Method for machining and heat treating a bevel gear and tooling therefor

Abstract

The application discloses a machining and heat treatment method of a bevel gear and a tool thereof and belongs to the technical field of gear manufacturing. The method comprises the following steps: first bevel structure internal tooth broaching is performed on a gear blank which has been roughly turned and finely turned, then carburizing normalizing heat treatment is performed after anti-carburizing treatment of the outer circle part, then second bevel structure internal tooth broaching is performed, and a once heat treated bevel gear is obtained; the once heat treated bevel gear is sleeved with a tool, and then carburizing quenching heat treatment is performed, and a twice heat treated bevel gear is obtained; bevel tooth tip grinding processing is performed on the twice heat treated bevel gear, and rough turning is performed on the outer circle part, and a twice heat treated and machined bevel gear is obtained; the outer circle part of the twice heat treated and machined bevel gear is finely turned and knurled, and the bevel gear is obtained. The machining and heat treatment processes are interlaced, the deformation of the part can be corrected in the process, and therefore the size qualified rate of the part finished product is improved.

Description

Technical Field

[0001] This invention belongs to the field of gear manufacturing technology, and relates to a machining and heat treatment method for wedge gears and its tooling. Background Technology

[0002] The one-way clutch is a crucial component in an automatic transmission (AT) system. Its function is to achieve one-way locking of the guide wheel, meaning the guide wheel can only rotate clockwise and not counterclockwise, enabling coupling and transmission in the high-speed range of the torque converter. One component is a support part with a thin-walled wedge-shaped wheel structure. The outer circle has a small-module spline, while the inner circle has a wedge-shaped eccentric tooth structure, with a thinner wall in the transition area. The tooth tips of the wedge-shaped eccentric tooth structure mate with the bearing, requiring good wear resistance. The eccentric tooth roots mate with the laminated springs and ball bearings. The overall dimensional accuracy of the part is high. Final product inspection requires plotting the contour of the wedge-shaped tooth section and comparing the offset with a standard contour to check for dimensional deviations.

[0003] Because the transition area of ​​this part has a thin wall thickness, the traditional processing technology is generally pre-heat machining → heat treatment → post-heat machining. After rough and finish turning in pre-heat machining, the wedge-shaped teeth are broached. The broaching step is generally divided into two steps: rough broaching and finish broaching. Then, a heat treatment process is carried out, including carburizing and quenching. After the heat treatment process is completed, the part is post-heat machined. For example, Chinese invention patent application number 202310669643.4 discloses "A process for preparing gears based on metal forging heat treatment," which involves machining the pre-treated workpiece before heat treatment. This operation only improves the mechanical strength of the gear and cannot improve its precision. Chinese invention patent application number 202111681211.2 discloses "A gear and its preparation method," which only introduces the gear heat treatment process, which also cannot effectively improve the gear precision. During the heat treatment process, the residual stress accumulated from the previous forging and machining processes is released, which can easily lead to problems such as excessive ellipticity or excessive taper, resulting in out-of-tolerance profiles in the wedge-shaped tooth area and affecting the final product yield. It is necessary to develop suitable machining and heat treatment processes for this part to ensure a high product yield. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problem in the prior art that wedge gears, during the heat treatment process, release the residual stress accumulated in the previous forging and machining processes, which easily leads to excessive ellipticity / excessive taper. This invention provides a machining and heat treatment method for wedge gears and its tooling.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] In a first aspect, the present invention provides a method for machining and heat treating a wedge-shaped gear, comprising the following steps:

[0007] S1, the gear blank that has been rough-turned and finish-turned is subjected to the first wedge-shaped internal gear broaching to obtain a wedge-shaped gear blank; the gear blank is a ring structure;

[0008] S2, after the outer circle of the wedge gear blank is treated to prevent carburizing, it is subjected to carburizing and normalizing heat treatment to obtain a wedge gear blank with one heat treatment.

[0009] S3, perform a second wedge-shaped internal tooth broaching on the wedge-shaped gear blank that has undergone primary heat treatment to obtain a primary heat-treated wedge gear;

[0010] S4. After machining and heat treatment tooling, the wedge gear sleeve that has undergone primary heat treatment is subjected to carburizing and quenching heat treatment to obtain a wedge gear that has undergone secondary heat treatment.

