Single Row Angular Contact Ball Bearings

Detail Introduction :

Single row angular contact ball bearings can only withstand a direction of axial load, this bearing in bearing pure radial load, because the rolling body load line of action and radial load line of action is not in the same radial plane, resulting in internal axial force, so must be installed in pairs.

Single row angular contact ball bearings is generally separated design, the inner and outer ring of the two sides of the shoulder height is different, in the processing will be one side of the shoulder processing lower, so that the bearing can be loaded into more steel balls, which can improve the load capacity of the bearing.

In Skf bearing, single row angular contact ball bearing design is very delicate, simple structure, generally by the inner ring, outer ring, single row rolling body and keep frame four parts, the role of the inner ring is to match with the shaft combined with the shaft rotation; outer ring role is to match with the bearing seat, play a supporting role.

Single row rolling body is evenly distributed between the inner ring and outer ring with the help of cage, its shape, size and number directly affect the performance and life of rolling bearings; cage can make rolling body evenly distributed, guiding the rolling body rotation and lubrication.

Single row angular contact ball bearings are widely used.

High-speed precision angular contact ball bearings are mainly used for high speed rotating occasions with lighter load, requiring high precision, high speed, low temperature, low vibration and certain service life. Often used as the support of high-speed electric spindles installed in pairs, is the key supporting parts of high-speed electric spindles for internal surface grinding machines.

Single-row angular contact ball bearings can be used in machine tool spindles, high-frequency motors, gas turbines, centrifugal separators, small car front wheels, differential pinion shafts, booster pumps, drilling platforms, food machinery, indexing heads, welding machines, low-noise cooling towers, electromechanical equipment, painting equipment, machine tool slot plates, arc welding machines, etc. 

The bearings used under general conditions, its inner and outer ring, rolling body are made of high carbon chromium bearing steel, but in some applications, such as in the requirements of ultra-high speed, wear resistance, low temperature rise, long life and high reliability and other places, the performance of steel bearings can not meet the requirements of the use of the situation, then, it is necessary to use a more excellent performance bearing materials.

Single row angular contact ball bearing and the same structure, between the size of the standard steel angular contact ball bearing, compared with the advantages of high speed performance, high rigidity, low friction heat, long life, etc.. It can significantly improve the speed, rigidity, reliability and productivity of the spindle, and greatly reduce the frictional heat of the spindle and prolong the service life of the main machine.

Features of single row angular contact ball bearing.
Single row angular contact ball bearing in bearing radial load, will cause additional axial force, often need to be installed with other bearing group bearing bearing bearing reverse square dean axis called load. Therefore, angular contact ball bearing is usually used in double, triple, quadruple or even quintuple grouping, the limit speed of angular contact ball bearing is higher.

Single row angular contact ball bearing has high bearing capacity, the lower shoulder can be a large number of balls into the bearing, so that it has a relatively high bearing capacity. Their good running characteristics allow for fast acceleration and deceleration. Easy mounting of universal matched bearing, no adjustment is needed to get the correct internal clearance or preload.

Single row angular contact ball bearings can be divided into separated angular contact ball bearings, non-separated angular contact ball bearings and successfully matched angular contact ball bearings.

Separate angular contact ball bearings have no locking ports on the outer ring raceway side and can be separated from the inner ring, cage and ball assembly, so they can be mounted separately. These are mostly miniature bearings with an inner diameter of less than 10mm, and are used in devices with high requirements for dynamic balance, noise, vibration and stability, such as gyroscopic rotors and micro motors.

Non-separable angular contact ball bearings have locking grooves, so the two rings can not be separated, according to the contact angle is divided into three:
Contact angle α = 40 °, suitable for bearing large axial load; contact angle α = 25 °, mostly used for precision spindle bearings; contact angle α = 15 °, mostly used for larger size precision bearings.

Pairs of angular contact ball bearings are used to bear radial load and axial load at the same time, can also bear pure radial load and axial load in either direction. This kind of bearing by the production plant according to certain preload requirements, optional combination into pairs, to provide users with. When the bearing is installed in the machine after tightening, completely eliminate the clearance in the bearing, and make the collar and outline ball in the preload state, thus improving the combination of bearing steel.

In addition, there is a kind of Single row angular contact ball bearing which can be paired in any way.This skf single row angular contact ball bearing can be combined in any way such as two back to back, two face to face or two tandem by special processing, and the axial clearance of the paired combination can be chosen according to the need.

