Barrel-Shaped Threaded Tool for Internal Gear Machining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional internal gear grinding methods face challenges in achieving high accuracy due to the need to adjust the helix angle of the threaded grinding wheel, which is difficult to set accurately given the barrel shape's varying dimensions and contact points along its length.
Innovation Solution
A barrel-shaped threaded tool with a gradually decreasing diameter from the intermediate to the end portions, where the helix angle is set in accordance with the length from the intermediate portion, allowing for a controlled change in the helix angle to ensure precise meshing and machining accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a fixed helix angle is given to the threads of the barrel-shaped threaded tool, then the tool structure is simple, but the machining accuracy decreases because the contact point between thread and tooth varies along the axial length
Solution Approach 1:
The patent applies local quality by making the helix angle variable along the axial length of the barrel-shaped threaded tool. Specifically, the helix angle is set to be larger at the axially intermediate portion and smaller at the axially opposite end portions, with the rate of change being larger at the intermediate portion and smaller at the end portions. This localized variation in geometric parameters ensures that the contact point between the thread and tooth remains consistent along the axial direction, thereby achieving high machining accuracy without requiring complex adjustable mechanisms.
2Manufacturing precision
If the helix angle is changed to maintain consistent contact points, then machining accuracy is improved, but the difficulty of manufacture increases due to the complex variable geometry
Solution Approach 1:
The patent applies parameter changes by systematically varying the helix angle as a function of axial position along the barrel-shaped tool. The helix angle is designed to change continuously, being larger at the axially intermediate portion and smaller at the axially opposite end portions. This controlled parameter variation ensures consistent contact points between thread and tooth during machining, achieving high accuracy while the gradual change pattern facilitates manufacturing through conventional machining methods.
Data Source
AI summary
An object is to provide a barrel-shaped threaded tool for machining an internal gear which is capable of machining with high accuracy by appropriately setting a helix angle. To achieve the object, in a threaded grinding wheel (11) formed into a barrel shape having a diameter gradually decreasing from an axially intermediate portion thereof toward axially opposite end portions thereof so that the threaded grinding wheel (11) is meshed with a workpiece (W) with a crossed axes angle (Σ) therebetween during the machining of the workpiece (W), the helix angle is set in accordance with the length from the axially intermediate portion.