[0011] S5, the wedge gear undergoes wedge tooth tip grinding and rough turning of the outer diameter to obtain the secondary heat-treated and machined wedge gear;

[0012] S6. The outer diameter of the secondary heat-treated and machined wedge gear is precision turned and knurled to obtain the wedge gear.

[0013] A further improvement of the present invention is that:

[0014] It also includes the following steps:

[0015] Before performing step S4, the heat-treated wedge gear is cleaned and coated with an anti-carburization coating on its outer diameter. After coating, it is left at room temperature for 4-6 hours.

[0016] The first wedge-shaped internal tooth pull pin includes the following steps:

[0017] During the first broaching step, the broaching amount at the major diameter of the wedge-shaped gear blank is 3.2mm-3.6mm, and the broaching amount at the minor diameter of the wedge-shaped gear blank is 0.12mm-0.18mm. The major diameter of the wedge-shaped gear blank is a perfect circle.

[0018] During the second broaching step, the broaching amount at the major diameter of the wedge-shaped gear blank is 4.10mm-4.26mm, the minor diameter of the wedge-shaped blank is not machined, and the major diameter of the wedge-shaped blank is a perfect circle; the clamping fixture during broaching is a clamping fixture with tooth-aligning function, and the clamping fixture is connected to the lower chuck of the broach to prevent the broach from becoming eccentric during broaching;

[0019] In the third broaching step, the broaching amount at the major diameter of the wedge of the gear blank is 3.25mm-3.35mm, and the broaching amount at the minor diameter of the wedge is 0.08mm-0.12mm. At this time, the major diameter of the wedge is an eccentric circle, and the fixture for broaching is a fixture with tooth-aligning function.

[0020] The process of preventing carburization on the outer circumference of the wedge gear blank includes the following steps:

[0021] Apply an anti-carburization coating to the outer circumference of the wedge gear blank, and leave it at room temperature for 4-6 hours after coating.

[0022] The carburizing and normalizing heat treatment includes the following steps:

[0023] After the outer circumference of the wedge gear blank has undergone anti-carburizing treatment, it is placed in a heat treatment furnace with one end face of the wedge gear blank in contact with the heat treatment tray fixture. Under the protection of nitrogen-methanol atmosphere, it is heated to a temperature range of 890℃-925℃ for carburizing heat treatment, with the carbon potential set at 1.15-1.25 and the carburizing time at 6-10 hours. Then, the carbon potential is reduced to 0.95-1.1 and diffusion treatment is performed for 2-4 hours. Next, the temperature is lowered to 840℃-860℃, and the blank is cooled in the heat treatment furnace with nitrogen for 2-3 hours before being pulled out.

[0024] The second wedge-shaped internal gear broaching of the first heat-treated wedge gear blank includes the following steps:

[0025] The wedge-shaped internal teeth of the wedge-shaped gear blank are broached by 0.12mm-0.18mm at the major diameter and 0.03mm-0.07mm at the minor diameter to effectively modify the wedge-shaped structure and remove the deformation, thus obtaining the wedge-shaped gear after heat treatment.

[0026] The process of carburizing and quenching heat treatment after fitting the tooling onto the wedge gear that has undergone primary heat treatment includes the following steps:

[0027] A fixture is fitted onto the outer circumference of the first heat-treated wedge gear, and the first heat-treated wedge gear is placed in the heat treatment furnace so that one end face of the first heat-treated wedge gear contacts the heat treatment material tray fixture for a second heating and quenching process. Under the protection of nitrogen-methanol atmosphere, the gear is heated to a temperature range of 800℃-830℃ for carburizing heat treatment, with the carbon potential set at 0.8-0.9 and the holding time at 1.5-3 hours. Then, quenching is performed using quenching oil as the quenching medium.

[0028] The process of grinding the wedge teeth tip and rough turning the outer diameter of the secondary heat-treated wedge gear includes the following steps:

[0029] After positioning the wedge-shaped tooth tip of the secondary heat-treated wedge gear, rough turn its outer circle to ensure consistency between the outer circle and the tooth tip of the internal tooth. Then, clamp the rough-turned outer circle of the secondary heat-treated wedge gear and grind the tooth tip of the internal tooth of its wedge structure. The grinding amount is 0.12mm-0.18mm to correct the minor diameter deformation caused by heat treatment deformation, thus obtaining the secondary heat-treated and machined wedge gear.