In short, single row angular contact ball bearings have many advantages, simple design, suitable for high speed, even very high speed, and in operation is very strong and durable, almost no maintenance. Support the rotating shaft and shaft parts, and maintain the normal working position and rotational accuracy of the shaft, rolling bearings are easy to use and maintain, reliable work, good starting performance, and high load carrying capacity at medium speed.

Detailed description of Single row angular contact ball bearings can be found in the following.

1.Permissible speed

For bearings arranged in pairs, the limiting speed should be reduced to approximately 80% of the value quoted for a single bearing.

The speed ratings in the product table indicate:
1.the reference speed, which enables a quick assessment of the speed capabilities from a thermal frame of reference
2.the limiting speed, which is a mechanical limit that should not be exceeded unless the bearing design and the application are adapted for higher speeds

Bearing pairs
For bearings arranged in pairs, the limiting speed remains unchanged but the reference speed should be reduced to approximately 80% of the value quoted for a single bearing.

2、Operating temperature and speed

The relationships between the temperature and power loss of components within an application is complex and these factors, in turn, have interdependencies with many others such as bearing sizes, loads and lubrication conditions.

They influence many performance characteristics of an application and its parts, and do so in various ways depending on the operational state, such as at start-up or in normal operation, when steady-state conditions have been reached.

Estimating the operating temperature and verifying speed limitations is a critical aspect of the analysis of an application.

This section provides details of these primary relationships, and guidance on what to consider.

Bearing operating temperature and heat flow

Temperature has a major influence on many performance characteristics of an application. The heat flow to, from and within an application determines the temperature of its parts.

The operating temperature of a bearing is the steady state temperature it attains when running and in thermal equilibrium with its surrounding elements. The operating temperature results from (diagram 1):

1.the heat generated by the bearing, as a result of the combined bearing and seal frictional power loss
2.the heat from the application transferred to the bearing via the shaft, housing, foundation and other elements in its surroundings
3.the heat dissipated from the bearing via the shaft, housing, foundation, lubricant cooling system (if used) and other cooling devices

The bearing operating temperature depends as much on the application design as on the bearing generated friction. Therefore, the bearing, its adjacent parts and the application should all be thermally analysed.

Bearing size, operating temperature and lubrication conditions

For a given bearing type, the bearing size, operating temperature and lubrication conditions are interdependent as follows (diagram 2):

1.Bearing size is selected based on bearing load, speed and lubrication conditions.
2.Operating temperature is a function of the bearing load, size, speed and lubrication conditions.
3.Lubrication conditions depend on the operating temperature, the viscosity of the lubricant and the speed.

These interdependencies are dealt with by taking an iterative approach to the analysis, in order to achieve an optimum design for a bearing arrangement and select the most appropriate components for it.

When using Single row angular contact ball bearings, its temperature and speed have certain requirements. The above describes the relevant content of working temperature and speed. Next, let's take a look at its temperature limit.

3、Temperature limits

The permissible operating temperature for angular contact ball bearings can be limited by:
1.the dimensional stability of the bearing rings and balls
2.the cage
3.the seals
4.the lubricant
Where temperatures outside the permissible range are expected, contact SKF.

Bearing rings and balls
The bearings are heat stabilized up to at least 150 °C (300 °F).

Cages
Steel, brass or PEEK cages can be used at the same operating temperatures as the bearing rings and balls. For temperature limits of cages made of other polymer materials, refer to Polymer cages.

Seals
The permissible operating temperature for NBR seals is –40 to +100 °C (–40 to +210 °F). Temperatures up to 120 °C (250 °F) can be tolerated for brief periods.
Typically, temperature peaks are at the seal lip.

Lubricants
Temperature limits for greases used in sealed SKF angular contact ball bearings are provided in table 1. For temperature limits of other SKF greases, refer to Selecting a suitable SKF grease.

