose of this invention is to provide a variable characteristic sliding bearing and its usage method, addressing the aforementioned problems.

[0006] The technical solution adopted in this invention is as follows:

[0007] A variable characteristic sliding bearing, comprising:

[0008] The components include a bearing shell, a rotor, an upper half of the bearing shell sleeve, and a lower half of the bearing shell sleeve. The bearing shell is installed on the bearing shell sleeve. The upper and lower halves of the bearing shell sleeve can be connected to form a complete bearing shell sleeve. The upper half of the bearing shell sleeve includes an inner layer and an outer layer. A high-pressure oil groove is provided between the inner and outer layers of the upper half of the bearing shell sleeve. The inner layer of the upper half of the bearing shell sleeve can change the distance between the corresponding bearing shell and the rotor according to the oil pressure in the high-pressure oil groove.

[0009] Furthermore, the upper outer layer of the bearing sleeve is connected to the lower half of the bearing sleeve via a connecting component, and the upper inner layer of the bearing sleeve is connected to the lower half of the bearing sleeve via an elastic component.

[0010] Furthermore, the elastic component includes an elastic element, and the upper inner layer of the bearing sleeve and the lower half of the bearing sleeve are provided with grooves that match the elastic element.

[0011] Furthermore, the elastic element includes a seal. The upper inner layer of the bearing bush is provided with a connecting groove at the corresponding position of the lower half of the bearing bush. The seal is interference-fitted with one side of the connecting groove, and the other side is slidably disposed in the connecting groove.

[0012] Furthermore, the sliding distance of the seal in the connecting groove matches the vertical sliding distance of the upper inner layer of the bearing bush.

[0013] Furthermore, the high-pressure oil tank is connected to a high-pressure oil pump assembly via a high-pressure oil inlet.

[0014] Furthermore, the high-pressure oil pump assembly includes a high-pressure oil pump, a manual shut-off valve, a regulating valve, and a pressure measuring element.

[0015] Furthermore, the control unit, high-pressure oil pump, pressure measuring unit, and regulating valve are all electrically connected to the control unit.

[0016] Furthermore, it includes a locating pin, which is slidably disposed in a locating groove at a corresponding position on the upper inner half of the bearing sleeve and the upper outer half of the bearing sleeve.

[0017] Furthermore, a method of using a variable characteristic sliding bearing includes the following steps:

[0018] S1: When the bearing stability is insufficient, the control unit controls the regulating valve to open and starts the high-pressure oil pump to inject lubricating oil into the high-pressure oil tank;

[0019] S2: After the lubricating oil enters the high-pressure oil tank, the oil pressure in the high-pressure oil tank (6) increases, which transmits pressure to the upper inner layer of the bearing bush, causing the elastic element to contract, and the upper inner layer of the bearing bush drives the upper part of the bearing bush to move towards the bearing split surface.

[0020] S3: Real-time monitoring of the pressure measurements in the pipelines before and after the regulating valve to confirm the working oil pressure and regulating margin in the high-pressure oil tank;

[0021] S4: When the bearing shell operating temperature is high and the shaft system stability is sufficient, close (or partially close) the regulating valve, and the pressure in the high-pressure oil tank drops (to 0 when the regulating valve is fully closed). Under the action of the restoring force of the elastic element and the oil film force between the upper half of the bearing shell and the rotor, the upper inner layer of the bearing shell sleeve moves upward along with the upper half of the bearing shell, and the bearing characteristics change accordingly (the bearing shell temperature decreases, the bearing support stiffness decreases, and the ability to suppress rotor disturbances decreases).

[0022] S5: Observe the oil pressure value returned by the pressure measuring element, and make fine adjustments to restore the upper inner layer of the bearing bush to the optimal position.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] (1) The performance of the bearing can be adjusted in real time according to the bearing operating conditions and the needs of the supporting unit. A certain performance can be improved as needed.

[0025] (2) Simultaneous adjustment can be performed online and is reversible.

[0026] (3) Adjustable bearing characteristics expand the scope of bearing use and help to solve problems such as shaft vibration or high bearing temperature in the unit. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of the bearing of the present invention along line A-A;

[0028] Figure 2 This is a cross-sectional view of the bearing of the present invention along line B-B;

[0029] Figure 3 This is a diagram of the oil supply pipeline of the present invention.

