Infinitely Variable Transmission Worm Gear Helix Optimization
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Solution Overview
Problem
Infinitely variable transmissions in automotive vehicles face challenges in minimizing power required to drive worm gears while maintaining efficient torque delivery and optimizing engine efficiency across varying load conditions.
Innovation Solution
The selection of a specific worm gear helix angle balances worm gear teeth friction and load, and an electronic control unit determines whether to operate the internal combustion engine at an optimum efficiency set point, modifying the angular velocity of the electrical motor to satisfy torque demands while minimizing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the worm gear helix angle is increased to reduce friction, then power required to drive the worm gear decreases, but the load capacity of the worm gear is reduced
Solution Approach 1:
The patent applies parameter changes by optimizing the worm gear helix angle to a specific range (30-45 degrees) to achieve the best balance between reducing friction/power consumption and maintaining sufficient load capacity. This parameter optimization resolves the contradiction by finding the optimal value that satisfies both requirements simultaneously.
2Power
If the electrical motor speed is increased to satisfy torque demand, then torque delivery is improved, but power consumption increases
Solution Approach 1:
The control system continuously monitors torque demand and electrical motor speed, and dynamically adjusts the motor speed to satisfy torque requirements while minimizing power consumption. The feedback mechanism ensures the motor operates at optimal speed for given load conditions, resolving the contradiction between torque delivery and power consumption.
Solution Approach 2:
The system dynamically adjusts electrical motor speed based on real-time torque demand rather than operating at fixed speed. This dynamic control allows the system to deliver required torque while minimizing power consumption by avoiding excessive motor speeds.
3Power
If the internal combustion engine operates away from optimal efficiency set point to satisfy torque demand, then torque delivery is improved, but fuel economy deteriorates
Solution Approach 1:
The electrical motor acts as an intermediary that assists the internal combustion engine in meeting torque demands. By providing supplemental torque from the electrical motor, the system allows the ICE to operate closer to its optimal efficiency set point while still satisfying overall torque requirements, thus resolving the contradiction between torque delivery and fuel economy.
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 approach reduces the power required by the electrical motor, enhances engine efficiency, and allows for seamless torque delivery across a range of load conditions, improving fuel economy and vehicle performance.
Implementation Method 1
selection of the worm gear helix angle to effect a balance between worm gear teeth friction and load placed on the worm gear
Data Source
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AI summary
An exemplary infinitely variable transmission includes a planetary gear set situated in a drive train of an automotive vehicle and interfaced with a worm gear driven by an electrical motor continuously controlled by an electronic control unit in response to a torque demand. Another aspect may be selection of the worm gear helix angle to effect a balance between worm gear teeth friction and load placed on the worm gear by the planetary gear set, such that power required to drive the worm gear is minimized for all input load conditions.