Unlike traditional brushed DC motors, BLDC motors are brushless and don’t require carbon brushes and copper commutator to operate. These motors are more efficient, quieter and offer superior longevity.
In new system designs, space constraints are driving the need for highly dynamic small-frame motors that can support torque density and speed requirements without requiring device redesign. ElectroCraft BLDC flat motors and associated planetary gear motors are ideally suited for these applications.
Size
BLDC motors are smaller than their brushed DC counterparts and offer more power in the same frame size. This makes them ideal for applications where space and weight are limited. They also consume less energy, making them more environmentally friendly than traditional motors.
Choosing a mini brushless motor for your application requires an understanding of the torque density and speed requirements you want to achieve. You can find several options to meet these specifications, including a range of frame sizes and configurations. You can even get a custom-designed solution to address your specific needs. For example, one of our customers was looking for high torque in a small footprint for their power seat application. We suggested an RPX series BLDC motor which was able to fit within their space constraints while still providing the desired performance.
Other options include an external rotor BLDC motor or an inner rotor BLDC motor. The former is designed with a fixed stator and rotating rotor, while the latter has the rotor inside the stator. Both types of motors are available in a variety of frame sizes and can be configured with various electronics.
Another option is a KinetiMax brushless BLDC motor from Allied Motion, which is designed for ventilators. This model can deliver up to 90,000 revolutions per minute and has a low mechanical time constant of 4ms. Its high torque density and small inertia make it a great choice for medical devices, pumps, fans, scanners and tools.
Power
Unlike stepper motors, which require pulses of current to hold the position of a structure, BLDC motors simply need current proportional to external force. That makes them more energy-efficient. They also have a smaller moment of inertia and are easy to control. That’s why service robots, which must keep the position of their arm even when they’re not moving, are increasingly using BLDC motors.
The PerformeX series of mini BLDC slotless motors from Allied Motion are built specifically to power powered surgical hand tools used in minimally invasive surgery for the knee, hip and miniature bldc motor shoulder. The design combines high speed and motor torque with low cogging and inertia, and it meets the sterilization requirements of autoclave applications.
These fractional horsepower motors are ideal for any application that requires high-speed positioning or speed control, including industrial and medical equipment, machine automation, and robotics. The multi-pole encapsulated core and high-performance rare earth neodymium magnets deliver exceptional torque per frame size performance.
For a high-speed motor that can match the input speeds of planetary gearboxes, look no further than the ElectroCraft LRPX40 BLDC motor. It features six self-supporting cylindrical ironless coils that allow it to run at high speeds without generating excess heat or noise. It delivers long life, excellent speed and position control and smooth rotation, making it perfect for respiratory and ventilation devices, clinical diagnostics, and miniature pumps and valves.
Efficiency
In many new system designs, torque density and speed requirements compete with size limitations. To meet these requirements, designers need a small motor with high efficiency and controllability. A miniature bldc motor is an excellent choice because it can deliver higher performance in a smaller frame.
This type of motor does not have brushes, which create friction that slows the motor down. The core of the rotor is magnetized and demagnetized by the current passing through stator windings. This causes eddy current and hysteresis losses that convert power to heat. These losses are reduced by using a lower motor frequency.
Additionally, the inverter that drives the motor also produces losses. miniature bldc motor wholesale These are not significant, but can be a problem in applications where the motor is exposed to the elements and needs to be sterilized after use.
To determine the efficiency of a BLDC motor, measure its no-load power draw and its power output at max RPM and zero RPM. Then, fit an efficiency curve to the data and subtract the zero RPM power draw to eliminate the motor controller switching losses. Subtracting this value will help you find the true core loss, which is the primary factor in determining motor efficiency. The resulting modelled efficiency map should closely match the measured one. This process can also be used to estimate copper and ventilation losses in AC induction motors.
Control
The performance of a miniature bldc motor can be enhanced with accessories like encoders and gearheads. These can add more torque, position, velocity or speed control, or they can improve dynamic response by lowering the inertia of the motor. It’s also important to consider the environmental factors of your application. Some BLDC motors are more efficient than others, and you’ll want to choose the one that suits your application best.
For example, if your application requires a tight control loop, consider using a sensored motor with encoder feedback. This can increase motor accuracy and reduce power wasted by adjusting the rotor speed to match the desired target. Alternatively, you could use an FPGA-based controller like TI’s Stellaris to achieve the same goal. It can control sensored or sensorless motors, has PID loops for power and RPM, an ethernet interface, and easy code building with free tools.
Lastly, you’ll want to think about the overall cost of your design. There are many different BLDC motor options available in a range of sizes and prices, so be sure to choose one that fits your budget. Additionally, look for a BLDC motor with a high efficiency rating to minimize energy losses and extend battery life. This will ensure that your design meets your performance requirements, while still maintaining a low cost.