Integral welding type multi-shaft centrifugal compressor gear box body and welding method thereof

Abstract

The invention discloses an integral welding type multi-shaft centrifugal compressor gear box body and a welding method thereof, belongs to the technical field of compressor gear box body preparation, and solves the problems of high mold cost, long period and high weight risk caused by the adoption of an integral casting processing mode in a traditional gear box. The device specifically comprises an upper box body and a lower box body, the upper box body comprises front and rear middle panels, front and rear side plates, left and right side plates, a cover plate assembly, front and rear oil inlet pipe assemblies, a flow guide cover and reinforcing ribs; the lower box body comprises front and rear middle panels, front and rear side plates, left and right side plates, a bottom plate, an oil return cavity plate and a flow guide cover. According to the method, a mode of mainly welding and secondarily machining is adopted, so that products are circulated among different working procedures, the time is shortened to the maximum extent, and by means of the characteristics that machining is rapid and welding is convenient to control, the key size and the overall strength of the welded gearbox are guaranteed, and the subsequent influence caused by welding deformation is reduced to the minimum; the problems that the number of casting defects is large, the types are complicated, and the manufacturing period and cost are reduced are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of compressor gearbox manufacturing technology, and in particular to an integrally welded multi-shaft centrifugal compressor gearbox and its welding method. Background Technology

[0002] Compressed air, as a process gas, is widely used in industrial enterprises, with demand typically ranging from several hundred to thousands of cubic meters. For example, in steel enterprises, the compressed air output from air compressor stations is mainly used for process gas applications in blast furnace ironmaking, steelmaking, steel rolling, sintering, coking, instrumentation, backflushing, and power actuators. The pressure range of the compressed air is mostly between 0.5 and 1.0 MPa, belonging to the low-pressure compressor category (>0.2 to 1.0 MPa). A gearbox is a housing used to install the meshing gears of a centrifugal air compressor unit, which consist of one input and two outputs. In a geared multi-shaft centrifugal air compressor unit, the main motor drives the large gear through a coupling, which in turn drives the small gear shaft.

[0003] The gearbox housing is horizontally divided into upper and lower sections, traditionally manufactured using integral casting. However, with the increasing trend towards larger products, traditional integral casting has revealed several problems: First, the low reusability of molds leads to excessively high manufacturing costs per casting; second, the inherent processability of castings makes quality control difficult, and the manufacturing difficulty of large castings increases significantly; furthermore, the shortening of product manufacturing cycles poses a significant challenge to the casting process. For these reasons, large gearboxes are costly, have long lead times, and carry high quality risks, making them unsuitable for meeting enterprise production requirements. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an integrally welded multi-shaft centrifugal compressor gearbox body and its welding method, which solves the problems of high mold costs, long cycle times, and significant weight risks associated with the traditional integral casting method for gearboxes.

[0005] Firstly, in order to achieve the above objectives, the technical solution adopted by the present invention is as follows: A one-piece welded multi-shaft centrifugal compressor gearbox includes an upper housing and a lower housing installed at the bottom of the upper housing; the upper housing includes a front center panel and a rear center panel, the top of the front center panel and the rear center panel are respectively connected to a front side panel and a rear side panel; the sides of the front side panel and the rear side panel are respectively connected to a left side panel and a right side panel; a cover plate assembly is connected to the top of the front side panel and the rear side panel. The lower box includes a front center panel and a rear center panel. The bottom of the front center panel and the rear center panel are respectively connected to the front side panel and the rear side panel of the lower box. The left side panel and the right side panel of the lower box are respectively connected to the sides of the front side panel and the rear side panel of the lower box. The top of the left side panel and the right side panel of the lower box are connected to the bottom plate. The front center panel of the upper box is connected to the front center panel of the lower box, and the rear center panel of the upper box is connected to the rear center panel of the lower box.

[0006] In this design, all the center panels of the upper and lower housings are integral structures to ensure sufficient strength and rigidity to withstand working loads, while effectively reducing deformation and vibration. The front and rear panels of the upper and lower housings are all connected by welding, which improves the overall strength of the gearbox and effectively avoids casting defects, reduces manufacturing cycle and cost issues.

[0007] Furthermore, multiple semi-circular bearing mounting holes are provided on the front center panel and the rear center panel of the upper housing; multiple semi-circular bearing mounting holes are provided on the front center panel and the rear center panel of the lower housing; the semi-circular bearing mounting holes on the front center panel of the upper housing correspond to the semi-circular bearing mounting holes on the front center panel of the lower housing; the semi-circular bearing mounting holes on the rear center panel of the upper housing correspond to the semi-circular bearing mounting holes on the rear center panel of the lower housing.

