Sintered Gear Compaction with Radial Clamping
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Solution Overview
Problem
Existing methods for manufacturing gear wheels, particularly helical gears, face challenges in achieving sufficient compaction and preventing springback at the tooth ends, leading to reduced gearing quality and increased hard finishing due to elastic deformation and poor wear resistance.
Innovation Solution
A method involving a clamping device that radially clamps gear wheel blanks over their entire circumference, using a rotating tool with a counter-toothing to compact the toothing area, ensuring each tooth is supported over its entire height, thereby reducing elastic deformation and improving rigidity and toothing quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the gear wheel blank is compacted using a pressing tool in the form of a gear wheel, then the wear resistance and permissible load capacity are improved, but the tooth ends experience elastic deformation and springback leading to reduced gearing quality
Solution Approach 1:
The patent applies preliminary action by providing additional material allowance on the tooth flanks before the compaction process. This allowance compensates for the elastic deformation and springback that occur during compaction, ensuring that the final tooth geometry meets the required precision standards after the pressing tool has compacted the material.
Solution Approach 2:
The patent changes the material distribution parameter by introducing an asymmetric allowance that is specifically larger at the tooth ends where elastic deformation occurs. This parameter change ensures that even after compaction-induced springback, the tooth flanks maintain the correct geometry and gearing quality.
2Strength
If the gear wheel blank is compacted to increase flexural strength at tooth roots, then the load capacity is improved, but the tooth ends twist and require additional hard finishing
Solution Approach 1:
The patent applies preliminary action by pre-shaping the tooth flanks with additional material allowance before compaction. This preliminary material distribution compensates for the twisting and deformation that will occur during compaction, reducing or eliminating the need for subsequent hard finishing operations.
Solution Approach 2:
The patent converts the harmful effect of compaction-induced tooth end twisting into a benefit by intentionally designing the allowance distribution to anticipate and compensate for this deformation. The harmful springback is transformed into a predictable geometric change that can be pre-corrected through intelligent material distribution.
3Reliability
If the gear wheel blank is compacted using a rotating tool, then the surface layer becomes largely pore-free, but the tooth ends cannot be sufficiently supported to prevent springback
Solution Approach 1:
The patent changes the material distribution parameter by introducing an asymmetric allowance that is specifically larger at the tooth ends where support is needed. This parameter change ensures that the tooth ends have sufficient material to resist springback while the rotating tool creates a pore-free surface layer through compaction.
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 enhances the rigidity of the tooth ends, reduces elastic deformation, and improves the toothing quality of gear wheels, particularly helical gears, by ensuring comprehensive support during compaction, thus addressing the limitations of existing methods.
Implementation Method 1
compacting the gear wheel blank in the area of the allowance by engaging at least one rotating tool with a counter-toothing engaging in the toothing of the gear wheel blank
Implementation Method 2
the gear wheel blank is radially clamped on both end faces by the clamping means over the circumference during its compaction, each individual tooth of the toothing of the gear blank being supported by the clamping means substantially over the entire tooth height
Data Source
Figure 1~2
Figure 3~4
Figure 5a~6c
AI summary
The invention relates to a method for producing at least one gear, in particular a helically toothed gear, wherein the gear is produced from a gear blank (20, 38, 50, 52, 62, 72, 80, 82, 84) pressed and sintered with an oversize in the region of the set of teeth (18), wherein the gear blank (20, 38, 50, 52, 62, 72, 80, 82, 84) has two opposite end faces and a circumference. In the method, the gear blank (20, 38, 50, 52, 62, 72, 80, 82, 84) is clamped in a clamping means (42). The gear blank (20, 38, 50, 52, 62, 72, 80, 82, 84) is compressed in the region of the oversize by means of the engagement of at least one circumferential tool (10, 28) having a set of mating teeth (12, 26) that engages with the set of teeth (18) of the gear blank (20, 38, 50, 52, 62, 72, 80, 82, 84), wherein the gear blank (20, 38, 50, 52, 62, 72, 80, 82, 84) is radially clamped over the circumference by the clamping means (42) at both end faces during the compression of the gear blank, wherein each individual tooth (56, 66) of the set of teeth (18) of the gear blank (20, 38, 50, 52, 62, 72, 80, 82, 84) is supported by the clamping means (42) substantially over the entire tooth height. In this way, the quality of the set of teeth can be improved. The invention further relates to a device and to a clamping means.