A thrust bearing online maintenance device

Abstract

The present invention relates to an online maintenance device for thrust bearings, comprising a sleeve fixedly mounted on the end of a rotor, a hollow nut mounted in the sleeve through a bearing, and an adjusting device arranged at the outer end of the hollow nut for driving the hollow nut to move axially thereof, wherein the hollow nut drives the sleeve to move axially, thereby driving the rotor to move axially thereof. The present invention can realize a one-time inspection of the contact performance of a whole circle of thrust pads, quickly improve the inspection speed and maintenance speed of thrust pads on site, and thus improve the maintenance efficiency of the steam turbine unit. The sleeve is tightly connected to the rotor to form an integrated follower component, and the sleeve and the rotor connected thereto are driven to move axially through the adjusting device, thereby satisfying the fit between the main thrust surface on the thrust bearing and the rotor mating surface, and the fit between the secondary thrust surface and the rotor mating surface, thereby checking whether the contact area of ​​the whole circle meets the assembly design requirements.

Description

Technical Field

[0001] The invention relates to an on-line maintenance device for a thrust bearing. Background Art

[0002] When the steam turbine generator set of a power plant is in operation, the thrust bearing is a vulnerable part and a key component, and it independently bears the thrust in both the positive and negative directions of the rotor axis. Therefore, it is often the case that the thrust bearing has a local pad that fits the rotor mating surface and bears excessive thrust, resulting in increased pad temperature, damage and wear of the pad, and thus endangering the normal operation of the steam turbine. Finally, it is necessary to open the bearing box, disassemble and number the entire circle of thrust pads, grind the pads to match the babbitt alloy surface, and then set up a dial indicator or use a micrometer to check and measure whether the thickness of the entire circle of thrust pads is consistent and within the tolerance range, resulting in a long time for on-site inspection and maintenance. After reinstallation, it is also impossible to ensure that the babbitt alloy surface of the entire circle of thrust pads is in the same plane size, so that when the steam turbine is running again, the temperature of individual pads is still too high. Such repeated disassembly and maintenance operations increase the unnecessary downtime of the unit and waste the operation time of the unit. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an online maintenance device for a thrust bearing, which can realize the online maintenance of the main and auxiliary thrust bearings of the thrust bearing in a steam turbine unit.

[0004] The technical solution adopted by the present invention is: A thrust bearing online maintenance device comprises a sleeve fixedly mounted on the end of a rotor, a hollow nut mounted in the sleeve via a bearing, and an adjusting device arranged at the outer end of the hollow nut for driving the hollow nut to move axially thereof. The hollow nut drives the sleeve to move axially, thereby driving the rotor to move axially thereof.

[0005] Furthermore, the adjustment device includes a baffle bolt, the inner wall of the hollow nut is provided with an internal thread, the baffle nut is screwed and connected with the internal thread through an external thread set in the center, and the outer wall of the outer end of the hollow nut is six-sided.

[0006] Furthermore, the adjustment device also includes a pull rod and an adjustment nut, one end of the pull rod is fixedly connected to the bearing box on the rotor, and the four corners of the baffle bolt are connected to the pull rod and locked and fixed on both sides of the baffle bolt through the adjustment nut.

[0007] Furthermore, a flange surface a is provided at the front end of the rotor, and a flange surface b matching with the flange surface a is provided at the end of the sleeve. The flange surface a and the flange surface b are fixedly connected by a bolt nut assembly, and the bolt nut assembly and the rotor are matched by spherical radial centering.

[0008] Furthermore, a baffle is provided at the other end of the sleeve, and a hole is opened in the middle of the baffle for the hollow nut to pass through. A positioning platform is provided on the outer wall of the hollow nut. There are two bearings that are arranged face to face. The two bearings are respectively located on both sides of the positioning platform. One end of the bearing cooperates with the positioning platform, and the other end cooperates with the corresponding baffle or rotor.

[0009] Furthermore, the bearing is a thrust spherical roller bearing or an angular contact ball bearing.

[0010] Furthermore, the hollow nut is screwed and connected to the baffle bolt through a fine pitch.

[0011] Furthermore, a main thrust surface and an auxiliary thrust surface are provided on the rotor, and a thrust bearing is provided between the main thrust surface and the auxiliary thrust surface. The main thrust bearing and the auxiliary thrust bearing at both ends of the thrust bearing are respectively adapted to the corresponding main thrust surface and the auxiliary thrust surface.

