A forming machining process of a sector hole main reduction gear

Abstract

The present application relates to the technical field of metal plastic forming, in particular to a forming machining process of a fan-shaped hole main reduction gear, comprising raw material inspection, blanking, chamfering, hot forging forming, normalizing treatment, shot blasting treatment, surface cleaning and lubrication and cold extrusion finishing, the present application focuses on the bottleneck of the fan-shaped groove machining technology of the motor main reduction gear, initiates the fan-shaped groove bottom bevel configuration, hot forging and finishing integrated near-net forming technology, realizes the double innovation breakthrough of structure and process, the bevel design reduces the one-side height of the die tooth part, improves the die tooth part strength, alleviates the stress concentration and thermal fatigue damage in the die hot forging process from the root, cooperates with the surface strengthening treatment of special die steel, and the die life is improved.

Description

Technical Field

[0001] This invention relates to the field of metal plastic forming technology, specifically to a forming process for a fan-shaped hole main reduction gear. Background Technology

[0002] The main reduction gear of the electric motor is a key load-bearing component of the power shift module of the new generation EDCT electric dual-clutch transmission. It needs to withstand the instantaneous peak torque impact of the hybrid system for a long time, cope with the high-frequency torque fluctuations caused by the switching between the engine and the electric motor, and at the same time meet the stringent NVH performance requirements of the vehicle, as well as the structural strength constraints imposed by the lightweight design. However, the traditional machining process for the sector hole of the main reduction gear of the electric motor generally adopts drilling and milling or full machining solutions, which have many technical pain points.

[0003] First, material utilization is low, with a large amount of metal wasted during the cutting process, significantly increasing manufacturing costs. Second, cutting disrupts the continuous flow lines within the metal, resulting in insufficient gear rigidity and fatigue strength, making it difficult to adapt to the complex stress environment of hybrid operation and prone to wear and deformation failure. Third, the product processing cycle is long, with multiple processes such as drilling and milling overlapping, severely reducing production efficiency. In summary, traditional processes cannot meet the performance, cost, and mass production requirements of the main reduction gear in motors. There is an urgent need to develop an innovative forging process for metal forming to simultaneously improve material utilization, mechanical properties, and processing efficiency, breaking through the technological bottlenecks. Summary of the Invention

[0004] The purpose of this invention is to provide a forming process for a sector-shaped bore main reduction gear to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a forming process for a sector-shaped bore main reduction gear, comprising the following steps:

[0006] Step 1: Inspect raw materials and select materials with specified strength and hardness;

[0007] Step 2: Material preparation. Cut the raw materials into blanks of the required size and weight according to the design requirements.

[0008] Step 3: Chamfer to remove sharp edges and burrs;

[0009] Step 4: Hot forging. The hot forging machine performs plastic deformation processing on the gear blank above the metal crystallization temperature, so that it is formed into the required tooth shape and geometry in the forging die. This is a near-net-shape forming process.

[0010] Step 5: Normalizing treatment, a pre-heat treatment to improve the machinability of the material, refine the grains, and eliminate internal stress;

[0011] Step Six: Shot blasting, a surface treatment that uses high-speed shot to impact the gear surface to achieve both cleaning and strengthening purposes;

[0012] Step 7: Surface cleaning and lubrication to remove oil, cutting fluid and metal shavings from the gear surface;

[0013] Step 8: Cold extrusion finishing. At room temperature, pressure is applied to the formed gear through a mold to cause it to undergo slight plastic deformation.

[0014] The fan-shaped groove bottom on the hot forging prepared in step four is designed with a sloping structure. Combined with the precise design of the mold cavity and the closed-loop control of the billet temperature, the fan-shaped groove structure is directly forged. The sloping design reduces the height of the mold teeth on one side.

[0015] The cold extrusion finishing process in step eight achieves the calibration of dimensions, control of the diameter tolerance of the sector groove, and control of the groove position accuracy, eliminating the cumulative error of accuracy caused by multiple clamping.

[0016] The hot forging machine tool in step four includes a machine plate frame, a row of variable force piles fixed below the machine plate frame, and a tensioning device installed on one side of the machine plate frame. The bottom end of the variable force pile is connected to a cover mold, which lowers to cooperate with the stationary base mold to impact the forging.

