In order to allow full utilisation of the load carrying capacity of the bearings and thus also achieve the requisite rating life, the bearing rings must be rigidly and uniformly supported by means of contact surfaces over their entire circumference and over the entire width of the raceway. Support can be provided by means of a cylindrical seating surface. The seating and contact surfaces should not be interrupted by grooves, holes or other recesses. The accuracy of mating parts must meet specific requirements ➤ Table to ➤ Table.

Bearings of series 38..-B(-2RSR, -2Z), 30..-B(-2RSR, -2Z), 32..-B(-2RSR, ‑2Z), 32..-BD(-2HRS), 33..-B(-2RSR, -2Z), 33..BD(-2HRS) are self-retaining. They do not have filling slots in the end faces of the bearings rings ➤ Figure. Bearings of series 32..-BD and 33..-BD have an optimised internal construction.

SKFangular contact bearing

The bearings are available with α = 25°, 30°, 35° and 45° ➤ Figure to ➤ Figure. The axial load carrying capacity increases with the size of the contact angle. In bearings without filling slots, it is the same in both directions.

This permits direct comparisons between bearings with the same load carrying capacity. The upper limit value is given in each of the diagrams. This means that the average noise level of the bearings is lower than illustrated in the diagram.

The values given in the product tables are valid for oil lubrication in the case of bearings without seals or shields and for grease lubrication where bearings are supplied greased and with seals or shields.

Angular contact ball bearings of series 32 and 33 are self-retaining. They have filling slots on one end face of the bearing ring for filling the bearings with rolling elements ➤ Figure. The nominal contact angle is α = 35°.

Most modern car systems today are outfitted with 4 stroke gas engines that consist of an exhaust stroke, an intake stroke, a compression stroke, as well as a power stroke. In the 4-stroke cycle, the crankshaft rotates twice while the camshaft does it once. For this rotation to take place properly, it relies on a system known as mechanical timing.

Bearings can also be supplied with an axial internal clearance which is larger or smaller than CN (C3, C4 or C2). In this case, please contact Schaeffler.

Open bearings and bearings with seals on both sides are greased using a high quality grease. Bearings sealed on both sides are maintenance-free for many applications, i.e. they do not require relubrication.

Angular contact bearingsize chart

Double row bearings correspond in their structure to a pair of single row angular contact ball bearings in an O arrangement, but they are narrower to a certain extent. They differ in the size of the contact angle α and the design of the bearing rings. Due to the manufacturing processes used, open bearings, which are also available with sealing washers or sealing shields, can have turned recesses in the outer and/or inner ring for sealing washers or sealing shields.

In addition to the data in this chapter, the following chapters in Technical principles must also be observed in the design of bearing arrangements:

Angular contact ball bearings without seals and with seals on one side of series 32.., 33.., 33..-DA, 32..-BD and 33..-BD are not preserved or greased. These bearings must be lubricated with oil or grease.

Cylindrical roller bearings

Timing belts are constructed using a mix of rubber and other materials such as nylon. When the timing belt was invented almost 50 years ago, virtually every car was outfitted with a timing belt.

We therefore reserve the right to make changes to the data and illus­trations in this catalogue. This catalogue reflects the status at the time of printing. More recent publications released by us (as printed or digital media) will automatically precede this catalogue if they involve the same subject. Therefore, please always use our electronic product catalogue to check whether more up-to-date information or modification notices exist for your desired product.

With proper maintenance of your Kia vehicle, it is quite possible to avoid timing chain replacement. However, you must do your best to keep up with the maintenance schedule otherwise it could lead to problems with your engine that you want to avoid completely.

For bearings with contact seals, no speed ratings are defined in accordance with DIN ISO 15312:2004. As a result, only the limiting speed nG is given in the product tables for these bearings.

The Schaeffler Noise Index (SGI) has been developed as a new feature for comparing the noise level of different bearing types and series. As a result, a noise evaluation of rolling bearings can now be carried out for the first time.

