Diagonal Gear Cutting for Twist-Free Tooth Flank Crowning
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Solution Overview
Problem
Existing methods for producing workpieces with corrected toothing geometry and modified surface structures often result in shape deviations and unwanted modifications, particularly in helical gears, due to limitations in controlling the direction and orientation of crowning and flank line modifications.
Innovation Solution
A diagonal rolling method using a modified tool with targeted surface geometry modifications, where the tool's surface geometry is altered to produce directional crowning and flank line modifications without shape deviations, allowing for precise control over the direction and orientation of these modifications on the workpiece.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the center distance between the grinding worm and workpiece is changed to create crowned modification, then crowning is achieved, but twisting and shape deviations occur
Solution Approach 1:
The patent controls the center distance variation as a function of position along the worm axis, increasing or decreasing the center distance towards the ends according to the square of the distance from the center. This specific parameter change profile creates the desired crowning modification while eliminating unwanted twisting and shape deviations by precisely controlling the geometric transformation.
2Manufacturing precision
If additional movements are superimposed on the profiling tool and grinding worm to create tooth flank modifications, then the modifications are reflected on the gear flanks, but the process complexity increases
Solution Approach 1:
The patent implements preliminary action by pre-configuring the grinding worm surface geometry with the desired modification patterns before the gear cutting process. Instead of adding complex additional movements during machining, the modifications are built into the worm itself through controlled center distance variations during dressing, simplifying the actual machining process while achieving the desired tooth flank modifications.
3Manufacturing precision
If the position of the dresser for tool dressing is varied to generate surface geometry modification, then the tool modification produces corresponding workpiece modification, but control precision requirements increase
Solution Approach 1:
The patent transforms the control problem from requiring high-precision dresser position control to controlling center distance variations, which are easier to measure and control. By changing the parameter being controlled (from dresser position to center distance), the system achieves the same surface geometry modification with reduced measurement precision requirements while maintaining manufacturing precision.
Data Source
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AI summary
The present invention shows a method for producing a workpiece with a corrected toothing geometry and/or modified surface structure by means of a diagonal rolling process using a modified tool, with a targeted modification of the surface geometry of the tool being produced, with the modification of the tool by the diagonal rolling process producing a corresponding modification on the generated surface of the workpiece. The targeted modification on the surface of the workpiece is a directed crowning without shape deviations, a pure flank line modification and/or an end relief and/or where the lines of constant modification on the workpiece run at an angle of less than 60° to the line of action of the toothing.