Spherical roller thrust bearings

Product Description

NEWORLD spherical roller thrust bearings have specially designed raceways and asymmetrical rollers. The bearings can accommodate axial loads acting in one direction and simultaneously acting radial loads. The load is transmitted between the raceways via the rollers at an angle to the bearing axis, while the flange guides the rollers (fig. 1).

Features and benefits

●  High load carrying capacity

    The large number of rollers, which have an optimum conformity with the washer raceways, enables the 

    bearings to accommodate heavy axial and simultaneously acting radial loads.

●   Accommodate misalignment

     NEWORLD spherical roller thrust bearings are self-aligning and can accommodate misalignment (fig. 2).

●   Separable design

     NEWORLD spherical roller thrust bearings are separable, making it possible to mount and dismount the 

     housing washer separately from the shaft washer and roller and cage assembly. In addition this facilitates 

     maintenance inspections.

●   High speed capability

     The cage designs and the optimum conformity of the rollers with the washer raceways make the 

     bearings suitable for relatively high speeds.

●   Long service life

     The special roller profile reduces edge stresses at the roller/raceway contact.

●   Low friction

     The optimized roller end / flange contact keeps frictional heat at low level, even at high speeds.

●   Optimum contact

     Optimum contact between the rollers and flange means very low internal friction, enabling NEWORLD 

     spherical roller thrust bearings to operate from very slow to very high speeds - up to three times the 

     reference speed under certain conditions. ( Diagram 2 )

●   Highest load ratings

     Spherical roller thrust bearings have the highest load rating density of all thrust bearings, This can 

     considerably reduce machine weight, size and cost ! (diagram 3 )

Bearing designs

Basic design bearings

Depending on their series and size, NEWORLD spherical roller thrust bearings are manufactured to two basic designs (fig 3). Their cage forms a non-separable unit with the shaft washer and rollers.

Bearings with no designation suffix

   ●  example: 29272

   ● are fitted with a machined brass prong-type cage as standard

E design bearings

   ●  are identified by the designation suffix E

   ●  have larger rollers and an optimized internal design for increased load carrying capacity

   ●  are fitted with one of the following cages, depending on bearing size:

       ◌  size ≤ 68 → stamped steel window-type cage

       ◌  size ≥ 72 → machined metal prong-type cage 

Bearing ranges

The standard range of NEWORLD spherical roller thrust bearings starts from a 60 mm bore diameter and goes up to a 1600 mm bore. Large sizes can be supplied on request.

Three bearing series for a wide range of applications

The standard bearings cover an expensive dimension range in the three ISO Dimension Series 292, 293 and 294. They satisfy the important selection criteria.

● load carrying capacity

● rotational speed

● space in the application.

When very high load carrying capacity is required, bearings in the 293 and 294 series are suitable. The small cross section of the 292 series bearings have favourable speed, space and weight characteristics.

Smaller and more cost-effective equipment can be designed for longer bearing service life or higher output as a result of the high combined load carrying capacity of NEWORLD roller thrust bearings.

These bearings cane be operate at high speeds even under load conditions.

cages

Cages

Cages in spherical roller thrust bearings are an integral part of the bearing internal design. All NEWORLD spherical roller thrust bearings contain a strong metal cage. This enables them to tolerate high temperatures and operate with all lubricants.

Temperature limits

The permissible operating temperature for spherical roller thrust bearings can be limited by:

   ●   the dimensional stability of the bearing washers

   ●   the lubricant

Where temperatures outside the permissible range are expected, contact NEWORLD.

Bearing washers

The washers of NEWORLD spherical roller thrust bearings are heat stabilized up to 200 °C (390 °F).

Permissible speed

The speed ratings indicate:

   ●  the reference speed, which enables a quick assessment of the speed capabilities from a thermal 

       frame of reference

   ●  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

Design considerations

Abutment dimensions

The abutment dimensions da min and Da max listed in the data table apply for axial bearing loads Fa ≤ 0,1 C0.

For heavier bearing loads, it may be necessary to support the shaft and housing washers over their entire side faces (da = d1 and Da = D1).

For heavy loads, where P > 0,1 C0, the shaft washer bore must be fully supported by the shaft, preferably by an interference fit. Even the housing washer should be radially supported (fig 4).

For additional information about dimensioning washer supports, contact the NEWORLD application engineering service.

Recessed housing bore for bearings with a stamped steel cage

For bearings fitted with a stamped steel window-type cage, the housing bore must be recessed (fig 5) to prevent the cage from contacting the housing during possible misalignment. NEWORLD recommends the following guideline values for the recess diameter:

   ●  D + 15 mm for bearings with an outside diameter D ≤ 380 mm

   ●  D + 20 mm for bearings with an outside diameter D > 380 mm

Lubrication

Axial clearance in bearing arrangements

NEWORLD spherical roller thrust bearings in face-to-face or back-to-back arrangements should be preloaded. However, at the relatively low speeds shown within the green area in diagram 1, the application can be designed to operate with a small axial clearance. 

For these applications, bearings with a modified shaft washer (designation suffix VU029) should be used. Small axial clearance enables simple and cost-effective bearing arrangements to be used, e.g. for horizontal shaft applications at relatively low speeds, as no external preload is necessary.

For additional information about bearing arrangements with axial clearance, contact the NEWORLD application engineering service.

Lubrication

Pumping effect in oil lubricated applications

The internal design of spherical roller thrust bearings creates a pumping action, which produces a flow from the small to the large roller end face, that can be taken advantage of in oil lubricated applications. This pumping action occurs in applications where the shaft is vertical or horizontal (fig 6) and should be considered when selecting the type of lubricant and sealing arrangement.

For bearings with a machined cage used in high-speed applications, NEWORLD recommends the oil injection lubrication method (fig 7 ).

For additional information about lubricating spherical roller thrust bearings, contact the NEWORLD application engineering service.

Mounting

NEWORLD spherical roller thrust bearings are separable, making it possible to mount and dismount the housing washer separately from the shaft washer and roller and cage assembly.

Where a spherical roller thrust bearing with a machined metal cage is to be replaced by an E design bearing with a stamped steel window-type cage, and axial forces are transmitted via the cage guiding sleeve, a spacer ring must be inserted between the shaft abutment and the shaft washer (fig 8 ).

Application

Application：

● Metalworking machinery

● Plastics

● Marine

● Industrial gearboxes

● Pulp & paper

● Material handling

● Fluid machinery

● Mining & construction equipment

● Gearboxes

● Extruders and injection molding machines

● Marine propulsion machinery

● Cranes and bridges

● Hydroelectric generators

● Vertical motors

● Propeller axle of vessels

● Tower cranes and 

● Squeezing presses