[0012] A maintenance method comprises the following steps: The adjusting device is used to drive the rotor to move left or right along its axial direction. The thrust bearing will produce a relative gap or thrust with the rotor. By applying red lead or blue oil on the entire circle of the main thrust bearing and the entire circle of the auxiliary thrust bearing, the flatness of the Babbitt alloy plane can be achieved by grinding with the main thrust surface or the auxiliary thrust surface of the rotor.

[0013] The positive effects of the present invention are: The present invention has high integration, compact appearance, and simple installation. It is mainly used for online maintenance of the main and auxiliary thrust pads of the thrust bearing in the steam turbine unit, and can realize one-time inspection of the contact performance of the entire circle of thrust pads, quickly improve the on-site thrust pad inspection speed and maintenance speed, and thus improve the maintenance efficiency of the steam turbine unit. The sleeve is tightly connected to the rotor to form an integrated follower component, and the sleeve and the rotor connected thereto are driven to move axially through the adjustment device, thereby satisfying the fit between the main thrust surface on the thrust bearing and the rotor mating surface, and the fit between the auxiliary thrust surface and the rotor mating surface, thereby checking whether the contact area of ​​the entire circle meets the assembly design requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the installation position of the present invention; Figure 2 This is a schematic diagram of the bearing box structure of the present invention; Figure 3 It is a cross-sectional schematic diagram of the online maintenance device of the present invention; Figure 4 It is an overall schematic diagram of the online maintenance device of the present invention; Figure 5 It is a schematic diagram of the main and auxiliary thrust surfaces of the present invention; Figure 6 It is a schematic diagram of the thrust bearing of the present invention; Figure 7It is a schematic diagram of the main thrust bearing of the present invention. DETAILED DESCRIPTION

[0015] The present invention discloses an online maintenance device for thrust bearings, which is mainly used for maintenance work of thrust bearings of steam turbines. When the thrust bearings of steam turbines are under maintenance, personnel are required to dismantle and number the entire circle of main thrust pads and auxiliary thrust pads, and then inspect and repair the babbitt alloy surfaces of the pads individually, and then measure and adjust the effective matching thickness of each pad individually, and finally reinstall them according to the original numbers. However, it cannot be guaranteed that the high points or high surfaces of individual pads are eliminated to the design range value and that the entire circle of thrust pads are in uniform contact with the matching surface of the rotor.

[0016] As attached Figure 1-7 As shown, the thrust bearing of the steam turbine is installed on its rotor 1, and a bearing box 7 is installed at the front end of the rotor 1. A main thrust surface 11 and a secondary thrust surface 12 are provided in the bearing box 7 and on the rotor 1. The thrust bearing 2 is arranged between the main and secondary thrusts. A main thrust bearing 21 and a secondary thrust bearing 22 are provided on both sides of the thrust bearing 2. The main thrust bearing 21 is matched with the main thrust surface 11 of the rotor 1 and is at a designed clearance value, and the secondary thrust bearing 22 is matched with the secondary thrust surface 12 of the rotor 1 and is at a designed clearance value.

[0017] The online maintenance device of the present invention comprises a sleeve 3, a hollow nut 4 and an adjusting device. The sleeve 3 is fixedly mounted on the end of the rotor 1, the hollow nut 4 is sleeved inside the sleeve 3, and a bearing 42 is provided between the hollow nut 4 and the sleeve 3. The adjusting device drives the sleeve 3 to move along the axial direction of the rotor 1, thereby driving the rotor 1 to move axially, satisfying the relative axial movement of the rotor 1 and the relative stillness of the thrust bearing 2 to form a cross-contact surface, thereby performing inspection and maintenance operations.

[0018] Preferably, a flange surface a13 is provided at the front end of the rotor 1, and a flange surface b31 is provided at the right end of the sleeve 3. The flange surface b31 and the flange surface a13 are connected and fastened by a bolt nut assembly 32, thereby realizing the integrated connection between the sleeve 3 and the rotor 1. The bolt nut assembly 32 and the sleeve 3 are matched with a reamed hole 0.02 clearance, and the bolt nut assembly 32 and the rotor 1 are matched with a spherical surface 33 in radial centering, thereby realizing the coaxial arrangement of the sleeve 3 and the rotor 1. Preferably, the number of bolt nut assemblies 32 is 4 sets and they are connected by cross-mounting.

