Temporary pressing process method in horizontal lamination process of stator main iron core

Abstract

The invention discloses a temporary pressing process method in a horizontal lamination process of a stator main iron core, which comprises the following steps of: flatly laying pressing plates with fan-shaped block structures in the circumferential direction on the end surface of the stator main iron core during pressing, mounting force transmission columns on a screw penetrating screw rod and a positioning screw rod to press all the pressing plates, mounting product nuts at the end heads of the screw penetrating screw rod and the positioning screw rod, and fixing the product nuts on the end surfaces of the screw penetrating screw rod and the positioning screw rod; during pressing operation, a product nut is tightened, so that the core penetrating screw and the positioning screw are matched with the force transmission column to generate tensioning force, then the tensioning force is transmitted to the pressing plate, and the pressure of the pressing plate is used for temporarily pressing the main iron core of the stator. According to the invention, under the condition that a crane cannot be used during on-site horizontal lamination of stator main iron core punching sheets and a pressing tool during vertical lamination cannot be used, product parts are fully utilized to generate pressure, and the stator main iron core is temporarily pressed through the force transmission column; and the temporary pressing work of the main iron core of the steam turbine generator stator in the on-site horizontal lamination process is realized.

Description

Technical Field

[0001] The invention relates to the field of steam turbine generators, and in particular to a temporary pressing process method during horizontal lamination of a stator main iron core. Background Art

[0002] When the stator of a steam turbine generator is running on site, the main iron core of the stator may be damaged due to various reasons. According to the previous technology for repairing the main iron core of the stator, the stator needs to be returned to the manufacturer, the stator needs to be erected, the punching sheets of the damaged stator main iron core need to be removed, and the new punching sheets need to be stacked according to the process of the new machine. When the main iron core of the stator is repaired on site, the stator is placed horizontally, and it cannot be repaired by stacking new punching sheets and pressing them according to the process in the manufacturer. The temporary pressing of the horizontal stacking on site is particularly important, because the new punching sheets when stacked horizontally are different from the vertical stacking sheets in the manufacturer. The dead weight of the punching sheets when stacked vertically will make the main iron core of the stator looser than the horizontal stacking sheets. The punching sheets will be looser when stacked horizontally on site, which will affect the next step of operation space and the judgment of the stacked length of the iron core. The temporary compaction of the stator main core during vertical stacking in the manufacturing plant requires large equipment and large-tonnage tools. The stator main core placed horizontally on site cannot use cranes and large-tonnage tools. The temporary compaction of the stator main core during horizontal stacking on site is more difficult and is also a key technology that plays a decisive role.

[0003] There are two main structures of the stator core of a steam turbine generator, a square dove-tail positioning rib and a thick pressing ring structure, and a round through-core screw and a round positioning screw and a magnetic shielding structure. In the past, the main stator cores of steam turbine generators repaired on site were all square positioning ribs and a thick pressing ring structure. The stator core of this structure only has square dove-tail positioning ribs on the back, and no through-core screws on the stator core yoke. A horizontal hydraulic press can be used for temporary compaction. The stator main core of the round through-core screw and the round positioning screw and the magnetic shielding structure has through-core screws on the yoke and cannot be temporarily removed from the stator core on site, so a horizontal hydraulic press cannot be used for temporary compaction. Therefore, there is no precedent for horizontal stacking of stator cores of this structure on site. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a temporary pressing process method for the horizontal lamination of the stator main core. It mainly relates to a temporary pressing process for the horizontal lamination of the stator main core of a steam turbine generator having a through-core screw and a positioning screw structure, and specifically includes the following steps:

[0005] S1. The stator main core with a through-core screw and a positioning screw structure is kept in a horizontal position on site. Starting from the end of the damaged end of the stator main core, the punching sheets of the damaged stator main core are removed layer by layer. During the removal of the punching sheets, the through-core screw is pulled out toward the intact end of the stator main core so that it does not affect the removal of the punching sheets at the damaged end. Then, on the basis of the retained intact stator main core, new punching sheets are stacked layer by layer horizontally. During the horizontal stacking of the new punching sheets, temporary pressing of the punching sheets is required;

[0006] S2. During temporary tightening, the through screw at the yoke of the stator main core is longer than the stator main core. Pull out the excess length of the through screw from the intact end of the stator main core, install the through screw force transfer column on the extended length of the through screw, put the through screw force transfer column on the through screw, and then install the through screw nut. The through screw nut presses the end face of the through screw force transfer column to support the excess length of the through screw on the end face of the stator main core.

