Shaft Straightness Tolerance

LabOwl · Jun 22, 2003

Hi
Could anyone please help me with straightness tolerances that apply to pump shafts. I have a shaft (length = 2875mm, diameter 158mm stepping down to approx 130mm) for a cantilever pump and would like to know what straightness tolerance should be used to ascertain whether it needs to be reconditioned/replaced or reused.
Any direct assistance or links which might provide the information would be appreciated.
Thanks in advance

sprintcar · Jun 23, 2003

You should ask the equipment manufacturer for their exact specs. Any runout on either end will cause vibration, which can reduce bearing and seal life. Typically on a shaft that size you should look for TIR of 0.002" (0.05mm) on the critical diameters. Measure bearing fit diameters first to make sure they were not damaged when removing bearings. Set the bearing fit diameters on rollers and check the shaft from there: Drive end coupling diameter, impeller end at the shoulder, seal area and center between the bearings. Checking the shaft with the bearings installed can be misleading due to internal bearing clearance.
Hope this helps you.

Keep the wheels on the ground
Bob
showshine@aol.com

Kailee · Jun 23, 2003

LabOwl,
We use 0.0005"/ft. as tolerance for straightness.
As long as the bearing fits are within tolerance, shafts may be straightened and reused.

Hope this helps!

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Shaft Straightness Tolerance

LabOwl

Mechanical

sprintcar

Mechanical

Kailee

Mechanical

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