Opening Assessment
When a YASKAWA industrial robot develops new mechanical noise or vibration during motion, the first repair task is to preserve a precise description of the symptom. A noise report alone does not identify a failed component. The same observation may be influenced by the affected motion, robot pose, direction of travel, speed, load, temperature, tooling, surrounding equipment, or a change in the production sequence. Initial triage should therefore organize evidence for a competent specialist rather than attempt to assign a cause.
This guide applies to YASKAWA industrial robots of unspecified model and application while the applicable robot documentation is being identified. It addresses robot-level abnormal noise and vibration during initial triage and service handover. It does not provide model-specific alarm meanings, adjustment values, compatibility guidance, lubrication instructions, controller procedures, or component replacement instructions. It is not a substitute for the robot manual, site risk assessment, or qualified service procedure.
Record the Affected Motion
Document which movement produces the symptom. Identify the affected axis or motion as shown by the equipment documentation, and state whether the observation occurs during a single-axis movement, coordinated motion, or a complete programmed cycle. Record whether the sound or vibration appears during acceleration, steady movement, deceleration, stopping, or reversal. Note whether the symptom is present in both directions or only in one direction.
Also record the robot pose when the symptom appears. A noise that occurs only in a particular reach, wrist orientation, or work envelope region is different evidence from a symptom that follows one axis throughout its movement. The pose does not prove a mechanical fault, but it can help the reviewer compare geometry, external interference, cable routing, tooling clearance, and load position.
Capture Speed, Load, and Temperature Context
State the motion-speed context using the terminology available in the applicable robot documentation or production record. Note whether the symptom is associated with low-speed positioning, higher-speed travel, acceleration, or a specific program step. Avoid changing speed settings merely to make the symptom appear or disappear. An apparent speed relationship may reflect changing loads, motion profiles, resonance, or contact with another part of the cell.
Record the tool, workpiece, payload condition, and any relevant fixture state. Include whether the robot was empty, carrying its usual load, carrying an unusual load, or operating without the normal process accessory. A vibration that changes with load can help guide diagnostic review, but it does not by itself establish that the tool, payload, motor, reducer, bearing, or drive system is defective.
Temperature history is also relevant. State whether the robot was cold at startup, had reached its normal operating condition, or had been stopped and restarted after production. Record when the noise first became noticeable in relation to a shift, maintenance activity, tooling change, collision, relocation, process change, or extended downtime. The onset history should distinguish a gradual change from a sudden event, while avoiding assumptions about the underlying part.
Preserve Safe Evidence
Where site rules permit, preserve a short audio or video record from a safe location. The recording should show the relevant motion context, not only the sound. Record the robot identifier, date, approximate time, program or operation name, direction of movement, pose description, load state, and temperature state separately because these details may not be clear from the recording. Keep the original file and identify any edited copy.
Only competent staff should observe robot motion, and only under the equipment-specific operating procedure with required safeguards, access controls, and exclusion zones in place. Do not enter the safeguarded space to obtain a closer recording, defeat a safety function, hold a person in an unsafe position, or repeatedly reproduce the symptom. If the robot shows unstable movement, unexpected motion, visible contact, worsening vibration, or another immediate hazard, stop the observation according to site procedure and escalate it.
Use Reasoned Diagnostic Branches
If the symptom follows one axis or one motion direction, the reviewer may compare axis-specific mechanical, drive, feedback, cable, load, and external-interference possibilities. This observation narrows the review area but does not identify a failed component. If the symptom changes with pose, the reviewer may examine geometry, load distribution, tooling clearance, and motion-dependent mechanical conditions. This still does not prove contact, bearing damage, reducer wear, or calibration error.
If the symptom changes with temperature or operating duration, the reviewer may compare cold-start and warmed-up behavior under controlled, documented conditions. That result establishes a repeatable operating relationship only; it does not establish a particular thermal or electrical cause. If the symptom appears across several motions or under different loads, the review may need to include the robot installation, tooling, workpiece, cell structure, and process sequence rather than the robot body alone.
Service Handover and Repair Conditions
The handover should include the robot model and serial information when available, controller identification when safely accessible, affected operation, motion and pose, direction, speed context, load and tooling state, temperature state, onset history, frequency, recording references, visible observations, recent changes, and the action already taken. Include relevant alarms or event records only as documented by the equipment, without interpreting their meaning outside the applicable manual.
Repair should proceed only after the responsible specialist has reviewed the evidence, confirmed the applicable documentation, assessed safety and production risks, and defined the required inspection or test procedure. A component should not be ordered or replaced solely because a noise resembles a familiar failure.
Verification After Repair
After corrective work, verification should use the equipment-specific procedure and an agreed comparison with the original complaint. Confirm the affected motion, pose, direction, speed context, load state, and temperature state. Check for abnormal noise or vibration, unexpected motion, visible interference, and any new recorded condition. Document the operating state and result. A successful verification shows that the reported symptom was not reproduced under the defined conditions; it does not certify every function of an unspecified robot or eliminate the need for scheduled inspection and manufacturer documentation.
Cover adapted from original image by URINC (CC BY-SA 3.0; source and attribution)
