The outer spherical bearing is essentially a modification of the deep groove ball bearing. It is characterized by the spherical outer diameter of the outer ring surface, allowing it to be easily accommodated in the corresponding concave spherical surface of the bearing seat, promoting optimal centering. The outer spherical bearing finds its application in situations where simplicity is paramount, such as in agricultural machinery, transportation systems, or construction machinery.
Although outer spherical ball bearings have similar performance to deep groove ball bearings in terms of their basic capabilities, they are generally used under more challenging conditions. In many cases, these bearings are employed in machines that are not particularly precise in terms of mounting position, where the axis of the shaft and seat hole is poorly centered. Additionally, the shaft length can be deflected in larger systems, which can lead to further issues. Furthermore, the bearings themselves may not possess a very high degree of accuracy, and some structures may be rough. Therefore, their actual performance level can be comparable to similar-sized deep groove ball bearings.
An example of such an application is an outer spherical ball bearing with a top wire, which is often used on a through shaft with a large difference in deflection. This type of bearing typically features sealing rings on both sides to prevent dirt from entering, and it is often pre-loaded at the factory.
An adequate amount of lubricant is required for smooth installation of the bearing, and there is no need to clean it beforehand or add any extra lubricant. The top wire screw located on the protruding end of the inner ring of the bearing should be firmly fastened on the shaft to ensure stability. It is important to note that the permissible axial load for the bearing must not exceed 20% of its rated dynamic load.
The outer spherical ball bearing that comes with the eccentric sleeve performs just as well as the version that has a top wire, with the only difference being that the wire is situated on the eccentric sleeve rather than on the inner ring. This type of bearing has a tapered spherical outer spherical ball that has a tapered hole that conforms to a 1:12 taper. It can either be mounted directly onto a tapered shaft or on a shaft without a shoulder by means of a tight bushing. The clearance of the bearing can be fine-tuned to meet specific requirements.
For agricultural machinery, transportation systems, or construction machinery, it is best to use outer spherical bearings when keeping equipment and components simple is necessary. These bearings are ideal for these types of applications.
The primary function of this type of bearing is to withstand both radial and axial loads, with the emphasis being on radial loads. It is not advisable to use this bearing for axial loads on their own. The bearings are available with an inner ring, which includes a complete set of rollers and retainers, as well as an outer ring. However, this type of bearing does not permit axial forces generated by radial loads, by tilting the shaft concerning the housing. The axial spacing of the bearing is crucial for its efficient operation. A small axial clearance can lead to a high temperature rise, while a large axial clearance can result in bearing damage. Therefore, it is essential to check and adjust the axial clearance of the bearing during installation and operation. The bearing rigidity can be increased through pre-loading if necessary.