Hybrid Motor and Controller Cooling With Oil-Water Heat Exchange

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Solution Overview

Problem

Existing new energy vehicle drive motors require a more effective cooling system to manage increased power density, as current independent water and oil cooling systems are insufficient for continuous high power and high torque output.

Innovation Solution

A combined cooling system integrating a water cooling assembly, an oil cooling assembly, and an oil-water heat exchanger, where the water cooling assembly includes a radiator, fan, and water pumps, and the oil cooling assembly includes an oil pump and pipe, with intelligent control of pumps and fans to optimize cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If independent water cooling system is used, then cooling coverage is comprehensive, but cooling efficiency is insufficient for high power density motors

Engineering Contradiction:
Improvecooling coverageVSAvoidcooling efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent combines water cooling and oil cooling systems into a hybrid cooling system. The water cooling assembly handles general cooling needs while the oil cooling assembly provides intensive cooling for high-temperature areas, achieving both comprehensive coverage and high cooling efficiency required for high power density motors.

Inventive Principle:
Principle #5Merging (Combining)

2Productivity

If independent oil cooling system is used, then cooling efficiency is high, but cooling coverage is limited

Engineering Contradiction:
Improvecooling efficiencyVSAvoidcooling coverage
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent integrates oil cooling and water cooling systems where the oil cooling assembly targets specific high-temperature zones with high efficiency, while the water cooling assembly provides broader coverage. The oil-water heat exchanger couples these systems to achieve both high cooling efficiency and comprehensive coverage.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If separate water and oil cooling systems are used, then cooling performance is adequate, but system complexity increases

Engineering Contradiction:
Improvecooling performanceVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges separate water and oil cooling systems into an integrated hybrid cooling system with a unified control strategy. The controller coordinates water pumps, oil pumps, and heat exchangers as a single system, maintaining adequate cooling performance while reducing overall system complexity through integration.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hybrid cooling system serves multiple functions: the water cooling assembly handles general cooling, the oil cooling assembly targets high-temperature zones, and the oil-water heat exchanger couples the two systems. This multi-functional integration allows a single system to address various cooling requirements without requiring entirely separate systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Power

If power density of motor is increased, then motor performance is improved, but cooling requirement increases

Engineering Contradiction:
Improvemotor performanceVSAvoidcooling requirement
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The patent employs a hybrid cooling system that combines water cooling and oil cooling capabilities to meet the increased cooling requirements of high power density motors. The system dynamically adjusts cooling capacity to match the thermal load generated by high-performance motor operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cooling system incorporates dynamic control through controllers that adjust pump speeds, flow rates, and heat exchanger operations based on real-time temperature and load conditions. This dynamic adaptation allows the system to meet varying cooling requirements as motor power density and thermal load change during operation.

Inventive Principle:
Principle #15Dynamics

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

The combined cooling system enhances cooling efficiency, reduces energy consumption, and improves environmental adaptability by leveraging the lower operating temperature of the motor controller, achieving better balance between energy saving and cooling performance.

Implementation Method 1

an oil-water heat exchanger; one end of the water cooling assembly is connected to a cooling water outlet of the motor, the other end of the water cooling assembly is only connected to a cooling water inlet of the motor controller, a cooling water outlet of the motor controller is connected to a water inlet of an oil-water heat exchanger

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a radiator, a fan, a first water pump, and a water pipe, the radiator is connected in series with the first water pump, and the fan is used for cooling the radiator

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 3

The water cooling of motor uses heat conduction. The heat generated by the motor windings and bearings is first transferred to the motor housing provided with cooling water pipes therein

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3984798B1Combined cooling system of an electric motor and a motor controller
Publication Date: 2023.11.29 JING JIN ELECTRIC TECH CO LTD
  • EP3984798B1 patent drawingFigure 1~2
  • EP3984798B1 patent drawingFigure 3~4
  • EP3984798B1 patent drawingFigure 5

AI summary

The present disclosure discloses a combined cooling system for a motor and a motor controller, which comprises a water cooling assembly, an oil cooling assembly, and an oil-water heat exchanger; one end of the water cooling assembly is connected to an cooling water outlet of the motor, the other end is connected to an cooling water inlet of the motor controller and/or a water inlet of the oil-water heat exchanger; one end of the oil cooling assembly is connected to a cooling oil outlet of the motor, the other end of the oil cooling assembly is connected to an oil inlet of the oil-water heat exchanger, and an oil outlet of the oil-water heat exchanger is connected to a cooling oil inlet of the motor. The above technical solution utilizes the temperature characteristics of the motor and the motor controller, and achieves the objects of saving energy in cooling, and improving high power output performance and environmental adaptability of the motor through the cooperation and intelligent control of the water pump, oil pump and fan in the combined cooling system.