A steam turbine bearing pad center measuring instrument and measuring method

Abstract

The present invention relates to a central measuring instrument for a steam turbine bearing pad, which includes a positioning plate. A vertical long hole is penetrated through the center of the positioning plate. A bearing chamber is inserted into the vertical long hole. The bearing chamber moves up and down in the vertical long hole through an adjusting mechanism arranged at the bottom of the positioning plate. A measuring instrument bearing is installed inside the bearing chamber. A main shaft is rotatably installed inside the measuring instrument bearing. The end of the main shaft penetrates out of the bearing chamber and is connected with a main swing arm. The main swing arm is rotatably connected to the main shaft. The other end of the main swing arm is horizontally connected with a dial indicator bracket. The swing arm assembly rotates circumferentially around the main shaft, and can quickly confirm the installation position of the bearing pad relative to the bearing body at the overhaul site to meet the concentricity requirement.

Description

Technical Field

[0001] The present invention relates to a central measuring instrument and measuring method for steam turbine bearing pads, belonging to the technical field of steam turbine bearings. Background Art

[0002] Steam turbines are important equipment in the fields of thermal power generation and nuclear power generation. The installation conditions of various components of steam turbine bearings have a crucial impact on the stable operation of steam turbines: when installing the bearings, it is necessary to ensure that the arc surfaces of the bearing housing, bearing bracket, bearing pad, and bearing body are concentric with each other to ensure that the position of the steam turbine rotor meets the design standards.

[0003] Currently, the central adjustment of each component of the bearing mainly relies on the combined customization using a large vertical lathe during the manufacturing process by the equipment manufacturer. It is impossible to set up relevant equipment at the overhaul site for precise central measurement. To solve the problem of central measurement and adjustment between the bearing pad and the bearing body at the overhaul site, the present invention designs a central measuring instrument for steam turbine bearing pads. Summary of the Invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a central measuring instrument and measuring method for steam turbine bearing pads, which can quickly confirm the installation position of the bearing pad relative to the bearing body at the overhaul site to meet the concentricity requirements.

[0005] The technical solution of the present invention is as follows:

[0006] A central measuring instrument for steam turbine bearing pads includes a positioning plate. A vertical long hole runs through the center of the positioning plate. A bearing housing is inserted into the vertical long hole. The bearing housing can move up and down in the vertical long hole through an adjusting mechanism arranged at the bottom of the positioning plate. A measuring instrument bearing is installed inside the bearing housing. A main shaft is rotatably installed inside the measuring instrument bearing. The end of the main shaft passes through the bearing housing and is connected to a main swing arm. The main swing arm is rotatably connected to the main shaft. The other end of the main swing arm is horizontally connected to a dial indicator bracket. The swing arm assembly rotates circumferentially around the main shaft.

[0007] Among them, the adjusting mechanism includes a small shaft. The small shaft is rotatably inserted through the bottom center of the positioning plate. A threaded hole running through in the radial direction is provided on the side wall surface of the bearing housing. External threads are provided at the top of the small shaft. The bearing housing and the small shaft are connected through this thread.

[0008] Among them, a handwheel is installed at the bottom end of the small shaft.

[0009] Among them, the bearing housing is installed with a gland through bolts. The bearing housing and the gland clamp the positioning plate between them.

[0010] Among them, the positioning plate is semi-circular, and the outer diameter of the positioning plate is the same as the inner surface of the steam turbine bearing body.

[0011] Among them, several positioning lugs are installed on the side wall of the positioning plate close to the main swing arm, and the other end of the positioning lugs is used to screw the steam turbine bearing body in cooperation with bolts.

[0012] Among them, a lock nut is installed on the small shaft by threading, and the lock nut passes through the positioning plate by threading to lock the small shaft.

[0013] Among them, the dial indicator holder is horizontally arranged towards the positioning plate.

[0014] Among them, shoulders are arranged at both ends in the diameter direction of the positioning plate, and the shoulders are used to support the steam turbine bearing body.

[0015] A method for measuring the center of a steam turbine bearing pad includes the following steps:

[0016] S1: After the steam turbine bearing is installed by the bearing pad and the steam turbine bearing body, embed the positioning plate into the inner surface of the steam turbine bearing body, and make the arc surface of the positioning plate fit the inner surface of the steam turbine bearing body as much as possible.

[0017] S2: When it is confirmed that the positioning plate fits well with the inner surface of the steam turbine bearing body, connect the positioning lugs to between the positioning plate and the steam turbine bearing body by tightening the bolts at both ends of each positioning lug.

