A method for machining large-diameter multi-segment combined gears

Abstract

This invention relates to a method for machining large-diameter multi-segment combined gears, belonging to the field of combined gear machining technology. The machining process involves first roughing and semi-finishing the arc-segment gear blocks individually, with stress relief treatments interspersed throughout. Then, multiple arc-segment gear blocks are assembled into two half-gears, which are then assembled into a complete circular gear using connecting fixtures. Finally, a large vertical lathe and a large gear hobbing machine are used for finishing. After precision milling, the gears directly enter the assembly process, avoiding deformation caused by individual arc-segment gear block machining and installation errors during assembly. The finished product meets the part accuracy and assembly requirements, and effectively improves machining efficiency.

Description

Technical Field

[0001] This invention relates to the field of combined gear machining technology, and specifically to a method for machining large-diameter multi-segment combined gears. Background Technology

[0002] Multi-segment combined gears are a common structural form in transmission parts. They are generally composed of 6 to 12 arc-shaped tooth blocks of equal length and a hub, forming either a complete circle or a non-complete circle. The maximum diameter of the gear assembly can reach or exceed φ16 meters. The gear precision is GB / T10095-8 grade, and the tooth profile is generally standard spur tooth. The center of each arc-shaped tooth block is a tooth groove, and the two end faces of the length are half-tooth groove structures. A structural diagram is shown below. Figure 1 and Figure 2 As shown.

[0003] The machining of multi-segment combined gears can employ different methods depending on the combination method. Currently, most similar multi-segment combined gears with relatively small diameters (below φ10 meters) are machined segment by segment separately and then assembled for direct use. Each arc segment tooth block is precision-machined using a high-precision CNC machining center and specialized tools. This machining method eliminates the reliance on large vertical lathes and large gear hobbing machines, but it also has some problems. Due to the limitations of large precision equipment specifications, it is difficult to guarantee the machining accuracy and a certain degree of interchangeability of individual tooth blocks for ultra-large diameter (φ12-16 meters) multi-segment combined gears, which has a significant impact on product use. Therefore, we propose a new method for machining large-diameter multi-segment combined gears. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for machining large-diameter multi-segment combined gears, which can avoid the deformation and assembly errors caused by machining individual arc segment tooth blocks, and effectively ensure that the precision of the machined gears meets the requirements.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for machining large-diameter multi-segment combined gears, wherein the combined gears are composed of multiple arc-shaped tooth blocks of the same length assembled by a hub, with a central angle not exceeding 180 degrees. During machining, each arc-shaped tooth block is first rough-machined and semi-finished individually. Then, the semi-finished multiple arc-shaped tooth blocks are assembled into two half-gears by a hub, and the two half-gears are assembled into a complete circular gear with symmetrical teeth using a connecting fixture. Finally, the teeth of the complete circular gear are finished to meet the design requirements.

[0007] Furthermore, the rough machining of the arc segment tooth block includes the following steps:

[0008] (1) Rough machining of arc segment tooth block: On a CNC gantry milling machine, rough machining of the arc segment tooth block's outer thickness and length end face, inner and outer circles, and then heat treatment process to ensure the hardness requirements of the drawing.

[0009] (2) Semi-finishing of the arc segment tooth block: On a CNC gantry milling machine, the outer thickness and length of the arc segment tooth block, as well as the inner and outer circles, are semi-finished.

[0010] (3) Milling reference tooth grooves for arc segment tooth blocks: On a CNC gantry milling machine, align and flatten 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 rotation center of the part, align the two ends of the length, and use the tooth groove at the length center as the 0 position tooth groove to mill the groove shape of each tooth. A certain depth is machined as the reference groove shape, which is convenient for the boring machine to align and perform tool setting.

[0011] (4) Rough milling of the tooth grooves of 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 in a parallel state; the spindle of the boring machine is equipped with a finger end mill, and the rotary table is rotated according to the included angle of each tooth groove. Combined with the translation of the boring spindle, the center of each tooth groove is aligned with the center of the spindle, and each tooth groove is machined.

[0012] Furthermore, when rough milling the tooth grooves of the arc segment tooth block, the included angle θ of each tooth groove is 360° / Z, where Z is the number of teeth in the whole circle.

