Rare earth magnets and optimized rotors designed for maximum torque, and high efficiencyStators with maximum winding fill for lower temperatures, long life and maximum torqueLarge ball bearings, also optimized for short repetitive moves to ensure long life.
A stepper motor or step motor or stepping motor is a brushless DC electric motor that divides a full rotation into a number of equal steps. The motor's position can then be commanded to move and hold at one of these steps without any position sensor for feedback (an open-loop controller), as long as the motor is carefully sized to the application in respect to torque and speed.
Stepper motors, with their ability to produce high torque at a low speed while minimizing vibration, are ideal for applications requiring quick positioning over a short distance. Stepping technology allows for the use of an open-loop controller – simplifying machine design and lowering total cost compared to a servo motor system.
Hybrid stepper motors provide excellent performance in areas of torque, speed, and step resolution. Typically, step angles for a hybrid stepper motor range from 200 to 400 steps per revolution. MOONS' stepper motors include standard hybrid stepper motors, PowerPlus hybrid stepper motors and high precision hybrid stepper motors and smooth hybrid stepper motors.
AM series hybrid stepping motors are mainly used in the industrial automation industry. They match the performance of MOONS' stepper drivers and they are the recommended stepper motor type for MOONS' stepper drivers.
Step-Servo motors are specifically designed to be paired with Step-Servo drives to create motor and drive combinations that outperform traditional step motor systems.
Introduction to Stepper Motors
A stepper motor is an electromechanical device which converts electrical pulses into discrete mechanical movements. The shaft of a stepper motor rotates in discrete step increments when electrical command pulses are applied to it in the proper sequence. Stepper motors are the easiest devices for precise positioning control. They are wildly being used in various application for position and speed via all kinds of control signals such as digital, analog, communication etc.
• Basic Structure
• Operating Principles
In response to each individual control pulse and direction signal, the drive applies power to the motor windings to cause the rotor to take a step forward, a step in reverse, or hold in position. For example, in a 1.8 degree two phase step motor: When both phases are energized with DC current, the motor will stop rotating and hold in position. The maximum torque the motor can hold in place with rated DC current, is the rated holding torque. If the current in one phase is reversed, the motor will move 1 step (1.8 degrees) in a known direction.
If the current in the other phase had been reversed, the motor would move 1 step (1.8 degrees) in the other direction. As current is reversed in each phase in sequence, the motor continues to step in the desired direction. These steps are very accurate. For a 1.8 degree step motor, there are exactly 200 steps in one revolution.
Two phase stepping motors are furnished with two types of windings: bipolar or unipolar. In a bipolar motor there is one winding on each phase. The motor moves in steps as the current in each winding is reversed. This requires a drive with eight electronic switches. In a unipolar motor there are two windings on each phase. The two windings on each phase are connected in opposite directions. Phase current is reversed by turning on alternate windings on the same phase. This requires a drive with only four electronic switches. Bipolar operation typically provides 40% more holding torque than unipolar, because 100% of the winding is energized in the bipolar arrangement.
2 phase step motor with bipolar driver
2 phase step motor with unipolar driver
• Precise Positioning Control
A stepper motor rotates with a fixed step angle, just like the second hand of a clock. This angle is called "basic step angle." MOONS' offers several types of "basic step angle" as standard motors: 2-phase stepping motors with a basic step angle of 0.9° and 1.8° and 3-phase stepping motors with a basic step angle of 1.2°. Besides the standard motor, MOONS' also has stepper motors avalible with other "basic step angle." They are 0.72°, 1.5°, 3.6° and 3.75°, these motors are not listed in this catalogue, please contact MOONS' for details.
• Easy Control with Pulse Signals
A system configuration for high accuracy positioning is shown below. The rotation angle and speed of the stepping motor can be controlled accurately using pulse signals from the controller.
• What is a Pulse Signal?
A pulse signal is an electrical signal whose voltage level changes repeatedly between ON and OFF. Each ON/OFF cycle is counted as one pulse. A command with one pulse causes the motor output shaft to turn by one step. The signal levels corresponding to voltage ON and OFF conditions are referred to as "H" and "L," respectively.
• The length of Rotation is Proportional to the Number of Pulses
The length of rotation of the stepping motor is proportional to the number of pulse signal (pulse number) given to the driver. The relationship of the stepper motor's rotation (rotation angle of the motor output shaft) and pulse number is expressed as follows:
• The Speed is Proportional to the Pulse Frequency
The speed of the stepper motor is proportional to the frequency of pulse signals given to the driver. The relationship of the pulse frequency [Hz] and motor speed [r/min] is expressed as follows:
• Generating High Torque with a Compact Size
Stepper motors generate high torque with a compact size. These features give them excellent acceleration and response, which in turn makes these motors well-suited for torque-demanding applications where the motor must be started and stopped frequently. To meet the need for greater torque at low speed, MOONS' also has geared motors option.
• Frequent Starting/Stopping is Possible
• Speed VS Torque Characteristics comparetion between servo and stepper with same motor size.
• The Motor Holds Itself at a Stopped Position
Stepper motor has full torque at stand-still as long as the windings are energized. This means that the motor can be held at a stopped position without using a mechanical brake.
Once the power is cut off, the self-holding torque of the motor is lost and the motor can no longer be held at the stopped position in vertical operations or when an external force is applied. In lift and similar applications, an electromagnetic brake type motor is required.
The Step-Servo is an innovative revolution for the world of stepping motor, it enhances the stepping motor with servo technology to create a product with exceptional feature and broad capability. The Step-Servo greatly improves the performance to be much more Intelligent, Efficient, Compact, Accurate, Fast and Smooth.