[0030] The process of precision turning and knurling the outer diameter of the secondary heat-treated and machined wedge gear includes the following steps:

[0031] The minor diameter of the wedge gear after secondary heat treatment and machining is precision machined to correct the deformation of the outer diameter, and then the minor diameter is positioned for knurling.

[0032] Secondly, the present invention provides a machining and heat treatment fixture for the aforementioned wedge gear, characterized in that the machining and heat treatment fixture is a ring; the inner ring of the ring is clearance-fitted with the outer ring of the first heat-treated wedge gear.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] This invention discloses a machining and heat treatment method for wedge-shaped gears, employing a process scheme of pre-heat machining → primary heat treatment → post-heat machining → secondary heat treatment → final machining. By interleaving machining and heat treatment processes, deformation of the part can be corrected during the process, thereby improving the dimensional qualification rate of the finished part. Post-heat machining can effectively correct the deformation caused by the release of residual stress accumulated in the pre-heat process, improving the wedge-shaped tooth deformation of the part during the process. After quenching, the part undergoes a structural transformation and produces partial deformation, which is the result of the combined effect of thermal stress and structural stress. Compared with the traditional one-step carburizing and quenching process, the amount of deformation caused by stress release is significantly reduced. During the secondary heat treatment, tooling is added to the outside of the part, which indirectly increases the wall thickness of the part, reduces the deformation tendency of the part, and thus controls the dimensional deformation of the part. After machining the part using this machining and heat treatment method, the internal wedge profile accuracy of 0.1 and the spline accuracy requirements in the drawing can be guaranteed. In addition, since the parts need to be broached into wedges after carburizing, it is necessary to ensure that the teeth maintain low hardness. Therefore, the outer circle of the parts is treated with anti-carburizing treatment before the first heat treatment to ensure that enough carbon elements are penetrated into the surface layer, so as to ensure that the final hardened layer depth of the product meets the requirements of the drawing.

[0035] Furthermore, preheating machining employs a three-step broaching process. In traditional machining processes, the first step, rough broaching, involves a larger broaching amount, while the second step, finish broaching, involves a smaller broaching amount. Compared to the two-step broaching process in traditional machining, the three-step broaching process can effectively reduce the residual stress accumulated during the machining of parts and reduce the deformation caused by the release of residual stress after heat treatment. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 A three-dimensional structural diagram of a wedge gear manufactured using the machining and heat treatment methods of this invention;

[0038] Figure 2 This is a front view of a wedge gear manufactured using the machining and heat treatment methods described in this invention.

[0039] Figure 3 A three-dimensional structural diagram of the part after the first wedge-shaped internal gear broaching of the gear blank in this invention;

[0040] Figure 4 A front view of the part after the first wedge-shaped internal gear broaching of the gear blank in this invention;

[0041] Figure 5 This is a front view of the part being fitted with tooling during secondary heat treatment in this invention;

[0042] Figure 6 This is a cross-sectional view of the tooling being fitted onto the part during the secondary heat treatment of the part in this invention;

[0043] Figure 7 This is a partially enlarged cross-sectional view of the end face protrusion on one end face of the part in this invention;

[0044] Figure 8 This is a cross-sectional view of the machining and heat treatment fixture in this invention;

[0045] Figure 9 This is a front view of the machining and heat treatment fixture in this invention.

[0046] Wherein: 1-wedge gear; 2-wedge gear blank; 3-wedge gear with primary heat treatment; 4-external spline; 5-machining and heat treatment tooling; 6-end face protrusion. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0048] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0049] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0050] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0051] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0052] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0053] The present invention will now be described in further detail with reference to the accompanying drawings:

[0054] This invention discloses a machining and heat treatment method for wedge gears, comprising the following steps:

[0055] See Figure 1 and Figure 2 Here is a structural diagram of the wedge gear 1 manufactured using the method of this embodiment;

[0056] See Figure 3 and Figure 4This is a structural diagram of the wedge-shaped gear blank 2 obtained after the gear blank undergoes the first wedge-shaped internal tooth broaching when using the method of this embodiment;

[0057] See Figure 5 and Figure 6 This is a structural diagram of the machining and heat treatment fixture 5 when the wedge gear 3 undergoes secondary heat treatment after primary heat treatment using the method of this embodiment.

