A connecting structure and method for a steam turbine cylinder and a bearing housing

Abstract

A connecting structure and connecting method for a steam turbine cylinder and bearing box belong to the technical field of steam turbines. In the process of thermal expansion and contraction of the unit, how to ensure good centering, reduce the absolute expansion amount of the front bearing box body or realize independent positioning, and avoid the safety hazards of the unit caused by uneven expansion or jamming. The present application comprises a lower half claw of the cylinder, a radial positioning mechanism and a claw positioning mechanism. The lower half claw of the cylinder is lapped on the supporting surface of the bearing box body. The claw positioning mechanism is arranged between the lower half claw of the cylinder and the bearing box body, and is used for limiting the lower half claw of the cylinder in the horizontal and vertical directions. The radial positioning mechanism is installed between the steam turbine cylinder and the bearing box body, and is used for realizing the radial positioning between the steam turbine and the bearing box body. The connecting structure of the present application adopts the fixed bearing box body. The lower half claw of the cylinder is directly lapped on the bearing box body and slides along the axial direction of the bearing box body. When the cylinder is heated and expanded, the bearing box body is no longer moved.

Description

Technical Field

[0001] This invention belongs to the field of steam turbine technology, and particularly relates to a connection structure and connection method for a steam turbine cylinder and bearing housing. Background Technology

[0002] With my country's goals of achieving carbon peaking and carbon neutrality, the pace of clean and low-carbon transformation of the power system will accelerate further. Coal-fired power will gradually shift from being the primary source of electricity to a supporting and regulating power source that balances electricity generation and output. To promote the rapid development of renewable energy, thermal power plants have been exploring ways to improve their operational flexibility. Flexible operation includes two aspects: firstly, a rapid load change rate; and secondly, safe and reliable start-up, shutdown, and peak-shaving capabilities. It is understood that in some regions of China, due to the large installed capacity of renewable energy generation, there are often markets with zero or negative electricity prices. As a result, units have to be put into hot standby or shut down, and then quickly start up and connect to the grid or quickly introduce steam to meet the demand when peak load is needed. For some units with older designs or outdated sliding pin systems (prone to excessive expansion or jamming), or newly built units, it is necessary to optimize their sliding pin systems to ensure that the units are not affected by expansion and contraction and thus cannot meet the requirements of grid-side load changes.

[0003] Taking the cat claw support high-pressure cylinder module as an example, in the original design, the cylinder and the front bearing housing are connected by a fixed center beam and a cat claw push-pull structure. During thermal expansion, the cylinder expands from the unit dead point (usually the center line of the low-pressure cylinder or the adjacent fixed bearing housing) towards the free end. Due to the expansion transmission of the high and medium pressure cylinders and the intermediate bearing housing, some units will experience an absolute expansion of nearly 20-40mm at the front bearing housing. Some older units, due to the lack of cleaning of the lower base frame of the front bearing housing for a long time, will also cause uneven expansion on the left and right sides of the unit, resulting in tilting and affecting the safety of the unit.

[0004] Taking the intermediate pressure cylinder module of a 1000 MW or 660 MW double reheat unit as an example, if the adjacent bearing box of the No. 1 low-pressure cylinder is taken as the dead point and connected in the manner of fixed center beam and cat claw push-pull structure, the entire ultra-high pressure cylinder will push the front bearing box forward to expand by about 60 mm. Therefore, it is necessary to optimize the connection structure between the intermediate pressure cylinder module and the adjacent bearing box.

[0005] Therefore, there is an urgent need for a sliding pin system connection structure suitable for the flexible operation requirements of high-parameter, large-capacity thermal power units. This structure should ensure good alignment during the thermal expansion and contraction of the unit, reduce the absolute expansion of the front bearing housing or achieve its independent positioning, avoid safety hazards caused by uneven expansion or jamming, and adapt to the operational requirements of rapid start-up and shutdown, deep peak shaving and rapid load change of the unit. Summary of the Invention

[0006] In view of this, the present invention provides a connection structure and method for connecting a turbine cylinder and a bearing housing. The lower half of the cylinder, resembling a cat's claw, directly overlaps the bearing housing and slides axially along the bearing housing. When the cylinder expands due to heat, it no longer pushes the bearing housing to move. Compared with the traditional fixed-center beam and cat's claw push-pull structure, the front bearing housing no longer bears the 20-60mm absolute expansion transmitted from the high-pressure cylinder, effectively avoiding problems such as bearing housing jamming, uneven expansion on the left and right sides, and skewing caused by excessive expansion.

