about hydroelectrical power stations 1

[turkoman]

pls tell me about these parts on turbine and generator

1- pedestal bearing
2-guide bearing
3- thrust bearing

 

[PPC800]

http://www.bearingsindustry.com/aboutbearing.htm

 

[turkoman]

i wonder the functions of them in a hydroelectrical power central

 

[byrdj]

1- pedestal bearing... would be bearing that establishes the radial position of the rotating elements with respect to stationary elements. Pedistal usaually refers to the mounting structure for the bearing and could also implie the bearing is also supporting the weight of the rotating element. These would also be called journal bearings

2-guide bearing.., would also be a journal bearing. Guide usually refers to the position of the journal bearing and also implie the journal bearing is not supporting any weight

3- thrust bearing...would be a bearing that establishes tha axial position of the rotation elements with respect to the stationary elements. for a horizonal rotating element the thrust would not support any weight, but would support all the weigh for a vertical rotating element

 

[byrdj]

http://www.scribd.com/doc/5245721/francis-turbine-

 

[turkoman]

what is the difference between pedestal and thrust bearing? both of them supports the turbine in vertical plane? they are enduring the weight ?

 

[turkoman]

i think there is no one who deals with hydroelectrics..

 

[ozmosis]

Maybe you should ask a mechanical engineer, in a mechanical engineering forum; if it's just the bearings you're interested in.

 

[wolf39]

A pedestal bearing is used for horizontal electrical machines. This type of bearing has no other use than carrying the weight of the rotating parts. In some cases a pedestal bearing is additionally equipped with an extra bearing at one end which is limiting the horizontal movement of the complete shaft arrangement (generator rotor plus hydroturbine runner). This type of bearing could be called a "horizontal guide bearing" or even a "horizontal thrust bearing", in case horizontal forces are acting on the shaft. The proper English term may be "journal bearing", I'm not sure.

A guide bearing usually is used for vertical electrical machines. Under ideal conditions (no unbalance forces coming from the rotating parts and no stochastic forces coming from the hydroturbine) this type of bearing does not carry any load. It's bearing pads are just surrounding the shaft, keeping the shaft centered within the guide bearing. In practice, however, guide bearings have to be designed to carry certain radial forces because of rotor unbalance and forces originating from the prime mover (hydroturbine).

A thrust bearing is used for vertical electrical machines, i.e. hydro generators. This type of bearing is carrying not only the weight of the rotating parts (generator rotor plus turbine runner) but also has to be designed to carry the hydraulic thrust originating from the turbine water flow.

Regards

Wolf

http://WWW.HYDROPOWER-CONSULT.COM

 

[turkoman]

cheers thank you mr wolf39 it is kind of you to write all these here...

 

[wolf39]

I forgot to mention that in practice the guide bearing of a vertical machine not only has to carry the load originating from mechanical unbalances and hydroturbine forces. Magnetic unbalances (unequal field pole air gaps, for instance) are also to be considered.

Regards

Wolf

http://WWW.HYDROPOWER-CONSULT.COM