Adjustment shaft and turning in vertical
hydro-generator unit
Keywords: electric turning; Mechanical turning; Place degree; Hydro-generator unit; Axis; Upper guide bearing; Lower guide bearing; Water bearing; Flange;
Pick to: reduce the error of axial line, reduce the unit operation axis of rotating components unbalance force, is an important work in installation and manufacturing.The existence of all connected components unit manufacture and installation of the error, making the unit the main axis (ie the spindle centerline) and its rotation does not coincide with the center line of the existence of different degrees of tilt or turns.Unit aembly, should be adjusted vertically that mirror surface and unit axis, make the unit set degrees in the range of allowable values and ensure its stable and reliable operation.Unit pendulum degrees size is measured the unit manufacture and installation quality of the main indexes.The purpose is to inspect the car plate tilt and Twists status of the unit axis, through the plate for car measurement data analysis and proceing axis, the bearing, reasonably determine the center position.
A.hydro-generating dish car technology
Car hydro-generating plate can be roughly divided into human turning, machinery turning, electric turning.In practical work according to the units installed model, size, and through the calculated plate for traction, we can develop programs and select the way of turning.
1.Turning conditions
Before turning we should make sure the purpose, second select the way of turning, and then make plane for operation .No matter that turning, hydro-generating unit shall meet the following conditions.
(1) Try to adjust thrust bearing watts of stre, make all tile surface stre
basic even, and make lens board on the horizontal state.Under the on guide
and the nextto ensure that there is at least $4 watts respectively with sliding
axial clearances between is 0.05 mm to control the radial displacement of the
spindle , thereby ensuring the whole hydraulic turbines fluctuation with turning
more easily.
(2) Carefully check the gap of each fixed and rotating parts, should ensure
internal without sundry legacy.Generator rotor clearance circle with a white
cloth with a drawing.Turbine impeller round with feeler checked again.Do lens
board and each tile face clean and already has lubricating conditions.
(3)Other related work ended.Machine Pit drain pump is on, brake
shoes is off.Grinding tungsten watts face when watts with lard or other high
anti-wear lubricant such as \"times force\"; And, after falling in avoiding within
the shortest poible time began to dish car.Have high preure oil jacked up
device of tungsten watts unit disk into high preure oil front should be jacked
up.
(4)After the end of rotor slip ring installation, and brush frame install and
adjust well, next we can do the electric turning .Generator field circuit and
spare field device, stator qualification turning and turning attachment is to
picked well, stator rotor with transmiion conditions
.
2.Traction calculation
The friction of rotating parts compared to thrust watts and lens board is
small, so only consider the latter.We define it as \'F.
\'F-G*f G is the weight of rotational part (KN).The f is friction coefficient
(0.05-0.15)
Friction to center arm refers to turn in lens board average point of friction,
namely the diameter D thrust watts average diameter.So friction torque
M \'= F G.F.D.
Traction F = G*F*D/R*N .R is the radius of the towing point to the rotation
center, N is the number of traction point.
3.Human turning
Usually it is used in small units.On the shaft, or the thrust collar fixed a
turning device.We will achieve the purpose of turning by exerting push pull
unit rotation via leveraged tool,
4.Machinery turning
Mechanical turning is a way of turning which makes the thrust collar or
rotor rotating applied by the mechanical traction .We should also decorate
pulleys and plate frame or turning column at site,.Usually bridge imposes
thetraction.
If the rope tension of bridge machine is greater than the static friction
torque thrust , the hydro-generator unit will turn up slowly.So it comes ture that
the purpose of turning.
5.Electric turning
Electric turning depends on the equipment of electric turning, with the
stator and the rotor windings acceed to DC.we can pa each phase of the
Stator into the current to make the rotor rotating.Next we can achieve the
purpose of turning.When the generator rotor winding with constant dc, general
each pole will produce a constant filed, thus between the air-gap and the stator
core will produce a constant flux.At the same time if the stator single-phase
also ventilation with DC, the phase bar will be clockwise (or anti clockwise)
because of magnetic force.According to the magnetic force and reaction
principle, the rotor will be drived clockwise (or clockwise).If the magnetic
rotation is greater than that of the rotor produced the static friction torque M \',
then the rotor will turn 120 °electric horns.Then we switch the current to
another phase of the stator, rotor going on another 120 ° electric horn.
Three-phase circulation switching, rotor can be continuous rotation.
B.unit axis adjustments
Suspended hydro-generator often adopts the structure of Turbine shaft
and Generator shaft directly connected at present.The umbrella units often
adopt top shaft, hydrogenerator rotor huband turbine shaft linking structure.
If thrust bearing lens board with axis is not vertical axis tilt will appear; if the
combinative position of two flanges and axis is not vertical axis twists will
appear.Axis tilt and tortuous there is large when the unit operating, will appear
larger pendulum degrees.Next there will appear whole periodic mechanical
strength between thrust bearing and guide bearing, maybe it also cause
greater magnetic and hydraulic unbalance force, causing the unit operation is
not in steady state.