[0007] The technical solution adopted in this invention is as follows:

[0008] A connection structure for a steam turbine cylinder and a bearing housing includes a lower half of the cylinder claw, a radial positioning mechanism, and a claw positioning mechanism. The lower half of the cylinder claw overlaps the support surface of the bearing housing. The claw positioning mechanism is disposed between the lower half of the cylinder claw and the bearing housing for lateral and vertical limiting of the lower half of the cylinder claw. The radial positioning mechanism is installed between the lower half of the steam turbine cylinder and the bearing housing for radial positioning between the steam turbine cylinder and the bearing housing.

[0009] The radial positioning mechanism includes a radial positioning block and a central positioning block. Two radial positioning blocks are provided and are fixedly installed side by side on the lower half end face of the cylinder in the radial direction, forming a radial positioning groove between the two radial positioning blocks. One end of the central positioning block is fixedly connected to the bearing housing, and the other end is inserted into the radial positioning groove in the axial direction, so that the lower half end face of the cylinder and the bearing housing are radially positioned through the cooperation of the radial positioning block and the central positioning block.

[0010] Furthermore, an L-shaped gasket is provided on each side of the central positioning block. The L-shaped gasket is fastened to the edge of the central positioning block, and its horizontal section abuts against the upper surface of the central positioning block and is fixedly installed on the central positioning block. The vertical section of the L-shaped gasket is located in the gap between the radial positioning block and the central positioning block, and there is a clearance fit between it and the radial positioning block.

[0011] Furthermore, the cat paw positioning mechanism includes an L-shaped guide block and a limiting block. A positioning step is provided on the side end face of the lower half of the cylinder cat paw. The vertical section of the L-shaped guide block is fixedly installed on the upper surface of the bearing housing. The horizontal section of the L-shaped guide block extends to the top of the cat paw positioning step. The limiting block is fixedly installed on the lower end face of the horizontal section of the L-shaped guide block and is positioned towards the cat paw positioning step. A vertical assembly gap is reserved between the lower end face of the limiting block and the upper end face of the cat paw positioning step.

[0012] Furthermore, a lateral gap is left between the side of the vertical section of the L-shaped guide block near the lower half of the cylinder's claw and the side end face of the claw.

[0013] Furthermore, it also includes sliding pads, of which two are provided and are arranged opposite each other between the lower half of the cylinder claw and the bearing housing. The two sliding pads are in contact with each other to form a pair of friction pairs that can slide relative to each other along the axial direction.

[0014] Furthermore, it also includes a clamping mechanism, which is installed on the side end face of the lower half of the cylinder claw and the upper surface of the bearing housing. Each sliding pad has a limiting clamping block at the end facing the clamping mechanism. The two limiting clamping blocks fit tightly together and together form a limiting structure clamped by the clamping mechanism.

[0015] Furthermore, the clamping mechanism includes an upper clamping block and a lower clamping block. The upper clamping block is fixedly installed on the side end face of the lower half of the cylinder claw, and the lower clamping block is fixedly installed on the upper surface of the bearing housing. The upper clamping block and the lower clamping block are arranged opposite each other and clamp together on the outer periphery of the two limiting clamping blocks.

[0016] Furthermore, the sliding pad is made of a wear-resistant material with a low coefficient of friction.

[0017] Furthermore, the upper clamping block has an upper limit protrusion on the side facing the corresponding limiting clamping block, and the limiting clamping block has a first transverse protrusion that matches the upper limit protrusion. The lower clamping block has a lower limit protrusion on the side facing the corresponding limiting clamping block, and the limiting clamping block has a second transverse protrusion that matches the lower limit protrusion. Through the convex-concave fit between the upper limit protrusion and the first transverse protrusion, and the convex-concave fit between the lower limit protrusion and the second transverse protrusion, the two limiting clamping blocks are constrained between the upper clamping block and the lower clamping block.

[0018] A method for connecting a steam turbine cylinder and a bearing housing, based on the aforementioned connection structure for connecting a steam turbine cylinder and a bearing housing, specifically includes the following steps:

[0019] Step 1, Pre-installation of bearing housing fixing and radial positioning mechanism: Fix the bearing housing on the foundation according to the design position, ensuring that its levelness and center line meet the requirements. Fix one end of the center positioning block in the designated position of the bearing housing, and extend the other end towards the cylinder.

[0020] Step 2, Installation of sliding pads and clamping blocks: Arrange two sliding pads on the upper surface of the bearing housing with their upper and lower sides facing each other, and make the two limiting clamping blocks fit tightly together. Install the upper clamping block on the side end face of the lower half of the cylinder claw, so that the upper clamping block fits with the limiting clamping block of the upper sliding pad.

