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Porous metal bearings
233
BOOK REVIEWS
Air-blown W.S.
sintered-metal
turner bars as an aid to web transport.
Deason, pp. 410-416, 5 figs., I table, I ref. Details of the design of an air-blown porous-metal
turner bar which virtually
eliminates friction effects as the web passes over the bar are given. limitations of such bars are discussed. Practical
working
conditions
for sintered
Advantages
and
bearings.
M. Eudier and R. Margerand, pp. 417-425, 9 figs., 4 refs. A new type of porous bearing is described in which load capacity
and PV factor
can be increased due to the elimination of emulsification of the oil film by the introduction of an internal layer of very fine powder. The theory and practical implications are discussed. Porous metal bearings. V. T. Morgan, pp. 426-451, The paper indicates
14 figs., 3 tables, 8 refs. a technique for predicting
the performance
of a known
bearing design and once this is achieved, the optimum design follows from a systematic assessment of the effect of changes to the many interdependent variables involved. Most factors that determine the performance characteristics of porous-metal bearings are sensitive to temperature and the method proposed commences with techniques for determining the temperature rise and hence the running temperature of the bearing. The temperature rise is obtained from the power loss at the bearing and the heat dissipation of the assembly. Guidance curves are given for oil viscosity and clearance, which can be used as an iterative design process that converges rapidly towards the required solution. Having predicted the running temperature, methods are given of predicting the life of the bearing according to the quality and quantity of the oil at that temperature. The effect of copper on the properties of lubricants. B. T. Fowler, pp. 452-461, 3 figs,. z tables, IO refs. The effect of copper on the properties of various lubricants
has been examined
in relation to the case of self-lubricating bearings. The various oxidation mechanisms involved are considered together with specific examples of the part which additives may play in the reduction of deposit formation, inhibition of oxidation and prevention of copper corrosion. Consideration OYZ the theory of friction: friction without wear. M. Eudier and H. Youssef, pp. 462-470, 6 figs., I table, 7 refs. A new concept of friction in relation to wear based on the fact that certain intermetallic compounds are unlikely to stick on common metals is presented. The elastic vibrations produced in metals added to intermetallic compounds produce the necessary sticking followed by shearing to cause friction. It is shown theoretically that a condition of friction without wear can be produced. Practical results are given where the lives of clutches have been prolonged by factors of up to IOO ; similar improvements are quoted for brakes. New phenomena are explained which limit the life of friction materials even if wear is negligible. Wear of rock-cutting H. J. Osburn,
tools.
pp. 471-502,
4 figs., 45 refs.
BOOK REVIEWS
Air-blown W.S.
sintered-metal
turner bars as an aid to web transport.
Deason, pp. 410-416, 5 figs., I table, I ref. Details of the design of an air-blown porous-metal
turner bar which virtually
eliminates friction effects as the web passes over the bar are given. limitations of such bars are discussed. Practical
working
conditions
for sintered
Advantages
and
bearings.
M. Eudier and R. Margerand, pp. 417-425, 9 figs., 4 refs. A new type of porous bearing is described in which load capacity
and PV factor
can be increased due to the elimination of emulsification of the oil film by the introduction of an internal layer of very fine powder. The theory and practical implications are discussed. Porous metal bearings. V. T. Morgan, pp. 426-451, The paper indicates
14 figs., 3 tables, 8 refs. a technique for predicting
the performance
of a known
bearing design and once this is achieved, the optimum design follows from a systematic assessment of the effect of changes to the many interdependent variables involved. Most factors that determine the performance characteristics of porous-metal bearings are sensitive to temperature and the method proposed commences with techniques for determining the temperature rise and hence the running temperature of the bearing. The temperature rise is obtained from the power loss at the bearing and the heat dissipation of the assembly. Guidance curves are given for oil viscosity and clearance, which can be used as an iterative design process that converges rapidly towards the required solution. Having predicted the running temperature, methods are given of predicting the life of the bearing according to the quality and quantity of the oil at that temperature. The effect of copper on the properties of lubricants. B. T. Fowler, pp. 452-461, 3 figs,. z tables, IO refs. The effect of copper on the properties of various lubricants
has been examined
in relation to the case of self-lubricating bearings. The various oxidation mechanisms involved are considered together with specific examples of the part which additives may play in the reduction of deposit formation, inhibition of oxidation and prevention of copper corrosion. Consideration OYZ the theory of friction: friction without wear. M. Eudier and H. Youssef, pp. 462-470, 6 figs., I table, 7 refs. A new concept of friction in relation to wear based on the fact that certain intermetallic compounds are unlikely to stick on common metals is presented. The elastic vibrations produced in metals added to intermetallic compounds produce the necessary sticking followed by shearing to cause friction. It is shown theoretically that a condition of friction without wear can be produced. Practical results are given where the lives of clutches have been prolonged by factors of up to IOO ; similar improvements are quoted for brakes. New phenomena are explained which limit the life of friction materials even if wear is negligible. Wear of rock-cutting H. J. Osburn,
tools.
pp. 471-502,
4 figs., 45 refs.