Vehicle Motor Cooling Circuit with Inlet Pipe Positioning
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Solution Overview
Problem
In hybrid vehicles with two-system cooling circuits, the low viscosity of refrigerant in the motor's secondary cooling circuit leads to decreased flow velocity, making it difficult to discharge trapped air during manufacturing, which affects productivity and cooling efficiency.
Innovation Solution
A cooling structure with a first cooling circuit for the engine and a second cooling circuit for the motor and electric device, where the second circuit includes a circumferential flow path with an inlet pipe positioned on the first motor internal flow path side, allowing heat exchange to increase refrigerant temperature and viscosity, facilitating the discharge of air stagnation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a second cooling circuit with lower temperature is used to cool the motor, then the cooling efficiency of the motor is improved, but the viscosity of the refrigerant increases and flow velocity decreases, making it difficult to discharge trapped air
Solution Approach 1:
The cooling circuit is divided into two separate systems: a first cooling circuit for the engine and a second cooling circuit for the motor. This segmentation allows each circuit to operate at optimal temperatures independently, with the second circuit maintaining lower temperatures for motor cooling while the first circuit handles higher temperatures for engine cooling.
Solution Approach 2:
The inlet pipe is positioned on the first motor internal flow path side to perform preliminary heating of the refrigerant before it enters the circumferential flow path. This preliminary action increases refrigerant temperature and reduces viscosity in advance, ensuring adequate flow velocity for air discharge throughout the cooling circuit.
2Speed
If the inlet pipe is positioned on the first motor internal flow path side, then heat exchange increases refrigerant temperature and flow velocity, but the refrigerant temperature available for motor cooling may be reduced
Solution Approach 1:
Different sections of the cooling circuit are assigned different temperature requirements. The inlet pipe section benefits from higher temperature for flow velocity, while the motor cooling section operates at lower temperatures for effective heat removal. This local quality differentiation resolves the temperature-velocity trade-off.
Solution Approach 2:
The cooling circuit is segmented into distinct functional zones: a heating zone where the refrigerant gains temperature for flow velocity, and a cooling zone where the refrigerant removes heat from the motor. This segmentation allows each zone to optimize for its specific function without compromising the other.
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 enhances the flow velocity of refrigerant in the second cooling circuit, effectively discharging air stagnation without impacting the motor's cooling efficiency, thus improving manufacturing productivity and maintaining cooling efficiency.
Implementation Method 1
an inlet pipe (for example, an inlet pipe 34 in the embodiment) configured to allow the refrigerant to flow into the circumferential flow path... heat exchange to increase refrigerant temperature and viscosity
Implementation Method 2
a circumferential flow path (for example, a circumferential flow path 33 in the embodiment) configured to allow a refrigerant (for example, a refrigerant S in the embodiment) to flow along a circumferential direction of the motor
Data Source
AI summary
Provided is a cooling structure of a vehicle, which suppresses air stagnation in the motor when manufacturing, and improves productivity, while maintaining cooling efficiency of a motor. A cooling structure of a vehicle is equipped with a first cooling circuit (41) configured to cool an engine; and a second cooling circuit (42) configured to cool a motor (3) and an electric device including an inverter which connects the motor (3) and a power storage device, in which the first cooling circuit (41) has a first motor internal flow path (20) provided in a motor case (12), the second cooling circuit (42) has a second motor internal flow path (30) provided in the motor case (12), the second motor internal flow path (30) has a circumferential flow path (33) configured to allow a refrigerant (S) to flow along a circumferential direction of the motor (3), an inlet pipe (34) configured to allow the refrigerant (S) to flow into the circumferential flow path (33), and an outlet pipe (35) configured to discharge the refrigerant (S) from the circumferential flow path (33), and the inlet pipe (34) is disposed to be closer to the first motor internal flow path (20) side than the outlet pipe (35).