[0030] The markings in the diagram are: 1 - connecting assembly, 2 - bearing shell, 3 - upper inner half of bearing shell sleeve, 4 - upper outer half of bearing shell sleeve, 5 - locating pin, 6 - high-pressure oil groove, 7 - seal, 8 - elastic component, 9 - elastic component, 10 - rotor, 11 - lower half of bearing shell sleeve, 12 - groove, 13 - connecting groove, 14 - high-pressure oil inlet, 15 - high-pressure oil pump assembly, 16 - high-pressure oil pump, 17 - manual shut-off valve, 18 - regulating valve, 19 - pressure measuring element, 20 - locating hole.

[0031] Specific examples

[0032] The present invention will now be described in detail with reference to the accompanying drawings.

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0034] Example 1

[0035] In this embodiment, as Figure 1As shown, the assembly includes: a bearing shell 2, a rotor 10, an upper half of the bearing shell sleeve, and a lower half of the bearing shell sleeve 11. The bearing shell 2 is installed inside the bearing shell sleeve. The upper and lower halves of the bearing shell sleeve can be connected to form a complete bearing shell sleeve. The upper half of the bearing shell sleeve includes an inner layer 3 and an outer layer 4. A high-pressure oil groove 6 is provided between the inner layer 3 and the outer layer 4. The inner layer 3 can change the distance between the corresponding bearing shell 2 and the rotor 10 according to the oil pressure in the high-pressure oil groove 6. In this embodiment, a tilting bearing structure is used. Lubricating oil is continuously introduced into the oil gap between multiple bearing shells 2 and the rotor 10. After the rotor 10 rotates to a certain speed, a complete dynamic pressure oil film is established between the rotor 10 and the bearing shell 2. The rotor 10 is lifted by the oil film and disengages from the bearing shell 2. The oil film provides support stiffness and damping for the rotor 10. Due to factors such as the speed change of the rotor 10, external disturbances, and changes in the temperature of the lubricating oil, the bearing shell 2 can withstand these changes. Rotor 10 may experience instability, so an adjustable bearing sleeve is provided to reduce the bearing clearance when the unit needs to improve bearing stability and appropriately increase the bearing clearance when the oil temperature is too high. Specifically: a bearing sleeve is provided outside the bearing 2. The bearing sleeve is divided into a lower half 11 and an upper half, both with a semi-circular arc design. The two are combined to form a complete bearing sleeve that covers the bearing 2. In order to ensure the stability of the bearing sleeve and the function of adjusting the bearing clearance at the same time, the upper half of the bearing sleeve is divided into an upper inner layer 3 and an upper outer layer 4. A high-pressure oil groove 6 is provided between the upper inner layer 3 and the upper outer layer 4, and the inner side of the upper outer layer 4 matches the outer side of the upper inner layer 3. This design can effectively allow lubricating oil to pass through and distribute the lubricating oil evenly in the high-pressure oil groove 6. When the high-pressure oil enters, the movement stroke of the upper inner layer 3 is controllable.The upper inner layer 3 of the bearing bush can change the distance between the corresponding bearing bush 2 and rotor 10 according to the oil pressure in the high-pressure oil groove 6. When pressure is applied to the lubricating oil in the high-pressure oil groove 6, the upper inner layer 3 of the bearing bush is squeezed downward under the action of oil pressure, causing the bearing bush 2 (upper part) to move downward. The distance A between the upper bearing bush 2 and rotor 10 (the bearing clearance in the installation state) decreases, thereby stabilizing the rotor 10 in an unstable state. In addition, when the bearing is running with a small clearance and the bearing bush temperature is too high, the safety margin of the bearing bush decreases (the bearing bush may melt and burn in severe overheating). At this time, the oil pressure in the high-pressure oil groove 6 can be reduced, so that the upper inner layer 3 of the bearing bush and the upper bearing bush 2 (upper part) are squeezed downward. By moving the upper half of the bearing sleeve (3) upwards, the bearing clearance increases, and the bearing temperature decreases. In this way, a variable-characteristic bearing achieves the technical effect of adjusting bearing characteristics. The advantage of this design is that it utilizes oil pressure to apply pressure from the upper inner layer 3 of the bearing sleeve to the bearing 2, thereby changing the bearing clearance and bearing operating characteristics. This increases the constraint force on the rotor 10 in an unstable operating state, thus restoring it to a stable state. This design uses a simple structure to control the stability of the rotor 10. Furthermore, when the bearing 2 is at a high temperature, it can reduce the oil pressure in the high-pressure oil groove 6, increasing the bearing clearance and allowing more lubricating oil to enter the bearing gap, lubricating and cooling the bearing 2, effectively solving the problem of high temperature in the bearing 2.

