Handbook Of Shaft Alignment Episode 2 Part 10 pdf

16.18.2 DETERMINING THE DESIRED OFF-LINE SHAFT POSITIONS WHEN USING THE MACHINE CASE TO BASEPLATE OR MACHINE CASE TO REMOTE REFERENCE POINT METHODS If you employed one of the following techniques to measure OL2R movement, the data you collected show how each end of the machinery moved from OL2R conditions (Figure 16.84 and Figure 16.85) . Side view Scale : Measurement points at or near each bearing Motor Multistage pump Motor Multistage pump 10 in. 10 mils Observed amount of movement from OL2R conditions view looking east for the lateral (sideways) movement 8 mils up 2 mils east 14 mils up 5 mils east 32 mils up 14 mils west 24 mils up 20 mils east 8 mils up 14 mils up 32 mils up 24 mils up Desired off-line vertical shaft positions Up FIGURE 16.84 Example of a desired off-line side view (vertical) shaft position alignment model using the machine case to baseplate or machine case to remote reference point methods. Piotrowski / Shaft Alignment Handbook, Third Edition DK4322_C016 Final Proof page 540 6.10.2006 12:03am 540 Shaft Alignment Handbook, Third Edition . Calculating machine case thermal expansion using the strain equation . Inside micrometer–tooling ball–angle measurement devices . Proximity probes with water-cooled stands . Optical alignment equipment Graph paper similar to what is used for the graphing or modeling techniques covered in Chapter 8 can be used to show the desired off-line shaft positions. The graph centerline will represent the final position of the shafts, which is often referred to as the ‘‘hot operating position’’ or running shaft positions. If the machinery shafts move from OL2R conditions, lines will be drawn on the graph paper to represent what position they should be in when off- line, so that when they move during operation, they will come in line with each other (i.e., end up on top of the graph centerline). Along the graph centerline, mark where the OL2R measurements were taken at the inboard and outboard ends of each piece of machinery. Other critical points such as the dial indicator (or laser–detector) reading point locations and foot bolt points can be shown. Once the desired off-line shaft positions are drawn, ‘‘shoot for’’ dial indicator readings can be deter- mined for the shaft positions when off-line. It should become apparent by this time that if you are using dial indicators and brackets that have sag and that the shafts should not be in line with each other when off-line, you should never want to ‘‘spin zeros’’ for the dial indicator readings. East Top view Scale: Motor Multistage pump 10 in. 10 mils 2 mils east 5 mils east 14 mils west 20 mils east Desired off-line lateral shaft positions FIGURE 16.85 Example of a desired off-line top view (lateral) shaft position alignment model using the machine case to baseplate or machine case to remote reference point methods. Piotrowski / Shaft Alignment Handbook, Third Edition DK4322_C016 Final Proof page 541 6.10.2006 12:03am Measuring and Compensating for Off-Line 541 16.18.3 DETERMINING THE DESIRED OFF-LINE SHAFT POSITIONS WHEN USING THE MACHINE CASE TO MACHINE CASE METHODS If you employed one of the following techniques to measure OL2R movement, the data you collected show how one machine case moved with respect to the other machine case from OL2R conditions: . Alignment bars or custom fixtures with proximity probes . Laser–detector systems with custom-fabricated brackets or special mounting systems . Ball–rod–tubing connector system Graph paper similar to what is used for the graphing or modeling techniques covered in Chapter 8 can be used to show the desired off-line shaft positions. The graph centerline will represent the final position of the shafts, which is often referred to as the ‘‘hot operating position’’ or running shaft positions. In these OL2R methods, it is not known how each machine moved from OL2R