[0017] The variable force pile driver includes a pile column fixed on the machine plate frame, a pile plate fixed at the bottom end of the pile column, multiple foot column devices arranged around the pile plate, a brake for positioning the foot column devices, a pressure device for driving the brake, and a switch for releasing the pressure device.

[0018] During the pressing and impacting process of the die, the foot column device applies a flexible thrust to the die and a rigid thrust at the end of the pressing.

[0019] The tensioning device includes a chain frame fixed on the machine plate frame, an irregular chain with upper limit support on the chain frame, a row of curved columns fixed on the chain frame, and a traction component installed on the irregular chain. The traction component with arc movement deforms and expands under the push of the curved columns, and the deformed and expanded traction component pushes the pressure tool to reset.

[0020] The traction component includes a traveling seat fixed on the irregular chain, a pusher that slides directionally on the traveling seat, and a pusher spring for pushing the pusher to reset. The pusher is pushed by an upturned arc column encountered during transport.

[0021] The foot post device includes a column that slides through a through hole in the pile plate, a spring sleeved on the column, a frosted plate and a limiting block fixed at the top of the column, and the bottom of the column is fixedly connected to the cover mold.

[0022] The brake includes a positioning frame fixed on the pile, a support shaft and a booster shaft simultaneously supported on the positioning frame, a worm gear fixed on the booster shaft for meshing transmission, and a rubber scroll plate fixed at the end of the booster shaft. The worm gear is mounted on the positioning frame, and the worm gear and the support shaft establish transmission. The outer wall of the rotating rubber scroll plate gradually adheres to the abrasive plate, thereby positioning the abrasive plate through contact.

[0023] The pressure device includes an annular spring fixedly sleeved on the outside of the pile, an outer gear ring fixedly sleeved on the outside of the annular spring, and a power storage rod fixed on the outside of the outer gear ring. A fixed ring plate on the outer gear ring is used to engage with an annular groove opened on the outer side wall of the pile. The pusher is used to push the encountered power storage rod to reset. A fixed gear on the support shaft meshes with the outer gear ring for transmission.

[0024] The switch includes a subframe fixed to the pile, a pressure column that slides longitudinally on the subframe, a blocking body that slides laterally on the subframe, an output shaft that drives between the pressure column and the blocking body, and a C-shaped spring for pushing the pressure column to reset. The blocking body unidirectionally intercepts the reset energy storage rod, and the pressure column is used to detect the height of the cover mold.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. This invention focuses on the bottleneck of the processing technology of the sector groove of the main reduction gear of the motor, and pioneers the near-net-shape forming technology of the inclined surface configuration of the sector groove bottom, hot forging and finishing, achieving a dual breakthrough in structure and process innovation.

[0027] 2. This inclined surface design reduces the height of one side of the die teeth, improves the strength of the die teeth, and fundamentally alleviates stress concentration and thermal fatigue damage during the hot forging process. Combined with the surface strengthening treatment of special die steel, the die life is extended, significantly reducing the frequency of die replacement and maintenance investment. The cold extrusion finishing process accurately controls the size of the forgings, achieving high-precision control of the diameter tolerance and position of the fan-shaped groove. Hot forging ensures the continuity of metal flow lines, improves fatigue strength, and is suitable for peak torque impact and high-frequency start-stop conditions of hybrid systems.

[0028] 3. This process significantly reduces machining allowance and lowers raw material loss rate; by simplifying multiple cutting processes such as milling and drilling, production time is reduced, and the overall cost of mass production is significantly reduced, which can stably support customer capacity demand and provide a new technical paradigm for the efficient and low-cost manufacturing of similar complex forgings. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the present invention.

[0030] Figure 2 This is a schematic diagram of the variable force pile device.

[0031] Figure 3This is a schematic diagram showing the location of the pressure mold.

[0032] Figure 4 This is a schematic diagram of the tensioning device.

[0033] Figure 5 This is a schematic diagram of the traction component structure.

[0034] Figure 6 This is a schematic diagram showing the location of the pressure fixture.

[0035] Figure 7 This is a schematic diagram of the foot column device.

[0036] Figure 8 This is a schematic diagram of the brake mechanism.

[0037] Figure 9 This is a schematic diagram of the pressure fixture structure.

[0038] Figure 10 This is a schematic diagram of a rubber vortex plate structure.

