POBCO-B Wood and POBCO Plastics

BEARING CLEARANCES

POBCO bearings are normally furnished with an installed clearance between the bearing and its journal, as shown in the table to the right. This provides the proper running clearance under actual operating conditions. Bearings also can be furnished with no clearance when the user desires to ream after installation in housing. Reaming has no effect on the self-lubricating action of POBCO non-metallic bearings.

Shaft Diameter

Clearance

Bearing Operating Conditions

Roll End Bearing Operating Conditions

Dry

Wet

Dry

Wet

to 1/2"
1/2" to 1"
1" to 1-1/2"
1-1/2" to 3"
3" or larger

.002-.010
.004-.015
.006-.020
.010-.025
.015-.030

.010-.030
.015-.040
.025-.050
.030-.060
.030-.070

.015-.030
.015-.030
.015-.030

.015-.045
.030-.055
.040-.060

*For plastics - Dry clearance is standard

Press Fits

POBCO sleeve, flange and roll end bearings are normally furnished with oversize outside diameters to insure firm retention in their housings, as shown in the table. The leading edge of the housing must be chamfered to prevent shearing the outside diameter of the bearing during installation.

Normal bearing tolerances are shown in the following table. Closer tolerances are available.

Nominal OD

Press Fit

to 1/2"
1/2" to 1"
1" to 1-1/2"
1-1/2" to 3"
3" or larger

.003-.006
.004-.008
.005-.010
.006-.012

Required Material Information

(For Bearings, Rectangular Wear Strip, Curved Wear Strip and Chain & Cable Guides)
To signify POBCO Materials add code letters before the first hyphen in the part number.

For POBCO-B (lubricant-filled hardwood) add B
For POBCO Plus (fluid lube-filled UHMWPE) add P
For POBCO Ultra-D (UHMWPE) add U

Required Bearing Information

To complete the bearing part number, indicate the bearing clearance by adding the appropriate suffix from the table below.

D -Dry operating condition clearance (for POBCO-B only)
W -Wet operating condition clearance (for POBCO-B only)
N -No clearance (for reaming at installation)(for all materials)

Examples:

Sleeve bearing 1/2" x 3/4" x 11/4" for dry operating conditions: SLB-0812020-D
Flange bearing 5/8" x 1" x 1-1/2" no clearance (for reaming at installation): FLU-1016024-N
Two piece spherical bearing, 62mm sphere, 1-1/4" shaft, wet operating conditions: PSBB-206228-TP-W

Roll End Bearings

To complete the roll end bearing or conical roll part number, add the shaft size in sixteenths (two digits) followed by the bearing clearance suffix.
(1/2" shaft = 08, 3/4" shaft = 12)

Examples:

Standard roll end bearing for 21/2" diameter 16 gauge tubing with 5/8" shaft: STP-40T16-10
Blind-bore roll end bearing for 2" schedule 40 PVC pipe with 9 /16" shaft operating in a wet condition: BLB-32P40-PVC-09W
Conical roll for 1/2" shaft and dry operating conditions: COB-327272-08D

Wear Strip Tolerances

POBCO Ultra-D, POBCO plus, and POBCO-B Hardwood

Normal Commercial Tolerances
Thickness:
1/8"-3/16" +/- 15%
1/4"-3/8" +/- 10%
1/2" & over +/- 10%
Width: +/- .030"
Length: -1/2"+1"

Normal Machined Tolerances
Thickness:
1/8"-3/8" +/- .020"
1/2" & over +/- 10"
Width: +/- .010"
Length: +/- .030

Closer Tolerances are available. For other material tolerances, please inquire. Please specify Commercial or Machined or other Tolerances.

Required Wear Strip Information

To complete the wear strip part number, add the length in inches as shown by the examples below.

Rectangular wear strip 1/2" thickness x 2" width x 60" length: WSB-0832L60
Chain Guide, Profile 2, 2060 chain, 120" length:P2P-2060L120

Allowances must be made to eliminate the possibility of binding caused by machine and material expansion when designing wear strip.