Rotor Spray-Hole Cooling for Oil-Cooled Motor Coils
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric motor cooling methods, particularly direct cooling with oil, suffer from reduced rotational force and efficiency due to resistance from oil immersion, leading to noise and inefficiencies.
Innovation Solution
A motor design featuring end plates with ribs and spray holes that guide and pump oil using centrifugal force to enhance convection cooling while minimizing resistance, incorporating a cooling fluid accommodating portion and spray holes to direct oil onto the coil surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If spatulas are integrally attached on the rotor to scoop up oil for cooling, then cooling performance is improved, but rotational force is reduced and motor efficiency is lowered
Solution Approach 1:
The patent extracts the harmful interaction between the rotor and oil by removing the traditional spatula structure that scooped oil. Instead, it introduces a rotor with an inclined surface that passively guides oil flow without active scooping, eliminating the resistance and efficiency loss while maintaining cooling functionality through the inclined surface geometry.
Solution Approach 2:
The patent inverts the traditional cooling approach by not actively scooping oil with protruding spatulas, but rather using an inclined surface to passively guide oil flow. This inversion transforms the harmful resistance into a beneficial flow guidance mechanism, improving both cooling efficiency and motor performance.
2Temperature
If oil is used for direct cooling of the motor, then cooling efficiency is improved, but resistance from oil immersion reduces motor efficiency
Solution Approach 1:
The patent applies local quality by creating a specific inclined surface structure on the rotor that optimizes oil flow in the critical cooling zone. The inclined surface is positioned and angled to guide oil precisely where cooling is needed, ensuring effective heat removal while minimizing overall oil resistance and energy loss.
Solution Approach 2:
The patent changes the geometric parameters of the rotor surface by introducing an inclined surface with specific angle and dimensions. This parameter change transforms the oil-rotor interaction from a resistance-generating contact to a flow-guiding surface, optimizing both cooling efficiency and motor efficiency simultaneously.
3Temperature
If conventional cooling methods are used, then motor cooling is achieved, but convection cooling of oil is insufficient
Solution Approach 1:
The patent introduces dynamics by utilizing the rotational motion of the rotor itself to drive oil convection. The inclined surface on the rotating rotor actively propels oil from the lower to upper portions of the motor housing, creating dynamic convection currents that significantly accelerate cooling compared to static conventional methods.
Solution Approach 2:
The patent implements self-service by using the rotor's own rotation to generate the convection flow needed for cooling. The rotating inclined surface automatically pumps oil without requiring external pumps or complex mechanisms, enabling the system to cool itself through its inherent operational motion.
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 design effectively accelerates oil convection cooling, reducing resistance and maintaining motor efficiency by guiding and spraying oil onto the coil surface, thus enhancing cooling performance.
Implementation Method 1
pump the accommodated oil into an upper portion of the motor housing as rotating in response to rotation of a rotor, such that the oil can be sprayed onto a coil from an upper portion of the end plate through the spray holes by a centrifugal force
Implementation Method 2
spray oil, which is introduced into the spray holes or a cooling fluid accommodating portion during rotation of a rotor, onto an inner surface of the coil by a centrifugal force, thereby cooling the inner surface of the coil
Implementation Method 3
accelerating convection cooling of oil
Implementation Method 4
cool down heat generated in the electric motor
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a motor comprising: a motor housing; a stator which is provided in the motor housing and has a coil; a rotor installed in the stator to be rotatable about a rotary shaft; and a spray hole which is formed in the circumferential surface of the rotor by passing through the circumferential surface in a radial direction and which sprays a cooling fluid in the motor housing onto the coil according to the rotation of the rotor. Therefore, cooling by oil convection can be accelerated while minimizing resistance due to the oil.