A turbine tilting pad support thrust combined bearing

Abstract

The invention discloses a turbine tilting pad support thrust combination bearing, which belongs to the field of bearing design and comprises a support bearing, a thrust bearing and an adjustment plate. The support bearing adopts a tilting pad structure, and the thrust bearing adopts a Kingsbury type improved structure with an oil injection structure. The number of the thrust bearings is two, and the two thrust bearings are respectively arranged at the two ends of the support bearing. The number of the adjustment pads is two, and the two adjustment pads are respectively installed between the support bearing and the thrust bearing. The shaft is a split structure and is provided with an oil inlet structure. The installation structure has good stability and low processing difficulty. The tilting pad can be cooled, the friction power consumption is small, and the vibration is smooth. The bearing is very suitable for use in high-speed running equipment such as a turbine.

Description

Technical Field

[0001] The invention relates to a turbine tilting pad support thrust combined bearing, in particular to the technical field of bearing design. Background Art

[0002] In the modern production and assembly process, the tilting pad radial bearing is often the preferred bearing for the high-speed rotor of the steam turbine. The tilting pad radial bearing is the most stable bearing form. It is usually composed of multiple tilting pads cast with babbitt alloy. The tilting pads can automatically adjust the pad inclination with the change of load and speed, forming multiple oil wedges and dynamic oil films. The back of each pad is in line contact with the bearing body. The oil film gap can be adjusted dynamically during operation. Therefore, the tilting pad bearing has good vibration reduction performance. It is mainly used in high-speed and light-load equipment such as steam turbines, compressors, turbine equipment, and pumps. The tilting pad bearing has increased support flexibility and has the ability to absorb vibration because the pads can swing freely, that is, it has good shock absorption. The high and medium pressure rotors of steam turbines are light and prone to steam vortex. The use of tilting pads has better stability. Due to the high-speed working condition characteristics of the tilting pad bearing, the tilting pad radial thrust bearing has excellent vibration resistance and high-speed stability performance, which can meet the radial and thrust load conditions under high speed.

[0003] The existing butterfly spring supported tilting pad thrust bearing includes a thrust plate, a thrust pad, a support block, a cushion block, a butterfly spring, a collar and a locking bolt. The thrust pad and the support block form a thrust pad. The butterfly spring is mounted on the collar, the cushion block is mounted on the upper part of the butterfly spring and is fastened by the locking bolt, and the thrust pad is mounted on the cushion block. The bearing specifically adjusts the height difference between the pads through the elasticity of the butterfly spring so that each pad can contact the thrust plate, and the center point support can play a self-balancing role. The combination of the two phases further improves the reliability and performance of the thrust bearing. The bearing can automatically adjust the problem of uneven height between the pads caused by manufacturing and assembly errors between the tilting pad sliding thrust bearings, thereby improving the reliability, maintainability and stability of the thrust bearing.

[0004] The bearing has the following disadvantages:

[0005] First, the butterfly spring used in the fixed bearing cannot meet the high-speed rotation conditions, and the spring is easily deformed, which reduces the use effect.

[0006] Second, the tilting pad radial thrust bearing cannot achieve the adaptive centering performance of the radial pad and is sensitive to the misalignment and runout of the rotor, which can easily cause the bearing temperature to rise, the friction power consumption to be large, and the vibration to be abnormal.

[0007] Third, there is only a thrust shaft but no radial support shaft. The single thrust bearing cannot stably fit the rotor, causing severe vibration of the bearing during operation.

[0008] Fourth, there is no oil inlet device, lack of lubricating oil, and failure to form a high-pressure oil film. During the rotation of the rotor, the bearing parts are prone to overheating, the parts are severely worn, and the tilting pads collide severely.

[0009] Fifth, the installation structure has poor stability, and it is easy for the bearing shell or tilting pad to rotate with the rotor during use. Summary of the invention

[0010] The object of the present invention is to provide a turbine tilting pad support thrust combination bearing to solve the technical problems of poor stability, severe wear and easy rotation of the bearing itself in the prior art.