[0013] Furthermore, the semi-finishing of the arc-shaped tooth block includes the following steps:

[0014] (1) Semi-finishing of the arc segment tooth block, including the thickness and length of the large surface and the inner and outer circles;

[0015] (2) Semi-finish mill the reference tooth groove of the arc segment tooth block, using the same method as step (3) of rough machining;

[0016] (3) The arc segment tooth block is semi-finish milled with the tooth groove, the method is the same as the rough machining step (4).

[0017] Furthermore, aging treatments are interspersed between roughing and semi-finishing to eliminate machining stress.

[0018] Furthermore, the center angle of the semi-gear is the same as that of the combined gear. When assembling the complete circular gear, the centers of the two semi-gears are coincident and the teeth are arranged symmetrically. If the center angle of the semi-gear is less than 180 degrees, two connecting fixtures are set at the gap between the end faces of the two semi-gears and connected to the hubs on both sides respectively. The two semi-gears are assembled into a complete circular gear with symmetrical teeth. If the center angle of the semi-gear is equal to 180 degrees, the hubs on both sides can be directly fixedly connected to assemble the complete circular gear.

[0019] Furthermore, when the center angle of the semi-gear is less than 180 degrees, the two connecting fixtures are the same size and arranged symmetrically. The size of the connecting fixtures is designed to just fill the gap, thereby assembling the two semi-gears into a complete round gear with symmetrical teeth.

[0020] Furthermore, the tooth profile of the complete circular gear is precision machined on a large vertical lathe and a large gear hobbing machine, ensuring that the tooth profile meets the accuracy requirements after machining.

[0021] Furthermore, when finishing a round gear, a dedicated 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 machined. The dedicated centering mechanism includes a base, a telescopic rod, and a V-shaped positioning block. The disc milling cutter has a tool setting reference surface machined on it. In use, the dedicated centering mechanism is first installed on the hobbing machine tool holder, and then the disc milling cutter is installed. The telescopic rod is adjusted so that the V-shaped positioning block extends out and contacts the tool setting reference surface of the disc milling cutter. A feeler gauge is used to check the gap between the two sides of the disc milling cutter and the two sides of the V-shaped positioning block. After adjusting the position of the disc milling cutter to make the gap on both sides consistent, the gear is then finished milled.

[0022] Furthermore, the tooth profile of the arc segment tooth block is a standard straight tooth, with the center of each arc segment being a tooth groove and the two end faces of the length being half tooth grooves.

[0023] Beneficial effects: The processing method of this invention provides a complete processing scheme for large-diameter multi-segment combined gears. It proposes a scheme of processing the segments separately and then assembling them into a whole circle for precision machining. After semi-finishing, multiple arc-segment tooth blocks are assembled into a semi-shaped gear, and two small semi-circular semi-shaped gears with weaker rigidity are connected by tooling and assembled into a large gear for precision machining. This avoids the deformation caused by processing the arc-segment tooth blocks separately and the installation errors during assembly. After processing, the part accuracy and assembly requirements of the drawings can be achieved.

[0024] This invention provides a method for roughing and semi-finishing the tooth profile of an arc segment gear block. By using a CNC gantry milling machine with a finger milling cutter, the arc segment gear block is roughed and semi-finished in stages, with aging treatment interspersed to eliminate stress, gradually reducing the amount of material to approach the finished gear, thus ensuring machining accuracy.

[0025] This invention develops a connecting fixture that assembles two semi-circular gears into a large circular gear, transforming the original unstable semi-circular structure into a full-circular structure. The two assembled semi-circular gears are symmetrically arranged, solving the problem of eccentric loading during processing. The processing is stable, ensuring processing accuracy. Furthermore, the simultaneous processing of the two semi-circular gears effectively improves processing efficiency.

[0026] This invention also developed a special centering mechanism installed on the hobbing machine tool holder 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 gear being machined, thus fully guaranteeing the machining accuracy. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a combined gear.

[0028] Figure 2 A schematic diagram of a single arc segment tooth block;

[0029] Figure 3 This is a schematic diagram of the datum for rough machining of tooth grooves in a gantry milling machine.

[0030] Figure 4 This is a schematic diagram of the datum for semi-finishing of tooth grooves in a gantry milling machine.

