Bearings Size Chart - RHD Bearings - bearing dimensions chart pdf

2024-10-14 06:25:18

Dynamic load ratingball bearings

Our determination to remain specialised gives us a high level of product knowledge, providing bearing and lubrication solutions to existing or potential customers, whether individuals or large corporations. We don’t just sell bearings, we help to solve your problems. - Chris Johnson, managing director of SMB Bearings.

Dynamic load ratingpdf

Static loads approaching this figure may be tolerable for certain applications but not where any smoothness or accuracy is required. Static load ratings for stainless steel bearings are approximately 75 per cent –to 80 per cent of the load ratings for chrome steel bearings.

Needle bearings have the advantage of greater load carrying capability vs. ball bearings. Theoretical contact is a line (needle roller bearings) compared to a point (ball bearings).

These figures are used in the calculation of life ratings, but bearings should not be subjected to anywhere near such loads in normal application unless you don't expect them to last very long.

Heavy duty bearing types such as 6200 or 6300 series may take axial loads of up to 50 percent of the static radial load rating. Thin-section deep groove ball bearings can only support axial loads of between 10 and 30 percent of the bearing's static radial load rating due the shallower raceways.

Dynamic load ratingof bearing

By choosing the right type of bearing and considering key factors in the battle to control radial and thrust loads, engineers can ensure they continue to innovate while delivering the highest levels of accuracy, smoothness and bearing life.

Dynamic radial load rating is officially defined as: "the constant stationary radial load in which 90 per cent of a group of identical chrome steel bearings, with only the inner ring rotating, can endure for one million revolutions before the first signs of fatigue develop."

The load capacity of a bearing may be limited by the lubricant. Certain lubricants are only suitable for light loads while others are designed for high load applications. Load ratings are higher for full complement bearings (see “bearing retainers” in the technical menu). The axial load capacity of a radial ball bearing can be increased by specifying loose radial play.

Dynamic load ratingformula

Full complement ball bearings use a filling slot machined into the inner and outer rings. Under axial load, this slot can interfere with ball rotation so full complement bearings are not recommended for axial loads.

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There are a wide variety of needle roller designs that Hartford Technologies produces. Plastic molded retainers coupled with bearing grade steel rollers are one option. Alternative needle roller bearing designs include a metal stamped cage and chrome steel needle rollers. Also, sometimes the cage / retainer is machined.

Dynamic loadcapacity

Static radial load rating refers to the purely radial load (or axial load for thrust bearings) which will cause a total permanent deformation of the balls or raceway.

While in other cases, there is no cage. “Full complement” needle roller bearings use the maximum amount of rollers. Occasionally grease is used to hold the rollers in place until the needle roller bearing is assembled onto a shaft. In other cases, a temporary “plug” holds the bearing together until assembly. In yet other cases, the needle rollers hold each other together by virtue of their close proximity and geometry, similar to how a keystone works in a masonry arch.

Although thin-section bearings — where the difference between the inner and outer diameter of the bearing is small — are great for compactness and saving weight. They can only support axial loads of between 10 and 30 per cent of the bearing's static radial load rating due to the shallower raceways. Additional radial loads or moment loads will reduce thrust load capacity even further. Excessive thrust loads on a thin-section bearing can cause the balls to ride dangerously close to the top of the raceway.

A needle roller bearing decreases friction and efficiently transmits torque in applications including off-highway and oil patch equipment, drive shafts, outboard engines and air compressors. A high load needle bearing is specified for applications that involve static loads, low speeds, or oscillation.

Hartford Technologies bearing design engineers are among the most knowledgeable in the industry, and our ability to manufacture on both sides of the globe gives Hartford customers a substantial advantage in cost and flexibility. Our prototype lab and manufacturing facilities are both geared to fast turn-around, and can accommodate major programs with stringent delivery requirements. Hartford Technologies is ISO 9001, ISO/TS 16949, ISO 14001 and WBENC (woman-owned) certified.

Please note, these figures are based on pure axial load. Additional radial loads or moment (misalignment loads) will have an impact on the axial load capacity. To exceed the total recommended limits for combined loads will have a detrimental effect on bearing life.

Dynamic load ratingchart

A Newton is defined as the force that will accelerate a mass of one kilogram at the rate of one meter per second per second (or 1 m/s²). Since the force of gravity at the Earth's surface is 9.80665 m/s², 1 Kgf = 9.80665 Newtons but, to keep it simple, we say 1 Kgf = 10 Newtons.

Staticload rating

If long life is required, it is preferable to limit the actual load to between 6 per cent and 12 per cent of a bearing’s dynamic load rating. Heavier loads can be tolerated but life will be shortened.

Dynamic load ratingcalculator

One million revolutions does sound like a large number, but let's examine that a little more. A bearing will only last for just over an hour and a half (100 minutes) if you run it at around 10,000 revolutions per minute (rpm) with the maximum dynamic load applied to it.

Hartford Technologies is a multinational supplier of needle roller bearings for applications including automotive steering and seating systems, agricultural equipment, electronics products and medical devices.

There are multiple ways that manufacturers can take to ensure a bearing has a long and successful life. The first step is to limit the radial load to between 6–12 per cent of a bearing's dynamic load rating. Although a bearing is able to tolerate a much higher load, its life will be shortened.

AISI440C/KS440 stainless steel bearings will support approximately 80 - 85 per cent of the load figures for chrome steel bearings - see how they stack up here. Load ratings for thrust bearings are based on the constant axial load endured for one million revolutions. SMB Bearings’ team of experts can help with providing data for life ratings of a variety of different bearings.

We always express load ratings for bearings in Kgf (kilogramme force). That is the force exerted by a mass of one kilogramme at the Earth's surface. Elsewhere, you may see force expressed in Newtons.

Key components are a cage (also known as a separator or retainer) and needle rollers. Other components, if they are present, essentially function as inner or outer races.

The next step is to choose the right material. In SMB Bearings' experience as a specialist in thin-section, corrosion resistant, miniature bearings and ceramic bearings choosing the right type of bearing can also make all the difference. While all radial ball bearings have some thrust load capacity, it's often better to use heavy duty bearings that have deep raceways if greater thrust loads are present as these can withstand axial loads of up to 50 per cent of the static radial load rating.

Hartford Technologies manufactures needle roller bearings for radial loads that demand a low profile. These are exceptionally easy to install.

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