NTN Self Aligning Ball Bearings

These ball bearings have a spherical surface with a point at which the center of the outer ring track surface matches the center of the bearing, and the inner ring has a two-row track groove.

Self-aligning ball bearings are particularly suitable for misalignment applications where mounting accuracy is difficult to guarantee or where shaft deflection may cause misalignment.

The balls, cage, and inner ring are able to tilt freely to a degree with respect to the outer ring, and rotate. As such, misalignment caused by processing errors in the axis or housing, or by mounting of the bearing, is automatically corrected.

However, as the capacity to bear axial loads is not so great, the bearings are not suited to locations with large axial loads.

The bearings are often used in applications such as drive shafts, as mounting and un-mounting are easy if an adapter is used for bearings with tapered bore calibers.

Features and Benefits:

• High quality steel - Ultra clean steel helps extend bearing life extended up to 80%
• Pressed steel and polyamide cages available
• Advanced Grease Technology - Lubricants that can extend grease life and performance
• High grade balls - Smooth and quiet operation even at high speeds
• Super Finished Raceways - Refined to minimize noise and improve lubricant life and distribution

Can they interchange with standard ball bearing assemblies?

Depending on the series, most self-aligning bearings can be interchanged with standard ball bearing assemblies. (6200 and 6300 have direct interchanges with the 1200 and 1300 series). However, if this is not possible, the self-aligning bearing may be wider or can have a tapered bore

Self-aligning Ball Bearing vs Basic Ball Bearing

Self-aligning ball bearings are usually composed of an outer ring with a spherical raceway, a double raceway inner ring, two rows of steel balls and a cage. The inner ring with two rows of steel balls and the cage can swing at a certain angle along the outer ring spherical raceway. Compared with ordinary ball bearings, this allows self-aligning linear ball bearings to work normally even when the shaft is slightly misaligned (approximately 0.07 to 0.12 radian (4 to 7 degrees) under normal loads) with respect to the bearing housing. Therefore, it is especially suitable for the application of misalignment caused by component structure that is difficult to ensure installation accuracy or shaft deflection, and solves the problem that ordinary ball bearings need to be accurately aligned, and can be used in many scenes that are difficult to accurately align. However, under the premise of not achieving precise alignment, although self-aligning ball bearings can operate normally, they cannot adapt to excessively fast working speeds. Therefore, compared with ordinary ball bearings, self-aligning ball bearings are usually used in occasions where the speed is not high, the requirements for noise and vibration are not high, and the installing and the un-installing are difficult.

Choice and Installation of Self-aligning Ball Bearing

We usually choose the bearing products according to the specific application, like the load, speed and space constraints, etc. But when choosing a self-aligning ball bearing, we not only need to choose it according to the load, speed and space constraints of the application scenario, but also need to consider the amount of misalignment and shaft deflection. The basic design of a self-aligning ball bearing has a cylindrical hole, or in some size ranges, a tapered hole. We usually will choose to heat the bearing before installing it. However, if the bearing needs to be cold-mounted in special circumstances, the installation tool must be a special sleeve tool to ensure that the installation force will not be transmitted through the steel ball during the installation process, so that the steel balls and raceways will not be damaged during the installation process. If the bearing has a tapered hole, it can also be installed using a two-step hydraulic drive method.