A self-balancing rotor tilting pump thrust bearing

Abstract

This invention relates to a self-balancing rotor tilting pump thrust bearing, comprising a thrust disc and bearing supports symmetrically arranged on both sides of the thrust disc. The inner surface of the bearing supports has an annular mounting groove, within which upper and lower floating blocks are alternately mounted at intervals. The back of the lower floating block abuts against the bottom of the annular mounting groove, and the front shoulders of the upper and lower floating blocks face each other and serve as mutual force points. A thrust bearing assembly is also fixedly arranged on the bearing support, with one side of the thrust bearing assembly abutting against the back of the upper floating block and the other side abutting against the side surface of the thrust disc. Compared to existing technologies, this invention eliminates the risk of pump rotor damage and seizure caused by the pump thrust disc not being in close contact with the thrust bearings due to various transient condition changes in high-speed pumps.

Description

Technical Field

[0001] This invention belongs to the field of pump bearing technology and relates to a pump thrust bearing with a self-balancing rotor tilting mechanism. Background Technology

[0002] Taking power plant feedwater pumps as an example, feedwater pumps are the core of the power plant's steam-water system, and the safe and stable operation of the pumped medium directly affects the safe operation of the power plant. Power plant feedwater pumps are high-speed rotating pumps, highly sensitive to rotor tilting during operation. Currently, in increasingly common operating conditions, power plant feedwater pumps need to frequently switch operating modes within a very short time to meet the needs of generator unit balanced power generation capacity, peak shaving, and full load operation. During these switching operations, feedwater pumps frequently face adverse effects such as rapid switching between large and small flow rates, turbine load shedding, and water hammer effects in the feedwater pipeline. Under these influences, the high-speed rotating pump rotor experiences unbalanced forces, and the pump's thrust disc cannot fully adhere to the thrust bearing, causing axial or radial deflection of the pump rotor and resulting in pump vibration, which can easily damage high-speed pumps. Summary of the Invention

[0003] The purpose of this invention is to provide a pump thrust bearing with a self-balancing rotor tilting mechanism to eliminate the risk of pump rotor damage and seizure caused by the pump thrust disc not being in close contact with the thrust bearing due to various transient condition switching in high-speed pumps.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A self-balancing rotor tilting pump thrust bearing includes a thrust disc and bearing supports symmetrically arranged on both sides of the thrust disc. The inner surface of the bearing supports has an annular mounting groove. Upper floating blocks and lower floating blocks are alternately installed in the annular mounting groove at intervals. The back of the lower floating block abuts against the bottom of the annular mounting groove, and the front shoulders of the upper and lower floating blocks face each other and serve as force points. A thrust bearing assembly is also fixedly arranged on the bearing support. One side surface of the thrust bearing assembly abuts against the back of the upper floating block, and the other side surface is attached to the side surface of the thrust disc.

[0006] Furthermore, the floating block is fan-shaped in shape, with its upper and lower edges fitting into the annular mounting groove.

[0007] The floating block is also fan-shaped, with its upper and lower edges fitting into the annular mounting groove, and an arc-shaped protrusion on its back.

[0008] Furthermore, the bottom of the annular mounting groove is also provided with a number of first positioning holes that match the number of lower floating blocks at equal intervals. The bottom of the lower floating block is also provided with a second limiting hole that is directly opposite the first positioning hole, and the diameter of the second limiting hole is larger than that of the first positioning hole. An adjustment block positioning pin is also provided at the position where the annular mounting groove abuts against the lower floating block, and one end of the adjustment block positioning pin is interference-fitted with the first positioning hole, and the other end is inserted into the second limiting hole.

[0009] Furthermore, the top of the upper floating block is provided with a first limiting groove extending in the front-to-back direction, and adjustment block positioning screws embedded in the first limiting groove are also installed at intervals on the outer wall of the bearing bracket, and the width of the first limiting groove is greater than the diameter of the adjustment block positioning screw.