[0021] Step 3, positioning of the lower half of the cylinder claw and alignment of the sliding pad: hoist the turbine into position so that the lower half of the cylinder claw overlaps the upper surface of the upper sliding pad. Adjust the position of the turbine so that the upper clamping block and the lower clamping block are aligned vertically and together clamp the two limiting clamping blocks to ensure that the sliding pad remains stationary in the vertical direction.

[0022] Step 4, cat claw positioning mechanism installation: Fix the limiting block to the lower end face of the horizontal section of the L-shaped guide block, fix the vertical section of the L-shaped guide block to the bearing housing, so that the horizontal section of the L-shaped guide block is located above the lower half of the cat claw positioning step of the cylinder, and the limiting block faces the cat claw positioning step.

[0023] Step 5, Radial Positioning Mechanism Installation and Adjustment: Fix two radial positioning blocks side by side on the front end face of the turbine in the radial direction, so that a radial positioning groove is formed between the two radial positioning blocks. Insert the other end of the center positioning block into the radial positioning groove. Install L-shaped shims on both sides of the center positioning block. Snap the L-shaped shims onto the edge of the center positioning block, so that its transverse section abuts against the upper surface of the center positioning block, and fix it to the center positioning block. The vertical section of the L-shaped shim is located in the gap between the radial positioning block and the center positioning block, and has a clearance fit with the radial positioning block.

[0024] The beneficial effects of this invention compared to the prior art are:

[0025] 1. This application adopts a connection structure with a fixed bearing housing. The lower half of the cylinder's claw directly overlaps the bearing housing and slides along the bearing housing's axial direction. When the cylinder expands due to heat, it no longer pushes the bearing housing to move. Compared with the traditional fixed-center beam and claw push-pull structure, the front bearing housing no longer bears the 20-60mm absolute expansion transmitted from the high-pressure cylinder, effectively avoiding problems such as bearing housing jamming, uneven expansion on the left and right sides, and skewing caused by excessive expansion.

[0026] 2. This application reduces thermal expansion resistance by installing a sliding pad between the lower half of the cylinder claw and the bearing housing, transforming the direct contact friction between the two into relative sliding friction between the sliding pads. This enables the unit to quickly respond to grid-side load changes under flexible operating conditions such as frequent start-stop, rapid load increases and decreases, and deep peak shaving.

[0027] 3. The radial positioning mechanism and the cat's paw positioning mechanism of this application work together to maintain the radial alignment between the cylinder and the bearing housing during the cylinder's thermal expansion and contraction. The cylinder only slides freely along the axial direction, and there will be no radial offset or vertical lifting problems. Attached Figure Description

[0028] The accompanying drawings, which form part of this invention, are provided to give a further understanding of the invention.

[0029] Figure 1 This is a side view of the lower half of the cylinder's claws resting on the bearing housing.

[0030] Figure 2 This is a top view of the radial positioning mechanism.

[0031] Figure 3 for Figure 2 A cross-sectional view at point AA.

[0032] Figure 4 This is a top view of the lower half of the cylinder's claws resting on the bearing housing.

[0033] Figure 5 A schematic diagram of the structure for clamping the upper and lower sliding pads by the clamping mechanism.

[0034] Figure 6 for Figure 5 Diagram of direction A in the middle.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1. Lower half of the cylinder cat's paw; 11. Positioning step;

[0037] 2. Radial positioning mechanism; 21. Radial positioning block; 22. Center positioning block; 23. L-shaped gasket; 24. Locking plate;

[0038] 3. Cat paw positioning mechanism; 31. L-shaped guide block; 32. Single ear stop washer; 33. Limit block;

[0039] 4. Bearing housing;

[0040] 5. Upper sliding pad; 51. Upper limit clamping block; 52. First transverse protrusion;

[0041] 6. Sliding pad; 61. Lower limit clamp; 62. Second lateral protrusion;

[0042] 7. Clamping mechanism; 71. Upper clamping block; 72. Upper limit protrusion; 73. Lower clamping block; 74. Lower limit protrusion. Detailed Implementation

[0043] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] Example 1:

[0045] See Figure 1This embodiment provides a connection structure for a steam turbine cylinder and a bearing housing, including a lower half of the cylinder claw 1, a radial positioning mechanism 2, and a claw positioning mechanism 3. The steam turbine cylinder and the bearing housing 4 are installed using a claw support method, with the lower half of the cylinder claw 1 resting on the support surface of the bearing housing 4 to bear the weight of the cylinder. The claw positioning mechanism 3 is located between the lower half of the cylinder claw 1 and the bearing housing 4, used to limit the lower half of the cylinder claw 1 laterally and vertically, while allowing it to slide freely along the axial direction of the bearing housing 4. The radial positioning mechanism 2 is installed between the steam turbine cylinder and the bearing housing 4 to achieve radial positioning between the steam turbine and the bearing housing 4, ensuring the relative radial position stability of the cylinder and the bearing housing 4 and maintaining the concentricity of the rotor and the cylinder.