[0018] S3: Install a dial indicator in the circular hole reserved at the end of the dial indicator holder, and make the pointer of the dial indicator contact well with the arc surface of the bearing pad.

[0019] S4: After installing the dial indicator, the operator drives the main swing arm to drive the dial indicator holder to rotate along the circumferential direction of the arc surface of the bearing pad. During the rotation process, pay attention to observing the reading of the dial indicator, and judge the deviation of the bearing pad relative to the steam turbine bearing body in the left and right directions by the reading difference of the same angle position in the opposite direction when the dial indicator passes through the arc surface of the bearing pad.

[0020] S5: At this time, remove the bearing pad, increase or decrease the shim of the bearing pad in the left and right directions, install the bearing pad again, and repeat the measurement process until the reading difference of the same angle position in the opposite direction when the dial indicator passes through the arc surface of the bearing pad is 0. At this time, the adjustment of the bearing pad in the left and right directions is completed.

[0021] S6: Rotate the handwheel to drive the small shaft to rotate, and make the bearing housing move up and down in the central long hole of the positioning plate through the threaded connection between the small shaft and the bearing housing until the bearing pad, the steam turbine bearing, and the center measuring instrument of the steam turbine bearing pad are concentric.

[0022] S7: Further observe the difference between the readings of the dial indicator when passing through both ends of the bearing pad and the readings of the dial indicator when passing through the center of the bearing pad to determine the deviation of the bearing pad relative to the steam turbine bearing body in the height direction.

[0023] S8: At this time, remove the bearing pad, add or reduce the gasket of the bearing pad at the bottom, reinstall the bearing pad, and repeat the measurement process until the difference between the readings of the dial indicator when passing through both ends of the bearing pad and the readings of the dial indicator when passing through the center of the bearing pad is 0; then it can be confirmed that the installation position of the bearing pad relative to the steam turbine bearing body meets the concentricity requirements.

[0024] The present invention has the following beneficial effects:

[0025] Through the design of the positioning plate matching the inner circumference of the steam turbine bearing, the center point of the inner circumference of the bearing can be directly determined. Taking the center point of the inner circumference of the bearing as the center of the circle, the swing arm assembly drives the dial indicator to slide along the arc surface of the bearing pad. During the swing process, observing the change in the reading of the dial indicator can analyze the positioning deviation direction and deviation amount when the bearing pad is installed on the bearing body; after determining the installation deviation of the bearing pad, targeted adjustments can be made; then use the present invention to measure the center of the adjusted bearing pad again. When the reading of the dial indicator does not change during the process of swinging the swing arm, it can be directly confirmed that the center of the current bearing pad is concentric with the center of the bearing body; it can quickly and conveniently perform precise center measurement on related equipment at the maintenance site. Description of the Drawings

[0026] Figure 1 It is a cross-sectional view of the present invention;

[0027] Figure 2 It is a rear view of the present invention;

[0028] Figure 3 It is a side view after the installation of the present invention;

[0029] Figure 4 It is a rear view after the installation of the present invention.

[0030] The reference numerals in the drawings are represented as:

[0031] 1, dial indicator stand; 2, main swing arm; 3, positioning hanging ear; 4, positioning plate; 5, gland; 6, bearing chamber; 7, measuring instrument bearing; 8, main shaft; 9, small shaft; 10, lock nut; 11, hand wheel; 12, steam turbine bearing body; 13, bearing pad. Detailed Embodiments

[0032] The present invention will be described in detail below with reference to the drawings and specific embodiments.

[0033] Please refer to Figures 1 to 4 , the invention provides a technical solution:

