1. Contact angles
The contact angles ofangular contact ball bearings for machine tool are 15° and 25°. The bearing with 15° contact angle is used when the high speed and light axial load are needed, while the 25° contact angle bearing should be adopted on the contrary.
2. Four dimension series
The precision angular contact ball bearings for spindles have four dimension series, 718, 719, 70 and 72. With the same inner diameter, the outer diameter and the width of 718, 719, 70 and 72 increase in sequence.
The types and performance of angular contact ball bearings
angular contact ball bearing series | Structures | Dimension series | Bore size range | Performance |
High precision angular contact ball bearing |
718 C 718 AC 719 C 719 AC 70 C 70 AC 72 C 72 AC |
718:10~360mm 719:8~460mm 70: 8~380mm 72: 8~220mm |
High speed; Large loading capacity; Suit for grease or oil-mist lubrication |
|
High speed angular contact ball bearing(incl. hybrid ball bearing) |
H719 C H719 AC H70 C H70 AC H719 C/HQ1 H719 AC/HQ H70 C/HQ1 H70 AC/HQ1 |
H719:8~220mm H70:8~220mm H719/HQ1:8~220mm H70/HQ1:8~220mm |
Super speed; High rigidity; Suit for air-oil or oil injection lubrication |
|
Super speed angular contact ball bearing(incl. hybrid ball bearing) |
HS719 C HS719 AC HS70 C HS70 AC HS719 C/HQ1 HS719 AC/HQ HS70 C/HQ1 HS70 AC/HQ1 |
HS719:8~220mm HS70:8~220mm HS719/HQ1:8~220mm HS70/HQ1:8~220mm |
Super speed (higher than H series); High rigidity; Suit for air-oil or oil injection lubrication |
|
Super speed angular contact ball bearing with direct lubrication(incl. hybrid ball bearing) |
H719 C-DL H719 AC-DL H70 C-DL H70 AC-DL H719 C/HQ1-DL H719 AC/HQ-DL H70 C/HQ1-DL H70 AC/HQ1-DL |
H719-DL:20~220mm H70-DL:30~220mm H719/HQ1-DL:20~220mm H70/HQ1-DL:30~220mm |
Super speed (higher than H and HS series); High rigidity; Suit for direct lubrication |
|
High speed sealed angular contact ball bearing(incl. hybrid ball bearing) |
B719 C-2RZ B719 AC-2RZ B70 C-2RZ B70 AC-2RZ B70 C-2RZ/HQ1 B719 AC-2RZ/HQ1 B70 C-2RZ/HQ1 B70 AC-2RZ/HQ1 |
B719-2RZ:10~220mm B70-2RZ:10~220mm B719-2RZ /HQ1:10~220mm B70-2RZ /HQ1:10~220mm |
High speed; High rigidity; Grease lubrication |
|
High speed bearings for inner diameter grinding spindles (incl. hybrid ball bearing) |
B70 C B70 C/HQ1 |
B70 C:10~60mm B70 C /HQ1:10~60mm |
Super speed; High rigidity; Suit for oil mist lubrication |
3. Application:
•Machine tool spindle
•high-frequency motor
•Robot technology
•gas turbine
•centrifuge
•small-size automobile front wheels
•differential pinion shaft
4. Advantages:
As an important type of machine tool bearing, angular contact ball bearing has the following advantages:
The chamfer arc radius of rings is reasonable, which is not only convenient to install, but also guaranteed to improve the installation precision and reduce the risk of the related parts being bumped;
•The speed performance is outstanding
•Unique heat treatment process allows products to achieve the best dimensional stability and rigidity, so as to reduce wear and tear;
•Multiple preload levels can help to meet different requirements for speed and system stiffness, which is more reasonable to select and use the levels.
5. Preload
The preload is a measure of the rigidity inside the bearing.All Super Precision Angular Contact Ball Bearings must run with some preload. It is important to note that as preload is increased the rigidity will be higher but the speed and life will reduce.
There are four standard preload options available from which offer a large range of rigidity and interchangeability.
5.Precision Class
Precision grade determines the dimensional accuracy and run out of the bearing. The precision can be increased with no side effects.
6.Arrangements
Super Precision Angular Contact Ball Bearings are arranged in application in order to handle loads from multiple directions. The load travels through the lines of the contact angles, normally to form an O arrangement, back to back, or X arrangement, face to face.
To account for the loadings in an application, multiple bearings will be used in an assembly normally (single), (duplex). (triplex), (quadplex), etc.
