Exploring the main differences between an axial flux motor and a radial flux motor.
The world is rapidly electrifying, and as a result, millions of things we use in business and life are electrifying, too. And all those devices need electric motors to operate. As electric motors become more specialized and ubiquitous, more engineers and designers are studying their topology. Quite frequently, that exploration quickly leads to this question: what’s the difference between axial flux vs. radial flux machines?
That’s no surprise since axial flux motors and radial flux motors are two types of common electric motors. Both convert electrical energy into mechanical energy, but they differ substantially in design and assembly. Radial flux motors have been around longer are more frequent. However, in the past few decades, axial flux motors have become more prevalent due to their significant advantages over radial flux machines for many applications.
What’s the difference between axial flux vs. radial flux machines?
The main difference between axial and radial motors has to do with their magnetic fields.
In axial flux motors, the magnetic field is parallel to the shaft and the windings are arranged in a planar fashion. This design allows for a more compact motor, with shorter axial length and a disc, rather than cylindrical form factor. In a radial flux motor, the magnetic field is perpendicular to the shaft and the windings are arranged in a cylindrical fashion. This design is typically larger and bulkier.
In addition to being a more compact motor, Axial flux motors offer many other substantial advantages over radial flux machines.
Some of the key benefits provided include:
- Lightweight construction
- High power density
- Increased durability
- High torque-to-weight ratio
- Increased energy efficiency
- Reduced raw material use; and
- Flexibility in design
There are many electric motor applications that can benefit from an axial flux topology.
Some common household applications of note include heating and cooling systems (such as pumps and fans), kitchen devices (such as blenders and coffee machines), power and yard tools (such as drills and lawnmowers), home appliances (such as washing machines and dishwashers), and other typical household items that aren’t as obvious (such as exercise bikes and baby rockers). The most direct benefits to these household applications from axial flux motors include the following:
- Longer battery life and cheaper electricity bills (derived from higher efficiencies)
- Greater product reliability and longer product life cycles; and
- A slim form factor—which allows for sleeker and more affordable products that are less costly to design, produce, and distribute
There are also many new innovations that can benefit from axial flux motors including electric vehicles—due to the compact size and high-power density and efficiency—wind turbines—due to the low profile and high torque-to-weight ratio—medical bionics and advanced cinematography—due to the quality of motion and controllability—and industrial automation such as robotics and conveyors—due to durability, reliability, and flexible form factor.
Leveraging the many benefits offered by axial flux topology, ECM’s new PCB stator axial-flux electric motor improves on older designs by utilizing advanced printed circuit board technology.
ECM’s PCB stator solution replaces the copper-wound iron core, that is generally found in an electric motor, with a multi-layered PCB—optimizing copper geometry to offer the same power with 20% of the material and unlocking unmatched design flexibilities. PCB stator motors offer all of the technical benefits associated with axial flux motors while significantly reducing the mass and size of the stator incorporated in electric motors.
PCB stator motors using axial flux topology offer many benefits beyond non PCB axial flux motors:
- Reduced acoustic noise
- Reduced electromagnetic interference
- Increased energy efficiency
- Minimal axial thinness
- Increased energy efficiency
- Effective thermal dissipation; and
- Decreased manufacturing costs
ECM’s PCB stator solutions are designed and optimized using ECM’s proprietary PrintStator Motor CAD software.
PrintStator uses advanced algorithms and optimization criteria to design and manufacture exact PCB stator axial flux motors for each use case and application. Since PCB stators are constructed using the methods of a PCB and do not involve copper windings, PCB stator motors also offer unrivaled design flexibility and can be designed for many shapes and forms.
The world is shifting toward axial flux motor topology for its many advantages over traditional radial flux motor topology, including a compact form factor, increased reliability, and increased energy efficiency.
ECM’s PCB stator motor platform takes axial flux topology one step into the future—offering a simple design and manufacturing process for axial motors that have many benefits above and beyond the traditional axial flux electric motor.