[0039] In the diagram: 1. Machine plate frame; 2. Forging; 3. Variable force pile device; 4. Tensioning device; 5. Cover pressure mold; 6. Pressure tool; 7. Pile column; 8. Pile plate; 9. Foot column device; 10. Switch; 11. Brake; 12. Towing component; 13. Chain frame; 14. Irregular chain; 15. Curved arc column; 16. Push column body; 17. Traveling seat; 18. Back push spring; 19. Frosted plate; 20. Column tube; 21. Limiting block; 22. Spring; 23. Support shaft; 24. Worm gear; 25. Rubber scroll plate; 26. Pressure boosting shaft; 27. Positioning frame; 28. Power storage bar; 29. ​​External gear ring; 30. Ring spring; 31. Blocking body; 32. Lead-out shaft; 33. Pressing column; 34. Sub-frame; 35. C-type spring. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the technical solutions of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Please see Figures 1 to 10 This invention provides a technical solution: a forming process for a sector-shaped bore main reduction gear, comprising the following steps:

[0042] Step 1: Inspect raw materials and select materials with specified strength and hardness;

[0043] Step 2: Material preparation. Cut the raw materials into blanks of the required size and weight according to the design requirements.

[0044] Step 3: Chamfer to remove sharp edges and burrs;

[0045] Step 4: Hot forging. The hot forging machine performs plastic deformation processing on the gear blank above the metal crystallization temperature, so that it is formed into the required tooth shape and geometry in the forging die. This is a near-net-shape forming process.

[0046] Step 5: Normalizing treatment, a pre-heat treatment to improve the machinability of the material, refine the grains, and eliminate internal stress;

[0047] Step Six: Shot blasting, a surface treatment that uses high-speed shot to impact the gear surface to achieve both cleaning and strengthening purposes;

[0048] Step 7: Surface cleaning and lubrication to remove oil, cutting fluid and metal shavings from the gear surface;

[0049] Step 8: Cold extrusion finishing. At room temperature, pressure is applied to the formed gear through a mold to cause it to undergo slight plastic deformation.

[0050] The fan-shaped groove bottom on the hot forging prepared in step four is designed as a sloping structure. Combined with the precise design of the mold cavity and the closed-loop control of the billet temperature, the fan-shaped groove structure is directly forged. The sloping design reduces the height of the mold teeth on one side.

[0051] The cold extrusion finishing process in step eight achieves the control of calibration dimensions, sector groove diameter tolerance, and groove position accuracy, eliminating the cumulative accuracy error caused by multiple clamping.

[0052] This invention addresses the pain points in machining the sector groove of the main reduction gear in motors by innovatively employing an integrated hot forging and cold extrusion finishing process. The core breakthrough lies in the 22-degree inclined surface design of the sector groove bottom in the hot forging, combined with precise die cavity design and closed-loop temperature control of the billet. This not only directly forges the sector groove structure but also reduces the height of the die teeth on one side by more than 20% through the inclined surface design, improving the strength of the die teeth, preventing tooth breakage, and increasing the lifespan of the hot forging die by more than 80%. This completely eliminates the traditional drilling and milling machining method. After dimensional calibration through the cold extrusion finishing process, the sector groove diameter tolerance is stably controlled within ±0.1mm, and the groove position accuracy reaches 0.15mm. The forging precision directly meets the benchmark requirements for subsequent finishing, eliminating the cumulative accuracy errors caused by multiple clamping operations from the source, achieving a leapfrog upgrade of the sector groove from cutting forming to near-net-shape forging forming.

[0053] In terms of material utilization, this process eliminates the need for machining the inner surface of the fan-shaped groove after forging, increasing material utilization from 40-50% in traditional processes to 50-60%. This reduces material consumption per piece by over 10%, significantly decreasing metal cutting waste and directly lowering raw material costs. Simultaneously, the inclined bottom structure of the large-diameter groove of the motor main reduction gear reduces metal flow resistance during forging, improving forming and filling effects, further reducing scrap rates, and indirectly optimizing production costs. The increased mold life significantly reduces mold manufacturing costs and replacement frequency, lowering the risk of production interruptions and further compressing overall production costs.