If a bearing is labelled as Universal then it means it can be fitted into any of the above arrangements.
7.Limiting Speeds
The limiting speeds listed in the Bearing Dimensional Tables are guideline values. They are based on a single bearing that is lightly preloaded by means of a spring and subjected to relatively light loads with good heat dissipation.
The limiting speeds with grease lubrication are determined using high quality grease in appropriate amounts. Those listed for oil lubrication are based on the use of oil air (or oil mist) lubrication. In situations where the lubricating oil is used as a means to remove heat, higher speed can be achieved, however a large amount of oil must be pressure fed through the bearing, so there is a significant loss of power.
8.Speed Factors
The limiting speed of a matched bearing set operating under position preload conditions is calculated by multiplying the limiting speed of a single bearing in the set by the appropriate adjustment factor listed.
In this table, preloads mean the preload values after the bearing has been attached to the spindle. Preload values after the bearing has been mounted on the spindle will change as a result of the shaft fit requirements of high speed operation and spacer deformation due to tightening force. In such case, particular in high speed applications, it is necessary to adjust the spacer lengths relative to each other in order to compensate for the changes in preload after bearing mounting.
Standard Series of High Precision Angular Contact Ball Bearings
Basic series precision angular contact ball bearings that meets ISO standards.
Features:
1.Montons S steel, a long life bearing steel, is used as the standard material.
2.The 70 and 79 series are sealed with a grease life that has been improved by one and half times.
3.Two types of cages are available.
Ultra High-Speed Angular Contact Ball Bearings
This series developed with the best of material, evaluation, and analysis technologies, of whichis proud. This is highly functional series for machine tool. In addition, the sealed type of this series, which offers longer service life and shows excellent environmental friendliness is available.
Features:
1.Reduces heat generation and achieves high-speed rotation
2.We offers long service life for use in high-speed applications.
3.Wide lineup to meet various applications is achieved.
4.Grease life of the selaed type has been extended.
BAR BTR High-Speed Angular Contact Thrust Ball Bearings
A Robust series of angular contact ball bearings for sustaining axial loads that achieves high-speed and high rigidity performance.
Features:
1.The BTR series has a contact angle of 40° that features both high thrust rigidity and low heat generation properties.
2.The BAR series has a contact angle of 30° that focuses on high-speed performance in comparison to the BTR series.
TAC Series of Highly Rigid Angular Contact Thrust Ball Bearings
The TAC series of angular contact ball bearings is used to sustain axial loads and is focused on high rigidity.
Features:
A contact angle of 50° that focuses on rigidity, and perfect for highly rigid spindles that operated under heavy-duty cutting applications.
Spindle ball bearings are single row angular contact ball bearings (separable ball bearings) with a nominal contact angle of 15° or 25°. They can be subjected to both radial and (in one direction) axial loads. The direction of the axial load carrying capacity is shown by a marking on the outer ring.
Spindle ball bearings are characterized by the following properties:
Manufacture in grade P4 (or ABEC7) or better
Rings generally made of corrosion-resistant SV30 high-grade steel
Steel or ceramic balls available for all types
Machined solid retainer of fiber reinforced phenolic resin or special materials, for applications involving higher temperatures
15° (C) or 25° (E) contact angle as a standard
Optionally, bearings can be paired with three predefined preload classes (L, M, S) or individual pre-load
Oil or grease lubrication
Open and closed versions available
Assembly, lubrication and packaging pursuant to cleanroom grade 10,000
Open spindle ball bearings:
Standard version with large balls for optimum utilization of the bearing interior and solid retainer for high bearing capacity.
The outer ring has one shoulder only. The increased height of the snap feature prevents bearing collapse.
Solid retainer guided on outer ring with low cross-section, particularly well suited for oil injection lubrication.
Closed spindle ball bearings:
The non-contact shields do not cause any additional friction torque
The standard shields made of Viton with metal stiffener offer excellent temperature and media resistance
Very narrow sealing gap for high dust protection
Recommended for grease lubrication, increases the longer service life
Same outer dimensions as open spindle bearings
This design requires often smaller balls, resulting in a lower bearing capacity but higher axial stiffness and speed limit (usually noted by index letter after the basic type in the part number).
Also available without closure as high-speed version
Handling:
Leave the bearing in its air-tight package until you are ready to start the assembly.
Ensure extreme cleanliness at the work area.
Avoid shocks and impacts.
Axial load must only act on spindle bearings as indicated by the marks on the outer ring.
