Large-diameter multi-section combined gear machining method

Abstract

The invention relates to a large-diameter multi-section combined type gear machining method, and belongs to the technical field of combined type gear machining. During machining, firstly, rough machining and semi-finish machining are independently carried out on arc section tooth blocks, aging treatment is alternately arranged in the middle to eliminate stress, then the multiple arc section tooth blocks are spliced into two half-shaped gears, and the two half-shaped gears are machined; the two half gears are assembled into the full-circle gear through the connecting tool, finally, the large vertical lathe and the large gear hobbing machine are adopted for finish machining, and the full-circle gear is directly assembled after gear finish milling, so that deformation caused by independent machining of the arc tooth block and installation errors caused during assembly are avoided, the part precision and assembly requirements can be met after machining, and the machining efficiency is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of combined gear processing, and in particular to a method for processing large-diameter multi-segment combined gears. Background Art

[0002] Multi-segment combination gears are a common structural form of transmission parts. They are generally composed of 6-12 arc segment gear blocks of the same length and hubs, which can form a full circle or a partial circle. The maximum diameter of the gear components can reach or exceed φ16 meters. The gear accuracy is GB / T10095-8 level. The tooth shape is generally a standard straight tooth. The center of the length of each arc segment gear block is a tooth groove, and the two end faces of the length are a half tooth groove structure. The structure is shown in the figure below. Figure 1 and Figure 2 shown.

[0003] The machining of multi-segment gears requires different methods depending on the assembly method. Currently, similar multi-segment gears with relatively small diameters (less than 10 meters in diameter) are mostly machined individually in sections and then assembled for direct use. Each segment is finished using a high-precision CNC machining center with specialized tools. This machining method eliminates the reliance on large vertical lathes and large gear hobbing machines, but it also presents some challenges. Due to the limitations of large precision equipment, it is difficult to maintain the machining accuracy and a certain degree of interchangeability of individual segments for very large diameter (12-16 meters in diameter) multi-segment gears, significantly impacting product performance. Therefore, we have proposed a new method for machining large-diameter multi-segment gears. Summary of the Invention

[0004] In response to the defects of the existing technology, the present invention provides a method for processing large-diameter multi-segment combined gears, which can avoid the deformation and assembly error problems caused by separate processing of arc segment tooth blocks, and effectively ensure that the accuracy of the processed gears meets the requirements.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: A method for machining a large-diameter, multi-segment combined gear. The combined gear is composed of multiple arc-segment gear blocks of the same length assembled through a wheel hub, with a center angle of no more than 180 degrees. During machining, each arc-segment gear block is first rough-machined and semi-finished individually. The semi-finished arc-segment gear blocks are then assembled into two half-gears through the wheel hub. A connecting tool is used to assemble the two half-gears into a full-circle gear with symmetrical teeth. Finally, the full-circle gear is fine-machined to ensure that the tooth profile meets design requirements.

[0006] Furthermore, the rough machining of the arc segment tooth segment includes the following steps: (1) Rough machining of the arc segment gear block: On a CNC gantry boring and milling machine, rough machining is performed on the arc segment gear block's thickness, length end large surface, inner and outer circle parts, and then the tempering process is performed to ensure the hardness requirements of the drawing; (2) Semi-finishing of the arc segment gear block: On a CNC gantry boring and milling machine, semi-finish the thickness and length end surface, inner and outer circle parts of the arc segment gear block; (3) Milling the reference tooth groove of the arc segment tooth block: On the CNC gantry boring and milling machine, align and level the arc segment tooth block according to the center line and end face, and press it tightly. The machine tool uses the outer circle of the arc segment tooth block as the reference to find the center of rotation of the part, align the two ends of the length, and use the tooth groove at the center of the length as the 0-position tooth groove. Mill out the groove shape of each tooth and process it to a certain depth as the reference groove shape to facilitate the boring machine to align and process the tool; (4) Rough milling of the tooth groove with the arc segment tooth block. Place the arc segment tooth block flat on the rotary table of the boring machine, and align the center line of the part with the center line of the rotary table. Equip the spindle of the boring machine with a finger milling cutter, rotate the table according to the angle of each tooth groove, and combine the translation of the boring spindle to align the center of each tooth groove with the center of the spindle, and process each tooth groove.

[0007] Furthermore, when the arc segment tooth block is rough milled, the angle θ of each tooth groove is 360° / Z, where Z is the number of teeth in the full circle.

[0008] Furthermore, the semi-finishing of the arc segment tooth segment includes the following steps: (1) Semi-finishing of the arc segment gear block shape, including the thickness and length end large surface, inner and outer circle parts; (2) Semi-finish milling of the reference tooth groove of the arc segment tooth block, the method is the same as the rough machining step (3); (3) Semi-finish milling of the tooth groove of the arc segment tooth block, the method is the same as the rough machining step (4).

[0009] Furthermore, aging treatment is arranged between rough machining and semi-finishing to eliminate machining stress.

[0010] Furthermore, the center angle of the half gear is the same as the center angle of the combined gear. When assembling the full circle gear, the centers of the two half gears are aligned and the teeth are arranged symmetrically. If the center angle of the half gear is less than 180 degrees, two connecting tools are set in the gap between the end faces of the two half gears and connected to the hubs on both sides respectively, and the two half gears are assembled into a full circle gear with symmetrical teeth. If the center angle of the half gear is equal to 180 degrees, the hubs on both sides can be directly fixed and connected to assemble the full circle gear.

[0011] Furthermore, when the center angle of the half gear is less than 180 degrees, the two connecting tools are of the same size and are symmetrically arranged. The size of the connecting tool is designed to just fill the gap, thereby assembling the two half gears into a full-circle gear with symmetrical teeth.

[0012] Furthermore, the tooth profile finishing of the full circle gear is carried out on a large vertical lathe and a large gear hobbing machine, and after processing is completed, the tooth profile is guaranteed to meet the accuracy requirements.

[0013] Furthermore, when finishing a full-circle gear, a special centering mechanism is used to ensure that the symmetrical center plane of the disc milling cutter passes through the rotation center of the gear being processed. The special centering mechanism includes a base, a telescopic rod and a V-shaped positioning block. The disc milling cutter is machined with a tool reference surface. When in use, first install the special centering mechanism on the gear hobbing machine tool holder, then install the disc milling cutter, adjust the telescopic rod so that the V-shaped positioning block extends and contacts the tool reference surface of the disc milling cutter, use a feeler gauge to check the gap between the two side surfaces of the disc milling cutter and the two side surfaces of the V-shaped positioning block, adjust the position of the disc milling cutter so that the gaps on both sides are consistent, and then perform fine gear milling.

[0014] Furthermore, the tooth shape of the arc segment tooth block is a standard straight tooth, the center of each arc segment length is a tooth groove, and the two end surfaces of the length are half tooth grooves.

[0015] Beneficial effects: The processing method of the present invention provides a general processing plan for large-diameter multi-segment combined gears, and proposes a plan for first processing the petals separately and then assembling them into a full circle for fine processing. After semi-finishing, multiple arc segment tooth blocks are assembled into half gears, and two small semi-circular half-shaped gears with weaker rigidity are assembled into a large gear through tooling for fine processing, avoiding deformation of the arc segment tooth blocks during separate processing and installation errors during assembly. After processing, the part accuracy and assembly requirements of the drawing can be achieved.

[0016] The present invention provides a method for rough machining and semi-finishing of the tooth profile of an arc segment gear block. A CNC gantry boring and milling machine is used in conjunction with a finger-shaped milling cutter to perform rough machining and semi-finishing on the arc segment gear block in steps. Aging treatment is interspersed in the middle to eliminate stress, and the gear is gradually reduced to approach the finished gear, thereby ensuring machining accuracy.

[0017] The present invention has developed a connecting tool to assemble two half-shaped gears into a full-circle large gear, changing the original unstable semi-circular structure into a full-circle structure. At the same time, the two assembled half-shaped gears are arranged symmetrically, which solves the problem of unbalanced load in the processing process. The processing process is smooth and the processing accuracy is guaranteed. In addition, the two half-shaped gears are processed together, which effectively improves the processing efficiency.

[0018] The present invention also develops a special centering mechanism installed on the tool holder of the gear hobbing machine to ensure the accurate position of the disc milling cutter on the tool holder, so that the symmetrical center plane of the disc milling cutter passes through the rotation center of the processed gear, fully ensuring the processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the combined gear; Figure 2 It is a schematic diagram of a single arc segment tooth block; Figure 3This is a schematic diagram of the tooth groove benchmark for gantry milling rough machining; Figure 4 This is a schematic diagram of the tooth groove benchmark for semi-finishing machining by gantry milling; Figure 5 This is a schematic diagram of the boring machine table rotating to process tooth grooves; Figure 6 This is a schematic diagram of assembling a full circle gear; Figure 7 The schematic diagram of the connection tooling is shown in Figure 2. Figure 7 (a) is a partial view of the connection between the connecting fixture and the hub screw. Figure 7 (b) is a schematic diagram of the hole positions on the connection surface of the connection tooling; Figure 8 This is a diagram of using a special centering mechanism to align the disc milling cutter. Figure 8 (a) and Figure 8 (b) Schematic diagrams from different perspectives.

