Frustoconical Chain CVT Layout for Low-Vibration Torque Transfer

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Solution Overview

Problem

Existing continuously variable transmissions face challenges such as high friction, wear, vibration, and inefficiency due to uneven chain support and shifting issues, particularly under high torque and power transfer conditions.

Innovation Solution

The design incorporates a pair of frustoconical members on each axle with radially extending guide railing slots, allowing for axial sliding to adjust the chain tension and maintain constant engagement with unidirectional sprocket wheels, thereby reducing vibration and improving efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If friction-based continuously variable transmissions use conical components with movable belts, then power transmission is achieved, but sudden slipping occurs causing uncertain power transmission and large wear

Engineering Contradiction:

Improvepower transmission reliabilityVSAvoidpower loss due to slipping

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces friction-based mechanical power transmission with a positive engagement chain drive system. The chain engages with sprocket teeth to transmit power without relying on friction, eliminating slipping and associated power losses while maintaining reliable power transmission under high torque conditions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the fundamental transmission mechanism from friction-dependent to positive engagement. By altering the interaction mode between transmitting elements (from friction contact to tooth-chain engagement), the system achieves reliable power transmission without the energy losses inherent in friction-based systems.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If multiple fixed gear ratios are provided in conventional transmissions, then power transfer is achieved, but optimal transmission ratio cannot be maintained as vehicle speed changes, causing increases in power use and fuel consumption

Engineering Contradiction:

Improvepower transfer capabilityVSAvoidfuel consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent implements a continuously variable transmission system where the chain can be positioned at any point along the sprockets, enabling infinite gear ratio adjustments. This dynamic capability allows the transmission ratio to be continuously optimized for any vehicle speed and engine operating condition, maximizing power efficiency and minimizing fuel consumption.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The continuously variable transmission system provides universal adaptability across all operating conditions. Unlike fixed gear transmissions limited to specific ratios, this system can achieve any transmission ratio within its range, making it universally applicable to maintain optimal engine operation regardless of vehicle speed or load conditions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Power

If fixed gear ratios are used in conventional transmissions, then power transfer is achieved, but shock occurs when shifting between gear ratios, which can damage the transmission under high torque input power

Engineering Contradiction:

Improvepower transferVSAvoidtransmission durability

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The continuously variable transmission allows smooth, continuous adjustment of the chain position along the sprockets without discrete shifts. This eliminates the sudden torque shocks associated with fixed gear changes, protecting the transmission from damage under high torque conditions while maintaining full power transfer capability.

Inventive Principle:

Principle #15Dynamics

4Power

If unidirectional sprocket wheels are used with chain engagement, then power transmission is achieved, but the chain forms polygonal shape causing vibration and inefficiency

Engineering Contradiction:

Improvepower transmissionVSAvoidvibration from polygonal chain shape

Core Design Contradiction:

PowerVSObject-generated harmful factors

Solution Approach 1:

The patent employs frustoconical members with curved lateral surfaces that guide the chain in a smooth arc rather than allowing it to form a polygonal shape. This curvature ensures continuous contact between the chain and sprocket teeth, eliminating the vibration and inefficiency caused by polygonal chain formation while maintaining effective power transmission.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The frustoconical guide members act as intermediaries between the chain and the power transmission system. These guides maintain the chain in proper alignment and prevent polygonal formation by providing continuous curved support surfaces, thereby reducing vibration and improving transmission efficiency.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12234899B2Reduced vibration, shift compensating, continuously variable transmission

Publication Date: 2025.02.25 JOURDEN KEITH NICHOLAS

AI summary

An improvement to continuously variable transmissions whereby power is transmitted from a driver axle to a driven axle through a variable transmission mechanism. A plurality of unidirectional sprocket wheels positioned radially around a driver axle within a set of frustoconical members is provided so that the distance from the driver axle can be adjusted. The unidirectional sprocket wheels are connected by a chain to a similar driven axle portion. This low vibration, high torque capable transmission is superior to variable transmissions that rely on friction-based power transmissions that can slip during operation.