[0010] Furthermore, the thrust pad assembly includes a thrust pad body and a thrust pad adjustment block. The front side of the thrust pad body is coated with a layer of Babbitt alloy and contacts the side surface of the thrust disk, while the back side is fixedly installed with the thrust pad adjustment block for resisting the upper floating block.

[0011] Furthermore, the area where the thrust bearing adjustment block contacts the floating block is spherical.

[0012] Furthermore, a first mounting hole is provided on the back of the thrust pad body, and the thrust pad adjustment block is installed in the first mounting hole. Several limiting pins are also evenly distributed around the first mounting hole.

[0013] Furthermore, the bearing bracket is divided into upper and lower parts, with the upper and lower parts split at 45° to the horizontal direction, based on the working state of the pump thrust bearing.

[0014] Furthermore, the outer wall of the bearing bracket is also machined with a first limiting hole at the position of the split surface, and an internal hexagonal flat head screw that extends into the lower floating block closest to the split surface is installed in the first limiting hole.

[0015] Furthermore, the outer wall of the bearing bracket is also provided with several inwardly protruding baffles at intervals, and the thrust pad assembly is embedded between two adjacent baffles.

[0016] Furthermore, a bearing keyway is provided on the top of the outer wall of the bearing bracket, and a bearing key is installed in the bearing keyway by a slotted cylindrical head screw.

[0017] This invention employs the above-described technical solution, where the lower floating block is installed at the bottom of the annular mounting groove and is partially fixed by adjusting the positioning pins of the blocks; the upper floating blocks are arranged face-to-face and staggered above the lower floating blocks, and are also partially fixed by adjusting the positioning screws of the blocks; the back of the lower floating block is curved, the shoulder where the upper and lower floating blocks contact each other is curved, and the surface of the thrust bearing adjusting block is spherical; the positions of the three components are semi-fixed, allowing them to move and tilt within a small range, thereby automatically adjusting their relative positions and angles according to the force conditions. When the pump operates under varying conditions, the load changes, generating thrust in different directions, which is transmitted through the rotor thrust disc to the inner and outer thrust bearing assemblies. The thrust bearings, after balancing and compensating for the force direction through the adjusting blocks, transmit the thrust to the upper floating block, which then transmits the thrust to the two lower floating blocks, causing the lower floating blocks to tilt at a small angle, thus balancing and compensating for the axial displacement. The upper and lower floating block groups and the thrust bearing block group are self-balancing adjusted in this way. By making small adjustments to the relative positions of the components, the axial and radial tilt of the rotor is balanced, so that the rotor and the thrust bearing block are in close contact, and the rotor components will not be damaged or vibrated due to positional deviation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram showing a cross-sectional view of the pump thrust bearing of the present invention;

[0019] Figure 2 This is a schematic diagram from a side view of the pump thrust bearing of the present invention;

[0020] Figure 3 This is a schematic diagram of the bearing support structure;

[0021] Figure 4 This is a schematic diagram of the main view structure of the floating block;

[0022] Figure 5 This is a top view of the floating block;

[0023] Figure 6 This is a schematic diagram of the front view of the floating block;

[0024] Figure 7 This is a top view of the lower floating block;

[0025] Figure 8 This is a schematic diagram of the thrust bearing assembly.

[0026] Figure 9 This is a rear view schematic diagram of the thrust bearing assembly;

[0027] Figure 10 This is a schematic diagram showing the normal operating state of the pump thrust bearing.

[0028] Figure 11This is a schematic diagram showing the state of the pump thrust bearing when it vibrates.

[0029] Explanation of markings in the diagram:

[0030] 1-Bearing bracket; 2-Thrust pad assembly; 3-Upper floating block; 4-Adjusting block positioning screw; 5-Lower floating block; 6-Adjusting block positioning pin; 7-Bearing key; 8-Slotted cylindrical head screw; 9-Hex socket head cap screw; 10-Thrust plate; 11-Annular mounting groove; 12-First positioning hole; 13-Second positioning hole; 14-Bearing keyway; 15-First limiting hole; 16-Second limiting hole; 17-First limiting groove; 18-Thrust pad body; 19-Thrust pad adjusting block; 20-Babbitt alloy; 21-First mounting hole; 22-Baffle. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0032] Unless otherwise specified, the functional components or structures in the following embodiments or examples are conventional components or structures used in the art to achieve the corresponding functions.

