Bearings and rod ends should only be removed from their packages immediately prior to mounting so that they do not become contaminated. Bearing components that could have become dirty as a result of improper handling or damaged packaging should be wiped clean with a lint-free cloth.
Spherical plain bearingsWhen mounting spherical plain bearings with a fractured or split outer ring, it is essential that the joint is positioned at 90° to the direction of load (fig. 1), otherwise service life is reduced.
The following tools are suitable for mounting spherical plain bearings:
- a mounting dolly (fig. 2) or length of tubing; the ring with an interference fit should generally be mounted first
- a dolly having two abutment surfaces (fig. 3) for simultaneously mounting the bearing on the shaft and in the housing
for larger numbers of bearings, suitable tools can be used in combination with a press (fig. 4)
When mounting spherical plain bearings, consider the following:
- Never use a hammer or pin punch to drive a bearing in place, as either could damage the rings (fig. 5).
The mounting force should never be directed through the sliding contact surfaces (fig. 6). This could damage the sliding contact surfaces and/or expand fractured or split bearing outer rings, which can cause an increase in the mounting force required.
As a rule, larger bearings cannot be mounted cold because the force required to press a bearing into position increases considerably with its size. Therefore, SKF recommends the following:
- heat the bearing before it is mounted on the shaft (fig. 7)
heat non-split housings before inserting the bearing
WARNING!Maintenance-free spherical plain bearings and rod ends must never be subjected to temperatures in excess of +280 °C (+535 °F) due to the PTFE content. PTFE is completely inert below this temperature but at higher temperatures from approx. 320 °C (605 °F) it rapidly decomposes. The fluorine compounds released during this process are extremely toxic, even in small quantities, and can cause serious injury. It should also be remembered that the material is dangerous to handle once it has been overheated, even after it has cooled.
Heat-resistant gloves should be worn when handling hot components.
Rod ends are fitted on pins and shafts in the same way as spherical plain bearings. Slight heating reduces the force required for mounting and reduce the risk of damaging associated components.
When attaching rod ends to threaded rods or extension tubes (fig. 9) a counter lock nut should be used on the rod or on the external thread of the rod end. It should be securely tightened against the abutment surface on the rod end or tube.
SKF Explorer steel/steel plain bearingsSKF Explorer steel/steel plain bearings should not be lubricated1). These bearings are lubricated at the factory under well-controlled conditions. Introducing a foreign grease will only reduce the effectiveness of the tribological system. When mounting, do not swivel the bearing to the point where grease will be displaced from the bearing.
NOTE:SKF supplies a comprehensive range of mechanical and hydraulic tools as well as heating equipment for bearing mounting and dismounting. For additional information, refer to www.skf.com/maintenance-products.
- 1)The bearings still have lubrication holes for manufacturing reasons. Do not apply grease to the bearing. Greasing or re-greasing the bearings will compromise the maintenance-free operation of the bearings and void the service life commitment provided by SKF with the original bearing.