[0011] The present invention provides a turbine tilting pad support thrust combination bearing, comprising a support bearing, a thrust bearing and an adjustment pad. The support bearing adopts a tilting pad structure, and the thrust bearing adopts an improved Kingsbury structure with an oil injection structure. There are two thrust bearings, which are respectively arranged at both ends of the support bearing. There are two adjustment pads, which are respectively installed between the support bearing and the thrust bearing.

[0012] Further, the support bearing includes a support bearing body, a radial tilting pad, a radial bearing end cover, a radial pad end face limit screw, a radial pad back limit screw, a radial oil nozzle, a support bearing body fastening screw, a support bearing body positioning pin, and a support bearing anti-rotation pin. The radial tilting pad is installed in the support bearing body. There are two radial bearing end covers, and the radial bearing end covers are respectively fixed at both ends of the support bearing body through the radial pad end face limit screws. The radial pad back limit screws penetrate the side wall of the support bearing body and abut against the radial tilting pad. The radial oil nozzle penetrates the side wall of the support bearing body and opens inward. The radial oil nozzle is supplied with oil from the outside. The support bearing body fastening screws and the support bearing body positioning pins are installed in the side wall of the support bearing body. The support bearing body is positioned and fastened by the support bearing body fastening screws and the support bearing body positioning pin combination, and the support bearing anti-rotation pin is inserted in the middle position of the outer side wall of the support bearing body.

[0013] Further, the thrust bearing includes a thrust pad, a thrust pad supporting ball head, a thrust pad oil inlet joint, an upper balancing block, an upper balancing block limit screw, a lower balancing block, a lower balancing block limit pin, a thrust bearing seat, an adjustment pad, a thrust bearing anti-rotation block, and an anti-rotation block fastening screw. There are two thrust bearing seats and they are respectively installed on the outsides of the two adjustment pads. Several lower balancing blocks are respectively installed on the thrust bearing seats. The lower balancing block limit pin is plugged and installed between the thrust bearing seat and the lower balancing block. The two ends of the upper balancing block are respectively covered on the two lower balancing blocks. The upper balancing block limit screw passes through the side wall of the thrust bearing seat and fixes the upper balancing block.

[0014] Furthermore, several of the thrust pads are installed on several of the upper balancing blocks, the thrust pad oil inlet joint is installed in the side wall of the thrust pad, the thrust pad oil inlet joint passes through the side walls at both ends of the thrust pad and the outer end of the thrust bearing seat, the thrust pad support ball head is installed on the upper balancing block, the thrust pad back and the thrust pad support ball head are in point contact, the thrust pad is supported on the bridge structure formed by the outer side of the upper balancing block, the thrust bearing anti-rotation block is installed on the outer side wall of the thrust bearing seat, and the anti-rotation block fastening screw is installed on the outer wall of the thrust bearing anti-rotation block.

[0015] Furthermore, the supporting bearing body and the thrust bearing seat are split structures.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] Firstly, the existing bearings are supported by butterfly springs, which have poor stability and the springs are easily deformed. The adaptive centering performance of the radial pads cannot be achieved and the bearings are sensitive to the misalignment and skew of the rotor, which easily causes the bearing temperature to rise, the friction power consumption to be large, and the vibration to be abnormal. The thickness of the bearing alloy of the tilting pad of this bearing is as thin as 0.2-0.4mm, which improves the fatigue resistance of the pads. The structure overcomes the function of combined compensation of radial and thrust forces. The thrust pad relies on the supporting ball head, and the supporting bearing body inner wall and radial pad rely on the radial pad back limit screws, which can realize point contact free adjustment, and the pads can be adjusted in all directions to compensate for the misalignment and skew of the rotor.

[0018] Secondly, the existing combined bearings are integrally formed, difficult to install and difficult to process, while the present bearing adopts a split structure of the support bearing and the thrust bearing, and relies on the independent adaptive self-aligning function of the support and thrust bearings to greatly reduce the difficulty of processing.

