2 principal parameters are important when using self-lubricating bearings:

1. Shaft gliding speed

2. The specific load

1. Shaft gliding speed

2. The specific load

Parameters P and VUnder certain conditions these 2 parameters correlate as follows:

**P** Parameters P and VUnder certain conditions these 2 parameters correlate as follows:** X****V** The Shafts linear speed in m/sec ** = 18** The max. value for oil-steel and bronze

This value can possibly be considerably increased according to the specific conditions:shaft hardness and finish – set-up - runout – extra lubrication

** 1st ex. **

How great is the permitted load for a bearing with Ø int. 20 mm,length 25 mm and shaft speed of 1000 °/m?

**Solution:**

P = 18 kp pr. cm2 of the projected surface.

The projected surface is:2 cm (Ø int.) x 2.5 cm (length) = 5 cm2

The max. permitted load on this bearing is:18 kp/cm2 x 5 cm2 = 90 kp

**2nd ex.**

Determine the necessary length of the bearing given the following conditions: total load 175 kp.

Shaft diameter 20 mm, 500 o/m.

** Solution:**

The total load, which is 175 kp, thus requires a projected area of:175 kp: 35 kp/cm2 = 5 cm2 = 500 mm2

Thus the necessary length is:

500 mm2 : 20 mm = 25 mm

**NB:**

Extremely small or extremely large speeds cannot be extrapolated from the graph.

Consult us for such instances.