We all know that the main function of any motor is to convert electrical energy into mechanical energy, speed, and torque. Therefore, the special feature of stepper motors is that they have the ability to precisely manage the control related to the functional angle and speed. Let’s start with the concept of stepper motors, and then continue to understand hybrid stepper motors. Therefore, stepper motors are also called stepping motors and belong to the category of brushless motors, which divide a complete rotation into equal phases. In this way, the position of the motor can be instructed to rotate and stop on any phase having no use of a position sensor for the feedback.
All motors convert electricity, voltage, and ampere into mechanical power, torque and speed. The unique feature of stepper motors is that they can control the speed and rotation angle very accurately. The stepper motor is a brushless DC motor, therefore, an electronic drive commutating winding is required. To control the rotation, electrical pulses are input to the driver, and the motor rotates one step for each pulse. Since the motor can run in an open-loop without feedback, the good stability of the motor makes the control circuit simple.
Hybrid stepper motor definition
Taking advantage of the combination of variable reluctance and a permanent magnet, a stepper motor is designed. In a similar aspect of permanent magnet motors, hybrid stepper motors also have permanent magnets present in the rotor teeth. This pair of teeth is called a cup-circulating rotor. They are magnetized to produce a pair of magnetic poles, namely the north and south poles. In addition, there are hybrid control-type stepper motors that provide enhanced performance and response. In addition to the open-loop system, it also provides the advantages of a closed-loop system.
Through this kind of motor, the position of the motor can be continuously observed, so that the driver can switch between closed-loop and open-loop lop according to the situation. In general, the function of the motor is to observe and control the application is similar to a normal stepper motor. When there is an error between the position of the motor and the command due to excessive load, the system automatically turns to a closed-loop like a servo motor. This will update to the exact speed level and position, thereby maintaining the desired position.
Hybrid stepper motors are composed of variable reluctance and permanent magnet motors. The rotor of the hybrid stepper motor is axially magnetized like a permanent magnet stepper motor, and the stator is electromagnetically excited like a variable reluctance stepper motor. Both the stator and rotor are multi-toothed.
Hybrid stepper motors have an axially magnetized rotor, which means that one end is magnetized as a north pole and the other end is magnetized as a south pole. A toothed rotor cup is placed at each end of the magnet, and the cup is offset by half the tooth pitch.
Hybrid stepping motors look a lot like ordinary motors. One major difference is the assembly of the rotor and stator.
Advantages
The advantages of hybrid stepper motors are as follows:
Every step that occurs in the motor is the smallest
It provides increased torque
The motor provides high braking torque and has a de-energized winding
It can improve performance even at the lowest speed
Minimum stepping speed
Disadvantages
The disadvantages of hybrid stepper motors are as follows:
The inertia of the motor is large
Due to the presence of rotor magnets, the design, weight, and structure of the motor are more complicated
Changes in magnetic strength will affect the reliability and efficiency of the motor
Compared with variable reluctance motors, hybrid stepper motors are more economical.
