Axle lubricants

The severity of different lubricant applications covers a wide shear stability range. Figure 5.8 shows that engine oils are the mildest application, followed by automatic transmission fluids, hydraulic fluids and rear axle lubricants [63]. Thus, matching shear stability requirements of the application with the selection of VI improver is a key formulation consideration. 

Axle additive packs typically contain 6-8 components again a typical axle lubricant additive pack may contain many of the same components seen in automatic or manual transmission packs. The key differences lies in the need for an extreme pressure component, for which sulphurized isobutylene (SIB), polysulphides or xanthates are commonly used. 

The axle lubricant should be suited to the type of metallurgy of the components as these vary depending on the axle design and the manufacturer because ... 

The surface finish of the axle also has a major impact on the type of axle lubricant that is needed to protect it. The art of the formulator is to balance the level and type of extreme pressure components to ensure adequate initial protection and to also ensure longevity. Extreme pressure components are invariably oxidatively unstable to their high surface activity consequently axle lubricants generally have the poorest oxidative stability of all driveline fluids. A typical axle lubricant set of components is given in Table 10.4. 

Despite its demand for special lubrication, this gear type is in widespread use in industrial and automotive applications. It is used extensively in rear axles of automobiles having rear-wheel drives and is increasingly being used in industrial machinery. 

In this microcalorimeter, the heat sink is not a massive metal block but is divided into several parts which are mobile with respect to each other. Each thermoelectric element (E) and a cell guide (D) are affixed to a fluxmeter holder (C). The holder (C) is mobile with respect to a massive arm (B) which, in turn, rotates around a vertical axle (A). All parts of the heat sink are made of brass. Surfaces in contact are lubricated by silicone grease. Four thermoelectric elements (E) are mounted in this fashion. They enclose two parallelepipedic calorimetric cells, which can be made of glass (cells for the spectrography of liquids are particularly convenient) or of metal (in this case, the electrical insulation is provided by a very thin sheet of mica). The thermoelectric elements surrounding both cells are connected differentially, the Petit microcalorimeter being thus a twin differential calorimeter. 

Wagons fitted with (i) grease lubricated axle boxes (ii) end falling doors and (iii) doors on the floor (hopper type) should not be used for the conveyance of military explosives. 

Lubrication is probably almost as old as intelligent man. Dowson has described early evidence of lubricants in potters wheels, on chariot axles, on sledges, and between stone blocks in the construction of buildings. All of these are from the Sumerian and Egyptian civilisations, between 5000 and 3500 years ago. 

In fact it seems very unlikely that some of man s early machines would have worked at all without lubricants. One of the fastest ways to produce wood dust ("saw-dust") is to operate a wooden bearing without a lubricant. A very effective way to soften and weld metals is to operate a metallic bearing without a lubricant. Without lubricants the early geniuses who invented potter s wheels or chariot axles would have generated such rapid wear or seizure that they would probably have given up and gone back to some useful activity like hunting. 

This was also a period of great interest in lubrication associated with the needs of the machinery of the Industrial Revolution. Dowson mentions several patents for lubricant compositions of considerable complexity which were granted between 1800 and 1850. Nevertheless the next references to the use of molybdenite as a lubricant are by gold miners in the Colorado gold rush of 1858-62, who are said to have used it to lubricate the axles of their wagons. This can hardly be considered a new development, since it was probably only a repetition of use in primitive times. 

API GL-4. Lubricants intended for axles with spiral bevel gears operating under moderate to severe conditions of speed and load or axles with hypoid gears operating under moderate speeds and loads. These oils may be used in selected manual transmissions and transaxle applications, where API MT-1 lubricants are unsuitable. 

API GL-2 Lubricants intended for automotive worm gear axles operating under such conditions of load, temperature and sliding velocity that lubricants satisfying API GL-1 service will not suffice. Products suited for this type of service contain anti-wear additives or film-strength improvers specifically designed to protect worm gears. 

Caution The lubrication oil will flow out when separate the electric clutch housing from the front axle flange. It should use the container to hold it. 

Type T1 or TA scheduled every 3 months including an inspection and lubrication, including a check of (at a minimum) the lights, tires, brakes, coupling devices, safety equipment, and any other systems (refrigeration unit, sliding axles, etc.). 

Chariots found in Egyptian tombs dated to more than five thousand years ago have traces of animal fat, used as a lubricant, on the axle-bearing surfaces of their wheels. 

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