Screw drive bearing arrangements are subjected to requirements that often cannot be optimally fulfilled by the design construction of conventional bearings.

For the design of bearing arrangements for the highly dynamic operating conditions in screw drives that have high accuracy, high load carrying capacity, high rigidity, low friction, are easy to fit and maintenance-free or low-maintenance, there is a wide range of INA and FAG axial angular contact ball bearings. With this product range, solutions can be found to all the technical and economic demands placed on the bearing arrangements of screw drives.

Axial angular contact ball bearings are available as single, double or triple row ready-to-fit units. They are self-retaining and comprise thick-walled, geometrically stable outer rings, ball and cage assemblies and one-piece or two-piece inner rings. In several series, the outer ring has through holes for simple flange mounting to the adjacent construction.

The bearing rings are matched to each other such that a defined preload is achieved when the rings are clamped in place using a precision locknut.

Due to the contact angle of 60°, the bearings can support not only radial forces but high axial forces as well.

Axial angular contact ball bearings ZKLF are screw mounted directly on the adjacent construction or in a radial locating bore, Figure 1 and Figure 2. The cover that would otherwise be required and the associated matching work can therefore be dispensed with.

In order to aid removal of the bearings from a locating bore, the outer ring has a circumferential extraction slot.

Relubrication is facilitated by radial and axial threaded connectors with detachable grub screws.

Axial angular contact ball bearings ZKLF..-2RS-PE correspond to series ZKLF but have a runout tolerance within P5 to DIN 620, less stringent diameter tolerances and the suffix PE. They are used where a lower positional accuracy is acceptable. As a result, the adjacent construction does not need to be as accurate with these bearings.

Relubrication is facilitated by an axial threaded connector. The radial lubrication duct is firmly closed off.

Axial angular contact ball bearings ZKLF..-2RS and ZKLF..-2Z are also available in a heavy series. For the same shaft dia­meter, they have a larger cross-section and thus higher basic load ratings.

Bearings of series ZKLF..-2RS-2AP comprise a matched pair of bearings ZKLF..-2RS, Figure 3. The individual bearings are matched to each other.

Matched bearings have an arrow marking on the outside surface of the outer rings. When the bearings are arranged correctly, the lip seals face outwards. During fitting, the hole pattern of the two bearings must match, not the marking.

Bearings with the suffix 2RS have lip seals and highly effective sealing.

Bearings with the suffix 2Z are sealed using gap seals and are suitable for higher speeds.

The bearings are greased using a lithium soap grease to GA28 and can be lubricated via the lubrication connectors in the outer ring. For the majority of applications, the initial greasing is sufficient for the whole bearing operating life.

Axial angular contact ball bearings ZKLN are mounted­ in a housing bore, Figure 4. The bearing outer ring is axially located by a cover.

Axial angular contact ball bearings ZKLN..-2RS-PE correspond to series ZKLN but have a runout tolerance within P5 to DIN 620, less stringent diameter tolerances and the suffix PE. They are used where a lower positional accuracy is acceptable. As a result, the adjacent construction does not need to be as accurate with these bearings.

Axial angular contact ball bearings ZKLN..-2RS and ZKLN..-2Z are also available in a heavy series. For the same shaft dia­meter, they have a larger cross-section and thus higher basic load ratings.

Bearings of series ZKLN..-2RS-2AP comprise a matched pair of bearings ZKLN..-2RS, Figure 5. The individual bearings are matched to each other.

Matched bearings have an arrow marking on the outside surface of the outer rings. When the bearings are arranged correctly, the lip seals face outwards.

The bearing outer rings are axially clamped by a cover, Figure 5.

Bearings with the suffix 2RS have lip seals and highly effective sealing.

Bearings with the suffix 2Z are sealed using gap seals and are suitable for higher speeds.

The bearings are greased using a lithium soap grease to GA28 and can be lubricated via a lubrication slot and lubrication holes in the outer ring. For the majority of applications, the initial greasing is sufficient for the whole bearing operating life.