[0007] S3. Install a clamping tool on the operation surface of stacking new punching sheets on the stator main core, including a pressing plate and a pressing ring. The pressing plate is fan-shaped. Multiple pressing plates are installed on the end surface of the stator main core at an angle to cover the entire operation surface of the stator main core. The pressing plate has a hole at the intersection of the through-core screw, and a circular half hole at the edge of the pressing plate at the position of the positioning screw. The pressing plate is positioned with a through-core screw and a positioning screw to prevent it from falling off. Then install the pressing ring. The pressing ring is installed on the pressing plate. There is a hole at the intersection of the pressing ring and the through-core screw. The pressing ring is positioned with a through-core screw to prevent it from falling off. The through-core screw nut is installed at the threaded position of the through-core screw end to press the pressing ring and the pressing plate.

[0008] S4. When temporarily tightening, there is excess length of the positioning screw. At one end of the stator main core stacking new punching operation surface, the positioning screw force transmission column is installed on the excess length of the positioning screw. The positioning screw force transmission column is sleeved outside the positioning screw. The positioning screw force transmission column is designed to be a round tube with a notch. The notch allows the positioning screw force transmission column to avoid the weld between the positioning screw and the machine base during installation. The end of the positioning screw force transmission column is pressed on the pressure plate, and then the positioning screw nut is installed at the thread position of the end of the positioning screw to press the positioning screw force transmission column.

[0009] S5. Tighten the through-screw nut and the positioning screw nut, and transfer the pressure to the newly stacked punching sheets of the stator main core through the through-screw force transfer column, pressure ring, pressure plate and the positioning screw force transfer column and pressure plate, so that the loose new punching sheets are close together and the stator main core is temporarily compressed.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1. The present invention realizes the temporary pressing process of the main iron core of the steam turbine generator stator with a through screw and a positioning screw structure during the on-site horizontal stacking repair process. The tightening force is exerted by the through screw nut and the positioning screw nut, and the through screw and the positioning screw cooperate with the force transmission column to transmit the pressure to the pressure plate, thereby solving the problem that the through screws cannot be temporarily removed completely on-site and cannot be temporarily pressed during the stacking process, so that the temporary pressing process of the main iron core of the steam turbine generator stator with this structure can be implemented during the on-site horizontal stacking of new punching sheets.

[0012] 2. The present invention utilizes the through-screw that affects the temporary pressing work during the on-site horizontal repair work of the stator main iron core as the main component for the pressing work, which not only achieves the temporary pressing purpose during the on-site horizontal lamination process, but also makes the tools used for temporary pressing light and can be manually carried and installed, making it possible to horizontally repair the through-screw and positioning screw structure of the steam turbine generator stator main iron core.

[0013] 3. The present invention utilizes the product through-screw nut and positioning screw nut to generate a clamping force, which is easy to operate and has a good effect. It replaces the previous process method of using a horizontal hydraulic press on site to temporarily clamp the stator main core, so that the on-site horizontal repair technology of the stator main core with a through-screw and positioning screw structure is expanded and improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Installation diagram of temporary clamping tool for stator main core.

[0015] Figure 2 This is the end face layout diagram of the temporary clamping tool for the stator main core.

[0016] Figure 3 This is the structural diagram of the through-screw force transmission column.

[0017] Figure 4 This is the structural diagram of the positioning screw force transfer column.

[0018] Figure 5 This is the structure diagram of the pressure plate.

[0019] Figure 6 This is the structure diagram of the pressure ring.

[0020] Among them: 1-stator main core; 2-through screw; 3-positioning screw; 4-punch; 5-through screw force transmission column; 6-positioning screw force transmission column; 7-pressure plate; 8-pressure ring; 9-weld; 10-through screw nut; 11-positioning screw nut; 12-machine base. DETAILED DESCRIPTION

[0021] The present application is further described below in conjunction with the accompanying drawings. The following implementation examples are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present application.

[0022] Specific implementation method 1: Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, this embodiment provides a temporary pressing process method for horizontally stacking new punching sheets 4 of a main core 1 of a steam turbine generator stator with a through screw 2 and a positioning screw 3 structure, and the method is implemented by the following steps:

[0023] S1. The stator main core 1 having the through-core screw 2 and the positioning screw 3 is kept in a horizontal position on site. Starting from the end of the damaged end of the stator main core 1, the punching sheets 4 of the damaged stator main core 1 are removed layer by layer. During the removal of the punching sheets 4, the through-core screw 2 is pulled out toward the intact end of the stator main core 1 so that it does not affect the removal of the punching sheets 4 at the damaged end. Then, on the basis of the retained intact stator main core 1, new punching sheets 4 are stacked layer by layer horizontally. During the horizontal stacking of the new punching sheets 4, temporary pressing of the punching sheets 4 is performed.

[0024] First, the through screw 2 that affects the temporary compaction is pulled out toward the intact end of the stator main core 1, so that there is space on site for removing the damaged punching sheets 4 of the stator main core 1 and stacking new punching sheets 4, and then stacking the new punching sheets 4 and temporarily compacting the new punching sheets 4 during the stacking process.

[0025] During the implementation of this step, the stator main core 1 is provided with space for temporary compression.

[0026] S2. During temporary tightening, the through screw 2 at the yoke of the stator main core 1 is longer than the stator main core 1. The excess length of the through screw 2 is pulled out from the intact end of the stator main core 1, and the through screw force transmission column 5 is installed on the extended length of the through screw 2. The through screw force transmission column 5 is sleeved on the through screw 2, and then the through screw nut 10 is installed. The through screw nut 10 presses the end face of the through screw force transmission column 5 to support the excess length of the through screw 2 on the end face of the stator main core 1.

[0027] like Figure 1 and Figure 3 As shown, during the process of horizontally stacking the new punching sheets 4 of the stator main core 1, the length of the through-hole screw 2 is greater than the length of the stator main core 1, and a small part of the through-hole screw 2 is suspended outside the end face of the stator main core 1. When the stator main core 1 is temporarily compressed, in order to utilize the through-hole screw 2 for compression, the excess length of the through-hole screw 2 relative to the stator main core 1 is covered with a cylindrical through-hole screw force transmission column 5 on the part of the through-hole screw 2 that is exposed at the intact end of the stator main core 1 and suspended, and then the through-hole screw nut 10 is installed on the end thread of the through-hole screw 2, and the through-hole screw 2 is supported on the end face of the intact end of the stator main core 1, so that the through-hole screw 2 has a force support point when the stator main core 1 is temporarily compressed.

[0028] The implementation process of this step solves the technical problem that the through-screw rods in the stator main core 1 cannot be completely removed, thus affecting temporary compaction, and the parts that affect temporary compaction are utilized in the temporary compaction work.

[0029] S3. Install a clamping tool on the operating surface of the stacked new punching sheet 4 on the stator main core 1, including a pressing plate 7 and a pressing ring 8. The pressing plate 7 is fan-shaped. Multiple pressing plates 7 are installed at an angle on the end surface of the stator main core 1 to cover the entire operating surface of the stator main core 1. The pressing plate 7 has a hole at the intersection of the through-core screw 2. The edge of the pressing plate 7 has a circular half hole at the position of the positioning screw 3. The pressing plate 7 is positioned by the through-core screw 2 and the positioning screw 3 to prevent it from falling off. Then install the pressing ring 8. The pressing ring 8 is installed on the pressing plate 7. There is a hole at the intersection of the pressing ring 8 and the through-core screw 2. The pressing ring 8 is positioned by the through-core screw 2 to prevent it from falling off. The through-core screw nut 10 is installed at the threaded position of the end of the through-core screw 2 to press the pressing ring 8 and the pressing plate 7.

