Single row angular contact ball bearings and Tolerances

Angular contact ball bearings

Angular contact ball bearings have raceways in the inner and outer rings that are displaced with respect to each other in the direction of the bearing axis. This means that they are designed to accommodate combined loads, i.e. simultaneously acting radial and axial loads.

The axial load carrying capacity of angular contact ball bearings increases with increasing contact angle. The contact angle α is defined as the angle between the line joining the points of contact of the ball and the raceways in the radial plane, along which the load is transmitted from one raceway to another, and a line perpendicular to the bearing axis.

SKF angular contact ball bearings are produced in a wide variety of designs and sizes. Those commonly used and included in this catalogue are
– Single row angular contact ball bearings

Single row angular contact ball bearings can accommodate axial loads acting in one direction only. Under radial loads a force acting in the axial direction is produced in the bearing, and this force must be counteracted. Consequently the bearing is normally adjusted against a second bearing.

Normally SKF single row angular contact ball bearings have one high and one low shoulder. Some bearings, particularly those of Diameter Series 8 and 9, have an inner ring with two high shoulders as in a deep groove ball bearing. The low shoulder on one or both rings enables a large number of balls to be incorporated in the bearing, thus giving the bearings a relatively high load carrying capacity. They are of non-separable design.

The contact angle α is 40°, designation suffix B, for the most common sizes. For larger bearings contact angles of 25° and 30° are the most common, designation suffixes AC and A respectively.

SKF single row angular contact ball bearings are produced in two versions
– basic design bearings (not universally matchable) – can only be used for arrangements with single row ball bearing
– bearings for universal matching.

The larger sizes are produced exclusively as universally matchable bearings.

– double row angular contact ball bearings
– four-point contact ball bearings

Single row angular contact ball bearings

Single row angular contact ball bearings can accommodate axial loads acting in one direction only. Under radial loads a force acting in the axial direction is produced in the bearing, and this force must be counteracted. Consequently the bearing is normally adjusted against a second bearing.

Normally SKF single row angular contact ball bearings have one high and one low shoulder. Some bearings, particularly those of Diameter Series 8 and 9, have an inner ring with two high shoulders as in a deep groove ball bearing. The low shoulder on one or both rings enables a large number of balls to be incorporated in the bearing, thus giving the bearings a relatively high load carrying capacity. They are of non-separable design.

The contact angle α is 40°, designation suffix B, for the most common sizes. For larger bearings contact angles of 25° and 30° are the most common, designation suffixes AC and A respectively.

SKF single row angular contact ball bearings are produced in two versions
– basic design bearings (not universally matchable) – can only be used for arrangements with single row ball bearing
– bearings for universal matching.

The larger sizes are produced exclusively as universally matchable bearings.

Dimensions

The boundary dimensions of SKF single row angular contact ball bearings are in accordance with ISO 15:1998.

Tolerances

Basic design SKF single row angular contact ball bearings for single mounting are produced to Normal tolerances. Standard design universally matchable bearings are manufactured to better than Normal tolerances.

SKF Explorer angular contact ball bearings are manufactured only as bearings for universal matching with P6 dimensional accuracy and P5 running accuracy.

Large bearings having an outside diameter of approximately 400 mm and above have dimensional accuracy to tolerance class Normal and running accuracy to tolerance class P6 as standard.

The values for tolerances correspond to ISO 492:2002.

Resource From http://www.skf.com/portal/skf/home/products?lang=en&maincatalogue=1&newlink=1_3_6

Three criteria of SKF angular contact ball bearings failure

As we all know, sales and quality of SKF angular contact ball bearings is the highest in the world. With its professional production line, operations after strict inspection, sold around the world, it provides support for industrial development in the world. The quality of SKF angular contact ball bearings is the most important basis it earned market recognition,and so, which to determine the quality of SKF angular contact ball bearings?

First, bearings industrial design is reasonable and perfect to the world-class level, stronger quality guarantees its service life. SKF angular contact ball bearings have to be rigorously forged, heat treatment, machining, grinding together of the rigorous process, and every process will affect the service life of the bearing. The quality of finished products is directly related to the failure. With continuing advances in detection technology, grinding process of degenerating layer of SKF angular contact ball bearings is a close relationship of surface quality of them.

Second,metal used in the manufacture of SKF angular contact ball bearings, used to be one of the main factors to affect the bearing failure.Now,with metallurgy technology continues to progress, raw materials extraction has been good improved and the quality of the material also greatly enhance, the quality factors of raw materials in bearing failure has been significantly declined, but at this stage, the problem still exists.

Third,selection of bearing manufacturing is a factor must be considered. Usually SKF corner contact ball bearing failure of detection in the main is according to large of Beijing material, data analysis, failure environment, forging process, find SKF corner contact ball bearing failure of main factors, and solution off, convenient SKF corner contact ball bearing of constantly optimization, using life, and effectiveness of improve. Extending the service period of SKF angular contact ball bearings, avoiding unexpected early failure in bearing. Installation conditions is one of the leading factors in the use factors, SKF angular contact ball bearings are often caused by the installation is not the right package of SKF angular contact ball bearings between the various parts of the stress change, SKF angular contact ball bearings running in an abnormal state and early failure. According to the SKF angular contact ball bearings installed, used, maintained, maintenance of technical requirements, bearing the burden of the operation load, speed, temperature, vibration, noise monitoring and checks and lubrication, unusual now to find reasons to adjust, bring it back to normal.