[0020] Reference numerals: 1. arc segment tooth block, 2. wheel hub, 3. center tooth groove, 4. allowance, 5. connecting tool, 6. tool holder, 7. base, 8. telescopic rod, 9. V-shaped positioning block, 10. disc milling cutter, 11 tool reference surface. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] The present invention provides a method for machining large-diameter multi-segment combined gears, which is mainly suitable for large-diameter multi-segment combined gears with a center angle of no more than 180°. The method adopts a method of first rough-machining and semi-finishing each tooth block individually, and then assembling them into a full-circle gear for fine machining. This method can overcome the deformation and assembly errors caused by individual machining.

[0023] In the following examples, combined Figure 1 Taking the large-diameter multi-segment combined gear shown in the figure as an example, the processing method of the present invention is described in detail. The combined gear in the figure is composed of 6 arc segment gear blocks 1 of the same length and a hub 2. The tooth profile of the arc segment gear block 1 is a standard straight tooth. The diameter of the gear is about φ16 meters and the gear accuracy is GB / T10095-8 level; Figure 2 The center of the length of each arc segment tooth block 1 is a tooth groove, that is, the center tooth groove 3 in the figure, and the two end surfaces of the length are half tooth grooves.

[0024] The processing method of the present invention is as follows: first, a high-precision CNC machining center is used in conjunction with a finger-shaped milling cutter to perform rough machining and semi-finishing on the arc segment tooth block 1 separately, and an aging treatment is arranged in the middle to eliminate stress. Then, multiple arc segment tooth blocks 1 are assembled into two half-shaped gears, and then the two half-shaped gears with weaker rigidity are assembled into a full-circle gear through a connecting tool 5. Finally, a large vertical lathe and a large hobbing machine are used for fine machining. After fine milling of the teeth, the gears are directly assembled. The specific process is as follows.

[0025] 1. Rough machining and semi-finishing of arc segment tooth profile 1.

[0026] 1) Rough machining of the tooth profile of arc segment 1.

[0027] Step 1: Rough machining of the arc segment gear segment 1.

[0028] On the CNC gantry boring and milling machine, program the rough machining of the thickness and length end large surfaces, inner and outer circle parts; then carry out the tempering process to ensure the hardness requirements of the drawing.

[0029] Step 2: Semi-finishing of the outer shape of the arc segment gear block 1.

[0030] On the CNC gantry boring and milling machine, program the semi-finishing machining of the thickness and length end surfaces, and the inner and outer circle parts.

[0031] Step 3: Milling the reference tooth groove of arc segment 1, such as Figure 3 .

[0032] On a CNC gantry boring and milling machine, the arc segment tooth block 1 center line and end face are aligned, leveled, and pressed. The machine tool uses the outer circle as a reference to find the part's rotation center, align both ends of the length, and use the length center tooth groove 3 as the 0-position tooth groove. The program is used to mill out the groove shape of each tooth, leaving an even allowance of 4 according to the allowance requirements, and a processing depth of 5mm. This is used as the reference groove shape to facilitate the boring machine's alignment and tool processing.

[0033] Step 4: Rough milling of tooth groove of arc segment 1, refer to Figure 5 .

[0034] Place arc-segment gear segment 1 flat on the boring machine's rotary table. In the figure, O1 represents the center of the gear, and O2 represents the center of the boring machine's rotary table. For ease of alignment, the part centerline and the rotary table centerline are aligned. Equipped with a finger milling cutter on the boring machine spindle, each tooth slot can be machined by aligning the center of each tooth slot with the spindle centerline by rotating the rotary table at angles θ, 2θ, 3θ, 4θ, 5θ, etc., combined with translation of the boring spindle. The angle θ of each tooth slot is 360° / Z, where Z represents the number of teeth in a full circle.

[0035] 2) Artificial aging after processing: enter the heat treatment furnace, control the heating temperature rise, holding time and cooling rate to eliminate processing stress.

