Metal inserts must be carefully prepared in operations involving cleaning and roughening surfaces (grit-blasting or phosphatizing), stamping out parts, application of primer (usually by dipping), and curing of the primer (often by baking for a short time at moderate temperature).³ Primer curing minimizes the possibility of wiping primer off portions of the insert by stock flow during molding. The treated metal inserts must be used within a relatively short time (usually a day or less), so that functionality necessary for bonding is not lost by reaction with moisture in the air. Freshness of the primer surface is particularly important for peroxide-cured and base-resistant fluoroelastomer compounds. Compound formulation should be adjusted to attain good adhesion.

Carboxylate Nitrile 

Heat and attrition are generated by the parts moving against each other. The sealing function can only be ensured if an intentional defined leakage of oil is able to exit for seal lubrication, preventing seal wear and possible failure, while a tight static seal between shaft and sealing lip must be assured when the shaft is stationary.

Replacing gaskets and oil seals

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.

Refit the rocker or cam cover, aligning its fixing holes with those on the head. Check that the gasket edge aligns with the cover flange all round, and is not distorted. If necessary, adjust it gently with tweezers or long-nosed pliers. Tighten bolts evenly to just compress the gasket.

There are many different materials used to manufacture oil seals.

Table 8 shows the housing design checklist.

4.  SHAFT SPEED: As different shafts move at different speeds you need to consider the runout, the housing bore, and oil type being sealed. Ensure you select a seal that will not suffer from abrasions or spiralling.