Fiber Composite Can for Electric Machine Rotor Protection
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Solution Overview
Problem
Conventional electrical machines face efficiency losses due to friction from cooling fluids and parasitic electric currents caused by ferromagnetic materials in the effective area, which can weaken the electromagnetic field and lead to buckling failures in containment cans.
Innovation Solution
A split tube can made of fiber composite material with a winding angle of 88°, embedded in a stator laminated core, prevents cooling fluid penetration and maintains a ferromagnetic-free effective area, enhancing efficiency and stability while preventing buckling through a sealing layer and axial alignment with the machine housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal can is used to separate the rotor from the cooling fluid, then the rotor is protected from friction and braking effects, but parasitic electric currents are generated due to ferromagnetic materials in the effective area
Solution Approach 1:
The ferromagnetic material is extracted from the can structure by using a non-ferromagnetic plastic base material, eliminating the source of parasitic electric currents while maintaining the can's protective function
Solution Approach 2:
A composite material structure is employed where glass fibers (non-ferromagnetic) are embedded in a plastic matrix, creating a can that provides mechanical strength without ferromagnetic properties that cause energy losses
2Strength
If the can wall thickness is increased to prevent buckling under pressure loads, then structural stability is improved, but the effective area is reduced and efficiency decreases
Solution Approach 1:
The composite material structure with glass fibers provides high strength-to-weight ratio, enabling thin-walled construction (0.5-2mm) that resists buckling while minimizing intrusion into the effective area
Solution Approach 2:
The winding angle parameter is optimized to 88° to maximize the mechanical strength of the fiber reinforcement, allowing the can to withstand pressure loads with minimal wall thickness
3Device complexity
If a fiber composite can with winding angle of 10° to 40° is used, then the can structure is simplified, but the can lacks sufficient stability and may buckle under pressure loads
Solution Approach 1:
The winding angle parameter is changed from conventional values (10°-40°) to an optimized value of 88°, which maximizes the circumferential strength and radial stability of the can under pressure loads
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 solution significantly reduces churning losses, maintains high efficiency, and prevents buckling failures, ensuring reliable operation under pressure loads while maintaining a strong electromagnetic field.
Implementation Method 1
a can (26) made of a fiber composite material (60), wherein the fiber (62) has a winding angle (66) with respect to a longitudinal direction (28) of the can (26), wherein the winding angle (66) is 88°
Implementation Method 2
The stator (46) is cooled by means of a cooling fluid (42) in order to dissipate the heat that occurs as a result of the power loss caused by operation
Implementation Method 3
the winding package (50) is set up to interact electrodynamically with the rotor (20)
Data Source
Figure 1
Figure 2
AI summary
The invention relates to an electric machine (2), in particular an electric motor, comprising a one-piece can (26) which is disposed between a stator (46) and a rotor (20), wherein the tubular casing (58) of said can, which is loaded with external pressure by a coolant (42) in a machine housing (10), is made of a fibre composite material (60). The casing thickness (68) of the can (26) is less than 2.5mm and greater than 0.5mm.