Operator Manual 17315060 Rev. 0 (PS - 4) PET*STAR 4 OPERATOR MANUAL Paragraph Page 1.0 INTRODUCTION... 2 2.0 INSTALLATION... 2 3.0 ALIGNMENT... 2 4.0 SPHERICAL ROLLER BEARING & PILLOW BLOCK... 5 5.0 OUTBOARD BEARING LUBRICATION... 5 6.0 CRANKSHAFT WEB DEFLECTION... 6 2
17315060 Rev. 0 (PS - 4) Operator Manual 1.0 INTRODUCTION: The PETStar4 machines may be equipped with an Outboard bearing. The additional support of an outboard bearing is some times needed due to flywheel weight, power input, overhung load, or combination of all the above. The position of the outboard is critical to the drive side and pump side crankshaft main bearings with regards to horizontal and vertical alignment. 2.0 INSTALLATION: The outboard bearing arrangement consists of V sheave, Shaft Adapter, Pedestal, Pedestal sub base, Bearing Pillow block, double row spherical roller Bearings and back up plate as major components. The back up plate for the pillow block is included to provide a part (spacer) that can be removed for V-Belt installation, thus eliminating the requirement to remove Bearing pillow block from the Adapter shaft. On the installation of the 4 throw unit, the Pedestal will be sitting on a Pedestal sub base, which will be grouted to floor. This base will be about 12 high, six foundation bolts, cast into 12 floor, will be used to anchor the pedestal sub base. Use Epoxy grout to anchor the base firmly to the floor. See the General Arrangement drawings for the package. Shims are used to establish the level of the Pedestal, long and cross, between the top of the sub base and the bottom of the pedestal. The taper lock Sheave bushing fits to the V sheave, and will be assembled and tightened. There is a machine fit on the outboard side of the V sheave, which accommodates the adapter shaft. Bolts pass through the adapter shaft, and anchor in the V sheave. Once installed, the adapter shaft run out should be measured with dial indicator. It should be in the area of 0.002 to not more than 0.005. Shims placed between the bolting on stub shaft can be used to obtain alignment. 3.0 ALIGNMENT The following is a general guideline on method to be used to align the outboard bearing. The bearing is a double row spherical roller, self aligning and grease lubricated. It is locked onto the adapter shaft outside diameter from the V sheave by a taper bushing that is advanced on the shaft causing an expansion and corresponding internal clearance adjustment for the rollers. The 0.002 to 0.003 roller to race clearance is desired. The stabilizing ring is to be removed, thereby allowing the outer race within the pillow block to float with the compressor crankshaft axial float. 3
Operator Manual 17315060 Rev. 0 (PS - 4) After the bearing and its taper lock spanner nut are adjusted and proper internal roller bearing clearance has been achieved, assemble the bottom and top halves of the outboard bearing pillow block and torque up the cap bolts holding top to bottom of the pillow block. 3.1 Clean and de burr or otherwise fit-up the top and bottom support surfaces of the outboard bearing support pedestal. 3.2 Remove all paint, grease or any other foreign material such that only bare metal is exposed for shim support. 3.3 Move the pedestal into position under the outboard bearing. 3.4 Shim the bottom of the pedestal to the pedestal frame such that about 0.032 to 0.062 remains between the pillow block and the top of the pedestal (after putting Spacer plate). (IMPORTANT : Shim stacks of more than 0.062 thickness should be avoided, since by their thickness, they tend to become soft, and will crush a bit, leading to inaccurate support.) 3.5 Check the level of the top of the pedestal both parallel and perpendicular with the compressor using a machinists level graduated in 0.005 increments. Figure 1 Outboard Bearing Assembly 4
17315060 Rev. 0 (PS - 4) Operator Manual 3.6 The top of pedestal should be level with centerline of the stub shaft within 0.005. Adjust this level condition using steel shims or spacer plates between the bottom of the pedestal and the top to the pedestal frame. When level is achieved, bolt the bottom of the pedestal to the pedestal frame and torque the bolts to final assembled torque requirement. 3.7 Using a laminated shim pack, peel down enough shims to snugly fit under and support the pillow block. Assemble the bolts that attach the pillow block to the pedestal, leaving the bolts very loose, and not contacting the block. 3.8 Set a magnetic base dial indicator up with the magnetic base on the pedestal and the stylus of the indicator on any flat, horizontal surface of the pillow block that is parallel with the top surface of the pedestal (See Figure [1]). 3.9 Set the indicator to zero. 3.10 Torque the pillow block bolts to final assembled torque requirement. 3.11 Record the deflection of the pillow block as noted by the dial indicator. (IMPORTANT : If no deflection is measured, remove the shim pack from under the pillow block and peel off enough shims until some deflection is measured.) 3.12 Add a thickness of shims equal to the reading on the dial indicator. If the indicator showed movement of 0.010, add 0.010 thickness of shims under the pillow block. 3.13 Reset the indicator as before, and re torque the pillow block bolts. 3.14 Record the deflection of the pillow block again, and again add sufficient shims to equal the deflection measured. 3.15 Retighten the cap bolts and re-measure deflection. 3.16 Continue this process until deflection measured is less than 0.001. 3.17 When the measured deflection in the fully torque condition is 0.001 or less, loosens the assembly again and remove the shim pack completely. To the shim pack add 0.003, no more. Using a wedge, raise the pillow block slightly to allow insertion of the full shim pack with the 0.003 just added. 3.18 Insert the bolts and torque to final assembled requirement. 3.19 Roll the machine over several revolutions by hand to assure free turning of the crankshaft. 3.20 Using appropriate taper dowel pins, set dowels in the base of the pedestal to the skid frame. Dowel the pillow block in the same manner, if appropriate. (Some pillow blocks are not Dowell able, due to the configuration of their cast bases). 3.21 Reassemble the V-belts or other drive mechanism and make final adjustments. 3.22 Make a final check of the assembly by rolling over by hand. The machine should roll freely. 3.23 Lubricate the pillow block bearing with grease as required. 5
