178 



HANDBOOK OF MECHANICAL DESIGN 



CHART FOR CALCULATING NEEDLE BEARINGS 



4,000 - 

 3,500 - 



3,000 - 



2,500 - 



2,200 - 

 2,000 - 



1,700 - 

 1,500 - 



1,300 - 

 1,200 



1,000 - 



si 900 



_j 



c? 800 



g 700- 

 I 600- 



D 

 O 



_l 



5f 500 



400 - 

 350 - 



300 - 

 250- 



200 - 



170 - 



150 - 



130 - 



^^. 



o 

 o 



T — r 



o o o 



o o o 



(T) '^ irt 



I I I I I I 



o 

 o 

 o 



o 

 o 

 in 





n^ Revolutions per Minu+e 



T — r 



o \ o o 



o \ o o 

 \ 



Safe load from needle bearings 



6,000 Nld 

 W= ', — 



ao5 



I 



\ 

 \ 



W= load on bearing in lb. 



N = number of rollers 



I = effecfive roller lengfh in in. 



d = roller diameter in in. 



n = r. p.m. 



_L 



< I.I 



0.1 \ 



-V 



02 

 , t 



0.25 03 



1 r 



i 2 i\ 5 3 7 i 



16 32 8 \32 16 32 4 



d, Diam.of Roller, vinches 



\ 

 \ 

 \ 

 \ 

 \ 

 \ 

 \ 

 \ 

 \ 



Pivof Scale V, 



/ 

 / 



Index lines show a needle bearing with 25 rollers 



g'*-i af 2,240 r.p.m. will safely carry a load of 



897 lb. 



Load figures are based on contacting surfaces 



hardened to Rockwell C-51 and accurate alignment 



y^.. 



/ .^" 



^-w-- 



eo 59 



58 57 56 55 54 53 52 

 Rockwell C Hardness Number 



51 50 



The curve shows that the bearing load Wof 

 8971b. ata bearing hardness of C-51, may be 

 Increased to 1.500 lb. at hardness of C-60 



l-Length of Cyli/ider I'n In. 



7 3 5 / i 



8 4 8/ 2 



_1 1 c^ 1 



Dimension 1 shown is the effective 

 length of the cylindrical portion 

 excluding rounded or projecting ends 



100 

 90 

 80 

 70 



60 

 50 



40 I 



o 



30^ 



E 



^)25. 



20 



- 17 



- 15 



- 12 



- 10 



