Contact

Author

Tags

Blogs

When designing products and equipment, choosing the right motor can be the difference between a successful design and one that ends up back on the drawing board. Every piece of machinery has a unique set of requirements as well as needing to be reliable and robust and getting the motor right is key.

Deciding which motor is most appropriate is reliant on the power, performance and size requirements of your industry and your particular project and therefore one of the first decisions is whether to use a brushless or brushed motor.

What is a Brushless Motor?

A brushless motor consists of a Stator and a Rotor. The stator creates a magnetic field which in turn will rotate the rotor consisting of magnets to power the machinery. Brushed motors on the other hand, use a series of carbon / precious metal brushes to transfer the current to the electromagnets.

DC brushless motors (BLDC) are essentially more reliable than a brushed motor as there are fewer parts to deal with and they are generally considered the superior of the two types. They are also considered to be the safer of the two as brushed motors can generate sparks which in certain scenarios can be hazardous.

There are two specific types of BLDC motors:

  • Fixed RPM – This has a consistent rotational frequency for each speed setting and are used primarily for equipment which will be utilized outdoors and where speed control isn’t a requirement. Brushless motors can run in open and closed loop control.
  • Variable RPM – This has a rotational frequency which can be controlled by the user. These are preferable for applications where speed control is essential.

Knowing the specific requirements of your project will make the decision easier between a brushless and brushed motor and whether a fixed or variable RPM is best.

Advantages of a Brushless Motor

There are many advantages to choosing BLDC motors for your project and these include:

  • Variable Load Speed Range – Being able to control the speed of the motor means there are many more applications for which a BLDC is suitable.
  • Continuous Torque Range – Electronically controlled motors like the BLDC are able to produce different torque and power outputs (Parvalux motors go up to 586 watts) making them more versatile. (Parvalux brushed motors can also provide high output torque and power. But there is more control with the brushed motors when connected through a controller.)
  • Long Lifespan – A brushed motor requires direct contact between the brushes and the commutator whereas brushless motors have fewer contact parts, for example there is no friction between the brushes and commutator, therefore require less maintenance through wear and tear. This means they have a longer life span than the average DC brushed motor.
  • Safer – Brushed motors have a tendency to spark due to friction with the brushes which can be a health and safety hazard in some situations. This is not a concern when using a BLDC.
    Efficient – Brushes in a brushed motor can reduce the efficiency of the motor whereas brushless motors work on 85-90% efficiency which can end up being a cost-effective option for your business.
  • Compact size – Brushless motors are able to fit a lot of power, torque and speed into a small size envelope which can be advantageous as many modern precision products not only need to be powerful and reliable, but they need to fit into a very small space.
  • Quiet Operation – The lack of means brushes that brushless motors are somewhat quieter than their brushed counterparts and produce less electrical noise and interference making them more suited to some industries such as medical, the food industry or other noise-sensitive industries.
  • Cost Effective – Although the outlay of a brushless motor can be more expensive than a brushed alternative, over the lifespan of the motor there will be cost savings in reduced maintenance fees and machinery downtime.
  • Fully Customizable – Depending on the application the BLDC is fully customizable in regard to torque and speed as well as the size envelope. The motors can be run with sensors and without sensors. Brushless motors can also have more poles than a brushed motor allowing for more precise control. Permanent magnet motors (brushed) are limited to the amount of poles they can have through the amount of brushes that can be fitted. Alternatively, there are a number of off-the-shelf options which suit a wide range of standard specifications. For more details speak with a member of the team at Parvalux.

The Disadvantages of a Brushless Motor

As with any precision instrument, there are also disadvantages as they are not appropriate for all industries and projects. The disadvantages include:

  • Speed controller – With a brushless motor (BLDC) there is a requirement to be connected to a speed controller in order to function, which can in some instances restrict application.
  • Expensive – Due to needing to be connected to a speed controller and the more complex electronic controls the BLDC motors can be more expensive than brushed motors.
  • Require Cooling – For high-power operations, BLDC motors may require more cooling systems to be put in place, which can have an impact on space and cost.
  • Maintenance – Whilst BLDC motors don’t require much maintenance when they do it can be more expensive and time-consuming due to their complex nature.

Applications of Brushless Motors

Due to the many advantages of BLDC motors over brushed motors, there are a number of applications where they are preferable, especially in industrial automation, unmanned machinery, electric vehicles and even domestic equipment. Anything which requires high speed, precision and reliability. There are so many different applications that it would be impossible to list them all, but they include:

  • Medical Industry – This can include medical analyzers, medical pumps, air pumps (ventilators), fluid pumps, stair lifts and patient hoists.
  • Warehousing Industry – In the automation of warehouses and distribution BLDC motors are essential for shuttle systems, sorting machines, AGV/AMR/AS/RS, palletizing robots, strapping, bots and conveyor belts.
  • Agricultural Industry – Automation and robotic solutions are becoming more common in the agricultural industry and can be seen in all aspects of the process from seeding, harvesting and crop maintenance through to the packing and palletizing of fruit and vegetables.
  • Travel Industry – From ticket machines to automated doors to pumps in the air conditioning BLDC motors are an essential aspect of travel from trains to planes.
  • Domestic Use – The modern home wouldn’t function without BLDC motors, and are an important aspect of dishwashers, washing machines, refrigerators and microwaves. However, they are also found in some children’s toys and even electronic toothbrushes and epilators.

The BLDC motor is extremely versatile and has the capability to power various appliances and machinery from the domestic space to an industrial factory. With high power, low noise and reduced maintenance requirements they can be suitable for numerous industries and specifications.

Whatever your project and whatever your industry we will have a motor to suit, and if we don’t our expert team can design and build custom brushless DC motors to meet all specifications. Head over to our product page or contact the team on +1/508-916-6620