[0008] Furthermore, there are three semi-circular bearing mounting holes; the three semi-circular bearing mounting holes correspond to the input shaft hole, the high-speed shaft hole, and the low-speed shaft hole, respectively.

[0009] In this design, the front center panel and the rear center panel of the lower housing are integral structures, which are completed by auxiliary machining. They include a semi-circular bearing mounting hole with "one input and two outputs", a seal mounting hole and a bearing cover, and their multi-axis holes are kept coaxial.

[0010] Furthermore, a forward oil pipe assembly and a rear oil pipe assembly are respectively provided on both sides of the upper housing; Both the forward oil pipe assembly and the rear oil pipe assembly include a main horizontal pipe and several branch vertical pipes connected to the main horizontal pipe; the main horizontal pipe of the forward oil pipe assembly and the main horizontal pipe of the rear oil pipe assembly are respectively located on the outside of the front side plate and the rear side plate of the upper housing, and the branch vertical pipes of the forward oil pipe assembly and the rear oil pipe assembly respectively pass into the semi-circular bearing mounting holes on the front center panel and the rear center panel of the upper housing.

[0011] Furthermore, a front stiffener plate and a rear stiffener plate are respectively provided on the front side panel and the rear side panel of the upper box. The front stiffener plate and the rear stiffener plate are both three-section integrated T-shaped structures. The vertical stiffener at the bottom of the T-shaped structure is connected to the outer circle of the bearing cover of the front center panel and the rear center panel of the upper box. The vertical pipes are sequentially inserted into the vertical ribs of the front and rear stiffening plates and into the semi-circular bearing mounting holes of the front and rear center panels of the upper housing. An oil inlet groove is provided between the semi-circular bearing mounting holes and the sealing body mounting holes of the front and rear center panels of the upper housing, and the oil inlet groove is connected to the vertical pipes.

[0012] In this design, lubricating oil flows into each branch vertical pipe through the main horizontal pipe, then into the oil inlet groove from the branch vertical pipe, and finally into the bearing oil inlet hole. The oil inlet groove is set as an annular groove and arranged around the bearing to ensure uniform distribution of lubricating oil. The front stiffening plate and the rear stiffening plate not only provide a channel for the lubricating oil to flow through, but also increase the lateral stiffness of the upper housing and improve the longitudinal stiffness and overall structural stability of the upper housing.

[0013] Furthermore, oil return chamber plates are provided on both sides of the front and rear side panels of the lower housing; the top of the oil return chamber plate is connected to the outer circle of the bearing seat of the front center panel and the rear center panel of the lower housing; the oil return chamber inside the oil return chamber plate is connected to the oil return hole of the bearing seat of the front center panel and the rear center panel of the lower housing respectively; the bottom of the oil return chamber plate is connected to the bottom plate, and the oil return chamber inside the oil return chamber plate is connected to the oil return hole on the bottom plate.

[0014] In this design, after the lubricating oil flows through the bearing, it flows into the return oil chamber plate from the oil hole at the bottom of the bearing chamber, and then flows out from the return oil hole on the bottom plate after passing through the return oil chamber of the return oil chamber plate.

[0015] Furthermore, an upper housing deflector is provided inside the upper housing; the upper housing deflector is connected between the front side panel and the rear side panel of the upper housing; the upper housing deflector is an upwardly curved arc structure. The lower housing is equipped with a lower housing deflector; the lower housing deflector is connected between the front side panel and the rear side panel of the lower housing; the lower housing deflector is a downwardly curved arc structure.

[0016] Furthermore, two lifting lugs are welded to the left side panel and the right side panel of the upper housing, respectively.