conditions with respect to a fixed point in space (as opposed to the previously covered methods which do). What is known is how one machine saw the other machine move. Therefore, one of the two machine cases or shafts is used as a reference shaft and its position is placed directly on top of the graph centerline. The other machine case or shaft is then drawn on the graph paper to reflect how it moved with respect to the reference shaft. Along the graph centerline, mark where the OL2R measurements were taken at the inboard and outboard ends of each piece of machinery. Other critical points such as the dial indicator (or laser–detector) reading point locations and foot bolt points can be shown. Once the desired off-line shaft positions are drawn, shoot for dial indicator readings can be determined for the shaft positions when off-line. If the alignment bar system was used to determine the machinery movement, the desired off-line side view (vertical) shaft position alignment model setup might look like Figure 16.86. A little bit of thought is going to have to be put forth to recall how the probes were positioned when reading the targets and what decreasing or increasing gaps mean when setting up the chart. It is easy to make a mistake here by misinterpreting the movement data, so it is wise to make sure both the amount of movement and the direction of movement are correct and that you have gone over the graph setup at least twice before running out and positioning the machinery with shoot for readings that are wrong. Figure 16.87 shows how the desired off-line side view (vertical) shaft position alignment model might look if you used a laser– detector system with custom-fabricated brackets or generic mounting brackets or if you used the BRTC system. 16.18.4 HOW TO DETERMINE THE ‘‘SHOOT FOR’’ OFF-LINE DIAL INDICATOR READINGS (ALSO KNOWN AS ‘‘TARGET VALUES’’) So far in this chapter, we have reviewed a number of methods to determine how machinery will move from OL2R conditions. In addition, we have been able to take these data and plot the information onto a graph showing where the shafts should be when the equipment is not running. As you can see, if all of the shafts in the drive system do not move in unison with each other (i.e., the same amount and in the same direction), the shaft centerlines should not be collinear when off-line. Since the shafts should not be in line with each other when off-line, what should the off-line alignment measurements be to insure the shafts are in the desired off- line positions similar to what is shown in Figure 16.86 through Figure 16.88. What would the Piotrowski / Shaft Alignment Handbook, Third Edition DK4322_C016 Final Proof page 542 6.10.2006 12:03am 542 Shaft Alignment Handbook, Third Edition alignment readings be if you were using the reverse indicator method, face–rim, double radial, shaft to coupling spool, or the face–face method? 16.18.4.1 Reverse Indicator Shoot for Dial Indicator Readings If you will be using the reverse indicator method to align your machinery, apply the following procedures to determine what the shoot for readings will be when aligning your machinery to compensate for OL2R movement: Motor Multistage pump Side view Scale: Motor Multistage pump 10 in. 10 mils Observed amount of proximity probe gap change from OL2R conditions Vertical probe gap increased by 12 mils from OL2R Desired off-line vertical shaft positions Vertical probe gap increased by 16 mils from OL2R Vertical probe gap increased by 12 mils from OL2R Vertical probe gap increased by 16 mils from OL2R Target bar attached to this machine Probe bar attached to this machine Up FIGURE 16.86 Example of a desired off-line side view (vertical) shaft position alignment model using the alignment bars or custom fixtures with proximity probes. The desired off-line top view (lateral) shaft position alignment model is not shown. Piotrowski / Shaft Alignment Handbook, Third Edition DK4322_C016 Final Proof page 543 6.10.2006 12:03am Measuring and Compensating for Off-Line 543 1. Plot the desired off-line shaft positions of both the driver and driven units. Figure 16.89 shows a motor and a pump plotted in both the side and top views. The amount of movement of these shafts are based on the data collected from any of the OL2R measurement techniques explained in this chapter. 