In the world of engineering, using Frameless motors is a trend. The reason being the competitive advantages they provide. In this article today, we’ll discuss these benefits and the grounds that make frameless motors a prior choice. Let’s start with the advantages:
Advantages of using frameless motors.
Frameless motors provide a range of advantages in engineering. These include:
- Compact size because of reduced space envelop
- Lesser number of parts count
- Lightweight and easy to carry
- Frameless motors remove some potential failure modes
- Seamless integration with the machine structure
- Provision of high torque density through the multi-pole external rotor
- Offers low cogging torque
- Leaves space for cable glands
- High overload capacity
- Possibility of equipping frameless motor with thermal sensors
What are the main differences between Frameless motors and traditional housed motors?
Frameless motors are lightweight as compared to traditional housed motors. These motors are supplied as rotor-and-stator hollow-shaft kits and offer the ease of being capsulized into any housing of your choice to allow various mounting configurations. However, in traditional motors, there are so many parts such as brushes, bearing, shafts, rotors and more that are located separately in a frame, thus increasing the part count and the overall weight of the unit.
In frameless motors, there is no need to couple shaft devices to transmit the rotational movement from the motor shaft to the driven element because these motors are direct drive solutions with no bearing or shaft. Whereas, in the case of traditional motors, further bearings are needed to support the driven element of the assembly.
The life of the frameless motor is longer. As there are no brushes, there is no friction that causes wear or noise, and continuous maintenance is not necessary. On the other hand, the life cycle of traditional housed motors is lower. It generates more friction when changing polarity, and gives off heat and sparks, so the brushes end up deteriorating and must be replaced, which requires more maintenance, with the costs that it may entail.
The Frameless motor offers a better ratio between output power and size and, therefore, higher performance. On the other hand, this relationship in the traditional housed motor with brushes is lower, which causes, in turn, lower performance.
Also, the Frameless motor has a good relationship between speed and torque, which is moderate in the case of the housed motor, since increasing the speed causes friction and, therefore, decreases the torque.
Finally, the Frameless motors are a bit expensive compared to traditional motor reason being the need an electronic control for its operation, through an expensive and sophisticated circuit. However, as a result of the loss of heat that occurs in the motor with brushes, more waste of power is generated, which affects its efficiency. On the contrary, this does not happen with the Frameless motor, which is much more efficient.
What are the main applications of frameless motors?
As we have seen, a frameless motor has a good relationship between power and space. This makes it ideal for small applications where space is reduced, such as an optical pod, pan and tilt systems, radar systems, CCTV, azimuth and elevation drives, and nonetheless rotary joints for robotics and exoskeletons. In addition to these, frameless motors are a good option for applications that require low power, such as a computer fan, machine tools, mixers, or winders, etc.
So, what makes a frameless motor a prior choice?
Including all the advantages mentioned above, several reasons embrace the use of frameless motors in engineering. First of all is the ease that these motors provide to their customers, and then it is the size of the frameless motor that advocates its use. Plus, there are numerous start-up companies that offer plug-and-run operation for frameless motors and accept custom order with specialized demands to the motor.
