Micro Brushless Motor
Micro brushless motor is a type of electric motor that does not use brushes to deliver current to the rotor. It offers better performance and reliability than brushed motors.
In a brushed motor, the brushes and commutator generate friction that causes wear over time and reduces the lifespan of the motor. Brushless motors use different drive techniques to minimize torque ripple, a mechanical pulsation that generates vibration and noise.
Power
A Micro brushless motor might be small, but it is a powerhouse of torque. It plays a crucial role in enabling agility and functionality in portable devices, precision-oriented tech, and even manned drones.
Brushed motors use carbon brushes and a commutator to deliver current to the armature, causing it to rotate. As the brushes rub against each other, they generate considerable friction and wear that limits the lifespan of the motor. In addition, arcing between the brushes and the commutator generates electrical noise that can get coupled into sensitive circuitry.
In contrast, a brushless motor does not require carbon brushes or a commutator. Instead, a stationary stator contains multiple coils, or windings, that interact with permanent magnets on the rotor to generate a rotating magnetic field. The direction and speed of rotation can be controlled by varying the time and magnitude of current running through each coil.
The image above shows the inner workings of a typical DC brushless motor taken from an old 3.5 in floppy disk drive motor. The rotor, in this case a grey ring, encircles the stator’s winding. The electronic speed controller (ESC) on the right takes a throttle input signal from the control device and uses a frequency-based method to send a signal to the motor to tell it to accelerate or decelerate.
Efficiency
The micro brushless motor is able to operate more efficiently than brushed motors because they do not have brushes. This reduces friction and overall power loss. The motor can also be smaller in size, which is helpful for applications with limited space.
The commutator is part of the motor that connects the current source to the rotor. It reverses the direction of the current in the rotor every time it completes a half turn, which is how the motor can keep spinning without stopping. Brushless motors do not have a commutator, which eliminates the need for brushes and makes the motor smaller.
When testing the efficiency of a brushless motor, you will need a multimeter that can measure DC voltage and current. You will also need a drill or other device that you can use to spin the motor while taking your measurements. Then, you will need to take readings from the meter at zero RPM, max RPM and Micro brushless motor a few points in between to find the total power loss. This will allow you to subtract the power draw of the motor controller to eliminate their switching losses and measure the core loss of the motor.
Efficiency is measured as mechanical output power divided by electrical input power and can be calculated using the following formula. Copper loss is caused by the resistance of the copper windings to current flow and can be measured using the same formula. Iron loss is divided into eddy current and hysteresis losses, which result from the magnets in the rotor being magnetized and demagnetized as they rotate past the stator windings, causing energy to be lost as heat.
Weight
Micro motors are designed to be compact and lightweight, with low power consumption and minimal electromagnetic interference. These characteristics make them ideal for applications that require precise size and tight tolerances, as well as ruggedness to withstand harsh environments, extreme temperatures, vibration, impacts and electromagnetic interference.
A Micro brushless motor is an electrically commutated DC (BLDC) motor that has no brushes Rolling shutter door motor to generate friction and wear, which makes it more efficient than brushed motors. In a BLDC motor, semiconductor switches like transistors switch current between the stator windings and the rotor magnets to generate torque in one direction or the other. This eliminates the need for mechanical brushes and their commutator, which allows the motor to be smaller and more compact.
The most popular Micro brushless motors are used in battery-powered tools such as lawnmowers, leaf blowers, hedge trimmers and drills/drivers. They have greater efficiency and a longer lifespan than traditional corded tools that plug into an outlet.
A Micro brushless motor can also be found in powered surgical hand tools for performing minimally invasive medical procedures, such as joint repairs. These motors are optimized for high speed and torque, as well as for reliability in autoclave environments.
Reliability
The reliability of a micro brushless motor is influenced by several factors including its build quality, operating conditions and maintenance practices. Generally, they have a longer lifespan than brushed motors due to their more efficient design which reduces mechanical wear and tear.
The carbon brushes and commutator of traditional brushed motors rub against each other, creating friction and wear over time. These issues limit product longevity and can cause expensive maintenance, which is a major drawback for products that require continuous operation such as medical devices and consumer appliances.
In contrast, micro brushless motors have no carbon brushes and commutator, eliminating the friction and wear that limits their lifespan. Rather than rubbing against each other, the precious metal brushes of micro brushless motors connect to separate segments of a rotating commutator in order to reverse current flow, which causes the rotor shaft to rotate in the opposite direction.
Consequently, the lifespan of a micro brushless motor is often ten times longer than its brushed counterparts. In addition, the noise level of a brushless motor is often lower.
ASPINA offers a wide variety of small brushless DC motors with varying power, speed and torque ratings. This includes the 16BHS, which is designed to meet high standards for powered surgical hand tools used in minimally invasive surgery. This is made possible by its ability to withstand autoclave conditions, which is a key requirement for many medical applications.
