×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Sliding Thrust Bearing Internals

Sliding Thrust Bearing Internals

Sliding Thrust Bearing Internals

(OP)
How the total weight of the Vertical Pump shafts is supported by sliding thrust bearing on the top.Can anybody explain the internals of the bearing where it exactly supports the shaft and How shaft is lifted during its impeller clearance adjustment in pumps which have rigid coupling and sliding thrust bearing? Is there any adjustment thread or nut to facilitate the impeller lift? If so how it is measured?

RE: Sliding Thrust Bearing Internals

Our largest vertical pumps have two methods of dealing with lift and thrust. In all cases, the thrust of the pump is supported by the thrust bearing in the motor. All of our motors use a tapered roller bearing for thrust bearing.

In our deep well pumps, the motor thrust bearing is on the top. A threaded nut lifts the shaft. The lift procedure specifies the lift based on thread pitch and nut rotation angle. Once the shaft is lifted by the specified amount, the nut is locked.

For our largest cooling tower pumps, the motor thrust bearing is on the bottom. The adjustment is at the rigid coupling. The threaded nut on the motor is shimmed by the amount of lift specified. The nut is rotated to lift the shaft until it turns free. Then the shim is removed which lifts the shaft by the thickness of the shim.

The lift setting is specified by the pump manmanufacturer. Lift is based on impeller configuration, wear ring configuration, rotor weight, shaft length, process temperature and pressure.

Johnny Pellin

RE: Sliding Thrust Bearing Internals

Quote:

How the total weight of the Vertical Pump shafts is supported by sliding thrust bearing on the top.
Assuming the machine has a rigid coupling, then it acts like one long shaft. If not other thrust bearings in the machine (other bearings allow float), the thrust bearing will take the thrust.

Quote:

Can anybody explain the internals of the bearing where it exactly supports the shaft
Sliding thrust bearing on a motor would be in an oil reservoir at the top of the motor. The thrust pads pivote to form a hydrodynamic oil wedge which is thicker at the leading edge than the trailing edge. Kingsbury style have a system of equalizing pads / pins / spacers below the thrust pads which act to ensure load is shared (if you push down on one pad the equalizing pads cause the adjacent pads to move up). Other styles rely on fine adjustment of pad height to assure load sharing (I never liked this). You should have oil level indication and temperature indication, along with periodic oil sampling and periodic vib monitoring.

Quote:

How shaft is lifted during its impeller clearance adjustment in pumps which have rigid coupling and sliding thrust bearing? Is there any adjustment thread or nut to facilitate the impeller lift? If so how it is measured?
On the rigid vertical pump couplings I have seen, the coupling includes an adjustment nut above the pump side hub. The lift is measured as distance between pump resting on bottom and pump in coupled position. Measured on the pump hub (which remains stationary with respect to shaft… only the nut above it is adjusted).

=====================================
(2B)+(2B)' ?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources