V-belt drive installation

Transcription

1 V-belt drive installation Annex to the fan operating and maintenance instructions Contents 1 V-belt drive and its maintenance in general Operational faults and their possible causes Belt drive assembly and disassembly Assembly Alignment Tightening Disassembly Storage of belts V-belt drive and its maintenance in general Fans with the V-belt transmission are provided with a belt cover. The belt cover must be removed before performing the V-belt transmission maintenance and repair measures and mounted again before starting the fan. The belt cover must also have sufficient ventilation in order to avoid excessive heating of the belt. The V-belt drive is aligned at the factory by the manufacturer and tightened to be up and running. The belts should be retightened along with the introduction after about 30 min of use. 1. Check the V-belt pulleys and belts for wear on a regular basis. For the V-belt pulleys, there are groove gauges, with the help of which can easily and certainly establish the wear of the grooves. 2. Replace the worn pulleys and belts. In multiple belt drives all belts must be replaced at the same time, 3. Clean the pulleys and belts as required - cleaning with a solvent such as turpentine. 1

2 2 Operational faults and their possible causes Operational fault Damage, Correction failure Loose belts Tighten the new belts Belts in the grooves in different depths Correct the grooves Belt twisted into groove by force 1 2 Install the new belts by hand Hard pieces ended up in wheel grooves 1 2 Check all covers Belts are not the same length Check sorting numbers In the wheel grooves cracks or blisters on 5 Replace pulleys the casting The belt touches the fixed structures Check the distance, tighten the belts Abrasive dust gets into the drive 5 Check the covers, tighten the straps Drive undersized Check, tighten the belts Too small pulley Replace pulleys Short belt, high speed 7 8 Explore the profile options The drive stopped into tightened straps 4 Loosen the belts if the drive has to stand up for more than 2 weeks Lubricants or fuels ending up in the belts, used belt waxes Damage or failure: 7 10 Clean the drive, support leaks Sunlight, electric welding, hot air 11 Check all covers The hot place of use Explore the opportunities for cooling External clamping wheel 11 Groove wheel on the inside, adjust the pressure 1. the belt is broken 2. the belt has a soft, stretchy point 3. a belt or belts turn in the grooves 4. the drive throbs or vibrates 5. side surfaces wear out quickly 6. in side surfaces scratches or small tears 7. side surfaces soft, burnt rubber stuck in the grooves 8. side surfaces torn, cracks 9. in the outer surface scratches and tears 10. all the surfaces of the belt sticky, lumpy, lifeless rubber in the belt and in the wheels 11. surface of the belt hard, cracking on the base rubber side 2

3 3 Belt drive assembly and disassembly Assembly 1. Remove the protective grease from the sleeve and from the wheel hub. Place the sleeve into the wheel hub and align the holes 2. Grease the screws and tighten them gently into place. The locations of screws are shown in the figure below and in them, the thread is in the wheel hub, 3. Clean the shaft; then mount the wheel and the sleeve onto it. When mounting the wheel keep in mind that first the sleeve is attached onto the shaft and the wheel will then still move a little bit in relation to the sleeve 4. Tighten the screws securely with the key 5. Tap the sleeve slightly with a punch and tighten the screws again Repeat this a couple of times to make sure that the sleeve is really firmly in place 6. Check the tension of the screws from time to time 7. Fill the extraction holes with grease to prevent them from getting dirty 8. Clean the wheels from oil and grease and check the belt grooves for rust 9. Adjust the axle spread so that the belts can easily get into wheel grooves without forcing them 10. Make sure that the wheels are aligned and the axes parallel 11. Place the belts into the wheel grooves and tighten the drive Alignment Tightening Perform the alignment by placing the steel ruler against the sides of the pulleys and sliding the engine as required. The alignment has been carried out correctly when both axes and the pulleys are aligned. The great power transfer capacity of modern belts, especially of narrow the V-belts, cannot be used without the correct tightening. 3

4 Proper tightening is checked as follows: 1. Measure the length of the belt span (= free V-belt length) 2. Measure the perpendicular bending force, which causes in the belt 16 mm of deflection per one meter of the belt span 3. Compare the measured power to the table below Hihnakireysmittari Belt tension gauge Hihnataipuma- Belt deflection Voima Force Poikkeama 16 mm hihnajänteen metria kohti - Deviation of 16 mm per meter of belt span Hihnajänne belt span Belt profile SPZ SPA A smaller wheel diameter, mm Power, N Power, kp , ,

5 SPB , ,6 SPC , If the measured values of the bending force are within the provided values, the tightening is satisfactory. If the force is less than the lower value, the belts are too loose. A new drive should be tightened to the higher value of the measuring power, because the belts stretch during running-in. The belts should be tightened later on a regular basis. Belt tightening is adjusted by moving the motor. In this case, first loosen the four screws securing the motor and after the tightening is adjusted by means of a tightening screw. Here must be ensured that the pulleys are aligned and the axles are parallel. When the belts are in the correct tension, tighten the motor clamp screws. The belts with a length of up to mm, and can be tightened again after 30 minutes of use up to the higher values of the table, then retightening of the belts are unnecessary Disassembly 1. Loosen the straps for moving the motor per fan by opening the engine mounting screws and turning the locking screws 2. Remove the belts from the wheels 3. Clean the pulleys 4. Remove the screws and turn one or two of the screws, depending on the sleeve type, to the pull-out holes. The pull-out holes are shown in the figure below and the thread is in the taper bushing 5. Tighten the screws evenly until the bush is loose from the hub 6. Remove the drive from the shaft 5

6 4 Storage of belts The belts should be stored in a dry location. Contact with hot surfaces and direct sunlight must be avoided. If possible, hang the belts loosely on a single layer. The belts must not be turned into a roll. 6