Carbon Composite Rotor Structure for Motor Cooling and Weight Reduction
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Solution Overview
Problem
Current electric motors with metal rotors are heavy, require additional cooling for higher capacities, and struggle with efficient temperature management.
Innovation Solution
A carbon composite rotor is formed by densifying and carbonizing a laminated structure of open carbon fiber fabric or needled preform, with resin infiltration and chemical vapor infiltration, and incorporating a central bore and magnet apertures for improved cooling and weight reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If metal rotors are used in electric motors, then structural strength is ensured, but weight increases and cooling efficiency deteriorates
Solution Approach 1:
The patent applies composite materials by using carbon fiber reinforced polymer (CFRP) composite structure for the rotor. The carbon fiber provides high strength and stiffness while the polymer matrix provides thermal management capabilities. This composite approach enables simultaneous weight reduction and improved cooling efficiency, as the polymer matrix can be designed with high thermal conductivity in specific directions to conduct heat away from critical areas.
Solution Approach 2:
The patent changes the material parameters by transitioning from traditional metal (aluminum or steel) to carbon fiber composite materials. This parameter change involves modifying the thermal conductivity, density, and mechanical strength properties. The carbon fiber composite allows for tailored thermal pathways while maintaining structural integrity, enabling the rotor to operate at higher temperatures with better heat dissipation.
2Power
If metal rotors are used in electric motors, then mechanical strength is maintained, but power-to-weight ratio deteriorates
Solution Approach 1:
The carbon fiber reinforced polymer composite material provides exceptional strength-to-weight ratio. The carbon fiber reinforcement provides high tensile strength and stiffness, while the polymer matrix binds the fibers and provides structural continuity. This composite structure achieves higher mechanical strength at lower weight compared to traditional metal rotors, thereby improving the power-to-weight ratio of the electric motor.
Solution Approach 2:
The rotor structure is segmented into distinct functional zones using the composite material layers. The carbon fiber fabric is arranged in specific orientations (e.g., 0°, 90°, ±45° layers) to provide strength in different directions where needed. This segmentation allows optimization of mechanical properties in critical areas while reducing weight in non-critical areas, maximizing the overall power-to-weight ratio.
3Temperature
If additional cooling mechanisms are added to metal rotors, then temperature management improves, but device complexity increases
Solution Approach 1:
The polymer matrix in the carbon fiber composite rotor serves multiple functions: it binds the carbon fiber reinforcement, provides structural support, and acts as a thermal management system. The composite material itself is designed with anisotropic thermal conductivity, creating built-in heat pathways that conduct heat away from the rotor windings and permanent magnets. This multi-functionality eliminates the need for separate cooling mechanisms, reducing device complexity while maintaining effective temperature management.
Solution Approach 2:
The carbon fiber composite rotor structure provides its own cooling capability through the inherent thermal conductivity of the polymer matrix. The material is designed to conduct heat away from critical areas internally, without requiring external cooling systems. The rotor body itself serves the cooling function, eliminating the need for additional coolers or complex thermal management systems.
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 carbon composite rotor enhances cooling efficiency, reduces weight, and eliminates the need for additional cooling mechanisms, achieving a higher power-to-weight ratio and improved thermal management.
Implementation Method 1
providing a resin infiltration between each layer of the laminated structure
Implementation Method 2
heating (e.g., heat treating) the laminated structure, such that densifying includes, densifying the laminated structure
Implementation Method 3
carbonizing the disk, to form a carbon-carbon rotor
Implementation Method 4
densifying can include densifying the open fiber needled preform by chemical vapor infiltration (CVI)
Data Source
AI summary
In accordance with at least one aspect of this disclosure, a method of making a carbon rotor includes, providing a quantity of material, densifying the quantity of material, and forming the densified material into a disk shape.