Bearing arrangement in horizontal overhung centrifugal pumps OH2

[Param684]

Hello Sir / Madam,

Could anyone please elaborate on the design basis on which the thrust bearings in an OH2 pump could be located closer to the impeller and the radial bearing farthest from the impeller?

For clarity, please refer to the arrangement in fig2.2c on page11 of the link below. As you know, the bearing arrangement in most pumps are per fig 2.2d. Hence my above question.

https://cdn.skfmediahub.skf.com/api...edium/0901d19680054a8a_pdf_preview_medium.pdf

Thanks in advance for your time.

 

[TugboatEng]

From your images the second case has a larger diameter impeller which implies it operates at a higher pressure with more thrust. In a heavily loaded case it makes sense to put the bearings closer to the load.