Operator Manual 17315060 Rev. 0 (PS - 4) 4.0 SPHERICAL ROLLER BEARING & PILLOW BLOCK The pillow block bearing is double row spherical, self aligning bearing, grease lubricated. This type of bearing is of split construction for convenient assembly and disassembly. The Clearance between rollers to race that is desired can be obtained by tightening the taper lock spanner nut, which expands the inner race. A spherical roller bearing pillow block assembly is mounted on a straight shaft using a tapered bore bearing and adapter assembly. Adapter mount also permits maximum flexibility in the axial positioning of the bearing on the shaft and will accommodate light locational thrust loads. Adapter mounted spherical roller bearings require the correct removal of diametrical clearance from the bearing to prevent relative rotation between inner race and sleeve or shaft. Failure to employ proper mounting procedures can cause heating and reduce bearing performance. Figure 2 Exploded view of assembly spherical bearing pillow block 5.0 OUTBOARD BEARING LUBRICATION: The outboard bearing can be lubricated by grease. Apply the lubricant directly in the bearing between the rollers during the assembly. Place the grease into the lower half of the housing until it is approximately one third to one half full in general, only a good quality mineral grease should be used, having a melting point considerably higher than the operating temperature. A higher grease level can result in over heating. Use bearing grease 6
17315060 Rev. 0 (PS - 4) Operator Manual with an extreme pressure additive. The grease should be replaced after 3500 hours operation when the condition of the load and temperature are normal, or as the conditions dictate. 6.0 CRANKSHAFT WEB DEFLECTION Final alignment of the outboard bearing is determined by checking the crankshaft for deflection at the drive end. First web deflection is the amount of opening of the first crank web that occurs, as caused by an imposed side loads from the positioning of an outboard bearing, overhung load from V belt pull, or dead weight from V sheave. With V-belts tensioned, first web deflection should be measured. Remove any blocking from the crankshaft until the crank throw nearest the driver is pointing straight up in its top vertical position, and then measure the span between the crank webs as shown in the figure [3]. The micrometer shown consists of an ordinary inside micrometer barrel with pointed extension shaft of the proper length to measure the span between the webs. Punch a mark on the crank web with the center punch and encircle the same for future use. Insert a pointed end of the inside micrometer in the prick punch mark and adjust the barrel at the other end until, it will just pass the CLOSEST portion of the opposite web. Record the reading to the nearest thousands of an inch. FIG. 3 CHECKING DEFLECTION OF CRANKSHAFT WEB WITH MICROMETER Now rotate the crank approximately 180 so it points straight down and take another reading with the micrometer. Difference between the two readings represents the amount the crank webs deflected by the vertical misalignment of the out board bearing. If the reading with the crank in the upper position is less than the reading with the crank in the lower position, the outboard bearing is too low and must be raised enough so that there is no deflection between the crank up and the crank down position. To check horizontal alignment of the outboard bearing, set the Crank throw approximately horizontal, measure between webs as before and record the readings. Rotate the crank 180 and re-measure. Loosen bolts holding the outboard bearing, and move it sideways until the horizontal readings are the same. If all four readings are alike, the shaft is in perfect alignment. Every effort should be made to obtain this condition. 7
Operator Manual 17315060 Rev. 0 (PS - 4) Before initial starting, recheck all leveling pads on the compressor, outboard bearing and driver and be sure that nuts on all foundation bolts are pulled down firmly. Make sure that all blocking is removed. The operation of the bearing should be checked during the initial run. Unusual noise should be investigated immediately and condition corrected. After the first day of the operation, the deflection at the first crank throw from the drive end should be rechecked. Although maximum difference between deflection measurement of 0.002 (0.05 mm) is allowed at this throw, every attempt must be made to keep the deflection as close to 0 (zero) as possible by resetting the position of the out board bearing. The Compressor should be allowed to operate at the normal temperature at the short time before taking a final alignment check of the outboard bearing. After making any necessary readjustment to bearing portion, dowel the housing to the pedestal with a tapered dowel. The roller bearing pillow block is to be checked after initial 24 to 72 hours of operation to make certain that the locking device has not worked loose. Therefore, the locking device should be checked for proper tightness during periodic maintenance shutdown and retighten, if required using the spanner wrench. 8