Troubleshooting Locking Device
Locking Device
| 1 | Slips below the specified transmission torque value (Shaft, Hub hole ) |
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| Cause 1 | Dimensions of shaft diameter or hub hole diameter are out of tolerance | Solution | Rework the shaft or hub diameter within the recommended tolerances. |
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| Cause 2 | Surface roughness of shaft or hub hole is rougher than the recommended value | Solution | Rework at the applicable surface roughness. |
| Cause 3 | Deformed due to small hub outer diameter. | Solution | Change hub material or increase hub outer diameter |
| 2 | Slips below the specified transmission torque value (Tightening bolts ) |
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| Cause 1 | Tightening torque is less than the standard bolt tightening torque | Solution | Tighten the bolts using a torque wrench |
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| Cause 2 | Tightening efficiency of the screw is being decreased due to damage to the thread surface. | Solution | Replace the locking bolts |
| 3 | Slips below the specified transmission torque value (Machine side ) |
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| Cause 1 | Torque greater than the transmission torque of Power Lock is being applied. | Solution | Re-check the torque on the machine side and increase the size or use several units. |
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| Cause 2 | Large thrust load | Solution | Calculate the combined load and check that it is less than the transmission torque |
| Cause 3 | Large impact torque is applied | Solution | Increase size or use several pieces for greater safety factor |
| 4 | Slips below the specified transmission torque value (others ) |
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| Cause 1 | Large temperature difference between shaft and hub | Solution | Equalize the temperature of shaft and hub with a cooling device, etc. |
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| Cause 2 | Used at high temperatures, and coefficient of linear thermal expansion of shaft material and hub material are significantly different. | Solution | Change the hub and shaft material, or install a cooling device. |
| Cause 3 | No oil or grease was applied during assembly (ML and SL series, stainless steel, electroless nickel-plated models are not required ) | Solution | When assembling, apply oil or grease to the contact surface of shaft/hub, the mutual contact surface of parts such as inner/outer race, and the bolt head bearing surface and thread surface of locking bolt. |
| Cause 4 | Use of oil or grease containing molybdenum-based antifriction agent | Solution | Do not use as it changes the coefficient of friction |
| 5 | Bolt breakage |
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| Cause 1 | Over-tightening of bolts | Solution | Tighten the bolts using a torque wrench |
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| Cause 2 | Use other than dedicated tightening bolts | Solution | Be sure to use dedicated tightening bolts |
| Cause 3 | Fatigue failure due to repeated load fluctuations (Fracture surface has a beachmark pattern. ) | Solution | Replace bolts, reduce repetitive bending moments or radial loads as less as possible |
| Cause 4 | Brittle fracture (Used in acid and chemical etc. atmospheres ) | Solution | Measure the atmospheric PH value and consult us |
| Cause 5 | Operating ambient temperature exceeds 200℃ | Solution | Lower the ambient temperature below 200℃ |
| 6 | Power Lock does not fit into the shaft or hub hole |
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| Cause 1 | Dimensions of shaft diameter and hub hole diameter are outside tolerances | Solution | Rework the shaft diameter and hub hole diameter within the recommended tolerance |
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| Cause 2 | Wrong Power Lock model number | Solution | Replace Power Lock |
| 7 | Bolt does not fit smoothly into the tap for removal. |
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| Cause 1 | Damaged tap holes | Solution | Replace Power Lock |
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| Cause 2 | Damaged to bolt threads | Solution | Replace bolts |