[0019] Third, the existing bearing linkage structure relies on fixings, has no buffer space, and has no lubricating oil inlet structure, which easily causes excessive temperature of parts, large friction power consumption, and vibration. The thrust bearing of this bearing adopts a bridge linkage structure, which can better equalize the load, compensate for rotor deflection, and improve the high-speed stability performance of the bearing. The radial bearing and the thrust bearing are equipped with oil spray nozzles. The direct oil injection lubrication method can reduce the mixing of hot oil during use and reduce the state of oil mixing. The cold oil directly enters the lubrication surface, greatly reducing the lubrication temperature rise of the oil film, reducing power consumption, and improving lubrication performance.

[0020] Fourthly, the existing bearings do not limit the bearings themselves, which may easily cause the bearings themselves to rotate or misalign with the rotor. However, the positioning pins of the support bearing body of the bearing limit the outer shell assembly, the thrust bearing anti-rotation block prevents the thrust bearing seat from rotating, the support bearing anti-rotation pin prevents the support bearing body from rotating, and the lower balance block limit pin prevents the lower balance block from sliding, which greatly increases the structural stability of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is an engineering drawing view of the present invention;

[0023] Figure 2 for Figure 1 Section view along line AA;

[0024] Figure 3 for Figure 1 Sectional view along line BB;

[0025] Figure 4 It is a front view of the present invention;

[0026] Figure 5 for Figure 4 Sectional view along line CC;

[0027] Figure 6 for Figure 4 Sectional view along line DD;

[0028] Figure 7 for Figure 1 Partial cross-sectional view along line EE.

[0029] Figure markings: support bearing body 1, radial tilting pad 2, radial bearing end cover 3, radial pad end face limit screw 4, radial pad back limit screw 5, radial oil injector 6, support bearing body fastening screw 7, support bearing body positioning pin 8, support bearing anti-rotation pin 18, thrust pad 9, thrust pad support ball head 10, thrust pad oil inlet joint 11, upper balancing block 12, upper balancing block limit screw 13, lower balancing block 14, lower balancing block limit pin 15, thrust bearing seat 16, adjustment pad 17, thrust bearing anti-rotation block 19, anti-rotation block fastening screw 20, support bearing 21, thrust bearing 22. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0031] The components of the embodiments of the present invention generally described and shown in the drawings herein may be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0032] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Combine the following Figures 1 to 7As shown, an embodiment of the present invention provides a turbine tilting pad support thrust combination bearing, including a support bearing 21, a thrust bearing 22 and an adjustment pad 17. The support bearing 21 adopts a tilting pad structure, and the thrust bearing 22 adopts a Kingsbury type improved structure with an oil injection structure. There are two thrust bearings 22, and the two thrust bearings 22 are respectively arranged at both ends of the support bearing 21. There are two adjusting pads 17, and the two adjusting pads 17 are respectively installed between the support bearing 21 and the thrust bearing 22, thus forming a complete bearing assembly.

[0036] The support bearing 21 includes a support bearing body 1, a radial tilting pad 2, a radial bearing end cover 3, a radial pad end face limit screw 4, a radial pad back limit screw 5, a radial oil nozzle 6, a support bearing body fastening screw 7, a support bearing body positioning pin 8 and a support bearing anti-rotation pin 18. The radial tilting pad 2 is installed in the support bearing body 1. There are two radial bearing end covers 3, which are respectively fixed at both ends of the support bearing body 1 through the radial pad end face limit screw 4. The radial pad back limit screw 5 passes through the side wall of the support bearing body 1 and contacts the radial tilting pad 2, which can become a fulcrum, so that there is a certain distance between the back of the radial pad and the inner wall of the support bearing body 1. Since the cross-section of the inner wall of the support bearing body 1 is arc-shaped, it forms a point contact with the radial pad, which can also prevent severe friction and collision and extend the service life. The radial oil nozzle 6 passes through the support bearing body 1 The radial tilting pad 2 is limited by radial oil nozzles 6 on both sides and a combination of limit screws on the pad back, and the radial oil nozzles 6 are supplied with oil from the outside. The support bearing body fastening screws 7 and the support bearing body locating pins 8 are installed in the side walls of the support bearing body 1. The support bearing body 1 is positioned and fastened by the support bearing body fastening screws 7 and the support bearing body locating pins 8. The support bearing anti-rotation pin 18 is inserted in the middle position of the outer side wall of the support bearing body 1, so as to prevent the support bearing body 1 from rotating with the rotor during use.

