Two-end groove positioning-middle block welding type machine base positioning rib welding structure, assembling method and application

Abstract

This invention discloses a two-end slot positioning and intermediate support block welding type base positioning rib assembly structure, assembly method, and application, belonging to the field of base welding positioning rib assembly technology. The base structure includes an end plate, an intermediate ring plate, and a support plate. The end plate is precision-machined with positioning rib grooves to achieve precise axial and radial self-positioning of the positioning ribs. The intermediate ring plate has flame-cut rough-machined grooves, and the positioning ribs are welded to the support blocks. The assembly method includes differentiated machining of positioning rib grooves, single-piece machining of positioning ribs, positioning rib welding, and post-weld treatment. This invention combines rigid slot positioning with flexible support block welding, improving welding efficiency, reducing high-precision machining, lowering overall costs, shortening the manufacturing cycle, effectively controlling welding deformation, preventing sandblasting foreign objects from entering gaps from the source, and improving product reliability. It can be widely used in the precise assembly of bases and positioning ribs in the manufacturing of electric motors, generators, and other equipment, and is especially suitable for the production of turbine generator stator bases.

Description

Technical Field

[0001] This invention relates to the field of machine base welding positioning rib assembly technology, specifically to the welding structure, assembly method and application of machine base positioning ribs with end-end slot positioning and middle support block welding. Background Technology

[0002] The frame is the fundamental load-bearing and protective component of the generator stator. The positioning ribs, as a key connecting component between the frame and the stator core, play a crucial role in positioning the stator core and transmitting forces. Their chord pitch accuracy directly determines the stator core accuracy, which is critical for ensuring stable electromagnetic performance and reliable mechanical structure of the generator. Currently, the traditional assembly methods for welding positioning ribs to motor and generator frames mainly fall into three categories, all of which have significant technical defects, making it difficult to balance assembly accuracy, production efficiency, and manufacturing cost. These are detailed below: 1. Welding of Positioning Ribs After Individual Machining: The positioning ribs are first individually machined and then welded to the machine base one by one. Welding the positioning ribs one by one lacks an overall reference system, making chord spacing adjustment and centering difficult, and easily leading to cumulative errors. Errors inevitably occur during the individual machining of the positioning ribs, and these errors are amplified and propagated during welding. Furthermore, uncontrollable deformation caused by welding thermal stress can compromise the adjusted positional accuracy. This method requires highly skilled operators and may require repeated measurements and fine-tuning of the positioning rib positions to achieve the required accuracy, resulting in low welding efficiency, long assembly cycles, and high labor costs.

[0003] 2. Full-block connection between positioning rib and machine base: A low-precision groove is cut into the machine base ring plate, and the positioning rib is connected to the machine base via a full-block transition. Due to the low precision of the groove cutting in the machine base ring plate and the lack of effective reinforcement fixtures, the positioning reference is inaccurate, resulting in large deviations in the radial and tangential dimensions of the positioning rib. Because this structure involves a large amount of welding and many welds, welding thermal stress can easily cause structural deformation, leading to problems such as black skin and missing material in subsequent processing. This increases the processing difficulty and cost. Additional corrections and adjustments are required to compensate for the errors, further increasing processing costs and reducing production efficiency.

[0004] 3. Full Machining Method for Positioning Rib Grooves on the Base Ring Plate: This method requires high-precision machining of the positioning rib grooves on all base ring plates before welding the positioning ribs. It is highly dependent on dedicated high-precision machining equipment, resulting in high equipment procurement and maintenance costs and limited production scheduling. Furthermore, after welding the positioning ribs, a second high-precision machining process is required to position the stator core. This process is cumbersome, time-consuming, and results in low equipment utilization. Additionally, the two high-precision machining processes waste resources, significantly increasing overall manufacturing costs and leading to poor economic benefits for the enterprise.

[0005] The inherent defects of the aforementioned traditional processes have resulted in persistent difficulties in ensuring accuracy, improving efficiency, and controlling costs in the welding of machine base positioning ribs, thus failing to meet the demands for high-precision and high-efficiency production. Summary of the Invention

[0006] To address the problems of low positioning accuracy, high tooling dependence, high manufacturing cost, long production cycle, and difficulty in controlling welding deformation in traditional positioning rib welding processes, this invention proposes a two-end slot positioning-middle support block welding type machine base positioning rib welding structure, assembly method, and application. This structure enables self-positioning, high precision, and short cycle assembly of machine base welding positioning ribs, fundamentally simplifying the positioning process and improving welding efficiency.

[0007] To achieve the above-mentioned objectives, the technical solution of the present invention is as follows: An assembly method for a base positioning rib welding structure includes: Differentiated machining steps for the positioning rib grooves of the machine base: The positioning rib grooves of the end plates at both ends of the machine base body are precision machined using machining equipment; the positioning rib grooves of the middle layer ring plate are rough machined using flame cutting. The single-piece processing steps for positioning ribs are as follows: The positioning ribs are processed into strip-shaped steel plates; Positioning rib welding steps: Insert both ends of the processed positioning rib into the positioning rib grooves of the end plates at both ends of the machine base body for adaptive positioning, so that the gap between the bottom of the positioning rib groove and the top surface of the positioning rib is 0mm; install a support block in the gap between the positioning rib and the positioning rib groove of the intermediate layer ring plate, and spot weld the support block to the positioning rib and the intermediate layer ring plate respectively, and then complete the welding using the full support block welding method.

[0008] Furthermore, when machining the positioning rib groove of the end plate, the groove width is controlled to be b + (0~1) mm and the distance from the bottom of the groove to the center of the machine base is e + (1~2) mm; when machining the positioning rib groove of the intermediate layer ring plate, the groove width is controlled to be b1 > b + (10~14) mm and the distance from the bottom of the groove to the center of the machine base is e1 > e + (5~7) mm, where b is the nominal width of the square segment of the positioning rib and e is the theoretical distance from the top surface of the positioning rib to the center of the machine base.

[0009] Furthermore, when machining a single positioning rib, the width of its square segment is machined to be b (-1 to -0.5) mm, and the height is the design value h.

[0010] Furthermore, it also includes post-weld stress relief and surface treatment steps: after the machine base with the positioning ribs has been welded, it is subjected to vibration aging stress relief treatment and touch-up paint treatment in sequence before the welding is completed.

[0011] Furthermore, it also includes subsequent inspection steps: dimensional inspection of the welded positioning ribs to confirm that the chord spacing and radial dimensions of the positioning ribs meet the design requirements.

[0012] Furthermore, before the positioning ribs are welded, a pre-treatment process is carried out: before the positioning ribs and support blocks are welded to the main body of the machine base, the main body of the machine base is annealed to eliminate internal welding stress, and the non-welding areas of the main body of the machine base are sprayed with primer; after the positioning ribs are rough machined, the parts of the positioning ribs except for the end threads and non-welding areas are painted.

[0013] Furthermore, before welding the positioning ribs, first confirm the coaxiality and levelness of the machine base body. The positioning ribs are evenly distributed along the circumference of the inner wall of the machine base body, and the indexing error of adjacent positioning ribs is not greater than the design requirements. At the same time, the welds of the support block, positioning ribs, and intermediate ring plate must ensure the penetration depth and have no defects such as false welds or slag inclusions.

[0014] Furthermore, the vibration aging stress relief treatment refers to performing vibration aging on the entire machine base after welding the positioning ribs to eliminate the residual stress generated during the welding process; the paint touch-up treatment refers to applying primer to the unpainted areas on the surface of the positioning ribs caused by welding, so that the protective coating of the machine base body and the positioning ribs forms an integral whole.

[0015] On the other hand, the present invention also proposes a base positioning rib welding structure, which is obtained by the above-mentioned assembly method.

[0016] On the other hand, the present invention also provides an application in which the above-described assembly method or the above-described welding structure is used in the manufacture of electric motors and generators.

