Bicycle Front Fork Upper Tube Recesses for Bushing Lubrication
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Solution Overview
Problem
Suspension forks in bicycles experience increased friction at the interface between upper tubes and bushings, leading to harsh riding feedback due to insufficient lubrication, which affects damping force and overall riding comfort.
Innovation Solution
Incorporation of recesses, dimples, or cavities on the outer surface of the upper tube to collect and distribute lubricating oil to the interface between the upper and lower tubes, ensuring continuous lubrication and reducing friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the upper tube and bushing interface relies on passive lubrication from oil volume in the lower tube, then the device structure remains simple, but lubrication is insufficient leading to increased friction and harsh riding feedback
Solution Approach 1:
The recesses are pre-formed on the outer surface of the upper tube to collect and store lubricating oil in advance. When the suspension fork compresses, these recesses automatically pick up oil and transport it to the bushing interface, ensuring lubrication is delivered before friction becomes problematic.
Solution Approach 2:
Instead of uniformly distributing oil throughout the entire lower tube, the invention creates localized oil collection features (recesses) at specific positions on the upper tube surface. These recesses are strategically positioned to intercept and deliver oil precisely where the bushing interface requires lubrication, improving effectiveness without adding overall system complexity.
2Ease of operation
If lubricating oil is simply contained in the lower tube interior region, then the device structure remains simple, but the oil does not effectively reach the bushing interface causing increased friction
Solution Approach 1:
The recesses act as intermediary structures between the oil reservoir (lower tube interior) and the bushing interface. They collect oil from the interior region and serve as transport vehicles, carrying the lubricant to the specific location where it is needed, thereby facilitating smooth telescopic movement without complex pumping or delivery mechanisms.
3Duration of action of moving object
If the upper tube moves repeatedly between extended and contracted positions, then the telescopic function is achieved, but friction at the bushing interface increases over time degrading performance
Solution Approach 1:
The recesses enable continuous lubrication delivery throughout the telescopic cycle. As the upper tube moves between extended and contracted positions, the recesses repeatedly collect and deliver oil to the bushing interface, ensuring uninterrupted lubrication that maintains smooth operation and extends service life without requiring complex periodic maintenance systems.
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 continuous lubrication to the bushing interface, enhancing the smoothness of the telescopic movement and improving the riding experience by mitigating frictional effects over time.
Implementation Method 1
The recess is to collect an amount of oil when the upper tube is moved into the lower tube
Implementation Method 2
The upper tube is to have sliding contact with the bushing... The recess is to distribute the amount of oil to the bushing when the upper and lower tubes are moved toward the fully extended position
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
Bicycle front forks having features to distribute lubricant are disclosed herein. An example front fork (200) includes a lower tube (208) having a first top end (306) and a first bottom end (308), the lower tube (208) defining an interior region (312) to contain a volume of oil (302), a bushing (332, 334) coupled to an inner surface (314) of the lower tube (208), and an upper tube (204) having a second top end (303) and a second bottom end (304) opposite the second top end (303), the second bottom end (304) disposed in the lower tube (208), the upper tube (204) in sliding contact with the bushing (332, 334), the upper and lower tubes (204, 208) arranged in a telescopic arrangement and moveable between a fully extended and a fully contracted position, the upper tube (204) having a recess (344, 908), the recess (344, 908) to collect oil (302) when the upper tube (204) is moved into the lower tube (208) and distribute the oil (302) to the bushing (332, 334) when the tubes (204, 208) are moved toward the fully extended position.