2. Based on the chosen scale factor from top to bottom on the chart, measure the A and B gaps. 3. Determine whether the bottom readings taken on each shaft are positive or negative by applying the following rules. Rules to determine the sign (þ)or(À) of the measurements: a. If the actual centerline of a unit is toward the bottom of the graph with respect to a projected centerline, the reading will be positive (þ). Motor Multistage pump Side view Scale: Motor Multistage pump 10 in. 10 mils Motor defined as the reference machine Desired off-line vertical shaft positions Pump defined as the observed or target machine Laser−detector system observed that the inboard end of the pump raised upwards 20 mils Laser−detector Laser−detector Laser−detector or prism Laser−detector or prism Laser−detector system observed that the outboard end of the pump raised upwards 10 mils Up FIGURE 16.87 Example of a desired off-line side view (vertical) shaft position alignment model using a laser–detector system with custom-fabricated brackets or special mounting systems. The desired off-line top view (lateral) shaft position alignment model is not shown. Piotrowski / Shaft Alignment Handbook, Third Edition DK4322_C016 Final Proof page 544 6.10.2006 12:03am 544 Shaft Alignment Handbook, Third Edition b. If the actual centerline of a unit is toward the top of the graph with respect to a projected centerline, the reading will be negative (À). In other words, try to visualize what is going to happen to the dial indicator stem as it traverses circumferentially from top to bottom on the shaft of each machine. Is it going to move outward (negative) or inward (positive)? In Figure 16.89, the side view shows that the motor centerline appears to be higher from the vantage point of the pump, therefore the dial indicator stem will move outward as it rotates to the bottom of the pump shaft producing Motor Multistage pump Side view Scale: Motor Multistage pump 10 in. 10 mils Observed amount of proximity probe gap change from OL2R conditions Vertical probe gap decreased by 4 mils from OL2R Desired off-line vertical shaft positions Vertical probe gap increased by 5 mils from OL2R Vertical probe gap decreased by 4 mils from OL2R Vertical probe gap increased by 5 mils from OL2R Tubing connector Ball−rod Ball−rod Prox probes Up FIGURE 16.88 Example of a desired off-line side view (vertical) shaft position alignment model using a ball–rod–tubing connector system. The desired off-line top view (lateral) shaft position alignment model is not shown. Piotrowski / Shaft Alignment Handbook, Third Edition DK4322_C016 Final Proof page 545 6.10.2006 12:03am Measuring and Compensating for Off-Line 545 Up Side view Scale : Motor Multistage pump Motor Multistage pump 10 in. 10 mils Desired off-line vertical pump shaft position Desired off-line vertical motor shaft position Reverse indicator method East Top view Scale: Motor Multistage pump 10 in. 10 mils Desired off-line lateral pump shaft position Desired off-line lateral motor shaft position AB C D Where the dial indicator readings will be taken on the motor shaft with the bracket attached to the pump shaft A and B indicate the distances between the two centerlines of rotation where the readings will be taken when looking in the side view C and D indicate the distances between the two centerlines of rotation where the readings will be taken when looking in the top view Where the dial indicator readings will be taken on the