[0058] See Figure 7 The wedge gear produced by the method of this embodiment has two end faces. Before the final machining is completed, one end face is a plane, and the other end face has an end face protrusion 6 near the outer end. This face is called a convex face. The end face protrusion 6 is an annular protrusion.

[0059] See Figure 8 and Figure 9 , is the machining and heat treatment fixture 5 used in this embodiment. The fixture is a ring, and the inner ring of the ring is in clearance fit with the outer ring of the first heat treatment wedge gear.

[0060] Perform machining and heat treatment according to the following steps:

[0061] Step 1: Prepare the rough-turned and finish-turned gear blanks, and perform wedge-shaped internal gear broaching to obtain wedge-shaped gear blank 2; the gear blank is a ring structure.

[0062] The broaching process consists of three steps. In the first step, the part is positioned with the convex side facing down for broaching. The broaching amount at the major diameter of the wedge is 3.2-3.6 mm, and the broaching amount at the minor diameter is 0.12-0.18 mm. The major diameter is a perfect circle.

[0063] Step 2: Position the part with the convex side facing down for broaching. The broaching amount at the major diameter of the wedge is 4.10-4.26mm, while the minor diameter is left unmachined, and the major diameter remains a perfect circle. Use a fixture with tooth-aligning function during broaching. The fixture is connected to the lower chuck of the broach to prevent the broach from becoming eccentric during broaching.

[0064] Step 3: Position the part with the convex side facing down for broaching. The broaching amount at the major diameter of the wedge is 3.25-3.35mm, and the broaching amount at the minor diameter is 0.08-0.12mm. At this time, the major diameter is an eccentric circle. Use a jig with tooth-aligning function during broaching.

[0065] In traditional machining processes, the first step of rough broaching involves a large amount of material removed, while the second step of finish broaching involves a smaller amount of material removed. Compared to the two-step broaching process in traditional machining, three-step broaching can effectively reduce the residual stress accumulated during the machining process and reduce the deformation caused by the release of residual stress after heat treatment.

[0066] Step 2: Perform anti-carburizing treatment on the outer circumference of the wedge gear blank 2. The outer spline area of ​​this part requires a low hardness to avoid carburizing and quenching. Therefore, a coating is applied to the outer circumference to prevent carbon penetration in subsequent processes. After coating, allow it to stand at room temperature for 4-6 hours to ensure complete curing.

[0067] Step 3: After the outer circle of the wedge gear blank 2 is treated to prevent carburizing, it is subjected to carburizing and normalizing heat treatment to obtain a wedge gear blank that has undergone one heat treatment.

[0068] Place the wedge-shaped gear blank in the heat treatment furnace, lay it flat with the convex side facing up, and make the other end face of the part contact the heat treatment tray fixture. Under the protection of nitrogen-methanol atmosphere, heat it to a temperature range of 890-925℃ for carburizing heat treatment, set the carbon potential to 1.15-1.25, and the carburizing time is 6-10 hours. Then reduce the carbon potential to 0.95-1.1 and perform diffusion treatment for 2-4 hours. Then lower the temperature to 840-860℃, cool it in the heat treatment furnace with nitrogen for 2-3 hours, and then pull it out.

[0069] In this method, since the parts need to be broached into wedges after carburizing, it is necessary to ensure that the teeth maintain low hardness. Therefore, carburizing and normalizing treatment is required first to ensure that enough carbon elements are diffused into the surface layer so as to ensure that the final hardened layer depth of the product meets the drawing requirements.

[0070] Step 4: Perform a second broaching of the internal teeth of the wedge structure on the wedge gear blank after the first heat treatment to obtain the first heat-treated wedge gear 3.

[0071] The part is made of low-carbon alloy steel. After carburizing and normalizing heat treatment, stress release causes changes in the dimensions of the internal teeth of the wedge-shaped structure, resulting in a deterioration in the elliptical and tapered dimensions. A secondary broaching process is required to correct this structural deformation. After carburizing and normalizing, carbon elements diffuse into the surface layer, but without quenching, the microstructure undergoes a martensitic transformation, and the matrix remains soft. Compared to the matrix hardness before carburizing and normalizing, the hardness increases by approximately 5 HRC. The broach before heat treatment still possesses the capability to machine the part, allowing for broaching of the internal teeth of the wedge-shaped structure. The broaching dimensions at this stage, compared to the broaching dimensions before heat treatment, are 0.12-0.18 mm at the major diameter and 0.03-0.07 mm at the minor diameter, effectively reshaping the internal teeth of the wedge-shaped structure and removing deformation.

