Installation, operation and maintenance manual
V-Belt replacement work instructions A publication by SKF Power Transmission
Content 1. Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Safe Working Environment . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Pre-requisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6. Appendix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
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1 Scope This document covers the replacement of SKF V-belts in drives and the maintenance inspection procedure required to ensure the longest possible lifespan from the product. This document includes: • Situational check – awareness of the working environment to ensure safety • Tools – best practices and minimum requirements for most applications • Best practice – from a manufacturers’ perspective, the requirements to achieve best product performance • Standards – the requirements for drive repair and installation based on international standards
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Note! The information contained in this work instruction manual is given as a general guideline for the installation and replacement of Industrial V-belts. It is the responsibility of the installer to ensure all safety procedures and requirements of the site are adhered to. The information herein is given in good faith and based on accepted engineering practices. SKF standard warranty applies and is limited to product defects only.
Disclaimer: This is not a drive design check document, but a procedure to follow for maintaining and installing V-belts. If a drive design check is required, please refer to SKF Belt Drive Design Manual (PUB 6875), or the online SKF V-belt Design Programme (www.skfptp.com).
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2 Safe Working Environment
CDaauntgieorn The procedures mentioned are GENERAL Guidelines only. Company and site procedures with regards to occupational health and safety should take precedence.
The changing of V-belts in any application requires attention to safety requirements. Adhering to the precautions below will ensure a safe working environment and reduce problems in the drive’s performance during its operational life. 1 Electrical safety – ensure ALL power is disconnected. Ensure control room lockouts and signages stating ”down for maintenance, do not power on” are in place. This is to isolate machinery from accidental start up, until such time as all maintenance is completed. The best procedure is a signed work order allowing only authorised maintenance personnel to release the machine after the safety check is completed. 2 Trained Staff – Ensure personnel working on the machines are correctly trained. They should complete safety induction and possess the required skills for mechanical maintenance. Knowledge of V-belt maintenance will enable them to understand the priorities and requirements before the drive start-up. 3 Check Machine Components – check the positioning of the machine components, such as heavy flywheels, counterweights, gears and clutches in a neutral position to avoid accidental moving. (If unsure, refer to the machine manufacturers for help for these items before commencement of maintenance). 4 PPE, Clothing - the correct clothes to wear for the belt maintenance should include: Non-bulky clothing, with no loose sleeves, or lab coats opened. Wear gloves for inspections of pulleys and components to ensure injury from sharp components is minimised. The PPE rules of the site should be followed for this maintenance. However in all belt drive maintenance instances, when dealing with heavy items, safety shoes and glasses should be worn as a minimum precaution. 5 Drive access – the surrounding environment of the belt drives needs to be kept clean from clutter. Floors and surfaces should be clean and dry, for operator safety. Any overhead obstructions that might cause possible injury should be noted – ”Am I safe?” should be an important part of each operators thoughts through the entire maintenance procedure.
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Electric current
6 Drive Guarding – the rotating equipment should be guarded for operator safety and to ensure an external influence doesn’t damage the belts. The use of partial guards or unsafe guards is not recommended, as these tend to give a false sense of security, and may lead to possible unsafe actions. 7 Test Run – before being returned to normal operational conditions, check the drive thoroughly and account for all tools used. Ensure guards are securely re-fastened. Run the machine to ensure that any changes made are working correctly. If corrective action is required, it should be undertaken at this time - before a full return to production. General guidelines for belt drive guard designs. • Complete enclosure of the drive belt system should be mandatory – the guard should limit any entry or access in ALL directions. • Ventilation – as all V-belt drives generate heat, the heat needs to be dissipated through the ventilated sides, and possibly bottom, of the drive guard. • The size of the ventilation holes or mesh screens needs to be small enough to limit ingress of materials, but large enough to allow unrestricted airflow. • Inspection panels – the guards need to be designed with inspection panels to allow for visual checks, and if possible also to allow tension of drives without full guard removal. • A safety shutdown system (e.g. limit switches) should be incorporated in the guard access cover, so that if the guard is opened, the system advises and/ or stops the drive. • Weather protection – if an external drive system is used, it is important to take into account the anticipated weather conditions in the area to ensure the guard design is adequate for hot or wet environments. Belts run best under dry conditions, so protection from moisture is mandatory. • Keep the design simple – for ease of repair – if damaged. Complicated designs can be hard to repair and typically, the repair is never done.
