Automatic gearbox

One of the most important properties of driveline fluids is their frictional performance in terms of both the level and durability. The fluid also has to be compatible with the components inside the transmission. Optimizing the frictional characteristics of a fluid for a particular application is absolutely critical to ensure trouble-free operation of the equipment, whether it be an automatic gearbox, synchronized manual gearbox or the wet brake system in a tractor. The problems that can be encountered are ... 

It may be noted that in this area the newly introduced nylon 46 has become of interest in auto automatic gears, gearboxes, engine differentials and the clutch area because of its exceptional ability (for a polyamide) to withstand severe mechanical and thermal loading. ... 

Fill the torque converter (or automatic clutch ) and thus convey power from the engine to the gearbox ... 

An electric motor of efficiency 0.92 and a manual 1-speed transmission have been used for all the simulations. The transmission often constitutes a significant loss factor, and losses in using 5-speed or automatic transmissions (Cuddy, 1998) are higher than for the 1-speed gearbox. Because the actual Lupo 3L has n electronically operated automatic transmission with higher efficiency than the corresponding manual transmission, the 1-speed model was selected in order to avoid a distorting impact on the simulation results. 

Typical manual transmission fluids additive packs contain 6-10 components, many being the same components used for modern automatic transmission fluids. The key differences are the treat levels of components, e.g. dispersants and friction modifiers, and the type and level of antiwear components. A typical manual gearbox standard operating temperature of 90 C is not as thermally challenging as that of a modern automatic transmission in excess of 120°C. This is usually reflected in the superior oxidative stability exhibited by modern automatic transmission fluids compared with manual transmission fluids. Table 10.3 shows the generic composition of a manual transmission fluid, with the component(s) that differ from an automatic transmission fluid highlighted. 

Automatic transmissions inflict a mileage penalty of about 10% compared to manual gearboxes. Continuously variable transmissions can provide better mileage. A stop-start engine that shuts down if a car is idling or... 

Power feed is provided from the knee gearbox, through the saddle, to the table lead-screw. Alternative hand feed is provided by a handwheel at each end of the table. Stops at the front of the table can be set to disengage the longitudinal feed automatically in each direction. 

This model overcomes the limitations presented and moves towards an approach of automated gearbox fault diagnosis systems. However, fault patterns need to be produced in order to compare these with operational data in order to predict automatically the actual condition of gearboxes. 

The second use case comes from a research project at an automotive company related to the development of an automatic transmission gearbox of a car. The automatic transmission is a complex mechatronic component that contains mechanical, hydraulic, electrical and software parts, that need to interoperate in order to achieve the overall functionality of the product. 

FIG. P-64 Automatic turning gear clutch type MS-8-T installed In gearbox between turning gear and pinion shaft. (Source MAAG Gear Company.)... 

---