[0046] When the turbine expands due to heat, the lower half of the cylinder's claw 1 slides axially along the bearing housing 4 under the guidance of the claw positioning mechanism 3, unlike the traditional claw pin structure which pushes the bearing housing 4 axially along with the cylinder expansion. Simultaneously, the radial positioning mechanism 2 ensures that the radial relative position between the cylinder and the bearing housing 4 remains unchanged, thus decoupling the bearing housing 4 from the axial expansion path of the cylinder. Through this structural design, on the one hand, the bearing housing 4 can serve as a relatively independent expansion dead point, significantly reducing the absolute expansion of the front bearing housing 4 and avoiding problems such as expansion jamming, uneven expansion on the left and right sides, and misalignment of the bearing housing 4 caused by excessive absolute expansion; on the other hand, the axial thermal expansion of the cylinder can be smoothly absorbed through the relative sliding between the claw and the bearing housing 4's support surface. Even under flexible operating conditions such as frequent start-stop, rapid load increases and decreases, and deep peak shaving, the unit can still maintain good dynamic and static clearances and shaft alignment, thereby effectively improving the unit's operational flexibility and safety.

[0047] See Figure 2 and Figure 3 In this embodiment, the radial positioning mechanism 2 includes a radial positioning block 21 and a central positioning block 22. Two radial positioning blocks 21 are provided, and are fixedly installed side-by-side on the front end face of the cylinder in the radial direction, forming a radial positioning groove between them. One end of the central positioning block 22 is fixedly connected to the bearing housing 4, and the other end is inserted axially into the radial positioning groove, thereby achieving radial positioning between the front end face of the cylinder and the bearing housing 4 through the cooperation of the radial positioning blocks 21 and the central positioning block 22.

[0048] To further control the clearance and facilitate assembly adjustment, an L-shaped gasket 23 is provided on each side of the central positioning block 22. The L-shaped gasket 23 is fastened to the edge of the central positioning block 22, with its lateral section abutting against the upper surface of the central positioning block 22 and fixed to the central positioning block 22 by bolts and locking pieces 24; its vertical section is located in the gap between the radial positioning block 21 and the central positioning block 22, and the vertical section and the radial positioning block 21 are in clearance fit. Thus, the L-shaped gasket 23 not only fills and positions the radial gap between the central positioning block 22 and the radial positioning block 21, but also avoids direct contact or jamming between the cylinder and the bearing housing 4 in the radial direction.

[0049] Preferably, the thickness of the L-shaped shim 23 can be selected or adjusted according to the pre-reserved assembly gap between the radial positioning block 21 and the central positioning block 22. By replacing the L-shaped shim 23 with shims of different thicknesses, the mating gap between the radial positioning block 21 and the central positioning block 22 can be flexibly controlled without increasing the machining accuracy requirements, thus reducing machining difficulty and improving assembly efficiency. If the L-shaped shim 23 is not provided, the gap accuracy between the central positioning block 22 and the radial positioning block 21 must be directly guaranteed, which places higher demands on the machining and assembly of related components and makes it difficult to meet the needs of on-site installation and maintenance and adjustment after long-term operation.

[0050] When the steam turbine expands due to heat, the cylinder slides relative to the bearing housing 4 along the axial direction. During this process, the axial relative sliding between the center positioning block 22 and the radial positioning block 21 is allowed, while the radial position of the center positioning block 22 relative to the front end face of the cylinder is constrained by the combined limiting action of the two radial positioning blocks 21 and the L-shaped gaskets 23 on both sides. This keeps the radial alignment between the cylinder and the bearing housing 4 stable, and the cylinder only undergoes axial thermal expansion displacement without shifting in the radial direction.

