Continuously Variable Transmission With Intermeshing Needles
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Solution Overview
Problem
Existing continuously variable transmission systems face limitations in torque capability and durability due to frictional contact and the need for hydraulic lubrication in friction cone drives, which leads to wear and deterioration of friction surfaces.
Innovation Solution
A transmission mechanism using conical members with intermeshing needles that transfer torque without physical contact, allowing for variable speed ratios and torque transmission across a wide range by adjusting the angular position of an intermediate cone member, eliminating the need for additional mechanical connectors and lubrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If friction cone drives are used to achieve variable torque range, then torque transmission capability is improved, but friction surface wear and deterioration occur due to sliding motion requiring hydraulic lubrication
Solution Approach 1:
The patent replaces the friction-based mechanical contact system with a needle-based mechanical interlocking system. Needles protruding from the driving cone engage with corresponding recesses in the driven cone, transferring torque through direct mechanical engagement rather than friction. This substitution eliminates the need for hydraulic lubrication and prevents friction surface wear while maintaining high torque transmission capability.
2Reliability
If hydraulic lubricating oil film is used to protect friction surfaces, then wear and galling are reduced, but torque capability is limited and system complexity increases
Solution Approach 1:
The patent eliminates the hydraulic lubrication system entirely by replacing friction-based torque transfer with needle-based mechanical interlocking. The needles physically engage between cones, transferring torque through direct contact and interlocking rather than through a lubricating oil film. This mechanical substitution removes the limitation on torque capability imposed by lubrication while simplifying the system by eliminating hydraulic components.
3Adaptability or versatility
If friction cone drives with sliding motion are used, then variable torque range is achieved, but galling and deterioration of friction surfaces occur
Solution Approach 1:
The patent replaces the sliding friction contact system with a needle interlocking system that maintains variable torque range capability without sliding motion. The needles engage in recesses and can slide within them without causing galling, as the primary torque transfer occurs through the interlocking mechanism rather than surface friction. This eliminates the harmful effects of galling and deterioration while preserving adaptability.
4Power
If additional mechanical connectors and lubrication systems are added to friction cone drives, then torque transmission is improved, but device complexity and weight increase
Solution Approach 1:
The patent extracts and removes the unnecessary components from the transmission system. By using direct needle-to-recess engagement between cones, the invention eliminates the need for additional mechanical connectors (such as couplings or gears) and lubrication systems (hydraulic pumps, reservoirs, and delivery mechanisms). This extraction simplifies the device while maintaining effective torque transmission.
Data Source
AI summary
A continuously variable transmission includes a driving member rotating about a first axis, a driven member rotating about a second axis, and an intermediate member interposed between the driving and driven members and rotating about a third axis configured to intersect the first and second axes. The intermediate member transfers torque from the driving member to the driven member. A method for forming a torque transfer member includes providing a base structure, wrapping a needle assembly around the base structure such that the needles extend outwardly therefrom, and affixing the needle assembly to the base structure. A method of manufacturing a needle assembly includes forming a series of pockets on a side of a ribbon, organizing a series of needles into a series of pockets, and affixing the series of needles into the series of pockets.