support roller - aks

KILN SUPPORT ROLLER REPLACEMENT &

ADJUSTMENT

SUPPORT ROLLERS

General causes for replacing the Support Roller are :

a. Scoring in shaft due to entry of foreign particles.

Why Support Roller Needs Replacement?

General causes for replacing the Support Roller are :

Scoring on Bearing Liner

Why Support Roller Needs Replacement?

General causes for replacing the Support Roller are :

b. Step formation in roller.

Why Support Roller Needs Replacement?

General causes for replacing the Support Roller are :

c. Wear in the O/D of the Roller.

Why Support Roller Needs Replacement?

Conical Taper Wear Concave/ Convex Wear

General causes for replacing the Support Roller are :

d. Fitting between Roller & Shaft.

e. Cracks in Shaft/ Roller.

Why Support Roller Needs Replacement?

SUPPORT ROLLER REPLACEMENT 1. It is advisable to replace the support rollers in pair.2. Take Kiln shut down.3. Provide “ V” saddle supports below the Kiln Tire and lift the Kiln by Hydraulic Jacks so

that tire is free from supporting rollers.

SADDLE SUPPORT Contd...

SUPPORT ROLLER REPLACEMENT

SADDLE SUPPORT AT SITE Contd...

SUPPORT ROLLER REPLACEMENT

SADDLE ON LOAD – KILN LIFTED Contd...

GAP BETWEEN ROLLER & TYRE

SUPPORT ROLLER REPLACEMENT 1. Mark the present location of the support rollers.

INITIAL LOCATION OF BEARING HOUSING MARKES ON THE BASE FRAME

SUPPORT ROLLER REPLACEMENT 2. Unscrew the thrust bolts and push out support roller assembly away from the kiln

center line.

SUPPORT ROLLER REPLACEMENT 3. Remove the support roller bearings after resetting the support roller over some

packing.

SUPPORT ROLLER REPLACEMENT 4. Lift the support rollers and take away.5. Take out the bearing liners and blue match it with shaft of the new support roller.

SUPPORT ROLLER REPLACEMENT 1. Assemble the bearing liners back in the bearing.2. Bring in the new support roller and assemble it with its bearings.3. Push in the new support roller assembly. Assemble the thrust bolts.4. Check alignment of support rollers with respective kiln center line axis.5. Lower the Kiln over new support rollers.

After opening the Bearing the liner metal has to be scrapped to make a line contact with the shaft.

Bearing collar also scrapping has to be done and match with the roller collar area.

The spherical seat of the bearing also has to be checked.

There will be nos on each bearings according to that blue match has to be done on the support Roller shafts.

Punch the same no on the shaft also.

BEARING SCRAPPING

1

2

3

4

BEARING SCRAPPING

For Blue matching the bearing liner with shaft we have to slide the bearing liner above the shaft Axially.

For Blue matching the bearing liner collar with support roller collar we have to slide the bearing on the shaft Radially.

For spherical seat of the bearing with housing has to be checked by rotating the bearing axially and radially.

BEARING SCRAPPING

SUPPORT ROLLER ADJUSTMENTWhat are the three main reasons for making roller adjustments on rotaryequipment?

Primarily, adjustments should be performed with the ultimate goal to control the axial thrust of the unit, while relieving the thrust pressure on the individual rollers.

Another important reason for regular adjustments is to correct any alignment imbalances, focusing on OEM specified positions for the rollers.‐

Thirdly, adjustments are conducted in case of mechanical problems with the unit. For example, a unit with a hot or damaged bearing may have to be adjusted to compensate for the problematic roller, relieving the thrust on the individual bearing. This, of course, is an extreme measure, but unfortunately more common than it should be. Compensating for one individual bearing can cause the others to absorb the load, increasing wear and failure in other areas. When good preventative maintenance programs are in place, we notice that such reactionary solutions aren’t necessary.

SUPPORT ROLLER ADJUSTMENTWhat type of wear conditions will affect the thrust of the unit?

