SE plummer block housings
SE plummer block housings are a new generation of the most popular SKF bearing housings on the market - SNL plummer block housings. With a number of new features and a stronger material grade, the upgraded housings continue to provide maximum reliability while meeting increased demands. Different housing variants and seal designs are available making the use of tailored made housings virtually unnecessary and enabling cost-effective bearing arrangements to be made. SE housings in series 2, 3, 5 & 6 will supersede SNL housings in the 2, 3, 5 & 6 series from size 507-606 up to and including SE 515-612. For size 505 to 506-605 and from size 516-613 up to and including size 532, SNL series will remain.
SE housings are split housings consisting of a cap and base. They have two holes as standard cast into the base for attachment bolts. The housings are designed on the "building block" principle to enable a wider choice of bearings and seals as well as a variety of shaft arrangements.
Features and benefits
SE plummer block housings have the following features and benefits:
Stiffer and more robust housing
The new, optimized design of plummer block housings together with their stronger material grade make SE housings more robust compared to SNL housings. And, the breaking loads are improved in some directions. With larger ribs in the base and additional material around the attachment bolt holes and in the centre of the base (fig. 1 and 2), SE housings are stiffer than their predecessors. The attachment bolts can be preloaded to locate the housing without deforming the base or housing bore.
Better heat dissipation
Enlarged ribs in the centre of the base of SE housings (fig. 2) increase the contact area between the base and the support surface compared to SNL housings. This results in improved heat flow from the bearing outer ring to the support surface.
Improved markings on the housing
The housing cap and base are matched during manufacture and are not interchangeable with the caps and bases of other housings. The marking of the unique serial number on both housing parts is easier to identify compared to SNL housings, to help avoid any mismatches (fig. 3). The designation on the housing cap has also been enhanced for readability and now contains the complete housing designation, i.e. with variant suffixes, for better traceability (fig. 4).
Dimples to locate accessories
Dimples cast into the housing cap indicate where grease fittings and condition monitoring sensors can be mounted for best results (fig. 4).
The grease fitting kit now contains tightening torque values for the cap bolts and data for initial grease fills. To simplify mounting and make alignment more accurate, lines indicating the centre of the bearing seat and housing bore axis are cast into the housing base. Dimples indicate the position for dowel pins (fig. 5). Mounting instructions are supplied with each seal pack.
SE housings have a slot between the cap and base to ease removal of the cap during dismounting (fig. 3).
Grease guiding system
For efficient relubrication from the side, SE housings have an integrated flange that guides grease from the grease fitting directly to the bearing (fig. 6). This promotes decreased grease consumption and less grease for disposal.
Grease level markings
To avoid over-filling, markings at each corner inside the housing base indicate the proper grease level for an initial 20 or 40% fill (fig. 7).
Better lubrication facilities
The hole in the housing cap for relubrication through the centre of the bearing is positioned off-centre relative to the shaft axis (fig 8).
New position of grease escape hole
The grease escape hole, on housings with suffix V, is parallel to the shaft (fig 9) for easier access after the housing is mounted. The hole is threaded and plugged.
Improved corrosion protection
SE housings are well protected from corrosion. The corrosivity category of the paint is higher than for SNL housings. SE plummer block housings are painted black with a water based paint. The paint protects the housing in accordance with ISO 12944-2, corrosivity category C3 (i.e. exterior atmospheres with moderate level of pollution or coastal areas with low salinity, interior atmospheres with high humidity and some air pollution).
SE plummer (pillow) block housings will supersede SNL plummer (pillow) block housings for sizes 507-606 up to and including size 515-612 (smaller and larger sizes remain in SNL design). In general, the product data for SE housings is similar to SNL housings (SNL plummer block housings in the 2, 3, 5 and 6 series). There are, however, three exceptions that should be taken into consideration, and these are mentioned below.The product tables for SNL housings can also be used as a reference for SE housings until updated tables are made available. When in doubt, contact the SKF application engineering service.
Initial grease fill
The initial grease fill for an SE housing is different from an SNL housing. Quantities for 20 and 40% grease fills for SE housings are identified in the instructions supplied with the grease fitting kit.
Torque values for cap bolts
The tightening torque specifications for the cap bolts for some SE housings are different from SNL housings. The torque values for SE housings are identified in the instructions supplied with the grease fitting kit.
SE housings are approximately 10% heavier than SNL housings.
Boundary dimensions are in accordance with ISO 113:1999 for two-bolt plummer block housings.
SE plummer block housings in the 2, 3, 5 and 6 series are dimensionally interchangeable with housings in the SNL series and former plummer block housings in the SN, SNA and SNH series.