3 Prerequisites Typical tools required for installation of belt drives should include: • Spanners, sockets and shifting tools to loosen or remove bolts and nuts • Allen keys for grub screws • Hammers – soft and hard, for adjustments • Screwdrivers for adjustments and cover removal • Tension tools for setting accurate belt tension • Shaft alignment tools – e.g. Laser system, straight edge are recommended • Pulley/sheave groove wear check profiles – to make sure that the pulley conditions are good. This is a major prerequisite for belt preventative maintenance
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4 Procedure The basic procedure to replace, re-install or maintain a V-belt drive is listed below and in the following appendix. The instructions cover all V-belt types including wrapped (jacketed or envelope construction) type and CRE (Cogged Raw Edge), and also includes the SKF ‘XP’ variation of the wrapped type. Adhere to the following procedure when changing or installing a V-belt drive, regardless of the application. This is the Best Practice, as prescribed by SKF PTP. Caution • Ensure ALL power is disconnected, and the drive isolated. • Double check before work commences. Exposure to a bare rotating shaft can be harmful. • Ensure all personal are familiar with the Drive Safety Checklist for a safe working environment! • Conduct a toolbox talk prior to starting the installation – ensuring awareness of the environment, and that all parties understand the task being undertaken, and highlighting any potential hazards!
1 Inspection (guard) – as components are removed, inspect for damage or wear. Check guarding for any damage or signs of wear or rubbing. Also check for signs of grease or oil that may have escaped from bearings. This may indicate other problems. 2 Belt inspection – Visually inspect existing V-belts before belt replacement. This will show any wear patterns or any unusual wear on the drive system. Belt wear may show signs that other trouble-shooting is required to ensure better belt life. Replace all belts that are damaged – important note: Sets of belts must be replaced, not just one belt on a drive system. see appendix 1, V-belt trouble-shooting. Remove belts by shortening the center distance and making the belts loose (do not pry the belts off as damage might occur to the belts and pulleys) 3 Pulley inspection – If the drive is new, check the pulleys for any damage in transit. Also ensure the pulleys are designed according to ISO/RMA standards for groove angle and dimensions – i.e. to match each other (essential if running banded belt sets). For existing pulleys, check for groove wear, and any external damage. The use of pulley profile gauges is strongly recommended - these will confirm any groove wear, and also ensure pulley groove angles are correct.
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4 Pulley installation – there are different types of shaft fixing methods available for pulleys in todays’ market, such as taper bush, QD, locking assemblies, etc. We will advise how to install for the main global type – the taper bushing series. This system consists of a tapered bushing (external taper) that fits into a matching pre-machined pulley. To install, see document ”Taper Bushing Installation” in appendix II When fitting the taper bushing, ensure the recommended torque settings are used for the securing of each grub screw. This is required to apply the correct holding torque of the bushing, and failure to tighten correctly may result in failure of bushing. See ”Taper Bushing torque settings” in appendix III 5 Drive alignment – the accuracy of the drives’ alignment will ensure long and efficient pulley and belt life, maximise power transmission capability, and mimimise vibration. A straight edge or laser alignment system is recommended, see appendix IV Installation and Maintenance, for reference to alignment and methods. 6 Drive tension procedure – the tension procedure is attached – see appendix V Tensioning methods for V-belts. For manual calculation of accurate tensions for each drive, please see appendix VI Calculating belt tension. This covers the standard procedure for each type of the various tension tools now available, to suit all Vbelt types. 7 Test run – before being returned to normal operational conditions, check the drive thoroughly, and account for all tools used. Ensure guards are securely re-fastened. Run the machine to ensure that any changes made are working correctly. If corrective action is required, it should be undertaken at this time - before a full return to production.