[0017] In summary, the present invention has the following advantages: 1. In this invention, the positioning rib grooves on the end plates at both ends of the base are precision machined, while the grooves on the middle ring plate are rough machined by flame cutting. The positioning ribs can achieve rapid self-positioning through the positioning rib grooves on the end plates at both ends. The remaining middle ring plates adopt a low-cost, full-block welding method, which fundamentally simplifies the positioning process, avoids the cumulative error of welding after separate processing, and improves the assembly and welding efficiency and overall structural accuracy. At the same time, it reduces the amount of high-precision processing, reduces processing difficulty, equipment load and production costs, and significantly shortens the manufacturing cycle due to the reduced amount of processing. 2. In this invention, the radial dimension of the end plate positioning rib groove is pre-processed to the compensation value according to the welding shrinkage amount. After welding, the shrinkage deformation is restored to the design dimension, thus realizing active control of welding deformation and improving the dimensional qualification rate. 3. In this invention, stress relief is achieved by annealing after welding the base but before installing the positioning ribs and their support blocks, and primer is applied to the non-welded areas; the processed positioning ribs are painted except for the end threads and welding areas; vibration aging stress relief is performed after welding the positioning ribs, and primer is applied to the areas on the positioning ribs that were not painted due to welding; the aforementioned operations implement the welding, stress relief, and painting processes in steps, reducing the generation of gaps and foreign matter from the source of the process, improving product cleanliness and reliability, and shortening the production cycle; 4. This invention adopts a differentiated processing strategy of local high precision and overall low cost, which greatly reduces the need for high precision equipment and reduces the cost of equipment procurement and maintenance; it eliminates the complex tooling of the full-block type, reduces the manpower and material input for tooling preparation and debugging, and at the same time reduces the technical level and experience requirements of operators, reducing human resources and training costs; the overall high precision processing volume is reduced, the assembly and welding process is simplified, and the overall cost is reduced. Attached Figure Description

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments, wherein: Figure 1 This is a structural schematic diagram of the stator frame of a certain type of steam turbine generator (without welded positioning ribs); Figure 2 A schematic diagram of the L-direction after machining the positioning rib grooves on the end plate and the intermediate ring plate; Figure 3 This is a schematic diagram of the machining process for a single positioning rib. Figure 4 A schematic diagram showing the welding of the positioning ribs to the end plate and the intermediate ring plate; Figure 5 This is a schematic diagram showing the radial shrinkage of the locating rib after welding. Figure 6 A three-dimensional structural diagram of a stator base with end slot positioning and middle support block welding.

[0019] The component names represented by each number in the attached diagram are as follows: 1. Base, 2. End plate, 3. Intermediate ring plate, 4. Support plate, 5. Positioning rib groove, 6. Positioning rib, 7. Support block. Detailed Implementation

[0020] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further clarifies the invention. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0021] Example 1 like Figure 1 The image shows a stator frame for a certain type of steam turbine generator (without welded positioning ribs). Its main structure includes end plates, an intermediate ring plate, and a support plate. In the un-welded positioning rib state, the positioning rib grooves need to be machined. The following describes the assembly method of a two-end groove positioning-intermediate support block welded frame positioning rib welding structure proposed in this invention, specifically including the following steps: S1. Differentiated machining of machine base positioning grooves: such as Figure 2As shown, the positioning rib grooves at both ends of the machine base body are precision machined using machining equipment to precisely control the groove width to be b + (0~1) mm and the distance from the bottom of the groove to the center of the machine base to be e + (1~2) mm; the positioning rib grooves of the intermediate layer ring plate other than the end plates are rough machined by flame cutting to control the groove width b1 > b + (10~14) mm and the distance from the bottom of the groove to the center of the machine base e1 > e + (5~7) mm, where b is the nominal width of the square segment of the positioning rib and e is the theoretical distance from the top surface of the positioning rib to the center of the machine base; like Figure 5 As shown, due to the welding stress during the welding of the positioning ribs, a radial shrinkage of approximately 2–4 mm (both sides) will occur after welding. To ensure the final radial thickness h' of the positioning ribs after machining (see...), Figure 3 It can meet the design size and structural rigidity requirements. When processing the positioning rib grooves on both ends of the machine base, the actual groove bottom to the center of the machine base, e', is 1 to 2 mm larger than the theoretical groove bottom to the center, so as to offset the effect of deformation after welding.

[0022] S2. Single-piece machining of positioning ribs: The positioning ribs are machined into strip-shaped steel plates. The width of the square segment is machined to be b (-1 to -0.5) mm, and the height is the design value h. Dimensions can be referenced. Figure 3 ; S3, Welding of positioning ribs: such as Figure 4 As shown, the fit, function, and welding methods between the end ring plate and the intermediate ring plate of the machine base and the positioning ribs are different: End plate positioning and welding of positioning ribs: Insert the two ends of the processed positioning ribs into the positioning rib grooves of the end plates at both ends of the machine base body, so that the gap between the bottom of the positioning rib groove and the top surface of the positioning rib is 0mm. Through this groove limiting method, the indexing and positioning of all positioning ribs can be quickly achieved. The intermediate ring plate is connected to the positioning ribs by a transition block: the intermediate ring plate adopts a full block welding method, that is: a block is installed in the gap between the positioning rib and the positioning rib groove of the intermediate ring plate, and the block is spot welded to the positioning rib and the intermediate ring plate respectively. In this way, the gap between the top surface of the positioning rib and the bottom of the positioning rib groove of the intermediate ring plate is 5-7mm.

[0023] It is important to note that before welding the positioning ribs, the coaxiality and levelness of the machine base body must be confirmed. The positioning ribs should be evenly distributed along the circumference of the inner wall of the machine base body, and the indexing error between adjacent positioning ribs should not exceed the design requirements. The welds between the support block and the positioning ribs, as well as the intermediate ring plate, must ensure penetration depth and be free of defects such as incomplete welds or slag inclusions. After welding, the positioning ribs must be dimensionally inspected to confirm that the chord spacing and radial dimensions of the positioning ribs meet the design requirements.

[0024] This invention can be widely applied to the precise assembly of the frame and positioning ribs in the manufacturing of equipment such as electric motors and generators, and is especially suitable for the production of turbine generator stator frames.

[0025] Example 2 To fundamentally solve the problem of foreign objects entering the small gap between the inner base and the positioning rib during sandblasting, the following process improvement measures were adopted during the implementation of this technical solution: Annealing and painting of the base: After welding the base (before the positioning ribs and support blocks are installed), the base body is annealed to eliminate internal welding stress and reduce deformation during subsequent processing; and the non-welded areas of the base body are sprayed with primer to prevent surface oxidation, rust and corrosion.

[0026] Meanwhile, after the positioning rib is rough machined, the parts of the positioning rib except for the end threads and welding area are painted.

[0027] Post-weld stress relief and surface treatment: After the positioning ribs are welded, they are not subjected to overall annealing. Instead, a vibration aging stress relief process is adopted to further eliminate the residual stress generated during the welding process. Then, the unpainted areas on the surface of the positioning ribs are touched up with primer to make the protective coating of the machine base body and the positioning ribs form a whole, ensuring its surface quality and service life.

[0028] Example 3 A type of base positioning rib welding structure, such as Figure 6 As shown, the assembly process described in Example 1 or Example 2 is used to obtain the positioning rib welding structure. This structure includes a base body and positioning ribs. The base body includes end plates at both axial ends, several intermediate ring plates, and a support plate connecting the end plates and the intermediate ring plates. The positioning ribs are strip-shaped steel plate structures, evenly distributed along the inner circumference of the base body. The positioning ribs are connected to the base body using a two-end groove positioning-intermediate support block welding method. That is, axial, radial, and indexing self-positioning is achieved through the positioning rib grooves on the end plates, and the ribs are connected to the positioning rib grooves on the intermediate ring plates through support block welding.

[0029] Specifically, the end plate is provided with positioning rib grooves precision machined using machining equipment. The two ends of the positioning ribs are inserted into the positioning rib grooves of the end plate to form rigid positioning. The gap between the bottom of the positioning rib groove and the top surface of the positioning rib is 0mm. Preferably, the width of the positioning rib groove on the end plate is b + (0~1) mm, where b is the nominal width of the square segment of the positioning rib; the distance from the bottom of the positioning rib groove to the center of the machine base is e + (1~2) mm, where e is the theoretical distance from the top surface of the positioning rib to the center of the machine base; and the machining width of the square segment of the positioning rib is b (-1~-0.5) mm.

[0030] The intermediate ring plate has a rough-machined positioning rib groove formed by flame cutting. Preferably, the groove width b1 > b + (10~14) mm, and the distance from the bottom of the groove to the center of the machine base e1 > e + (5~7) mm. A support block is installed inside the rough-machined positioning rib groove for transition connection between the positioning rib and the intermediate ring plate. The support block is fixed to the intermediate ring plate and the positioning rib by welding.