[0072] This step can effectively correct the deformation caused by the release of residual stress accumulated in the preheating process, and improve the deformation of the wedge teeth of the part during the process.

[0073] Step 5: After cleaning the heat-treated wedge gear 3, apply a waterproof coating to the outer circumference and leave it at room temperature for 4-6 hours to ensure complete solidification. After carburizing and normalizing, some of the waterproof coating may fail, requiring reapplication of the coating to the outer circumference.

[0074] Step 6: Fit the machining and heat treatment fixture 5 onto the outer circle of the part obtained in step 5, place the part in the heat treatment furnace, lay it flat with the convex side facing up, so that the other end face of the part contacts the heat treatment tray fixture, and perform a secondary heating and quenching process to obtain a secondary heat-treated wedge gear.

[0075] Under the protection of nitrogen-methanol atmosphere, the material is heated to a temperature range of 800-830℃ for carburizing heat treatment, with the carbon potential set at 0.8-0.9 and the holding time at 1.5-3 hours. Then, it is quenched using quenching oil as the quenching medium.

[0076] After quenching, the part undergoes a structural transformation and partial deformation. This is the result of the combined effect of thermal stress and structural stress. Compared with the traditional one-step carburizing and quenching process, the amount of deformation caused by stress release is greatly reduced. After externally fitting the machining and heat treatment fixture 5, the wall thickness of the part is increased in effect, reducing the deformation tendency of the part and thus controlling the dimensional deformation of the part.

[0077] Step 7: Perform wedge tooth tip grinding and rough turning on the outer diameter of the secondary heat-treated wedge gear to obtain the secondary heat-treated and machined wedge gear.

[0078] Because an anti-carburization coating is used to protect the outer diameter during heat treatment, carbon elements do not penetrate into this area. After quenching, this area retains a relatively low hardness, facilitating post-heat machining. First, the outer diameter of the part is rough-machined using a wedge-shaped tooth tip to ensure consistency between the outer diameter and the inner tooth tip. Then, the rough-machined outer diameter is clamped and the tooth tip of the wedge-shaped inner tooth structure is ground. The grinding amount is 0.12-0.18 mm. This grinding corrects minor diameter deformation caused by heat treatment.

[0079] Step 8: Perform precision turning and knurling on the outer diameter of the secondary heat-treated and machined wedge gear to obtain wedge gear 1.

[0080] Because an anti-carburization coating is used to protect the outer diameter during heat treatment, carbon elements do not penetrate into the outer diameter. After quenching, this area retains a low hardness, facilitating post-heat machining. The minor diameter, after being corrected by positioning grinding, is then precision-machined on the outer diameter of the part to further correct the deformation of the outer diameter. Finally, the minor diameter is used to machine the outer edge spline 4.

[0081] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for machining and heat treatment of a wedge-shaped gear, characterized in that, Includes the following steps: S1, the gear blank that has undergone rough turning and finish turning is subjected to the first wedge-shaped internal gear broaching to obtain a wedge-shaped gear blank; the gear blank is a ring structure; the first wedge-shaped internal gear broaching includes the following steps: During the first broaching step, the broaching amount at the major diameter of the wedge-shaped gear blank is 3.2mm-3.6mm, and the broaching amount at the minor diameter of the wedge-shaped gear blank is 0.12mm-0.18mm. The major diameter of the wedge-shaped gear blank is a perfect circle. During the second broaching step, the broaching amount at the major diameter of the wedge-shaped gear blank is 4.10mm-4.26mm, the minor diameter of the wedge-shaped blank is not machined, and the major diameter of the wedge-shaped blank is a perfect circle; the clamping fixture during broaching is a clamping fixture with tooth-aligning function, and the clamping fixture is connected to the lower chuck of the broach to prevent the broach from becoming eccentric during broaching; In the third broaching step, the broaching amount at the major diameter of the wedge of the gear blank is 3.25mm-3.35mm, and the broaching amount at the minor diameter of the wedge is 0.08mm-0.12mm. At this time, the major diameter of the wedge is an eccentric circle, and the fixture for broaching is a fixture with tooth-aligning function. S2, after the outer circle of the wedge gear blank is treated to prevent carburizing, it is subjected to carburizing and normalizing heat treatment to obtain a wedge gear blank with one heat treatment. S3, perform a second wedge-shaped internal tooth broaching on the wedge-shaped gear blank that has undergone primary heat treatment to obtain a primary heat-treated wedge gear; S4. After machining and heat treatment tooling on the first heat-treated wedge gear sleeve, carburizing and quenching heat treatment is performed to obtain the second heat-treated wedge gear. S5, the wedge gear undergoes wedge tooth tip grinding and rough turning of the outer diameter to obtain the secondary heat-treated and machined wedge gear; S6. The outer diameter of the secondary heat-treated and machined wedge gear is precision turned and knurled to obtain the wedge gear.