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Note! Remember to ensure that all power is disconnected and that the drive is isolated.
5 References The procedure listed above is the typical overall tension procedure. For the efficient performance of the V-belts, there is also a requirement to understand the time interval between each re-tension, and how the belt is affected during the initial ‘running-in’ post ‘initial installation’ period.
Wrapped (envelope) belts SKF wrapped belts come in two types: Standard wrapped (jacketed) and XP (Xtra Performance) type. These are similar in outward appearance, but differ in internal construction. As such, they have different requirements for installation re-tensioning.
Standard Wrapped belts: These come with a fabric cover, and after the initial installation procedure, the cover starts to stretch and the belt will loose some tension. The following is the recommended procedure for running these belts. 1 Initial Tension – as the above installation procedure has already set the drive to run for the first time on new belts, that is called the NEW tension setting. This setting is typically higher than used belts, to allow for a rapid stretch in the fabric cover, and this causes a loss in overall tension. The tension could drop in an initial 2 – 24 hours significantly. This is normal for NEW belt drives, and is referred to as initial ”Tension Decay”. 2 Retension 1 - the drive will need to be stopped, and then set up to reset the tension. Once again, ensure ALL safety procedures are followed. Using the tools in the maintenance procedure reset the drive belt tensions to the USED figure as stated for each type of tool. The belts now have tension applied to the Tension members, which will heat up as they reach their power transmission potential and will see slight elongation. Over 24-48 hours the tension will drop below the USED, 3 Retension 2 – for the second retension the drive needs to be stopped and tension reset again to the USED, the drive should now be ”Tension Stable” for the next 1-3 months depending on environment and load factors.
Cushion rubber
Tension members
Cushion rubber
Wrapping fabric
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SKF XP Wrapped belts:
SKF CRE belts:
These come with a fabric cover, but there is a major advantage in the manufacture of this product. The belts are manufactured in a process that removes most of the initial stretch in both the fabric cover and the cords. The following is the recommended procedure for the running of these XP series belts.
These come with no fabric cover, but have exposed flanks, and a cogged bottom profile (for better flexibility), so the process for the tension is very similar to the XP series belts. The following is the recommended procedure for the running of these CRE belts.
1 Initial Tension – as the above installation procedure has already set the drive to run for the first time on new belts that is call the NEW tension setting. This setting must be selected for the XP belts – this is higher than normal V belts in wrapped section. The tension can be seen to drop slowly in this type of belt, with retension requirements from 2 hours to 14 days. Tension drop value seen is less than the typical cord elongation seen in standard wrapped belts. 2 Retension 1 – the drive will need to be stopped, and then set up to reset the tension. Ensure safety procedures are followed. Using the tools in the maintenance procedure reset the drive belt tensions to the USED figure stated for each type of tool for the SKF XP series belts. The belts now have tension applied to the Tension members, which will heat up as they reach their power transmission potential and will see a slight elongation. Over 1-3 months it is recommended to check the tension and reset to the USED - if required.
Transversely oriented fibre mixture of polychloroprene Cushion rubber
1 Initial Tension – as the above installation procedure has already set the drive to run for the first time on new belts that is called the NEW tension setting. This setting must be selected for the CRE (Cogged Raw Edge) belts – this is higher than normal V belts in wrapped section. The tension can be seen to drop slowly in this type of belt, with retension requirements from 2 hours to 24 hours. Tension drop value seen is less than the typical cord elongation seen in standard wrapped belts. 2 Retension 1 – the drive will need to be stopped, and then set up to reset the tension. Ensure safety procedures are followed. Using the tools in the maintenance procedure reset the drive belt tensions to the USED figure stated for each type of tool for the SKF CRE series belts. The belts now have tension applied to the Tension members, which will heat up as they reach their power transmission potential and will see a slight elongation. Over 1-3 months it is recommended to check the tension and rest to the USED if required.
