Nature and Location of the Transfer Source

There are two fundamentally different ways in which the reservoir of transfer lubricant can be located. It can be a part of, or the whole of, one of the normal load-bearing machine components, and this has been variously described as direct, primary, or two-body transfer lubrication. Alternatively it can be a separate auxiliary component present only to provide a lubrication reservoir, whose sole function is to transfer lubricant to one of the other machine components. This has been described as indirect, secondary, or three-body transfer lubrication. In the Russian literature the latter is called Rotaprint Lubrication by analogy with the use of a separate inking roller to transfer ink to the cylinder in a rotary printing press ° ° ° . 

1 Direct Transfer Lubrication Direct transfer lubrication has theoretical advantages in reducing the complexity of the overall design and in shortening the path from the reservoir to the lubricated bearing surface. However, a major limitation is that the lubricant reservoir must withstand the same load, speed, temperature and other conditions as are required by the function, load path, power, etc. of the machine design. This imposes severe constraints on the composition and method of incorporation of the reservoir material. 

Where a load-bearing machine component is manufactured completely from the composite, the problem of material selection is the conventional one of relating material properties to the design requirements. It is sometimes possible to use the 

Where neither a load-carrying component nor a less critical component can be completely manufactured from the reservoir material, a useful alternative is to bond, rivet or press composite onto the surface of a metal component, or to incorporate inserts of the composite in a machine component. Many applications of this technique have been developed, and a few examples will serve to illustrate it. 

The test engine ran for 6 hours at 2500 - 3000 rpm, and failed due to cam wear. This compared with 10 seconds before seizure for a completely unlubricated engine, and 30 minutes for an engine with only a bonded coating. 

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