[0031] Figure 5 A schematic diagram of a boring machine's worktable rotating to machine gear grooves;

[0032] Figure 6 This is a schematic diagram of assembling a complete circular gear;

[0033] Figure 7 This is a schematic diagram of the connection tooling. Figure 7 (a) is a partial view of the connection between the tooling and the hub bolts. Figure 7 (b) is a schematic diagram of the holes on the connecting surface of the connecting tool;

[0034] Figure 8 A schematic diagram illustrating the alignment of the disc milling cutter using a dedicated alignment mechanism. Figure 8 (a) and Figure 8 (b) are schematic diagrams from different perspectives.

[0035] Reference numerals in the attached drawings: 1. Arc-shaped tooth block, 2. Hub, 3. Center tooth groove, 4. Allowance, 5. Connecting fixture, 6. Tool holder, 7. Base, 8. Telescopic rod, 9. V-shaped positioning block, 10. Disc milling cutter, 11. Tool setting reference surface. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0037] This invention provides a machining method for large-diameter multi-segment combined gears, which is mainly applicable to large-diameter multi-segment combined gears with a center angle of no more than 180°. The method adopts the approach of first roughing and semi-finishing each tooth block separately, and then assembling them into a whole round gear for finishing, which can overcome the deformation and assembly errors caused by individual machining.

[0038] In the following embodiments, combined with Figure 1 Taking the large-diameter multi-segment combined gear shown as an example, the processing method of the present invention will be described in detail. The combined gear in the figure is composed of six arc-shaped tooth blocks 1 of the same length and a hub 2, etc. The tooth profile of the arc-shaped tooth blocks 1 is a standard spur tooth. The diameter of the gear is approximately φ16 meters, and the gear accuracy is GB / T10095-8 grade; Figure 2The center of the length of each arc segment tooth block 1 is the tooth groove, that is, the center tooth groove 3 in the figure, and the two ends of the length are half tooth grooves.

[0039] The processing method of the present invention is as follows: First, a high-precision CNC machining center is used in conjunction with a finger milling cutter to perform roughing and semi-finishing of the arc segment tooth block 1 separately, with aging treatment arranged in between to eliminate stress. Then, multiple arc segment tooth blocks 1 are assembled into two half-gears. The two half-gears with weaker rigidity are then assembled into a complete round gear through a connecting fixture 5. Finally, a large vertical lathe and a large gear hobbing machine are used for finishing. After finishing the gears, the gears are directly put into assembly. The specific process is as follows.

[0040] 1. Roughing and semi-finishing of the tooth profile of the arc segment tooth block 1.

[0041] 1) Rough machining of the tooth profile of arc segment tooth block 1.

[0042] Step 1: Rough machining of the outer shape of arc segment tooth block 1.

[0043] On a CNC gantry milling machine, a program is written to rough machine the outer thickness and length of the large surface, as well as the inner and outer circles; then a heat treatment process is performed to ensure the hardness requirements of the drawing are met.

[0044] Step 2: Semi-finishing of the outer shape of arc segment tooth block 1.

[0045] On a CNC gantry milling machine, a program is written to perform semi-finishing of the outer surface, including the thickness and length of the outer diameter, as well as the inner and outer circles.

[0046] Step 3: Mill the reference tooth groove for arc segment tooth block 1, as follows: Figure 3 .

[0047] On a CNC gantry milling machine, the center line and end face of the arc segment tooth block 1 are aligned, leveled, and pressed. The outer circle of the machine tool is used as a reference to find the rotation center of the part. The two ends of the length are aligned. The length center tooth groove 3 is used as the 0 position tooth groove. The program is programmed to mill the groove shape of each tooth. The allowance 4 is left evenly according to the allowance requirements. The machining depth is 5mm, which serves as the reference groove shape to facilitate the alignment and tool setting of the boring machine.

[0048] Step 4: Rough mill the tooth grooves of arc segment tooth block 1, refer to... Figure 5 .

