FafnirRAS1 1/8Two-Bolt Pillow Block Ball Bearing Unit, 1-1/8 in Bore, Eccentric Locking Collar

Product Description

What this part is

A Fafnir RAS1-1/8 two-bolt pillow block mounted ball bearing unit sized for a 1-1/8 in shaft. The cast-iron base housing carries a G1102KRRB wide-inner-ring insert with shroud contact seals and an eccentric self-locking collar.

Decoding the designation

RAS is the Fafnir Industrial-series two-bolt pillow block with an eccentric locking collar; the RASC designation covers the same block fitted with a concentric collar. The trailing 1-1/8 is the shaft size in inches. In the insert number G1102KRRB, G marks a relubricatable wide-inner-ring bearing with Mechani-Seal contact seals, 1102 encodes the 1-2/16 in – that is 1-1/8 in – bore, KRR denotes the wide inner ring with two contact seals and eccentric collar, and B adds a snap-ring groove and retaining ring on the outer ring.

Housing style and bolt pattern

Housing construction: two-bolt pillow block, base mounted
Bolt hole spacing J: 117.5 mm / 4.626 in centre to centre
Bolt slot width N: 14.3 mm / 0.563 in
Bolt slot length N1: 23.8 mm / 0.937 in
Base to centre height H: 42.86 mm / 1.687 in
Total length L: 157.2 mm / 6.189 in
Total width A: 42.9 mm / 1.689 in
Total height H2: 84.9 mm / 3.343 in
Foot height H1: 16.7 mm

What these specs mean in practice

A pillow block supports a shaft where the mounting surface runs parallel to the shaft axis, and the slotted bolt holes give lateral adjustment during alignment. Base-to-centre height is the dimension that fixes shaft height above the mounting face, so it is the field an existing frame is matched on. The eccentric collar locks to the shaft by cam action: the collar is turned in the direction of shaft rotation and then set with its cup-point setscrew, so drive torque tends to tighten it. The wide inner ring provides the collar seat and lets the unit run on plain commercial shafting. RAS blocks carry the same load ratings as the RAK, TAK and LAK types on a slightly higher base-to-centre height.

Published ratings and mounting data

Shaft size d: 1-1/8 in (28.575 mm)
Insert bearing number: G1102KRRB
Seal type: shroud contact seal
Dynamic load rating: 21 600 N / 4 850 lbf
Static load rating: 11 300 N / 2 530 lbf
Dimension d1: 44.1 mm / 1.736 in
Dimension B1: 48.4 mm / 1.906 in
Dimension S1: 30.1 mm / 1.185 in
Dimension T: 21.5 mm / 0.846 in
Timken SAP material ID: 100201535

Quantity and configuration

Complete pillow block unit: housing, insert bearing and eccentric locking collar. 1 Pc.

Fitting notes

The block seats on a flat rigid face parallel to the shaft, shimmed where the face is uneven, with both bolts drawn up evenly through the slots after the shaft height is set. The collar setscrew is tightened after the collar has been cammed round in the direction of shaft rotation. The insert is relubricatable through the G-series grease path.

Interchange guidance

The replacement insert for this housing is the Fafnir G1102KRRB. RASC1-1/8 is the concentric-collar version of the same block, and the RAK, TAK and LAK series share the load ratings on a different base-to-centre height; those are related sizes rather than drop-in equivalents for a frame already drilled to the RAS pattern.