[0036] 3) Semi-finishing of the tooth profile of arc segment gear block 1.

[0037] Step 1: semi-finishing of the outer shape of the arc segment gear block 1.

[0038] On the CNC gantry boring and milling machine, program the semi-finishing machining of the thickness and length end surfaces, and the inner and outer circle parts.

[0039] Step 2: Mill the reference tooth groove of arc segment 1, reference Figure 4 The method is the same as the third step of rough machining. On the CNC gantry boring and milling machine, the arc segment tooth block 1 center line and end face are aligned and leveled and pressed. The machine tool uses the outer circle as the reference to find the part rotation center, align the two ends of the length, and use the length center tooth groove 3 as the 0-position tooth groove. The program is used to mill out the groove shape of each tooth. According to the allowance requirements, a uniform allowance of 4 is left, and the processing depth is 5mm. This is used as the reference groove shape to facilitate the boring machine to align and process the tool.

[0040] Step 3: Semi-finish milling of tooth groove of arc segment 1, refer to Figure 5 The method is the same as in step 4 of roughing. Place arc segment 1 flat on the boring machine's rotary table. O1 is the center of the gear, and O2 is the center of the boring machine's rotary table. To facilitate alignment, align the part centerline with the rotary table centerline. Equip the boring machine spindle with a finger milling cutter. By rotating the rotary table at various angles (θ, 2θ, 3θ, 4θ, 5θ, etc.) and translating the boring spindle, each tooth slot can be machined to align its center with the spindle center. The included angle θ of each tooth slot is 360° / Z, where Z equals the number of teeth in the full circle.

[0041] 2. Assembly of arc segment tooth block 1.

[0042] After the semi-finishing is completed, multiple arc segment gear blocks 1 are Figure 1 The combined gears shown are assembled into half-gears (half-gears refer to assembled combined gears that have not yet completed tooth shape finishing and subsequent processes). Since the center angle of the half-gear is less than 180°, there is a deformation problem when processing it alone. At the same time, it is difficult to align and measure the semicircle during vertical lathe and gear hobbing machine processing. The off-load problem during processing will also cause large processing errors. The two half-gears combined by the arc segment gear block 1 and the hub 2 are a small semicircular symmetrical structure. When combined into a full circle, there are large gaps at two places at 180°, and they cannot be combined into a full circle. The diameter size cannot be measured during vertical lathe processing, and it cannot be clamped to the state of vertical lathe processing during gear hobbing machine processing, and the final gear accuracy cannot be met.

[0043] Therefore, the present invention designs the connection tool 5 before finishing, as Figure 6-7As shown, the gaps at both ends are filled with the help of the connecting tool 5, so that the two half-shaped gears are assembled into a full-circle gear, and the original unstable small semi-circle structure is changed into a full-circle structure. The two assembled half-shaped gears are arranged symmetrically, which solves the problem of unbalanced load in the turning and milling process. At the same time, the two pieces are processed together, the processing is smooth, it is convenient to measure and control the gear diameter size, ensure the processing accuracy, and improve the processing efficiency.

[0044] During assembly, the centers of the two half-shaped gears are aligned and the teeth are arranged symmetrically. The end faces on both sides are connected and fixed by connecting fixtures 5, as shown in FIG. Figure 6 As shown, if the center angle of the half gear is less than 180 degrees, two connecting fixtures 5 are respectively set in the gap between the end faces of the two half gears and connected to the hubs 2 on both sides by screws. The two connecting fixtures 5 are the same size and symmetrically arranged. The size of the connecting fixture 5 is designed to just fill the gap, so that the two half gears are assembled into a full-circle gear with symmetrical teeth. If the center angle of the half gear is equal to 180 degrees, the full-circle gear can be assembled by directly fixing the hubs 2 on both sides.

[0045] 3. Finishing of tooth profile of full circle gear.

[0046] The tooth profile finishing of full circle gears is carried out on large vertical lathes and large gear hobbing machines. After processing, the tooth profile is guaranteed to meet the accuracy requirements.

[0047] The present invention proposes a method for precision gear cutting using a disc milling cutter 10 on a large gear hobbing machine. Since the disc milling cutter 10 is usually used for rough machining of gear tooth profiles, in order to ensure high-precision gear machining (grade 8 accuracy) in the present invention, a special alignment scheme for the disc milling cutter 10 is designed to ensure gear machining accuracy.

