As a high-precision power source, servo motors usually need to be used with reducers. This combination is very common in industrial automation, robotics, CNC machine tools and other fields. What key advantages do reducers bring to servo systems? This article will comprehensively analyze the deep reasons why servo motors must be equipped with reducers from the principle to the application scenario.
I.Torque amplification: Breaking through the physical limitations of motors
When the servo motor is directly driven, the output torque is limited by the motor size and electromagnetic design, and the reducer can amplify the torque through the speed ratio i (output torque ≈ motor torque × i × efficiency), and when it is necessary to drive a large inertia load, the reducer can increase the torque by 10-100 times to avoid motor overload.
II.Speed matching: Optimizing work efficiency
The rated speed of servo motors is usually 3000-6000rpm, while the actual load demand is often lower: the reducer reduces the motor speed to the required range of the load to avoid the motor from running in the inefficient working area for a long time.
III.inertia matching: Improving system responsiveness
When the load inertia is greater than the motor rotor inertia × 3, the system response slows down. The reducer reduces the load inertia by i² times when converted to the motor shaft
IV. Improved accuracy: Make up for the shortcomings of the motor
1. Enhanced resolution:
When the 17-bit encoder motor is directly driven, the corresponding displacement of a single pulse may be too large
The speed ratio 10 reducer increases the displacement resolution by 10 times
2. Backlash compensation:
High-precision planetary reducers (such as Sumitomo P1 level) have a backlash of ≤1 arc minute
It is equivalent to reducing the positioning error of the motor itself by dozens of times
V. Mechanical protection: Extend equipment life
1. Overload buffer: The reducer gear set can withstand instantaneous 300% torque shock
2. Vibration absorption: Gear meshing filters high-frequency vibration (compared with direct drive vibration spectrum)
3. Convenient maintenance: When damaged, only the reducer needs to be replaced to protect the expensive servo motor
VI. When can the reducer be used without a reducer?
Direct drive solutions can be considered in the following scenarios:
Load torque < rated torque of the motor (such as small indexing plates)
Requires extremely high dynamic response (such as voice coil motor applications)
Extremely limited space (such as medical micro devices)
VII. Serious consequences of improper selection
Speed ratio is too large: long-term low-speed operation of the motor leads to overheating
Speed ratio is too small: insufficient torque triggers AL.020 overload alarm
Insufficient accuracy: The reducer with a backlash of 5 arc minutes makes the robot’s repeated positioning error > 0.1mm
In summary, servo motors are matched with reducers to meet the needs of diverse industrial applications. Reducers can effectively adjust the speed, increase torque, and improve the control accuracy and stability of the motor. From automated production lines to precision instruments and equipment, the combination of reducers and servo motors plays a key role. In actual selection and application, it is necessary to reasonably match the parameters of the two according to the specific working conditions, give full play to their synergistic advantages, and provide solid guarantees for the efficient and precise operation of industrial production.