Cyclopedia of locomotive engineering, with examination questions and answers; a practical manual on the construction care and management of modern locomotives . 75^ LOCOMOTIVE ENGINEERING With the limited amount it is advisable to allow inraising or lowering the link block in reversing the mo-tion, we can without practical error consider the halfmovement of the link block g to be the same as that ofpoint F, and by limiting the angle of the swing of the ?— -~ i iX <*l .£~C i FIG. 334 link to a maximum of 45 °, we get the raise or depression of the radius bar and link block Og = -r, where O t
Cyclopedia of locomotive engineering, with examination questions and answers; a practical manual on the construction care and management of modern locomotives . 75^ LOCOMOTIVE ENGINEERING With the limited amount it is advisable to allow inraising or lowering the link block in reversing the mo-tion, we can without practical error consider the halfmovement of the link block g to be the same as that ofpoint F, and by limiting the angle of the swing of the ?— -~ i iX <*l .£~C i FIG. 334 link to a maximum of 45 °, we get the raise or depression of the radius bar and link block Og = -r, where O tan. a is the link fulcrum and d =half the angle of the swing of the link. -* ?C-S J ^ FIG. 335 The location of the link and eccentric rod connectingpoint K, Fig. 333, cannot be determined with any prac-ticable formula, but must, as already stated, be foundby plotting to meet the requirements of the different cut- WALSCHAERT VALVE GEAR 757 offs and corresponding crank positions. The same is alsothe case with determining the locus for the suspensionpoint P of the lifting link, and in these two locations liesthe principal success of the gear. 3/eos. FIG. 336 THE REAULEAUX AND ZEUNER DIAGRAMS. Figure 336 shows a combination of two diagrams,namely, those of Reauleaux and Zeuner, which coincideexactly as to the different valve movements, which maybe found as follows: The distance AB represents the travel of the valve as 758 LOCOMOTIVE ENGINEERING well as the stroke of the engine, though in different scales,which makes no difference when the cut-off is always ex-pressed in fractions or per cent of AB. The maximumcut-off is determined upon to be AR. Draw a perpendicu-lar line RC from AB until it cuts the arc ACB. Next de- |cide on a desired lead and, with that as a radius, draw anarc with A as a center. Draw a line from C tangent tothe lead circle around A, when the lap of the valve jis found to be equal to the perpendicular distance fromthe line CS to the center O of the diagram.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectlocomot, bookyear1916