[0048] In order to ensure that the position of the disc milling cutter 10 on the tool holder 6 is accurate, that is, to ensure that the symmetrical center plane of the disc milling cutter 10 passes through the rotation center of the processed gear, the present invention designs and manufactures a special centering mechanism and a disc milling cutter 10 with a tool reference surface 11, such as Figure 8As shown, a special centering mechanism is installed on the gear hobbing machine tool holder 6, which consists of a base 7, a telescopic rod 8 and a V-shaped positioning block 9, and a V-shaped tool reference surface 11 is made on the disc milling cutter 10 cutter body, and the angle of the tool reference surface 11 is consistent with the angle of the V-shaped positioning block 9; when in use, first align the center of the full circle gear with the center of the gear hobbing machine rotary table, then install the special centering mechanism at the set position on the gear hobbing machine tool holder 6, and then install the disc milling cutter 10, adjust the telescopic rod 8 so that the V-shaped positioning block 9 extends out and contacts the tool reference surface 11 of the disc milling cutter 10, use a feeler gauge to check the gap between the tool reference surface 11 of the disc milling cutter 10 and the two side surfaces of the V-shaped positioning block 9, adjust the position of the disc milling cutter 10 and check with a feeler gauge to make the gaps on both sides consistent, thereby determining that the symmetrical center plane of the disc milling cutter 10 passes through the rotation center of the full circle gear to ensure centering, and then perform fine gear milling.

[0049] In the above embodiment, the arc segment gear block 1 and the wheel hub 2 are assembled together during fine turning and fine milling, thereby avoiding deformation of the arc segment gear block 1 caused by separate processing and installation errors during assembly. After fine milling of the two half-shaped gears, the accuracy is tested online and reaches the level 8 accuracy requirement, meeting the design requirements and assembly requirements of the drawings.

[0050] The processing method of the present invention is described above in conjunction with specific embodiments, but the processing method of the present invention is not limited to processing Figure 1 The combined gear shown is also suitable for processing any other large-diameter multi-segment combined gears similar to the above-mentioned gear forms.

[0051] In general, the present invention provides a total solution for machining large-diameter multi-segment combined gears, which has the following characteristics: 1) First, process the petals separately, and then assemble them into a full circle for fine processing to avoid deformation during individual processing and assembly errors; 2) After the arc segment 1 is tempered, three outer contour machining and three gear cutting machining processes are performed alternately. The first gear cutting process has a 10mm allowance (single-block roughing tooth shape), the second gear cutting process has a 5mm allowance (single-block semi-finishing tooth shape), and the third machining process is completed (combined full-circle finishing tooth shape). The latter machining corrects the deformation of the previous machining and gradually removes the amount to approach the finishing size. Before finishing, the clamping claws are loosened to release stress to ensure the stability of the finishing size. 3) After the first tooth cutting, artificial aging treatment is arranged to eliminate internal stress; 4) After the second gear cutting process, the multiple arc segment gear segments 1 are assembled into two half-shaped gears, and the two half-shaped gears are assembled into a full-circle gear with symmetrical teeth through the connecting tool 5; 5) Fine turning and fine milling are performed on large vertical lathes and large gear hobbing machines.

[0052] The present invention also provides a method for rough machining and semi-finishing of the tooth profile of the arc segment tooth block 1, and innovates a method for centering, uniform allowance and deformation control of the tooth profile of the arc segment tooth block 1 using a boring and milling machine for rough machining; the full circle machining of the combined gear is achieved by connecting the tool 5, and the milling accuracy is ensured by a special centering mechanism, providing an efficient and high-precision machining method for the machining of large-diameter multi-segment combined gears. The method is proposed based on existing equipment and production capacity, and does not require equipment improvement or upgrading, thereby reducing production costs and improving production efficiency.

[0053] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for machining a large-diameter multi-segment combined gear, wherein the combined gear is composed of multiple arc-segment gears of the same length assembled through a hub, with a center angle of no more than 180 degrees, characterized in that: During processing, each arc segment tooth block is first rough-machined and semi-finished separately, and then the semi-finished arc segment tooth blocks are assembled into two half-shaped gears through the wheel hub, and the two half-shaped gears are assembled into a full-circle gear with symmetrical teeth using a connecting tool. Finally, the tooth shape of the full-circle gear is fine-machined to ensure that the tooth shape meets the design requirements.