Bearings 7602, 7603 and BSB are designed as universal bearings, Figure 6 and Figure 7.

They can be combined in a wide range of sets for different requirements, Figure 7.

Single row axial angular contact ball bearings for matching are bearings of the open basic design. However, some sizes are fitted with seals.

Single row axial angular contact ball bearings of the open basic design are not supplied greased. The designs fitted with seals are greased for life with Arcanol L55.

Angular contact ball bearing units ZKLR are low-cost bearings and therefore particularly economical. They comprise a deep drawn sheet steel housing with an integral matched pair of angular contact ball bearings in an X arrangement, Figure 8. The housing has a Corrotect^® coating and is thus protected against rust. The ball bearings are sealed on both sides by lip seals or gap seals. The bearing assembly is preloaded clearance-free.

The units are particularly easy to fit. They:

• are directly flange mounted, for example on the milled face of the adjacent construction. This eliminates the need for precise, costly fits and additional flange covers for seating and axial location of the bearings
• require no additional parts for location of the bearings in the housing
• reduce errors in fitting due to the smaller number of components compared to conventional solutions
• are self-aligning by means of the screw drive nut during fitting. This effectively eliminates any warping due to misalignment of the bearing seats
• have a defined preload. It is not necessary to preload the bearing during fitting as is usually the case with screw drive bearing arrangements
• require only clearance-free axial location on the threaded spindle.

Bearings with the suffix 2RS have lip seals and highly effective sealing. Bearings with the suffix 2Z are sealed using gap seals and are suitable for higher speeds.

The bearings are greased using a lithium soap grease to DIN 51825–K2N–40.

The units are highly suitable, due to their dimensions and design, for space-saving and simple bearing arrangements in highly dynamic screw drives, for example:

• in inspection and measuring equipment
• in small machine tools
• in medical and laboratory equipment
• in precision engineering and electronic components manufacture
• where complete units will give a simpler bearing arrangement.

Series ZKLFA has a stepped outer ring. It can therefore be screw mounted easily on the adjacent construction, Figure 9. The flange has flattened areas on both sides, so the radial design envelope in the adjacent construction can be kept very small.

Bearings with the suffix 2RS have lip seals and highly effective sealing. Bearings with the suffix 2Z are sealed using gap seals and are suitable for higher speeds.

The bearings are greased using a lithium soap grease to GA28 and can be lubricated via a lubrication groove and lubrication holes in the outer ring. For the majority of applications, the initial greasing is sufficient for the whole bearing operating life.

Axial angular contact ball bearings DKLFA..-2RS have, in addition to two rows of balls­ with a contact angle of 60° in an O arrangement, an extra row of balls, Figure 10. Due to this additional row, the bearings can support higher axial loads in one direction.

Due to the stepped outer ring, the bearings can be easily flange mounted on the adjacent construction. The flange has flattened areas on both sides. As a result, it requires only a small design envelope in the adjacent construction.

In order to make full use of the load carrying capacity of bearings DKLFA..-2RS, their design requires that they are subjected to continuous load in the main load direction. They are therefore used mainly in screw drives with a locating/locating bearing arrangement and tensioned spindles or in vertically arranged screw drive bearing arrangements.

For design of the bearing arrangement, please contact us.

Triple row axial angular contact ball bearings have lip­ seals on both sides.

The bearings are greased using a lithium soap grease to GA28. If necessary, lubrication can be carried out via a threaded­ connector for central lubrication systems on the flange side.

For calculation of relubrication intervals based on a stated load spectrum (speed, load, operating duration, environmental conditions), please contact us.

Sealed axial angular contact ball bearings are suitable for operating temperatures from –30 °C to +120 °C, restricted by the grease, the seal material and the plastic cages in the ball and cage assemblies.

The operating temperature influences the dynamic bearing characteristics. The values given in the dimension table are based on a room temperature of +20 °C.

The axial angular contact ball bearings have plastic cages. The cage design is not indicated in the suffix.

In series 7602, 7603 and BSB, the polyamide cages are indicated by the suffix TVP or T.

Suffixes for the available designs: see table.