[0033] To eliminate the risk of pump rotor damage and seizure caused by the pump thrust disc 10 not being in close contact with the thrust bearing due to various transient condition switching in high-speed pumps, this invention provides a self-balancing rotor tilting pump thrust bearing, the structure of which is described in [reference needed]. Figure 1 and Figure 2 As shown, the device includes a thrust plate 10 and bearing brackets 1 symmetrically arranged on both sides of the thrust plate 10. The inner surface of the bearing bracket 1 is provided with an annular mounting groove 11. Upper floating blocks 3 and lower floating blocks 5 are also alternately installed in the annular mounting groove 11 at intervals. The back of the lower floating block 5 abuts against the bottom of the annular mounting groove 11, and the front shoulders of the upper floating block 3 and the lower floating block 5 face each other and are mutually force-bearing points. A thrust bearing assembly 2 is also fixedly arranged on the bearing bracket 1. One side surface of the thrust bearing assembly 2 abuts against the back of the upper floating block 3, and the other side surface is attached to the side surface of the thrust plate 10.

[0034] For some specific implementation methods, please refer to [link / reference]. Figure 4 and Figure 5 As shown, the floating block 3 is fan-shaped, and its upper and lower edges fit into the annular mounting groove 11.

[0035] For some specific implementation methods, please refer to [link / reference]. Figure 6 and Figure 7As shown, the lower floating block 5 is also fan-shaped, with its upper and lower edges fitting into the annular mounting groove 11, and an arc-shaped protrusion on its back.

[0036] For some specific implementation methods, please refer to [link / reference]. Figure 3 As shown, the bottom of the annular mounting groove 11 is also provided with a plurality of first positioning holes 12 at equal intervals, matching the number of lower floating blocks 5. The bottom of each lower floating block 5 is also provided with a second limiting hole 16 directly opposite the first positioning hole 12, and the diameter of the second limiting hole 16 is larger than that of the first positioning hole 12. An adjusting block positioning pin 6 is also provided at the contact position between the annular mounting groove 11 and the lower floating block 5, with one end of the adjusting block positioning pin 6 interference-fitted with the first positioning hole 12 and the other end inserted into the second limiting hole 16. Preferably, the number of first positioning holes 12 can be six, corresponding to six upper floating blocks 3 and six lower floating blocks 5.

[0037] For some specific implementation methods, please refer to [link / reference]. Figure 4 As shown, the top of the upper floating block 3 is provided with a first limiting groove 17 extending in the front-back direction. Adjusting block positioning screws 4, which are embedded in the first limiting groove 17, are also installed at intervals on the outer wall of the bearing bracket 1. The width of the first limiting groove 17 is greater than the diameter of the adjusting block positioning screws 4.

[0038] For some specific implementation methods, please refer to [link / reference]. Figure 8 and Figure 9 As shown, the thrust pad assembly 2 includes a thrust pad body 18 and a thrust pad adjusting block 19. The front side of the thrust pad body 18 is coated with a layer of Babbitt alloy 20 and contacts the side surface of the thrust disc 10. The back side is fixedly installed with the thrust pad adjusting block 19 to abut against the upper floating block 3. In a more specific embodiment, the area of ​​the thrust pad adjusting block 19 that contacts the upper floating block 3 is spherical. In a more specific embodiment, a first mounting hole 21 is provided on the back side of the thrust pad body 18, and the thrust pad adjusting block 19 is installed in the first mounting hole 21. Several limiting pins are evenly distributed around the first mounting hole 21.

[0039] For some specific implementation methods, please refer to [link / reference]. Figure 3 As shown, the bearing bracket 1 is divided into upper and lower parts, with the split surface of the upper and lower parts at a 45° angle to the horizontal direction, based on the working state of the pump thrust bearing. In a more specific embodiment, the outer wall of the bearing bracket 1 is further machined with a first limiting hole 15 at the position of the split surface, and an internal hexagonal flat head screw 9 extending into the lower floating block 5 closest to the split surface is installed in the first limiting hole 15.

