A process for forming an inner bore profiled ring of a ring gear

Abstract

This invention discloses a process for forming the inner hole teeth of a gear ring by rolling, the steps of which include: 1) sawing a cylindrical bar to form a raw billet; 2) heating the raw billet to 1230-1250℃ and holding it at that temperature for more than 3 hours; 3) upsetting the raw billet to form an upset billet; 4) punching a circular hole in the center of the upset billet to form a circular ring billet; 5) enlarging the hole in the circular ring billet to form a pre-expanded ring billet; then, reheating it in the furnace to 1230-1250℃ and holding it at that temperature for more than 2 hours; 6) rolling the ring again to form a re-expanded ring billet; 7) continuing to roll the re-expanded ring billet so that the outer diameter of the final expanded ring billet is equivalent to the outer diameter of the gear ring formed by rolling; 8) using planetary gears to roll the inner hole of the final expanded ring billet to form a gear ring formed by rolling; 9) after cooling, precision machining the inner hole teeth of the gear ring formed by rolling to obtain the gear ring. The internal toothed ring forming process described in this invention can significantly improve material utilization and shorten the production cycle.

Description

Technical Field

[0001] This invention relates to the manufacturing process of large and medium-sized gear rings, and more particularly to a grinding ring forming process for the inner hole tooth profile of a gear ring. Background Technology

[0002] Among various new energy sources, wind power generation is relatively mature in technology and has relatively low manufacturing costs for wind turbine gearboxes. Therefore, wind turbine gearboxes have broad development prospects in the future. As one of the more important components of a gearbox, the wind turbine internal gear ring is currently facing increasingly fierce market competition. Manufacturers are all working hard to improve product quality and reduce manufacturing costs. Therefore, the key to gaining a competitive edge in the market lies in how to ensure product quality while improving material utilization, reducing manufacturing costs, and shortening the production cycle.

[0003] Currently, the traditional forming process for wind turbine internal gear rings involves the following steps: obtaining a smooth inner and outer ring blank through forging and rolling; then, completing the tooth profile on the internal gear ring through subsequent cold working methods (such as gear shaping, gear hobbing, or gear broaching). The disadvantages of this forming process are: 1. Low material utilization: Cold cutting removes a large amount of forged material, resulting in considerable waste of "iron shavings". Therefore, the weight of the rough blank is more than 1.2 times the weight of the final formed wind turbine inner ring tooth.

[0004] 2. Long production cycle: It adds a separate and time-consuming tooth profile machining process. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a rolling process for the inner hole tooth profile of a gear ring that can improve material utilization and shorten the production cycle.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a process for forming the inner tooth profile of a gear ring, the steps of which include: 1) The cylindrical bar stock is sawn to form the original billet. Assume: the diameter of the cylindrical bar stock is D0 (cm), the weight of the finished gear ring is W9 (g), and the density of the finished gear ring is ρ (g / cm³). Then, the height of the original billet... Where k9 ≥ 1.035; 2) Heat the original billet to between 1230 and 1250°C and hold for at least 3 hours; 3) Upset the original billet so that the ratio of the height of the upset billet to the height of the original billet is ≥3, that is: upsetting ratio ≥3; and the ratio of the height of the upset billet to the height of the finished gear ring is ≥1.2; 4) Punch a circular hole through the upsetting billet at the center of the upsetting billet, so that the diameter of the hole in the formed annular billet is larger than the diameter of the pre-expanded core roller, and the weight ratio of the annular billet to the weight of the original billet is ≥0.975. 5) Transfer the annular billet to the ring rolling mill and expand the annular billet with a pre-expanding mandrel to increase the inner diameter of the annular billet. The inner diameter of the annular billet minus the tooth tip diameter of the planetary gear on the mandrel with planetary gears used for rolling the teeth should be ≥100 mm to form the initially expanded annular billet. Then, return it to the furnace and heat it to 1230-1250℃ and hold it for more than 2 hours. 6) Take the initially expanded annular billet to the ring rolling mill for re-rolling, so that the outer diameter of the re-expanded annular billet reaches 98.25% to 98.75% of the inner diameter of the annular outer mold tooling. 7) The annular outer mold tooling is used to frame the re-expanded annular blank. A mandrel is used to continue rolling the re-expanded annular blank, ensuring that the final expanded annular blank formed in this rolling process has a diameter comparable to the inner diameter of the annular outer mold tooling. Simultaneously, the height of the final expanded annular blank needs to be controlled. , Where 1.01≤K1≤1.0116, V0 is the volume of the original billet, 0.77≤K2≤0.83, H1 is the height of the annular billet, d1 is the inner diameter of the annular billet, D4 is the outer diameter of the final expanded annular billet = the inner diameter of the annular outer mold tooling, and d4 is between 101.18% and 101.89% of the tooth tip circle diameter from the rolled ring to the finished tooth ring. 8) A core roller with planetary gears is used to grind the inner hole of the final expanded annular blank. During the grinding process, the core roller is gradually moved inward so that the tooth tip diameter of the final expanded annular blank is equivalent to the tooth tip circle diameter of the finished tooth ring, forming a toothed tooth ring. 9) After the gear ring is cooled, rough turn the upper and lower surfaces and the outer cylindrical surface of the gear ring, and then finish turn the inner teeth of the gear ring to obtain the finished gear ring.