The Schaeffler Noise Index is an additional performance characteristic in the selection of bearings for noise-sensitive applications. The specific suitability of a bearing for an application in terms of installation space, load carrying capacity or speed limit for example, must be checked independently of this.

The SGI value is based on the maximum permissible noise level of a bearing in accordance with internal standards, which is calculated on the basis of ISO 15242. In order that different bearing types and series can be compared, the SGI value is plotted against the basic static load rating C0.

The inner ring halves are matched to the particular bearing and must not be interchanged with those of other bearings of the same size.

Because they are made from rubber, timing belts tend to be quieter compared to timing chains. However, this same quality is also what makes them susceptible to damage and must be replaced when they start wearing out before the damage becomes too extensive.

NSK Spherical Rollerbearingpdf

When using bearings with plastic cages, compatibility between the lubricant and the cage material must be ensured if synthetic oils, lubricating greases with a synthetic oil base or lubricants containing a high proportion of EP additives are used.

The accuracy of the bearing seat on the shaft and in the housing should correspond to the accuracy of the bearing used. For double row angular contact ball bearings with the tolerance class Normal, the shaft seat should correspond to a minimum of standard tolerance grade IT6 and the housing seat to a minimum of IT7; with tolerance class 6, the shaft seat should correspond to a minimum of IT5 and the housing seat to IT6. Guide values for the geometrical and positional tolerances of bearing seating surfaces ➤ Table, tolerances t1to t3 in accordance with ➤ link. Numerical values for IT grades ➤ Table.

If shock type loads occur, tight fits (transition fit or interference fit) are required to prevent the rings from coming loose at any point. Clearance, transition or interference fits ➤ link.

Bearings with a split inner ring are intended for higher axial loads. As a result, they generally also have a tighter fit than unsplit bearings. Their normal internal clearance corresponds approximately to the internal clearance group C3 for unsplit bearings ➤ Table.

Double row angular contact ball bearing –comparison of design envelope with bearing set composed of single row angular contact ball bearings

The further fundamental information on the calculation of the equivalent dynamic bearing load must be observed ➤ section.

In angular contact ball bearings of series 33..-DA, the inner ring is split ➤ Figure. The inner rings are not self-retaining. Filling the bearings with a large number of balls – in conjunction with the internal design of the bearing and the contact angle of 45° – allows high alternating axial loads to be supported.

The mounting and dismounting options for angular contact ball bearings, by thermal, hydraulic or mechanical methods, must be taken into consideration in the design of the bearing position.

The mounting dimensions of the shaft and housing shoulders, and spacer rings etc., must ensure that the contact surfaces for the bearing rings are of sufficient height. However, they must also reliably prevent rotating parts of the bearing from grazing stationary parts. Proven mounting dimensions for the radii and diameters of abutment shoulders. These dimensions are limiting dimensions (maximum or minimum dimensions); the actual values should not be higher or lower than specified.

Series 38..-B, 30..-B, 32..-B and 33..-B with the suffix 2RS, 2RSR and 2HRS have lip seals in axial contact on both sides and in radial contact ➤ Table. Bearings with the suffix RS, HRS and RSR are sealed on one side with lip seals in axial and radial contact.

In addition to the basic rating life L (L10h), it is also always necessary to check the static load safety factor S0 ➤ Equation.

Angular contact bearingarrangement

Standard cages and additional cage designs for double row angular contact ball bearings are made from brass, polyamide or steel ➤ Table. Other cages are available by agreement. With such cages, however, suitability for high speeds and temperatures as well as the basic load ratings may differ from the values for the bearings with standard cages.

These angular contact ball bearings are not self-retaining. As a result, the outer ring with the ball and cage assembly can be mounted separately from the two inner ring halves. This gives simplified mounting of the bearings.

Warranties include 10-year/100,000-mile powertrain and 5-year/60,000-mile basic. All warranties and roadside assistance are limited. See retailer for warranty details.