[0017] Secondly, based on the integral welded multi-shaft centrifugal compressor gearbox provided in the first aspect, the present invention provides a welding method for an integral welded multi-shaft centrifugal compressor gearbox, comprising the following steps: Step S1: Place the front center panel and the rear center panel of the upper box, which have been machined, on the same horizontal plane, and position and fix them according to the requirement of inner parallelism; Step S2: Vertically align the front side panel of the upper housing with the front center panel of the upper housing, and vertically align the rear side panel of the upper housing with the rear center panel of the upper housing. After aligning, fix the assembly and perform full welding. When aligning, align the semi-circular hole on the front side panel of the upper housing with the semi-circular hole on the front center panel of the upper housing, and align the semi-circular hole on the rear side panel of the upper housing with the semi-circular hole on the rear center panel of the upper housing. Welding process reinforcing ribs between the front and rear side panels of the upper housing; placing the left and right side panels of the upper housing inside the front and rear side panels of the upper housing respectively; the width of the side panels is the thickness of the upper housing; after assembly and fixation, full welding is performed. Step S3: Weld the front stiffening plate and the rear stiffening plate to the outer wall of the front side panel and the rear side panel of the upper box body respectively. Align the vertical stiffening plates at the bottom of the front and rear stiffening plates with the top of the bearing cover at the bottom of the front center panel and the rear center panel of the upper box body. Assemble and fix the lifting lugs according to the requirement of aligning them with the left side panel and the right side panel of the upper box body and weld them completely. Step S4: Perform heat treatment on the completed welded upper box body and remove the process reinforcing ribs; Step S5: Check the surface flatness of the base plate that has been machined, place the base plate on the welding platform, and mark the position of each component. Step S6: Align the front and rear side panels of the lower housing with the marked positions on the bottom plate, assemble and fix them, and then perform full welding. Add process reinforcing ribs between the front side panel and the rear side panel of the lower box body, place the left side panel and the right side panel of the lower box body between the front side panel and the rear side panel of the lower box body respectively, align the left and right sides of the bottom plate, assemble and fix them, and then perform full welding. Step S7: Align the front center panel and the rear center panel of the lower housing with the input shaft hole, high-speed shaft hole and low-speed shaft hole of the front side panel and the rear side panel of the lower housing, respectively, and then perform full welding after assembly and fixation. Step S8: Fit and fix the inner side of the U-shaped groove of the oil return chamber plate to the outer side wall of the front side plate and the rear side plate of the lower housing. Align the top of the oil return chamber plate with the bearing chambers of the front center panel and the rear center panel of the lower housing respectively. Align the bottom of the oil return chamber plate with the marked position of the bottom plate and then perform full welding after assembly and fixation. Step S9: Perform heat treatment on the welded lower box body, and then remove the process reinforcing ribs; Step S10: Connect the front center panel of the upper gearbox and the front center panel of the lower gearbox with bolts; connect the rear center panel of the upper gearbox and the rear center panel of the lower gearbox with bolts to complete the forming of the gearbox body.

[0018] Furthermore, before welding each component, a bevel is prepared, and then welding is carried out.

[0019] The beneficial effects of this invention are: The integrally welded multi-shaft centrifugal compressor gearbox of this invention employs a welding process to weld the various plates into a complete gearbox structure, thereby improving the overall strength of the gearbox and effectively avoiding casting defects, reducing manufacturing cycle time, and lowering costs. Simultaneously, to reduce the impact of welding stress on the gearbox's machining accuracy, a two-stage heat treatment process is implemented after welding. The first heat treatment eliminates residual stress generated during welding, while the second heat treatment is performed after rough machining and before finish machining to further eliminate stress in the welded gearbox.

[0020] The integral welded multi-shaft centrifugal compressor gearbox welding method of the present invention adopts welding as the main method and machining as the auxiliary method to form the welded gearbox. By formulating a reasonable process route and controlling the welding process, the product can be transferred between different processes, minimizing the time. With the advantages of fast and high precision machining and the easy control of the welding process, the key dimensions of the welded gearbox are guaranteed, the impact of welding deformation on subsequent processes is minimized, and the production cycle is fully controllable, solving the quality, cycle and cost problems caused by integral casting and mold pressing. Attached Figure Description

[0021] Figure 1 This is a front-view side view of the gearbox of an integrally welded multi-shaft centrifugal compressor according to the present invention; Figure 2 This is a rear-view side view of the gearbox of an integrally welded multi-shaft centrifugal compressor according to the present invention; Figure 3 This is a front-view side view of the upper housing of the gearbox of an integrally welded multi-shaft centrifugal compressor according to the present invention; Figure 4 This is a rear-view side view of the upper housing of an integrally welded multi-shaft centrifugal compressor gearbox according to the present invention; Figure 5 This is a front view of the upper housing of the gearbox of an integrally welded multi-shaft centrifugal compressor according to the present invention; Figure 6 for Figure 5 A front sectional view; Figure 7 for Figure 5 A sectional view of the CC section; Figure 8 This is a front-view side view of the lower housing of an integrally welded multi-shaft centrifugal compressor gearbox according to the present invention. Figure 9 This is a rear-view side view of the lower housing of the gearbox of an integrally welded multi-shaft centrifugal compressor according to the present invention; Figure 10 This is a front view of the lower housing of the gearbox of an integrally welded multi-shaft centrifugal compressor according to the present invention; Figure 11 for Figure 10 The front sectional view.