When using lubricants not supplied by SKF, temperature limits should be evaluated according to the SKF traffic light concept

4、Designs and variants

The SKF standard assortment of single row angular contact ball bearings (fig. 1) includes:
1.bearings in the 72 B(E) and 73 B(E) series with 40° contact angle
2.some sizes in the 70 B series
3.sealed bearings:
（1）in series 72 B(E) (15 ≤ d ≤ 55 mm)
（2）in series 73 B(E) (12 ≤ d ≤ 50 mm)
4.bearings in the 72 AC series with 25° contact angle (15 ≤ d ≤ 70 mm)
5.bearings in the 73 AC series with 25° contact angle (17 ≤ d ≤ 70 mm)
6.some large size bearings with a flanged outer ring
7.SKF inch bearings (ALS and AMS series)

Basic design bearings
1.are intended for adjusted arrangements where only one bearing is used at each bearing position and are not suitable for mounting immediately adjacent to each other
2.have Normal tolerances on bearing width and standout of the rings
3.have different performance capabilities compared with SKF Explorer bearings

Bearings for universal matching
1.are available with 25° and 40° contact angles
2.are intended to be used in sets
3.have ring widths and standouts manufactured to tight tolerances
4.can also be used in place of basic design bearings for arrangements with single bearings, as they typically have higher precision, and increased load carrying capacity and speed capability.
When two bearings are mounted immediately adjacent to each other, a given internal clearance or preload or an even load distribution between the two bearings is obtained without the use of shims or similar devices.
Bearings for universal matching are identified by the following suffixes:
1.CA, CB, CC or G for internal clearance
2.GA, GB or GC for preload
When ordering, indicate the number of individual bearings required and not the number of sets.
Paired mounting
Tandem arrangement (fig. 2)

1.is used where the load carrying capacity of a single bearing is inadequate
2.shares the radial and axial loads equally
3.has parallel load lines
4.can accommodate axial loads in one direction only
If axial loads act in both directions, a third bearing, adjusted against the tandem pair, must be added.
Back-to-back arrangement (fig. 3)

1.provides a relatively stiff bearing arrangement
2.can accommodate tilting moments
3.has load lines that diverge from the bearing axis
4.can accommodate axial loads in both directions, but only by one bearing in each direction
Face-to-face arrangement (fig. 4)

1.is less sensitive to misalignment but not as stiff as a back-to-back arrangement
2.has load lines that converge towards the bearing axis
3.can accommodate axial loads in both directions, but only by one bearing in each direction

Bearings with 25° contact angle (AC series)
1.have a raceway geometry optimized for high speeds
2.have reduced sensitivity to axial loading and misalignment, including the ability to accommodate two times higher peak loads before edge stresses can occur
3.are equipped with an optimized machined brass cage as standard
Compared with bearings with 40° contact angle, benefits include:
1.20% higher limiting speeds
2.higher radial load carrying capacity (by trading off lower axial load carrying capacity)
3.increased robustness when used as the backup bearing in sets that are predominantly loaded in one direction

Sealed bearings
SKF supplies single row angular contact ball bearings in the 72 B(E) and 73 B(E) series, which are sealed on both sides.

Non-contact seals
1.are identified by the designation suffix 2RZ (fig. 5)

2.have no additional frictional moment
3.have the same limiting speeds as open bearings
4.form an extremely narrow gap with the inner ring shoulder
5.are made of sheet steel reinforced NBR (oil and wear-resistant)
6.make good, positive contact with the recess in which they are fitted
When capped bearings must operate under certain conditions, such as very high speeds or high temperatures, grease may appear between the inner ring and capping device. For bearing arrangements where this would be detrimental, appropriate actions should be taken.

Greases for sealed bearings
Bearings sealed on both sides are lubricated for the life of the bearing and are virtually maintenance-free. They are filled as standard with high performance polyurea grease (GXN, no designation suffix, table 1).

Non-standard greases are available on request. Grease life for capped bearings 1.is presented as L10, i.e. the time period at the end of which 90% of the bearings are still reliably lubricated (diagram 1)

2.depends on:
the operating temperature
the ndm value
grease performance factor (GPF) (table 1)

The indicated grease life is valid under this combination of operating conditions:
1.horizontal shaft
2.inner ring rotation
3.light load (P ≤ 0,05 C)
4.operating temperature within the green temperature zone of the grease (table 1)
5.stationary machine
6.low vibration levels
Where the operating conditions differ as described below, the grease life obtained from the diagrams should be adjusted:
1.vertical shafts → 50% of the obtained value
2.heavier loads (P > 0,05 C) → apply reduction factor (table 2)

Cages
SKF single row angular contact ball bearings are fitted with one of the cages shown in table 3. The machined brass cage (designation suffix M) has been upgraded as follows:
1.optimized cage pocket geometry
2.a smaller cross section and reduced mass
3.increased material strength with reduced lead content
When used at high temperatures, some lubricants can have a detrimental effect on polyamide cages. Complete guide to single row angular contact ball bearings.
There are many kinds of bearings, skf single row angular contact ball bearings as a kind of bearing has been very widely used. This guide provides a detailed introduction to single row angular contact ball bearings, and we believe the following will be of great help to you.