[0007] As a preferred embodiment, in the inner hole tooth profile rolling ring forming process of the toothed ring, the ratio of the weight of the annular blank to the weight of the original blank in step 4) is ≥0.98.

[0008] As a preferred embodiment, in the inner hole tooth profile rolling ring forming process of the aforementioned tooth ring, the heat preservation time in step 2) is controlled between 3 and 4 hours.

[0009] As a preferred embodiment, in the above-mentioned process for forming the inner hole tooth profile of a gear ring, step 5) involves expanding the hole with a pre-expanding core roller so that the inner hole diameter of the annular blank minus the outer diameter of the planetary gear tooth profile tool is ≤200 mm. As a preferred embodiment, in the inner hole tooth profile rolling ring forming process of the aforementioned tooth ring, the holding time for reheating in step 5) is controlled between 2 and 3 hours.

[0010] As a preferred embodiment, in the inner hole tooth profile rolling ring forming process of the tooth ring, the ratio of the weight of the rolled tooth ring to the weight of the original blank is ≥0.97.

[0011] As a preferred embodiment, in the inner hole tooth profile rolling ring forming process of the aforementioned tooth ring, the core roller in step 7) and the core roller with planetary gear in step 8) are the same core roller, the upper part of which is used to roll the re-expanded annular blank, and the lower part of which is used to roll the teeth of the inner hole of the final expanded annular blank.

[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention controls the weight of the annular blank by sawing in step 1) and punching the round hole in step 2), so that the weight ratio of the annular blank to the original blank is ≥0.975. Then, by controlling the inner and outer diameters of the final expanded annular blank, the final expanded annular blank reaches the set height. After the final expanded annular blank is rolled into a ring, the planetary gear on the core roller with planetary gears is used to roll the inner hole of the final expanded annular blank to form a rolled toothed ring. That is, the inner hole tooth shape is basically formed. Thus, only a small amount of material needs to be precision machined after the rolled toothed ring cools, which reduces the loss and saves about 14% of the material, improves the material utilization rate, and shortens the production cycle.

[0013] 2. By controlling the upper limit of the heat preservation time in steps 2) and 5), the present invention further shortens the production cycle and improves production efficiency.

[0014] 3. By controlling the diameter of the pre-expanded hole in step 5), this invention ensures both the smooth progress of the pre-expanding process and the smooth progress of the subsequent rolling ring and rolling teeth after reheating, thereby further shortening the production cycle and improving production efficiency.

[0015] 4. Since the same core roller is used in steps 7) and 8) of this invention, the cost is saved. During use, the conversion between the grinding ring and the grinding teeth can be achieved simply by moving the core roller up and down, which saves the time of switching core rollers, further shortens the production cycle and improves production efficiency. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the original billet structure.

[0017] Figure 2 This is a schematic diagram of the structure of the billet after upsetting.

[0018] Figure 3 This is a schematic diagram of the structure of a circular annular blank.

[0019] Figure 4 This is a schematic diagram of the structure of the initial expanded annular billet.

[0020] Figure 5 This is a schematic diagram of the structure of the expanded annular billet.

[0021] Figure 6 This is a schematic diagram of the final expanded annular billet structure.

[0022] Figure 7 This is a schematic diagram showing the state of the gear grinding process.

[0023] Figure 8 yes Figure 7 A partial structural diagram viewed from above.

[0024] Figure 9 This is a structural diagram of the finished gear ring.

[0025] Figures 1 to 9 The reference numerals in the attached figures are as follows: 1. Original billet, 2. Upset billet, 3. Circular ring billet, 4. Initially expanded ring billet, 5. Further expanded ring billet, 6. Final expanded ring billet, 8. Gear ring formed by grinding, 9. Finished gear ring, 11. A pair of conical clamping rollers, 12. Main roller, 13. Core roller, 131. Planetary gear, 14. Circular outer mold tooling. Detailed Implementation

[0026] The following describes in detail, with reference to the accompanying drawings, a detailed embodiment of the inner hole tooth profile rolling ring forming process of the present invention.

[0027] The present invention discloses a process for forming the inner tooth profile of a gear ring, the steps of which include: 1) A cylindrical alloy steel bar with a diameter of 59.5 cm and a density of 7.85 g / cm³ is sawn. The weight of the finished gear ring is calculated to be 39,408,000 g using three-dimensional calculation. The resulting original blank 1 (see...) Figure 1 (as shown) height 191 (cm), that is: the height H0 of the original billet 1 is 1910 mm. To be on the safe side, k9 is taken as 1.058 here; 2) Heat the original billet 1 to between 1230 and 1250°C and hold for 3 to 4 hours; 3) Upset the original billet to obtain upset billet 2 (see Figure 2The height H1 (as shown) is 510 mm (approximately 1.2143 of the final finished gear ring height H9 = 420 mm). The upsetting ratio is H0 ÷ H1 = 1910 ÷ 510 ≈ 3.7451. The upsetting ratio is usually controlled within 4 to reduce forging time and shorten the production cycle. 4) A 300 mm diameter hole is punched through the center of the upset blank 2 to form a ring-shaped blank 3 (see...). Figure 3 As shown in the figure, during the punching of the round hole, there is a loss of a cylindrical bar with a diameter of 300 mm and a height of 100 mm, which makes the weight ratio of the annular blank to the weight of the original blank about 0.9867. 5) Transfer the annular billet 3 to the ring rolling mill, and use a pre-expanding core roller to expand the annular billet 3, so that the diameter d2 of the inner hole of the annular billet 3 increases to 850 mm, forming the initially expanded annular billet 4 (see...). Figure 4 (as shown); then reheat in the furnace to between 1230 and 1250°C and hold for 2 to 3 hours; 6) Use the discharge machine to clamp the initially expanded ring billet 4 to the ring rolling mill for re-rolling, such as... Figure 5 As shown, a pair of conical clamping rollers 11 of the ring rolling mill clamp one side of the initially expanded annular billet 4, while the other side abuts against the main roller 12 of the ring rolling mill. The upper part of the core roller 13 is used to roll the outer diameter D3 of the initially expanded annular billet 4 to 2300 mm and the inner diameter d3 of the initially expanded annular billet 4 to 1965 mm, forming a re-expanded annular billet 5. The outer diameter D3 of the re-expanded annular billet 5 is approximately 98.5% of the inner diameter 2335 mm of the annular outer mold tooling 14; the inner diameter 2335 mm of the annular outer mold tooling 14 is approximately 101.70% of the finished gear ring 2296 mm. 7) See Figure 6 As shown, the annular outer mold fixture 14 (hereinafter referred to as the outer mold) frames the re-expanded annular blank 5, and the core roller 13 is used to continue rolling the re-expanded annular blank 5 into a ring. At the same time, it is necessary to control the height of the final expanded annular blank 6, which is formed in this rolling process and has a similar inner diameter to the annular outer mold fixture 14. , Where: 1.01≤K1≤1.0116; V0=π×(595÷2)×(595÷2)×1910, the unit is cubic millimeters; 0.77≤K2≤0.83; d1=300 mm; D4=2335 mm; d4=1986 mm, which is approximately 101.59% of the tooth tip circle diameter of the finished tooth ring 9, which is 1955 mm; 8) For example Figure 7 and Figure 8As shown, the planetary gear 131 on the core roller 13 is used to grind the inner hole of the final expanded annular blank 6 to form a toothed ring 8. During the grinding process, the core roller 13 is gradually retracted inward, so that the tooth tip diameter (cold state) of the final expanded annular blank 6 is about 1935 mm and its tooth tip diameter (hot state) is about 1955 mm, which is equivalent to the tooth tip circle diameter of the finished tooth ring 9. 9) After the gear ring 8 has cooled, first rough-machine the upper and lower surfaces and the outer cylindrical surface of the gear ring 8, and then finish-machine the inner teeth of the gear ring 8 to obtain the finished gear ring 9 (see...). Figure 9 (As shown).