[0022] Figure label: 1. Upper housing; 2. Lower housing; 3. Front center panel of upper housing; 4. Rear center panel of upper housing; 5. Front side panel of upper housing; 6. Rear side panel of upper housing; 7. Left side panel of upper housing; 8. Right side panel of upper housing; 9. Cover plate assembly; 10. Lifting lug; 11. Inlet oil pipe assembly; 12. Rear oil pipe assembly; 13. Front stiffener; 14. Rear stiffener; 15. Upper housing fairing; 16. Front center panel of lower housing; 17. Rear center panel of lower housing; 18. Bottom plate; 19. Front side panel of lower housing; 20. Rear side panel of lower housing; 21. Oil return chamber plate; 22. Left side panel of lower housing; 23. Right side panel of lower housing; 24. Lower housing fairing; Detailed Implementation The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Specific embodiments of the present invention are described below to facilitate understanding by those skilled in the art. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various modifications are obvious as long as they fall within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0023] Example 1 like Figure 1 and Figure 2 As shown, this embodiment provides an integrally welded multi-shaft centrifugal compressor gearbox, which solves the problems of high mold cost, long cycle and high weight risk caused by the traditional gearbox being manufactured by integral casting; it specifically includes: an upper housing 1 and a lower housing 2 installed at the bottom of the upper housing 1.

[0024] like Figures 3-5 As shown, the upper housing 1 includes a front center panel 3, a rear center panel 4, a front side panel 5, a rear side panel 6, a left side panel 7, a right side panel 8, a cover assembly 9, a lifting lug 10, a forward oil pipe assembly 11, a rear oil pipe assembly 12, a front stiffener 13, a rear stiffener 14, and an upper housing fairing 15. The tops of the front center panel 3 and the rear center panel 4 are respectively connected to the front side panel 5 and the rear side panel 6; the sides of the front side panel 5 and the rear side panel 6 are respectively connected to the left side panel 7 and the right side panel 8; and the tops of the front side panel 5 and the rear side panel 6 are connected to the cover assembly 9. like Figures 8-10As shown, the lower housing 2 includes a front center panel 16, a rear center panel 17, a bottom plate 18, a front side panel 19, a rear side panel 20, an oil return chamber plate 21, a left side panel 22, a right side panel 23, and a flow guide 24. The bottom of the front center panel 16 and the rear center panel 17 are respectively connected to the front side panel 19 and the rear side panel 20; the sides of the front side panel 19 and the rear side panel 20 are respectively connected to the left side panel 22 and the right side panel 23; the top of the left side panel 22 and the right side panel 23 are connected to the bottom plate 18.

[0025] The front center panel 3 of the upper box is connected to the front center panel 16 of the lower box, and the rear center panel 4 of the upper box is connected to the rear center panel 17 of the lower box.

[0026] Three semi-circular bearing mounting holes are provided on the front center panel 3 and the rear center panel 4 of the upper housing, and three semi-circular bearing mounting holes are provided on the front center panel 16 and the rear center panel 17 of the lower housing. These three semi-circular bearing mounting holes correspond to the input shaft hole, the high-speed shaft hole, and the low-speed shaft hole, respectively. The semi-circular bearing mounting holes on the front center panel 3 of the upper housing correspond to the semi-circular bearing mounting holes on the front center panel 16 of the lower housing; the semi-circular bearing mounting holes on the rear center panel 4 of the upper housing correspond to the semi-circular bearing mounting holes on the rear center panel 17 of the lower housing.

[0027] The upper housing front center panel 3, the upper housing rear center panel 4, the lower housing front center panel 16, and the lower housing rear center panel 17 are an integral structure, which is completed by auxiliary machining. It includes a semi-circular bearing mounting hole with "one input and two outputs" and a seal mounting hole, and its multi-axis holes are kept on the same axis.

