Toroidal CVT Oscillating Roller Torque Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hybrid traction systems for vehicles face inefficiencies due to the use of toroidal continuously variable transmissions (CVTs) that experience torque reduction with increased speed, requiring auxiliary systems that are costly and unreliable, and energy dissipation during braking and deceleration, leading to reduced overall efficiency and increased costs.
Innovation Solution
A continuous speed variation device with a toroidal CVT that uses two coaxially arranged toroidal friction discs with oscillating spherical roller members to vary transmission ratios without clamping force adjustments, allowing for efficient power transmission and reversal, eliminating the need for discrete gearboxes, brakes, and energy-dissipating mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a toroidal CVT with oscillating roller is used to enable continuous speed variation, then the transmission ratio can be varied continuously, but the torque transmission capability progressively decreases with increased speed
Solution Approach 1:
The patent applies dynamics by making the roller's direction of charge oscillate independently from its rotation, allowing the contact location to vary dynamically. This enables continuous speed variation while maintaining torque transmission capability through dynamic adjustment of the charge direction rather than relying on fixed geometric relationships that degrade at high speeds
2Power
If auxiliary systems are added to compensate for torque reduction in toroidal CVT, then the torque transmission capability is improved, but the device complexity and cost increase
Solution Approach 1:
The patent applies self-service by enabling the toroidal CVT to maintain its torque transmission capability through its own inherent dynamic characteristics. The oscillating roller mechanism with independent charge direction control allows the system to self-regulate and maintain performance without requiring external auxiliary systems such as hydraulic pumps, proportional valves, or complex control software
3Duration of action of stationary object
If a brake system is added to prevent neutral running of the internal combustion engine, then the engine operates continuously, but energy is dissipated during braking operations
Solution Approach 1:
The patent converts the harmful energy dissipation during braking into a beneficial regenerative process. The toroidal CVT's ability to operate in reverse and its continuous variability allow the electric motor to function as a generator during deceleration, converting the vehicle's kinetic energy back into electrical energy to recharge the battery, thus eliminating energy waste while maintaining engine operation
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 solution enhances the overall efficiency of hybrid vehicles by maintaining optimal torque and power transmission across varying speeds, reducing energy loss, and eliminating the need for costly auxiliary systems, resulting in improved reliability and cost savings.
Implementation Method 1
a first toroidal friction disc (266) which is mechanically connected to the shaft (81) and, accordingly, will be also indicated in the following as input toroidal friction disc, and a second toroidal friction disc (270) which is connected to the first toroidal friction disc (266) by means of at least two roller members (268)
Data Source
AI summary
A continuous speed variation device includes a input friction disc, a output friction disc, and at least three idle oscillating friction roller members. The input and output friction discs have a friction surface of toroidal shape and the idle oscillating roller members have a friction surface shaped in the form of a spherical dome.