The Theory of machines |
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a₁ angular acceleration angular velocity assumed axis balance balls belt bevel gears body center of gravity centrifugal force chapter connecting rod corresponding crank angle crank effort crankpin crankshaft crosshead curve cylinder diameter direction distance draw equilibrium fixed flywheel forces acting frame friction ft.-pds given governor hence indicator diagrams inertia instant kinetic energy latter machine masses mean speed mechanism method moment of inertia move normal numbers of teeth opposite sense P₁ pair parallel phorograph piston pitch circles position pressure produce pulley R₁ r₂ radians per second radii radius reciprocating represent resultant revolutions per minute revolve rotation shaft shown in Fig shows sliding spindle spring spur gears steam engine stroke tangent threads tion torque train turning valve vector velocity ratio vertical virtual center w₁ weight wheel worm zero
Popular passages
Page 177 - ... operating lever as shown. In this case the pull in one side of the band assists the operating force. The force of friction necessary to balance a given torque is found for this kind of brake as it was for the block brake, and is equal to TI — T2, the difference between the tensions on the tight and slack sides of the band.
Page 202 - ... varied as to demand a complete work on it alone, and further because its design depends to some extent on the principles of thermodynamics and hydraulics with which this book does not deal. This valve always works in such a way as to control the amount of energy entering the engine in a given time and this is usually done in one of the following ways: (a) By shutting off a part of the working fluid so as to admit a smaller weight of it per second. This method is used in many water wheels and...
Page 79 - In the first place, when the wheels drive the pinions, the number of teeth in any one pinion should not be less than 8 ; but rather let there be 11 or 12 if it can be done conveniently. And in the particular form of teeth described in Art.
Page 180 - ... resistance to the sliding of one body upon another depended upon the normal pressure between the surfaces and not upon the areas in contact nor upon the velocity of slipping, and further that if F is the frictional resistance to slipping and N the pressure between the surfaces, then F = nN where n is the coefficient of friction and depends upon the nature of the surfaces in contact as well as the materials composing these surfaces. A discussion of this subject would be too lengthy to place here...
Page 115 - ... the collars at N and R, respectively. In addition to the gears already mentioned there is another, an idler gear L, which meshes with K and runs on a bearing behind the gear K. When it is desired to operate the car at maximum speed (third or high), the operator throws F into the position shown and pushes D to the left so that the clutch piece C engages with B, in which case P runs at the same speed as the engine shaft E. The second highest speed (second or intermediate) is obtained by slipping...
Page 231 - C = — y stant being a ft. pds. where co is the angular velocity of the disc in radians per second, and since co = -Rf.
Page 180 - ... place. Thus it would be quite impossible to walk were it not for the friction between one's feet and the earth, a train could not run were there no friction between the wheels and rails, and a belt would be of no use in transmitting power if there were no friction between the belt and pulley. Friction, therefore, acts as a resistance to motion and yet without it many motions would be impossible.
Page 298 - Let /& be the moment of inertia of the rod about its center of gravity...
Page xi - SYMBOLS USED The following are some of the symbols used in this book, with the meanings usually attached to them. w = weight in pounds. g = acceleration of gravity = 32.2 ft. per second per second. w m — mass = — g v = velocity in feet per second. n = revolutions per minute. ,. 2 7T71 o; = radians per second = „,. T = 3.1416.