5 Mistakes to Avoid with Servo Motor Maintenance and Repair
Servo motors, like any mechanical equipment, require periodic checks and servicing to ensure they function correctly. Regularly scheduled maintenance not only prolongs the life of the servo motor but also enhances its efficiency and reliability. This involves cleaning the motor to prevent dust and debris buildup, inspecting for wear and tear, and lubricating moving parts. Failure to perform these tasks can lead to overheating, increased friction, and eventually, motor failure.
While maintenance schedules are generally followed, there are other areas often overlooked when it comes to ensuring the performance and longevity of your servo motors. Here are five common mistakes to avoid when it comes to servo motor maintenance and repair:
1. Failure to Document
When servicing the servo motor, it is critical to maintain encoder alignment integrity. Encoders must be aligned with sufficient accuracy so that the motor can be correctly commutated by the drive and can provide the torque and velocity that is commanded by the controller for the application. Even slight alignment variations can cause the motor to run poorly or not at all.
Additionally, ensure that all control parameters and settings are correctly configured according to the application requirements. If changes are made to the system, recheck the settings and connections to prevent potential issues.
Recording and documenting is important. Before jumping into repairs, document the steps and record incoming alignment. This helps to ensure proper reassembly.
7 Steps to Servicing a Servo Motor
Without Compromising Encoder Alignment
Similarly, it’s recommended to record two lockups for servo motor alignment (for example, both positions +U-V and +U-W) to ensure accurate alignment. This data helps diagnose misalignments and provides a reference for restoring optimal performance. It prevents further mechanical stress and potential damage, ensuring efficient and reliable motor operation post-repair.
Recording two lockups is recommended as this causes the motor shaft to go to a second position and allows the technician to confirm that the motor is rotating the correct direction. Similarly, wrong directional rotation indicates an issue with the wiring.
2. Ignoring “Minor” Issues
Servo motors are susceptible to performance issues due to excessive loads, insufficient ventilation, or electrical faults. Ignoring signs, such as overheating, unusual noises, reduced performance, or increased energy consumption, can result in irreversible damage.
Overheating, for example, can degrade insulation materials, damage windings, and ultimately cause motor failure. To prevent this, ensure that the motor is adequately ventilated and that its load is within the specified limits. Additionally, implement temperature monitoring systems to detect overheating early. If overheating is detected, identify and rectify the underlying cause immediately.
3. Using Aftermarket or Poor-Quality Parts
Using non-recommended or poor-quality parts during repairs or replacements can compromise the performance and lifespan of servo motors. Aftermarket or substandard parts may not meet the manufacturer’s specifications, leading to excessive wear, misalignment, and even catastrophic failure. Using poorly made custom cables, for example, often results in faulty connections either with the power connection or with the feedback device.
Always use genuine or high-quality parts that meet the OEM specifications. Referencing the manufacturer’s guidelines and sourcing parts from reputable suppliers can help ensure compatibility and reliability.
4. Improper Handling and Storage
Proper handling and storage practices are essential to maintaining the integrity and functionality of servo motors. Failure to do so can lead to physical damage and operational issues. Dropping a motor or exposing it to harsh environmental conditions, such as moisture or extreme temperatures, can cause mechanical damage and affect its performance.
When handling servo motors, use appropriate lifting techniques and equipment to prevent physical damage. For storage, ensure the motors are kept in a clean, dry, and temperature-controlled environment to protect them from corrosion and other environmental hazards.
7 Requirements for an In-House Servo Motor Repair Environment
5. Running Equipment Prior to Repair Validation
Running the motor prior to validating repairs is a common problem and can ruin the equipment. We recommend first using the TI-5000JX to verify the encoder or resolver and confirm proper counting, and check for encoder error codes.
We recommend a systematic two-step process to identify and resolve issues.
Step 1: Check Inputs
The first step is to verify that all inputs are correct and functioning. This includes checking power supply voltages, signal inputs, and any other relevant data or control inputs. This is crucial as incorrect inputs often lead to system malfunctions or incorrect outputs.
Step 2: Check Outputs
Next, examine the outputs to ensure they are correct and match the expected results. Incorrect outputs indicate an issue within the system. This step may involve checking for signal integrity, ensuring that output devices are functioning properly, and verifying the system’s response.
Following these two steps isolates problems more effectively, determining whether issues are due to faulty inputs, incorrect outputs, or a problem within the system’s internal processing. This process helps in narrowing down the possible causes of a malfunction, making it easier to identify and fix the root cause.
Proactive Servo Motor Maintenance
Maintaining and repairing servo motors effectively requires attention to detail and adherence to best practices. By avoiding the common mistakes outlined in this blog, you can ensure the longevity and optimal performance of your servo motors. These guidelines will help prevent costly repairs and downtime, ultimately contributing to the efficiency and productivity of your operations.
And remember to take advantage of available resources to assist with testing and repairing servo motors and ensuring proper encoder alignment. In addition to servo testing literature, Mitchell Electronics, Inc. offers expert support services and servo motor training. Using the support form on the page expedites the process and ensures optimum results.
Questions? Contact us to discuss your servo motor repair concerns.
You can also download The Quick Reference Guide to Servo Motor Maintenance and Repair. Inside this in-depth guide, you’ll find insights into:
- Diagnosing common servo issues
- Understanding common servo error codes
- Knowing what you can fix in-house and what needs to be sent out for repair
- Identifying tools you’ll need to make repairs in-house
- Learning what makes a successful repair shop
