Although brushless motor technology emerged half a century ago in the industry, in recent years it has made a great revolution in the manufacture of new tools, particularly cordless ones. Machines equipped with Brushless motors normally provide high work performance, since, unlike models with brushes, their motor adjusts according to the task for which it is intended.
What is the brushless motor and what is its origin?
The brushless motor is a normal electric motor, it just does not use brushes to fulfill the change of polarity in the rotor. The aforementioned motor, also known as a Brushless motor or BL motor, takes advantage of a thin collector or a pair of slip rings to turn the rotary axis. In fact, they replace the brushes with an electronic controller, called an ESC, to do the commutation.
The origin of this type of motor goes back to the year 1886, when the American Frank Julian Sprague invented the first direct current (DC) motor, a sparkless device that maintained a relatively constant speed under variable loads. Over the years, these motors became more widely used by many operators due to their economical price, lightweight and easy maintenance.
What are the advantages of brushless motors?
I. More energy efficiency
Brushless dc motor has no friction and no voltage drop, important factors that increase motor life and offer better overall performance. Likewise, it causes battery life and run time, and greatly reduces tool maintenance.
II. more responsive
Power tools that have brushless motors are capable of adjusting their speed, torque, and power supply depending on the application and job they are intended for. For example, when we use a brushless drill to drill through a lightweight material like drywall or a dense material like mahogany, we can tailor just enough power to get the job done, while brushless drills provide the same amount of power regardless of the strength of the material they are drilling.
III. longest shelf life
Brushes wear out over time due to friction. So, the lifespan of brushed motors lasts almost 2000 hours, while brushless motors normally work more than 10000 hours. It should be remembered that these numbers are only shown as general rules, as there are a large number of factors that can affect the typical life of an electric motor.
IV. Highest number of RPM
Appliances with brushless motors pack more power and torque. They can also offer incredible no-load speed. In some single-pole brushless motors, the no-load speed can reach about 100,000 revolutions per minute (RPM).
V. Easy maintenance
A normal motor requires new brushes after every 50 to 60 hours of use, but Brushless models do not have brushes that need to be replaced.
What is a Gear motor?
A gearmotor is a single component that integrates a gear reducer with an AC or DC electric motor. Thanks to its set of gears, a geared motor can deliver high torque at low power or low speed.
Dc gear motor is more common in applications that require a lot of force to move heavy objects. Most industrial geared motors incorporate fixed speed AC motors. However, some geared motors use DC motors, which are common in automotive applications in adjustable rear view mirrors and automatic seat adjustments.
Geared motor designs can mix and match motors and gears as needed to best suit application requirements. However, the housing design, assembly gears, gear lubrication, and the specific mode of integration affect the performance of the gear motor. Motor and gear reducer combinations abound: for example, right angle helical gears, parallel and planetary shaft gears can be combined with brushless DC, AC induction or permanent magnet DC motors to form a gear motor unit.
Although it is possible to combine many different motors and gears, not all of them will work for every application because certain combinations are more efficient and cost effective than others. This is why knowing the application and getting an accurate estimate of its required operating torque and speed is the basis for successfully integrating a geared motor into a system.
Gearmotors generally outperform other gearmotor combinations. More importantly, geared motors simplify design implementation because they prevent engineers from integrating motors with gears, which in turn reduces engineering costs. If the application requirements are known, engineers can order the right gear motor from a supplier directly.
Additionally, if a gearmotor is sized properly, having the correct motor and gear combination can extend the life of the design and increase the overall efficiency of the design. Geared motors can also eliminate the need for couplings and potential alignment issues that come with those components. Such problems are common when a design includes the connection of a separate motor and gear reducer, which in turn increases the potential for bearing misalignment and failure.
As we mentioned Brushless motors do not cause friction or voltage drop, which helps increase the life of the motor and improve the overall performance of the device. In conclusion, brushless motor technology is considered a very interesting advance for cordless tools, since they offer us the possibility of working with tools in a much more comfortable and productive way, offering us higher performance, longer duration as main advantages, battery life and less maintenance.