Engineering Data | Self Lubricated Technical Info

Standard Clearances, Temperatures, Speed Coefficient of Friction, Load Capacities, Wall Thickness, Surface Finish

Standard Clearances

Standard clearances for low and high temperature Spadone Self Lubricated Sleeve Bearings are show. Unusual combinations of load, speed and operating temperatures may require further review.

Temperatures

Wall Thickness

Surface Finish

Self Lubricated (Met 90) Bearings are recommended for operating temperatures up to 600°F, and are used in applications where temperatures go up to 800°. However, these levels should be considered critical and we recommend you review the details of your application with one of our technicians.
Self Lubricated bearings need suffucient wall thickness to allow for proper seating of the lubricating plugs. Standard wall dimensions range from 3/16 to 7/8 incheds for shaft diameters from 3/8 to 10 inches.
For most Self Lubricated applications, a finish of 63-125 RMS is suffucient. As loads and speeds increase, or where harder materials are used, improved surface finishes should be selected.

Speed

Submerged Applications

Speed is given in surface feet per minute:
SFPM = RPM x Shaft Diam (In.) x 0.262

Recommended speeds to Met 90 Bearings should normally not exceed 300 SFPM. However, speed must be considered in relation to the other variables of the bearings.

Load Capacities

Spadone Bearing Self Lubricated Bearings (Met 90) are ideal for submerged applications. They currently operate in water, dolvents, and many other liquids.

Our plugs are non-corrosive and the lubricating film expressed to the bearing surface and mating part helps to protect all metal surfaces from corrosive conditions.
Loads are calculated in pounds per square inch on a projected bearing area:

PSI Projected Bearing Area =

Total Bearing Load
-----------------------------------
Brearing Length * Shaft Dia.

Pressure or load capacities vary with the bronze alloy selected. For general use, Our self lubricated bearings are furnished to meet unit loadings of 1,000 to 3,500 psi. When higher loads are indicated, a higher alloy may be suggested.

Load capacity of Met-90 Self Lubricated Bearings and plates range up to 3500 - 4000 psi for slow-speed applications and 7500 psi for static loads.

Bearing Length

The optimal Self Lubricated sleeve bearing length should be 1-1/2 times the I.D.. However, in practice this rull is often violated without penalty. If dealing with a heavy load it is usually best to increase the length of the bearing, rather than increase the diameter.

Coefficient of Friction

Coefficient of Frication is often recorded in terms that have little relation to actual operating or field conditions. In an effort to close the gap between theory and reality, our self lubricated bushings have been operated in many types of applications and environments. Tests indicate the our bearings have .04 to .10 in heavy and medium load applications.

For design purposes, you should use a .10 cooeficient.

Where an application involes a higher temperature and design coefficient of .15 is recommended.