Special tooth root digging and gear shaping method
By calculating gear meshing parameters and using a single tooth root insertion method, efficient and low-cost tooth root machining was achieved, solving the problem of high production costs for high-precision carburized tooth surface hardened gears.
Patent Information
- Application Number
- CN202510884957.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-30
- Publication Date
- 2025-11-14
AI Technical Summary
In the existing technology, the production cost of high-precision carburized tooth surface hardened gears is high, mainly because the special grinding and root-cutting hobs have narrow adaptability and are expensive.
A special tooth root cutting and shaping method is adopted. By calculating the involute meshing starting circle and tooth groove width of the gear, the single tooth root cutting method is used. The cutting tool is aligned with the center of the tooth groove and the tooth root is inserted. The cutting tool is stopped when the tooth root circle diameter df=(Z-2.5)m. This method replaces the special grinding and cutting hob.
It reduces production costs, improves operational convenience and production efficiency, and solves the problems of narrow adaptability and high price of special grinding and root-cutting hobs.
Smart Images
Figure CN120940750A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a special method for tooth root hollowing and tooth insertion. Background Technology
[0002] In gear design and manufacturing, high-precision carburized and surface-hardened gear hobbing cutters employ pre-cutting hobbing cutters that leave the tooth root unground. These cutters perform "multiple cuts" at the tooth root during hobbing, ensuring the root directly reaches the designed dimensions. After carburizing and quenching, the tooth root is not ground during surface grinding, resulting in compressive stress at the root and significantly higher mechanical strength compared to gears with ground roots. However, the complex calculation of root dimensions and the single-tool requirement limit the production cost of gears without root grinding. Summary of the Invention
[0003] To solve the above-mentioned technical problems, the present invention provides a special tooth root hollowing and tooth insertion method that is easy to operate and low in cost.
[0004] The technical solution of this invention to solve the above-mentioned technical problems is: a special tooth root hollowing and tooth insertion method, comprising the following steps:
[0005] Step 1: Calculate the involute meshing starting circles dnf1 and dnf2 of the two gears using the number of teeth Z, module m, pressure angle α, and installation center distance a of the paired meshing gears;
[0006] Step 2: Calculate the tooth space width K at the starting circle dnf of the gear according to the standard calculation formula;
[0007] Step 3: Once the value of K is determined, use the single tooth root insertion method. The width of the inserter is equal to the tooth groove width K. Align the inserter with the center of the tooth groove of the standard ground gear and insert the tooth root. Stop inserting when the tooth root diameter df = (Z-2.5)m.
[0008] In the aforementioned special tooth root hollowing and tooth insertion method, in step three, the width of the inserting tool ranges from 0.70m to 0.78m, the diameter of the cutter head arc is 0.5m, and the cutting tool length is ≥2.25m.
[0009] In the aforementioned specialized tooth root cutting and inserting method, step three involves the following specific process: The cutting tool is mounted on the spindle of the cutting machine, the gear to be cut is mounted on the indexing plate, and the indexing plate is mounted on a rotary table, ensuring that the axis of the gear to be cut, the axis of rotation of the indexing plate, and the axis of rotation of the rotary table are coaxial. The cutting tool enters one tooth groove of the gear to be cut. When the cutting tool is pressed against the tooth surfaces on both sides of the groove, the gear to be cut automatically rotates and aligns with the cutting tool. Then, the gear to be cut is fixed, and the tooth root is inserted. After inserting one tooth groove, the next tooth groove is inserted through the indexing plate, and this cycle continues until all tooth grooves are inserted.
[0010] The beneficial effects of this invention are as follows: First, the involute meshing starting circle of the two gears is calculated. Then, the tooth groove width K at the starting circle of the gear is calculated. Once the value of K is determined, the single tooth root insertion method is adopted. The cutting tool is aligned with the center of the tooth groove of the standard pre-ground gear and inserted into the tooth root. The cutting tool is stopped when the tooth root circle diameter df = (Z-2.5)m. The special tooth root cutting method is used to replace the special pre-ground gear cutting hob, which solves the problems of the narrow adaptability of the special pre-ground gear cutting hob (a single tool can only adapt to the technical requirements of one type of pre-ground gear) and high price and cost. Attached Figure Description
[0011] Figure 1 A schematic diagram of leaving a toothed shape for the root.
