What is plummer block?

SN series plummer block bearing housing are un-split plummer blocks for spherical roller bearings with adapter sleeves. They are fitted with labyrinth seals. Bearing housings for shaft ends are supplied with an end cover in grey cast iron.

 
Material
SN Plummer Block Housings are manufactured as standard, from Grey Cast Iron GG25. Housings from Spheroidal Cast Iron GGG40 or Cast Steel GS45 are available for bearing applications requiring higher loading.

Loading
Plummer Block Housings are designed for loads applied vertically to the bridging surface. In these instances the permissible load is determined by the load rating of fitted bearing. Should loads be applied at other angles, checks should be carried out to determine whether the housing connecting bolts and the mounting bolts are still suitable.

Loading of the plummer block housings
If these plummer block housings are used at various directions the guide values for breaking loads will change. A factor of about 1.8 x is applied to the housings from material GGG 40 and GS 45.

Loading of the connecting bolts
Bolts to strength class 8.8 are supplied as standard for joining the housing upper and lower parts. Maximum values for radial loadings applied at various loading directions can be obtained from the adjacent table.

Torque
The fixing and connecting bolts must be tightened in accordance with guidelines. Values for relative torques can be obtained from the adjacent table.

Seals
To allow fitting of the labyrinth seal on the shaft, Perbunan cord is laid between the shaft and labyrinth seal. This also functions as a seal and allows minor axial movement of the labyrinth seal during heat expansion of the shaft. If the shaft terminates in the housing, an end cover in grey cast iron is supplied instead of the labyrinth seal.