I’m seeking help from everyone regarding a bearing issue
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It’s a bearing from a certain manufacturer, model qj3145n2ma. In this model, the “N2” designation indicates that there are two positioning grooves on the side of the outer ring, as shown in the diagram below. It is a four-point contact bearing; so, should those two grooves at 180 degrees be used for positioning?
It is necessary to secure it, as there is usually a certain gap between the outer ring of this type of bearing and the bearing housing. This type of bearing is primarily designed to withstand axial forces; therefore, it is essential to secure the positioning groove in order to prevent the outer ring from rotating and wearing out.
It needs to be fixed in place; angular contact ball bearings are generally used in equipment that is subject to significant axial forces, such as the screw compressors in refrigeration units. If not secured properly, the outer ring of the bearing will move, leading to mechanical wear. Moreover, as it moves, the axial displacement between the inner ring of the bearing and the rotor also changes, which accelerates the damage to the bearing~
But it seems there’s no protrusion on the outer edge of the card; I don’t understand it
The screw compressors in our company are in the same situation; there is no protrusion at the bearing installation location to hold the outer ring of the bearing in place. Both the male and female rotors are slotted bearings
The bearing is a standard bearing that has been further processed; this is a common tactic used to keep technical details secret. The two grooves are used for positioning during the secondary processing. If positioning relied on keyways, the bearing would vibrate severely, and the inner ring is likely to slip out of place once it starts rotating
Another possibility is that the bearing has stop grooves, but the equipment doesn’t require them; a press-fit fit is sufficient, so it’s possible that the wrong bearing was chosen
It’s the same inside the unit; even if someone from the manufacturer comes, it’s not possible to replace the bearings with other ones
Since the outer ring of the bearing in your equipment does not need to be anti-rotation, as long as the gap between the bearing and the bearing housing is appropriate. Just install it directly. Generally, equipment bearings do not require a anti-rotation design for the outer ring.