[0054] From a mechanical performance perspective, the hot forging process ensures that the metal flow lines are continuously distributed along the contour of the fan-shaped groove, avoiding the cutting and damage to the metal fibers caused by machining. This enhances fatigue strength and significantly improves impact and deformation resistance, making it well-suited for the complex operating conditions of hybrid systems, including instantaneous peak torque impacts and high-frequency start-stop cycles, effectively extending product service life. Furthermore, the inclined surface structure at the bottom of the fan-shaped groove optimizes stress distribution, preventing stress concentration at the groove bottom and further improving the product's structural reliability, ensuring the stability of the gears under long-term alternating loads.

[0055] In terms of process simplification and efficiency improvement, this process eliminates multiple cutting steps such as drilling and milling found in traditional processes, retaining only hot forging, finishing, and a small number of subsequent turning steps. This shortens machining time and significantly accelerates the production cycle, easily meeting customers' annual demand of hundreds of thousands of sets. At the same time, the increased mold life reduces mold replacement frequency and maintenance costs, the reduction in process steps lowers equipment investment and labor costs, and the improved material utilization rate ultimately leads to a reduction in overall mass production costs.

[0056] Furthermore, the precise control of the finishing process significantly improves the dimensional consistency of the forgings, with a precision fluctuation of ≤±0.02mm. Subsequent processing deformation is controllable, fully meeting the stringent requirements of high precision, high performance, low cost, and long service life for the main reduction gear of the motor. This provides an innovative paradigm for the near-net-shape forming process of core components of hybrid transmissions and also provides a replicable technical solution for the process optimization of similar complex structure forgings.

[0057] Reference Appendix Figure 1 Understandably, the hot forging machine tool in step four includes a machine plate frame 1, a row of variable force piles 3 fixed below the machine plate frame 1, and a tensioning device 4 installed on one side of the machine plate frame 1. The bottom end of the variable force piles 3 is connected to a cover pressure mold 5. The cover pressure mold 5 lowers down to cooperate with the stationary base mold to impact the forging 2.

[0058] Reference Appendix Figure 2Understandably, the variable force pile driver 3 includes a pile column 7 fixed on the machine plate frame 1, a pile plate 8 fixed at the bottom end of the pile column 7, multiple foot column devices 9 arranged around the pile plate 8, a brake 11 for positioning the foot column devices 9, a pressure device 6 for driving the brake 11, and a switch 10 for releasing the pressure device 6.

[0059] During the process of pressing the forging 2 by the cover die 5, the foot column device 9 applies a flexible thrust to the cover die 5 and applies a rigid thrust at the end of the pressing.

[0060] Reference Appendix Figure 4 Understandably, the tensioning device 4 includes a chain frame 13 fixed on the machine plate frame 1, an irregularly shaped chain 14 with upper limit support on the chain frame 13, a row of curved arc columns 15 fixed on the chain frame 13, and a pulling component 12 installed on the irregularly shaped chain 14. The arc-shaped pulling component 12 deforms and expands under the push of the curved arc columns 15, and the deformed and expanded pulling component 12 pushes the pressure tool 6 to reset.

[0061] The traction component 12 includes a parade seat 17 fixed on the irregular chain 14, a pusher 16 that slides directionally on the parade seat 17, and a pusher spring 18 for pushing the pusher 16 to reset. The pusher 16 is pushed by the upturned arc column 15 encountered during transport.

[0062] The foot post device 9 includes a column cylinder 20 that slides through a through hole in the pile plate 8, a spring 22 sleeved on the column cylinder 20, a frosted plate 19 and a limiting block 21 fixed at the top of the column cylinder 20, and the bottom end of the column cylinder 20 is fixedly connected to the cover mold 5.

[0063] The brake 11 includes a positioning frame 27 fixed on the pile 7, a support shaft 23 and a booster shaft 26 simultaneously supported on the positioning frame 27, a worm 24 with a worm gear fixed on the booster shaft 26 for meshing transmission, and a rubber scroll plate 25 fixed at the end of the booster shaft 26. The worm 24 is mounted on the positioning frame 27, and the worm 24 and the support shaft 23 establish transmission. The outer wall of the rotating rubber scroll plate 25 gradually comes into contact with the abrasive plate 19, and then positions the abrasive plate 19 through contact. A ring bevel gear is fixed on the worm 24 for perpendicular transmission with the bevel gear fixed on the support shaft 23. The support shaft 23, the worm 24 and the booster shaft 26 are respectively movably sleeved in different through holes opened on the positioning frame 27.

