Common forms of bearing fretting damage

Common forms of bearing fretting damage. In fact, the fretting state of precision bearings is very complex. Usually, according to the simplified plane contact model, according to different relative motion directions, fretting can be divided into four basic motion modes: tangential motion, radial motion, rolling fretting, and torsional fretting.
In fact, the latter three types of fretting often occur or appear in combination of two or more fretting modes. There are three main ways in which fretting damages precision bearings: bearing fretting wear, bearing fretting fatigue, and bearing fretting corrosion. Among them, precision bearing fretting wear is caused by the relative displacement of the contact surface caused by external vibration, and the contact parts bear a large amount of local contact load, which leads to wear of the steel balls and raceways in the precision bearings.
Precision bearing fretting fatigue refers to the fretting caused by the fatigue alternating stress of the precision bearing, which leads to damage to the contact surface of the precision bearing. Bearing fretting corrosion refers to the damage to the contact surface of the precision bearing caused by the use of precision bearings in environments such as rainwater and corrosive gases under the action of corrosive media. After the angular contact ball bearing bears the normal alternating load, the inner and outer precision bearing inner and outer ring raceways leave circular pit-shaped micro-motion damage of "pseudo-Schneider indentation".
The micro-motion wear on the outer ring slows down with the increase of load, increases with the increase of swing angle, and slows down with the increase of the number of cycles. The spherical bearing has micro-motion wear during movement, which leads to the loosening or inaccurate positioning of the robot arm, thereby reducing the quality and service life of the product.