How do deep groove ball bearings handle misalignment between shafts and housings?

Deep groove ball bearings can tolerate a small amount of angular misalignment, between 2 to 3 degrees, without significant issues. This tolerance is due to the ball's ability to move slightly within the raceway during rotation, which helps accommodate minor angular misalignments between the shaft and housing. However, deep groove ball bearings are not designed to handle larger misalignments. As the misalignment exceeds the tolerance, the bearing may start to experience undue stress, resulting in uneven load distribution, increased friction, and excessive wear.

Deep groove ball bearings are primarily designed to handle radial loads, with the added benefit of supporting axial loads in both directions. When misalignment occurs, even within the allowable range, the load distribution across the bearing becomes uneven. This can cause localized stresses that compromise the bearing's performance. Although deep groove ball bearings can accommodate light misalignment, any significant axial load resulting from misalignment can place excessive strain on the bearing's inner and outer raceways, reducing their capacity to handle both radial and axial loads effectively. Over time, the combination of misalignment and load can lead to degradation of the rolling elements and raceway surfaces.

The presence of misalignment can significantly reduce the service life of a deep groove ball bearing. Misalignment causes the rolling elements to travel along irregular paths within the raceway, which leads to uneven wear. This irregular wear results in increased friction, which in turn generates heat and accelerates the degradation of the bearing surfaces. Prolonged misalignment increases the risk of "ball skidding," where the balls do not roll smoothly along the raceway but instead slip, which results in even greater wear and surface damage. The accumulation of heat and wear also makes the bearing more susceptible to corrosion, pitting, and surface cracking. The result is a reduced operational life and possible premature failure of the bearing.

Misalignment between the shaft and housing can also contribute to radial and axial runout, further exacerbating bearing performance issues. Radial runout refers to the variation in the shaft's radial position relative to the bearing's centerline, which results in uneven load distribution. Similarly, axial runout refers to any axial displacement of the shaft, which can cause uneven axial loads on the bearing. Runout caused by misalignment can create oscillations and vibrations within the system, which can lead to noise and further increase stress on the bearing. These vibrations not only reduce the efficiency of the bearing but also contribute to mechanical wear, making the system less reliable and more prone to failure.

While deep groove ball bearings can handle minor misalignment, they are not ideal for applications where misalignment is expected to be a frequent or significant issue. In such cases, bearings specifically designed to accommodate misalignment may be more suitable. For example, self-aligning ball bearings are designed with two rows of balls and an inner ring that is spherical, allowing for a greater degree of misalignment—up to around 5 degrees—without affecting performance.

The sealing system within a deep groove ball bearing plays an important role in protecting the bearing from contamination, which can be exacerbated by misalignment. Seals are typically designed to keep out dust, dirt, and moisture, which can accelerate wear and corrosion. However, excessive misalignment can cause the seals to become misaligned or subjected to uneven loading, potentially leading to seal deformation, premature wear, or leakage. If the seals are compromised by misalignment, contaminants can enter the bearing, causing further damage to the rolling elements and raceways.