Sintered Gear Tooth Rolling With Center-Density Pressing
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Solution Overview
Problem
During rolling processing of gear raw materials, the density decrease near the center of tooth parts can lead to cracks, as material flows to the tip and bottom sides, reducing the density and potentially causing fractures.
Innovation Solution
A method where the gear raw material is pressed by a pressing machine towards its center thickness, focusing on regions with decreased internal density during rolling, using a pressing force applied on both sides to prevent cracks by reducing the depth of pressing and ensuring the region of low density is locally addressed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If rolling processing is performed on the tooth parts of the gear raw material to densify the tooth surface, then the tooth surface density is improved, but the density in the vicinity of the center position of the tooth height decreases and cracks may occur
Solution Approach 1:
The pressing machine performs preliminary pressing on the gear raw material before rolling processing to pre-densify the center region. This preliminary action prevents density decrease and crack formation during subsequent rolling by already establishing adequate density in the vulnerable center area before the rolling load is applied.
Solution Approach 2:
The pressing machine applies a counteracting force to prevent the harmful effect of density decrease. By pressing the gear raw material toward the center of thickness, it creates a compensating densification effect that counteracts the material flow to tip and bottom sides during rolling, thereby preventing crack formation.
2Ease of manufacture
If pressing force is applied from one side of the gear raw material, then the pressing operation is simpler, but the depth of pressing is greater and may cause excessive deformation
Solution Approach 1:
The pressing operation uses asymmetric positioning of pressing points on both sides of the gear raw material, targeted at the center region. This asymmetric approach allows distributed pressing force that achieves precise depth control while maintaining operational simplicity through automated positioning.
Solution Approach 2:
The pressing force is segmented and applied from multiple sides (both sides of the gear raw material) rather than as a single concentrated force. This segmentation distributes the pressing load, enabling better control of pressing depth while maintaining the simplicity of the pressing operation through standardized pressing mechanisms.
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 method effectively prevents cracks in tooth parts during rolling processing by maintaining density and reducing the risk of fractures, allowing for more controlled and efficient gear manufacturing.
Implementation Method 1
pressing the gear raw material toward a center of a thickness thereof by a pressing machine
Implementation Method 2
rolling processing is performed on a sintered gear raw material to densify a tooth surface density
Data Source
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AI summary
A method for manufacturing a gear which effectively prevent a crack from occurring inside a tooth part when rolling processing is performed on a teeth part of a gear raw material is achieved. A method according to one embodiment for manufacturing a gear 15 by performing rolling processing on a tooth part 2a of a sintered gear raw material 2. The method includes, when the rolling processing is performed on the tooth part 2a of the gear raw material 2, pressing the gear raw material 2 toward a center of rotation of the gear raw material 2 by a rolling machine 4 and, when at least the rolling processing is performed on the tooth part 2a of the gear raw material 2 toward a center of a thickness thereof by a pressing machine 5, pressing a region A where an internal density of the tooth part 2a of the gear raw material 2 decreases. The invention also relates to an apparatus for manufacturing a gear.