1、What is single row angular contact ball bearings?

Angular contact ball bearings have a contact angle of 40 degrees, so they can withstand a large axial load. Double row angular contact ball bearings can withstand large radial load-based radial and axial combined load and moment load, limiting the axial displacement of both sides of the shaft. Single row angular contact ball bearing can only withstand a direction of the axial load, in bearing radial load, will cause additional axial force, must be applied to the corresponding reverse load, therefore, this kind of bearing are generally used in pairs.

2、What is the installation method of single row angular contact ball bearings?

Single row angular contact ball bearings can withstand both radial load-based diameter, axial combined load, can also withstand pure radial load, generally need to be used in pairs, do any pair of bearing combination, pair installation of bearings according to its outer ring different end combinations are divided into: back-to-back configuration, face-to-face configuration, tandem configuration, in addition to the tandem configuration, the other two configurations can withstand any direction of the axial load.

Tandem configuration configuration load line parallel, radial and axial load is evenly shared by the bearing, but can only withstand the role of axial load in one direction. If the axial load in the opposite direction, or if there is a composite load, it is necessary to add a third bearing relative to the tandem pair bearing adjustment. Can also be in the same bearing in series with three or more bearings, but can only withstand the axial load in a single direction.

Back-to-back configuration of the bearing load line to the bearing axis separate, face-to-face configuration of the bearing load line to the bearing axis convergence, both can withstand the axial load acting in two directions, but each direction of the load can only be carried by a bearing. The back-to-back bearing provides a relatively high rigidity bearing configuration, while the rigidity of the face-to-face configuration is lower.

3、How to maintain single row angular contact ball bearings?

In order to give full play to the role of bearings and long-term maintenance of its appropriate performance, bearings are required for maintenance and maintenance, usually do a good job in this regard, timely detection of problems, so as to avoid unnecessary losses, can greatly improve efficiency, the following are some maintenance methods.

(1) timely check the state of the bearing, disassembly, if you want to continue to use, disassembly process should be careful not to damage the parts.
(2) Cleaning should first soak the bearing with diesel oil or kerosene, after cleaning, gently shake in the radial axial direction by hand to determine whether there is loose or excessive clearance, if the ball is found to have serious wear, should be replaced in a timely manner.
(3) After the cleaning inspection of the bearing is completed, dry or dry the cleaning agent with a white cloth, melt the appropriate amount of grease or yellow dry oil with a civil fire, and then put the tested bearing into the barrel to soak until no bubbles overflow until the grease cools down and take out the bearing.
(4) Determine whether the angular contact ball bearing is loose and serious, the phenomenon of excessive rotating noise, if there is a serious defect to be eliminated in time, replace the bearing with a new one of the same type, not to save money to continue to use.
(5) Refueling should be done in a dust-free environment, one hand slowly turn the bearing, the other hand will squeeze the oil into the bearing cavity, and finally wipe the grease outside the bearing with a soft cloth or paper towel, and then assemble the bearing to the pulley according to the original shape.

4、What are the advantages and disadvantages of single row bearings?

Single row bearings have the advantages of low frictional resistance, flexible start, high efficiency, high bearing capacity per unit width, greatly reducing the consumption of non-ferrous metals, easy interchangeability, convenient lubrication and maintenance. However, its high contact stress, poor impact resistance, low life expectancy under heavy load at high speed, not suitable for high speed occasions with impact and instantaneous overload.

Compared with double row bearings and multi-row bearings, single row bearings have small bearing capacity, and can not bear two-way axial load while bearing radial load, and low vibration damping capacity, noise during operation, large radial profile size, and high cost for small batch production of special rolling bearings.

5、How to preload angular contact ball bearings?

Radial preload: This method is usually used in bearing radial load tapered bore bearings, spindle bearings are single row angular contact ball bearings consisting of solid inner ring, outer ring, ball, and cage assembly with a solid window cage, they can not be removed, these bearings can be open, but also sealed. Typical examples are double-row precision short cylindrical roller bearings using nuts to adjust the axial position of such bearings relative to the tapered journal, so that the inner ring has the right amount of expansion and get the radial negative clearance, this method is mostly used in machine tool spindles and jet engines.

