Both an electrical linear actuator and a multi-step lifting column make extensive use of an electrical motor. In fact, we can say that electrical motors are the heart and soul of both of them.
As we have discussed in an earlier post, a linear actuator is an intricately designed system that converts the rotational force of an electrical motor, often in the form of a rotating crank into motion in a straight line. Although linear force can also be created by pneumatic or hydraulic systems, the hard-working and precise motion of an electrical motor is what makes electrical actuators and lifting columns superior among its peers.
How do Electric Motors Work:
Well, simply put, an electric motor converts electrical energy into mechanical energy. Although most electrical actuators use a direct-current (DC) motors, we need to discuss other types of motors as well to understand how motors work overall.
Direct-Current (DC) Motors:
A DC motor has an inductor inside it that converts electrical energy into mechanical energy. This is done using permanent magnets mounted in proximity to the spinning current-carrying conductors in the rotor. The only drawback of using DC for a motor is that the farther the current travels the weaker it becomes because all the energy is applied at the origin.
If we were to use an analogy of how a DC motor works, we’d use the analogy of a soccer ball being kicked with mighty force. As the ball rolls down the field, the friction of the grass and the resistance of the wind slows it down. Similarly when direct current flow farther and farther from its source its efficacy also reduces. This is the reason why DC-motors are used in small and confined applications where there is very little distance between the source of electricity and the appliance.
Alternating-Current (AC) Motors:
An AC motor is driven by electrical current that alternates its state consistently. Using electromagnets placed around an inner core to create a rotating magnetic field to move the inner core thus converting electrical energy into mechanical energy.
Unlike a DC motor, the alternating-current motor is more like kicking a ball down the field and then another person down the field kicking it again and then another one kicking it again. This feature makes an AC motor more suitable for application where the distance between the source of electricity and the device running on it could be greater.
Why Use a DC-motor in a Linear Actuator then?
What makes DC-motors ideal for application in things like conveyors, turn-tables and yes, linear actuators is the control and instant action and reaction we get from a DC-motor. With the development of variable frequency drive (VFD) in the late 1980s, it became possible to more reliably apply variable speed control to the DC-motor. This feature is one of the main features that make it ideal for linear actuators and lifting columns.
Along with the speed control feature of DC motors that make them an ideal choice in a standing desk and other applications is that DC motors develop full torque at low speed and across the full operating range from zero to base speed, which allows it to drive constant-torque loads. Like other applications of a DC-motors like, conveyor belts, elevators, cranes, a standing desk is often stopped when fully loaded, and the full torque of the DC motor allows it to move without any delay or jerks at appointed speed without any hesitation. The smooth operation at full torque is a highly desirable feature in a standing desk or other platforms that regularly need to be moved up and down.
The simple design of DC motors also makes their service, maintenance, and control inexpensive and easily supportable.
In conclusion, these are the technical details of how electric motors, especially well designed and compact DC motors, make LoctekMotion the leader in linear actuators, and lifting columns for applications in standing desks, conference tables, storage racks or kitchen cabinets.