FKM High-Temperature Rotary Shaft Oil Seals

FKM high-temperature rotary shaft oil seals are designed to retain lubricants and reduce leakage around rotating shafts in industrial machinery. Made with fluoroelastomer (FKM) sealing elements, they are commonly selected for applications involving elevated temperatures, lubricating oils and operating conditions where conventional elastomer seals may have limited service life.

These radial shaft seals are used in gearboxes, pumps, motors, industrial drives and other rotating equipment. Different lip designs, metal case constructions and spring configurations are available to suit specific shaft and housing arrangements.

FKM Material & Sealing Performance

FKM is a family of fluoroelastomer materials known for resistance to many petroleum-based oils, fuels and industrial lubricants, as well as good heat and aging resistance.

Compared with conventional NBR compounds, suitable FKM formulations can provide improved performance in elevated-temperature environments. However, chemical compatibility and temperature capability depend on the specific compound.

FKM is not universally resistant to all chemicals. Certain amines, ketones and other aggressive media may require alternative elastomer grades or specialized sealing materials.

Oil Seal Types & Constructions

Single Lip Oil Seals

Single lip designs use a primary sealing lip to retain oil or grease around the rotating shaft. They are commonly used in lubricated industrial equipment where a separate dust-exclusion lip is not required.

Double Lip Oil Seals

Double lip designs typically combine a primary sealing lip with an additional auxiliary lip. The auxiliary lip can help reduce the entry of dust and contaminants, depending on the seal design and installation.

The auxiliary lip is not necessarily intended to retain fluid pressure or provide a second pressure-rated seal.

Spring-Loaded Oil Seals

Many rotary shaft oil seals incorporate a garter spring to maintain contact between the sealing lip and the shaft. The spring helps compensate for changes in lip contact conditions during service.

Metal-Cased & Rubber-Covered Oil Seals

Metal-cased designs use a rigid outer metal case for installation into the housing bore. Rubber-covered designs provide an elastomeric outer surface that can help seal against suitable housing bore surfaces.

The correct construction depends on the equipment design, housing condition and installation requirements.

Industrial Applications

FKM rotary shaft oil seals are commonly used in:

• Industrial gearboxes and speed reducers

• Electric motors and drive systems

• Pumps and rotating machinery

• Lubricated shafts and bearing housings

• Automotive and industrial transmission components

• Industrial maintenance and replacement applications

Dimensions & Shaft Compatibility

Rotary shaft oil seals are generally specified by three main dimensions: shaft diameter, housing bore diameter and seal width.

The common dimensional format is:

Inside Diameter (ID) × Outside Diameter (OD) × Width (W)

Correct sizing is essential for proper installation and sealing performance. Shaft surface finish, hardness, runout, installation alignment and