[0040] For some specific implementation methods, please refer to [link / reference]. Figure 3 As shown, the outer wall of the bearing bracket 1 is also provided with a number of inwardly protruding baffles 22 at intervals, and the thrust pad assembly 2 is embedded between two adjacent baffles 22.

[0041] For some specific implementation methods, please refer to [link / reference]. Figure 1 As shown, the top of the outer wall of the bearing bracket 1 is also provided with a bearing keyway 14, and a bearing key is installed in the bearing keyway 14 by a slotted cylindrical head screw 8.

[0042] Each of the above implementation methods can be implemented individually, or in any combination of two or more.

[0043] The above implementation methods will be described in more detail below with reference to specific embodiments.

[0044] Example:

[0045] Reference Figures 1 to 11 As shown, the pump thrust bearing of this embodiment includes a bearing bracket 1, a thrust bearing assembly 2, an upper floating block 3, an adjusting block positioning screw 4, a lower floating block 5, an adjusting block positioning pin 6, a bearing key 7, a slotted cylindrical head screw 8, and an internal hexagonal flat head screw 9. There are two sets of bearing brackets 1, each set consisting of two split sections, with the split face at a 45° angle to the horizontal. This allows the thrust bearing to be assembled with the pump shaft without needing to be fitted from both ends of the shaft. After the bearing housing is installed, the upper and lower parts of the thrust bearing can be directly pushed into the bearing housing. Similarly, when the thrust bearing needs to be disassembled or replaced, only the bearing cover needs to be removed to take out the upper and lower parts of the thrust bearing, thus simplifying the disassembly and assembly process.

[0046] Reference Figure 3 The bearing bracket 1 has an annular mounting groove 11 on its inner side. Six evenly distributed first positioning holes 12 are formed at the bottom of the annular mounting groove 11, and six evenly distributed second positioning holes 13 are formed on the outer edge of the groove. The first positioning holes 12 and the second positioning holes 13 are staggered by 30°. The outer wall of the bearing bracket 1 has six inwardly protruding baffles 22. The top of the bearing bracket 1 has a bearing keyway 14 with a threaded hole at the bottom. The upper and lower parts of the bearing bracket each have a first limiting hole 15, which forms a 15° angle with the split surface and is perpendicular to the axial direction.

[0047] Reference Figure 4 and Figure 5 The floating block 3 is fan-shaped, with its upper and lower edges fitting into the annular mounting groove 11. Both the front and back are flat, and a first limiting groove 17 is provided on the top. The shoulder of the front is an arc surface.

[0048] Reference Figure 6 and Figure 7The lower floating block 5 is fan-shaped, with its upper and lower edges fitting into the annular mounting groove 11. It has an arc-shaped protrusion on the back, with a second limiting hole 16 in the center of the arc. The front is flat, while the shoulder of the front is arc-shaped.

[0049] Reference Figure 8 and Figure 9 The thrust bearing assembly 2 consists of a thrust bearing body 18 and a thrust bearing adjusting block 19. The thrust bearing body 18 is fan-shaped, with its front surface covered by Babbitt alloy 20. The Babbitt alloy 20 has hard phase particles evenly distributed on a soft phase matrix, exhibiting excellent embedding, conformability, and anti-seize properties. After break-in, the soft matrix becomes concave, and the hard particles bulge outward, creating tiny gaps between the sliding surfaces, which serve as oil storage spaces and lubricating oil channels, thus reducing friction. The bulging hard particles also provide support, enhancing load-bearing capacity. A first mounting hole 21 is provided on the back of the thrust bearing body 18. The thrust bearing adjusting block 19 has one spherical side and one flat side, with the flat side facing inward, and is installed in the first mounting hole 21. Perforations 3 are evenly distributed around the first mounting hole 21 to prevent the thrust bearing adjusting block 19 from loosening.

