EV Transmission Lubricant Heating for Cold-Start Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric vehicles exhibit reduced efficiency at cold temperatures, particularly when first operated.
Innovation Solution
A control system that adjusts the flow of lubricant fluid through a heat exchanger and bypass paths to heat the transmission, utilizing thermal energy from the traction electric machine or other sources to maintain the transmission temperature above a threshold, thereby improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the vehicle operates in cold temperatures, then the vehicle can be used, but the transmission efficiency decreases due to low lubricant temperature
Solution Approach 1:
The system performs preliminary heating of the transmission by diverting coolant flow through the transmission before normal operation begins. The coolant pump directs flow through bypass paths that route coolant through the transmission housing and lubricant, raising the temperature to optimal operating range before the vehicle is driven, thereby preventing power loss during cold-temperature operation
Solution Approach 2:
The coolant acts as an intermediary heat transfer medium between the electric machine (which generates heat during operation) and the transmission lubricant. By controlling coolant flow paths through valves and bypass routes, thermal energy is transferred from the coolant to the transmission, indirectly heating the lubricant without direct contact between the heat source and lubricant
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
Enhances transmission efficiency by maintaining optimal operating temperatures, reducing power loss, and improving overall vehicle performance.
Implementation Method 1
a heat exchanger for exchanging thermal energy between a coolant fluid and a lubricant fluid
Implementation Method 2
utilizing thermal energy from the traction electric machine
Data Source
Figure 1a~1b
Figure 2
Figure 3
AI summary
Aspects of the present invention relate to a control system, comprising one or more controllers, for an electric vehicle, the control system comprising input means (130) to receive a temperature signal (135) indicative of a temperature of a transmission (160) associated with a traction electric machine (150) of the vehicle, output means (140) to output a flow control signal (145) for controlling a flow control means to control a flow of lubricant fluid associated with the traction electric machine and the transmission through a heat exchanger, and processing means (110) arranged to control the output means to output the flow control signal in dependence on the temperature signal.