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ENGINEERING FOR AIRFRAME CONTROL AND BALL BEARING ROD ENDS

ENGINEERING FOR AIRFRAME CONTROL AND BALL BEARING ROD ENDS
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ENGINEERING FOR AIRFRAME CONTROL AND BALL BEARING ROD ENDS - 3

tightness and/or roughness when the bearing isspun in a misaligned position.A study of the internal design will show that in pure misalignment (not accompanied by rotation) the balls do not roll but skid across the ball raceway due to their wedging action.Any inspectors insistence that bearings be loosely fitted to insure ease of misalignment would be unjustified and might cause flutter because of sloppy controls.A reasonable amount of tightness in self-aligning bearings (not excess binding) will insure the desired rigidity in the control linkage system. Please adhere to instructions on...

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ENGINEERING FOR AIRFRAME CONTROL AND BALL BEARING ROD ENDS - 4

∑ K it is possible to calculate one equivalent load whichwould give the same number of cycles average life as the various loads.No one load may be greater than the limit load rating of the bearing.The equivalent load may be calculated from the formula:P = [ > AIRCRAFT CONTROLBEARINGS Taking the 1208 lb.Equivalent load (above) in anapplication where the heaviest of three radial loads is 2000 lbs.,we can proceed through the KP and KP-A Series locating the smallest acceptable bearing as follows.If there is no oscillatory life requirement stated andwe are setting up an overhaul period acording...

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ENGINEERING FOR AIRFRAME CONTROL AND BALL BEARING ROD ENDS - 5

AIRCRAFT CONTROLBEARINGS LIFE FACTOR CHART 1.0 -.9 -.8 -.7 -.6 -.5 -.4 -.3 - .2 - > Life Factor 10,000100,000 1,000,000 > Average Life Complete 90װ Oscillatory Cycles 5 size="-1">

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ENGINEERING FOR AIRFRAME CONTROL AND BALL BEARING ROD ENDS - 6

We want to figure the Equivalent Thrust Load andthe safety factor on a KP10 (Single Row) bearing in an application where the radial load imposed is 4000 lbs., the thrust load is 200 lbs.,and the overturning moment load is 425 in.lbs. Substituting in the formula:Equivalent Thrust Load= (.44 X 4000 lbs.) + 200 lbs.+ (4.09 X 425 in.lbs.) = 3698 lbs. Safety Factor =(6200 lbs./3698 lbs.) X 1.68 > AIRCRAFT CONTROLBEARINGS When Radial Load,Thrust Load and Moment Loadare encountered in combination (all three or any two) on a single bearing mounting,we obtain an equivalent thrust limit load and...

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ENGINEERING FOR AIRFRAME CONTROL AND BALL BEARING ROD ENDS - 8

Once the bearings are ordered,the designer mustinsure that the mating components are consistent with his requirements.Particularly,he must hold housing and shaft fits within specified limits and maintain close control on roundness of these two dimensions.Interference fits directly affect the internal clearance in ball bearings,as much as 50% to 80% of the interference translates into reduced radial internal clearance,depending on the size of the bearing involved.Paralleling this situation,unequal heating of the inner and outer rings can have the same effect.Frequently,both conditions exist...

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ENGINEERING FOR AIRFRAME CONTROL AND BALL BEARING ROD ENDS - 10

Standard Radial Reduced Radial Standard Radial Reduced Radial Play Play Play Play MS Fafnir MIL-G-81322 MIL-G-81322 MIL-G-23827 MIL-G-23827 Series Series Grease Grease Grease Grease MSFAFNIR MSFAFNIR MSFAFNIRMSFAFNIR Suffix Suffix Suffix Prefix/Suffix Suffix Suffix Suffix Prefix/Suffix 27640KP27641KP-A NONE FS464 R M/FS464 GFS428 RGM/FS428 27643DSP 27645KSP 27644DPP27646B500DD27648KP-BS NONE FS464 N⁄AN⁄A G FS428 N⁄A N⁄A 27649AW-AK 21428MB500DD 27647DW NONE FS464 R M/FS464 L M/FS464 RL M/FS428 27642KP-B(1) S > (1) FS464 G SG > (1) FS428 (1) MKP-B Series are used for MS27642 bearings with an...

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