[0012] Figure 2 This is a flowchart of the present invention.
[0013] Figure 3 This is a schematic diagram of a single tooth root.
[0014] Figure 4 This is a schematic diagram of a knife insertion device.
[0015] Figure 5 This is a schematic diagram showing the insert fitting tightly against the tooth surfaces on both sides of the tooth groove.
[0016] Figure 6 This is a schematic diagram showing the automatic rotation of the gear to be inserted and its alignment with the cutting tool. Detailed Implementation
[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0018] like Figures 2-6 As shown, a special tooth root hollowing and tooth insertion method includes the following steps:
[0019] Step 1: Calculate the involute meshing starting circles dnf1 and dnf2 of the two gears using the number of teeth Z, module m, pressure angle α, and installation center distance a of the paired meshing gears;
[0020] Step 2: Calculate the tooth space width K at the starting circle dnf of the gear according to the standard calculation formula;
[0021] Step 3: Once the value of K is determined, use the single tooth root insertion method. The cutter width k is equal to the tooth groove width K. Align the cutter with the center of the tooth groove of the standard ground gear and insert the tooth root. Stop inserting when the tooth root diameter df = (Z-2.5)m.
[0022] like Figure 4 As shown, the width k of the cutting tool ranges from 0.70m to 0.78m, the diameter of the cutting tip arc is 0.5m, and the cutting tool length L is ≥ 2.25m.
[0023] The specific process of gear root shaping is as follows: The shaping tool is mounted on the spindle of the shaping machine, the gear to be shaped is mounted on the indexing plate, and the indexing plate is mounted on the rotary table, ensuring that the axis of the gear to be shaped, the axis of rotation of the indexing plate, and the axis of rotation of the rotary table are coaxial; the shaping tool enters one tooth groove of the gear to be shaped, and when the shaping tool is in close contact with the tooth surfaces on both sides of the tooth groove (e.g., ... Figure 5 When the gear to be inserted rotates automatically and aligns with the cutting tool (e.g.) Figure 6 Then fix the gear to be inserted and insert the tooth root; after inserting one tooth groove, insert the next tooth groove through the indexing plate, and continue the cycle until all tooth grooves are inserted; if a CNC slotting machine and a CNC indexing plate are linked for CNC control, the efficiency will be significantly improved.
Claims
1. A special method for tooth root extraction and tooth insertion, characterized in that, Includes the following steps: Step 1: Calculate the involute meshing starting circles dnf1 and dnf2 of the two gears using the number of teeth Z, module m, pressure angle α, and installation center distance a of the paired meshing gears; Step 2: Calculate the tooth space width K at the starting circle dnf of the gear according to the standard calculation formula; Step 3: Once the value of K is determined, use the single tooth root insertion method. The width of the inserter is equal to the tooth groove width K. Align the inserter with the center of the tooth groove of the standard ground gear and insert the tooth root. Stop inserting when the tooth root diameter df = (Z-2.5)m.
2. The special tooth root hollowing and tooth insertion method according to claim 1, characterized in that, In step three, the width of the insert tool ranges from 0.70m to 0.78m, the diameter of the cutter head arc is 0.5m, and the cutting tool length is ≥2.25m.
3. The special tooth root hollowing and tooth insertion method according to claim 1, characterized in that, In step three, the specific process of inserting the tooth root is as follows: the inserter is installed on the spindle of the inserter, the gear to be inserted is installed on the indexing plate, and the indexing plate is installed on the rotary table, ensuring that the axis of the gear to be inserted, the axis of rotation of the indexing plate, and the axis of rotation of the rotary table are coaxial; the inserter enters one tooth groove of the gear to be inserted, and when the inserter is close to the tooth surfaces on both sides of the tooth groove, the gear to be inserted automatically rotates and aligns with the inserter, and then the gear to be inserted is fixed to insert the tooth root; after inserting one tooth groove, the next tooth groove is inserted through the indexing plate, and the cycle continues until all tooth grooves are inserted.