[0049] Place the arc-shaped gear block 1 flat on the rotary table of the boring machine. In the figure, O1 is the center of the gear, and O2 is the center of the rotary table. For easy alignment, the center line of the part is aligned parallel to the center line of the rotary table. The boring machine spindle is equipped with a finger end mill. By using the rotary table angles θ, 2θ, 3θ, 4θ, 5θ... and combining the translation of the boring spindle, the center of each tooth groove is aligned with the center of the spindle to machine each tooth groove. The included angle θ of each tooth groove is 360° / Z, where Z represents the number of teeth in the circle.

[0050] 2) Artificial aging after processing: The material is placed in a heat treatment furnace, and the heating temperature rise, holding time and cooling rate are controlled to eliminate processing stress.

[0051] 3) Semi-finishing of the tooth profile of arc segment tooth block 1.

[0052] Step 1: Semi-finishing of the outer shape of arc segment tooth block 1.

[0053] On a CNC gantry milling machine, a program is written to perform semi-finishing of the outer surface, including the thickness and length of the outer diameter, as well as the inner and outer circles.

[0054] Step 2: Mill the reference tooth groove for arc segment tooth block 1, refer to... Figure 4 The method is the same as the third step of rough machining. On the CNC gantry boring and milling machine, align and flatten the arc segment tooth block 1 according to the center line and end face, and press it tightly. Use the outer circle of the machine tool as the reference to find the rotation center of the part. Align the two ends of the length. Use the length center tooth groove 3 as the 0 position tooth groove. Write a program to mill the groove shape of each tooth. Leave a uniform allowance 4 according to the allowance requirements. The machining depth is 5mm, which serves as the reference groove shape to facilitate the boring machine alignment and tool setting.

[0055] Step 3: Finish mill the tooth grooves of arc segment tooth block 1 (see reference). Figure 5 The method is the same as the fourth step of rough machining. Place the arc-shaped tooth block 1 flat on the rotary table of the boring machine. O1 is the center of the gear, and O2 is the center of the rotary table. To facilitate alignment of the part's center line with the rotary table's center line, ensure they are parallel. The boring machine spindle is equipped with a finger end mill. By adjusting the rotary table angles θ, 2θ, 3θ, 4θ, 5θ... and combining this with the translation of the boring spindle, align the center of each tooth groove with the spindle center to machine each tooth groove. The included angle θ of each tooth groove is 360° / Z, where Z is the number of teeth in the circle.

[0056] II. Assembly of Arc Segment Tooth Block 1

[0057] After semi-finishing, multiple arc-segment tooth blocks 1 are arranged according to... Figure 1 The combined gears shown are assembled into semi-gears (semi-gears refer to the assembled combined gears that have not yet completed tooth profile finishing and subsequent processes). Since the center angle of the semi-gear is less than 180°, there is a deformation problem when it is processed alone. At the same time, it is difficult to align and measure the semi-circle when it is processed on a vertical lathe and a gear hobbing machine. The off-center load during processing will also cause a large processing error. The two semi-gears combined with the arc segment tooth block 1 and the hub 2 are small semi-circular symmetrical structures. When they are combined into a complete circle, there are large gaps at 180°, which makes it impossible to combine them into a complete circle. The diameter dimension cannot be measured when processing on a vertical lathe, and it cannot be clamped into the state of processing on a gear hobbing machine, which cannot meet the final gear accuracy.

[0058] Therefore, the present invention designs a connecting fixture 5 before finishing, such as... Figure 6-7As shown, the gaps at both ends are filled with the help of the connecting fixture 5, so that the two half-gears are assembled into a whole round gear, and the original unstable small half-circle structure is transformed into a whole round structure. The two assembled half-gears are symmetrically arranged, which solves the problem of off-center load in the turning and milling process. At the same time, the two are processed together, the processing process is stable, it is easy to measure and control the gear diameter, ensures the processing accuracy, and improves the processing efficiency.

[0059] During assembly, the centers of the two semi-gears are aligned and their teeth are arranged symmetrically. The end faces on both sides are connected and fixed together by connecting fixture 5. Figure 6 As shown, if the center angle of the semi-gear is less than 180°, two connecting fixtures 5 are respectively set in the gap between the end faces of the two semi-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 fixtures 5 is designed to just fill the gap, so that the two semi-gears are assembled into a complete round gear with symmetrical teeth. If the center angle of the semi-gear is equal to 180 degrees, the hubs 2 on both sides can be directly fixedly connected to assemble into a complete round gear.

