What is Hybrid Stepper Motor : Working & Its Applications

The motor is an electrical device used to change the power (P), volts (V) & amps (A) into mechanical power, torque & speed. There are different kinds of motors available based on the requirement, in that stepper motor is one type. Stepper motor controls the speed as well as the rotation angle very accurately. These motors are BLDC motors that use an electronic driver to regulate the rotation of windings. In order to change the rotation of windings, electrical pulses are given as an input to the driver, so that motor turns one step for every pulse. Stepper motors are classified into three type’s permanent magnet, variable & hybrid stepper motor. This article discusses an overview of the hybrid stepper motor.

What is Hybrid Motor?

Definition: The combination of two motors like a permanent magnet and variable reluctance is known as a hybrid motor. The working principle of a hybrid motor is, the rotor in this motor is magnetized axially similar to a permanent magnet stepper motor, whereas the stator is energized electromagnetically similar to a variable reluctance stepper motor. So it is an actuator that changes electrical pulses to angular displacement.

As compared with other types, this kind of motor provides high torque including a less step angle and it has good dynamic property. Day by day the development in different fields like computer technology, semiconductor, and permanent magnet materials is increased. Similarly, the usage of stepper motors is also increased in different fields like robotics, industrial automation, medical, etc.

Hybrid stepper motors are available in different types namely basic, encoder, IP65, brake, integrated type including drive & controller, brake, and geared.

Hybrid Stepper Motor Construction

The construction of a hybrid stepper motor can be done using the principles of two motors like a permanent magnet & variable reluctance stepper motor. These kinds of motors are available with different step resolutions like 0.9°, 1.8° otherwise 3.6°. The standard step resolution of this motor is 1.8°.

They show high static & dynamic torque & run characteristics at extremely high step rates, so, these motors are mainly used in industrial applications. The essential parts in this motor are stator and rotor because these two connect the hybrid motor. This motor includes a tooth similar to projections. These teeth are connected in different configurations throughout the rotation

The construction of stator is similar to variable reluctance otherwise permanent magnet stepper motor. In this motor, the rotor includes two equal stacks of flexible iron that is connected to the two poles of an axially magnetized round permanent magnet.

The teeth of the rotor are connected over the poles of soft iron and this is placed on the shaft. Therefore, these teeth become like a north pole and the South Pole based on the ends, and these teeth are moved through some angle for the correct position of the rotor pole using the stator.

Hybrid Stepper Motor Working

The working principle of the hybrid stepper motor is similar to the permanent magnet motor. In the above motor diagram, it has two phases, four poles, and six tooth rotor. Once the xx’ is stimulated using DC supply then YY’ cannot excite. So the poles of the rotor will be changed from one direction to another.

Similarly, if the YY’ phase is excited, then XX’ will be turned off, so the position of poles will be changed. So the rotor in the motor will be changed into a new position in a counter-clockwise direction. If the YY’ is excited oppositely then the higher pole changed to the south & lower pole changes to the north, after that the rotor will move in a clockwise direction.
To operate the motor in the desired direction, a proper series of pulses need to given to the stator. So for each excitation, this will get protected into a new location. If the excitation is detached then this motor will maintain its locked state because of the excitation in a permanent magnet. The step- angle of this motor can be given as 30 degrees. Actually, the designing of these motors can be done using a number of rotor poles to attain high angular resolution.

Features

The features of the hybrid stepper motor mainly include

• Exact controlling of position
• The motor includes an Electromagnetic Brake
• Controlling is simple using pulse signals
• At the stopped location, this motor holds itself
• High torque can be generated through compact size

Difference between Permanent Magnet, Variable Reluctance & Hybrid Stepper Motor

The difference between these three motors is discussed below in the tabular format.

Hybrid Stepper Motor Advantages

The advantages of Hybrid Stepper Motor are as follows:-

• The torque of this motor is high
• It gives detent torque including de-energized windings
• The step length is less
• The efficiency of this motor is high at less speed.
• The stepping rate is low.

Hybrid Stepper Motor Disadvantages

The disadvantages of the Hybrid Stepper Motor are as follows

• These motors have high inertia
• This motor weight is high due to the rotor magnet within the motor
• The motor performance will be affected due to magnetic strength.
• This motor is expensive

Applications

The Hybrid Stepper Motor applications are as follows

• These motors are applicable in the production of automated devices, gauges & machines used as cutting, labeling, packaging, filling, etc.
• These are used in lane diverters, elevators, and conveyor belts.
• These are used in security devices like CC cameras
• These are applicable for consumer electronics like printing machines, scanners, digital cameras, etc.
• These motors are used in the medical field for photography of digital dental, liquid pumps, respirators, the machinery of blood analysis machinery, etc

Thus, this article discusses an overview of the hybrid stepper motor. It is very popular because it provides good performance in terms of holding torque, speed, and step resolution as compared with the permanent magnet rotor. But these are more expensive when contrasted with PM stepper motors. Here is a question for you, what are the three types of stepper motors available in the market?