[0030] like Figure 1 , Figure 2 , Figure 5 and Figure 6 As shown, a pressure plate 7 in a temporary clamping tool for the stator main core 1 is installed on the operating surface of the newly stacked punching sheet 4. In order to facilitate manual handling and installation without a crane, the pressure plate 7 is a fan-shaped block with a minimum unit structure. Each pressure plate 7 has a through screw 2 hole and a semicircular groove for a positioning screw 3. After installation, multiple pressure plates 7 completely cover the end face of the stator main core 1. Then a pressure ring 8 in the temporary clamping tool is installed. The pressure ring 8 is a full-circle ring plate covering all the through screw 2 holes. The pressure ring 8 overcomes the problem that multiple fan-shaped pressure plates 7 are difficult to form a plane during temporary clamping. The through screw 2 extends the threaded portion from the hole of the pressure plate 7 and the pressure ring 8. The through screw 2 is installed on the thread extending from the through screw 2 to temporarily press the pressure plate 7 and the pressure ring 8.

[0031] During the implementation of this step, the tools used are simple and practical, and all can be manually carried and installed, which solves the technical problem that a crane cannot be used for the temporary horizontal compaction of the stator main core, and enables the on-site horizontal stacked stator main core temporary compaction work to be efficiently and quickly implemented.

[0032] S4, when temporarily pressing, there is extra length of the positioning screw 3 at one end of the operation surface of the stator main core 1 for stacking new punching sheets 4, and the positioning screw force transmission column 6 is installed on the extra length of the positioning screw 3, and the positioning screw force transmission column 6 is sleeved outside the positioning screw 3. The positioning screw force transmission column 6 is designed to be a round tube with a notch, and the notch allows the positioning screw force transmission column 6 to avoid the weld 9 between the positioning screw 3 and the machine base 12 during installation. The end of the positioning screw force transmission column 6 is pressed on the pressure plate 7, and then the positioning screw nut 11 is installed at the threaded position of the end of the positioning screw 3 to press the positioning screw force transmission column 6;

[0033] like Figure 1 and Figure 4 As shown, when the stator main core 1 is temporarily compressed, the positioning screw 3 must also be compressed. The positioning screw force transmission column 6 is put on the length range of the vacant positioning screw 3 at the damaged end of the stator main core 1. When designing the positioning screw force transmission column 6, part of the cylinder is designed to have a small notch. The small notch allows the positioning screw force transmission column 6 to avoid the weld 9 between the positioning screw 3 and the machine base 12 during installation, so that it can be put on the outer circle of the positioning screw 3. The inner end of the positioning screw force transmission column 6 presses the pressure plate 7 in the temporary compression tool, and the positioning screw nut 11 is installed on the thread of the outer end of the positioning screw 3 to temporarily press the outer end of the positioning screw force transmission column 6.

[0034] During the implementation of this step, simple tools are used to achieve the effect of force transmission, while effectively avoiding structures that affect the installation of the tools, so that the temporary clamping effect fully meets the requirements.

[0035] S5. Tighten the through-screw nut 10 and the positioning screw nut 11, and transmit the pressure to the newly stacked punching sheet 4 of the stator main core 1 through the through-screw force transmission column 5, pressure ring 8, pressure plate 7 and the positioning screw force transmission column 6 and pressure plate 7, so that the loose new punching sheet 4 is close to each other and the stator main core 1 is temporarily compressed.

