NKE 305806-2RSR 30x72x23.8 - Double Row Ball Track Roller

NKE 305806 2RSR 30x72x23.8 mm - Double Row Ball Track Roller

NKE 305806 2RSR is a double row ball track roller with a cylindrical bore, nominal dimensions of 30x72x23.8 mm and a crowned outer ring running surface. Manufactured under the NKE brand, it incorporates two rows of balls and rubber contact seals on both sides, identified by the suffix 2RSR. The roller is designed for applications involving rolling contact with suitably engineered tracks and guide surfaces.

Characteristics of NKE 305806 2RSR

The NKE 305806 2RSR is a yoke-type ball track roller with a cylindrical bore. Its outer ring serves as the rolling contact surface against a track or guide.

Unlike a conventional deep groove ball bearing installed in a housing, a track roller is designed to operate with its outer ring rolling directly against an external running surface.

The double row construction incorporates two rows of balls operating between the inner and outer rings.

Key characteristics:

• Manufacturer: NKE - industrial rolling bearing brand.

• Designation: 305806 2RSR - double row ball track roller with seals on both sides.

• Bore diameter: 30 mm - nominal shaft or axle mounting diameter.

• Outside diameter: 72 mm - nominal diameter of the outer ring running surface.

• Width: 23.8 mm - nominal axial width.

• Double row construction - two rows of rolling elements.

• Crowned outer ring - convex running surface designed for rolling contact with a track.

• 2RSR seals - rubber contact seals on both sides.

• Polyamide cage - maintains the spacing and guidance of the balls.

• Cylindrical bore - designed for mounting on a suitable shaft or axle.

Technical Specifications

The catalogue mass and EAN are associated with the NKE/Fersa product reference. Commercial catalogues may show different shipping weights or trade identifiers, so the exact delivered item should be identified using its manufacturer designation and packaging.

What Does NKE 305806 2RSR Mean?

305806 - Basic Track Roller Designation

The number 305806 identifies a specific track roller size and construction.

Unlike standard deep groove ball bearing designations, this number belongs to a track roller configuration with a specially shaped outer ring running surface.

The nominal dimensions of this product are 30x72x23.8 mm.

2RSR - Rubber Contact Seals on Both Sides

The suffix 2RSR identifies rubber contact seals fitted on both sides of the track roller.

These seals help reduce the entry of contaminants into the rolling element system and assist in retaining lubricant.

Compared with non-contact metal shields, contact seals provide a different level of contamination protection and may generate additional friction.

The 2RSR suffix does not identify the internal clearance class or bearing accuracy grade.

Construction and Operating Principle

Inner Ring

The inner ring has a cylindrical bore with a nominal diameter of 30 mm.

It provides the mounting interface between the track roller and a suitable shaft or axle.

Correct shaft dimensions and fits are essential for reliable operation.

Outer Ring

The outer ring has a nominal outside diameter of 72 mm and a crowned running surface.

This convex profile is designed to operate against an external track or guide surface.

A crowned outer ring can help reduce edge loading under certain alignment conditions.

However, the crowned profile does not eliminate the need for correct installation and alignment.

Double Row Ball Arrangement

The track roller incorporates two rows of balls.

The rolling elements transmit loads between the inner and outer rings while allowing the outer ring to rotate.

The primary operating load direction is radial.

Permissible axial loads and moments depend on the internal construction and the manufacturer's operating limits.

Polyamide Cage

The polyamide cage maintains the distribution of the balls and helps guide their movement.

The cage material must be considered when evaluating operating temperature, lubrication and other application conditions.

2RSR Contact Seals

Rubber contact seals are fitted on both sides of the roller.

They help protect the internal rolling contact surfaces against contamination and reduce lubricant loss.

The seals do not guarantee complete protection against pressurised water, severe abrasive contamination or aggressive operating environments.

NKE 305806 2RSR Compared with Other Variants

The 305806-2Z variant is listed in commercial catalogues with the same nominal dimensions of 30x72x23.8 mm.

However, the sealing arrangement differs from the 2RSR version.

2RSR vs 2Z

2RSR: Rubber contact seals on both sides, providing additional protection against contamination.

2Z: Metal shields on both sides, generally using a non-contact shielding arrangement.

Differences in sealing design can affect friction, contamination resistance, permissible operating speed and maintenance requirements.

NKE vs SKF Track Rollers

SKF 305806 C-2Z should not automatically be considered a direct replacement for NKE 305806-2RSR.

Even where nominal dimensions are identical, differences may exist in sealing arrangements, outer ring geometry, internal construction and operating parameters.

Typical Applications of Double Row Ball Track Rollers

Ball track rollers with cylindrical bores are used in mechanical systems where the outer ring rolls directly against a guide or track.

Typical application areas include:

• Industrial track systems.

• Linear guiding mechanisms.

• Material handling equipment.

• Conveyor and transport systems.

• Guide roller assemblies.

• Industrial automation mechanisms.

• Machinery incorporating rolling contact guidance.

These are general applications of this bearing type and do not represent confirmed OEM applications for the exact NKE 305806-2RSR designation.

Selection and Interchangeability

Before purchasing or replacing NKE 305806 2RSR, verify the requirements of the complete track roller assembly.

Important selection criteria include:

1. Full designation 305806-2RSR.

2. Manufacturer NKE.

3. Bore diameter of 30 mm.

4. Outside diameter of 72 mm.

5. Width of 23.8 mm.

6. Crowned outer ring running surface.

7. Double row ball construction.

8. 2RSR rubber contact seals.

9. Radial internal clearance.

10. Cage construction.

11. Applied radial loads and operating moments.

12. Lubrication, temperature and operating speed.

13. Track material and running surface geometry.

Identical nominal dimensions of 30x72x23.8 mm do not automatically establish full interchangeability.

The outer ring profile, internal bearing construction and sealing arrangement must also be verified.

Installation and Maintenance Recommendations

Before installation, inspect the shaft, mounting surfaces and running track for cleanliness and damage.

Apply mounting force only to the bearing ring being fitted with an interference fit.

Never transmit mounting forces through the balls, as this may damage the raceways and rolling elements.

Avoid direct impacts on the 2RSR contact seals.

During operation, monitor the condition of the running track, alignment and lubrication requirements.

Store unused track rollers in clean, dry conditions, preferably in their original protective packaging.

Alternative Designations and Search References

The product may be identified using the following formats:

• NKE 305806-2RSR

• 305806-2RSR NKE

• NKE 305806 2RSR

• 305806 2RSR NKE

• 3058062RSR NKE

• NKE 305806-2RSR 30x72x23.8 mm

• NKE double row ball track roller 305806 2RSR

These are alternative identification formats and not separate confirmed OEM part numbers.

FAQ - NKE 305806 2RSR

1. What are the dimensions of NKE 305806 2RSR?

The track roller has a 30 mm bore diameter, 72 mm outside diameter and 23.8 mm width. Its complete nominal dimensions are 30x72x23.8 mm.

2. Is NKE 305806 2RSR a standard deep groove ball bearing?

No. It is a double row ball track roller with a cylindrical bore and a crowned outer ring designed to roll against an external track.

3. What does 2RSR mean?

2RSR identifies rubber contact seals fitted on both sides of the track roller. These seals help protect the internal rolling elements against contamination.

4. Does NKE 305806 2RSR have two rows of balls?

Yes. It features a double row ball arrangement.

5. Are NKE 305806 2RSR and 305806 2Z identical?

No. The 2RSR version uses rubber contact seals, while the 2Z version uses metal shields. This difference can affect friction and protection against contaminants.

6. Is the outer ring running surface flat?

No. The outer ring has a crowned, convex running surface designed for rolling contact with a suitable track.

7. Can SKF 305806 C-2Z replace NKE 305806 2RSR?

Not without technical verification. Although the nominal dimensions may be similar, the sealing arrangement, outer ring profile and operating characteristics must be checked.

8. Does NKE 305806 2RSR require lubrication?

Like other rolling element bearings, it requires appropriate lubrication conditions. The maintenance and relubrication requirements should be determined from the manufacturer's instructions and the operating environment.

NKE 305806 2RSR - Key Technical Information

NKE 305806 2RSR is a double row ball track roller with a cylindrical bore and nominal dimensions of 30x72x23.8 mm. It features a crowned outer ring running surface, polyamide cage and rubber contact seals on both sides. The 2RSR designation identifies the sealing arrangement. Selection requires verification of track geometry, loads and operating conditions.

NKE track rollers are available through simmering.pl, a specialist supplier of rolling bearings, track rollers and industrial mechanical components.

With warehouse operations in Lublin, Poland, simmering.pl serves industrial maintenance departments, machine manufacturers and international B2B customers, with worldwide shipping options.