[0034] A turbine bearing pad center measuring instrument, the device can be made of magnetic material, including a positioning plate 4, the positioning plate 4 is semicircular, and the positioning plate 4 is provided with bosses on both sides of the diameter direction for supporting the turbine bearing, a vertical long hole is passed through the center of the positioning plate 4, a bearing chamber 6 is passed through the vertical long hole, and the bearing chamber 6 is installed at the vertical long hole of the positioning plate 4, so that the axis of the bearing chamber 6 and the semicircular plane of the positioning plate 4 are perpendicular to each other; the bearing chamber 6 moves up and down in the vertical long hole by cooperating with an adjustment mechanism arranged at the bottom of the positioning plate 4, so as to align the bearing pad 13, the turbine bearing, and the turbine through the adjustment mechanism. The three measuring instruments of the center of the bearing pad are concentric; the measuring instrument bearing 7 is installed inside the bearing chamber 6, and the main shaft 8 is rotatably installed inside the measuring instrument bearing 7. The end of the main shaft 8 passes through the bearing chamber 6 and is connected to the main swing arm 2. The main swing arm 2 is rotatably connected to the main shaft 8. The other end of the main swing arm 2 is horizontally connected to the dial indicator frame 1, and the dial indicator frame 1 is horizontally arranged toward the positioning plate 4; the main swing arm 2 rotates in a circumferential direction around the main shaft 8; the dial indicator frame 1 and the main swing arm 2 are L-shaped as a whole, and a circular hole is opened at one end of the main swing arm 2 to match the main shaft 8, and the other end of the main swing arm 2 is connected to the dial indicator frame 1, and the other end of the dial indicator frame 1 has a circular hole for installing a dial indicator.

[0035] The function of the adjusting mechanism is to re-measure the deviation between the bearing pad 13 and the center of the inner surface of the turbine bearing in the height direction after completing the left-right positioning of the bearing pad 13; the adjusting mechanism includes a small shaft 9, which is rotatably penetrated at the bottom of the center of the positioning plate 4, and a through threaded hole is radially opened on the side wall of the bearing chamber 6, and a corresponding external thread is opened on the top of the small shaft 9, and the bearing chamber 6 and the small shaft 9 are connected by the thread; the middle part of the small shaft 9 is connected to the locking cap 10 by a thread, and the tail is fixedly connected to the handwheel 11, and the cylindrical surface of the handwheel 11 is knurled to increase the friction force on the surface of the handwheel 11 for the convenience of the operator. When the locking cap 10 is in a free state, the small shaft 9 is driven to rotate in the circumferential direction by rotating the handwheel 11; therefore, the bearing chamber 6 can be driven to screw back and forth on the small shaft 9 through the small shaft 9, that is, the circumferential rotation of the small shaft 9 is converted into the up and down movement of the bearing chamber 6 in the central long hole of the positioning plate 4 under the action of the threads at the top of the small shaft 9 and the side of the bearing chamber 6.

[0036] As a preferred embodiment, the bearing chamber 6 is installed with a pressure cover 5 by bolts, and the bearing chamber 6 and the pressure cover 5 clamp the positioning plate 4 therebetween; the pressure cover 5 is installed on the other side of the bearing chamber 6 relative to the positioning plate 4, and is fastened with bolts to form a track to guide the bearing chamber 6 to move in the long hole at the center of the positioning plate 4 in the up and down directions, while limiting the movement of the bearing chamber 6 in its circumferential and axial directions.

[0037] The steam turbine bearing is composed of a bearing pad 13 and a steam turbine bearing body 12. The positioning plate 4 is semi-circular, and the outer diameter of the positioning plate 4 is the same as the inner surface of the steam turbine bearing body 12. Moreover, the positioning plate 4 has a certain thickness and can provide sufficient supporting force for the steam turbine bearing. Therefore, when using the measuring instrument, from top to bottom, it is a stacked structure formed by the bearing pad 13, the steam turbine bearing body 12, and the positioning plate 4. The positioning plate 4 supports the steam turbine bearing body 12 through the shoulders on both sides, that is, the top of the shoulders supports the bottom of the steam turbine bearing body 12.

[0038] Four positioning lugs 3 are connected to the semi-circular positioning plate 4 by bolts. The positioning lugs 3 are evenly distributed on the circumferential outer edge of the positioning plate 4. Loosen the bolts so that the positioning lugs 3 can rotate along the circumferential direction relative to the positioning plate 4. The other end of the positioning lug 3 is used in cooperation with bolts to be screwed to the steam turbine bearing body 12. By tightening the bolts, the positioning lugs 3 cannot move relative to the positioning plate 4 at all.

[0039] A method for measuring the center of a steam turbine bearing pad includes the following steps:

[0040] S1: After the steam turbine bearing is installed by the bearing pad 13 and the steam turbine bearing body 12, embed the positioning plate 4 into the inner surface of the steam turbine bearing body 12 and make the arc surface of the positioning plate 4 fit the inner surface of the steam turbine bearing body 12 as much as possible.

[0041] S2: When it is confirmed that the positioning plate 4 fits well with the inner surface of the steam turbine bearing body 12, connect the positioning lugs 3 between the positioning plate 4 and the steam turbine bearing body 12 by tightening the bolts at both ends of each positioning lug 3.