Use suitable assembly tools to ensure that no assembly forces can be transferred through the balls.
Duplex bearings of pairing types -1 (DB), -2 (DF), -3 (DT) are always packed in pairs and can only be assembled in the specified arrangement with the other bearing in the package.
Universally matched bearings can be freely paired with each other, i.e. you may combine bearings from different packages or lots. These bearings may be assembled in any arrangement.
Before start of operation, allow the bearing to run in at high speed.
Due to their internal design, angular contact ball bearings can withstand high radialaxial loads and reach high speeds. They are asymmetrical for manufacturing reasons and can withstand unidirectional axial loads only. Angular bearings are usually mounted in a group of two or more opposed preloaded units with rigid or elastic spacers. Typically, the inner and outer raceways and balls are made of chrome steel. Where operating conditions are severe, bearings may have ceramic balls creating a hybrid bearing.
Angular Contact Ball Bearing Series
Many angular contact bearing manufacturers have three or more dimensional series to accommodate higher speeds or higher loads than “standard.” In particular, the most common series names are:
ISO 18 Series - highest speed, lowest load bearings
ISO 19 Series - second highest speed, with the second lowest load bearings
ISO 10 Series - highest load, second lowest speed bearings
ISO 02 Series - highest load, lowest speed bearings
ISO Equivalents To Monton's Series Designations
Many times, manufacturers have further separated the ISO dimensional classes by adding a higher speed variant with the same dimensions. The following table summarizes AST's product offerings:
ISO Series | AST Designation |
---|---|
ISO 18 | 718 Series Angular Contact Bearings |
ISO 19 | 719 Series Angular Contact Bearings |
ISO 19 (high speed) | H719 Series Angular Contact Bearings |
ISO 10 | 70 Series Angular Contact Bearings |
ISO 10 (high speed) | H70 Series Angular Contact Bearings |
ISO 10 (high load) | B70 Series Angular Contact Bearings |
ISO 02 | 72 Series Angular Contact Bearings |
High precision angular contact ball bearings have been designed for all rolling bearing applications that make great demands on reliability, stiffness, speed capability and running accuracy; the bearings may be used as single bearings or as bearing combinations.
The many different types available allow spindle manufacturers across different sectors of industry as well as special purpose mechanical engineering firms to optimise their spindles by focusing on the criteria that are most important to them. Technology and economic efficiency thus meet to form a winning combination.
As the bearing of your choice will depend on the application you are designing,We offers a variety of bearing series with many differentversions, sizes and diverse design characteristics. This wide range of products enables the bearing user to achieve a higher performance at a lower cost. Angular contact ball bearings for example can be supplied with contact angles of 15°, 25°, 30°, 40°and 60° and with various rolling element diameters as well as with rolling elements made of steel or ceramics. This makes them a very popular choice. Our product and services range also includes the possibility of choosing an ATCoat thin dense chromium coating for special types of application.
High precision bearings that are grease lubricated in our factory and additionally sealed with contact or non contact seals are maintenance free, meaning that for “life lubrication” becomes a reality. This fact contributes both to simpler, customer friendly designs and to simpler assembly.
Arrangements, assorting of Precision Angular Contact Ball Bearings
Arrangements, advantages of bearing sets, mounting according to different needs spindle bearings are used in various arrangements.
Sealed Spindle Bearings
Thanks to sealed spindle bearings, it has been possible to convert an even wider field of applications to grease lubrication. These bearings are filled with heavy duty grease Arcanol L75 and fitted with noncontact seals at both sides.
Based on the experiences gained with sealed high speed spindle bearings, other spindle bearing series were also designed in a sealed version so that the following advantages
• ready-to-mount
• filled with optimum grease in the appropriate quantity
• protected against contamination are now available throughout the entire bearing range
DIRECT LUBE Bearings
Where grease lubrication meets its limits, DIRECT LUBE bearings complement the spindle bearing range in a virtually ideal way.
DIRECT LUBE bearings ensure reliable lubricant feed very close to the point of contact. This is achieved by a circumferential groove and radial supply holes. Integral precision O-rings seal the bearing against the spindle housing.
Hybrid Bearings
Hybrid bearings rings of steel and balls of ceramic material are most commonly used for spindle bearings. Originally only to be found in the high speed sector, they are meanwhile also used with significantly lower speeds. The reasons for this trend are
• their robustness and reliability
• their significantly extended service life
Hybrid bearings were an important prerequisite for the extended use of grease lubrication. In this connection they are a further factor for the reduction of system cost.