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Hayward Gordon Mixer Maintenance Training Presentation. Project: ? Equipment: ?. MBX Mixer Maintenance. Equipment Supplied: i.e. Hayward Gordon Mixer Model MBX-55Q c/w 20 hp 1800 rpm motor, quill gearbox design, dual 74” 3AL39 impellers.
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Hayward Gordon Mixer Maintenance Training Presentation Project: ? Equipment: ?
MBX Mixer Maintenance Equipment Supplied: i.e. Hayward Gordon Mixer Model MBX-55Q c/w 20 hp 1800 rpm motor, quill gearbox design, dual 74” 3AL39 impellers. Mixer output speed of 56 rpm. Wetted parts are 316ss.
MBX Mixer Maintenance Training Outline: • Introduction. • Mechanics of mixing - Equipment overview. • Gearbox overview • Maintenance – general • Maintenance – motor • Maintenance – gearbox lubrication • Maintenance – wet end • Trouble shooting • Equipment start-up.
Introduction Hayward Gordon Ltd. is both a manufacturer of hard metal solids handling centrifugal pumps as well as a full line of mixers. Hayward Gordon Ltd. has been supplying mixers for over 45 years acquiring considerable expertise in the field. Our industry focus is municipal, mining, chemical and petro-chemical. We offer a full range of top, side, and bottom entry mixers. For this project the mixers incorporate our MB series of helical/bevel gearboxes.
Mechanics of Mixing • Mechanically mixers consist of the following components: • Drive end. • Speed reduction • Mounting • Shaft • Impeller system
Mechanics of Mixing • Drive end – typically an electric motor. • Speed reduction – gear reducer, V-belt drive or combination of the two (gear reducer is most common). • Mounting – either open tank or close tank. • a) open tank: base plate or pedestal • b) close tank: flange mounting requiring a sealing device (mech. seal, etc.) • Shaft – transmits torque to the area of application. • Impeller system – one or more impellers designed to “pump” fluid through the impeller/s and produce “turbulence” both of which are essential to mixing.
Mixer Mechanical Overview Gearbox Quill box Motor Shaft Impeller
Gearbox Overview High speed output shaft Housing No leak drywell
Gearbox Overview High speed helical gearing low speed bevel gearing Low speed output shaft
Gearbox Overview High speed bearings – oil lubricated low speed bearings – grease lubricated
Mixer Maintenance - General • Monitor agitator for excessive vibration – a large change in vibration levels may indicate a bent shaft or missing impeller blade. • Visually inspect gearbox for oil leaks. • After first week of operation check alignment of the mixer and tighten all external bolts and plugs where necessary. • All hardware should be checked 2-3 months after initial start-up and at each scheduled shut-down. • All hardware should be re-torqued to the values indicated in the manual.
Motor Maintenance • Follow manufacturers recommended maintenance times. • Grease bearings (if required) as per manual
Gearbox Maintenance - Lubrication To ensure long gearbox life it is critically important to properly monitor lubricant quality and quantity and maintain lubricating schedule. All MB units are splash oil lubricated. The oil is picked up by the revolving elements and distributed to all bearings (except grease lubricated low speed shaft bearings) and gear meshes. Oil and grease lubrication is addressed separately in this training.
Gearbox Maintenance – Oil Lubrication After first month’s service: • Operate unit until old sump oil reaches normal operating temperature. Shut the unit down and drain immediately • Immediately flush unit with an oil of the same type and viscosity grade as the original charge. • Rapidly pour or pump a charge equal to 25-100% of the initial fill through the unit or until clean oil flows through the drain. • Close the drain and refill the unit to the correct level with new or reclaimed oil of the correct type and viscosity. • If determined to be in good condition by the supplier, reclaimed oil may be reused if it is filtered through a 40 micron or finer filter.
Gearbox Maintenance – Oil Lubrication • The recommended grade oil should be used based on ambient temperature. • Change oil a minimum of every 2500 hours of operation or 6 months, what ever occurs first
Gearbox Maintenance – Oil Lubrication • Test oil regularly. Inspect for high concentration of metal filings (this could indicate gear wear) • Check oil level weekly • Oil changes should be more frequent in hot, humid or dusty environments. • External oil pumps and filters can be installed in very harsh conditions.
Gearbox Maintenance – Oil Lubrication Oil Fill Oil Vent c/w dipstick Oil Drain
Gearbox Maintenance – Grease Lubrication All lower LS (low speed) bearings are packed with grease at the factory. For an MB mixer c/w quill design there are four (4) grease fittings. Prior to operation of the unit apply a few shots of grease to each of the grease fittings.
Gearbox Maintenance – Grease Lubrication L.S. bearing grease fittings
Gearbox Maintenance – Grease Lubrication L.S. bearing grease fitting L.S. bearing grease fitting
Gearbox Maintenance – Grease Lubrication TABLE 10 - GREASES FOR GREASE LUBRICATED BEARINGS AND GREASE PURGED SEALS** 0F TO 200F (-18 TO 93C)
Wet-end Maintenance – Rigid Couplings Rigid Couplings • Coupling have male/female spigots for accurate alignment (no match marking required) • Top Coupling is shrink fitted and held in place with thrust plate and bolts • Hex Head cap screws (minimum grade 5) clamp couplings together.