[0051] See Figure 4 and Figure 5The cat paw positioning mechanism 3 in this embodiment includes an L-shaped guide block 31, a single-ear stop washer 32, and a limiting block 33. A positioning step 11 is provided on the side end face of the lower half of the cylinder cat paw 1. This positioning step 11 protrudes outward along the side end face of the cat paw and is used to cooperate with the L-shaped guide block 31 and the limiting block 33 to limit the lower half of the cylinder cat paw 1 in the vertical and lateral directions. Specifically, the L-shaped guide block 31 includes a vertical section and a lateral section. The vertical section of the L-shaped guide block 31 is fixedly installed on the upper surface of the bearing housing 4 by bolts to the single-ear stop washer 32. The single-ear stop washer 32 is used to prevent the bolts from loosening under the vibration environment of the unit operation, ensuring the reliability of the connection between the L-shaped guide block 31 and the bearing housing 4. The transverse section extends horizontally from the upper end of the vertical section toward the cat's paw side and is located above the cat's paw positioning step 11, maintaining a vertical gap with the upper surface of the cat's paw to allow the cat's paw to slide freely axially during thermal expansion, while restricting the vertical displacement of the cat's paw. The limiting block 33 is fixedly installed on the lower end face of the transverse section of the L-shaped guide block 31 by screws and is positioned toward the cat's paw positioning step 11. A vertical assembly gap is reserved between the lower end face of the limiting block 33 and the upper end face of the cat's paw positioning step 11. The value of this gap is determined according to the thermal expansion and assembly tolerance during unit operation, ensuring that the cat's paw is not crushed by the limiting block 33 under normal operating conditions, and preventing the cat's paw from excessively lifting vertically due to abnormal vibration or pipeline forces.

[0052] Preferably, a lateral gap is also left between the side of the vertical section of the L-shaped guide block 31 near the lower half of the cylinder claw 1 and the side end face of the claw. This gap is used to constrain the lateral displacement of the claw while not hindering the claw's axial thermal expansion sliding along the bearing housing 4. The lateral gap and the vertical gap cooperate with each other to form a non-rigid constraint on the claw in the axial, vertical, and lateral directions: free sliding is allowed in the axial direction, while the vertical and lateral directions are reliably limited.

[0053] When the turbine expands due to heat, the cylinder engages with the support surface of the bearing housing 4 via a claw-like mechanism, and slides relative to the bearing housing 4 along its axial direction, guided by the aforementioned radial positioning mechanism 2 and L-shaped guide block 31. During this process, the lateral section of the L-shaped guide block 31 and the limiting block 33 mounted on it remain above the claw-like positioning step 11, and the vertical gap between them limits the maximum vertical displacement of the claw-like mechanism. Simultaneously, the vertical section of the L-shaped guide block 31 constrains the lateral displacement of the claw-like mechanism. Thus, the lower half of the cylinder claw 1 can slide smoothly along the axial direction during thermal expansion and contraction without vertical tilting or lateral displacement, thereby ensuring the relative position stability between the cylinder and the bearing housing 4.

[0054] See Figure 6The connection structure in this embodiment also includes sliding pads and a clamping mechanism 7. Two sliding pads are provided: an upper sliding pad 5 and a lower sliding pad 6. The upper sliding pad 5 and the lower sliding pad 6 are arranged vertically opposite each other and are both located between the lower half of the cylinder claw 1 and the bearing housing 4. Specifically, the upper surface of the upper sliding pad 5 is in contact with the lower surface of the lower half of the cylinder claw 1, the lower surface of the lower sliding pad 6 is in contact with the supporting surface of the bearing housing 4, and the lower surfaces of the upper sliding pad 5 and the upper surfaces of the lower sliding pad 6 are in contact with each other, forming a pair of friction pairs that can slide relative to each other along the axial direction.

[0055] The clamping mechanism 7 is installed on the side end face of the lower cylinder claw 1 and the upper surface of the bearing housing 4. Each sliding pad has a limiting clamping block at one end facing the clamping mechanism 7. The limiting clamping block of the upper sliding pad 5 is called the upper limiting clamping block 51, and the limiting clamping block of the lower sliding pad 6 is called the lower limiting clamping block 61. The upper limiting clamping block 51 and the lower limiting clamping block 61 fit tightly together, forming a clamped limiting structure. The clamping mechanism 7 includes an upper clamping block 71 and a lower clamping block 73. The upper clamping block 71 is fixedly installed on the side end face of the lower cylinder claw 1 by bolts, and the lower clamping block 73 is fixedly installed on the upper surface of the bearing housing 4 by bolts. The upper clamping block 71 and the lower clamping block 73 are arranged opposite each other and clamp together on the outer periphery of the upper limit clamping block 51 and the lower limit clamping block 61, thereby limiting and fixing the two sliding pads and the limit clamping blocks in the vertical direction, keeping them relatively stationary in the vertical direction, and preventing the sliding pads from vertically detaching or misaligning during the operation of the unit.