Backside fabric
Cushion rubber Tension members
Tension members Transversely oriented fibre mixture of polychloroprene
Cushion rubber
Wrapping fabric
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Cushion rubber
6 Appendix The following pages are the technical and supplementary data sheets offered for the installation of V Belt drives.
I.
Trouble Shooting guide . . . . . . . . . . . . . . . . . . . . . . . . 10
II.
Taper Bush Installation Instructions . . . . . . . . . . . . . . . 11
III. Taper Bush Tightening torque and capacities. . . . . . . . 12 IV. V Belt Installation and maintenance – general information – 2 page. . . . . . . . . . . . . . . . . . . . 13 V.
Tensioning methods – 6 page. . . . . . . . . . . . . . . . . . . . 15
VI. Calculating belt Tension – 2 page. . . . . . . . . . . . . . . . . 21 VII. V Belt Pulley Torque Check & V Belt Tension Setting Check Chart – User Completed reference. . . . . . . . . . . . . . . . 23
SKF Power transmission belts
For more information: SKF BELT DESIGN MANUAL PUB PT/P1 06875 EN
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Appendix I
Troubleshooting guide
Problem
Possible causes
Solution
Belts mismatched
Used and new belts mixed
Replace with new set
Misaligned drive
Belts are progressively tighter from one side to the other. Realign pulleys.
Worn or badly machined pulley grooves
Replace or rework the pulleys
Belts undertensioned
Rotate drive to get all belts slack on bottom side. Retension to required value.
Improper belt installation
Belt levered over pulley. Follow installation instructions.
Drive undersized
Check drive design
Drive blocked
Remove cause
Resonant condition
Change drive dimensions (increase/decrease centre distance), use outside ”kissing” idler or inside idler on belt slack side.
High shock load
Increase tension. Use SKF banded belts.
Pulley not balanced
Provide dynamically balanced pulleys.
Improper outside idler size or position
Follow instructions on how to work with idlers.
Pulley diameter too small
Belt flexing issue. Change pulley according to minimum diameter recommendations.
Excessive heat
Remove source of heating. Use raw edge belts which resist higher temperatures. Check tension. Too loose belts will slip and cause heat.
Chemical attack
Provide adequate protection
Poor drive alignment
Realign pulleys
Incorrect belt/pulley groove section
Match belt and pulley
Excessive wear of pulleys
Replace or rework the pulleys
Too low tension on belts
Increase belt tension
Belt hitting guard frame
Remove cause
Starting torque too high, overloaded drive
Check drive design and redesign
Excessive pulley groove wear
Replace or rework grooves
Poor pulley alignment
Realign drive
Belt tension too low
Increase belt tension
Drive undertensioned
Tension properly
Drive overload
Redesign the drive
Pulleys worn (belt bottom in groove)
Replace or rework grooves
Excessive oil or grease
Provide better shielding on drive
Belts fail shortly after fitting
Belt vibrations
Belts break and cracks
Belts turn over
Belts wear rapidly
Belts slip
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Appendix II
Taper bushing Installation Instructions Assembly 1 Clean contact surfaces and ensure they are free from grease for shaft, taper bushing and taper-bored component. 2 Insert bushing into component and match holes (not threads). 3 Lightly oil screws and insert into holes that are threaded on the component side. Do not tighten yet. 4 Slip bushing and component onto shaft and align in desired position. Note that bushing will grip shaft first and component will move onto bushing. If using a key, fit it in the shaft keyway first. There should be atop clearance between the key and the bushing keyway. 5 Tighten the screws alternately and uniformly in accordance with the recommended torques (†tables 1A, 1B, page 12). 6 Fill the empty holes with grease to prevent corrosion. 7 Check the screw tightening torques after the drive has been operating under load for a short period (half to one hour). Removal 1 Loosen all screws. Remove one or two depending on size, leaving at least one to keep the bushing in the component. 2 Oil thread and insert into jacking off hole(s) on bush. 3 Tighten the screws alternately and uniformly until the bushing disengages. 4 Remove bushing and component from shaft.
