Hydraulic drives, cam drives, ball screw drives or pneumatic drives can be substituted with linear motors. The linear motor is made of inductor consisting on separate cores that have concentrated polyphase.
The linear motor is also known as the rotating squirrel cage motor by experts. The only difference is that the motor is flat. Hence rather than a rotary torque from the cylinder motor, it produces linear force from the flat motor. Other than its shape and motion production, a linear motor is the same as the cylindrical one. The only thing that does not go down well with the experts though is the absence of any moving parts. However, it also has its appeal in the compact size, almost nil maintenance and noiseless operation. Also, installing and controlling the linear motor is much easier. All of these add up when you are thinking what kind of device must be created.
The rating and speed of the linear motor decides its thrust ratio. The linear motor’s speed varies from 0 to several meters each second. However, this speed is controllable. It is also easy to stop, start and reverse it. There is continuous improvement to the linear motor offering enhanced control, lower cost of life cycle, lesser maintenance and high performance. These attributes as well as the fact that they offer ease of use and control are making linear motors the choice of experts. The acceleration is high and the induction motor offers speedy response. The speed of the motor does not depend on contact friction allowing it to pick up speed swiftly.
Stepper motors are special motors that move in discrete steps. With the energizing of one set of windings, the motor moves in one direction and a step in the other direction with the other winding set being energized. There is a big advantage to using stepper motors and that is always knowing the direction or position in which the motor will move. If you know the original position, you can determine the zero position.
The angle resolution differs in different stepping motors. The most coarse stepper motor turns 90 degrees with each step. A high resolution permanent magnetic motor can only handle 18 degrees lesser than this. It is amazing how with the right kind of controller, you can run the stepper motor in half steps too!
However, there are a few complaints about the stepper motor as well, it is difficult to maneuver and it needs more power than any standard DC motor. The only thing that the linear motor going against it was that there are no moving parts.