[0050] Reference Figures 1 to 9Six lower floating blocks 5 are mounted face down in the bottom of the annular mounting groove 11. One end of the adjusting block positioning pin 6 is interference-fitted with the first positioning hole 12, and the other end is embedded in the second limiting hole 16. The diameter of the second limiting hole 16 is slightly larger than the diameter of the adjusting block positioning pin 6, thereby limiting the position of the lower floating block 5 and allowing it to deflect within a small range using the back arc protrusion as a fulcrum. Six upper floating blocks 3 are mounted face down in the annular mounting groove 11, arranged face-to-face with the six lower floating blocks 5, so that each upper floating block 3 and each lower floating block 5 contact each other with their shoulder arc surfaces, serving as each other's force points. One end of the adjusting block positioning screw 4 is threaded into the second positioning hole 13, and the other end is embedded in the first limiting groove 17. The width of the first limiting groove 17 is slightly larger than the diameter of the adjusting block positioning screw 4, thereby limiting the position of the upper floating block 3. When the force on the upper floating block 3 changes, it can use the spherical surface of the thrust bearing adjusting block 19 and the shoulder that contacts the lower floating block 5 as fulcrums to perform angular deflection and positional movement within a small range. Six thrust bearing assemblies 2 are arranged on top of the upper floating block 3 with their backs facing down. Each one is embedded between the baffles 22, which serves as a limiting function. The back of the thrust bearing assembly 2, i.e., the spherical surface of the thrust bearing adjusting block 19, rests on the back of the upper floating block 3. The front of the thrust bearing assembly 2 is flat against the side of the thrust plate 10. The bearing key 7 is installed in the bearing keyway 14 through the slotted cylindrical head screw 8. During assembly, it mates with the bearing keyway on the bearing cover, which serves to position the entire thrust bearing. The hex socket head cap screw 9 is installed in the first limiting hole 15 to limit the lower floating block 5, which is installed in the annular mounting groove 11 and is closest to the split surface, to prevent it from falling off. On the other side of the thrust disc 10, as shown in the mirror image above, the whole structure forms a complete pump thrust bearing that can tilt the self-balancing rotor.

[0051] Reference Figure 10 and Figure 11The upper floating block 3 and the lower floating block 5 are arranged regularly and their shoulders are in contact. The back of the upper floating block 3 is in contact with the spherical protrusion of the back of the thrust bearing assembly 2, i.e., the thrust bearing adjusting block 19. The curved surface of the back of the lower floating block 5 is in contact with the bearing bracket 1. The Babbitt alloy on the front of the thrust bearing assembly 2 is in contact with the side of the thrust disc 10. Under normal operating conditions, the axial force is transmitted horizontally, with an angle of 0° with the shaft center, and all components of the thrust bearing are neatly arranged. When the operating conditions change, causing pump vibration, the axial force changes accordingly. At this time, the thrust disc 10 deflects axially, and the force transmission direction forms a certain angle with the shaft center. The thrust disc 10 transmits the thrust to the thrust pad body 18. The thrust pad body 18 transmits the thrust and movement to the upper floating block 3 through the thrust pad support block 19. The upper floating block 3 deflects around the spherical surface of the thrust pad support block 19 and moves downward between the two lower floating blocks 5. The lower floating block 5 is under force and tilts at a certain angle around its back curved surface, using the deflection angle to compensate for the deflection angle and thrust transmitted by the upper floating block 3. The relative positions between the upper floating block 3 and the lower floating block 5, and between the lower floating block 5 and the bearing bracket 1, will automatically correct and compensate according to the thrust direction, so that the front of the thrust pad assembly 2 is always in close contact with the thrust disc 10 under all circumstances. Compensating for rotor tilting under stress using the above methods can ensure that the operation of the thrust bearing remains unaffected, reducing the probability of damage to the thrust disc and thrust bearing pads during switching operating conditions, thereby increasing the service life of the thrust bearing and protecting the safe operation of the pump.