[0056] Preferably, the sliding pad is made of a wear-resistant material with a low coefficient of friction, such as a metal sheet with a surface friction-reducing treatment. By setting this sliding pad between the lower half of the cylinder claw 1 and the bearing housing 4, the direct contact friction between the two can be transformed into relative sliding friction between the sliding pads, effectively reducing the frictional resistance between the lower half of the cylinder claw 1 and the supporting surface of the bearing housing 4, ensuring that the cylinder can slide smoothly along the axial direction during thermal expansion and contraction, reducing the risk of jamming, and improving the unit's response speed to load changes.

[0057] To further limit the relative lateral position of the two sliding pads, this embodiment also includes a cooperating limiting protrusion structure. Specifically, the upper clamping block 71 has an upper limit protrusion 72 on the side facing the upper limit clamping block 51; correspondingly, the upper limit clamping block 51 has a first lateral protrusion 52 that matches the upper limit protrusion 72. Similarly, the lower clamping block 73 has a lower limit protrusion 74 on the side facing the lower limit clamping block 61; correspondingly, the lower limit clamping block 61 has a second lateral protrusion 62 that matches the lower limit protrusion 74. Through the interlocking of the upper limit protrusion 72 and the first transverse protrusion 52, and the interlocking of the lower limit protrusion 74 and the second transverse protrusion 62, the two limiting blocks are reliably constrained between the upper clamping block 71 and the lower clamping block 73. They can be pressed and fixed vertically and limited and stopped laterally, thereby preventing the upper sliding pad 5 and the lower sliding pad 6 from shifting laterally or misaligning with each other during axial sliding, and ensuring that the sliding pad is always in the correct working position between the cat claw and the bearing housing 4.

[0058] When the turbine expands due to heat, the cylinder causes the claw to move axially relative to the bearing housing 4. Since the upper sliding pad 5 moves with the claw, while the lower sliding pad 6 remains relatively fixed to the bearing housing 4, relative sliding occurs between them. The friction between the lower half of the claw 1 and the bearing housing 4 is borne by the low-friction contact surface between the sliding pads, allowing the claw to slide smoothly axially. During this process, the mating structure of the upper clamping block 71, the lower clamping block 73, and the limiting protrusion restricts the vertical and lateral displacement of the two sliding pads, while axial displacement is allowed, thus achieving low-friction and reliable guidance of the claw relative to the bearing housing 4.

[0059] Example 2:

[0060] This embodiment provides a method for connecting a steam turbine cylinder to a bearing housing 4, specifically including the following steps:

[0061] Step 1, Pre-installation of bearing housing 4 fixing and radial positioning mechanism 2: Fix the bearing housing 4 on the foundation according to the design position, ensuring that its levelness and center line meet the requirements, fix one end of the center positioning block 22 in the designated position of the bearing housing 4, and extend the other end toward the cylinder.

[0062] Step 2, Installation of sliding pad and clamping block: Place the sliding pad 6 on the upper surface of the bearing housing 4, aligning one end of the sliding pad 6 with the positioning end of the bearing housing 4. Fix the lower clamping block 73 to the upper surface of the bearing housing 4 with bolts, and ensure that the lower clamping block 73 is in contact with the lower limit clamping block 61 on the sliding pad 6. Place the upper sliding pad 5 above the sliding pad 6, arranging the upper sliding pad 5 and the lower sliding pad 6 vertically opposite each other, and ensure that the upper limit clamping block 51 at one end of the upper sliding pad 5 is in close contact with the lower limit clamping block 61 of the lower sliding pad 6. Install the upper clamping block 71 to the side end face of the lower half of the cylinder claw 1 with bolts, ensuring that the upper clamping block 71 is in contact with the upper limit clamping block 51 on the upper sliding pad 5.

[0063] Step 3, Positioning of the lower cylinder claw 1 and alignment of the sliding pad: Hoist the turbine into position so that the lower cylinder claw 1 overlaps the upper surface of the upper sliding pad 5. Adjust the turbine position so that the upper clamping block 71 and the lower clamping block 73 are vertically aligned and jointly clamp the two limiting blocks to ensure that the sliding pad remains stationary in the vertical direction; at this time, check whether the upper sliding pad 5 and the lower sliding pad 6 can slide smoothly relative to each other to confirm that there is no jamming;

