Increase in frictional connection
Bearing assembly using Loctite-586
The roughness of the upper area of the surfaces to be connected should not exceed a value of Rt 65, since shear strength decreases with higher roughness levels.
The theoretical consumption for 0.1 mm layer thickness is 100 ml/m². It is advisable to calculate twice or up to three times the value when applying by hand, since hand dosages are not always accurate. During assembly, the following points are to be considered:
- Cleaning of oil and grease from the contact surfaces using a commercially available cleaning agent.
- Inactive surfaces (for example, galvanised and coated upper surfaces, aluminium surfaces, non-metallic surfaces and so on) must then be treated with the T747 activator. Loctite-586 may only be applied on non-active surfaces. Activating on both sides or applying the Loctite product on the activator can lead to premature setting (drying = a few minutes).
- Loctite should be applied on a surface with a hard brush.
- Centring devices must not come into contact with Loctite since this can make disassembly difficult further down the line. They must be coated with a separating agent, for example, with wax or grease.
- Loctite first begins to set 2 hours after being applied to the bearing. If the bolts were not able to be fully screwed during this time, gently tightening them by hand beforehand will suffice. The final hardness is achieved after 12-24 hours.
- Through and threaded holes are to be protected from Loctite.
During disassembly, the following points are to be considered:
- As already mentioned, the Loctite compound is to be applied by pressure and shear but not by tension. Separating the bearing from the companion structure is, therefore, not difficult.
- When using Loctite, the best solution is to incorporate tapped holes for jacking screws at the design stage of the companion structure. Jacking screws are absolutely necessary for large and heavy bearings and/or horizontal rotation axes, especially in the event of constricted assembly space.
- To lift the bearing off, the jacking screws are tightened consecutively until the bearing works itself free.
- For smaller bearings and easily accessible assembly locations, the careful, one-sided lifting of the bearing from various different parts of the circumference, for example from a lever rod, is sufficient.
- Under no circumstances should the bearing be hung and lifted on eyelets before the connection has been loosened, as described above.
- Cleaning the surfaces before reassembly is preferably carried out using a wire brush.