pump shaft with the bracket attached to the motor shaft 0 50 10 40 20 30 + _ 10 40 20 30 0 50 10 40 20 30 + _ 10 40 20 30 0 50 10 40 20 30 + _ 10 40 20 30 0 50 10 40 20 30 + _ 10 40 20 30 FIGURE 16.89 Example of desired off-line side and top view alignment models of a motor and a pump to calculate the shoot for reverse indicator measurements. Piotrowski / Shaft Alignment Handbook, Third Edition DK4322_C016 Final Proof page 546 6.10.2006 12:03am 546 Shaft Alignment Handbook, Third Edition a negative reading. From the vantage point of the motor, the dial indicator stem will move inward as it rotates to the bottom of the pump shaft producing a positive reading. 4. Based on the chosen scale factor from top to bottom on the chart, record the C and D gaps as shown in Figure 16.89 for the top view. Remember, you should always zero your indicator on the side that is pointing toward the top of your graph paper, in this case, it is east. Apply the same logic explained in step 3 to determine if the reading will be positive or negative. 5. Apply the appropriate gaps at A, B, C,andD into the equations shown in Figure 16.90 and solve. The shoot for reverse indicator readings solution for the desired off-line shaft positions in the side and top views for Figure 16.89 is shown in Figure 16.90 assuming that there is 10 mils of bracket sag. ((±A) − (±C)) + sag/2 (2 (±A)) + sag + (±C) (± A) − (±C) 2 2 Driver + sag/2 (2 (± B)) + sag ((±B) − (±D)) + sag/2 + (±D) (±B) − (±D) 2 2 Driven + sag/2 0 Top Bottom East West 0 Top Bottom East West Motor Pump 0 Top Bottom East West 0 Top Bottom East West −28 +17−45 +40 +41 −1 sag = 10 mils ((−19) − (+31)) + 5 (2 (−19)) + 10 + (+31) (−19) − (+31) 2 2 Motor + 5 ((+15) − (−21)) + 5 (2 (+15)) + 10 + (−21) (+15) − (− 21) 2 2 Pump + 5 0 Top Bottom East West 0 Top Bottom East West ( (( ( ((( (( ( (( ) ) ) )) ))) ) ) ) ) FIGURE 16.90 General equations to calculate the shoot for reverse indicator measurements and a sample calculation based on the shaft positions shown in Figure 16.89. Piotrowski / Shaft Alignment Handbook, Third Edition DK4322_C016 Final Proof page 547 6.10.2006 12:03am Measuring and Compensating for Off-Line 547 16.18.4.2 Face–Rim Shoot for Dial Indicator Readings Figure 16.91 shows the desired off-line shaft positions of a motor and a pump in both the side and top views. In this particular case, ‘‘front side’’ face readings were taken on the pump shaft and the T-bar overlay was used to model the desired shaft positions. Similar to the procedure for reverse indicator, measure the gaps A, B, FV, and FL. Figure 16.92 shows the general equations needed to solve for the shoot for face–rim readings as well as the specific face–rim shoot for readings you would obtain for the desired off-line shaft positions shown in Figure 16.91. 16.18.4.3 Double Radial Shoot for Dial Indicator Readings Figure 16.93 shows the desired off-line shaft positions of a motor and a fan in both the side and top views. Similar to the above procedure for reverse indicator, measure the gaps A, B, C, and D. Figure 16.94 shows the general equations needed to solve for the shoot for double radial readings as well as the specific double radial shoot for readings you would obtain for the desired off-line shaft positions shown in Figure 16.93. 16.18.4.4 Shaft to Coupling Spool Shoot for Dial Indicator Readings Figure 16.95 shows the desired off-line shaft positions of a gear and a motor in both the side and top views. Similar to the procedure for reverse indicator, measure the gaps A, B, C,andD. Figure 16.96 shows the general equations needed to solve for the shoot for shaft to coupling spool readings as well as the specific shaft to coupling spool shoot for readings you would obtain for the desired off-line shaft positions shown in Figure 16.95. 