[0064] Step 4, installation of the cat claw positioning mechanism 3: Fix the limiting block 33 to the lower end face of the transverse section of the L-shaped guide block 31 with screws, and fix the vertical section of the L-shaped guide block 31 to the bearing housing 4 with a single-ear stop washer 32 and bolts, so that the transverse section of the L-shaped guide block 31 is located above the positioning step 11 of the lower half of the cylinder cat claw 1, and the limiting block 33 faces the positioning step 11 of the cat claw; adjust the gap between the limiting block 33 and the positioning step 11 of the cat claw to meet the assembly gap value required by the design, so as to ensure that the limiting block 33 does not interfere with the positioning step 11 of the cat claw during the thermal expansion process, and at the same time effectively limit the vertical displacement of the cat claw;

[0065] Step 5, Installation and Adjustment of Radial Positioning Mechanism 2: Fix two radial positioning blocks 21 side by side on the front end face of the turbine in the radial direction, so that a radial positioning groove is formed between the two radial positioning blocks 21. Insert the other end of the center positioning block 22 into the radial positioning groove. Install L-shaped shims 23 on both sides of the center positioning block 22. Snap the L-shaped shims 23 onto the edge of the center positioning block 22, so that its transverse section abuts against the upper surface of the center positioning block 22, and fix it to the center positioning block 22 with bolts. The vertical section of the L-shaped shim 23 is located in the gap between the radial positioning block 21 and the center positioning block 22. Select an L-shaped shim 23 of appropriate thickness according to the actual assembly gap to ensure that the vertical section of the L-shaped shim 23 and the radial positioning block 21 are in clearance fit, so that the turbine can slide smoothly in the axial direction during thermal expansion without shifting in the radial direction.

[0066] Step 6, Overall Inspection and Acceptance: After completing all the above installation steps, conduct an overall inspection of the connection structure to confirm that all bolts are tightened in place, the sliding pad slides smoothly, the gap between the L-shaped guide block 31 and the limit block 33 meets the requirements, and the radial positioning mechanism 2 has a normal clearance fit; simulate the thermal expansion direction of the steam turbine, manually push the cylinder to check whether each sliding pair moves smoothly, and after confirming that there is no jamming or misalignment, the installation process of this connection structure is completed.

[0067] The above installation method, through the fixed bearing housing 4, the sliding pad, the cat claw positioning mechanism 3 and the radial positioning mechanism 2, achieves the technical effect of the cat claw sliding along the axial direction of the bearing housing 4 and the bearing housing 4 not moving when the turbine is thermally expanded. This effectively reduces the risk of jamming and misalignment caused by excessive absolute expansion and improves the alignment and safety of the unit under flexible operating conditions.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions created by the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions created by the present invention without departing from the essence and scope of the technical solutions created by the present invention.

Claims

1. A connection structure for a steam turbine cylinder and a bearing housing, characterized in that, It includes a lower half of the cylinder claw, a radial positioning mechanism, and a claw positioning mechanism. The lower half of the cylinder claw overlaps the support surface of the bearing housing. The claw positioning mechanism is set between the lower half of the cylinder claw and the bearing housing to limit the lower half of the cylinder claw in the lateral and vertical directions. The radial positioning mechanism is installed between the lower half of the turbine cylinder and the bearing housing to achieve radial positioning between the turbine cylinder and the bearing housing. The radial positioning mechanism includes a radial positioning block and a central positioning block. Two radial positioning blocks are provided and are fixedly installed side by side on the lower half end face of the cylinder in the radial direction, forming a radial positioning groove between the two radial positioning blocks. One end of the central positioning block is fixedly connected to the bearing housing, and the other end is inserted into the radial positioning groove in the axial direction, so that the lower half end face of the cylinder and the bearing housing are radially positioned through the cooperation of the radial positioning block and the central positioning block.

2. The connection structure for a steam turbine cylinder and bearing housing according to claim 1, characterized in that, An L-shaped gasket is provided on each side of the central positioning block. The L-shaped gasket is fastened to the edge of the central positioning block, and its horizontal section abuts against the upper surface of the central positioning block and is fixedly installed on the central positioning block. The vertical section of the L-shaped gasket is located in the gap between the radial positioning block and the central positioning block, and there is a clearance fit between it and the radial positioning block.

3. The connection structure for a steam turbine cylinder and bearing housing according to claim 2, characterized in that, The cat paw positioning mechanism includes an L-shaped guide block and a limiting block. A positioning step is provided on the side end face of the lower half of the cylinder cat paw. The vertical section of the L-shaped guide block is fixedly installed on the upper surface of the bearing housing. The horizontal section of the L-shaped guide block extends to the top of the cat paw positioning step. The limiting block is fixedly installed on the lower end face of the horizontal section of the L-shaped guide block and is positioned towards the cat paw positioning step. A vertical assembly gap is reserved between the lower end face of the limiting block and the upper end face of the cat paw positioning step.

