The valid accident prevention regulations and the stipulations of DIN EN 818-7 and DIN 685 part 5 must be observed during all maintenance work. In the same way the assembly, disassembly, commissioning, operating and maintenance instructions of the lifting equipment manufacturer must be observed at all times.
Through a regular lubrication of the round steel chain a 15-20 times higher number of cycles can be obtained than with a dry, unlubricated chain. We recommend to lubricate the chain along its entire length before putting into operation. It must be ensured that all chain links are lubricated. No chain link may be overlooked, as this can lead to premature wear. During lubrication, ensure that the lubricant penetrates into the chain links most susceptible to wear. Change-over link shoulld be lubricated especially careful. Change-over links are those links which stop on, resp. immediately at the inlet of the drive and reversing wheels at constant stroke when switching from lifting to lowering. These chain links are charged especially heavy by dynamic vibrations and have therefore to be lubricated carefully in shorter intervals. The choice of a suitable lubricant is dependent from the operating place and the existent environment conditions. An appropriate lubricant recommendation can be inquired at RUD.
Chain adjustment must be checked regularly, especially during running-in periods for new chain and/or in the case of extensive chain length. Tensioning should only be as much as necessary for the chain under normal operating conditions. In multi-chain devices, all chain strands must be tensioned equally. Unnecessary high tensioning force reduces lifetime.
Inspecting the chain drive:
The chain must be inspected at regular intervals, but at least once annually, in accordance with the stipulations of DIN 685 part 5 and the valid accident prevention regulations. As the frequency of use increases, the inspection intervals must be reduced and adjusted to the prevailing operating conditions as wear, corrosion, the effects of the heat and greater susceptibility to faults occur. As long as no experience-based values are available for wear under the actual operating conditions, an inspection must also be carried out every time the chain is relubricated. The inspection includes detecting external fault, deformation, cracks, wear and corrosion.
During inspection, the chains must be examined along their entire length, including the hidden parts. If the lifting equipment is frequently used with a constand lifting distance or if switchover from upward to downward often takes place in the same area, a particularly thorough inspection and lubrication is required in this switch-over area. Together with the chain the wheels, chain guide and fastening parts should be inspected for damage, corrosion, abnormal area of wear or other defects. Particular attention should be paid to the condition of all bolts and safety components. It defects are discovered they must be repaired without delay.
Replacement state of wear of the round steel chain:
The chain must be replaced if the average wire diameter dm has been reduced due to wear by more than 10% of the nominal thickness at any point on the chain link. The average wire diameter dm=(d1+d2):2<=0.9d, whereby the average wire diameter dm is calculated from two individual values d1 and d2 measured rotated through 90° with respect to each other. The chain must be replaced if a single chain link is permanently lengthened or if the inner pitch t of the individual link has increased in size by more than 5% as a result of wear. The chain must also be replaced if the inner pitch 11t has increased in size by more than 2% along a measuring section of 11 chain links.
Replacement state of wear of the driving and reversing wheels:
If the chain is run up to the replacement state of wear of 2% pitch enlargement (over 11t) on the wheels, the driving and reversing wheels must be inspected carefully. Damaged wheels have to be replaced together with the chain. If no material cavities and only slight running traces at the teeth flanks and supports on the driving and reversing wheels become apparent, the wheels do not have to be replaced.
For fast identification of wear state by external gauging of 11 pitch + 2 diameter
- At pitch increase by wear or distortion
- gauging at loaded chain strand possible, too
- gauging device with simple design
- Easy handling
Specially developed for the practitioner for quick detection of the replacement state of wear via external gauging (11t + 2d)
- in case of increases in pitch due to wear or warping
- Measurement can be made
- at the loaded chain strand
- Measurement device with
- simple setup
- Easy handling
the measurement device is calibrated for the various hoist types of a manufacturer (both national and international brands) and determines the replacement state of wear.