[0036] Furthermore, the upper outer layer 4 of the bearing sleeve is connected to the lower half 11 of the bearing sleeve via a connecting component 1, and the upper inner layer 3 of the bearing sleeve is connected to the lower half 11 of the bearing sleeve via an elastic component 8. To maintain the stability of the upper and lower halves of the bearing sleeve and to ensure the anchoring space of the upper inner layer 3, the upper outer layer 4 of the bearing sleeve and the lower half 11 of the bearing sleeve are fixedly connected by bolts. This ensures the integrity of the entire bearing sleeve, which is beneficial to the overall stability of the bearing and the external fixing space. The upper inner layer 3 of the bearing sleeve and the lower half 11 are connected by... The upper inner layer 3 of the bearing sleeve is connected to the lower half 11 of the bearing sleeve via the elastic component 8. Since the upper inner layer 3 of the bearing sleeve needs to move up and down according to the oil pressure change in the high-pressure oil groove 6, in order to maintain the stability of the upper inner layer 3 of the bearing sleeve and its upward or downward reset function, it is connected to the lower half 11 of the bearing sleeve by the elastic component 8. The advantage of this setting is that the movement trajectory of the upper inner layer 3 of the bearing sleeve can be controlled, and elastic force is provided to it when it needs to be reset, so as to ensure the normal operation of the adjustment system.

[0037] Furthermore, the elastic component 8 includes an elastic element 9. The upper inner layer 3 of the bearing sleeve and the lower half 11 of the bearing sleeve are provided with grooves 12 that match the elastic element 9. The elastic element 9 can freely extend and retract within the groove 12. In this embodiment, the elastic element 9 is set as a spring. When installing the spring, the spring is kept at a reset distance that is greater than the range of movement of the upper inner layer 3 of the bearing sleeve, so that it can be fully reset after being compressed, achieving the best effect.

[0038] Furthermore, a connecting groove 13 is provided at the corresponding position of the upper inner layer 3 of the bearing bush and the lower half 11 of the bearing bush. The seal 7 is interference-fitted with the connecting groove 13 on one side of the lower half 11 of the bearing bush and has a small clearance fit with the upper inner layer 3 of the bearing bush. To prevent a large amount of high-pressure oil leakage in the high-pressure oil groove 6, a seal 7 is provided at the connection between the upper inner layer 3 of the bearing bush and the lower half 11 of the bearing bush. In this embodiment, the seal 7 is elongated and has an interference fit on one side with the lower half 11 of the bearing bush, so that it is firmly fixed to the lower half 11 of the bearing bush. A corresponding connecting groove 13 is provided on the inner side of the upper half of the bearing bush, leaving a small gap so that the seal 7 can slide in it. In this way, when the upper inner layer of the bearing bush 2 moves up and down relative to the lower half 11 of the bearing bush, the seal 7 slides in the connecting groove 13 to ensure that it slides in the connecting groove 13. The advantage of this setting is that it blocks the flow of lubricating oil and ensures the pressure in the high-pressure oil groove 6.

[0039] Furthermore, the sliding distance of the seal 7 in the connecting groove 13 is matched with the vertical sliding distance of the upper inner layer 3 of the bearing sleeve. The vertical sliding distance of the seal 7 in the connecting groove 13 is set to be equal to the gap between the upper inner layer of the bearing sleeve and the lower half of the bearing sleeve. In this way, the seal 7 plays a role in limiting the maximum downward movement distance of the upper inner layer of the bearing sleeve, preventing excessive oil pressure in the high-pressure oil groove 6 or excessive reset force of the elastic element 9 from causing excessive displacement, thus ensuring stable operation of the system.