4. The connection structure for a steam turbine cylinder and bearing housing according to claim 3, characterized in that, A lateral gap is left between the vertical section of the L-shaped guide block and the side face of the lower half of the cylinder claw.

5. A connection structure for a steam turbine cylinder and bearing housing according to claim 4, characterized in that, It also includes sliding pads, of which two are provided and are arranged opposite each other between the lower half of the cylinder claw and the bearing housing. The two sliding pads are in contact with each other to form a pair of friction pairs that can slide relative to each other along the axial direction.

6. The connection structure for a steam turbine cylinder and bearing housing according to claim 5, characterized in that, It also includes a clamping mechanism, which is installed on the side end face of the lower half of the cylinder claw and the upper surface of the bearing housing. Each sliding pad has a limiting clamping block at the end facing the clamping mechanism. The two limiting clamping blocks fit tightly together and together form a limiting structure clamped by the clamping mechanism.

7. A connection structure for a steam turbine cylinder and bearing housing according to claim 6, characterized in that, The clamping mechanism includes an upper clamping block and a lower clamping block. The upper clamping block is fixedly installed on the side end face of the lower half of the cylinder claw, and the lower clamping block is fixedly installed on the upper surface of the bearing housing. The upper clamping block and the lower clamping block are arranged opposite each other and clamp together on the outer periphery of the two limiting clamping blocks.

8. A connection structure for a steam turbine cylinder and bearing housing according to claim 7, characterized in that, The sliding pad is made of a wear-resistant material with a low coefficient of friction.

9. A connection structure for a steam turbine cylinder and bearing housing according to claim 7, characterized in that, The upper clamping block has an upper limit protrusion on the side facing the corresponding limiting clamping block. The limiting clamping block has a first transverse protrusion that matches the upper limit protrusion. The lower clamping block has a lower limit protrusion on the side facing the corresponding limiting clamping block. The limiting clamping block has a second transverse protrusion that matches the lower limit protrusion. Through the convex-concave fit between the upper limit protrusion and the first transverse protrusion, and the convex-concave fit between the lower limit protrusion and the second transverse protrusion, the two limiting clamping blocks are constrained between the upper clamping block and the lower clamping block.

10. A method for connecting a steam turbine cylinder and a bearing housing, characterized in that, Based on the connection structure for a steam turbine cylinder and bearing housing as described in claim 9; Specifically, the following steps are included: Step 1, Pre-installation of bearing housing fixing and radial positioning mechanism: Fix the bearing housing on the foundation according to the design position, ensuring that its levelness and center line meet the requirements. Fix one end of the center positioning block in the designated position of the bearing housing, and extend the other end towards the cylinder. Step 2, Installation of sliding pads and clamping blocks: Arrange two sliding pads on the upper surface of the bearing housing with their upper and lower sides facing each other, and make the two limiting clamping blocks fit tightly together. Install the upper clamping block on the side end face of the lower half of the cylinder claw, so that the upper clamping block fits with the limiting clamping block of the upper sliding pad. Step 3, positioning of the lower half of the cylinder claw and alignment of the sliding pad: hoist the turbine into position so that the lower half of the cylinder claw overlaps the upper surface of the upper sliding pad. Adjust the position of the turbine so that the upper clamping block and the lower clamping block are aligned vertically and together clamp the two limiting clamping blocks to ensure that the sliding pad remains stationary in the vertical direction. Step 4, cat claw positioning mechanism installation: Fix the limiting block to the lower end face of the horizontal section of the L-shaped guide block, fix the vertical section of the L-shaped guide block to the bearing housing, so that the horizontal section of the L-shaped guide block is located above the lower half of the cat claw positioning step of the cylinder, and the limiting block faces the cat claw positioning step. Step 5, Radial Positioning Mechanism Installation and Adjustment: Fix two radial positioning blocks side by side on the front end face of the turbine in the radial direction, so that a radial positioning groove is formed between the two radial positioning blocks. Insert the other end of the center positioning block into the radial positioning groove. Install L-shaped shims on both sides of the center positioning block. Snap the L-shaped shims onto the edge of the center positioning block, so that its transverse section abuts against the upper surface of the center positioning block, and fix it to the center positioning block. The vertical section of the L-shaped shim is located in the gap between the radial positioning block and the center positioning block, and has a clearance fit with the radial positioning block.

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