[0042] S3: Install a dial indicator in the round hole reserved at the end of the dial indicator stand 1 so that the pointer of the dial indicator makes good contact with the arc surface of the bearing pad 13.

[0043] S4: After installing the dial indicator, the operator drives the main swing arm 2 to drive the dial indicator stand 1 to rotate along the circumferential direction of the arc surface of the bearing pad 13. During the rotation process, pay attention to observing the reading of the dial indicator, and judge the deviation of the bearing pad 13 relative to the steam turbine bearing body 12 in the left and right directions by the reading difference of the same angle positions in the opposite directions when the dial indicator passes through the arc surface of the bearing pad 13.

[0044] S5: At this time, remove the bearing pad 13, add or subtract the shims of the bearing pad 13 in the left and right directions, install the bearing pad 13 again, and repeat the measurement process until the reading difference of the same angle positions in the opposite directions when the dial indicator passes through the arc surface of the bearing pad 13 is 0. At this time, the adjustment of the bearing pad 13 in the left and right directions is completed.

[0045] S6: Turn the hand wheel 11 to drive the small shaft 9 to rotate, and through the threaded connection between the small shaft 9 and the bearing chamber 6, the bearing chamber 6 moves up and down in the central long hole of the positioning plate 4 until the bearing pad 13, the turbine bearing, and the turbine bearing pad center measuring instrument are aligned and concentric.

[0046] S7: Further observe the difference between the readings of the dial indicator passing through the two ends of the bearing pad 13 and the reading of the dial indicator passing through the center of the bearing pad 13 to determine the deviation of the bearing pad 13 in the height direction relative to the turbine bearing body 12.

[0047] S8: At this time, remove the bearing pad 13, add or reduce the gasket of the bearing pad 13 at the bottom, install the bearing pad 13 again, and repeat the measurement process until the difference between the reading of the dial indicator passing through the two ends of the bearing pad 13 and the reading of the dial indicator passing through the center of the bearing pad 13 is 0; it can be confirmed that the installation position of the bearing pad 13 relative to the turbine bearing body 12 meets the concentricity requirement.

[0048] Steps S1 to S6 complete the alignment in the horizontal and vertical directions, while steps S7 to S8 are mainly used to re-measure whether the height adjustment gasket meets the manufacturer's standards, because the total thickness in the height direction is also affected by other factors.

[0049] The working principle of the above-mentioned turbine bearing pad center measuring instrument and measuring method is as follows:

[0050] After the left and right positioning of the bearing pad 13 is completed, the staff swings the main swing arm 2, observes the changes in the dial indicator reading during the swinging process, and records the dial indicator reading a when the main swing arm 2 passes the left and right center lines of the bearing pad 13. Based on the reading, the height of the main swing arm 2 is raised or lowered by the small shaft 9, so that the change amplitude of the reading during the swinging of the main swing arm 2 is reduced. When the height adjustment of the main swing arm 2 makes the dial indicator reading change very little or even does not change, the dial indicator reading b when the main swing arm 2 passes the left and right center lines of the bearing pad 13 under this condition is recorded, and the adjustment amount of the height direction bearing pad 13 adjustment shim is calculated, that is, the value of ba. According to the requirements of the turbine manufacturer, if the value of ba falls within ±0.3mm, it is considered that the concentricity of the height direction bearing pad 13 meets the standard at this time, otherwise the total thickness of the height direction bearing pad 13 adjustment shim should be readjusted to eliminate the concentricity deviation.