2. A method for machining a large-diameter multi-segment combined gear according to claim 1, characterized in that: The rough machining of arc segment gear includes the following steps: (1) Rough machining of the arc segment gear block: On a CNC gantry boring and milling machine, rough machining is performed on the arc segment gear block's thickness, length end large surface, inner and outer circle parts, and then the tempering process is performed to ensure the hardness requirements of the drawing; (2) Semi-finishing of the arc segment gear block: On a CNC gantry boring and milling machine, semi-finish the thickness and length end surface, inner and outer circle parts of the arc segment gear block; (3) Milling the reference tooth groove of the arc segment tooth block: On the CNC gantry boring and milling machine, align and level the arc segment tooth block according to the center line and end face, and press it tightly. The machine tool uses the outer circle of the arc segment tooth block as the reference to find the center of rotation of the part, align the two ends of the length, and use the tooth groove at the center of the length as the 0-position tooth groove. Mill out the groove shape of each tooth and process it to a certain depth as the reference groove shape to facilitate the boring machine to align and process the tool; (4) Rough milling of the tooth groove with the arc segment tooth block. Place the arc segment tooth block flat on the rotary table of the boring machine, and align the center line of the part with the center line of the rotary table. Equip the spindle of the boring machine with a finger milling cutter, rotate the table according to the angle of each tooth groove, and combine the translation of the boring spindle to align the center of each tooth groove with the center of the spindle, and process each tooth groove.

3. A method for machining a large-diameter multi-segment combined gear according to claim 2, characterized in that: When the arc segment tooth block is used for rough milling of tooth grooves, the angle θ of each tooth groove is 360° / Z, where Z is the number of teeth in a full circle.

4. A method for machining a large-diameter multi-segment combined gear according to claim 2, characterized in that: The semi-finishing of the arc segment gear includes the following steps: (1) Semi-finishing of the arc segment gear block shape, including the thickness and length end large surface, inner and outer circle parts; (2) Semi-finish milling of the reference tooth groove of the arc segment tooth block, the method is the same as the rough machining step (3); (3) Semi-finish milling of the tooth groove of the arc segment tooth block, the method is the same as the rough machining step (4).

5. A method for machining a large-diameter multi-segment combined gear according to claim 4, characterized in that: Aging treatment is arranged between rough machining and semi-finishing to eliminate machining stress.

6. The method for machining a large-diameter multi-segment combined gear according to claim 1, characterized in that: The center angle of the half gear is the same as the center angle of the combined gear. When assembling the full circle gear, the centers of the two half gears are aligned and the teeth are arranged symmetrically. If the center angle of the half gear is less than 180 degrees, two connecting tools are set in the gap between the end faces of the two half gears and connected to the hubs on both sides respectively, and the two half gears are assembled into a full circle gear with symmetrical teeth. If the center angle of the half gear is equal to 180 degrees, the hubs on both sides can be directly fixed and connected to assemble the full circle gear.

7. A method for machining a large-diameter multi-segment combined gear according to claim 6, characterized in that: When the center angle of the half gear is less than 180 degrees, the two connecting tools are of the same size and symmetrically arranged. The size of the connecting tool is designed to just fill the gap, thereby assembling the two half gears into a full-circle gear with symmetrical teeth.

8. The method for machining a large-diameter multi-segment combined gear according to claim 1, characterized in that: The tooth profile finishing of full circle gears is carried out on large vertical lathes and large gear hobbing machines. After processing, the tooth profile is guaranteed to meet the accuracy requirements.

9. A method for machining a large-diameter multi-segment combined gear according to claim 8, characterized in that: When finishing full-circle gears, a special centering mechanism is used to ensure that the symmetrical center plane of the disc milling cutter passes through the rotation center of the gear being processed. The special centering mechanism includes a base, a telescopic rod and a V-shaped positioning block. The disc milling cutter is machined with a tool reference surface. When in use, first install the special centering mechanism on the gear hobbing machine tool holder, then install the disc milling cutter, adjust the telescopic rod so that the V-shaped positioning block extends out and contacts the tool reference surface of the disc milling cutter, use a feeler gauge to check the gap between the two sides of the disc milling cutter and the two sides of the V-shaped positioning block, adjust the position of the disc milling cutter so that the gaps on both sides are consistent, and then perform fine gear milling.

10. The method for machining a large-diameter multi-segment combined gear according to claim 1, characterized in that: The tooth shape of the arc segment tooth block is a standard straight tooth, the center of each arc segment length is a tooth groove, and the two end surfaces of the length are half tooth grooves.

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