16.18.4.5 Face–Face Shoot for Dial Indicator Readings Figure 16.97 shows the desired off-line shaft positions of a motor and a calender roll in both the side and top views. In this particular case, ‘‘front side’’ face readings were taken from both the motor to the drive shaft (also known as coupling spool) and from the calender roll shaft to the drive shaft. The T-bar overlay was again used to model the desired shaft positions. Similar to the procedure for face–rim, measure the gaps FA, FB, FC, and FD. Figure 16.98 shows the general equations needed to solve for the shoot for face–face readings as well as the specific face–face shoot for readings you would obtain for the desired off-line shaft positions shown in Figure 16.97. 16.19 ALIGNING SHAFTS FOR RUNNING CONDITIONS (ALSO KNOWN AS RUNNING ALIGNMENT OR ‘‘HOT OPERATING ALIGNMENT’’) The graphing or modeling techniques shown in Chapter 8 illustrated how to align two shafts with each other to insure they were collinear when off-line. If you do not want the shafts to be collinear when they are not running but want them to be in a specific desired off-line position is similar to what is shown in Figure 16.89 through Figure 16.98. The trick to offset aligning rotating machinery shafts is to shift the position of the shafts to where they will be when they are running and align the running shaft positions. Once the shafts have been shifted to their running positions, the vertical and lateral movement restric- tions can be superimposed onto the model, and the overlay line can then be used to determine the appropriate vertical and lateral repositioning movements required to put the shafts in the desired off-line positions. Piotrowski / Shaft Alignment Handbook, Third Edition DK4322_C016 Final Proof page 548 6.10.2006 12:03am 548 Shaft Alignment Handbook, Third Edition Up Side view Scale: Motor Multistage pump Motor Multistage pump 10 in. or 10 mils Desired off-line vertical pump shaft position Desired off-line vertical motor shaft position Face–rim method East Top view Scale: Motor Multistage pump Desired off-line lateral pump shaft position Desired off-line lateral motor shaft position FV B D A indicates the distances between the two centerlines of rotation where the rim reading will be taken when looking in the side view Where the dial indicator readings will be taken on the pump shaft FL A D FV is the face reading taken on diameter D when looking in the side view B indicates the distances between the two centerlines of rotation where the rim reading will be taken when looking in the top view FL is the face reading taken on diameter D when looking in the top view 10 in. or 10 mils 10 in. or 10 mils 10 in. or 10 mils 0 50 10 40 20 30 + _ 10 40 20 30 0 50 10 40 20 30 + _ 10 40 20 30 0 50 10 40 20 30 + _ 10 40 20 30 0 50 10 40 20 30 + _ 10 40 20 30 FIGURE 16.91 Example of desired off-line side and top view alignment models of a motor and a pump to calculate the shoot for face–rim measurements. Piotrowski / Shaft Alignment Handbook, Third Edition DK4322_C016 Final Proof page 549 6.10.2006 12:03am Measuring and Compensating for Off-Line 549 [...]... ( 22 )) + 10 /2 East (( 2/ 2) − (+5 /2) ) + 2/ 2 ) )) ( 2/ 2) − (+5 /2) + (+5 /2) 2 ( (( 2 West (+15) − ( 22 ) + ( 22 ) 2 ( (( 2 ) )) + 10 /2 + 2/ 2 ( 2) + 2 Bottom (2 (+15)) + 10 0 Top 0 + 42 East 2. 5 +2. 5 West 2 0 Bottom +40 FIGURE 16. 92 General equations to calculate the shoot for face–rim measurements and a sample calculation based on the shaft positions shown in Figure 16.91 Piotrowski / Shaft Alignment Handbook, ... (±FB) + face sag Motor to spool Face sag = 2 mils 0 Top ((−3 /2) − (+4 /2) ) + 2/ 2 East West (2( ((−3 /2) − (+4 /2) ) + (+4 /2) )) + 2/ 2 2 Bottom (−3) + 2 Calender roll to spool 0 Top ((+4 /2) − ( 2/ 2)) + 2/ 2 East West − (2( ((+4 /2) 2 ( 2/ 2) )+ ( 2/ 2) )) + 2/ 2 Bottom (+4) + 2 Motor to spool 0 Top 2. 