[0051] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A steam turbine bearing pad center measuring instrument, characterized in that: It includes a positioning plate (4) with a vertical long hole penetrating through the center thereof. A bearing housing (6) is inserted into the vertical long hole. The bearing housing (6) moves up and down in the vertical long hole through an adjusting mechanism arranged at the bottom of the positioning plate (4). A measuring instrument bearing (7) is installed inside the bearing housing (6). A main shaft (8) is rotatably installed inside the measuring instrument bearing (7). The end of the main shaft (8) penetrates out of the bearing housing (6) and is connected with a main swing arm (2). The main swing arm (2) is rotatably connected to the main shaft (8). The other end of the main swing arm (2) is horizontally connected with a dial indicator bracket (1). The main swing arm (2) rotates in a circumferential direction around the main shaft (8). The adjusting mechanism includes a small shaft (9). The small shaft (9) is rotatably inserted through the bottom at the center of the positioning plate (4). A threaded hole penetrating through in the radial direction is formed on the side wall surface of the bearing housing (6). External threads are formed at the top of the small shaft (9). The bearing housing (6) and the small shaft (9) are connected through the threads. The bearing housing (6) is installed with a gland (5) through bolts. The bearing housing (6) and the gland (5) clamp the positioning plate (4) therebetween. The measuring method of the center measuring instrument for the steam turbine bearing pad includes the following steps: S1: After the steam turbine bearing is installed by the bearing pad (13) and the steam turbine bearing body (12), the positioning plate (4) is embedded into the inner surface of the steam turbine bearing body (12), and the arc surface of the positioning plate (4) is made to fit the inner surface of the steam turbine bearing body (12) as much as possible. S2: When it is confirmed that the positioning plate (4) fits well with the inner surface of the steam turbine bearing body (12), the positioning lugs (3) are connected between the positioning plate (4) and the steam turbine bearing body (12) by tightening the bolts at both ends of each positioning lug (3). S3: A dial indicator is installed in the round hole reserved at the end of the dial indicator bracket (1) to make the pointer of the dial indicator contact well with the arc surface of the bearing pad (13). S4: After the dial indicator is installed, the operator drives the main swing arm (2) to drive the dial indicator bracket (1) to rotate in the circumferential direction along the arc surface of the bearing pad (13). During the rotation process, pay attention to observing the reading of the dial indicator. The deviation of the bearing pad (13) relative to the steam turbine bearing body (12) in the left - right direction is judged by the reading difference of the dial indicator at the same - angle positions in the opposite directions when the dial indicator passes through the arc surface of the bearing pad (13). S5: At this time, the bearing pad (13) is removed, the shims of the bearing pad (13) are increased or decreased in the left - right direction, and the bearing pad (13) is installed again. The measurement process is repeated until the reading difference of the dial indicator at the same - angle positions in the opposite directions when the dial indicator passes through the arc surface of the bearing pad (13) is 0. At this time, the adjustment of the bearing pad (13) in the left - right direction is completed. S6: Rotate the handwheel (11) to drive the small shaft (9) to rotate. Through the threaded connection between the small shaft (9) and the bearing housing (6), the bearing housing (6) moves up and down in the central long hole of the positioning plate (4) until the bearing pad (13), the steam turbine bearing, and the center measuring instrument of the steam turbine bearing pad are aligned concentrically. S7: Further observe the difference between the readings of the dial indicator passing through both ends of the bearing pad (13) and the reading of the dial indicator passing through the center of the bearing pad (13) to determine the deviation of the bearing pad (13) relative to the steam turbine bearing body (12) in the height direction; S8: At this time, remove the bearing pad (13), add or reduce the shim of the bearing pad (13) at the bottom, reinstall the bearing pad (13), and repeat the measurement process until the difference between the readings of the dial indicator passing through both ends of the bearing pad (13) and the reading of the dial indicator passing through the center of the bearing pad (13) is 0; then it can be confirmed that the installation position of the bearing pad (13) relative to the steam turbine bearing body (12) meets the concentricity requirement.

2. The center measuring instrument for a steam turbine bearing pad according to claim 1, characterized in that: A handwheel (11) is installed at the bottom end of the small shaft (9).

3. The center measuring instrument for steam turbine bearing pads according to claim 2, characterized in that: The positioning plate (4) is semi-circular, and the outer diameter of the positioning plate (4) is the same as the inner surface of the steam turbine bearing body (12).

4. The center measuring instrument for steam turbine bearing pads according to claim 3, characterized in that: A number of positioning lugs (3) are installed on the side wall of the positioning plate (4) close to the main swing arm (2), and the other ends of the positioning lugs (3) are used to screw the steam turbine bearing body (12) in cooperation with bolts.

5. The center measuring instrument for a steam turbine bearing pad according to claim 4, wherein: A lock nut (10) is installed on the small shaft (9) by threading, and the lock nut (10) passes through the positioning plate (4) by threading to lock the small shaft (9).

6. The center measuring instrument for a steam turbine bearing pad according to claim 5, characterized in that: The dial indicator stand (1) is horizontally arranged towards the positioning plate (4).

7. The center measuring instrument for a steam turbine bearing pad according to claim 6, characterized in that: Shoulders are provided at both ends of the positioning plate (4) in the diameter direction, and the shoulders are used to support the steam turbine bearing body (12).

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