Oil Pump Speed Control to Prevent Motor Cooling Oil Scatter
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Solution Overview
Problem
Oil pumps in electric vehicles face inefficiency in cooling the drive motor due to increased injection speed, leading to most injected oil not being used effectively, as it either bounces off or scatters from the motor coil, reducing cooling performance.
Innovation Solution
An oil pump system that adjusts its rotational speed based on the temperature gradient of the motor, using a controller to identify a target rotational speed and apply compensation values to optimize oil injection, ensuring efficient cooling by adjusting the rotational speed when it exceeds a limit speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the injection speed of oil is increased to cool the drive motor more effectively, then the cooling capacity is improved, but the oil scatters or bounces off the coil instead of flowing into it, reducing cooling performance
Solution Approach 1:
The oil pump's rotational speed is dynamically adjusted based on the drive motor's temperature and temperature gradient. The controller monitors temperature changes and modifies the oil pump speed in real-time, transitioning from a static high-speed operation to a dynamic adaptive speed control that optimizes oil injection under varying thermal conditions.
Solution Approach 2:
The system changes the operational parameters of the oil pump by adjusting its rotational speed according to the temperature gradient of the drive motor. When the temperature gradient exceeds a threshold, the controller reduces the pump speed to an adjusted value, thereby changing the oil injection characteristics to improve cooling effectiveness.
2Quantity of substance
If the rotational speed of the oil pump is increased to supply more oil for cooling, then the oil supply quantity is improved, but the cooling efficiency decreases due to oil scattering
Solution Approach 1:
The controller uses feedback from temperature detectors monitoring the drive motor's temperature and temperature gradient to adjust the oil pump's rotational speed. This closed-loop control ensures that the oil injection quantity is optimized based on actual cooling needs, preventing both insufficient and excessive oil injection that would scatter.
3Temperature
If the oil pump operates at high rotational speed to meet cooling demand, then the cooling capacity is improved, but the oil is wasted due to scattering and bouncing off the coil
Solution Approach 1:
Instead of continuously operating at maximum speed, the oil pump is controlled to operate at partially reduced speeds when the temperature gradient threshold is exceeded. This partial action approach supplies sufficient oil for cooling while avoiding the excessive injection that causes scattering and oil waste.
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 cooling efficiency of the drive motor by optimizing oil injection, preventing oil from scattering and ensuring effective heat management, thereby improving motor performance and extending its lifespan while reducing the load on the oil pump and improving vehicle stability and fuel efficiency.
Implementation Method 1
an oil pump configured to cool the drive motor by supplying oil to the drive motor
Data Source
AI summary
A method of controlling a vehicle includes steps of: detecting a temperature of oil; detecting a temperature of a drive motor; identifying a target rotational speed of an oil pump corresponding to the detected temperature of the oil and the temperature of the drive motor; when the identified target rotational speed is less than a limit rotational speed, controlling an operation of the oil pump based on the identified target rotational speed; and when the identified target rotational speed is greater than or equal to a limit rotational speed, adjusting the identified target rotational speed based on a temperature gradient of the drive motor in a current period and a temperature gradient of the drive motor in a previous period and controlling the operation of the oil pump based on the adjusted target rotational speed.