Gear Chamfering Pitch Ratio to Reduce Cutting Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional chamfering tools for toothed gears face challenges in reducing cutting resistance, leading to a shortened tool life due to the inability to set the circumferential speed of end cutting edges faster than the circumferential speed of the teeth.
Innovation Solution
The method involves forming a toothed gear with a tool that has end cutting edges with a pitch set to M times the pitch of the teeth, where M > 1, and chamfering every N teeth, with N ≥ 1, allowing the circumferential speed of the end cutting edges to exceed the circumferential speed of the teeth, and adjusting the number of end cutting edges to enhance design freedom.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pitch of end cutting edges is set equal to the pitch of teeth, then the circumferential speed of end cutting edges equals the circumferential speed of teeth, but the cutting resistance cannot be reduced and tool life is shortened
Solution Approach 1:
The patent changes the pitch parameter of the end cutting edges from being equal to the tooth pitch to being M times the tooth pitch (where M is an integer greater than 1). This parameter change allows the circumferential speed of the end cutting edges to be M times faster than that of the teeth, reducing cutting resistance and extending tool life while maintaining effective chamfering of all teeth through coordinated rotation.
2Productivity
If the circumferential speed of end cutting edges is increased, then cutting resistance is reduced, but the pitch relationship with teeth becomes incompatible
Solution Approach 1:
The patent introduces dynamic coordination between the tool rotation and workpiece rotation. By setting the pitch ratio as an integer M and coordinating the rotational speeds accordingly, the system dynamically ensures that all teeth are chamfered despite the end cutting edges moving at M times the speed of the teeth. This dynamic approach resolves the pitch relationship incompatibility while maintaining high cutting speed.
3Reliability
If multiple end cutting edges are arranged to chamfer all teeth, then complete chamfering is achieved, but the number of cutting edges is restricted by pitch requirements
Solution Approach 1:
The patent makes the tool universally applicable to different gear configurations by establishing a general pitch relationship where the end cutting edge pitch is M times the tooth pitch (M being any integer greater than 1). This universal relationship, combined with coordinated rotation, allows the same tool design principle to chamfer all teeth regardless of the specific number of teeth or gear geometry, significantly enhancing design freedom and adaptability.
Data Source
AI summary
A method for chamfering toothed gears which enables lengthening of a life of a tool is provided. The chamfering method is for sequentially chamfering the line intersection portions 23 between tooth flanks 21 and end faces 22 of teeth 2 with end cutting edges 122. A pitch Pb of the end cutting edges 122 is set to five times a pitch Pa of the teeth 2. As a result, at a chamfering step of chamfering line intersection portions 23 of the teeth 2, a circumferential speed of the end cutting edges 122 can be made faster than a circumferential speed of the teeth 2. Consequently, a difference in circumferential speed between the end cutting edges 122 and the teeth 2 can be utilized in chamfering and thus a cutting resistance can be reduced during the chamfering. Therefore, a life of the tool 100 can be lengthened.