5 East West +1.5 Bottom −1 Calender roll to spool 0 Top 0 +4 East West +2 Bottom FIGURE 16.98 General equations... Shaft Alignment Handbook, Third Edition DK4 322 _C016 Final Proof page 556 6 .10 .20 06 12: 03am 556 Shaft Alignment Handbook, Third Edition Motor to spool 0 Top ((±FA /2) − (±FC /2) ) + face sag /2 East West (2( ( (±FA /2) − (±FC /2) ) + (±FC /2) )) + face sag /2 2 Bottom (±FA) + face sag Calender roll to spool 0 Top ((±FB /2) − (±FD /2) ) + face sag /2 East West (2( ( (±FB /2) 2 (± FD /2) ) + (±FD /2) )) + face sag /2 Bottom...Piotrowski / Shaft Alignment Handbook, Third Edition DK4 322 _C016 Final Proof page 550 6 .10 .20 06 12: 03am 550 Shaft Alignment Handbook, Third Edition 0 Top 0 ((±A) − (±B)) + rim sag /2 ((±FV /2) − (±FL /2) ) + face sag /2 East ( (( 2 (±FV /2) − (±FL /2) 2 ) )) + (±FL /2) West ( (( 2 (±A) − (±B ) 2 ) + (±B) )) + rim sag /2 + face sag /2 (±FV) + face sag Bottom (2 (±A)) + rim sag 0 Rim sag = 10 mils Face sag = 2 mils... Alignment Handbook, Third Edition DK4 322 _C016 Final Proof page 558 6 .10 .20 06 12: 03am 558 Shaft Alignment Handbook, Third Edition Side view Up Motor Multistage pump Running pump shaft position Running motor shaft position 10 _ 0 + 10 10 20 30 40 50 _ 0 + 30 40 24 mils up 10 20 30 20 20 30 40 50 32 mils up 40 8 mils up 14 mils up Off-line pump shaft position Off-line motor shaft position Scale : 10 in 10 mils... Edition DK4 322 _C017 Final Proof page 569 26 .9 .20 06 8:41pm 569 Aligning Multiple-Element Drive Systems Motor Gear 10 _ 0 + 10 40 40 20 10 _ 0 + 50 40 30 30 20 20 30 30 10 10 24 in 28 in Up Side view _ 0 + 10 −70 Gear T W +20 +70 W E B +30 Top View East Motor Scale: 10 in 50 mils −40 B −50 Motor Gear input T 0 32 in Gear input 0 T E 30 mils 40 2 in Motor 0 10 in 30 50 20 32 in 1 in Scale: 20 40 10 in 14... +30 40 30 W +20 B −50 30 50 20 −70 E 20 40 1 in Motor 0 T 10 30 40 40 50 10 40 _ 0 + 20 30 30 48 in 10 20 20 Pump View looking east Gear output 0 T − 32 E Sag compensated readings FIGURE 17.7 Motor–gear–pump drive system layout W + 52 B +20 Pump 0 T −66 E W 2 B −68 Piotrowski / Shaft Alignment Handbook, Third Edition DK4 322 _C017 Final Proof page 568 568 26 .9 .20 06 8:41pm Shaft Alignment Handbook, Third... view 10 _ 0 + 10 20 20 30 30 40 50 40 10 _ 0 + 10 20 20 30 30 40 C 50 40 D Desired off-line lateral fan shaft position Desired off-line lateral motor shaft position Scale: 10 in 10 mils FIGURE 16.93 Example of desired off-line side and top view alignment models of a motor and a fan to calculate the shoot for double radial measurements Piotrowski / Shaft Alignment Handbook, Third Edition DK4 322 _C016... Running pump shaft position Running motor shaft position 5 mils east 10 _ 0 + 10 10 20 30 40 50 _ 0 + 10 20 30 20 30 40 20 30 40 50 40 20 mils east 14 mils west 2 mils east Off-line motor shaft position Off-line pump shaft position Scale : 10 in 30 mils FIGURE 16 .100 Side and top view alignment models for the motor and multistage pump shown in Figure 16.99 Piotrowski / Shaft Alignment Handbook, Third... Edition DK4 322 _C016 Final Proof page 559 6 .10 .20 06 12: 03am 559 Measuring and Compensating for Off-Line Side view Up Motor Multistage pump Running pump shaft position Running motor shaft position Lower 25 mils down _ 0 + 10 10 10 20 30 40 50 _ 0 + 10 20 30 20 30 40 20 30 40 50 40 Pivot here Lower 33 mils down Pivot here Baseplate restriction points Scale: 10 in 20 mils Note: Always be aware of your scale . 10 /2 (2 (+15)) + 10 East West Top Bottom 0 0 ( 2) + 2 (( 2/ 2) − (+5 /2) ) + 2/ 2 + ( 22 ) (+15) − ( 22 ) 2 2 + 10 /2 + (+5 /2) ( 2/ 2) − (+5 /2) 2 2 + 2/ 2 ((±A) − (±B)) + rim sag /2 (2 (±A)) + rim sag East. 2 ((+4 /2) − ( 2/ 2)) + 2/ 2 ((( + ( 2/ 2) (+4 /2) − ( 2/ 2) 2 2 + 2/ 2 ))) East West Top Bottom 0 (±FA) + face sag ((±FA /2) − (±FC /2) ) + face sag /2 ((( + (±FC /2) (±FA /2) − (±FC /2) 2 2 + face sag /2 ))) Calender. view 10 in. or 10 mils 10 in. or 10 mils 10 in. or 10 mils 0 50 10 40 20 30 + _ 10 40 20 30 0 50 10 40 20 30 + _ 10 40 20 30 0 50 10 40 20 30 + _ 10 40 20 30 0 50 10 40 20 30 + _ 10 40 20 30 FIGURE