[0060] III. Precision machining of the tooth profile of the round gear.

[0061] The tooth profile of the round gear is precision machined on a large vertical lathe and a large gear hobbing machine. After machining, the tooth profile is guaranteed to meet the accuracy requirements.

[0062] This invention proposes a machining 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 teeth, a special alignment scheme for the disc milling cutter 10 is designed to ensure high-precision gear machining (level 8 accuracy) in this invention, thus guaranteeing gear machining accuracy.

[0063] To ensure the accurate positioning of the disc milling cutter 10 on the tool holder 6, that is, to ensure that the symmetrical center plane of the disc milling cutter 10 passes through the rotation center of the gear being machined, this invention designs and manufactures a disc milling cutter 10 with a dedicated centering mechanism and a tool setting reference surface 11, as follows: Figure 8As shown, a dedicated centering mechanism is installed on the hobbing machine tool holder 6. This dedicated centering mechanism consists of a base 7, a telescopic rod 8, and a V-shaped positioning block 9. A V-shaped tool setting reference surface 11 is made on the disc milling cutter 10, and the included angle of the tool setting reference surface 11 is consistent with the included angle of the V-shaped positioning block 9. In use, first align the center of the circular gear with the center of the hobbing machine's rotary table. Then, install the dedicated centering mechanism at the set position on the 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 and contacts the tool setting reference surface 11 of the disc milling cutter 10. Use a feeler gauge to check the gap between the tool setting reference surface 11 of the disc milling cutter 10 and the two sides of the V-shaped positioning block 9. Adjust the position of the disc milling cutter 10 and use a feeler gauge to check that the gaps on both sides are consistent, thereby determining that the symmetrical center plane of the disc milling cutter 10 passes through the rotation center of the circular gear, ensuring centering, and then perform fine milling.

[0064] In the above embodiments, the arc segment tooth block 1 and the hub 2 are assembled together during precision turning and precision milling, which avoids the deformation of the arc segment tooth block 1 during separate processing and the installation error during assembly. After the two half-gears are precision milled, the accuracy is tested online and reaches the level 8 accuracy requirement, which meets the design requirements and assembly requirements of the drawings.

[0065] The processing method of the present invention has been described above with reference to specific embodiments, but the processing method of the present invention is not limited to processing. Figure 1 The combined gear shown is also applicable to the machining of any other large-diameter, multi-segment combined gears similar in form to the gear described above.

[0066] In summary, this invention provides a complete solution for machining large-diameter, multi-segment combined gears, which has the following characteristics:

[0067] 1) First, process the segments separately, then assemble them into a whole circle for precision machining to avoid deformation from individual processing and assembly errors;

[0068] 2) After heat treatment of arc segment 1, three outer contour machining and three tooth cutting machining are carried out alternately. The first tooth cutting machining leaves a margin of 10mm (single block rough machining tooth shape), the second tooth cutting machining leaves a margin of 5mm (single block semi-finish machining tooth shape), and the third machining is to form (combined whole circle finish machining tooth shape); the last machining corrects the deformation of the previous machining, gradually reducing the amount of material to approach the finish machining size. Before finish machining, the chuck is loosened to release stress and ensure the stability of the finish machining size;

[0069] 3) After the first tooth cutting, arrange artificial aging treatment to eliminate internal stress;

[0070] 4) After the second gear cutting process, multiple arc segment tooth blocks 1 are assembled into two half-gears, and the two half-gears are assembled into a complete round gear with symmetrical teeth through the connecting tool 5.

[0071] 5) Perform precision turning and precision milling on large vertical lathes and large gear hobbing machines.

