Stepper motors are known for their accurate positioning capabilities and high torque delivery at low speeds, but they require careful sizing to ensure the motor matches the load and application parameters, to minimize the possibility of lost steps or motor stalling. Adding a gearbox to a stepper motor system can improve the motor’s performance by decreasing the load-to-motor inertia ratio, increasing torque to the load, and reducing motor oscillations.
Advantages
- Low cost for control achieved
- High torque at startup and low speeds
- Ruggedness
- Simplicity of construction
- Can operate in an open loop control system
- Low maintenance
- Less likely to stall or slip
- Will work in any environment
- Can be used in robotics in a wide scale.
- High reliability
- The rotation angle of the motor is proportional to the input pulse.
- The motor has full torque at standstill (if the windings are energized)
- Precise positioning and repeatability of movement since good stepper motors have an accuracy of 3–5% of a step and this error is non-cumulative from one step to the next.
- Excellent response to starting/stopping/reversing.
- Very reliable since there are no contact brushes in the motor. Therefore, the life of the motor is simply dependent on the life of the bearing.
- The motors response to digital input pulses provides open-loop control, making the motor simpler and less costly to control.
- It is possible to achieve very low-speed synchronous rotation with a load that is directly coupled to the shaft.
- A wide range of rotational speeds can be realized as the speed is proportional to the frequency of the input pulses.
Applications
As the stepper motor are digitally controlled using an input pulse, they are suitable for use with computer controlled systems.
They are used in numeric control of machine tools.
Used in tape drives, floppy disc drives, printers and electric watches.
The stepper motor also use in X-Y plotter and robotics.
It has wide application in textile industries and integrated circuit fabrications.
The other applications of the Stepper Motor are in spacecrafts launched for scientific explorations of the planets etc.
These motors also find a variety of commercial, medical and military applications and also used in the production of science fiction movies.
Stepper motors of microwatts are used in the wrist watches.
In the machine tool, the stepper motors with ratings of several tens of kilowatts is used.