[0019] Two bearings 42 mounted face to face and a hollow nut 4 supporting the bearing 42 are sleeved in the hole of the sleeve 3. A positioning platform 43 is provided on the outer side of the hollow nut 4 and a bearing 42 is provided on each of its left and right sides. A baffle 34 is provided at the left end of the sleeve 3. A hole is opened in the middle of the baffle 34 for the hollow nut 4 to pass through. The baffle 34 is fixed to the sleeve 3 by screws. The bearing 42 at the left end is axially fixed by the baffle 34 and the positioning platform 43, and the bearing 42 at the right end is axially fixed by the flange surface a13 and the positioning platform 43. Therefore, the left and right movement of the hollow nut 4 can drive the bearing 42 and its sleeve 3 and the rotor 1 to move left and right. Preferably, the bearing 42 adopts a thrust spherical roller bearing, which can withstand the axial load of the rotor 1 and the radial load of the sleeve 3, that is, it has good aligning performance. Designers can also choose angular contact ball bearings for installation and positioning according to the working conditions.

[0020] The adjustment device includes a baffle bolt 5, a pull rod 6 and an adjusting nut 8. The hollow nut 4 is provided with an internal thread 41 in the center and a six-sided surface 44 at the left end. The baffle bolt 5 is screwed together with the internal thread 41 through an external thread arranged in the center. Preferably, the thread is a fine thread, and the pitch is preferably ×1 or ×2. The pull rods 6 connected to the front end surface of the bearing box 7 are installed at the four corners of the periphery of the baffle bolt 5 and are locked and fixed on both sides of the baffle bolt 5 through the adjusting nuts 8. By adjusting the relative locking position of the adjusting nuts 8 on both sides of the baffle bolt 5, the relative coarse adjustment distance between the baffle bolt 5 and the bearing box 7 can be achieved. Preferably, 4 pull rods 6 are provided. The hollow nut 4 is screwed together with the baffle bolt 5 through a fine pitch, which has the advantages of small manual screwing torque and fine adjustment of the axial slip of the rotor.

[0021] During maintenance, the six-sided bearing 44 is rotated by a wrench to drive the hollow nut 4 to move leftward or rightward along the axis through the internal and external threads, and then the positioning table 43 presses the left end bearing 42 or the right end bearing 42 and transmits the pressing force to the baffle 34 and the sleeve 3 connected by screws, thereby driving the rotor 1 to move leftward or rightward, and the thrust bearing 2 fixed in the bearing box 7 will generate a relative gap or thrust with the rotor 1. By applying red lead or blue oil to the main thrust bearing 21 and the auxiliary thrust bearing 22, the flatness of the babbitt alloy plane is achieved by grinding with the main thrust surface 11 or the auxiliary thrust surface 12 of the rotor.

[0022] The present invention is installed on-site, with a compact structure and is arranged at the front end of the bearing box 7. The sleeve 3 is directly connected to the rotor 1 to form an integral body. Two sets of thrust spherical roller bearings are arranged face to face on the outer circle of the hollow nut 4 and are connected to the sleeve 3 to withstand both axial thrust and radial centering force. A baffle bolt 5 screwed in through a thread is arranged at the front end of the hollow nut 4, and the baffle bolt 5 is positioned and fixed to the bearing box 7 through surrounding tie rods 6. Finally, when the hollow nut 4 is rotated, it is screwed in or out along the spiral line of its thread, which can drive the bearing and the rotor 1 directly connected to the sleeve 3 to achieve axial movement, thereby satisfying the contact between the main thrust bearing 21 and the auxiliary thrust bearing 22 of the entire circle on both sides of the thrust bearing 2 and the matching surface of the rotor 1. Red lead or blue oil is applied to the main thrust bearing surface and the auxiliary thrust bearing surface. According to the action of the above-mentioned device, it is possible to visually check whether the contact area between the entire circle of bearing blocks and the rotor is qualified, and perform online maintenance on unqualified bearing blocks, effectively improving the efficiency of on-site inspection, shortening the maintenance time, and ensuring one-time qualified maintenance.