[0072] This invention also provides a method for roughing and semi-finishing the tooth profile of the arc segment tooth block 1. It innovates the method of using a boring and milling machine to rough-machine the tooth profile of the arc segment tooth block 1, centering the tooth profile, uniformly leaving allowance, and controlling deformation. The combined gear is machined into a complete circle by connecting tooling 5, and the milling accuracy is ensured by a dedicated centering mechanism. This provides an efficient and high-precision machining method for the machining of large-diameter multi-segment combined gears. Moreover, it is proposed based on existing equipment and production capacity, without the need to improve or upgrade equipment, thereby reducing production costs and improving production efficiency.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope 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-shaped tooth blocks of equal length assembled by a hub, with a central angle not exceeding 180 degrees, characterized in that... During processing, each arc segment tooth block is first roughed and semi-finished individually. Then, the semi-finished multiple arc segment tooth blocks are assembled into two half-gears through a hub. The center angle of the half-gear is the same as that of the combined gear. When assembling the complete circular gear, the centers of the two half-gears are coincident and the teeth are arranged symmetrically. If the center angle of the half-gear is less than 180 degrees, two connecting fixtures are set at the gap between the end faces of the two half-gears and connected to the hubs on both sides respectively. The two half-gears are assembled into a complete circular 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 into a complete circular gear. Finally, the tooth profile of the complete circular gear is finished to meet the design requirements. The rough machining of the arc segment tooth block includes the following steps: (1) Rough machining of arc segment tooth block: On a CNC gantry milling machine, rough machining of the arc segment tooth block's outer thickness and length end face, inner and outer circles, and then heat treatment process to ensure the hardness requirements of the drawing. (2) Semi-finishing of the arc segment tooth block: On a CNC gantry milling machine, the outer thickness and length of the arc segment tooth block, as well as the inner and outer circles, are semi-finished. (3) Milling reference tooth grooves for arc segment tooth blocks: On a CNC gantry milling machine, align and flatten 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 rotation center of the part, align the two ends of the length, and use the tooth groove at the length center as the 0 position tooth groove to mill the groove shape of each tooth. A certain depth is machined as the reference groove shape, which is convenient for the boring machine to align and perform tool setting. (4) Rough milling of the tooth grooves of 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 in a parallel state; The spindle of the boring machine is equipped with a finger end mill, and the rotary table is rotated according to the included angle of each tooth groove. Combined with the translation of the boring spindle, the center of each tooth groove is aligned with the center of the spindle, and each tooth groove is machined. The semi-finishing of the arc segment tooth block includes the following steps: (1) Semi-finishing of the arc segment tooth block, including the thickness and length of the large surface and the inner and outer circles; (2) Semi-finish mill the reference tooth groove of the arc segment tooth block, using the same method as step (3) of rough machining; (3) The arc segment tooth block is semi-finish milled with the tooth groove, the method is the same as the rough machining step (4).

2. The method for machining large-diameter multi-segment combined gears according to claim 1, characterized in that, When rough milling the tooth grooves of the arc segment tooth block, the included angle θ of each tooth groove is 360° / Z, where Z is the number of teeth in the circle.

3. The method for machining a large-diameter multi-segment combined gear according to claim 1, characterized in that, Aging treatments are interspersed between roughing and semi-finishing processes to eliminate machining stress.

4. The method for machining a large-diameter multi-segment combined gear according to claim 1, characterized in that, When the center angle of the semi-gear is less than 180 degrees, the two connecting fixtures are the same size and arranged symmetrically. The size of the connecting fixtures is designed to just fill the gap, so that the two semi-gears can be assembled into a complete round gear with symmetrical teeth.

5. The method for machining a large-diameter multi-segment combined gear according to claim 1, characterized in that, The tooth profile of the round gear is precision machined on a large vertical lathe and a large gear hobbing machine. After machining, the tooth profile is guaranteed to meet the accuracy requirements.

6. The method for machining a large-diameter multi-segment combined gear according to claim 5, characterized in that, When finishing a round 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 machined. The special centering mechanism includes a base, a telescopic rod, and a V-shaped positioning block. The disc milling cutter has a tool setting reference surface. In use, the special centering mechanism is first installed on the hobbing machine tool holder, and then the disc milling cutter is installed. The telescopic rod is adjusted so that the V-shaped positioning block extends out and contacts the tool setting reference surface of the disc milling cutter. A feeler gauge is used to check the gap between the two sides of the disc milling cutter and the two sides of the V-shaped positioning block. After adjusting the position of the disc milling cutter to make the gap on both sides consistent, the gear is then finished milled.

7. The method for machining a large-diameter multi-segment combined gear according to claim 1, characterized in that, The tooth profile of the arc segment tooth block is a standard straight tooth, with a tooth groove at the center of each arc segment and half tooth grooves at both ends of the length.

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