Torque Converter Capacity Coefficient Optimization for Electric Motor Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power transmission devices for vehicles face inefficiencies due to the torque converter's capacity coefficient increasing, causing the torque converter's characteristic line to intersect a low-efficiency region of the motor generator, preventing efficient utilization of the electric motor.
Innovation Solution
The power transmission device adjusts the torque converter's capacity coefficient so that its characteristic line intersects the electric motor's characteristic line in a range greater than the base rotational speed and less than the average rotational speed, allowing the torque converter to be reduced in size while efficiently utilizing the electric motor by passing through high-efficiency regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the capacity coefficient YJ of the torque converter is increased to cause the characteristic line TLJ to intersect the characteristic line ML for maximum output torque utilization, then the maximum output torque can be utilized, but the torque converter size (representative diameter φJ) increases and the motor generator operates in a low-efficiency region
Solution Approach 1:
The patent changes the capacity coefficient YJ of the torque converter from a conventional high value to a specifically designed lower value. This parameter change causes the characteristic line TL to intersect the maximum output torque characteristic line ML at a different operating point, allowing the torque converter to be smaller while keeping the motor generator operating in high-efficiency regions.
2Force
If the capacity coefficient YJ of the torque converter is increased to ensure torque transmission capability, then the torque converter can transmit sufficient torque, but the torque converter size increases and occupies more space
Solution Approach 1:
The patent optimizes the capacity coefficient YJ to a specific lower value that maintains sufficient torque transmission capability while reducing the representative diameter φJ of the torque converter. The redesigned characteristic line TL achieves the required torque transmission at a smaller size compared to conventional designs.
3Volume of moving object
If the torque converter size is reduced to decrease displacement, then the torque converter occupies less space, but the capacity coefficient YJ decreases and may insufficiently transmit torque
Solution Approach 1:
The patent determines a specific capacity coefficient YJ for the reduced-size torque converter that maintains adequate torque transmission. The characteristic line TL of the smaller torque converter is designed to intersect the maximum output torque characteristic line ML at an appropriate operating point, ensuring sufficient force transmission despite the smaller size.
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 configuration reduces the torque converter's size and enhances the efficient utilization of the electric motor by ensuring the torque converter's characteristic line passes through high-efficiency regions, improving overall power transmission efficiency.
Implementation Method 1
a torque converter (15). The torque converter is connected to the electric motor (13) and transmits torque of the electric motor (13) to an output member (5)
Data Source
AI summary
A power transmission device includes an electric motor, and a torque converter connected to the electric motor to transmit torque. A torque converter characteristic line is determined based on a capacity coefficient of the torque converter and indicates torque of the torque converter relative to each rotational speed of the torque converter. An electric motor characteristic line indicates a maximum output torque of the electric motor relative to each rotational speed of the electric motor. A first range corresponds to a range equal to and greater than a base rotational speed of the electric motor and equal to or less than a first average rotational speed, which is an average of the base rotational speed and a maximum rotational speed of the electric motor. The capacity coefficient is such that the characteristic line for the torque converter intersects the characteristic line for the electric motor in the first range.