2. The machining and heat treatment method for wedge gears according to claim 1, characterized in that, It also includes the following steps: Before performing step S4, the heat-treated wedge gear is cleaned and coated with an anti-carburization coating on its outer diameter. After coating, it is left at room temperature for 4-6 hours.

3. The machining and heat treatment method for wedge gears according to claim 1, characterized in that, The process of preventing carburization on the outer circumference of the wedge gear blank includes the following steps: Apply an anti-carburization coating to the outer circumference of the wedge gear blank, and leave it at room temperature for 4-6 hours after coating.

4. The machining and heat treatment method for wedge gears according to claim 1, characterized in that, The carburizing and normalizing heat treatment includes the following steps: After the outer circumference of the wedge gear blank has undergone anti-carburizing treatment, it is placed in a heat treatment furnace with one end face of the wedge gear blank in contact with the heat treatment tray fixture. Under the protection of nitrogen-methanol atmosphere, it is heated to a temperature range of 890℃-925℃ for carburizing heat treatment, with the carbon potential set at 1.15-1.25 and the carburizing time at 6-10 hours. Then, the carbon potential is reduced to 0.95-1.1 and diffusion treatment is performed for 2-4 hours. Next, the temperature is lowered to 840℃-860℃, and the blank is cooled in the heat treatment furnace with nitrogen for 2-3 hours before being pulled out.

5. The machining and heat treatment method for wedge gears according to claim 1, characterized in that, The second wedge-shaped internal gear broaching of the first heat-treated wedge gear blank includes the following steps: The wedge-shaped internal teeth of the wedge-shaped gear blank are broached by 0.12mm-0.18mm at the major diameter and 0.03mm-0.07mm at the minor diameter to effectively modify the wedge-shaped structure and remove the deformation, thus obtaining the wedge-shaped gear after heat treatment.

6. The machining and heat treatment method for wedge gears according to claim 1, characterized in that, The process of machining and heat-treating the wedge-shaped gear sleeve after primary heat treatment, followed by carburizing and quenching heat treatment, includes the following steps: A fixture is fitted onto the outer circumference of the first heat-treated wedge gear, and the first heat-treated wedge gear is placed in the heat treatment furnace so that one end face of the first heat-treated wedge gear contacts the heat treatment material tray fixture for a second heating and quenching process. Under the protection of nitrogen-methanol atmosphere, the gear is heated to a temperature range of 800℃-830℃ for carburizing heat treatment, with the carbon potential set at 0.8-0.9 and the holding time at 1.5-3 hours. Then, quenching is performed using quenching oil as the quenching medium.

7. The machining and heat treatment method for wedge gears according to claim 1, characterized in that, The process of grinding the wedge teeth tip and rough turning the outer diameter of the secondary heat-treated wedge gear includes the following steps: After positioning the wedge-shaped tooth tip of the secondary heat-treated wedge gear, rough turn its outer circle to ensure consistency between the outer circle and the tooth tip of the internal tooth. Then, clamp the rough-turned outer circle of the secondary heat-treated wedge gear and grind the tooth tip of the internal tooth of its wedge structure. The grinding amount is 0.12mm-0.18mm to correct the minor diameter deformation caused by heat treatment deformation, thus obtaining the secondary heat-treated and machined wedge gear.

8. The machining and heat treatment method for wedge gears according to claim 1, characterized in that, The process of precision turning and knurling the outer diameter of the secondary heat-treated and machined wedge gear includes the following steps: The minor diameter of the wedge gear after secondary heat treatment and machining is precision machined to correct the deformation of the outer diameter, and then the minor diameter is positioned for knurling.

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