Axial preload: broadly speaking, can be divided into fixed pressure preload and positioning preload two. Constant pressure preload is the use of coil springs, disc springs, etc. so that the bearing to get the appropriate preload method. The rigidity of the preload spring is generally much smaller than the rigidity of the bearing, so the relative position of the bearing in the fixed pressure preload will change in use, but the amount of preload is approximately the same.

In the positioning preload, you can adjust the size of the bushing or shim to get the right preload; you can also measure or control the starting friction torque to get the right preload; you can also directly use the pre-adjusted preload amount of pairs of duplex bearings to achieve the purpose of preload, after the axial preload of the bearing, the relative position will not change when using.

6、What is the difference between angular contact ball bearings and deep groove ball bearings?

Deep groove ball bearings are the most commonly used rolling bearings, its structure is simple, easy to use, mainly used to bear radial load, but when increasing the bearing radial clearance, has a certain angular contact ball bearings performance, can withstand the diameter, axial joint load, suitable for high-speed rotation and the requirements of low noise, low vibration occasions.

Angular contact ball bearing collar and ball contact angle between the standard contact angle of 15/25 and 40 degrees three, the greater the contact angle is the greater the axial load capacity, the smaller the contact angle is more conducive to high-speed rotation, single row bearing can withstand radial load and one-way axial load, DB combination, DF combination and double row angular contact ball bearing can withstand radial load and two-way axial load.

Deep groove ball bearing and angular contact ball bearing inner ring size, structure, but the outer ring size, structure is different. Deep groove ball bearing outer ring groove on both sides of the double shoulder, and angular contact ball bearings are generally single shoulder; deep groove ball bearing outer ring groove position and angular contact ball bearings are different, non-center position, its specific value and the degree of contact angle.

The use between the two is also different, deep groove ball bearings are suitable for bearing radial force, smaller axial force, shaft radial joint load and moment load, while angular contact ball bearings can withstand radial load, larger one-way axial load, duplex pair can withstand two-way axial load and moment load. In addition, the same size of the angular contact ball bearing limit speed is higher than the deep groove ball bearing.

7、What types of single row rolling bearings are there?

(1) Needle roller bearings: equipped with thin and long rollers, so the radial structure is compact, its inner diameter size and load capacity with other types of bearings, the outer diameter of the smallest, especially suitable for radial installation size restrictions on the support structure.
(2) deep groove ball bearing: its structure is simple, easy to use, is the most widely used category, mainly used to bear radial load, can also bear a certain axial load.
(3) Angular contact bearings
Angular contact ball bearing limit speed is high, can simultaneously withstand the load and axial load, can also withstand pure axial load, its axial load capacity by the contact angle decision, and with the contact angle increases and increases.
(4) Spherical ball bearing
Spherical ball bearing has two rows of steel balls, inner ring has two raceways, outer ring raceway for the inner spherical shape, has the performance of automatic centering. Can automatically compensate for the coaxiality error due to the shaft winding and shell deformation, suitable for supporting the seat hole can not ensure strict coaxiality of the parts.
(5) Spherical roller bearing
Spherical roller bearings have two rows of rollers, mainly used to bear radial load, but also can withstand the axial load in either direction. This kind of bearing radial load capacity is high, especially suitable for heavy load or vibration load work, but can not bear pure axial load; spherical performance is good, can compensate for the same bearing error.

There are also cylindrical roller bearings, tapered roller bearings, spherical ball bearings with seats, thrust roller bearings thrust ball bearings, etc., here will not tell, each bearing has its own characteristics and uses, you can choose according to their needs.

8、How to choose the type of bearing?

The selection of bearing should be based on the working load, speed, shaft stiffness and other requirements of the bearing. When the speed is high, the load is small, and the rotation accuracy is high, choose the ball bearing; when the speed is low, the load is large and there is impact, choose the roller bearing. Selection of bearings should also consider the alignment performance, all kinds of bearings inside and outside the axis of the relative tilt angle is limited, more than the limit angle, will make life reduced.

At the same time bear radial load and axial load bearing, should distinguish between different situations to choose the type of bearing. Radial load can be mainly used deep groove ball bearings; axial load than the radial load is much larger than the combination of thrust bearing and radial bearing structure, in order to bear the axial load and radial load respectively; radial load and axial load are very large when you can choose angular contact ball bearings or tapered roller bearings.

Bearings Model: