Mechanics of engineeringComprising statics and dynamics of solids: and the mechanics of the materials of constructions, or strength and elasticity of beams, columns, arches, shafts, etc . 158 MECHANICS OF ENGINEERING. 60 threads to the inch, speed 130 picks to the minute, wasfound to be 16 , , \ to each loom (p. 335). 151. Dynamometers of Absorption.—These are so namedsince they furnish in themselves the resistance (friction or aweight) in the overcoming (or raising) of which the power isexpended or absorbed. Of these the Prony Friction Brakeis the most common, and is used for mea
Mechanics of engineeringComprising statics and dynamics of solids: and the mechanics of the materials of constructions, or strength and elasticity of beams, columns, arches, shafts, etc . 158 MECHANICS OF ENGINEERING. 60 threads to the inch, speed 130 picks to the minute, wasfound to be 16 , , \ to each loom (p. 335). 151. Dynamometers of Absorption.—These are so namedsince they furnish in themselves the resistance (friction or aweight) in the overcoming (or raising) of which the power isexpended or absorbed. Of these the Prony Friction Brakeis the most common, and is used for measuring the powerdeveloped by a given motor (, a steam-engine or turbine)not absorbed in the friction of the motor itself. Fig. 163. Fig. 163. shows one fitted to a vertical pulley driven by the motor. Bytightening the bolt B, the velocity <v of pulley-rim may bemade constant at any desired value (within certain limits) bythe consequent friction, v is measured by a counting appara-tus, while the friction (or tangential components of action be-tween pulley and brake), = F, becomes known by noting theweight G which must be placed in the scale-pan to balance thearm between the checks ; then Fa=Gb, (1) for the equilibrium of the brake (supposing the weight ofbrake and scale-pan previously balanced on C) and the workdone per unit of time, or power, is Z = Fv. (2) A dash-pot is frequently connected with the arm to preventsudden oscillations. In case the pulley is horizontal, a bell-crank lever is added between the arm and the scale-pan, andthen eq. (1) will contain two additional lever-arms. WORK, ENERGY, AND POWER 159 < — l— 1 Po R P2 P3 P* P5|^ Pe 152. The Indicator, used with steam and other fluid engines,Is
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectenginee, bookyear1888