The bearings are not suitable for the compensation of angular misalignments. In addition, misalignments induce internal forces, which not only lead to higher temperatures, but also to a reduction in the bearing rating life.

Super precision bearings

The main dimensions of double row angular contact ball bearings correspond to DIN 628-3:2008. Nominal dimensions of double row angular contact ball bearings ➤ link.

Of central interest to Schaeffler is the further development and optimisation of its products and the satisfaction of its customers. In order that you, as the customer, can keep yourself optimally informed about the progress that is being made here and with regard to the current technical status of the products, we publish any product changes which differ from the printed version in our electronic product catalogue.

The limiting dimensions for chamfer dimensions correspond to DIN 620‑6:2004. Overview and limiting values ➤ section. Nominal value of chamfer dimension ➤ link.

Comparison of basic dynamic load ratingCr – bearing series 33..‑BD‑XL, bore code 02 to 16, with a bearing which is not of X-life quality (33..-B)

For bearings with tolerance class Normal, a minimum of IT6 should be provided for the shaft seat and a minimum of IT7 for the housing seat

In the case of unsealed bearings, sealing must be carried out by the adjacent construction. The sealing system should reliably prevent:

Due to the weaker rubber materials, timing belts can only last between 60,000 and 100,000 miles before they have to be replaced. Timing chains are also used more commonly in small vehicles that require less power and performance to move around.

For high continuous temperatures and applications with difficult operating conditions, bearings with brass or sheet steel cages should be used. If there is any uncertainty regarding cage suitability, please consult Schaeffler.

The following information provided in Technical principles must be taken into consideration in the design of bearing arrangements:

In addition to supporting the rings adequately, the bearings must also be securely located in a radial direction, to prevent creep of the bearing rings on the mating parts under load. This is generally achieved by means of tight fits between the bearing rings and the mating parts. If the rings are not secured adequately or correctly, this can cause severe damage to the bearings and adjacent machine parts. Influencing factors, such as the conditions of rotation, magnitude of the load, internal clearance, temperature conditions, design of the mating parts and the mounting and dismounting options must be taken into consideration in the selection of fits.

Aged oil and additives in the oil can impair the operating life of plastics at high temperatures. As a result, stipulated oil change intervals must be strictly observed.

Linearbearing

Timing chain, on the other hand, can break off when the engine is experiencing a high rpm or a low one. If the engine is at a high rpm, it can destroy anything that it comes into contact with. If it is at a low speed, the belt might simply slide off and only cause minimal damage.

The limiting speed nG is the kinematically permissible speed of the bearing. Even under favourable mounting and operating conditions, this value should not be exceeded without prior consultation with Schaeffler ➤ link.

The designation of bearings follows a set model. Examples ➤ Figure and ➤ Figure. The composition of designations is subject to DIN 623-1 ➤ link.

It is the timing system that is responsible for engaging numerous components of the internal combustion engine such as the valves and pistons to rotate and move as designed so that the engine can continue to run smoothly and perform as you expect it to. There are two primary varieties of timing systems; a timing belt and a timing chain.

As the name suggests, timing chains are constructed out of metal. Timing chains are preferred by some because they are strong and reliable. However, chains produce a lot of noise. Timing chains can last anywhere between 150,000 and 200,000 miles before they require repair or sustain damage. But once they do, they must be replaced without fail as they can break off entirely, therefore causing the engine to fail. In some cases, broken timing chains can lead to engine replacement when repair becomes out of the question.

Double row angular contact ball bearings with unsplit inner ring of the basic design have the axial internal clearance CN (group N) in accordance with DIN 628-3:2008 ➤ Table.

The modern combustion system in your Kia would not be the magical thing of wonder that it is without a Kia Timing Belt and Timing Chain. In an engine, one of the most essential aspects that allow it to run to properly is its timing system.

