First off, it depends on the type of motor bearings installed in your motor. Three potential types of bearings can be installed on the motor shaft. Depending on the specific bearing installed, the answer can differ. The three types of bearings are listed below:
As you can see in the picture above, the ball-bearings are exposed on both sides. This is what you would call an open bearing. There is no cover on either side of the bearing, leaving both sides exposed – or open. Hence why they call them open bearings. These bearings should be greased ever so often and according to manufacturer guidelines. General rule is a dab here and then can’t hurt. However, you don’t want to over grease them – which can lead to motor issues.
Sealed bearings are exactly as they sound – sealed. As you can see from the picture above, the ball-bearings are sealed from the outside environment. Due to the seal, these types of bearings are considered “lubricated for lifetime of the bearing”. In short, you do not have to grease these type of motor bearings.
Shielded bearings are a combination of both open & sealed. These bearings have a “cover” or shield on each side which can be removed to expose the internal ball-bearings. When installing these types of bearings on a motor, you would remove the shield exposed to the grease fitting to allow for routine greasing. According to the manufacturer’s specifications, these should also be greased, but remember not to grease if both sides have shields on. This could cause the shield to impress on the internal bearings and fail.
If you would like to learn more regarding motor bearing greasing or a quote to have your motor bearings replaced, please email firstname.lastname@example.org or call us at (781) 932-3030, and we will be happy to answer any questions!