90 



Indiana University Studies 



pulley in inches by the width of the belt in inches and this product 

 by the number of revolutions per minute and divide this number 

 by 2,860 for single belts and 1,720 for double belts. 



The following table, furnished from the catalog of one of the 

 manufacturers of shafting, shows the horse-power that can be 

 transmitted by various sizes of shafting running at various 

 speeds. 



HORSE-POWER OF SHAFTING 



Diameter of Shaft 

 (Inches) 



Revolutions per Minute 



100 



125 



150 



175 



200 



250 



300 



J- 16 

 1 15. 

 ^ 16 



•^16 



2H 



O 1_5 

 ^16 

 Q _3_ 

 'J 16 



^16 



Q 11 

 'J 16 

 Q 15 

 <J 16 



^16 

 415 

 ^16 



16 

 C 15 

 ^16 



2.4 

 4.3 

 6.7 



10. 



14.3 



19.5 



26. 



33.8 



43. 



53.6 



65.9 



80. 

 113. 

 156. 

 208. 

 270. 



3.1 

 5.3 

 8.4 

 12.5 

 17.8 

 24.4 

 32.5 

 42.2 

 53.6 

 67. 

 82.4 



100. 



142. 



195. 



260. 



337. 



3.7 

 6.4 



10. 



15. 



21. 



29. 



39. 



51. 



64. 



79. 



98. 

 120. 

 171. 

 234. 

 312. 

 405. 



4.3 

 7.4 



11.7 



17. 



25. 



34. 



43. 



59. 



78. 



94. 

 115. 

 140. 

 199. 

 273. 

 364. 

 472. 



4.9 

 8.5 



13. 



20. 



28. 



39. 



52. 



67. 



86. 



107. . 



121. 



160. 



228. 



312. 



416. 



540. 



6.1 



10. 



17. 



25. 



35. 



49. 



65. 



84. 

 107. 

 134. 

 165. 

 200. 

 285. 

 391. 

 520. 

 675. 



7.3 



13. 



20. 



30. 



43. 



58. 



78. 

 101. 

 129. 

 159. 

 196. 

 240. 

 342. 

 469. 

 624. 

 810. 



The principal cause of loss of power in shafting is improper 

 alignment and poor bearings; and much of this loss could be 

 avoided by proper care at the time of the installation. 



When we come to figure the cost of power transmission it is 

 readily seen that electrical transinission is far cheaper after it 

 is once installed. The best arrangement for power transmission 

 to the different machines of the mill or quarry is by electric 

 wiring, and the use of an alternating current motor at each ma- 

 chine. The mills are rapidly adopting this arrangement. 



The use of electric motors of all types in the mills and quarries 

 is increasing, and with the effort of central power plants to furnish 

 current to a number of plants in the district the use of alternating 



