SPHERICAL ROLLER BEARING PILLOW BLOCKS DESIGN AND CONSTRUCTION
DESIGN AND CONSTRUCTION Timken supplies pillow blocks equipped with either tapered bore bearings with adapters for mounting on straight shafts or cylindrical bore bearings for assembly on shouldered shafts. Timken offers a broader range of pillow blocks, including solid blocks, other than are shown in this catalog. Please reference the Timken Housed Unit Catalog (order no. 10475). Timken spherical roller bearing pillow blocks are made of split construction for convenient assembly and disassembly. These units include pry-tool slots and the exclusive Pry-Lug fulcrum that simplify bearing inspection, service and replacement. Caps
can be removed easily and quickly without damage to the bearing or housing. Timken uses a system of doweling caps and bases together at an early stage of manufacturing, so that they remain a single unit during machining. They are not interchangeable as separate parts and become precisely mated components, helping to ensure a precise fit. Timken manufactures pillow blocks in two styles: SAF and SDAF. The larger SDAF block is suggested for extreme-duty applications. Standard caps and bases are made from high-grade, stressrelieved cast iron. They also are available in cast steel. All Timken 速 split pillow blocks are designed for four-bolt mounting. Certain smaller sizes are normally furnished for twobolt mounting. These assemblies are indicated in the following tables and can be ordered with optional four-bolt base.
Bolt and Washer
Four cap bolts are used in most Timken pillow blocks in order to equalize the pressure between the cap and the base, helping to prevent lubricant loss.
LER Seal Ring
Spherical Roller Bearing
The illustration below shows all parts of a pillow block assembly that are described throughout this section.
Adapter Sleeve Steel Stabilizing Ring
Matched Cap and Base
Lockwasher
Locknut
LER Seal Ring
Fig. 26. Exploded view of a Timken spherical roller bearing pillow block, showing tapered bore spherical roller bearing, adapter sleeve, locknut and lockwasher, stabilizing ring and triple-labyrinth seals. Also shown are recesses in cap and base that form pry-tool slot, and integral fulcrum lugs in base and cap.
MOUNTING
ADAPTER VS. STRAIGHT BORE Usually a spherical roller bearing pillow block assembly is mounted on a straight shaft using a tapered bore bearing and adapter assembly. Standard commercial shafting can be used without additional machining. (Suggested inch shaft diameters are shown in table 28 on page 120.) Adapter mount also permits maximum flexibility in the axial positioning of the bearing on the shaft and will accommodate light locational thrust loads. Timken
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TIMKEN SPHERICAL ROLLER BEARING CATALOG
pillow blocks for tapered bore and adapter-mounted bearings are available in Series 225, 226, 230, 231K and 232K. Adapter-mounted spherical roller bearings require the correct removal of diametral clearance from the bearing to prevent relative rotation between inner race and sleeve or shaft. Failure to employ proper mounting procedures can cause heating and reduced bearing performance. For proper shaft mounting of adapter-type spherical roller bearings, see page 17.