Toroidal Variator Roller Orbiting for Variable Ratios
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Solution Overview
Problem
Existing infinitely variable ratio transmission apparatuses, such as variators, are costly and complex, making them unsuitable for less demanding environments due to the need for multiple rollers and hydraulic control systems, which are necessary for stability and torque handling in high-power applications.
Innovation Solution
A toroidal variator design with pivotal mountings and rollers that orbit around a rotational axis, allowing for variable transmission ratios by adjusting the contact loci diameters and angles between rollers and drive surfaces, enabling an infinite range of positive and negative ratios, including 'geared neutral', and potentially biased ratios, using a mechanism with a control ring and planet gears to adjust the inclination of rollers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple rollers and hydraulic control systems are used to handle high power and torque, then power handling capability is improved, but device complexity and cost increase
Solution Approach 1:
The patent merges the functions of multiple rollers into a single roller that simultaneously engages with both toroidal discs, eliminating the need for separate hydraulic control systems for each roller. This single roller is pivotally mounted to allow it to automatically adjust its position and maintain frictional engagement with both discs, thereby reducing device complexity while maintaining power handling capability.
Solution Approach 2:
The single roller is equipped with a pivotal mounting that allows it to self-adjust its position and orientation in response to varying torque and power conditions. The roller automatically maintains optimal engagement with the toroidal discs through its pivotal motion, eliminating the need for complex hydraulic control systems and computer control, thereby reducing device complexity while preserving power handling capability.
2Stability of the object's composition
If three rollers are used in each toroidal cavity for stability, then transmission stability is improved, but device complexity and cost increase
Solution Approach 1:
The patent combines the stabilizing function of three rollers into a single roller with pivotal mounting capability. This single roller maintains stability by automatically adjusting its pivotal position to optimize engagement with the toroidal discs, thereby achieving transmission stability without the complexity of three separate rollers and their associated hydraulic control systems.
Solution Approach 2:
The roller is designed with dynamic pivotal mounting that allows it to adapt its position and orientation in real-time according to operating conditions. This dynamic adjustment capability enables the single roller to maintain stable transmission performance across varying torque and power levels, replacing the static three-roller arrangement with a more complex system.
3Manufacturing precision
If each roller is provided with its own double-acting control piston, then roller control precision is improved, but device complexity and cost increase
Solution Approach 1:
The roller's pivotal mounting enables it to self-regulate its position and engagement force with the toroidal discs in response to varying operating conditions. This self-adjusting mechanism eliminates the need for double-acting control pistons and computer-controlled hydraulic systems, thereby maintaining roller control precision while dramatically reducing device complexity and cost.
Solution Approach 2:
The pivotal mounting acts as an intermediary mechanism that translates varying torque and power conditions into appropriate roller position and engagement force adjustments. This passive mechanical intermediary replaces the need for active hydraulic control systems, maintaining control precision without the associated complexity and cost.
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 design provides a cost-effective and versatile transmission system capable of infinite positive and negative ratios, including reverse gearing and 'geared neutral', suitable for various applications by simplifying the mechanical complexity and reducing the need for multiple rollers and hydraulic control, while maintaining durability and stability.
Implementation Method 1
power is transmitted from the input disc to the output disc by means of the rollers... ensure that the rollers are frictionally engaged with the input and output discs
Implementation Method 2
the transmission output is driven by orbiting of the pivotal mountings around the rotational axis of the variator
Data Source
AI summary
A transmission comprises a toroidal variator having first and second spaced-apart drive discs (12, 14) defining a toroidal cavity about a rotational axis (x-x), a transmission input (22) arranged to drive the first and second drive discs (12, 14) in opposite directions and supported on pivotal mountings between the drive discs (12, 14), one or more rollers (18, 20) arranged to contact the said drive discs (12, 14) and be driven thereby, wherein the transmission output (44) is driven by orbiting of the pivotal mountings around the rotational axis of the variator.