[0036] like Figure 1 and Figure 2 As shown, the through-screw nut 10 and the positioning screw nut 11 are tightened one by one in multiple circles, and the pressing force is transmitted to the pressure ring 8 and the pressure plate 7 through the through-screw force transmission column 5 and the positioning screw force transmission column 6, so that the stacked loose new punching sheets 4 are pressed against each other until the pressing force reaches the requirement, thereby achieving the purpose of temporarily tightening the stator main core 1.

[0037] During the implementation of this step, the through screw 2, the positioning screw 3 and some simple tools are used to perform horizontal temporary compaction of the stator main core 1 during the process of stacking new punching sheets 4. The product parts that affect the temporary compaction are used in the temporary compaction work, and the tightening force of the product nut is used to achieve the purpose of temporarily compacting the stator main core 1.

[0038] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A temporary pressing process method during horizontal lamination of a stator main core, which is characterized by comprising the following steps; S1. The stator main core (1) having a through-core screw (2) and a positioning screw (3) structure is kept in a horizontal position on site. Starting from the end of the damaged end of the stator main core (1), the punching sheets (4) of the damaged stator main core (1) are removed layer by layer. During the removal of the punching sheets (4), the through-core screw (2) is pulled out toward the intact end of the stator main core (1) so that it does not affect the removal of the punching sheets (4) at the damaged end. Then, new punching sheets (4) are stacked layer by layer horizontally on the basis of the retained intact stator main core (1). During the horizontal stacking of the new punching sheets (4), temporary pressing of the punching sheets (4) is performed. S2. When temporarily pressing, the through-screw (2) at the yoke of the stator main core (1) is longer than the stator main core (1). The excess length of the through-screw (2) is pulled out from the intact end of the stator main core (1). The through-screw force transmission column (5) is installed on the extended length of the through-screw (2). The through-screw force transmission column (5) is sleeved on the through-screw (2). Then, the through-screw nut (10) is installed. The through-screw nut (10) presses the end face of the through-screw force transmission column (5) to support the excess length of the through-screw (2) on the end face of the stator main core (1); S3, a clamping tool is installed on the operating surface of the stator main core (1) for stacking new punching sheets (4), including a clamping plate (7) and a clamping ring (8). The clamping plate (7) is fan-shaped. Multiple clamping plates (7) are installed at an angle on the end surface of the stator main core (1) to cover the entire operating surface of the stator main core (1). The clamping plate (7) has a hole at the intersection of the through-core screw (2). The edge of the clamping plate (7) has a circular half hole at the position of the positioning screw (3). The clamping plate (7) is positioned by the through-core screw (2) and the positioning screw (3) to prevent it from falling off. Then the clamping ring (8) is installed. The clamping ring (8) is installed on the clamping plate (7). The clamping ring (8) has a hole at the intersection of the through-core screw (2). The clamping ring (8) is positioned by the through-core screw (2) to prevent it from falling off. The through-core screw nut (10) is installed at the threaded position of the end of the through-core screw (2) to press the clamping ring (8) and the clamping plate (7); S4, when temporarily pressing, the positioning screw (3) has excess length on one end of the operating surface of the stator main core (1) for stacking new punching sheets (4), and the positioning screw force transmission column (6) is installed on the excess length of the positioning screw (3), and the positioning screw force transmission column (6) is sleeved outside the positioning screw (3). The positioning screw force transmission column (6) is designed to be a round tube with a notch, and the notch allows the positioning screw force transmission column (6) to avoid the weld (9) between the positioning screw (3) and the machine base (12) during installation. The end of the positioning screw force transmission column (6) is pressed against the pressure plate (7), and then the positioning screw nut (11) is installed at the threaded position of the end of the positioning screw (3) to press the positioning screw force transmission column (6); S5. Tighten the through-screw nut (10) and the positioning screw nut (11), and transmit pressure to the newly stacked punching sheets (4) of the stator main core (1) through the through-screw force transmission column (5), the pressure ring (8), the pressure plate (7) and the positioning screw force transmission column (6), the pressure plate (7), so that the loose new punching sheets (4) are pressed together to temporarily press the stator main core (1).

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