What is rubber oil seal?

When we talk about the shaft in the mechanical system which most have rotation which the shaft is supported by bearings. The bearing of the shaft is mounted to the housing to support the shaft weight, in which the housing is filled with lubricants Such as lubricant At the point where the shaft is out the oil seal is installed in that position. There is a duty to protect the liquid that is used to lubricate the outer shaft. In addition, oil seals are used to leak chemicals, water and many other fluids. Many types of oil seals are also designed to be able to prevent dust or dirt from entering into the oil or lubricant.

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Rubber Friction mechanism

In the design and development of rubber product such as tire , rubber seal , rubber automotive part , it is important to evaluate the contact load dependency of the friction coefficient. Mechanism of friction in rubber generates three different forms of friction: adhesion, deformation, and wear, which  adhesion force is the most influential component in rubber friction in dry conditions and low speed so that  adhesion friction is dominant for smooth contact at low speeds and dry conditions. Therefore increasing friction adhesion is possible by increasing the contact area of the product. Product samples that influence of the adhesion force is the industrial tire used in the warehouse where the floor is smooth and dry.

The hysteresis component of friction is caused by the bulk deformation of rubber material as it comes into contact with pavement asperities. Such deformation causes energy losses as rubber slides over the pavement surface. These energy losses are caused by the hysteretic.  In the case of contact between a rubber specimen and a rough hard surface , such as contact between tire and asphalt, the hysteresis component becomes dominate. 

The third major component of friction (cohesion losses) is caused by the wearing of rubber as it slides over the pavement surface. Pavement texture has an important role in the friction components—a recent study showed that higher pavement microtexture and macrotexture result in higher frictional properties. 

About Arrhenius theory

Who was Arrhenius ?. Svant August Arrhenius was born 19 February 1859 , Vik , Sweden and died 2 October 1927 , Stockholm , Sweden . He graduate from Stockholm university , Sweden . He work about chemical kinetic and physical chemistry.

Assumption for Arrhenius theory.

• The rate of each chemical step involved in the oxidation process(initiation , oxygen uptake,termination) must respond the same to changes in temperature.
• The oxidation proceeds uniformity throughout the material.

Arrhenius theory is originally derived from thermodynamics. When these assumption hold, the rate of oxidative aging, at the use temperature  T1, can be determined from the aging rate measured in the lab at a least temperature T2 . Arrhenius equation can write as follow

     k = A*exp(-Ea/RT)

When
k is rate
A is Pre Exponential factor
Ea is Activation Energy
R is gas constant
T is Temperature (Kelvin)

We  can  write another format of Arrhenius equation as follow

ln(k) = -(Ea/R)*(1/T) + ln(A)

Activation Energy is the minimum energy by which the colliding molecules of sample must have in order to bring about the degradation reaction. Lower the value of activation energy, higher will be the rate at which the degradation will proceed and vice-versa.

Testing for analysis with Arrhenius is

• Tensile , % Elongation , Modulus (ASTM D412)
• Tear Test (ASTM D624)