[0037] The thrust bearing 22 includes a thrust pad 9, a thrust pad support ball head 10, a thrust pad oil inlet joint 11, an upper balancing block 12, an upper balancing block limit screw 13, a lower balancing block 14, a lower balancing block limit pin 15, a thrust bearing seat 16, a thrust bearing anti-rotation block 19 and an anti-rotation block fastening screw 20. The thrust bearing seats 16 are two in number and are respectively installed on the outer sides of the two adjustment pads 17. Several lower balancing blocks 14 are respectively installed on the thrust bearing seats 16. The lower balancing block limit pin 15 is plugged and installed on the thrust bearing The upper balancing block 12 is provided between the seat 16 and the lower balancing block 14, so that the lower balancing block 14 can be limited to prevent it from being displaced with the rotation of the rotor during rotation. The two ends of the upper balancing block 12 are respectively covered on the two lower balancing blocks 14, so that the lower balancing block 14 can be clamped to prevent it from loosening and falling off. The upper balancing block limit screw 13 passes through the side wall of the thrust bearing seat 16 and fixes the upper balancing block 12. The upper balancing block 12 and the lower balancing block 14 are combined to form a bridge-type lap structure, which can be adaptively adjusted according to the working conditions to achieve local limitation and prevent loosening and displacement.

[0038] A number of the thrust pads 9 are installed on a number of the upper balancing blocks 12, the thrust pad oil inlet joint 11 is installed in the side wall of the thrust pad 9, the thrust pad oil inlet joint 11 passes through the side walls of the thrust pad 9 at both ends and the outer end of the thrust bearing seat 16, the thrust pad support ball head 10 is installed on the upper balancing block 12, the back of the thrust pad 9 and the thrust pad support ball head 10 are in point contact, the thrust pad 9 is supported on the bridge structure formed by the outer side of the upper balancing block 12, the thrust bearing anti-rotation block 19 is installed on the outer wall of the thrust bearing seat 16, and the anti-rotation block fastening screw 20 is installed on the outer wall of the thrust bearing anti-rotation block 19, so that the thrust bearing seat 16 can be prevented from rotating with the rotor during operation by limiting the thrust bearing anti-rotation block 19 from the outside. In actual use, the radial tilting pad 2 The thrust pad 9 is adaptively adjusted according to the rotational speed, load and unit processing and assembly errors, so that the load distribution is more uniform, the adjustment is flexible, and the misalignment and deflection of the rotor can be compensated.

[0039] The thickness of the tilting pad bearing alloy is as thin as 0.2-0.4mm, which improves the fatigue resistance of the pad. The radial side of the bearing is a tilting pad structure, and both the positive and negative thrust ends adopt a tilting thrust pad structure. In this way, the support bearing and the thrust bearing 22 are split structures, relying on the independent adaptive self-aligning function of the support and thrust bearing 22, which greatly reduces the difficulty of processing.

