Classification of direct drive motors
Direct drive motors are mainly divided into linear motors (linear motors), torque motors (DD motors), and voice coil motors.
Linear motor
A linear motor is a transmission that converts electrical energy directly into linear motion mechanical energy without the need for any intermediate conversion mechanism. It can be seen as a rotating motor that is cut radially and flattened. The most common types of linear motors are flat, U-groove and tubular. The typical composition of the coil is three-phase, and the Hall element realizes brushless commutation.
The linear motor can be regarded as a principle in which the conventional servo motor is cut in the radial direction and the circumference of the motor is developed into a straight line. When the coil (mover) is energized, a magnetic field is generated in the air gap between the stators, and the magnetic field lines are cut by the magnetic field and the stator permanent magnets to generate a driving force, thereby achieving linear motion.
(1) Classification of linear motors
A. Ironless linear motor (U type motor)
The mover has only coils, no magnets, no suction between the moving stators; no cogging effect, easy to achieve smoother motion and achieve higher precision.
B. Iron core linear motor (flat motor)
The mover only has a magnet inside the coil, and there is a strong suction between the moving stator, which can generate a large thrust.
C. Linear motor module
Torque motor (DD motor)
The torque motor is a special motor with soft mechanical properties and a wide speed range. The shaft of such a motor does not output power at a constant power but outputs power at a constant torque. Torque motors include: DC torque motors, AC torque motors, and brushless DC torque motors.
The DD motor belongs to a finished product, which includes the motor's mover, stator, bearing, readhead, etc. In other words, the customer can directly install and use it after purchase, similar to a linear module. Mainly used for indexing plate applications, similar to the station's transfer.
Voice coil motor
The so-called voice coil linear motor (VoiceCoilMotor) is named for its voice coil similar in structure. It has the characteristics of high frequency sound and high precision.
The voice coil motor is also a kind of direct drive motor. It is mainly used for Z-axis light load, short stroke, high frequency reciprocating motion, and also suitable for force control occasions.
