Gear Shaping Contact Track Angle to Reduce Tool Wear
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Solution Overview
Problem
Gear shaping methods face challenges with high tool loads and increased risk of damage, especially with high stroke numbers and small helix angles, leading to tool wear and inefficient machining.
Innovation Solution
The method involves adjusting the contact track angle on the workpiece to be γ, where cotangent γ is less than or equal to a product of constants K1 and K2, with K1 being 40 or lower, and K2 depending on geometry and process factors, allowing for extended contact tracks in the vertical direction and uniform feed across tooth flanks, reducing tool stress and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional gear shaping with contact tracks running parallel to flank line is used, then machining speed can be maintained, but tool wear increases and process safety decreases due to concentrated stress on cutting edge points
Solution Approach 1:
The invention changes the orientation parameter of contact tracks by adjusting the angle γ between contact tracks and flank lines. By setting cotangent γ ≤ K1·K2 (where K1=40 and K2 is a geometry/process factor), the contact tracks are oriented at an optimal angle rather than parallel to the flank line, distributing cutting forces more evenly across the cutting edge and reducing concentrated stress, thereby improving process safety while maintaining machining speed
2Productivity
If higher stroke numbers are used to increase productivity, then machining speed increases, but tool loads become excessively high leading to increased risk of damage and tool wear
Solution Approach 1:
The invention changes the contact track orientation parameter (angle γ) to redistribute cutting forces. By orienting contact tracks at an angle where cotangent γ ≤ K1·K2, the cutting forces are distributed more uniformly across multiple points of the cutting edge rather than being concentrated, allowing higher stroke numbers to be used without excessively high tool loads, thus increasing productivity while controlling tool loads
3Device complexity
If contact tracks run parallel to flank line, then machining process is simple, but chip formation causes compression and concentrated stress leading to increased tool wear
Solution Approach 1:
The invention modifies the contact track orientation parameter by setting angle γ such that cotangent γ ≤ K1·K2. This parameter change alters the chip formation pattern from compressed chips to more favorably oriented chips, reducing concentrated stress on cutting edge points and minimizing tool wear, while the adjustment can be implemented through existing machine parameters without significantly increasing process complexity
Data Source
AI summary
The invention relates to a method for gear shaping a toothing (55) with a specified normal pitch (mn), angle of action (α), and optionally a helix angle (β) on a workpiece (50), wherein a shaper cutter (40) moving in stroke cycles with a specified stroke length (h) removes material from the workpiece in multiple working strokes in a rolling machining engagement, thereby forming contact tracks, wherein the contact track on the partial circle in the stroke center runs at an angle (γ) to the flank line (57) at least for a first plurality of strokes, the cotangent of said angle being smaller than or equal to the product of a constant of 40, preferably 33, in particular 25, and a geometry/process factor.