Dynamometers and the Measurement of Power: A Treatise on the Construction and Application of Dynamometers |
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Common terms and phrases
adjusted amount angle apparatus ascertained attached average axis back gears Baldwin Locomotive bolted brake C₁ caisson cast-iron cent centrifugal force coefficient of discharge coefficient of friction connected constant countershaft current-meter cylinder depth determined diameter disk dynamometer employed engine equal experiments feet per minute float foot-pounds formula friction-brake gauge given speed grooves horizontal horse-power hydraulic motor inches knife-edges lathe lever lever-arm load loose pulleys lubrication machine measured metal motion nozzle number of revolutions obtained pass pipe plate plunger pointer-hand position pounds power required pressure Prof quantity of water radius required to drive resistance revolutions per minute revolve rubbing surface Samuel Webber scale scale-beam scale-plate screw shown in Fig side sliding speed of rotation spindle spur-gear strap stream tank tension thickness tion transmitted tube turbine varying vertical weight weir wheel width of belt William Sellers wrought-iron zero
Popular passages
Page 92 - The pulley on an engine shaft is 5 feet in diameter, and it makes 100 revolutions per minute. The motion is transmitted from this pulley to the main shaft by a belt running on a pulley, and the difference in tension between the tight and slack sides of the belt is 1 15 Ibs.
Page 7 - ... In the ordinary machine shop this loss will probably average from 40 to 50 per cent. No matter how well a long line of shafting may have been erected, it soon loses its alignment and the power necessary to rotate it is increased. In machine shops with a line of main shafting running down the center of a room, connected by short belts with innumerable counter-shafts on either side, often by more than one belt and, as frequently happens, also connected to one or more auxiliary shafts which drive...
Page 174 - ... obstruction to the slipping off of straws, leaves, or grass as the wheel revolves. The central hub is made tapering so that any object can slide off easily, and it extends over the joints at the ends of the axis, so as to enclose and protect them from floating substances. The axis runs in iridium bearings. The forward end of the frame which carries the wheel can be turned and secured in any position, so that the wheel can be horizontal, vertical, or at any desired angle. ' ' The electrical connection...
Page 64 - ... the bottom of the stationary half cell which it faces. The effectiveness of this combination to resist rotation will be seen to depend essentially on this quasiantagonistic virtual approach of the moving to the stationary half cells. The channel and the whole casing is filled with water, and the turbine is made to rotate as described. When the turbine is thus put in motion, the water contained in each of its half cells is urged outwards by centrifugal force; and in obeying this impulse it forces...
Page 67 - The casing will be provided with proper apertures, capable of being closed at will, to permit the egress of air and the ingress of water as the dock fills. The casing will thus be in a condition to receive the moment of rotation delivered by the screw, and to communicate it to the recording apparatus. If the "moment" to be recorded is regarded as a product of two factors, "force...
Page 189 - ... as shown. Connected with the scale is a brass screw passing through a socket, fastened to another shorter sliding piece, shown above, which can be clamped at any point on the frame, and the scale with hook moved in either direction by the milled head nut.
Page 62 - ... held stationary; the jets are alternately dashed forward from projections in the turbine against counter-projections in the interior of the casing, tending to impress forward rotation upon the casing, and are in turn dashed back from the projections in the casing against those in the turbine, tending to resist the turbine's rotation.
Page 61 - ... will vary with the speed of rotation, much in the same way as the resistance of the propeller itself does; and thus the work performed by the engine under trial will more closely resemble its natural work, though the same circumstance renders necessary an automatic method of recording the variations of the resistance (or of the weight that is in effect being lifted), which occurs during the trial.
Page 176 - A hollow cylinder of bronze, called the trunnion, fitting easily upon the rod, supports the frame of the Meter by a pivot on each side, and thus by the rod and pivots the Meter is free to move both horizontally and vertically, and so adjust itself to the direction of the current. The frame of the Meter is made of bronze, and is very solid and strong. The rudder has four light metal wings FRAME AND or vanes, -secured to a central rod, and is RUDDER. made to balance the weight of the wheel and give...
Page 55 - An ingenious form of valve operated by the slight angular motion of the dynamometer varies the supply of water, and consequently the pressure between the frictional surfaces, thus securing automatic regulation. Referring to Figs.