[0031] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. An assembly method for a machine base positioning rib welding structure with two end slots and a middle support block, characterized in that, include: Differentiated machining steps for the positioning rib grooves of the machine base: The positioning rib grooves of the end plates at both ends of the machine base body are precision machined using machining equipment; the positioning rib grooves of the middle layer ring plate are rough machined using flame cutting. The single-piece processing steps for positioning ribs are as follows: The positioning ribs are processed into strip-shaped steel plates; Positioning rib welding steps: Insert both ends of the processed positioning rib into the positioning rib grooves of the end plates at both ends of the machine base body for adaptive positioning, so that the gap between the bottom of the positioning rib groove and the top surface of the positioning rib is 0mm; install a support block in the gap between the positioning rib and the positioning rib groove of the intermediate layer ring plate, and spot weld the support block to the positioning rib and the intermediate layer ring plate respectively, and then complete the welding using the full support block welding method.

2. The assembly method of the end-groove positioning-middle support block welded type machine base positioning rib welding structure according to claim 1, characterized in that, When finishing the end plate positioning rib groove, control the groove width to be b + (0~1) mm and the distance from the bottom of the groove to the center of the machine base to be e + (1~2) mm; when rough machining the positioning rib groove of the intermediate layer ring plate, control the groove width to be b1 > b + (10~14) mm and the distance from the bottom of the groove to the center of the machine base to be e1 > e + (5~7) mm; where b is the nominal width of the square segment of the positioning rib and e is the theoretical distance from the top surface of the positioning rib to the center of the machine base.

3. The assembly method of the end-groove positioning-middle support block welded type machine base positioning rib welding structure according to claim 1, characterized in that, When machining a single positioning rib, the width of its square segment is b (-1 to -0.5) mm, and the height is the design value h.

4. The assembly method of the end-groove positioning-middle support block welded type machine base positioning rib welding structure according to claim 1, characterized in that, It also includes post-weld stress relief and surface treatment steps: after the machine base with the positioning ribs has been welded, vibration aging stress relief treatment and paint touch-up treatment are carried out in sequence to complete the welding.

5. The assembly method of the end-groove positioning-middle support block welded type machine base positioning rib welding structure according to claim 4, characterized in that, It also includes subsequent inspection steps: dimensional inspection of the welded positioning ribs to confirm that the chord spacing and radial dimensions of the positioning ribs meet the design requirements.

6. The assembly method of the end-groove positioning-middle support block welded type machine base positioning rib welding structure according to claim 1, characterized in that, It also includes pre-treatment steps: before the positioning ribs and support blocks are welded to the main body of the machine base, the main body of the machine base is annealed to eliminate internal welding stress, and the non-welded areas of the main body of the machine base are sprayed with primer; after the positioning ribs are rough machined, the parts of the positioning ribs except for the end threads and non-welded areas are painted.

7. The assembly method of the positioning rib welding structure of the two-end slot positioning-middle support block welding type machine base as described in claim 1, characterized in that, Before welding the positioning ribs, first confirm the coaxiality and levelness of the machine base body. The positioning ribs are evenly distributed along the circumference of the inner wall of the machine base body, and the indexing error of adjacent positioning ribs is not greater than the design requirements. At the same time, the welds of the support block, positioning ribs, and intermediate ring plate must ensure the penetration depth and have no defects such as false welds or slag inclusions.

8. The assembly method of the positioning rib welding structure of the two-end slot positioning-middle support block welding type machine base according to claim 4, characterized in that, The vibration aging stress relief treatment refers to vibrating aging the entire base after the positioning ribs are welded to eliminate residual stress generated during the welding process; the paint touch-up treatment refers to applying primer to the unpainted areas on the surface of the positioning ribs caused by welding, so that the protective coating of the base body and the positioning ribs forms an integral whole.

9. A type of machine base positioning rib welding structure with two end slots and a middle support block, characterized in that, The welding structure is obtained by the assembly method described in any one of claims 1 to 8.

10. An application characterized in that, The application includes using the assembly method according to any one of claims 1 to 8, or the welding structure according to claim 9, in the manufacture of electric motors and generators.

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