[0028] The upper housing 1 is provided with a forward oil pipe assembly 11 and a rear oil pipe assembly 12 on both sides respectively; both the forward oil pipe assembly 11 and the rear oil pipe assembly 12 include a main horizontal pipe and several branch vertical pipes connected to the main horizontal pipe; the main horizontal pipe of the forward oil pipe assembly 11 and the main horizontal pipe of the rear oil pipe assembly 12 are respectively located on the outside of the front side plate 5 and the rear side plate 6 of the upper housing, and the branch vertical pipes of the forward oil pipe assembly 11 and the branch vertical pipes of the rear oil pipe assembly 12 are respectively connected to the semi-circular bearing mounting holes on the front center panel 3 and the rear center panel 4 of the upper housing.

[0029] like Figure 7As shown, front stiffener 13 and rear stiffener 14 are respectively provided on the outer sides of the front side plate 5 and the rear side plate 6 of the upper housing. The front stiffener 13 and the rear stiffener 14 are both three-section integrated T-shaped structures. The vertical ribs at the bottom of the T-shaped structure are connected to the outer circles of the bearing covers of the front center panel 3 and the rear center panel 4 of the upper housing. The vertical pipes are sequentially inserted into the vertical ribs of the front stiffener 13 and the rear stiffener 14 and the semi-circular bearing mounting holes of the front center panel 3 and the rear center panel 4 of the upper housing. An oil inlet groove is provided between the semi-circular bearing mounting holes of the front center panel 3 and the rear center panel 4 of the upper housing and the sealing body mounting hole. The oil inlet groove is connected to the vertical pipes of the forward oil pipe assembly 11 and the rear oil pipe assembly 12. Lubricating oil flows into each branch vertical pipe through the main horizontal pipe, then into the oil inlet groove from the branch vertical pipe, and finally into the bearing oil inlet hole. The oil inlet groove is set as an annular groove and arranged around the bearing to ensure uniform distribution of lubricating oil. The front stiffening plate 13 and the rear stiffening plate 14 not only provide channels for the flow of lubricating oil, but also increase the lateral stiffness of the upper box and improve the longitudinal stiffness and overall structural stability of the upper box.

[0030] Oil return chamber plates 21 are provided on both sides of the front side panel 19 and the rear side panel 20 of the lower housing. The top of the oil return chamber plate 21 is connected to the outer circle of the bearing seat of the front center panel 16 and the rear center panel 17 of the lower housing. The oil return chamber inside the oil return chamber plate 21 is connected to the oil return hole of the bearing seat of the front center panel 16 and the rear center panel 17 of the lower housing, respectively. The bottom of the oil return chamber plate 21 is connected to the bottom plate 18, and the oil return chamber inside the oil return chamber plate 21 is connected to the oil return hole on the bottom plate 18, respectively. After the lubricating oil flows through the bearing, it flows into the oil return chamber plate 21 from the oil hole at the bottom of the bearing seat, and then flows out from the oil return hole on the bottom plate 18 after passing through the oil return chamber of the oil return chamber plate 21.

[0031] like Figure 6 As shown, an upper housing deflector 15 is installed inside the upper housing; the upper housing deflector 15 is connected between the front side panel 5 and the rear side panel 6 of the upper housing; the upper housing deflector 15 has an upwardly curved arc structure. Figure 11 As shown, a lower housing deflector 24 is provided inside the lower housing; the lower housing deflector 24 is connected between the front side panel 19 and the rear side panel 20 of the lower housing; the lower housing deflector 24 is a downwardly curved arc structure.

[0032] Two lifting lugs 10 are welded to the left side plate 7 and the right side plate 8 of the upper box body, respectively.

[0033] like Figures 3-7 As shown, the upper box 1 has a shape with a smaller top and a larger bottom, and its upper width is smaller than its lower width, forming a stable inverted trapezoidal structure.

[0034] like Figures 8-11As shown, the lower box 2 has a shape with a larger top and a smaller bottom, and its upper width is greater than its lower width, forming a stable trapezoidal structure that fits into the inverted trapezoidal structure of the upper box 1.

[0035] Example 2 This embodiment, based on the integral welded multi-shaft centrifugal compressor gearbox provided in Embodiment 1, provides a welding method for the integral welded multi-shaft centrifugal compressor gearbox, including the following steps: Step S1: Place the front center panel 3 and the rear center panel 4 of the upper box, which have been machined, on the same horizontal plane, and position and fix them according to the requirement of inner parallelism.

