Worm Gear Tooth Layout for Rotational Balance and Easier Machining
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Solution Overview
Problem
The existing manufacturing process for worms is complicated by the need to adjust both the lead angle of the teeth and the chamfer angle at both axial ends, which complicates the manufacturing process.
Innovation Solution
A worm design with a main body part, first and second tapered parts, and spiral teeth, where the position of the second tooth bottom end part is configured within an angle range of less than 90 degrees relative to the first tooth bottom end part, centered on the worm's rotation center, to achieve good rotational balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the lead angle of teeth and chamfer angle are adjusted to achieve good rotational balance, then rotational balance is improved, but manufacturing process complexity increases
Solution Approach 1:
The patent applies asymmetry by configuring the second tooth bottom end part at a position within an angle range of less than 90 degrees on another circumferential side with respect to the first tooth bottom end part, centered on the rotation center. This asymmetric arrangement of tooth bottom end parts creates a specific mass distribution that achieves rotational balance without requiring complex adjustments to lead angles or chamfer angles, thereby simplifying the manufacturing process while maintaining good rotational balance
2Stability of the object's composition
If the position of the second tooth bottom end part is configured within an angle range of less than 90 degrees, then rotational balance is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent changes the key parameter from angular positioning (which would require high precision control of lead angle and chamfer angle) to a positional relationship defined by an angle range of less than 90 degrees. This parameter change allows for a more practical manufacturing approach where the exact position within the angle range can be achieved with standard manufacturing tolerances, reducing the precision requirements while still achieving good rotational balance
Data Source
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AI summary
A worm (35) capable of obtaining good rotational balance while simplifying the manufacturing process is provided. A cutting start part (71) forming one end part of a tooth bottom part (74) is provided at a first tapered part (35b). A cutting end part (72) forming another end part of the tooth bottom part (74) is provided at a second tapered part (35c). The tooth bottom part (74) extends to advance in a spiral shape from the cutting start part (71) toward one circumferential side (counterclockwise direction) of the worm (35). A position of the cutting end part (72) is configured within an angle range (at a position of 38 degrees) of less than 90 degrees on another circumferential side (clockwise direction) of the worm (35) with respect to a position of the cutting start part (71), centered on a rotation center of the worm (35).