Advantages of DD motor

Servo motors usually run unstable due to insufficient torque and swing during operation at low speeds. Gear deceleration will reduce efficiency, loosening and noise will occur when gears are meshed, and increase the weight of the machine. In actual use, the rotation angle of the index plate during operation is generally within a circle, and a large instantaneous starting torque is required. The DD motor, without a reducer, has a large torque and maintains precise and stable operation at low speeds.

The characteristics of DD motor

1, The structure of the DD motor is in the form of an outer rotor, which is different from the AC servo of the inner rotor structure. The number of magnetic poles inside the motor is also relatively large, resulting in greater starting and turning torque.

2, The radial bearing used in the motor can bear great axial force.

3,The encoder is a high-resolution circular grating. The circular grating resolution used by jDS DD motor is 2,097,152ppr, and it has origin and limit output.

4, Due to the high-precision measurement feedback and high-level manufacturing process, the positioning accuracy of the DD motor can reach the second level. (For example, the absolute accuracy of DME5A series is ±25arc-sec, and the repeated positioning accuracy is ±1arc-sec)

DD motor and servo motor + reducer have the following differences:

1: High acceleration.

2: High torque (up to 500Nm).

3: High-precision, no shaft looseness, high-precision position control can be achieved (the highest repeatability is 1 second).

4: High mechanical accuracy, the motor axial and radial runout can reach within 10um.

5: High load, the motor can bear up to 4000kg of pressure in the axial and radial directions.

6: High rigidity, very high rigidity for radial and momentum loads.

7: The motor has a hollow hole for easy passage of cables and air pipes.

8: Maintenance-free, long life.

Feedback

DDR motors usually use optical incremental encoder feedback. However, there are also other feedback types to choose from, such as: resolver encoder, absolute encoder and inductive encoder. Optical encoders can provide better accuracy and higher resolution than resolver encoders. Regardless of the size of the high-phase DDR motor, the grating pitch of the optical encoder grating ruler is usually 20 microns. Through interpolation, very high resolution can be obtained to achieve the accuracy required by the application. For example: DME3H-030, the grating pitch is 20 microns, there are 12000 lines per revolution, the standard interpolation magnification is 40 times, and the resolution per revolution is 480000 units, or the resolution with grating as feedback is 0.5 microns. Using SINCOS (analog encoder), after 4096 times of interpolation, the resolution that can be obtained is 49152000 units per revolution, or the resolution with grating as feedback is 5 nanometers.

By Jessica