[0036] Step S2: Make bevels on the front side panel 5, rear side panel 6, left side panel 7, and right side panel 8 of the upper box. The front side panel 5 of the upper box is perpendicularly connected to the front center panel 3 of the upper box, and the rear side panel 6 of the upper box is perpendicularly connected to the rear center panel 4 of the upper box. After connection, the panels are assembled and fixed and fully welded. When connecting, the semi-circular hole on the front side panel 5 of the upper box is aligned with the semi-circular hole on the front center panel 3 of the upper box, and the semi-circular hole on the rear side panel 6 of the upper box is aligned with the semi-circular hole on the rear center panel 4 of the upper box. Welding reinforcement ribs between the front panel 5 and the rear panel 6 of the upper box ensures that the front panel 5 and the rear panel 6 of the upper box are parallel to each other and perpendicular to the center panel.

[0037] Place the left side panel 7 and the right side panel 8 of the upper box body inside the front side panel 5 and the rear side panel 6 of the upper box body, respectively. The width of the side panel is the thickness of the upper box body. Align the left and right inner sides of the front center panel 3 and the rear center panel 4 of the upper box body, and after assembly and fixation, perform full welding to ensure that there are no misalignments between the left and right side panels and the front and rear center panels.

[0038] Step S3: Make bevels for the front stiffening plate 13 and rear stiffening plate 14 that have completed auxiliary machining, and weld the front stiffening plate 13 and rear stiffening plate 14 to the outer walls of the front side panel 5 and the rear side panel 6 of the upper box body respectively; align the vertical stiffening plates of the lower section of the front stiffening plate 13 and the rear stiffening plate 14 with the top of the bearing cover at the bottom of the front center panel 3 and the rear center panel 4 of the upper box body, and fit them tightly against the wall surface, assemble and fix them and weld them completely. Make a bevel on the lifting lug 10, assemble and fix it according to the requirement of aligning it with the left side plate 7 and the right side plate 8 of the upper box, and then weld it completely.

[0039] Step S4: Heat treat the welded upper box and remove the process reinforcing ribs; then rough machine the upper box, and heat treat it again; finally, finish machine the upper box to achieve the final shape of the upper box.

[0040] Step S5: Check the surface flatness of the base plate 18 after auxiliary machining, place the base plate 18 on the welding platform, and mark the position of each component.

[0041] Step S6: Make bevels on the front side plate 19, rear side plate 20, left side plate 22, and right side plate 23 of the lower housing; align the front side plate 19 and rear side plate 20 of the lower housing with the marked positions on the bottom plate 18, and ensure their verticality. After assembly and fixing, perform full welding. A process reinforcing rib is added between the front side panel 19 and the rear side panel 20 of the lower box to ensure that the front side panel 19 and the rear side panel 20 of the lower box are parallel to each other and perpendicular to the bottom plate 18. Place the left side panel 22 and the right side panel 23 of the lower housing between the front side panel 19 and the rear side panel 20 of the lower housing, respectively, align them with the left and right sides of the bottom plate 18, and then perform full welding after assembly and fixation; ensure that the side panels are not misaligned with the front and rear side panels and fit tightly.

[0042] Step S7: Align the front center panel 16 and rear center panel 17 of the lower housing, which have been machined with auxiliary machining, with the input shaft hole, high-speed shaft hole and low-speed shaft hole of the front side panel 19 and rear side panel 20 of the lower housing, respectively. At the same time, ensure that the inner side of the front center panel and the rear center panel are tightly fitted with the inner wall of the front side panel and the rear side panel without any misalignment. After assembly and fixing, perform full welding.

[0043] Step S8: Make a bevel on the oil return plate 21, and fix the inner side of the U-shaped groove of the oil return plate 21 to the outer side wall of the front side plate 19 and the rear side plate 20 of the lower housing. Align the top of the oil return plate 21 with the bearing chambers of the front center panel 16 and the rear center panel 17 of the lower housing and fit them tightly. Align the bottom of the oil return plate 21 with the marked position of the bottom plate 18 and fix them together before performing full welding.

[0044] Step S9: Heat treat the welded lower box body, then remove the process reinforcing ribs; then rough machine the lower box body, heat treat it again, and then finish machine the lower box body to finally achieve the forming of the lower box body.

[0045] Step S10: Connect the front center panel 3 of the upper housing and the front center panel 16 of the lower housing with bolts; connect the rear center panel 4 of the upper housing and the rear center panel 17 of the lower housing with bolts, align the upper housing 1 and the lower housing 2, and finish the housing to complete the forming of the gearbox.

[0046] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention and should be understood as not limiting the scope of protection of the invention to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed herein without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of the invention.