[0040] Working principle: During operation, the rotor rotates in the bearing group, and the support bearing body 1 and the radial bearing end cover 3 form a sealing area. The interior is filled with lubricating oil through the radial oil nozzle 6 under the oil supply pressure of the oil supply system, and the lubricating oil is brought between the inner wall of the support bearing body 1 and the back of the radial tilting pad 2. The radial tilting pad 2 starts to swing freely by relying on the radial pad back limit screw 5 as a point support, and oil is supplied between the thrust pad 9 and the thrust bearing seat 16 through the thrust pad oil inlet joint 11. The thrust pad 9 starts to swing freely by relying on the thrust pad support ball head 10 as a point support, and then the radial tilting pad 2 and the thrust pad 9 are adaptively adjusted according to the speed and load as well as the processing and assembly errors of the unit to meet the working conditions, thereby forming a dynamic pressure oil film to support the rotating rotor.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A turbine tilting pad support thrust combined bearing, characterized in that: It comprises a support bearing (21), a thrust bearing (22) and an adjustment pad (17), wherein the support bearing (21) adopts a tilting pad structure, and the thrust bearing (22) adopts a Kingsbury-type improved structure with an oil injection structure, wherein there are two thrust bearings (22), and the two thrust bearings (22) are respectively arranged at two ends of the support bearing (21), and there are two adjustment pads (17), and the two adjustment pads (17) are respectively installed between the support bearing (21) and the thrust bearing (22); The support bearing (21) comprises a support bearing body (1), a radial tilting pad (2), a radial bearing end cover (3), a radial pad end face limit screw (4), a radial pad back limit screw (5), a radial oil nozzle (6), a support bearing body fastening screw (7), a support bearing body positioning pin (8), and a support bearing anti-rotation pin (18). The radial tilting pad (2) is installed in the support bearing body (1). The number of the radial bearing end covers (3) is two. The radial bearing end covers (3) are respectively fixedly arranged at both ends of the support bearing body (1) by the radial pad end face limit screw (4). The radial pad back limit screw (5) passes through the side wall of the support bearing body (1) and contacts the radial tilting pad (2); the radial oil injection nozzle (6) passes through the side wall of the support bearing body (1) and opens inward; the radial oil injection nozzle (6) is supplied with oil from the outside; the support bearing body fastening screw (7) and the support bearing body positioning pin (8) are installed in the side wall of the support bearing body (1); the support bearing body (1) is positioned and fastened by the support bearing body fastening screw (7) and the support bearing body positioning pin (8); the support bearing anti-rotation pin (18) is inserted in the middle position of the outer side wall of the support bearing body (1); The thrust bearing (22) comprises a thrust pad (9), a thrust pad supporting ball head (10), a thrust pad oil inlet joint (11), an upper balancing block (12), an upper balancing block limit screw (13), a lower balancing block (14), a lower balancing block limit pin (15), a thrust bearing seat (16), an adjustment pad (17), a thrust bearing anti-rotation block (19), and an anti-rotation block fastening screw (20). The thrust bearing seats (16) are two in number and are respectively mounted on the two adjusting plates. On the outer side of the whole pad (17), a plurality of lower balancing blocks (14) are respectively mounted on the thrust bearing seat (16), the lower balancing block stop pin (15) is plugged and mounted between the thrust bearing seat (16) and the lower balancing block (14), the two ends of the upper balancing block (12) are respectively covered on the two lower balancing blocks (14), and the upper balancing block stop screw (13) penetrates the side wall of the thrust bearing seat (16) and fixes the upper balancing block (12); A plurality of the thrust pads (9) are mounted on a plurality of the upper balancing blocks (12); the thrust pad oil inlet joint (11) is mounted in the side wall of the thrust pad (9); the thrust pad oil inlet joint (11) penetrates the side walls at both ends of the thrust pad (9) and the outer end of the thrust bearing seat (16); the thrust pad support ball head (10) is mounted on the upper balancing block (12); the back of the thrust pad (9) and the thrust pad support ball head (10) are in point contact; the thrust pad (9) is supported on the outer side of the upper balancing block (12) to form a bridge structure; the thrust bearing anti-rotation block (19) is mounted on the outer side wall of the thrust bearing seat (16); and the anti-rotation block fastening screw (20) is mounted on the outer side wall of the thrust bearing anti-rotation block (19); The support bearing body (1) and the thrust bearing seat (16) are split structures.

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