Structure difference between deep groove ball bearings and angular contact ball bearings

Deep groove ball bearings:
used widely rolling bearing, can bear radial load and two-way axis load, applies high-speed rotating, low noise, and low vibration of occasions. With plate dust cover or rubber sealed ring of sealed type bearing within advance fill has grease, outer ring with ended dynamic ring or convex margin of bearing, both easy axis to positioning, also easy shell within of installed, maximum load type bearing of size and standard bearing same, but both inside and outside ring also a Department fill slot, increased has mounted ball number, improve has rated load.

Angular contact ball bearing:
Among rings and ball has contact corner, standard contact corner for fifteen-twenty fifths and 40 degrees three species, contact corner more big is axis to load capacity more big, contact corner more small is more conducive to high-speed rotating, separate bearing can bear radial load and one-way axis to load, DB combination, and DF combination and the double column corner contact ball bearing can bear radial load and two-way axis to load, DT group suitable for one-way axis to load larger, and single bearing of rated load insufficient of occasions, high-speed with ACH type bearing, ball trail small, and ball number more, Mostly for machine tool spindle. In General, angular contact ball bearings are suitable for high speed and high precision rotation.

When the same inside and outside diameter, width, size deep groove ball bearings and angular contact ball bearings,they has same ring size, structure, but the ring size, structure are different:
1. outer ring raceway of deep groove ball bearings on both sides of dual abutments, and angular contact ball bearings are generally single abutments;
2. curvature of outer ring raceway of deep groove ball bearings and angular contact ball are different, which is often greater than the former;
3. position outer ring raceway of deep groove ball bearings and angular contact ball bearings of different, non-central location, its specific value be considered in the design of angular contact ball bearings, associated with the contact angle, in degrees;

In terms of use:
1. deep groove ball bearing is suitable for bear trail thrust, and smaller of axis thrust, and axis radial joint load and the torque load, and corner contact ball bearing can bear single radial load, and larger of axis to load (with contact angle different and different), double Alliance pairing (with pairing way different and vary) is can bear two-way axis to load and the torque load.
2. limiting speeds are different, with dimensions of angular contact ball bearings the speed limit is higher than that of deep groove ball bearings.

Features of the angular contact ball bearings

angular contact ball bearings The speed limit of angular contact ball bearings is higher,can bear both radial and axial loads,also be subjected to purely axial loads.Its axial load capacity is determined by the contact angle, and increases as the contact angle increases.

Single row angular contact ball bearings can only withstand axial load in one direction, and the radial load will cause additional axial force, must be applied to the appropriate reverse load, therefore the type of bearings are generally used in pairs. Double row angular contact ball bearings can withstand greater radial load as the principal of radial, axial joint bi-directional load and moment loads.It can limit axis or shell bidirectional displacements,which contact angle is 30 degrees.

Pairs of angular contact ball bearings can withstand the radial load,axial joint bi-directional load or under purely radial load. Tandem configuration can only take a single direction axial loads, other two configurations can accommodate axial loads in either direction.

This type of bearings are generally matching by manufacturers into the user, preloading of interference after installation, rings and balls are in axial preload condition, that improves stiffness and running accuracy of bearing the entire group as a single bearing.

Suffix meanings of SKF single row angular contact ball bearings

A

contact angle 30 °

AC

contact angle 25 °

B

contact angle 40 °

CA

universal distribution groups bearing, in back-to-back or face-to-face when its configurations, axial internal clearance smaller than normal

CB

universal distribution groups bearing, in back-to-back or face-to-face when its configurations, axial clearance for a common group

CC

universal distribution groups bearing, in back-to-back or face-to-face when its configurations, axial internal clearance larger than normal

DB

two back-to-back bearing

DF

two face-to-face bearings

DT

two bearing pairs arranged in tandem

E

optimized internal design

F

machined steel cage

GA

bearing the universal distribution group, in back-to-back or face-to-face when configured with light preload

GB

universal distribution group bearings in back-to-back or face-to-face when configured with preloaded

GC

universal distribution groups bearing, when configured in back-to-back or face-to-face with heavy preload

J

a pressed steel cage, ball Guide

M

machined brass cage, ball Guide, design m with the number of different identities, such as M1

N1

a locating grooves in the outer ring

N2

outer ring with two locating slots, each other into a 180 °

P

plastic cages of glass fibre reinforced polyamide 6,6, ball Guide

P5

Size accuracy and P5 running accuracy in accordance with ISO tolerance class 5

P6

Dimensional precision of the P6 and running accuracy in accordance with ISO tolerance class 6

W64

bearings with solid oil

Y

brass window-type cage of pressed steel cage, ball Guide