Fig. 1 FOR installation INSTALLATION For
1008 to 3030*
3535 to 6050
7060 to 10085
12100 FOR REMOVAL ONLY
For removal only
* Sizes 1008 - 3030 may be supplied in either 3 hole or 4 hole. There is no difference in their respective performance characteristics.
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Appendix III
Taper Bush Tightening Torque Table 1A Bush Size
1008
1108
1210
1215
1610
1615
2012
2517
2525
3020
3030
3525
Screw tightening torque (Nm)
5,6
5,6
20
20
20
20
30
50
50
90
90
112
1,200 Max transmissable torque (lbf-in)*
1,300
3,600
3,550
4,300
4,300
7,150
11,600
11,300
24,000
24,000
44,800
Max transmissable torque (Nm)*
113
146
406
401
485
485
807
1310
1270
2711
2711
5061
Set screw size (BSW) (inch)
1/4x1/2
1/4x1/2
3/8x5/8
3/8x5/8
3/8x5/8
3/8x5/8
7/16x7/8 1/2x1
1/2x1
1/2x1
5/8x1-1/4 5/8x1-1/4
Set Screw Qty
2
2
2
2
2
2
2
2
2
2
2
3
Table 1B Bush Size
3535
4030
4040
4535
4545
5040
5050
6050
7060
8065
10085
120100
Screw tightening torque (Nm)
115
170
170
190
190
270
270
883
883
883
1547
1547
44,800 Max transmissable torque (lbf-in)*
77,300
77,300
110,000 110,000 126,000 126,000 282,000 416,000 456,000 869,000 1,520,000
Max transmissable torque (Nm)*
5061
8700
8700
12400
Set screw size (BSW) (inch) Set Screw Qty
14200
31861
47001
51521
98183
171736
5/8x1-1/4 1/2x1-1/2 1/2x1-1/2 5/8x1-3/4 5/8x1-3/4 3/4x2
7/8x 2-1/4
1-1/4x 3-1/2
1-1/4x 3-1/2
1-1/4x 3-1/2
1-1/4x 3-1/2
1-1/4x 3-1/2
3
3
3
4
4
4
6
3
3
3
12400
3
14200
3
* Torque values shown are for a service factor of 1.00, and must not be exceeded. For heavy shock of service applications, the torque capacity must be reduced accordingly. (Refer to www.skfptp.com for 足further information.)
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Appendix IIII
Installation and maintenance Fig. 2
All SKF V-belts are produced to be set free, i.e. you can take any belt of the same designation from the shelf and put it on a multiple groove drive. Proper tensioning will compensate small length deviations and make all belts carry equal load on the drive.
Fig. 3
b
Before installing a new belt, make sure that:
b
b
1 Pulleys are properly aligned. Maximum allowable misalignment b is 0,3° or 5 mm / 1 m of centre distance. Values greater than those listed will reduce the belt service life and cause edge wear. Misalignment is represented by the ways shown in fig. 2. A straight edge should be used to check proper alignment as in fig. 3. A more precise way to check alignment, particularly over long distances, is the SKF Belt Alignment Tool (†fig. 4).
Fig. 4
2 Make sure that all pulley grooves are of the same size. Uneven wear of grooves causes belts to run on different diameter levels in the pulley. This generates excessive slip of the belts on one side and has an effect similar to mismatched belts on the other side (†fig. 5).