[0023] The present invention is installed online to the front end of the turbine rotor 1, and is connected to the rotor 1 and the bearing box 7 to realize a one-time inspection and grinding of the entire circle of the babbitt alloy surface of the main thrust pad and the auxiliary thrust pad of the thrust bearing, thereby improving the one-time qualified rate of the thrust bearing, eliminating the traditional process of disassembling each thrust pad separately, measuring the thickness and grinding, improving the online maintenance efficiency of the thrust bearing, and reducing the downtime of the turbine. At the same time, the present invention is light in weight, modular in design, and simple and fast on-site assembly. The axial sliding of the rotor is realized by the principle of threaded engagement, replacing the backward process of the traditional manual prying of the rotor with a crowbar, which exposes the problems of prying deviation and inability to pry.

[0024] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A thrust bearing online maintenance device, characterized in that It comprises a sleeve (3) fixedly mounted on the end of a rotor (1), a hollow nut (4) mounted in the sleeve (3) via a bearing (42), and an adjusting device arranged at the outer end of the hollow nut (4) for driving the hollow nut (4) to move along its axial direction. The hollow nut (4) drives the sleeve (3) to move along its axial direction, thereby causing the rotor (1) to move along its axial direction.

2. The thrust bearing online maintenance device according to claim 1 is characterized in that The adjustment device comprises a baffle bolt (5), an inner wall of a hollow nut (4) is provided with an internal thread (41), the baffle nut (5) is screwed together with the internal thread (41) via an external thread arranged at the center, and the outer wall of the outer end of the hollow nut (4) is six-sided (44).

3. The thrust bearing online maintenance device according to claim 2 is characterized in that The adjustment device also includes a pull rod (6) and an adjustment nut (8), one end of the pull rod (6) is fixedly connected to the bearing box (7) on the rotor (1), and the four corners of the baffle bolt (5) are connected to the pull rod (6) and locked and fixed on both sides of the baffle bolt (5) through the adjustment nut (8).

4. The thrust bearing online maintenance device according to claim 1 is characterized in that A flange surface a (13) is provided at the front end of the rotor (1), and a flange surface b (31) matching the flange surface a (13) is provided at the end of the sleeve (3). The flange surface a (13) and the flange surface b (31) are fixedly connected via a bolt nut assembly (32), and the bolt nut assembly (32) and the rotor (1) are radially centered via a spherical surface (33).

5. The thrust bearing online maintenance device according to claim 1 or 4, characterized in that A baffle (34) is provided at the other end of the sleeve (3). A hole is opened in the middle of the baffle (34) for the hollow nut (4) to pass through. A positioning platform (43) is provided on the outer wall of the hollow nut (4). Two bearings (42) are arranged face to face. The two bearings (42) are respectively located on both sides of the positioning platform (43). One end of the bearing (42) cooperates with the positioning platform (43), and the other end cooperates with the corresponding baffle (34) or the rotor (1).

6. The thrust bearing online maintenance device according to claim 1, characterized in that The bearing (42) is a thrust spherical roller bearing or an angular contact ball bearing.

7. The thrust bearing online maintenance device according to claim 2 is characterized in that The hollow nut (4) is screwed together with the baffle bolt (5) through a fine pitch thread.

8. The thrust bearing online maintenance device according to claim 1, characterized in that A main thrust surface (11) and a secondary thrust surface (12) are provided on the rotor (1), and a thrust bearing (2) is provided between the main thrust surface and the secondary thrust surface. The main thrust bearing (21) and the secondary thrust bearing (22) at both ends of the thrust bearing (2) are respectively adapted to the corresponding main thrust surface (11) and the secondary thrust surface (12).

9. A maintenance method using the maintenance device according to any one of claims 1 to 8, characterized in that It includes the following steps: By using the adjusting device to drive the rotor (1) to move leftward or rightward along its axial direction, the thrust bearing (2) will generate a relative gap or thrust with the rotor (1). By applying red lead or blue oil to the entire circle of the main thrust bearing (21) and the entire circle of the auxiliary thrust bearing (22), the main thrust surface (11) or the auxiliary thrust surface (12) of the rotor (1) is ground to the flatness of the babbitt alloy plane.

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