Elastic Centering Elements in Toothed Sprocket Hubs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Low-cost manufacturing methods for toothed sprockets with hub gears result in inadequate centering, leading to wobbling and noise issues due to large manufacturing tolerances, which conventional methods struggle to address effectively.
Innovation Solution
Incorporation of elastic centering elements, specifically radially movable bending beams, that deform to achieve precise centering and absorb manufacturing tolerances, ensuring accurate alignment and torque transmission without the need for close tolerances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If low-cost manufacturing methods (sintering, casting, stamping) are used for toothed sprockets, then manufacturing cost is reduced, but manufacturing precision deteriorates due to large tolerances (plus/minus 0.15 millimeters)
Solution Approach 1:
The patent changes the physical state and mechanical properties of the sprocket by introducing elastic centering elements that can deform radially. These elements allow the sprocket to adapt its dimensional parameters dynamically, compensating for the large tolerances inherent in low-cost manufacturing methods without requiring precise bore dimensions.
Solution Approach 2:
The invention introduces dynamic elements (elastic centering components, bending beams) that can move and deform to accommodate tolerance variations. Instead of relying on static precise fits, the system uses dynamic adjustment through elastic deformation to achieve proper centering and eliminate play between the sprocket and hub gear.
2Ease of operation
If clearance fit is used between sprocket and input shaft, then ease of assembly is improved, but stability deteriorates due to wobbling and axial movement
Solution Approach 1:
The patent introduces elastic centering elements as intermediary components between the sprocket and the input shaft. These intermediaries absorb the clearance fit while providing positive centering through radial deformation, acting as a mediator that reconciles the conflicting requirements of easy assembly and stable positioning.
Solution Approach 2:
The invention segments the centering function from the main sprocket body by using separate elastic centering elements. This segmentation allows the centering mechanism to independently compensate for tolerances and provide stability without affecting the overall clearance fit design, enabling the sprocket to maintain both ease of assembly and operational stability.
3Manufacturing precision
If multiple elastic surfaces are arranged in the hub bore, then manufacturing precision is improved through tolerance absorption, but device complexity increases
Solution Approach 1:
The patent employs flexible elastic centering elements that function similarly to flexible shells or films. These elements can deform radially to absorb tolerance variations, providing precise centering through their elastic properties rather than through complex rigid mechanical adjustments, thereby reducing overall structural complexity.
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
The solution provides reliable centering and reduced noise by absorbing manufacturing tolerances, enhancing the durability and reducing manufacturing costs through fewer and less stringent tolerance requirements.
Implementation Method 1
at least two elastic centering elements (14) are arranged inside the bore (9) which are deformable in the radial direction
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A toothed sprocket hub with elastic centering element comprising an input shaft (2) having a receiving portion (5) and a cylindrical outer surface (16), a sprocket (7) engagable with the input shaft, the sprocket comprising at least two first surfaces (12) each disposed on a bending beam (14) such that each first surface is elastically moveable in a radial direction, the two first surfaces bearing upon the outer surface, the two first surfaces each having a radius d that is less than a radius D of the outer surface, at least one second surface (13) that is radially moveable to a lesser extent than a first surface, the second surface engaging the receiving portion to prevent a relative rotation of the sprocket with the input shaft, and a third surface (17) in cooperative relation to the second surface, the third surface bearing upon the outer surface of the input shaft, the third surface having a clearance fit with the outer surface.