Factors to Consider When Buying Oil Seals

As highlighted by the Oil Seal Manufacturers, improper selection, application, installation, and maintenance are the leading causes of external lubricant leakage in pumping systems, hydraulic presses, gearboxes, and storage tanks. However, these issues can be effectively addressed by gaining a better understanding of the various types of seal materials available, redefining the selection process, and consistently applying effective replacement and maintenance practices.

When selecting oil seals, several critical variables need attention. Designers and maintenance engineers should consider nine essential factors:

Shaft Speed

Determining the maximum shaft speed is influenced by various factors, including shaft finish, runout, concentricity of the housing bore and shaft, the type of fluid being sealed, and the material of the oil seal.

Temperature

It is crucial that the temperature range of the application does not exceed the elastomer temperature range of the oil seal.

Pressure

Most standard Oil Seals are designed for low-pressure conditions. If there is or may be additional internal pressure, it is necessary to manage that pressure effectively.

Shaft Hardness

A Rockwell hardness of 30 or higher on the shaft typically results in a longer seal life. If abrasive contaminants are present, aim for a hardness of RC 60.

Surface Treatment of the Shaft

Optimal surface preparation of the shaft significantly enhances sealing efficiency. The effectiveness of the seal is impacted by the direction of the finishing tool marks and the spiral guide. Polished or ground shafts yield the best results, with concentric finishing marks being ideal. If a spiral finish is necessary, it should direct towards the fluid flow during shaft rotation.

Concentricity

Inconsistencies between the center of the bore and the shaft lead to premature seal wear, predominantly on one side of the seal lip.

Shaft and Bore Tolerances

Close tolerances between shaft and bore lead to optimal seal performance. This is complemented by considerations of shaft eccentricity, end face movement, and vibration.

Runout

Minimizing runout is essential; its occurrence often results from bearing oscillation or shaft whipping. Adding misalignment can exacerbate the problem. It is a common misconception that installing a flexible coupling will remedy misalignment issues.

Lubrication

Seals function optimally when well-lubricated with oil of suitable viscosity that is compatible with the seal lip's elastomeric materials. Seal compatibility should account for potential concerns such as specific additives and certain synthetic lubricants, which are often neglected.

Additionally, our company offers various Agricultural Oil Seals. Should you have any inquiries, please feel free to contact us.