The motor shaft (rotor shaft) of a stepper motor does not rotate continuously, but intermittently rotates at a certain rotation angle.

For example, a clock with a second hand that moves once per second to record time uses a stepper motor to control the second hand to turn every second6°To achieve.

So what kind of structure does a stepper motor use to make the shaft only rotate a certain angle?

The secret lies in the pulse signal. Pulse signal is an electrical signal that repeatedly performs power on and power off, with power on and power off occurringoneCount as secondaryoneA pulse. The stepper motor mechanically and accurately controls the rotation angle and speed of the shaft based on this pulse signal.

Types of stepper motors①(Classified by rotor structure)

Stepper motors are classified according to the structure of the motor shaft (rotor)threeMajor categories.

PMType（Permanent Magnet Type: Permanent magnet type)

The rotor uses permanent magnets. However, it is not possible to set a precise rotation angle (step angle).

VRType（Variable Reluctance TypeVariable Magnetic Resistance Type

The rotor uses a gear shaped iron core. Fine rotation angles can be set.

HBType（Hybrid Type: Mixed type)

The rotor uses permanent magnets and gear shaped iron cores. Simultaneously possessingPMType andVRDue to its advantages, it is widely used for various purposes. In addition, all stepper motors developed and manufactured by Aspina areHBType.

HBWorking principle of type stepper motor

The rotor structure uses two iron cores to clamp a cylindrical permanent magnet, with the iron cores offset by half a tooth pitch and installed concentric on the rotor shaft. The structure is to rotate a certain step angle according to the pulse signal. 1.8°Step angletwophaseHBStepper motor connected tooneRotate during one pulse1.8°Therefore, obtained360°/1.8°=200That means the motor shaft needs to rotate oncetwo hundredA pulse.

Types of stepper motors②(Classified by the way current flows through the coil)

In addition, according to the way current flows through the coils inside the motor, it can be divided into the following two types.

Unipolar type

oneA type where only unidirectional current flows through a coil. The control circuit is simple, but it cannot achieve the high torque of bipolar type.

Bipolar type

oneThe type of bidirectional current flowing through a coil. The control circuit is more complex than the unipolar type, but it can achieve higher torque.

What is a stepper motor driver

The combination of stepper motor and stepper motor driver is used. The rotation angle and speed of the stepper motor are controlled by the stepper motor driver receiving pulse signals from the controller.

twoMixed type
stepping motor driver

Characteristics of stepper motors

Stepper motors have the following characteristics compared to other motors.

advantage

• The rotation angle is proportional to the number of pulses in the digital input, making it easy to control the position (rotation angle)

• Can perform low-speed rotation

• Open circuit (no feedback) can be used to achieve position control

• Excellent self retention when stopping

shortcoming

• Need to drive circuit

• Unexpected fluctuations in load may lead to step loss

• Excessive vibration and noise

The purpose of stepper motor

The stepper motor has excellent stopping accuracy, high torque at medium and low speeds, and sharp responsiveness, making it suitable as a power source for various drive systems that require high-precision control.

• manufacturing equipment

• medical equipment

• Inspection and analysis equipment

• ATM

• vending machine

• Ticket vending machine

• copier

• robot

• Optical disc drive（Blu-ray/DVDEtc.)

• laser printer

• digital camera

• Air conditioning air guide plate

• gaming equipment

Using stepper motors to solve customer problems

We not only provide motor units, but also system products ranging from drive and control systems to mechanism design for the stepper motors of Aspina. We provide a range of services from trial production to mass production and after-sales support.
We will provide the best solution according to the functions and performance required by various industries, uses, and customer products, in conjunction with the customer's production system.

We not only provide services for customers with clear needs and specifications, but also offer support from development to mass production for customers who encounter various difficulties. Please feel free to inquire.

I don't know what kind of motor is needed

• "We are still in the early stages of new product development and have not yet produced specific specifications and design drawings. But in order to accelerate the future development process, we hope to receive some suggestions on the motor aspect."

• "There are no experts proficient in motors in the company, and there is a lack of motor knowledge required to achieve ideal operation."

The comprehensive design of the motor and its surrounding parts is too difficult

• "We want to invest our company's resources into product planning and the design and development of core technologies. Is there any company that can fully undertake the design and development of motors and their surrounding parts in addition to this?"

• "Modifying the motor requires modifying the design of other structural components, which may require a lot of time and effort."

There are no products that meet the intended use in the existing products

• "We wanted to find customized motors designed based on our company's products, but were rejected by the cooperating motor manufacturer."

• "We want precise control of the motor, but the existing motor does not support it. Can we just give up?"