Blocks with roller bearings

Deine Fragen / Unsere Antworte

What sheave diameter should a roller bearing block have for my rope?

The sheave diameter should be at least 6 to 8 times the rope diameter to prevent excessive bending of the rope and ensure the block runs smoothly. The exact recommendations are given in the technical specifications of each block – adhere to these, even if the block mechanically fits the rope.

Can I replace a roller bearing block with a plain bearing block if the mounting point is the same?

Generally yes, as long as the mounting type and breaking load match. Roller bearings run more smoothly under load, while plain bearings are easier to maintain and less sensitive to dirt – which block is more suitable depends on its position and the frequency of use.

How do I know if the roller bearing of a block needs to be replaced?

If the sheave runs roughly or unevenly, makes cracking noises, or turns significantly harder than before, the bearing is worn out or seized with dirt and salt. First, flush the block with fresh water and turn the sheave – if the resistance remains, the bearing should be replaced or the block renewed.

Are sealed roller bearings truly necessary for marine use, or are open bearings sufficient?

In saltwater, sealed bearings have a clear advantage because salt crystals and moisture can attack open bearings within a season. Open bearings also work in the short term at sea but require significantly more frequent care and lubrication to avoid premature failure.