Most common wear conditions are concave and convex wear patterns where thetire wears in a crowned type pattern and the roller wears in a dished out shape as ‐the tire sits down into it. This should be of concern because it means the tire has been mechanically locked into place as it wears down into the rollers and can’t move very well in one direction or another. This can also lead into further thrusting issues and possibly bearing problems on individual rollers.

Contd….

SUPPORT ROLLER ADJUSTMENTIn order to minimize the additional thrust on any one roller and distribute the load to the others, we have to skew the rollers intrinsic to the design of the unit. If you look at the diagram below, you will notice where, in one case, we put pressure on the downhill side of the rollers.

Contd….

SUPPORT ROLLER ADJUSTMENTA common practice we see often is adjusting only one roller to try to drive the unit. This happens mainly because it is the easiest to access, or may be the coolest roller in an extremely hot environment. The result is having a single roller taking on the majority of the unit’s thrust and, because of its negative long term effects, we do not recommend this practice.Another type of wear pattern that can occur over an extended period of time is conical or tapered. This is a particularly concerning type of wear because it can cause the axis of the tire to tilt and drive into the retaining blocks, leading to mechanical as well as thrust problems.

Contd….

SUPPORT ROLLER ADJUSTMENTSome more wear patterns you may encounter — diagonal marks are indication of roller maladjustment; a band of pitting marks on one side of the unit can mean there is too much pressure on that side; and flat spots are noticeable when other problems arise with the unit, so make sure to look into all possible causes before making the adjustment.

Contd….

SUPPORT ROLLER ADJUSTMENTWhat are some indicators that the rollers are mis adjusted?‐

There are three primary signs to look for: temperature, vibration and wear patterns.

An increase in the temperature in the bearing taking the load is a very strong indicator of excessive thrust and wear. Unusual vibration signals the bearings are overloading.

Thirdly, we look for specific wear patterns. The unit might present concave or convexpatterns; spalls or metal flaking where the tires are thrusting too hard; diagonal marks showing a excessively skewed roller; or even flat spots, indicating the gear is bottoming in the pinion. Any of these signs point to undesirable mechanical conditions and adjustments will need to be made.

Contd….

SUPPORT ROLLER ADJUSTMENTWhat is the best way to adjust rollers to not have alignment issues?

The best way to adjust your unit’s rollers falls within the best practices of alignmentprocedures outlined in your OEM specifications. The key adjustment advice we can offer is to always balance the load between all rollers versus one particular roller. It is a common practice as well to adjust the height of the gear from bottoming in the pinion by moving the rollers in on the drive pier. This will eventually cause a misalignment of the unit that can contribute to wear conditions.

Contd….

SUPPORT ROLLER ADJUSTMENT

SUPPORT ROLLER ADJUSTMENT

• For the kiln to go up • How should be skewed the rollers ?• As the Tractor’s front tires

Kiln discharge

SUPPORT ROLLER ADJUSTMENT

SUPPORT ROLLER INSPECTION1. CHECK

Surface Contact Weather Tyre Lifts in Same Position Step Formation to be Removed Graphite Blocks Thrust ( Principle/ Types-Disc, Washer, Brass Ring Bolted to Mounting),

Direction & Amount.

2. Methods to Check Thrust (Fuller Instrument, Knocking with Hammer, Shiny Surface of Disc, Position of Supp. Roller)

3. Skewing Causes Thrust

4. Skewing Causes more Stress in the System, Accelerates Wear

5. CHECK Lubrication Water Flow Journal Condition Bearing Liner Once in Three Years Replace Oil/ Clean Sump Every Six Months or Earlier if Contamination

Due to Dusty Environment takes Place Oil Tray Perforations/ Slope Chemically Clean Water Jackets Regularly, depending Upon Quality of

Cooling Water Thrust Plate/ Washer for Roughness

6. Heating Up of Bearings Check for Presence of Above Factors Provide External Cooler for Oil If Symptoms Persist (More that 02 hrs or so), plan to Stop the Kiln, Inspect

& take action accordingly

SUPPORT ROLLER INSPECTION

THANK YOU