NA 6909 JNS 45x68x40 mm

NA 6909 JNS 45x68x40 mm - Double Row Needle Roller Bearing with Inner Ring

NA 6909 JNS 45x68x40 mm is a double row radial needle roller bearing manufactured under the JNS brand. It belongs to the NA 69 dimensional series and features an inner ring, an outer ring, and two rows of needle rollers. The bearing has a 45 mm bore diameter, 68 mm outside diameter, and 40 mm width. Its open design includes a lubrication hole and is primarily intended to accommodate radial loads in compact bearing arrangements.

Technical Specifications of NA 6909 JNS

The dimensions and principal construction characteristics identify the JNS NA 6909 bearing. Dynamic load rating, static load rating, limiting speed, internal clearance, cage material, mass, and accuracy class should be verified against the manufacturer's technical documentation before being used in engineering calculations.

What Does NA 6909 JNS Mean?

The designation NA 6909 identifies the bearing's construction and dimensional series.

NA - Identifies a needle roller bearing series with an inner ring.

69 - Indicates the dimensional series of the bearing.

09 - Bore code corresponding to a nominal bore diameter of 45 mm.

JNS - Identifies the bearing brand.

The designation NA 6909 does not include an additional suffix specifying special internal clearance, a particular accuracy class, cage material, or integrated sealing arrangement.

These characteristics must not be assumed solely from the basic bearing designation.

Construction and Operating Principle

The JNS NA 6909 is a double row needle roller bearing designed to accommodate radial loads within a relatively small radial installation space.

Its construction consists of the following principal components:

• Outer ring: Provides the external raceway and fits into the bearing housing.

• Inner ring: Provides a hardened rolling surface for the needle rollers and allows installation on a suitable shaft.

• Needle rollers: Long cylindrical rolling elements with relatively small diameters, arranged in two rows.

• Rolling element guidance assembly: Maintains the positioning and guidance of the needle rollers. The exact cage construction and material require manufacturer confirmation.

• Lubrication hole: Provides a means of supplying lubricant to the bearing arrangement.

The double row configuration provides two rows of rolling contact between the inner and outer raceways.

Needle roller bearings offer a relatively small radial cross-section compared with many other rolling bearing types of similar bore diameter.

The NA 6909 JNS is primarily designed for radial loading. It should not be selected as the sole axial locating bearing without an appropriate analysis of the complete bearing arrangement.

Open Design and Lubrication

The JNS NA 6909 has an open construction without integrated contact seals.

This arrangement requires appropriate lubrication and protection against external contamination.

The lubrication hole can be incorporated into a suitable lubrication system, depending on the housing design and installation requirements.

Important operating considerations include:

• Correct lubricant selection for the operating conditions.

• Adequate lubricant supply to the rolling contacts.

• Protection against dust, moisture, and abrasive particles.

• Suitable shaft and housing fits.

• Control of operating temperature and radial loading.

The presence of a lubrication hole does not establish the type or quantity of lubricant supplied with the bearing.

Factory lubrication must be confirmed separately.

Alternative Designations and Search References

The same bearing designation may appear in different written formats:

• JNS NA 6909

• NA 6909 JNS

• JNS NA6909

• NA6909 JNS

The basic designation NA6909 is also used by other bearing manufacturers.

However, matching designations and nominal dimensions do not automatically establish complete technical interchangeability.

NA 6909 JNS Compared with Other Variants

A sealed NA6909 2RS bearing may have a different overall width from an open NA6909 bearing.

For example, certain sealed variants are listed with a width of 41 mm instead of 40 mm.

Consequently, the presence of the same basic designation does not guarantee identical installation dimensions.

Bearing Selection and Interchangeability

Before replacing or purchasing a JNS NA 6909 bearing, the following technical characteristics should be checked:

• Complete bearing designation and manufacturer.

• Nominal dimensions of 45x68x40 mm.

• Presence of an inner ring.

• Double row needle roller construction.

• Open or sealed bearing arrangement.

• Lubrication hole configuration.

• Required internal clearance and mounting fits.

• Dynamic and static load requirements.

• Operating speed and temperature.

• Lubrication method and contamination protection.

• Shaft, housing, and axial location requirements.

A bearing from another manufacturer with identical principal dimensions may differ in internal construction, load ratings, tolerances, cage design, or operating limitations.

Interchangeability must therefore be assessed using the complete technical specifications rather than dimensions alone.

Typical Applications of NA 6909 Needle Roller Bearings

The construction of the NA 6909 bearing is suitable for consideration in mechanical arrangements requiring radial load support with limited radial installation space.

Typical applications for this category of needle roller bearings include:

• Industrial machinery bearing arrangements.

• Rotating shafts and mechanical assemblies.

• Selected power transmission equipment.

• Compact mechanical drive systems.

• Industrial mechanisms with significant radial loading requirements.

These are general applications associated with the bearing type. They do not represent verified OEM applications of the specific JNS NA 6909 product.

Actual suitability depends on load conditions, speed, lubrication, shaft and housing geometry, and the complete machine design.

Installation and Maintenance Recommendations

Correct installation is essential for reliable bearing operation.

Cleanliness: Ensure that the shaft, housing, bearing seats, and surrounding components are clean before installation.

Mounting force: Apply installation force to the ring being fitted with an interference fit. Never transmit mounting force through the needle rollers.

Fits and alignment: Verify the shaft and housing tolerances and ensure correct alignment of the bearing arrangement.

Lubrication: Provide lubrication suitable for the expected load, speed, temperature, and operating environment.

Contamination protection: Because the bearing has an open design, the surrounding assembly should provide appropriate protection against contamination.

Storage: Keep the bearing in a dry, clean environment and retain its protective packaging until installation.

Frequently Asked Questions About NA 6909 JNS

What are the dimensions of the JNS NA 6909 bearing?

The bearing has a 45 mm bore diameter, 68 mm outside diameter, and 40 mm width. Its nominal dimensions are 45x68x40 mm.

Is NA 6909 JNS a needle roller bearing?

Yes. It is a double row radial needle roller bearing with an inner ring.

Does the JNS NA 6909 have seals?

No. The identified JNS NA 6909 version has an open construction without integrated seals.

Does the NA 6909 JNS have a lubrication hole?

Yes. The JNS model is identified as having a lubrication hole to support lubrication of the bearing arrangement.

What is the difference between NA 6909 and RNA 6909?

The NA 6909 has an inner ring, whereas the corresponding RNA series bearing does not. A bearing without an inner ring requires a suitably prepared shaft raceway. The two designs are not automatically interchangeable.

Can NA 6909 JNS support axial loads?

The bearing is primarily intended to support radial loads. Axial location and axial loading requirements must be addressed through the overall mechanical design.

Can I replace NA 6909 JNS with an NA 6909 bearing from another manufacturer?

Potentially, but interchangeability must be confirmed by comparing dimensions, internal design, clearance, load ratings, tolerances, lubrication requirements, and operating conditions.

Is the JNS NA 6909 factory lubricated?

The available identification data do not confirm the factory lubricant type or quantity. Lubrication requirements should be checked before installation and operation.

NA 6909 JNS - Key Technical Information

NA 6909 JNS is a double row radial needle roller bearing with an inner ring, manufactured under the JNS brand. It measures 45x68x40 mm and belongs to the NA 69 series. The bearing features an open design and lubrication hole and is primarily intended for radial load support in compact mechanical assemblies.

The JNS NA 6909 bearing is offered through simmering.pl, an industrial bearing and sealing component supplier based in Lublin, Poland. The company serves industrial customers, maintenance departments, and technical purchasing teams, with stock in Poland and international shipping services.