Wet End Maintenance – Rigid Couplings Rigid Couplings • Coupling have male/female spigots for accurate alignment (no match marking required) • Hex Head cap screws (minimum grade 5) clamp couplings together with lock washers and hex nuts.
Wet End Maintenance - Impeller Blade to Hub arrangement • Blades placed on front side of hub (Blade is ‘pushed’ through the water) • Hex Head cap screws with washers and double nutting ensure strong clamping result between blade and hub.
Impeller breakdown Impeller hub Impeller blade Impeller hub ear and bolting
Trouble Causes Action Gear Wear 1. Improper backlash If backlash is insufficient, adjust to specifications. Refer to factory. 2. Gear Misalignment Check contact pattern; should cover approximately 75% of face, preferable in center area. Check condition of bearings. 3. Twisted or distorted housing Check shimming and stiffness of foundation. 4. Unit overloaded Reduce the loading or replace with drive of sufficient capacity. 5. Improper oil level Check level indicator that oil level is accurately at level indicated on housing plus 1/4”, minus 1/4”. 6. Bearings out of adjustments Make sure all bearings are not pinched. All shafts should spin freely when disconnected form loads. Adjustable tapered bearings must be set at proper lateral clearance. 7. Wrong grade of oil Check that oil grade specified in lubrication instructions. If it is not, clean unit and refill with correct grade. 8. Contaminated oil Check that oil grade specified in lubrication instructions. If it is not, clean unit and refill with correct grade.
9. Coupling misalignment Disconnect couplings and check alignment. Realign as required. 10. Excessive speed Reduce speed or replace with drive suitable for speed. 11. Torsional or lateral vibration These vibrations will occur thru a particular speed range. Reduce speed to at least 25% below critical speed. System mass elastic characteristics to be adjusted to control critical speed location. If necessary, adjust coupling weight and stiffness and shaft lengths and diameters. 12. Rust due to water or humidity Make necessary provisions to keep out water. Use lubricant with good rust inhibiting properties. Make sure bearings are covered with sufficient lubricant. 13. Bearing exposed to an abrasive substance Make necessary provision to keep out abrasive substance. Clean and flush drive thoroughly and add new oil. Replace worn bearings. Abrasive substance will cause excessive wear; evidenced by dulled balls, rollers, and raceways.
Bearing Failure 1.Unit Overloaded See Overheating Item 1. Abnormal loading results in bearing flaking, cracks and fractures. 2.Excessive overhung load Reduce overhung load, use outboard bearing, or replace with unit having sufficient capacity. 3.Excessive speed Reduce speed or replace with drive suitable for speed. 4.Coupling misalignment Disconnect couplings and check alignments. Realign as required. 5.Bearings out of adjustment See Overheating Item 3. If bearing is too free or not square with axis, erratic wear pattern appears in bearing race. 6.Insufficient bearing lubrication See Overheating Items 2,6,7,8. Improper lubrication causes excessive wear and discoloration of bearing. 7.Rust due to water or humidity Make necessary provisions to keep out water. Use lubricant with good rust inhibiting properties. Make sure bearings are covered with sufficient lubricant. 8.Bearing exposed to an abrasive substance Make necessary provision to keep out abrasive substance. Clean and flush drive thoroughly and add new oil. Replace worn bearings. Abrasive substance will cause excessive wear, evidenced by dulled balls, rollers, and raceways.
Overheating 4. Dry oil seals 1. Unit overloaded Oil seals should be lubricated. If provision has been made for greasing, apply grease; otherwise apply small quantity of oil externally until seal is broken in. Reduce the loading or replace wit drive of sufficient capacity. 2. Improper oil Level Check level indicator that oil level is accurately at level indicated on housing plus or minus 1/4”. 5. Clogged breather Breather should be open and clean. Clean breather regularly in a solvent. 3. Bearings out of adjustment Make sure bearings are not pinches. All shafts should spin freely when disconnected from load. Adjustable tapered bearings must be set at proper lateral clearance. 6. Wrong grade of oil Check that oil is grade specified in lubrication instructions. If it is not, clean unit and refill with correct grade. 7. Contaminated oil Check oil for oxidation, dirt, and high sludge content. Change oil. 8. Coupling misalignment Disconnect couplings and check alignment. Realign as required. 9. Excessive speed Reduce speed or replace with drive suitable for speed.
Shaft Failure 1.Coupling misalignment Realign equipment as required. 2.Excessive overhung load Reduce overhung load. Use outboard bearing or replace with unit having sufficient capacity. 3.Unit overloaded Reduce the loading or replace with drive of sufficient capacity. 4.High energy loads or extreme repetitive shocks Apply coupling capable of reducing shocks and if necessary, replace with drive of sufficient capacity to withstand shock loads. 5.Torsional or lateral vibration These vibrations will occur thru a particular speed range. Reduce speed to at least 25% below critical speed. System mass elastic characteristics to be adjusted to control critical speed location. If necessary, adjust coupling weight and stiffness and shaft lengths and diameters.
Summary When requesting spare parts: Provide Unit Model number Provide Hayward Gordon Serial number. Item numbers of parts required Maintenance Manuals are accessible on our website at www.haywardgordon.com