[0064] The pressure device 6 includes an annular spring 30 fixedly sleeved on the outside of the pile 7, an outer gear ring 29 fixedly sleeved on the outside of the annular spring 30, and a power storage rod 28 fixed on the outside of the outer gear ring 29. A fixed ring plate on the outer gear ring 29 is used to engage with an annular groove opened on the outer side wall of the pile 7. The pusher 16 is used to push the encountered power storage rod 28 to reset. A fixed gear on the support shaft 23 meshes with the outer gear ring 29 for transmission.

[0065] The switch 10 includes a subframe 34 fixed to the pile 7, a pressure-launching column 33 that slides longitudinally on the subframe 34, a blocking body 31 that slides laterally on the subframe 34, an extension shaft 32 that drives between the pressure-launching column 33 and the blocking body 31, a C-shaped spring 35 for pushing the pressure-launching column 33 to reset, a 1 / 2-direction resetting energy storage rod 28 of the blocking body 31, the pressure-launching column 33 for detecting the height of the cover mold 5, the pressure-launching column 33 sliding through a square hole opened in the subframe 34, and the subframe 34 being equipped with... The T-shaped post is inserted into the T-shaped groove on the arresting body 31. The lead-out shaft 32 is movably sleeved in the through hole on the sub-frame 34. One end of the lead-out shaft 32 is fixed with a gear to mesh with a row of teeth on the arresting body 31, and the other end of the lead-out shaft 32 is fixed with a gear to mesh with a row of teeth on the firing pin 33. One end of the C-shaped spring 35 is fixed to the firing pin 33, and pushes the sub-frame 34 to make the firing pin 33 tend to descend. A stop block is also fixed on the firing pin 33 to limit its descent height.

[0066] In the gear hot forging process, the red-hot forging 2 is first transported to the hot forging station. There is a stationary base mold directly below the forging 2 and a cover mold 5 directly above the forging 2. Then, the lifting mechanism drives the machine plate frame 1 to descend, the machine plate frame 1 drives the force converter 3, and then drives the cover mold 5 to descend. The cover mold 5 and the stationary base mold work together to impact the forging 2, thereby forming a product of the required shape between the cover mold 5 and the base mold.

[0067] The cover mold 5 of this invention does not employ the traditional rigid pressing technique. In order to improve the quality of hot forging, the cover mold 5 first flexibly presses down on the forging 2, providing a buffer for the deformation of the forging 2 and reducing the resistance of internal stress in the forging 2, thereby making the deformation of the forging 2 more stable. In the later stage of hot forging deformation, the cover mold 5 then applies rigid pressure to the forging 2, thereby making the forging 2 accurately shaped according to the specified shape. The forging 2, after initial shaping, is then transported to the next station for secondary hot forging impact shaping. This process continues until the required main reduction gear is produced.

[0068] The flexible pressure of the cover mold 5 on the forging 2 is due to the pressure spring 22 under the pile plate 8. The spring 22 provides thrust to the cover mold 5. The flexible pressure then switches to rigid pressure because the spring 22 fails. Specifically, the cover mold 5 encounters resistance when pressing the forging 2, forcing the cover mold 5 to get relatively close to the pile plate 8. Then, the cover mold 5 presses against the pressure column 33, which rises to drive the lead-out shaft 32 to rotate. Then, the blocking body 31 retracts to release the power storage rod 28, which in turn drives the annular spring 30 to drive the external gear ring 29 to rotate. The external gear ring 29 drives the support shaft 23, which then drives the booster shaft 26 to rotate through the worm gear 24. Then, the rotating rubber scroll plate 25 encounters the rising abrasive plate 19. The rubber scroll plate 25 contacts and positions the abrasive plate 19, thus fixing the pile plate 8, the column cylinder 20, and the cover mold 5 synchronously, thus achieving synchronous upgrading. The variable force pile driver 3 continues to descend, and the cover mold 5 will rigidly press the forging 2 until the forging 2 is completely hot-forged and shaped.