Claims

1. A one-piece welded multi-shaft centrifugal compressor gearbox, characterized in that: It includes an upper box (1) and a lower box (2) installed at the bottom of the upper box (1); The upper box (1) includes a front center panel (3) and a rear center panel (4). The top of the front center panel (3) and the rear center panel (4) are respectively connected to the front side panel (5) and the rear side panel (6). The sides of the front side panel (5) and the rear side panel (6) are respectively connected to the left side panel (7) and the right side panel (8). The top of the front side panel (5) and the rear side panel (6) are connected to the cover assembly (9). The lower housing (2) includes a front center panel (16) and a rear center panel (17). The bottom of the front center panel (16) and the rear center panel (17) are respectively connected to the front side panel (19) and the rear side panel (20). The sides of the front side panel (19) and the rear side panel (20) are respectively connected to the left side panel (22) and the right side panel (23). The top of the left side panel (22) and the right side panel (23) are connected to the bottom plate (18). The upper box front center panel (3) and the lower box front center panel (16) are connected, and the upper box rear center panel (4) and the lower box rear center panel (17) are connected.

2. The integrally welded multi-shaft centrifugal compressor gearbox according to claim 1, characterized in that: Multiple semi-circular bearing mounting holes are provided on the front center panel (3) and the rear center panel (4) of the upper housing; multiple semi-circular bearing mounting holes are provided on the front center panel (16) and the rear center panel (17) of the lower housing; the semi-circular bearing mounting holes of the front center panel (3) of the upper housing correspond to the semi-circular bearing mounting holes of the front center panel (16) of the lower housing; the semi-circular bearing mounting holes of the rear center panel (4) of the upper housing correspond to the semi-circular bearing mounting holes of the rear center panel (17) of the lower housing.

3. The integrally welded multi-shaft centrifugal compressor gearbox according to claim 2, characterized in that: There are three semi-circular bearing mounting holes; the three semi-circular bearing mounting holes correspond to the input shaft hole, the high-speed shaft hole, and the low-speed shaft hole, respectively.

4. The integrally welded multi-shaft centrifugal compressor gearbox according to claim 2, characterized in that: The upper housing (1) is provided with a forward oil pipe assembly (11) and a rear oil pipe assembly (12) on both sides respectively. Both the forward oil pipe assembly (11) and the rear oil pipe assembly (12) include a main horizontal pipe and several branch vertical pipes connected to the main horizontal pipe; the main horizontal pipe of the forward oil pipe assembly (11) and the main horizontal pipe of the rear oil pipe assembly (12) are respectively located on the outside of the front side plate (5) of the upper housing and the rear side plate (6) of the upper housing, and the branch vertical pipes of the forward oil pipe assembly (11) and the branch vertical pipes of the rear oil pipe assembly (12) are respectively connected to the semi-circular bearing mounting holes on the front center panel (3) and the rear center panel (4) of the upper housing.

5. The integrally welded multi-shaft centrifugal compressor gearbox according to claim 4, characterized in that: The front side panel (5) and the rear side panel (6) of the upper box are respectively provided with a front stiffener plate (13) and a rear stiffener plate (14). The front stiffener plate (13) and the rear stiffener plate (14) are both three-section integrated T-shaped structures. The vertical stiffener at the bottom of the T-shaped structure is connected to the outer circle of the bearing cover of the front center panel (3) and the rear center panel (4) of the upper box. The vertical pipes are inserted sequentially into the vertical ribs of the front stiffener plate (13) and the rear stiffener plate (14) and into the semi-circular bearing mounting holes of the front center panel (3) and the rear center panel (4) of the upper housing; an oil inlet groove is provided between the semi-circular bearing mounting holes of the front center panel (3) and the rear center panel (4) of the upper housing and the sealing body mounting hole, and the oil inlet groove is connected to the vertical pipes.

6. The integrally welded multi-shaft centrifugal compressor gearbox according to claim 4, characterized in that: Oil return chamber plates (21) are provided on both sides of the front side panel (19) and the rear side panel (20) of the lower housing. The top of the oil return chamber plate (21) is connected to the outer circle of the bearing seat of the front center panel (16) and the rear center panel (17) of the lower housing. The oil return chamber inside the oil return chamber plate (21) is connected to the oil return hole of the bearing seat of the front center panel (16) and the rear center panel (17) of the lower housing, respectively. The bottom of the oil return chamber plate (21) is connected to the bottom plate (18), and the oil return chamber inside the oil return chamber plate (21) is connected to the oil return hole on the bottom plate (18), respectively.