[0040] Furthermore, such as Figure 2 As shown, the high-pressure oil tank 6 is connected to the high-pressure oil pump 16 assembly 15 through the high-pressure oil inlet 14. It adopts an independent oil inlet, which allows the pressure in the high-pressure oil tank 6 to be changed individually, so as to adjust the position of the upper inner layer 3 of the bearing bush sleeve of each bearing individually.

[0041] Furthermore, such as Figure 3As shown, the high-pressure oil pump 16 assembly 15 includes a high-pressure oil pump 16, a manual shut-off valve 17, a regulating valve 18, and a pressure measuring element. The high-pressure oil pump 16 is used to pump high-pressure oil into the high-pressure oil tank 6. The manual shut-off valve 17, the regulating valve 18, and the pressure measuring element are installed on its pipeline. The regulating valve 18 is used to control the oil inlet of the high-pressure oil pump 16, accurately control the oil pressure in the high-pressure oil tank 6, and make the movement distance of the upper inner layer 3 of the bearing bush more accurate. The pressure measuring element is used to provide feedback on the oil pressure in the high-pressure oil tank 6. The operator can visualize the oil pressure in the high-pressure oil tank 6 by reading the pressure display, which makes it easier to understand the system status and make the system operation more stable. When the regulating valve 18 is fully closed, the oil supply of the high-pressure oil pump 16 is cut off.

[0042] Furthermore, the control unit, high-pressure oil pump 16, pressure measuring unit and regulating valve 18 are all electrically connected to the control unit. By electrically connecting the above components to the control unit, the controllable units of the entire system are integrated on the same controller. The advantage of this arrangement is that it enables remote centralized control of the system, and the system stability and operability are higher.

[0043] Furthermore, such as Figure 2 As shown, the system includes a positioning pin 5, which is slidably disposed in the positioning hole 20 corresponding to the upper inner layer 3 and the upper outer layer 4 of the bearing sleeve. The positioning pin 5 is used to determine the left and right position of the upper inner layer 3 of the bearing sleeve and to determine the movement path of the upper inner layer 3 of the bearing sleeve, so as to prevent the upper inner layer 3 of the bearing sleeve from moving unstablely when the oil pressure is increased. At the same time, it limits the maximum upward movement distance of the upper inner layer 3 of the bearing sleeve, preventing the upper inner layer 3 of the bearing sleeve from directly contacting the upper outer layer of the bearing sleeve and causing hard collision damage, so as to make the system operation more stable and reliable.

[0044] Furthermore, a method of using a variable characteristic sliding bearing, applied to a variable characteristic sliding bearing according to any one of claims 1-9, is characterized by comprising the following steps:

[0045] S1: When the bearing stability is insufficient, the control unit controls the regulating valve 18 to open and starts the high-pressure oil pump 16 to inject lubricating oil into the high-pressure oil tank 6.

[0046] S2: After the lubricating oil enters the high-pressure oil tank 6, the oil pressure in the high-pressure oil tank 6 increases, which transmits pressure to the upper inner layer 3 of the bearing bush, causing the elastic element 9 to contract. The upper inner layer 3 of the bearing bush drives the upper part of the bearing bush 2 to move towards the bearing split surface.

[0047] S3: Real-time monitoring of the pressure measurement in the pipelines before and after regulating valve 18 to confirm the working oil pressure and regulation margin in high-pressure oil tank 6;

[0048] S4: When the working temperature of the bearing bush 2 is high and the shaft system stability is sufficient, close (or partially close) the regulating valve 18, and the pressure in the high-pressure oil tank 6 drops (to 0 when the regulating valve is closed). Under the action of the restoring force of the elastic element 9 and the oil film force between the upper bearing bush and the rotor, the upper inner layer 3 of the bearing bush sleeve moves upward along with the upper bearing bush 2, and the bearing characteristics change accordingly (the bearing temperature decreases, the bearing support stiffness decreases, and the ability to suppress rotor disturbances decreases).

[0049] S5: Observe the oil pressure value returned by the pressure measuring element, and make fine adjustments to restore the upper inner layer (3) of the bearing bush to the optimal position.