1.The method of measuring the axis
1.1Generally high-point of guide bearing acting as the fulcrum, limit by
crane traction thrust collar or rotor rotating machinery plate car or through
electric dish axis measurement method for measuring axis, the general is
above guide limit for fulcrum, through the crane traction thrust head or rotor
rotating machinery plate car or through electric car equipment and the
appointed disk in dc, rotor winding, and aerated stator points of interlinked
rotor rotating electrical control method, on electric dish car in the week of
turning unit spindle stay at 8 prees divide, and be consistent, dish and point
at each axis car to push up, down, left and right, point, big axis should be in an
axial free state, at the same time use the repose upon (X, Y direction) set slip
ring each piece, guide, guide, flange, water under the guide of the place such
as measuring the pendulum degrees batches, values, in general to dish to
check numerical twice.Thus can be obtained for thrust mirror axis is not
perpendicular and flange place for axis proceing twists, turns and provides
the basis.The measured data of disc arrangement, car by drawing feudals put
degrees curve for good, drawn to scale, but the level of axis projection display
feudals put degrees directly maximum azimuth and numerical, convenience in
axis proceing calculation.
1.2Hydro-generator unit of thrust bearing rigid strut, its axis should meet
the \"Specification for installation of hydro-generator unit \" （GB8564-88）.If
axis tilt andtwists exce the range of rating, it is qualified.We must adjust the
axis to the allowed.
1.3Hydro-generator unit of hydraulic pillar type thrust bearings, due to
the hydropower units having automatic adjustment pushing force watts, the
ability to force requirements of unit axis have been relaxed.But for hydraulic
pillar type thrust bearings installation requirements is very strict.By adjusting
stents or base of the thrust, the levelne of the lens board mirror shall not be
more than 0.02 mm/m, and when rfinally the unit rotating components is in unit
center, by the way of Increasing or decreasing reduction of each rotor elastic
oil tank, its biggest compreion value deviation should be no greater than
0.20 mm for qualified.Its use is the so-called \"elastic tutning\" and called fore
each elastic oil tank under the condition of force adjusted qualified, we are
going to move rotational parts of the unit to the center.Then we should fixe the
upper guide bearing, lower guide bearing and water guide on the shaft, on
condition that the axial gap adjusted to 0.05 mm, turning is begun.Edge of
thrust runner collar by the axial swing shall not exceed the range of provisions
in GB8564-88.
2.The axis of treatment
Neither thrust runner collar is vertical to generator axis nor flange winding
are more than prescribed value of theGB-8564-88,and installation, overhaul on
the condition of decompositing the flange, we should revise the axis both in
thrust and flange respectively.If the deal only with thrust runner collar, without
proceing axis in twists, when turning and calculating position of the thrust
runner collar, consideration should be given to decreasing pendulum degrees
of the water guide bearing.
Installating hydro-generator unit, we can also take measures of installation
and decompositing respectively.First execute the tutning of generators.Having
adjustmented generator axis, connect turbine shaft with turbine shaft.Then we
should procee the flange connected position and place a degrees
adjustment to qualified range.Thrust the proceing,generally adopts the
Scraping method ,because it may obtain long time axis constant repairing
effect.Work can be directly done proceing undersurface of thrust (no mat) or
scraping their combination between insulation plate surface.Practice shows
that the former to the latter achieves better results.Flange tortuous proceing,
can adopts the methord of the flange joint surface asked added pad or
scraping the flange joint surface.If scraping proce is correct, no longer
changes appear after treatment generally.Scratch repair to determine the
amount and direction, according to the results drawn from the turning axis of
the horizontal projection obtained, repair scraped surface should be wedge,
the actual steps to form the repair carried out by scraping.Add pad thickne
should be equal to the amount of repair scratch, but the direction is reversed.
3.Axis adjustment
Axis adjustment refers to that unit rotational part center axis adjustmen
qualified.After adjustment, on one hand should make both generator stator
and rotor rotating center are Concentric ,and Turbine rotating center and the
turbine fixed stanch ring in a straight line; On the other hand, we should make
the thrust bearing force equilibrium, and the center of each trustbearing
watts cncentric.Afterwars ,make the unit rotational parts run around the unit
center.Accurate adjustment can not only obviously reduce magnetic
unbalance force of generator and turbine hydraulic imbalance force ,but also
make the vibrationand unit swing amplitude in good degree of standard range
with entirely mechanical force that bearing exerts
There are two kinds of cases of axis adjustment:
Following is the first .we should adjust both the position of axis by moving
the shaft, and force each thrust bearing tile bearing.At this time, due to the
adjustment Angle of the shaft rotation centerline, we can gain better
adjustment result.First, position of the shaft should have been moved before
adjustment , so that can easily make the generator rotor center and stator
center concentric, and then fixe top of the shaft on the upper guide bearing.By
adjusting each height of thrust bearing watts again, we can make the turbine
runner rotation center and the fixed labyrinth centercoincident.Meanwhile
adjust thrust each tile force beared uniform.Then we can calculate and adjust
bearing clearance with each other.
Another kind is not to adjust the force each tile of thrust bearings.We just
adjust axis by moving the shaft.This kind of situation only on the condation
that center of the unit (it means that the stator center and turbine fixed stop
leakage ring is in a straight line) and angle of spindle centerline to satisfy the is
in the reasonable range.Then Axis adjustment can meet the requirements .
Afterwards, as a reference to turbine fixed stanch ring , we can acheve the
purpose that center of rotation tunner and turbine fixed stanch ring is in a
straight line by moving shaft axis.Whether Axis adjustment is well done, it
depends that measurement of the generator air-gap and gap of hydraulic
labyrinth within the limits prescribed.
