DRI-1 14-0502

MAINTENANCE MANUAL

HOLMES POSITIVE

DISPLACEMENT

AIR BLOWERS

TYPES

68, 610 AND 613 RBTM

Welgro bv

Parallelweg 187141 DC GroenloPostbus 307140 AA GroenloThe NetherlandsTel. +31 (0)544 - 46 15 72Fax +31 (0)544 - 46 40 25www.welgro.nle-mail: welgro@welgro.nl

DRI-114-0502

DRI-114-0502

INDEX

Page

SAFETY INSTRUCTIONS 3PARTS LIST 4

1 Dismantling 5

1.1 Gearwheels 51.2 Drive End Bearings and Grease Seals 51.3 Impellers 51.4 Gear End Bearings 6

2 Re-assembly 7

2.1 Gear End Headplates 72.2 Impellers 72.3 Drive End Headplates 82.4 Gear End Bearings 82.5 Drive End Bearings 82.6 Setting Clearances 92.7 Gearwheels 10

3 Lubrication 13

3.1 Oil Specification 133.2 Grease Specification 13

DRI-114-0502

DRI-114-0502

SAFETY INSTRUCTIONS

Air Blower fitting is highly skilled work and should only be undertaken by competent fitters. It is important thatthe contents of this Manual should be read and understood before carrying out any work on a Blower. All repairsshould be carried out using the approved equipment and tools.

Maintenance work on a blower can be dangerous if correct procedures are not carried out and all reasonablemeasures should be taken to safeguard those engaged in such work. It is especially important that before anywork is started the blower is isolated from the prime mover. A blower fitted to a vehicle should, where possible,be removed using safe, adequate lifting equipment. When this cannot be done the starter battery should beremoved or isolated to prevent the drive engine being inadvertently started. Special care must be taken whenworking on pressure tank vehicles as differences in pressure between the air contained in the pipework or tankand normal atmospheric pressure can cause the impellers to rotate when the drive is disconnected. To preventthe impellers being blown or sucked round whilst work is being carried out, pipework must be disconnected orblanking-off plates inserted between flanges.

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PARTS LIST

Item No Part No Description Qty perblower

1 MC 15306/01 Cylinder 12 MC 19565/01 Driving Impeller and Shaft 13 MC 19565/02 Driven Impeller and Shaft 14 MC 19563/00 Drive End Headplate 15 PC 47953/00 'O' rings Drive End R6187 26 PC 49804/00 Grease Seal 27 PC 13307/00 Drive End Bearing SKF 3308/C3 28 PC 43420/00 Drive Shaft Bearing Locknut 19 MC 15309/06 Driven Shaft Bearing Clamp Disc 110 PC 59244/00 Setscrew for Item 9 – M16 x 30 mm long 111 MC 15309/01 Drive Shaft Bearing Cover 112 MC 15309/02 Driven Shaft Bearing Cover 113 PC 36602/00 Grease Nipple 1/8 BSP for Items 11 and 12 214 MC 19564/0 Gear End Headplate 115 PC 47953/00 'O' Ring Gear End R6187 216 MC 19570/00 Gear End Headplate Insert 217 MC 19568/00 Oil Thrower 218 PC 13544/00 Gear End Bearing SKF N308 219 P 401919/00 Gear End Bearing Retaining Disc 420 PC 58956/00 Setscrew for Item 19, M10 x 16 mm long (not shown) 421 PC 10910/00 Taper Bore Gears 1 pair22 MC 15309/00 Drive Dog 123 PC 14640/01 Gear Trough 124 MC 15308/01 Gear Case 125 PC 08708/02 Tachometer Drive Bush complete 1

PC 08708/03 With Spindle 126 PC 36601/00 Grease Nipple 1/4" BSP for Item 25 (not shown) 127 PC 53105/00 Flanged Plug 3/4 BSP for Gear Case 328 PC 32305/00 Fibre Washer for Items 25 and 26 429 PC 27580/00 Dowel Pin M10 x 20 mm long (not shown) for Headplate/Cylinder 830 PC 41408/00 Key for Drive Shaft 3/8" x 1/4" x 3" long (not shown) 131 PC 73810-00 Spring Tension Pin (not shown) to fit Items 24 to 14 232 PC 64406/00 Capscrew M6 x 12 mm long (not shown) to fit Items 23 to 14 433 PC 58958/00 Setscrews M10 x 25 mm long (not shown) 52

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DRI-114-0502

1. DISMANTLING

1.1 Removal of Gearwheels

After draining the oil, remove the gearcase. Remove gear trough.

Before removing the gears, they should be marked as it is important that when the blower is being re-assembled,using existing gears, each gear should be re-fitted to the respective shaft from which it was removed. The gearteeth should also be marked so that when gears are re-fitted they mesh in their original position.

Assemble the gearwheel removal equipment as shown in Figures 1a and 1b to one gear and by operation of theoil injection equipment the gearwheel will then be released from its seating.

Removal of the gearwheel is effected by injecting oil at high pressure into the interface between the gearwheelbore and the shaft, thus expanding the gearwheel off its taper seating.

When both Gearwheels have been removed, they should be protected against damage.

Figure 1a – Arrangement of gear withdrawalequipment

Figure 1b – Gear withdrawal

1.2 Removal of Drive End Bearings and Grease Seals

To remove the bearings and grease seals it is necessary first to remove one headplate. Preferably this should bethe drive end headplate.

Remove both bearing covers, and the bearing retaining locknut from the driving shaft and the clamping disc fromthe driven shaft. Remove the setscrews which fasten the headplate to the cylinder.

Assemble the bearing withdrawal equipment on both shafts as shown on Figures 2a, 2b and 2c. When theequipment has been assembled, the headplate complete with bearings and grease seals can be removed bymeans of the Pickavant hydraulic rams. Equal pressure should be maintained on each ram to give equal pull onthe bearings, otherwise damage may occur to the headplate. The drive end bearings which are a sliding fit ineach bore of the headplate can now be removed.

The grease seals must now be pressed or driven out taking care not to damage the headplate. After removal theseals must be scrapped as they are invariably damaged during dismantling.

1.3 Removal of Impellers

Each impeller can now be removed separately by assembling the bearing withdrawal equipment at the gear endas shown in Figures 2b and 2d. With the equipment assembled, operation of the Pickavant hydraulic jack willpress out the impeller shafts from the inner race of the roller bearings.

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1.4 Removal of Gear End Bearings

Dismantle the gear end headplate from the cylinder and the bearings can then be removed from the headplate.Press out the headplate inserts and this will remove the oil throwers and inner races of the bearings. The outerrace of each bearing should then be extracted from the headplate.

Figure 2a Arrangement of bearing withdrawal equipment for driving end of the driven shaft.

Figure 2b Arrangement of bearing withdrawal equipment for drive shaft drive end and for impellerremoval.

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Figure 2c – Removal of headplate Figure 2d – Removal of impellers

Figure 4a Arrangement of Bearing Assembly Equipment

2. RE-ASSEMBLY

Prior to assembly, all parts must be thoroughly cleaned and degreased with trichlorethylene or white spirit.

2.1 Re-fitting Gear End Headplate

The headplate can now be fitted to the cylinder but before tightening the setscrews, the dowel pins must be fittedto ensure correct positioning.

If a new headplate is being fitted it will not be possible at this stage to fit the dowels as the exact location of theheadplate cannot be determined until the impeller tip clearances have been set. This cannot be achieved untilthe bearings are fitted at both ends 2.4 and 2.5.

2.2 Impellers

If new impellers are being fitted, carefully measure the length of the cylinder and compare with length ofimpellers. The impellers should be shorter in length than the cylinder by an amount equal to the sum of theaverage locating end and free end clearances given in Table 1. If this is not so, the effective length of thecylinder will have to be increased by inserting a paper gasket between gear end headplate and the end of thecylinder.

The impellers can now be fitted into the cylinder and gear end headplate, taking care that damage does not occurto the shafts or the headplate bores.

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2.3 Drive End Headplate

The drive end headplate can now be fitted making sure that it is guided onto the shaft to prevent damage to theshaft and the bores. The setscrews securing the headplate to the cylinder should not be tightened until thedowels are fitted. If a new headplate is being fitted, the notes under heading "re-fitting gear end headplate"should be followed.

2.4 Gear End Bearings

Push the 'O' ring (air deflector ring) onto each shaft and fit the headplate inserts, using a jointing compound. Tofit the inserts correctly use the tool specified in the list of maintenance equipment. Prior to fitting the bearings thebores of the headplate and the outside diameter of each bearing should be thoroughly de-greased using achlorinated solvent. The inner race of the bearing should be hard against the oil throwers.

The re-fitting of used bearings is not recommended. See Figures 4a and 4b for arrangement of bearingassembly equipment. The bearing retaining clips should now be fitted.

2.5 Drive End Bearings

The 'O' rings (air deflector rings) should be fitted followed by the grease seals making sure that the lip of the sealis not damaged. A guide which can be easily manufactured is useful for preventing seal damage.

Prior to fitting the drive end bearings the axial displacement of the outer race relative to the inner race of eachbearing must be checked. This should be carried out by placing each bearing on a flat machined metal surfaceand measuring with a feeler gauge as shown in Figure 3.

The bearings can now be fitted but making sure the bore and outer diameter of each bearing is thoroughly cleanand bearing is located hard against each shoulder. See Figures 4a and 4b for bearing assembly equipment.

Fit the bearing retaining locknut on the drive shaft making sure the threads on both shaft and locknut arethoroughly degreased. Then coat the threads with Anaerobic Adhesive 'Loctite 241'. Fit clamping disc to drivenshaft, again using Loctite on the setscrew. Pack bearings with grease and fit bearing covers.

Figure 3 The raceway displacement 'X' must be reduced to 0.002 ins (0.051 mm) maximum by addingshim-rings (PC16600/60) to the outer race. Mount the bearing with face 'A-A' towards theimpeller body and the outer race shim-rings in the bottom of the headplate bore.

Note: If a new headplate(s) is being fitted the tip clearances must be set as at 2.6 below.

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Figure 4b Bearing Assembly

2.6 Setting Tip Clearances

Position both impellers vertically. Using feeler gauges, check that the clearances between the tips of theimpellers and the bore of the cylinder are within the values given in Table 1 and that the clearances are uniformalong the entire length of the impellers.

Rotate the impellers through 180o and repeat the exercise.

After checking inlet and outlet tip clearances in this way, position each impeller and turn in the horizontal plane.Then check the clearance between the impeller tips and the cylinder bore on the horizontal centre-line. If thesemeasurements reveal the need for adjustment, this can be achieved by moving one or both of the headplatesradially relative to the cylinder. (This should only e necessary if new headplates have been fitted).

Having ensured that all tip clearances are correct, tighten up all the headplate retaining screws and fit the fourdowel pins in each headplate, re-reaming if necessary.

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DRI-114-0502

Fig 5a Arrangement of Gear Pusher Assembly

Fig 5b Gear Assembly

2.7 Gearwheels

Mounting the gearwheels also determines the front and back clearances between the impellers. Clean thegearwheel bore and its taper seating on the shaft using a chlorinated solvent. Position a gearwheel on thetapered seating of the shaft using hand pressure only, and assemble the gearwheel mounting equipment Figure5a and 5b. Ensure that the thrust race of the equipment is thoroughly clean and lightly lubricated before use.

Measure the distance from the back of the gearwheel to the headplate face by means of a depth micrometer,gauge blocks or feeler gauges.

With the torque wrench set to the required torque as given in Table 2 and using the 16 mm socket on thesetscrew, Item 7 in Figure 5a, the gear can then be pressed onto the shaft. When the required torque has beenreached, re-measure the gear to headplate distance and verify that the minimum push-up distance as shown inTable 1 has been achieved. If the push-up distance is grossly exceeded, it is probable that the gearbore andshaft may need re-cleaning. This will necessitate removal of the gear and repeating the procedure.

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Before mounting the second gearwheel, the impellers must be set in their correct relative positions. This is doneby positioning the impellers parallel to each other with their major axes at 45o Figures 6b and 6d, and insertingfeeler gauges equal in thickness to the clearance specified in Table 1 between them.

Whilst holding the impellers in this position, mount the second gearwheel by hand. Rotate the impellers andcheck that the front and back clearances are equal.

With feeler gauges between the impellers, press on the second gear using the torque wrench and socket. Afterchecking that the second gear has been fitted correctly, re-check front and back clearances. If any adjustment isnecessary, remove one of the gearwheels, thoroughly clean the bore and shaft and repeat the exercise.

Having ensured that all internal clearances are correct, fit the gear trough and coat the threads of the retainingscrews with Anaerobic Adhesive. When tightening the retaining screws make sure there is an even clearance atall points between the tips of the gearwheel teeth and the inside of the trough. Refit the gearcase using a non-setting jointing compound and fill the gearcase with oil to the correct level as detailed in the Installation andOperating Instructions.

Identification of Front and Back Clearances

Figure 6a Figure 6c

Figure 6b Figure 6d

Notes to Figure 6

1. The leading flanks of the driving impeller (ie those two flanks which face in the direction of rotation andwhich are marked 'F' on Figures 6a to 6d) form 'FRONT' clearances when in engagement with the drivenimpeller

2. The trailing, or rearward-facing flanks of the driving impeller (marked 'B' on Figures 6a to 6d) form 'BACK'clearances when in engagement with the driven impeller.

3. Each complete revolution of the drive shaft presents two 'FRONT' clearances and two 'BACK' clearances.

4. Figure 6a shows a position in which a 'BACK' clearance has just ended and a 'FRONT' clearance is aboutto start.

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5. Figure 6b shows the impellers advanced through 45o from the position in Figure 6a and clearly indicatesthe 'FRONT' clearance formed between the mating flanks of the two impellers.

6. Figure 6c shows the impellers advanced a further 45o to a position where the 'FRONT' clearance has justended and a 'BACK' clearance is about to start.

7. Figure 6d shows the impellers advanced a further 45o and clearly indicates the 'BACK' clearance formedbetween the mating flanks of the two impellers.

8. An advancement of the impellers through a further 45o from the position shown in Figure 6d would bringabout a return to the position in Figure 6a with the cycle ready to start again.

9. A 'BACK' or a 'FRONT' clearance is presented through a full 90o of rotation of the impellers, ie from theposition shown in Figure 6a to the position shown in Figure 6c or between any other two similar positions.

Internal Clearances Gearwheel Mounting Data

Table 1 Table 2

mm inches Torque Setting 16.63 kg/m (120 lbs/ft)Inlet Tip 0.203-0.254 0.008-0.010 Push up distance 1.397 mm (0.055 inches)Centre Tip 0.153-0.254 0.006-0.010Outlet Tip 0.203-0.254 0.008-0.010Gear End 0.305-0.381 0.012-0.015Drive End 0.076-0.127 0.003-0.005Fronts 0.381-0.483 0.015-0.019Backs 0.381-0.483 0.015-0.019

List of Maintenance Equipment

Item No Qty Code Description

1 1 C 15920/01 Mild Steel Cup2 1 C 15920/02 Mild Steel Ring3 1 C 15920/04 Adaptor4 1 C 15920/06 Mild Steel Outer Ring5 1 C 15920/07 Oil Injector Adaptor6 1 C 15920/08 Mild Steel Gear Stop7 1 PS 98609 M16 x 45 mm long Hexagon Head Setscrew8 1 PC 15252/12 Thrust Bearing SKF 514069 1 PC 15930/15 Internal Circlip Ref 7000-80

10 1 PC 15930/16 Oil Injector SKF 22627011 1 PS 98606 M16 x 30 mm long Hexagon Head Setscrew12 1 PC 15930/20 Torque Wrench Britool EVT 2000/RR13 1 PC 15252/14 16 mm (24 A/F) 1/2" square Drive Socket14 1 C 12346/01 Bearing Pusher15 1 C 12346/03 Drive End Bearing Pusher Adaptor16 1 C 12346/09 Gear End Bearing Pusher Adaptor17 2 C 12347/01 Ram Dummy End18 4 C 12347/02 Knurled Nut19 4 C 12347/03 Bearing Drawbar20 4 PC 12348/08 Collar21 2 PC 12349/10 Pickavant Crossblock No 15122 4 PC 12349/36 7/16" BSF x 2.1/2" long Capscrew23 2 PC 12475/21 Pickavant Ram No JWP 4024 4 PC 12587/01 Bearing Drawbar Adaptor25 1 C 19778 Headplate Insert Driver

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3. LUBRICATION

The timing gears are housed in a gearcase fitted with troughs which control the amount of oil supplied to the gearteeth. The oil used should be suitable for the minimum ambient temperature (cold starting) and for the highest oiltemperature reached on maximum load.

Fill the gearcase with the appropriate grade of oil until it overflows from the oil level/filler hole. Allow the excessoil to drain before fitting oil level filler plug. This must be done when the blower is not in operation. Overfillingmust be avoided as this will cause the gears to run hot, resulting in damage. The oil level should be checkedweekly or every 100 working hours. Drain and refill the gearcase to the correct level every six to twelve monthsdepending upon the condition of the oil. When there are considerable seasonal temperature variations, it may benecessary to change the grade of oil at certain times during the year.

The bearings at the timing gear end are splash lubricated by the gears whilst those at the drive end are greaselubricated. Before start up, apply grease to the nipples until it appears at the grease release vent.

These vents should be kept clear and free from paint. Give two or three shots of grease to each drive endbearing every 1,000 working hours or every six months, whichever comes first.

If a lubricant from one of the major oil companies cannot be acquired, the specifications listed in 3.1 and 3.2should be complied with. Any reputable oil company should be able to supply satisfactory lubricants based onthese specifications.

3.1 Oil Specification

The oil used should be a straight mineral oil which may contain anti-wear, anti-rust, anti-foam and anti-oxidantadditives. The oil should not contain either an extreme pressure additive or additives which emulsify. The oilshould have a viscosity of not more than 2,500 centistokes at the minimum ambient temperature (cold starting)and not less than 30 centistokes for the highest oil temperature reached on maximum load. When there areconsiderable seasonal variations in ambient temperatures, summer and winter grades of oil will be required.

3.2 Grease Specification

A High quality No 3 (National Lubricating Grease Institute) mineral oil grease having a calcium complex or alithium base should be used.

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YOUR LOCAL DISTRIBUTOR IS:

DRI-114-0502

Welgro bv

Parallelweg 187141 DC GroenloPostbus 307140 AA GroenloThe NetherlandsTel. +31 (0)544 - 46 15 72Fax +31 (0)544 - 46 40 25www.welgro.nle-mail: welgro@welgro.nl