[0050] Example 2

[0051] Based on Embodiment 1, multiple sets of elastic components 8 are arranged along the bearing axial direction at the connection between the upper half and the lower half 11 of the bearing bush. In this way, the stability of the inner layer 3 of the upper half of the bearing bush can be improved, its overall synchronization can be improved, and the overall system stability can be enhanced.

[0052] The above description is merely a preferred embodiment of the invention and is not intended to limit the invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A variable characteristic sliding bearing, characterized in that: include: The bearing (2), rotor (10), upper half of bearing sleeve and lower half of bearing sleeve (11) are provided. The bearing (2) is installed on the bearing sleeve. The upper half and lower half of the bearing sleeve can be connected and combined to form a complete bearing sleeve. The upper half of the bearing sleeve includes an inner layer (3) and an outer layer (4). A high-pressure oil groove (6) is provided between the inner layer (3) and the outer layer (4). The inner layer (3) of the upper half of the bearing sleeve can change the distance between the corresponding bearing (2) and rotor (10) according to the oil pressure in the high-pressure oil groove (6). The upper outer layer (4) of the bearing sleeve is connected to the lower half (11) of the bearing sleeve by a connecting component (1), and the upper inner layer (3) of the bearing sleeve is connected to the lower half (11) of the bearing sleeve by an elastic component (8). The elastic component (8) includes an elastic element (9), and the upper inner layer (3) of the bearing sleeve and the lower half (11) of the bearing sleeve are provided with grooves (12) that match the elastic element (9) at corresponding positions; The elastic element (9) includes a sealing element (7). The upper inner layer (3) of the bearing sleeve and the lower half (11) of the bearing sleeve are provided with connecting grooves (13). The sealing element (7) is press-fitted with one side of the connecting groove (13), and the other side is slidably disposed in the connecting groove (13). The high-pressure oil tank (6) is connected to a high-pressure oil pump assembly (15) through a high-pressure oil inlet (14); The high-pressure oil pump assembly (15) includes a high-pressure oil pump (16), a manual shut-off valve (17), a regulating valve (18), and a pressure measuring element.

2. A variable characteristic sliding bearing according to claim 1, characterized in that: The sliding distance of the seal (7) in the connecting groove (13) matches the sliding distance of the upper inner layer (3) of the bearing bush.

3. A variable characteristic sliding bearing according to claim 1, characterized in that: The system includes a control unit, and the high-pressure oil pump (16), pressure measuring unit and regulating valve (18) are all electrically connected to the control unit.

4. A variable characteristic sliding bearing according to claim 1, characterized in that: Includes a positioning pin (5), which is slidably disposed in the positioning hole (20) at the corresponding position of the upper inner layer (3) and the upper outer layer (4) of the bearing sleeve.

5. A method of using a variable characteristic sliding bearing, applied to the variable characteristic sliding bearing according to any one of claims 1-4, characterized in that: Includes the following steps: S1: When the bearing stability is insufficient, the control unit controls the regulating valve (18) to open and starts the high-pressure oil pump (16) to inject lubricating oil into the high-pressure oil tank (6); S2: After the lubricating oil enters the high-pressure oil tank (6), the oil pressure in the high-pressure oil tank (6) increases, which transmits pressure to the upper inner layer (3) of the bearing bush, causing the elastic element (9) to contract. The upper inner layer (3) of the bearing bush drives the upper part of the bearing bush (2) to move towards the bearing split surface. S3: Observe the pressure of the pipelines before and after the regulating valve (18) in real time to confirm the working oil pressure and regulating margin in the high-pressure oil tank (6); S4: When the working temperature of the bearing shell (2) is high and the shaft system stability is sufficient, close the regulating valve (18), the pressure in the high pressure oil tank (6) drops, and under the action of the restoring force of the elastic element (9) and the oil film force between the upper half bearing shell and the rotor, the upper half inner layer (3) of the bearing shell sleeve moves upward along with the upper half bearing shell (2), and the bearing characteristics change accordingly. S5: Observe the oil pressure value returned by the pressure measuring element, and make fine adjustments to restore the upper inner layer (3) of the bearing bush to the optimal position.

Images