Pressure & Velocity
Ratings:
Max. PV ............. 50,000
Max. P .................
2,000 Max. V ................. 1,200
PV Calculation:
PV is a means of measuring the performance capabilities of
bearings. P is expressed as pressure or pounds per square inch on the area
of the bearing. V is velocity in feet per minute of the wear surface
(surface feet per minute).
For sleeve bearings, the surface speed is .262 (pi÷12) x
RPM x shaft diameter in inches. P is equal to the load on the bearing in
pounds divided by the projected area in square inches. For sleeve
bearings, the projected area is the length x the inside diameter of the
bearing. PV is then obtained by multiplying P x V as shown in the
following example:
3/4" shaft @ 341 RPM, 90 lb. total load, bearing
length 1".
V = .262 x RPM x shaft diameter, or .262 x 341 x .750 = 67
sfpm.
P = total load ÷ projected area (area = .750 x 1.0 = .75
in.), or 90 lbs. ÷ .75 = 120 psi.
PV = 120 psi x 67 sfpm = 8040 PV
Piloted Driver:
For proper insertion of sintered bronze bearings
Suggestions for inserting sintered bronze bearings using a piloted driver:
1. Shoulder diameter should be larger than bearing.
2. Pilot length should exceed bearing length.
3. Pilot diameter should be approximately .0003 larger than desired bearing ID after
insertion.
4. Edge of housing bore should be broken to prevent shearing of bearing OD during
insertion
REF:
Housing Bore - 1.2495/1.2505
Shaft Dia. - .9995/1.0000
Bearing Size - 1.003/1.004 ID x 1.253/1.254 OD.
Pilot Dia. - 1.0013 - 1.0015
Even though your available bearings may vary slightly in bore size, the proper use of a
piloted driver for insertion will assure correct shaft clearance after assembly.
Depending on the bore size, bearings having dimensional differences of up to .003"
can be interchanged.
Comparable
specifications are: