Mechanical Engineering-Tribology In Machine Design Episode 7 ppt

... design 1. 2 .1. Plain sliding bearings 1. 2.2. Rolling contact bearings 1. 2.3. Piston, piston rings and cylinder liners 1. 2.4. Cam and cam followers 1. 2.5. Friction drives 1. 2.6. Involute ... wear in higher kinematic pairs Introduction Loads acting on contact area 10 Tribology in machine design 1. 2.5. Friction drives Friction drives, which are being used increasi...

Ngày tải lên: 13/08/2014, 05:21

... 2 tan0 simplified Vabr =- - 71 H WL, Figure 2. 8 P E w3I2 refined Vabr =n2 ~2 ~3 12 L9 Ic 30 Tribology in machine design where k=h - 2BmR. If 1, is known, then In ... determined by examining the plasticity index, rl/. However, in the mixed lubrication regime in which A is in the range 1.0-3.0, where most machine sliding contacts or slid...

Ngày tải lên: 13/08/2014, 05:21

... defines the allowed ranges of certain parameters. In using this equation these parameters cannot be allowed to assume values for which the assumptions made in obtaining eqn (2.102) are invalid. ... Tribology in machine design equilibrium, are the basis of the theory of fluid-film lubrication or hydrodynamic lubrication. The solution of the indefinite integral (dp/dO)dO is gi...

Ngày tải lên: 13/08/2014, 05:21

... continues rapidly in a direction away from the arrowhead point of origin, increasing in width and length. It is then called spalling. Spalling occurs more often in rolling-element bearings ... so-called inclusion-origin failure. Inclu- 80 Tribology in machine design 3.7.3. Refinement for thermal bulging in the conjunction zone Thermal bulging relates to the fact that fri...

Ngày tải lên: 13/08/2014, 05:21

... lubrication and wear in lower kinematic pairs 1 05 the fact that when r>+ the machine will not sustain the load when the effort is removed. Thus, referring to the inclined plane, Fig. 4.9, ... corresponding to the maximum efficiency given above and the mechanical advantage is reduced in the ratio 4. 75 : 0.9 = 5. 23 : 1. In general, the following is approximately t...

Ngày tải lên: 13/08/2014, 05:21

... = 2 267 Nm kinetic energy developed in machine shaft = +lo2 = 44 .6 x 31.4~ = 2 267 Nm thus total energy supplied during the period of clutch slip =energy dissipated + kinetic ... =2 267 + 2 267 =4534Nm. 1 1 6 Tribology in machine design and Q =pA = R, sin oc hence, torque transmitted = fpAr,, (4.45) where f is the coefficient of friction...

Ngày tải lên: 13/08/2014, 05:21

... have from eqn (4.110) tab lZY sin O sin(b - O)dO -0. Again, expanding sin@ - O) and integrating 411,-sin4$ tanP= 1 - cos 4* 146 Tribology in machine design F =the maximum possible ... from the line of action of R, and the above equations become 156 Tribology in machine design ;T can be distinguished; free rolling, braking, accelerating, cornering or any co...

Ngày tải lên: 13/08/2014, 05:21

... 70.9 -83 .0 70.9-103 .8 27.7 6.57-20 .8 13 .84 14.7 - - - - - - - - - Density (kg/m3) 7 169-74 18 3405 3792 16 331 287 9 24 08 1771 -1910 2297-2 685 Hardness 217-269 87 8 7 9 2 86 -88 280 0 ... fluctuating loads on cylindrical bearing films is more difficult to analyse. Squeeze-film action is important in cushioning and maintaining a film in linkage bearings suc...

Ngày tải lên: 13/08/2014, 05:21

... established in the following areas: (i) Machine tools. Use of gas lubrication in grinding spindles allows attainment of high speeds with minimal heat generation. 196 Tribology in machine design ... parameters, including length, which is useful in design and in plotting experimental results. It will be used here in the remaining derivations and discussion of the prin...

Ngày tải lên: 13/08/2014, 05:21

... expressed in consistent units. 5.9. Modern Thin-wall bearings, defined as lined inserts which, when assembled into a developments in journal housing conform to that housing, are commonly used in ... where bearings have been designed with a reduced 236 Tribology in machine design trailing wheels of a vehicle, however, rotate in bearings assumed to be frictionless and t...

Ngày tải lên: 13/08/2014, 05:21

... use in high-temperature rolling-element bearing lubrication. Primary use of bonded films and composites containing solid film lubricants occurs in plain bearings and bushing in the aerospace industry. ... following expression may be used to determine the thermal correction factor for line contacts In eqn (6.28) the thermal loading factor, Tl, is defined as 260 Tribology in m...

Ngày tải lên: 13/08/2014, 05:21

... out. In most cases pitting is initiated in the vicinity of the pitch line. At the pitch point there is only pure rolling while above and below it there is an increasing amount of sliding aiong ... in machine design transmitting power in the range of 100-500 kW at a pitch line velocity not exceeding 15 nl s- '. The usual procedure is to determine both a thermal rating...

Ngày tải lên: 13/08/2014, 05:22

... further increase in velocity. There is, however, one important difference in the lubrication mechanism operating in plain journal bearings and in gears. In the case of the journal bearings, ... bearing, 7 Rolling contact bearing, 7, 248 Rolling friction, 235, 248 Rolling of tyre, 155 Rope drive, 134 Run -in, 11 Screw jack, 105 Scuffing, 9, 1 1, 12, 278 Self-lubricating...

Ngày tải lên: 13/08/2014, 05:22

... of tribodesign 1 1 .1. Specific principles of tribodesign 4 1. 2. Tribological problems in machine design 6 1. 2 .1. Plain sliding bearings 6 1. 2.2. Rolling contact bearings 7 1. 2.3. ... Conditions in the cylinder of an internal combustion engine can be 10 Tribology in machine design 1. 2.5. Friction drives Friction drives, which are being u...

Ngày tải lên: 13/08/2014, 17:20

... be obtained by substituting r for x and 17 1 = U 2 =0 in eqn (4.2a) 172 Tribology in machine design 4.15.11. Lubric ati on of seals The initial assumptions used in analyses ... the fluctuating loads on cylindrical bearing films is more difficult to analyse. Squeeze-film action is important in cushioning and maintaining a film in linkage bea...

Ngày tải lên: 13/08/2014, 17:20