The main shaft bearing is an important part of an aero engine. If the main shaft bearing of an aero engine fails, it will directly affect the normal use of the engine. It can be seen that if the main shaft bearing fails, the consequences will be disastrous. This is why Eric Bearing Limited mainly explains the following IKO spindle bearing slippage faults.
1. IKO main bearing bearing sliding fault is mainly manifested in the location (typical location)
Example: The working surface of the double half inner ring angular contact ball bearing has slippage failure
Slippage generally occurs on a half-ring raceway of a double-half ring, and there is obvious tailing phenomenon, and one third of the spherical surface of the rolling element of the faulty bearing is discolored. Of course, there are also wide and narrow half-rings that have slippage at the same time, and there are also cases where the steel ball changes color and the inner ring does not slip.
The main cause of IKO roller bearing skid injury is the light weight of the rotor, which does not form sufficient radial load on the bearing; the main cause of ball bearing skid injury is the change of the axial load. In addition, when the movement resistance of the rolling elements and the cage is too large, the slipping and rubbing failure will occur.
2. IKO spindle bearing sliding fault factors
(1) Slip caused by insufficient axial load
When the axial load of the IKO bearing is insufficient, the radial force acts on the bearing and is transmitted to the steel ball to prevent it from forming an effective contact angle. The steel ball is in contact with the two half inner rings at the same time, forming multi-point contact. Then there is a slipping fault. IKO NA 4906 bearings online , pls click here :
(2) Multi-point contact caused by insufficient radial clearance
The inner ring of the IKO bearing has a peach-shaped groove structure. In the case of insufficient radial clearance, it will cause the surface of the steel ball and the groove surface to slip and scratch.
(3) Slip caused by the spin of the steel ball
In a ball bearing that rotates at high speed and bears a certain axial load, a centrifugal force that deviates from the center of the ring and is distributed in the radial direction will be generated, which changes the force of the IKO bearing. Under the action of centrifugal force, the force of the steel ball on the outer ring channel is greatly increased, while at the same time the force between the steel ball and the inner ring channel is reduced. The change of the force on the inner and outer ring channels will affect the change of the contact angle between the steel ball and the inner and outer rings, resulting in a smaller contact angle of the outer ring and a larger contact angle of the inner ring.
In the case of a certain axial load, the higher the speed of the bearing, the greater the difference between the contact angles of the inner and outer rings. If the contact angle of the inner and outer ring is very different, it will affect the friction state in the bearing.
As the contact angle between the ball and the outer ring channel becomes smaller, the movement mode is close to a pure rolling state; the contact angle on the inner ring channel becomes larger, so that the steel ball bears an additional moment, namely the gyro moment, in addition to the rolling moment. The torque will cause the steel ball to spin motion on the inner ring channel. The direction of rotation is to rotate around the axis connecting the steel ball and the inner ring contact point and the center point of the steel ball. The direction of self-rotation makes the contact pair appear sliding friction, and the result The surface of the steel ball in contact with the inner ring channel is caused to wear by sliding, and the size of the sliding area is related to the contact angle at that time.
(4) Slip caused by excessive axial load
When the three-point contact ball bearing is working, the steel ball is in contact with the bearing inner ring, and there is a residual gap with the non bearing inner ring. When the residual gap is zero or negative, there will be multiple contacts, which will cause slippage failure.