[0069] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A forming process for a sector-shaped bore main reduction gear, characterized in that, Includes the following steps: Step 1: Inspect raw materials and select materials with specified strength and hardness; Step 2: Material preparation. Cut the raw materials into blanks of the required size and weight according to the design requirements. Step 3: Chamfer to remove sharp edges and burrs; Step 4: Hot forging. The hot forging machine performs plastic deformation processing on the gear blank above the metal crystallization temperature, so that it is formed into the required tooth shape and geometry in the forging die. This is a near-net-shape forming process. Step 5: Normalizing treatment, a pre-heat treatment to improve the machinability of the material, refine the grains, and eliminate internal stress; Step Six: Shot blasting, a surface treatment that uses high-speed shot to impact the gear surface to achieve both cleaning and strengthening purposes; Step 7: Surface cleaning and lubrication to remove oil, cutting fluid and metal shavings from the gear surface; Step 8: Cold extrusion finishing. At room temperature, pressure is applied to the formed gear through a die to cause it to undergo slight plastic deformation. The hot forging machine tool in step four includes a machine plate frame, a row of variable force piles fixed below the machine plate frame, and a tensioning device installed on one side of the machine plate frame. The bottom end of the variable force pile is connected to a cover mold, which lowers to cooperate with the stationary base mold to impact the forging. The variable force pile driver includes a pile column fixed on the machine plate frame, a pile plate fixed at the bottom end of the pile column, multiple foot column devices arranged around the pile plate, a brake for positioning the foot column devices, a pressure device for driving the brake, and a switch for releasing the pressure device. During the pressing and impacting process of the cover die, the foot column device applies a flexible thrust to the cover die and a rigid thrust at the end of the pressing. The tensioning device includes a chain frame fixed on the machine plate frame, an irregular chain with upper limit support on the chain frame, a row of curved columns fixed on the chain frame, and a traction component installed on the irregular chain. The traction component with arc movement deforms and expands under the push of the curved columns, and the deformed and expanded traction component pushes the pressure tool to reset. The traction component includes a traveling seat fixed on the irregular chain, a pusher that slides directionally on the traveling seat, and a pusher spring for pushing the pusher to reset. The pusher is pushed by a curved column encountered during transport. The brake includes a positioning frame fixed on the pile, a support shaft and a booster shaft simultaneously supported on the positioning frame, a worm gear fixed on the booster shaft for meshing transmission, and a rubber scroll plate fixed at the end of the booster shaft. The worm gear is mounted on the positioning frame, and the worm gear and the support shaft establish a transmission.

2. The forming and processing technology of a sector-shaped bore main reduction gear according to claim 1, characterized in that: The fan-shaped groove bottom on the hot forging prepared in step four is designed with a sloping structure. Combined with the precise design of the mold cavity and the closed-loop control of the billet temperature, the fan-shaped groove structure is directly forged. The sloping design reduces the height of the mold teeth on one side.

3. The forming process of a sector-shaped bore main reduction gear according to claim 1, characterized in that: The cold extrusion finishing process in step eight achieves the calibration of dimensions, control of the diameter tolerance of the sector groove, and control of the groove position accuracy, eliminating the cumulative error of accuracy caused by multiple clamping.

4. The forming process of a sector-shaped bore main reduction gear according to claim 1, characterized in that: The foot post device includes a column that slides through a through hole in the pile plate, a spring sleeved on the column, a frosted plate and a limiting block fixed at the top of the column, and the bottom of the column is fixedly connected to the cover mold. The outer wall of the rotating rubber vortex plate gradually adheres to the frosted plate, thereby positioning the frosted plate through contact.

5. The forming process of a sector-shaped bore main reduction gear according to claim 1, characterized in that: The pressure device includes an annular spring fixedly sleeved on the outside of the pile, an outer gear ring fixedly sleeved on the outside of the annular spring, and a power storage rod fixed on the outside of the outer gear ring. A fixed ring plate on the outer gear ring is used to engage with an annular groove opened on the outer side wall of the pile. The pusher is used to push the encountered power storage rod to reset. A fixed gear on the support shaft meshes with the outer gear ring for transmission.

6. The forming process of a sector-shaped bore main reduction gear according to claim 5, characterized in that: The switch includes a subframe fixed to the pile, a pressure column that slides longitudinally on the subframe, a blocking body that slides laterally on the subframe, an output shaft that drives between the pressure column and the blocking body, and a C-shaped spring for pushing the pressure column to reset. The blocking body unidirectionally intercepts the reset energy storage rod, and the pressure column is used to detect the height of the cover mold.

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