POWER TRANSMISSION ELEMENTS AND MECHANISMS 161 

 SHAFT DIAMETERS FOR TORSION AND BENDING 



15 ^ 

 16 



•IH 



0) lb 

 u 



.5^16 



O 7 



E-^ie 



D 

 II 



- 1.5 



3^-_ 



4,4- 



^16 



4^-- 



5,i 

 6,2 -^ 



16 



E-7 



D=J^ 



M-^ + T^ 



Example: Given f= 6,000 lb. persq.in- 

 Bending momen+ M= 100,000 in.-lb. 

 Torsional mornen+ T = 50,000 in.-lb. 



1 Determine equivalent bending mornen+ 

 Join 100 on horizontal A scale +o50on 

 vertical A 5cale. This length scaled off 

 on vertical A scale is the equivalent 

 bending moment= 111,000 in.-lb. 



2 Join 111,000 on B scale to 5,000 on^f 

 scale and extend line to read 4.6" 

 diam. on left scale 



Nofe: For ordinary power -transmission 

 shafting use 6,000 lb. per sq. in. for 

 fhe allowable working stress 



Bending Moment,in Thousands Inch- Pounds 



B 

 500,000 — 



400,000 ■ 

 300,000 - 



200,000 -^ 

 150,000 — 



20,000- 



15,000— 



-650 



— 600 



-550 



-500 



c 



-450 c 

 o 



-400 c 



ty 



E 

 o 



-350 .E 



■300 i 



D 

 > 



cr 



-250 "^ 



E 

 -200 S 



-rr 



500 



450 



I I I I I I I 

 400 



I I I I I 

 350 



ri m I I r 

 300 250 



I I I I I I I I 

 200 150 



