Thin-Walled Ring Gear Forming With Synchronized Dual Toothing
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Solution Overview
Problem
Current methods for producing internal impeller gear teeth in ring gears face challenges such as high weight due to thick-walled designs, difficulty in achieving lightweight components, and limitations in manufacturing accuracy and efficiency, particularly in cold-forming processes which struggle with the complexity and precision required for impeller gears.
Innovation Solution
A method and device that simultaneously form internal and external impeller gear teeth using a die with internal teeth, where a workpiece is stabilized and processed with an embossing tool to create both toothings in a single process, allowing for precise formation of impeller teeth with reduced material thickness and enhanced dimensional stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If thick-walled designs are used for internal gears, then dimensional stability is improved, but weight increases
Solution Approach 1:
The patent applies local quality by varying the wall thickness distribution in the ring gear. The wall thickness is reduced in specific regions where structural support is provided by the gear teeth and stabilizing sections, while maintaining sufficient thickness in areas requiring dimensional stability. This allows the gear to achieve lightweight construction without compromising overall stability.
Solution Approach 2:
The patent segments the ring gear structure by introducing stabilizing sections that divide the gear body into distinct functional zones. These stabilizing sections provide localized structural support, enabling thinner walls in other areas. The segmentation allows the gear to maintain dimensional stability through strategically placed reinforcement rather than uniform thick-walled construction.
2Weight of moving object
If remaining wall thickness is reduced for weight savings, then weight decreases, but manufacturability and dimensional stability deteriorate
Solution Approach 1:
The patent employs preliminary action by forming stabilizing sections and gear tooth profiles simultaneously during the cold forming process, before final assembly. The embossing tools create the internal gear teeth and stabilizing sections in a single operation, ensuring that thin-walled structures are formed with proper structural support built-in from the outset, eliminating the need for subsequent reinforcement or assembly operations.
Solution Approach 2:
The patent uses embossing tools as intermediaries to transfer the gear tooth profile from a mandrel to the ring gear blank. These tools enable precise formation of thin-walled gear teeth with complex geometries that would be difficult to achieve with direct machining, while the stabilizing sections act as intermediaries to maintain structural integrity during the forming process.
3Productivity
If cold-forming processes are used for internal impeller gears, then manufacturing efficiency is improved, but manufacturing accuracy deteriorates
Solution Approach 1:
The patent employs copying by using an externally profiled mandrel that defines the precise gear tooth geometry. The embossing tools replicate this profile from the mandrel onto the ring gear blank during cold forming. This copying mechanism ensures high manufacturing accuracy is achieved through the mandrel's precise geometry, while the cold-forming process itself maintains high productivity by forming multiple teeth simultaneously.
Solution Approach 2:
The patent uses periodic action through the oscillating movement of embossing tools that repeatedly impact the ring gear blank during rotation. This periodic forming action allows the gradual development of complex gear tooth profiles with high precision, while maintaining efficient production through continuous rotation and periodic tool engagement rather than sequential operations.
4Strength
If multiple joining steps are used for pot-shaped workpieces, then structural integrity is improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges the formation of the gear tooth profile and the stabilizing sections into a single cold-forming operation. The embossing tools simultaneously create both features from the ring gear blank, eliminating the need for separate joining steps to attach stabilizing elements. This combining of operations maintains structural integrity through integrated design while reducing manufacturing complexity by eliminating multiple assembly steps.
Solution Approach 2:
The patent applies preliminary action by forming all structural features including stabilizing sections and gear teeth in a single preliminary cold-forming operation, before any assembly or joining operations. This ensures structural integrity is built-in from the outset through integrated forming, eliminating the need for subsequent joining steps to achieve structural completeness.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in a lightweight ring gear with high manufacturing accuracy and efficiency, achieving quality impeller gearing with reduced weight and processing time, while maintaining sufficient dimensional stability for mechanical applications.
Implementation Method 1
The hollow gear is produced by cold forming through a hammering action of an embossing tool, which forms the workpiece into the die teeth
Implementation Method 2
The material of the tubular section is shaped by machining with at least one embossing tool and formed into the tooth gaps of the die teeth
Data Source
Figure 1~3d
Figure 2a~2b
Figure 4~7b
AI summary
The invention relates to a method for producing a ring gear which has inner toothing and outer toothing, the inner toothing being toothing for driving a pinion. In the method, a workpiece (1) is machined by a stamping tool (2). The workpiece (1) has a tubular section (3) with a longitudinal axis (Z) and a first stabilisation section (4) for stabilising the shape of the tubular section (3) during machining. The tubular section (3) is inserted into a die (5) which has inner die toothing (5z). The workpiece (1) is then machined on the inside by the stamping tool (2) to produce the inner toothing and the outer toothing simultaneously, in that the workpiece executes a rotational movement at a time-variable rotation speed, and the stamping tool (2) executes radially oscillating movements which are synchronised with said rotational movement. In the process, the stamping tool (2) shapes the tubular section (3) to produce the outer toothing while at the same time producing the inner toothing by repeated hammering of the tubular section (3) into the die toothing (5z).