Fig. 5
d1
d2
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Appendix IV General advice is to briefly inspect pulleys at every belt change but closely inspect and possibly replace at every third belt change. Use an SKF pulley gauge († fig. 6) to check pulley wear. Pulleys should be replaced when more than 0,8 mm is detected between template and groove. 3 Never mix different brands or belt types on the same drive. Belt lengths can differ from one manufacturer to another and different materials can have significantly different values for the coefficient of thermal contraction. SKF also does not recommend mixing new and used belts as it may result in uneven load distribution and premature belt failure. 4 Never force belts over the pulley edge, since this may damage the surface and initiate a crack, which will weaken the belt and cause premature belt failure. Properly slack off and take up the drive until belts are easily placed in the grooves. 5 Do not rely on belt dressings to eliminate belt slippage. Belt dressings can temporarily increase friction between the belt and pulley. However, this is always a temporary fix until the cause of slippage can be identified and corrected. 6 Tension belts according to SKF tensioning recommendations. Refer to Tensioning section on pages 15 to 17 to review tensioning equipment available. Please note, that incorrect belt tension will cause premature belt failure. A good practice is to apply slightly higher, rather than lower, tension to the belt. General experience shows that an under-tensioned V-belt is the major cause of power loss and premature belt failure. However, excessive tension may cause premature bearing failure. SKF recommends checking belt tension after the first 48 hours of continuous use and rechecking belt tension 3 to 4 times per year.
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Fig. 6
Appendix V
Tensioning methods Tensioning with the SKF belt tension tester These testers provide a simple way to determine belt tension. It is very useful in cases where no technical drive data is known which makes it impossible to calculate the appropriate tension. Table 1 gives general tensioning values for a particular belt cross section in relation to the pulley diameter. There are three testers (gauges) that cover most of the V-belt range: Gauge 1 – range: 15–70 kg Gauge 2 – range: 50–150 kg Gauge 3 – range: 150–300 kg Instructions 1 Select the appropriate tester from table 1. 2 With the indicator arm down, place the tester parallel to the side of one belt along the mid section of the span length. 3 Holding the rubber finger loop, press down on the belt. 4 Stop when you feel and hear the ”click”. 5 Remove tester and read the belt tension by observing the point where the top surface of the indicator arm crosses the numbered scale on the tester body († fig. 7).
Table 1 Metric dimension Section
Wrapped belt tension Initial Run in new belt used belt
Smallest pulley diameter
Section
Cogged belt tension Initial Run in new belt used belt
–
kg
mm
–
kg
A
15 20 31
11 15 25
≤80 80–100 101–132
AX
20 25 41
15 20 31
B
31 41 51
25 31 41
≤125 126–160 161–200
BX
46 51 61
36 41 46
C
71 82 92
51 61 71
≤200 201–250 251–355
CX
82 92 102
61 71 82
SPZ, 3V
