Difference between revisions of "Motor types"
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(Created page with "Servo motor is a electromechanical mechanical actuator with feedback allowing precision closed loop motion control and monitoring. ==Construction== Servo motor consists two ma...") |
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Servo motor consists two main parts: | Servo motor consists two main parts: | ||
*Motor part - typically electromagnetic device that produces torque or force when driven with current | *Motor part - typically electromagnetic device that produces torque or force when driven with current | ||
| − | *Feedback device - typically | + | *Feedback device - typically electronic device that outputs measurement information such as shaft angle or velocity |
==Shapes== | ==Shapes== | ||
Servo motors and feedback devices come mainly in two shapes: | Servo motors and feedback devices come mainly in two shapes: | ||
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*Linear | *Linear | ||
Shape of motor doesn't change their electromechanical princible so both types of motors can be driven with same drives. | Shape of motor doesn't change their electromechanical princible so both types of motors can be driven with same drives. | ||
| − | ==Motor | + | ==Motor technologies== |
List of electromagnetic motor part types. | List of electromagnetic motor part types. | ||
===AC=== | ===AC=== | ||
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==Brush DC== | ==Brush DC== | ||
Brush DC (direct current) motors typically have permanent magnet stator and rotor with mechanical commutator with brushes. | Brush DC (direct current) motors typically have permanent magnet stator and rotor with mechanical commutator with brushes. | ||
| + | ==Comparison== | ||
| + | {| class="wikitable" | ||
| + | |- | ||
| + | ! !! [[Stepping motor]] !! DC servo !! BLDC servo !! AC servo | ||
| + | |- | ||
| + | | [[Closed loop]] || No || Yes || Yes || Yes | ||
| + | |- | ||
| + | | Torque control || No, inpractical || Yes || Yes || Yes | ||
| + | |- | ||
| + | | Velocity control || Yes || Yes || Yes || Yes | ||
| + | |- | ||
| + | | Position control || Yes || Yes || Yes || Yes | ||
| + | |- | ||
| + | | Available speed range || Low, Medium || Medium || High || Highest | ||
| + | |- | ||
| + | | Rated torque vs size || High || Low || Medium || Medium | ||
| + | |- | ||
| + | | Dynamic performance || Low, Medium || Medium||High||Highest | ||
| + | |- | ||
| + | | Motion smoothness || Very low to high||Medium||Medium||High to very high | ||
| + | |- | ||
| + | | Endurance || High || Medium || High || High | ||
| + | |} | ||
==Feedback device types== | ==Feedback device types== | ||
===Quadrature encoder=== | ===Quadrature encoder=== | ||
Revision as of 00:44, 18 April 2012
Servo motor is a electromechanical mechanical actuator with feedback allowing precision closed loop motion control and monitoring.
Contents
Construction
Servo motor consists two main parts:
- Motor part - typically electromagnetic device that produces torque or force when driven with current
- Feedback device - typically electronic device that outputs measurement information such as shaft angle or velocity
Shapes
Servo motors and feedback devices come mainly in two shapes:
- Rotary
- Linear
Shape of motor doesn't change their electromechanical princible so both types of motors can be driven with same drives.
Motor technologies
List of electromagnetic motor part types.
AC
Typical AC (alternating current) servo motor is a 3 phase permanent magnet syncronous machine. This type of motors are driven by 3 wires each driving one phase coil. In ideal case 3 phase AC servo is driven by sinusoidal current waveforms that are synchronized to the permanent magnet rotor.
BLDC
BLDC (brushless DC) is very similar to AC motor with only expection that it is desgined to be driven by trapezoidal current waveforms instead of sinusoidal. BLDC motors can always be driven with same drives regardless of current waveform matching.
Brush DC
Brush DC (direct current) motors typically have permanent magnet stator and rotor with mechanical commutator with brushes.
Comparison
| Stepping motor | DC servo | BLDC servo | AC servo | |
|---|---|---|---|---|
| Closed loop | No | Yes | Yes | Yes |
| Torque control | No, inpractical | Yes | Yes | Yes |
| Velocity control | Yes | Yes | Yes | Yes |
| Position control | Yes | Yes | Yes | Yes |
| Available speed range | Low, Medium | Medium | High | Highest |
| Rated torque vs size | High | Low | Medium | Medium |
| Dynamic performance | Low, Medium | Medium | High | Highest |
| Motion smoothness | Very low to high | Medium | Medium | High to very high |
| Endurance | High | Medium | High | High |