[0028] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made based on the claims of the present invention are within the scope of protection of the present invention.

Claims

1. A process for forming the inner tooth profile of a gear ring, comprising the following steps: 1) The cylindrical bar stock is sawn to form the original billet. Assume: the diameter of the cylindrical bar stock is D0 (cm), the weight of the finished gear ring is W9 (g), and the density of the finished gear ring is ρ (g / cm³). Then, the height of the original billet... The unit is centimeters, where k9 ≥ 1.035; 2) Heat the original billet to between 1230 and 1250°C and hold for at least 3 hours; 3) Upset the original billet so that the ratio of the height of the upset billet to the height of the original billet is ≥3, that is: upsetting ratio ≥3; and the ratio of the height of the upset billet to the height of the finished gear ring is ≥1.2; 4) Punch a circular hole through the upsetting billet at the center of the upsetting billet so that the diameter of the hole in the resulting annular billet is larger than the diameter of the pre-expanded core roller. 5) Transfer the annular billet to the ring rolling mill and expand the annular billet with a pre-expanding mandrel to increase the inner diameter of the annular billet. The inner diameter of the annular billet minus the tooth tip diameter of the planetary gear on the mandrel with planetary gears used for rolling the teeth should be ≥100 mm to form the initially expanded annular billet. Then, return it to the furnace and heat it to 1230-1250℃ and hold it for more than 2 hours. 6) Take the initially expanded annular billet to the ring rolling mill for re-rolling, so that the outer diameter of the re-expanded annular billet reaches 98.25% to 98.75% of the inner diameter of the annular outer mold tooling. 7) The annular outer mold tooling is used to frame the re-expanded annular blank. A mandrel is used to continue rolling the re-expanded annular blank, ensuring that the final expanded annular blank formed in this rolling process has a diameter comparable to the inner diameter of the annular outer mold tooling. Simultaneously, the height of the final expanded annular blank needs to be controlled. ， Where 1.01≤K1≤1.0116, V0 is the volume of the original billet, 0.77≤K2≤0.83, H1 is the height of the annular billet, d1 is the inner diameter of the annular billet, D4 is the outer diameter of the final expanded annular billet = the inner diameter of the annular outer mold tooling, and d4 is between 101.18% and 101.89% of the tooth tip circle diameter from the rolled ring to the finished tooth ring. 8) A core roller with planetary gears is used to grind the inner hole of the final expanded annular blank. During the grinding process, the core roller is gradually moved inward so that the tooth tip diameter of the final expanded annular blank is equivalent to the tooth tip circle diameter of the finished tooth ring, forming a toothed tooth ring. 9) After the gear ring is cooled, rough turn the upper and lower surfaces and the outer cylindrical surface of the gear ring, and then finish turn the inner teeth of the gear ring to obtain the finished gear ring.

2. The inner tooth profile rolling ring forming process of a gear ring according to claim 1, characterized in that, In step 4), the ratio of the weight of the annular billet to the weight of the billet after upsetting is ≥0.

98.

3. The inner tooth profile rolling ring forming process of a gear ring according to claim 1, characterized in that, The heat preservation time in step 2) should be controlled between 3 and 4 hours.

4. The inner tooth profile rolling ring forming process of a gear ring according to claim 1, characterized in that, In step 5), the hole is expanded using a pre-expanding core roller so that the inner diameter of the annular blank minus the outer diameter of the planetary gear tooth tool is ≤200 mm.

5. The inner tooth profile rolling ring forming process of a gear ring according to claim 1, characterized in that, In step 5), the holding time for reheating in the furnace should be controlled between 2 and 3 hours.

6. The inner tooth profile rolling ring forming process of a gear ring according to claim 1, characterized in that, The ratio of the weight of the milled toothed ring to the weight of the original blank is ≥0.

97.

7. A tooth profile rolling process for forming a gear ring according to any one of claims 1 to 6, characterized in that, The core roller in step 7) and the core roller with planetary gear in step 8) are the same core roller. The upper part is used to roll the ring of the re-expanded annular billet, and the lower part of the planetary gear is used to roll the teeth of the inner hole of the final expanded annular billet.

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