Spherical roller thrust bearings

Spherical roller thrust bearings are able to carry high axial load. Because of their construction with spherical raceways and transmission of load at a certain angle they can carry radial load as well. They are dismountable which allows simpler installation of individual rings into the arrangement.

Design of the individual parts of the spherical roller thrust bearings allows in operation certain mutual misalignment of the rings against each other. In this way the spherical roller thrust bearings are able to eliminate certain deflection of the connecting parts.

Spherical roller thrust bearings have a great number of asymmetrical spherical rollers with a good conformity to the raceway and therefore they are able to carry high axial load.

Spherical roller thrust bearings can be applied in arrangements with high demands for load forces transfer, e.g. shaping machines, cranes, ship’s shaft, mining machines, etc.

Spherical roller thrust bearings


 

Design specification

Main dimensions

The main dimensions of double row spherical roller bearings specified in the dimension tables are in accordance with the international standards ISO 104.

Design

Spherical roller thrust bearings are commonly manufactured with brass cage guided by a sleeve held in the shaft washer bore. Designation of these bearings is „MC” Another manufactured design is spherical roller thrust bearing with pressed window-type steel cage. Their designation is „EJ”.

Tolerance

Spherical roller thrust bearings are produced in standard P0 tolerance class. Production of bearings with a higher tolerance class should be discussed with the manufacturer in advance.

Influence of the operating temperature

Spherical roller thrust bearings undergo special heat treatment, which enables their application at high temperatures up to 200°C without any change of dimensions.

Misalignment

Because of their design spherical roller thrust bearings allow mutual misalignment, i.e. at common operating conditions (Pa ≤ 0,1.Ca) they are able to accommodate the misalignment of the shaft and housing without affecting their correct function. Permitted misalignment is stated in the table:

Permitted MisalignmentBearing Type
292XX
2°30’293XX
294XX

Equivalent dynamic load

In dependence on the influence of the bearing arrangements run-outs and its elimination by the mutual movement of the rings and if Fr ≤ 0,55.Fa then:

Pa = Fa + 1,2.Fr

Pa = 0,88.(Fa + 1,2.Fr)

– when run-outs in the bearing arrangement affect the load distribution in the bearing

– when run-outs in the bearing arrangement do not affect the load distribution in the bearing


where:
Pea – equivalent dynamic load of the bearing (N)
Fa – radial load of the bearing (N)
Fr – axial load of the bearing (N)

If Fr ≥ 0,55.Fa, the ZVL SLOVAKIA engineering department should be contacted.

Equivalent static load

Axial load is, if Fr ≤ 0,55.Fa:

Poa = Fa + 2,7.Fr

where:
Poa – equivalent static load of the bearing (N)
Fa – radial load of the bearing (N)
Fr – axial load of the bearing (N)

If Fr ≥ 0,55.Fa, the ZVL SLOVAKIA engineering department should be contacted.

Minimum axial loading

At the operation of axial bearing a risk of roller bodies slippage between the orbits of rings is registered due to the presence of centrifugal forces and friction of lubrication and so that the possibility of damage for roller bodies or orbits, respectively. Therefore, a minimal loading must act on the bearing. Its size can be derived from following formula:

Famin = 0,00125.Co

where:
Famin – minimal loading (kN)
Co – static load capacity (kN)