7. The integrally welded multi-shaft centrifugal compressor gearbox according to claim 1, characterized in that: The upper housing (1) is provided with an upper housing guide shroud (15); the upper housing guide shroud (15) is connected between the front side plate (5) of the upper housing and the rear side plate (6) of the upper housing; the upper housing guide shroud (15) is an upwardly curved arc structure; The lower housing (2) is provided with a lower housing guide shroud (24); the lower housing guide shroud (24) is connected between the front side plate (19) and the rear side plate (20) of the lower housing; the lower housing guide shroud (24) is a downwardly curved arc structure.

8. The integrally welded multi-shaft centrifugal compressor gearbox according to claim 1, characterized in that: Two lifting lugs (10) are welded to the left side plate (7) and the right side plate (8) of the upper box respectively.

9. A welding method for an integrally welded multi-shaft centrifugal compressor gearbox body according to any one of claims 1 to 8, characterized in that, Includes the following steps: Step S1: Place the front center panel (3) and the rear center panel (4) of the upper box body, which have been completed with auxiliary machining, on the same horizontal plane, and position and fix them according to the requirement of inner parallelism; Step S2: Vertically connect the front side panel (5) of the upper box to the front center panel (3) of the upper box, and vertically connect the rear side panel (6) of the upper box to the rear center panel (4) of the upper box. After connecting, fix the assembly and perform full welding. When connecting, align the semi-circular hole on the front side panel (5) of the upper box with the semi-circular hole on the front center panel (3) of the upper box, and align the semi-circular hole on the rear side panel (6) of the upper box with the semi-circular hole on the rear center panel (4) of the upper box. Welding process reinforcing ribs between the front side panel (5) and the rear side panel (6) of the upper box body, placing the left side panel (7) and the right side panel (8) of the upper box body inside the front side panel (5) and the rear side panel (6) of the upper box body respectively, the width of the side panel is the thickness of the upper box body; after assembly and fixing, full welding is performed; Step S3: Weld the front stiffener plate (13) and the rear stiffener plate (14) to the outer walls of the front side panel (5) and the rear side panel (6) of the upper box body respectively. Align the vertical stiffeners of the lower section of the front stiffener plate (13) and the rear stiffener plate (14) with the top of the bearing cover at the bottom of the front center panel (3) and the rear center panel (4) of the upper box body. Assemble and fix the lifting lug (10) according to the requirement of aligning it with the left side panel (7) and the right side panel (8) of the upper box body and weld it completely. Step S4: Perform heat treatment on the welded upper box (1) and remove the process reinforcing ribs; Step S5: Check the surface flatness of the base plate (18) that has been machined, place the base plate (18) on the welding platform, and mark the position of each component; Step S6: Align the front side panel (19) and rear side panel (20) of the lower housing with the marked positions of the bottom plate (18), assemble and fix them, and then perform full welding; Add process reinforcing ribs between the front side plate (19) and the rear side plate (20) of the lower box body, place the left side plate (22) and the right side plate (23) of the lower box body between the front side plate (19) and the rear side plate (20) of the lower box body respectively, align them with the left and right sides of the bottom plate (18), and then perform full welding after assembly and fixation. Step S7: Align the front center panel (16) and the rear center panel (17) of the lower housing with the input shaft hole, high-speed shaft hole and low-speed shaft hole of the front side panel (19) and the rear side panel (20) of the lower housing, respectively, and perform full welding after assembly and fixing. Step S8: Fit and fix the inner side of the U-shaped groove of the oil return plate (21) to the outer side wall of the front side plate (19) and the rear side plate (20) of the lower housing. Align the top of the oil return plate (21) with the bearing chambers of the front center panel (16) and the rear center panel (17) of the lower housing respectively. Align the bottom of the oil return plate (21) with the marked position of the bottom plate (18) and then perform full welding after assembly and fixation. Step S9: Perform heat treatment on the welded lower box (2), and then remove the process reinforcing ribs; Step S10: Connect the front center panel (3) of the upper housing and the front center panel (16) of the lower housing with bolts; connect the rear center panel (4) of the upper housing and the rear center panel (17) of the lower housing with bolts to complete the forming of the gearbox.

10. The welding method for the integral welded multi-shaft centrifugal compressor gearbox body according to claim 9, characterized in that: Before welding each component, a bevel is made, and then welding is carried out.

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