[0052] In general, a thrust bearing is a component used in high-speed rotating pumps to balance the axial force and axial and radial tilt of the pump rotor during high-speed operation. When a high-speed pump encounters varying operating conditions and loads, uneven force on the pump rotor components causes the rotor to tilt in both the radial and axial directions. The self-balancing thrust bearing of this invention can balance both axial and radial tilt and the resulting vibration of the rotor, preventing excessive tilt displacement and vibration from causing wear between the rotor and stationary components, thereby improving pump safety.

[0053] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A pump thrust bearing for self-balancing rotor tilting, characterized in that, The device includes a thrust plate and bearing brackets symmetrically arranged on both sides of the thrust plate. The inner surface of the bearing brackets is provided with an annular mounting groove. Upper floating blocks and lower floating blocks are also alternately installed in the annular mounting groove. The back of the lower floating block abuts against the bottom of the annular mounting groove, and the front shoulders of the upper and lower floating blocks face each other and are mutually force-bearing points. A thrust bearing assembly is also fixedly arranged on the bearing bracket. One side surface of the thrust bearing assembly abuts against the back of the upper floating block, and the other side surface is attached to the side surface of the thrust plate. The thrust pad assembly includes a thrust pad body and a thrust pad adjustment block. The front side of the thrust pad body is coated with a layer of Babbitt alloy and contacts the side surface of the thrust disk, while the back side is fixedly installed with the thrust pad adjustment block for resisting the upper floating block. The bearing bracket is divided into upper and lower parts, with the upper and lower parts split at 45° to the horizontal direction, based on the working state of the pump thrust bearing. The bottom of the annular mounting groove is also provided with a number of first positioning holes that match the number of lower floating blocks at equal intervals. The bottom of the lower floating block is also provided with a second limiting hole that is directly opposite the first positioning hole. The diameter of the second limiting hole is larger than that of the first positioning hole. An adjusting block positioning pin is also provided at the position where the annular mounting groove abuts the lower floating block. One end of the adjusting block positioning pin is interference-fitted with the first positioning hole, and the other end is inserted into the second limiting hole. The top of the upper floating block is provided with a first limiting groove extending in the front-to-back direction. Adjusting block positioning screws embedded in the first limiting groove are also installed at intervals on the outer wall of the bearing bracket. The width of the first limiting groove is greater than the diameter of the adjusting block positioning screw. The lower floating block is installed at the bottom of the annular mounting groove and is partially fixed by adjusting the positioning pin of the block; the upper floating blocks are arranged face-to-face and staggered on top of the lower floating block and are partially fixed by adjusting the positioning screw of the block; the back of the lower floating block is curved, the shoulder where the upper and lower floating blocks contact each other is curved, and the surface of the thrust bearing block adjusting block is spherical; the positions of the three are semi-fixed, allowing them to move and tilt within a small range, thereby automatically adjusting their relative positions and angles according to the force conditions; The area where the thrust bearing adjustment block contacts the floating block is spherical; The back of the thrust pad body is provided with a first mounting hole, and the thrust pad adjustment block is installed in the first mounting hole. Several limiting pins are also evenly distributed around the first mounting hole. The outer wall of the bearing bracket is also machined with a first limiting hole at the position of the split surface, and an internal hexagonal flat head screw that extends into the lower floating block closest to the split surface is also installed in the first limiting hole.

2. The pump thrust bearing for self-balancing rotor tilting according to claim 1, characterized in that, The floating block is fan-shaped, with its upper and lower edges fitting into the annular mounting groove. The floating block is also fan-shaped, with its upper and lower edges fitting into the annular mounting groove, and an arc-shaped protrusion on its back.

3. The pump thrust bearing for self-balancing rotor tilting according to claim 1, characterized in that, The outer wall of the bearing bracket is also provided with several inwardly protruding baffles at intervals, and the thrust pad assembly is embedded between two adjacent baffles.

4. A pump thrust bearing for self-balancing rotor tilting according to claim 1, characterized in that, The bearing bracket has a bearing keyway on the top of its outer wall, and a bearing key is installed in the bearing keyway using a slotted cylindrical head screw.

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