Friction Sealing

The lADC code should be interpreted as shown in the following examples (1) 124E—a soft formation, sealed roller bearing milled tooth bit with extended jets, (2) 437X—a soft formation, sealed friction bearing insert bit, with gauge protection and chisel-shaped teeth. 

Sealed Friction Bearing (Journal Bearing). The Journal hearing, developed to match the life of carbide cutting structures, does not contain rollers hut contains only a solid journal pin mated to the inside surface of the cone. This Journal becomes the primary load carrying element for the cone loads. 

In Figure 2, the height of the specimens is plotted against the load exerted on the piston, P, in Mp, at various temperatures. To give a clearer picture, only the measurements made at one temperature (156° C.) are shown. Similarly, the hysteresis curves produced by seal friction are given only once. The mean values are given for all other temperatures. 

N650 High modulus, high hardness, low die swell, smooth extrusion Tire innerliners, carcass, belt, sidewall compounds, seals, friction compounds, sheeting... 

It is clear that all the end effects are not caused by the seal friction and cylinder end surfaces alone. A 40mm long rotor with a 5mm annular gap has an end effect equivalent length of 58mm. Approximately half of this can be explained as due to the radial surfaces at the sides of the rotor and the likely losses in the thick fluid films on the seal faces. The remaining end effects are probably due to three dimensional flow effects which may be unique to the test rig or may be generally applicable. 

OGATA, M., KITADA, F., FUJII, T., and SHIMOTSUMA, Y. Studies of lip-type oil seal - friction and lubrication conditions within the sealing zone, JSLE. Intern. Edit., 1983, No.4. 135-142. 

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