In order that no slippage occurs between the contact partners, the double row angular contact ball bearings must be constantly subjected to a sufficiently high load. Based on experience, a minimum radial load of the order of P ＞ C0r/100 is thus necessary. In most cases, however, the radial load is already higher than the requisite minimum load due to the weight of the supported parts and the external forces.

Bearing series with the suffix 2Z have sheet steel sealing shields on both sides. Bearings with the suffix 2RZ are fitted with rubberised gap seals on both sides.

In conclusion, these advantages improve the overall cost-efficiency of the bearing position significantly and thus bring about a sustainable increase in the efficiency of the machine and equipment.

The Schaeffler Mounting Handbook MH 1 gives comprehensive information about the correct storage, mounting, dismounting and maintenance of rotary rolling bearings http://www.schaeffler.de/std/1B68. It also provides information which should be observed by the designer, in relation to the mounting, dismounting and maintenance of bearings, in the original design of the bearing position. This book is available from Schaeffler on request.

As you may already know by now, all combustion systems are different. In some cars, you will find a timing belt in some a timing chain. The timing system needs intermittent or regular maintenance. Otherwise, if the system is not properly looked after, it can cause the entire engine to fail.

The calculation of P is dependent on the nominal contact angle α of the bearing, the load ratio Fa/Fr and the calculation factors from ➤ Equation to ➤ Equation.

Timing belts and chains may be affected by the age of your Kia vehicle as well as how often you use it. Timing belts tend to break when the engine is starting or shutting down because that is when the tension on the belt is greatest.

In addition to high radial loads, double row angular contact ball bearings can also support axial forces in both directions and tilting moments ➤ Figure. They are highly suitable for bearing arrangements with rigid axial guidance.

As a tight fit alone is not normally sufficient to also locate the bearing rings securely on the shaft and in the housing bore in an axial direction, this must usually be achieved by means of an additional axial location or retention method. The axial location of the bearing rings must be matched to the type of bearing arrangement. Shaft and housing shoulders, housing covers, nuts, spacer rings and retaining rings etc., are fundamentally suitable.

The tolerances for the dimensional and running accuracy of double row angular contact ball bearings correspond to tolerance class Normal in accordance with ISO 492:2014; the dimensional and running tolerances of bearings with the suffix BD correspond to the tolerance class 6 in accordance with ISO 492:2014. Tolerance values in accordance with ISO 492 ➤ link and ➤ link.

Due to their special technical features, double row X-life angular contact ball bearings are highly suitable for bearing arrangements in:

Rolling bearings are well-proven precision machine elements for the design of economical and reliable bearing arrangements, which offer high operational security. In order that these products can function correctly and achieve the envisaged operating life without detrimental effect, they must be handled with care.

The roughness of the bearing seats must be matched to the tolerance class of the bearings. The mean roughness value Ra must not be too high, in order to maintain the interference loss within limits. The shafts must be ground, while the bores must be precision turned. Guide values as a function of the IT grade of bearing seating surfaces ➤ Table.

For a description of the suffixes used in this chapter see ➤ Table and medias interchange http://www.schaeffler.de/std/1B69.

The thermal speed rating nϑr is not an application-oriented speed limit, but is a calculated ancillary value for determining the thermally safe operating speed nϑ ➤ link.

In the mounting of non-separable (self-retaining) angular contact bearings, the mounting forces must always be applied to the bearing ring with a tight fit.

SKFangular contact bearingcatalogue PDF

These series must be fitted such that the main load direction is supported by the row of balls without filling slots under axial load.

Bearings of series 32..-BD and 33..-BD are X-life bearings ➤ link. These bearings exhibit considerably higher performance than standard double row angular contact ball bearings ➤ Figure. This is achieved, for example, through the modified internal construction, higher surface quality of the contact surfaces and optimised cage design, as well as through the improved quality of the steel and rolling elements.

Calculation of the equivalent static bearing load P0 is dependent on the nominal contact angle α and the calculation factors ➤ Equation to ➤ Equation.