When deciding on the best type of seal for a particular application, it is best to consider all aspects of the environment and its purpose. If the application requires a spring- loaded seal, that does not eliminate either the rotary shaft seal or the mechanical seal. If the equipment is operating in extreme temperatures, including situations where the rapid movement of the equipment creates extreme heat, a mechanical seal will hold up better than an oil seal.

The pulley is kept from turning on the crankshaft by a key fitting into grooves on the crankshaft and pulley.

In recent research, MWCNTs and carbon black were mixed with the butadiene/natural rubber to form a hybrid composite which gives very strong filler links by partial replacement of carbon black based on the m₁:m₂:X (m₁—MWCNT; m₂—reduction amount of carbon black; X-varies from 1 to 6) [40,64]. An internal blending mixer and two-roll milling were used to formulate the composites. The synergistic effect plays a major role in improving the abrasion resistance property due to the partial replacement of carbon black by adding MWCNTs in different ratios. The optimal ratio value of MWCNTs is 5 (parts per hundred of rubber) and 27.5 (parts per hundred of rubber) for carbon black with better resistant to abrasion compared to the matrix material [64]. The vulcanized hybrid composite material reinforced with MWCNT/carbon black at the ratio of 1:1 shows better mechanical properties, curing characteristics, and thermal conductivity. This shows a better tyre thread with an improved endurance life, less curing time, and improved thermal conductivity [42,64]. Fig. 4.4 shows the SEM and TEM images of uncured and cured rubber and Figs. 4.5 and 4.6 show the application of rubber nanocomposites in a tyre application.