Multistage centrifugal pumps are equipped with both rolling bearings and shaft bearings
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Does a multi-stage centrifugal pump come equipped with both rolling bearings and shaft bearings? What is the intention behind this design?
The normal configuration uses shaft bearings for support, while rolling bearings are used for the thrust at the non-driving end. Is there any reason to question this?
The rolling bearing doesn’t seem to have any positioning device; it’s simply fitted over the shaft.
Please show the image above. . I have seen this situation in small turbines as well
It’s a normal structure; our factory’s high-temperature hot water pumps and high-pressure boiler feed pumps all work in this way
The outer shaft end has locking wires; it mainly bears axial forces, and the outer ring does not need to be fixed.
Generally, high-temperature hot water pumps, boiler feed pumps, and lean methanol pumps all use this type of structure; in API610, it is classified as BB3 type.
Bushing bearings can only control axial forces in the radial direction, while rolling bearings can control both axial and radial forces (such as deep groove ball bearings).
In multi-stage centrifugal pumps, a balance disk is generally used to balance most of the axial force, with the remaining axial force being taken care of by thrust bearings, which are typically paired angular contact ball bearings; the shaft bearings, on the other hand, only bear radial forces.
The shaft of a multi-stage pump has a certain offset; positioning is achieved through the balance disk, while the bearings serve only a supporting role. The bearing cannot be locked.
It’s different from what was said upstairs. So, like sliding bearings, do rolling bearings also serve a supporting function?