Shipbuilding and Shipping Record . haftsthat for a soUd shaft of diameter d 1 = — df16 • «here T is the twisting moment producing the stress /. Hence 16 T substituting the value of/obtained from this equation, = nd in equation (i) we get 6 32 T I wd*C (ii) July 19, 1917. SHIPBUILDING AND SHIPPING RECORD. 61 But the horse-power transmitted by the shaft at X revs, persets up a twisting moment T in the shaft such that 2 TT N T33,000 or T = 33,000 27r N The unit of twisting moment as obtained from this formula isthe lb. ft. This must be expressed in lb. ins. since modulus ofrigidi
Shipbuilding and Shipping Record . haftsthat for a soUd shaft of diameter d 1 = — df16 • «here T is the twisting moment producing the stress /. Hence 16 T substituting the value of/obtained from this equation, = nd in equation (i) we get 6 32 T I wd*C (ii) July 19, 1917. SHIPBUILDING AND SHIPPING RECORD. 61 But the horse-power transmitted by the shaft at X revs, persets up a twisting moment T in the shaft such that 2 TT N T33,000 or T = 33,000 27r N The unit of twisting moment as obtained from this formula isthe lb. ft. This must be expressed in lb. ins. since modulus ofrigidity and diameter of shaft are expressed in incli units. Hencewe have „ X 12 X „ . 2 TT N Substituting this value of T in equation (ii) we get1^32 X 33,000 X \2 X l\ TT- (i* C / N But for any given shaft I, d, and C are constants .•. B = constant X =c (iii) (iv) and a similar result ^\ould be arrive<l at if the foregoing investiga-tion had been made for a hollow shaft instead of for a soUd LJ zShi Fig. 2.—Diagram of Torsionmeter showing ArrangementoJ Flanges. Hence in either case, having determined the constant of the formula,the horse-power can be directly determined from a measurement ofthe angle of Uvist of a given length of the shaft. The instrument •used to measiu-e this angle of torsion is called atorsionmeter, and in most types on the market consists essentiallyof two collars clamped rigidly to the shaft at a given distance , as shown in Fig. 2. The second of these collars is providedvdih. a sleeve and a flange at the end of the sleeve, A\hich is thusbrought up close to the first collar, which carries a similar flange,the sleeve overlapping the first collar on which it is supported,usually on roller bearings, to keep it concentric ^vith the the collar and the sleeve are quite rigid, and it is thereforeobvious that when the shaft is twisted by the transmission of power,the flange on the sleeve -svill move re
Size: 2005px × 1246px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublisherlondon, bookyear191
