. Electric railways, theoretically and practically treated . f = weight of car ^ and T, = weights of front and rear = distance between points of sup-port of ^ = distance of center of gravity ofcar body above points of ; = height of point of support of carbody above the and c^ = height of center of gravity of truckabove the = wheel base of each and /„ = vertical pressures between carbody and truck at front and rearpoints of support,/^i and //o = reactions on the trucks resultingfrom the application to the carbody of the retarding
. Electric railways, theoretically and practically treated . f = weight of car ^ and T, = weights of front and rear = distance between points of sup-port of ^ = distance of center of gravity ofcar body above points of ; = height of point of support of carbody above the and c^ = height of center of gravity of truckabove the = wheel base of each and /„ = vertical pressures between carbody and truck at front and rearpoints of support,/^i and //o = reactions on the trucks resultingfrom the application to the carbody of the retarding forces //j and/u as indicated in Fig. \, 7£„, 7(!3 and 7C^ = vertical pressures between wheelsand track taken in numerical or-der from front to ^i, F^, F^ and F^ = horizontal retarding forces (offriction) applied at points of con-tact between wheels and track,taken in numerical order fromfront to rear. 2l6 ELECTRIC RAILWAYS. The wheels on each axle are rigidly connected, and beingsimilar figures of revolution and rotating around their com-. mon axis may be treated as one, and are below referred to in the singular number. BRAKES AND BRAKING. 217 The forces exerting turning moments around the pointof contact of the rear wheel of the front truck are the fol-lowing five: Wj, T^, h^, t^ and the resistance offered bythe mass of the truck to retardation, which is the force T — a exerted horizontally at the center of gravity of the gtruck. The moments of these forces around the point in ques-tion are: „ r , , r . T. ac. u\ r, 2, -, //, A, A -, and —^ , 2 2 g and as the algebraic sum of these moments must equalzero, we may write : w-,r Jub — = o, or, T. t T,ac, a/i = - + - + -— + —.... (3)22 gr r ^^^ and similarly for the rear wheel of the front truck: or, nu r !— + ///;_-!_ + .-1 ^ = o, 2 2 if w^ = Zi _|_ ^1 _ ^i^i _ ^22 ^ r r The wheels of the rear truck treated in a similar mannergive the equations : 2 2 g r r T„ t„ 77, a r, Ju b a/4 = —- -f-
Size: 1130px × 2211px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyorkvannostrand
