Elastomeric Gear Hub for Vibration Damping and Backlash Reduction
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Solution Overview
Problem
Spur gear drives with high torsional vibration and shaft deflection face challenges in maintaining no-play positioning of meshing teeth, leading to increased axial tolerance and noise emission.
Innovation Solution
A tolerance compensating element with a shaft part and a compensating part made from rubber elastic material is used, connected to the main gear via a positively bonded or fitting connection, to absorb vibrations and deflections, reducing axial tolerance and circumferential backlash.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard rigid connections are used in spur gear drives, then manufacturing precision can be maintained, but the gear assembly cannot cope with high torsional vibration and shaft deflection
Solution Approach 1:
The patent changes the physical state of the connection between gear and shaft from rigid to elastic by using an elastomeric material. This allows the connection to dynamically adapt to torsional vibrations and shaft deflections while maintaining acceptable manufacturing tolerances of ±0.5 mm, which would be impossible with rigid connections.
Solution Approach 2:
The patent employs a composite structure where an elastomeric material is used to create the hub part connecting the gear to the shaft. This elastomeric material combines flexibility to handle vibrations with sufficient strength to transmit torque, resolving the contradiction between reliability under dynamic loads and manufacturing precision.
2Reliability
If larger axial tolerance is allowed to accommodate vibrations, then reliability improves, but circumferential backlash increases
Solution Approach 1:
The elastomeric hub part provides dynamic compliance that allows the gear to move with the shaft during vibrations while maintaining tooth engagement. This dynamic adaptation prevents the development of circumferential backlash even when accommodating larger axial tolerances for vibration handling.
Solution Approach 2:
By changing the connection from rigid to elastic, the system can accommodate axial movements due to vibrations without translating these movements into circumferential backlash. The elastomeric material absorbs the dynamic displacements while maintaining the gear mesh geometry.
3Manufacturing precision
If rigid gear assembly is used, then manufacturing precision is maintained, but noise emission increases
Solution Approach 1:
The patent converts the potential harm of larger tolerances and vibrations into a benefit by using the elastomeric material to dampen vibrations and reduce noise. The flexibility that would seem to compromise precision actually reduces noise emission by preventing rigid impacts and vibrations during operation.
4Reliability
If elastomeric material is used for compensating part, then vibration damping improves, but connection strength may be compromised
Solution Approach 1:
The elastomeric hub part is designed as a composite structure that combines the vibration-damping properties of elastomeric materials with sufficient structural integrity. The material selection and geometric design ensure that connection strength is maintained while achieving superior vibration damping compared to rigid materials.
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 solution effectively compensates and damps torsional vibrations, reduces noise, and enhances the meshing engagement of gear teeth, allowing for higher axial tolerance and improved operational performance.
Implementation Method 1
the compensating part is made at least partially from a rubber elastic material
Implementation Method 2
due to the elastic properties of the compensating part, torsional vibrations and deflections of the shaft can be better compensated and damped
Data Source
AI summary
The invention relates to a device (4) for positioning meshing teeth (3, 8, 9) of a gear drive without any play, comprising a gear assembly (5), which gear assembly (5) comprises a main gear (6) having first teeth (8) and a gear (7) that is rotatable relative thereto in the circumferential direction having second teeth (9), and the main gear (6) comprises a hub part (10) on which the rotatable gear (7) is disposed, and a tolerance compensating element (12) comprising a shaft part (13) and a compensating part (14) is disposed radially underneath the main gear (6), and the compensating part (14) is connected to the shaft part (13) and to the hub part (10) of the main gear (6) so that the main gear (6) is connected exclusively via the compensating part (14) to the shaft part (13), and the compensating part (14) is made at least partially from a rubber elastic material.