20 25 36
15 20 25
≤71 72–90 91–125
XPZ, 3VX
25 31 41
20 25 31
SPA
36 41 51
25 31 41
≤100 101–140 141–200
XPA
41 51 61
31 41 46
SPB, 5V
66 71 92
51 56 71
≤160 161–224 225–355
XPB, 5VX
71 87 102
56 66 82
SPC
102 143 183
82 112 143
≤250 251–355 356–560
XPC
143 163 194
112 122 153
SPZ-XP, 3V-XP
22 28 40
17 22 28
≤ 71 72 – 90 91 – 125
SPA-XP
40 45 56
28 34 45
≤ 100 101 - 140 141 - 200
SPB-XP, 5V-XP
73 78 101
56 62 78
≤ 160 161 – 224 225 – 355
SPC-XP
112 157 201
90 123 157
≤ 250 251 - 355 356 - 560
Fig. 7 Rubber finger loop Indicator arm Scale
Indicator arm crosses the scale
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Appendix V Fig. 8
Fig. 9
Span length
Small O ring
Deflection force scale
Deflection
16mm/ 1000mm span
Large O ring
Span length scale
Table 2 Tension values Section
Smallest pulley diameter
Speed range
Belt deflection force Un–cogged belts Cogged belts New Used run- New Used runbelt in belt belt in belt
Section
Smallest pulley diameter
Speed range
Belt deflection force Un–cogged belts Cogged belts New Used runNew Used runbelt in belt belt in belt
–
mm
r/min
kg
–
mm
r/min
kg
Z, ZX
40–60
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
0,7 0,8 1,1 1,1
0,5 0,5 0,8 0,8
0,8 0,9 1,3 1,3
0,5 0,6 0,9 0,9
110–170
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
2,1 1,6 2,6 2,2 3,1 2,7
1,4 1,1 1,7 1,4 2,0 1,8
2,4 2,0 2,9 2,5 3,2 2,9
1,6 1,3 2,0 1,7 2,2 2,0
1 000–2 500 2 501–4 000 500–1 740 1 741–3 001 500–1 740 1 741–3 001
– – 7,3 6,5 9,0 8,4
– – 4,9 4,3 6,0 5,6
5,9 3,3 8,5 7,7 9,9 9,6
3,9 2,1 5,7 5,3 6,6 6,5
200–850 851–1 500 200–850 851–1 500
19,0 15,4 22,8 20,3
12,8 10,4 15,3 13,6
– – – –
– – – –
860–2 500 2 501–4 000 860–2 500 2 501–4 000 860–2 500 2 501–4 000
– – 3,1 2,6 3,7 3,4
– – 2,0 1,7 2,5 2,3
2,8 2,4 4,1 3,5 4,8 4,2
1,9 1,6 2,7 2,4 3,3 2,8
SPZ–XP
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
2,7 2,3 3,8 3,4 3,8 3,5
1,8 1,4 2,0 2,2 2,5 2,3
– – – – – –
– – – – – –
500–1 740 1 741–3 000 500–1 740 1 741–3 000
6,5 5,4 8,1 7,1
4,4 3,7 5,4 4,8
8,4 6,7 9,1 8,3
5,7 4,6 6,1 5,6
SPA–XP
200–850 851–1 500 200–850 851–1 500
14,3 12,1 17,4 14,6
9,6 8,2 11,7 9,9
– – – –
– – – –
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
4,6 4,1 5,5 4,9 6,9 6,9
3,0 2,8 3,7 3,3 4,6 4,6
– – – – – –
– – – – – –
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
2,3 1,9 3,1 2,8 3,1 2,9
1,5 1,1 1,7 1,8 2,1 1,9
2,3 1,9 2,9 2,8 3,3 3,1
1,6 1,3 1,9 1,8 2,2 2,0
860–2 500 2 501–4 000 860–2 500 2 501–4 000 860–2 500 2 501–4 000
7,7 7,4 9,9 8,8 11,7 10,1
5,1 4,9 6,6 5,9 7,9 6,7
– – – – – –
– – – – – –
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
3,8 3,4 4,5 4,1 5,7 5,7
2,5 2,3 3,0 2,7 3,8 3,8
4,3 3,9 5,2 4,7 6,6 5,9
2,9 2,6 3,5 3,1 4,3 3,9
500–1 740 1 741–3 000 500–1 740 1 741–3 000
15,9 16,1 18,1 21,0
10,7 10,7 12,1 14,0
– – – –
– – – –
860–2 500 2 501–4 000 860–2 500 2 501–4 000 860–2 500 2 501–4 000
6,3 6,1 8,2 7,3 9,7 8,3
4,3 4,1 5,5 4,9 6,5 5,5
7,3 7,0 9,4 8,7 10,4 9,5
4,9 4,7 6,2 5,8 6,9 6,3
– – – – – –
500–1 740 1 741–3 000 500–1 740 1 741–3 000
13,1 13,3 15,0 17,4
8,8 8,9 10,0 11,6
15,1 15,3 17,2 19,9
10,1 10,1 11,4 13,3
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
– – 2,0 1,7 2,8 2,6
– – 1,4 1,2 1,9 1,7
1,9 1,7 2,4 2,1 3,1 2,8
1,3 1,1 1,6 1,4 2,0 1,9
61–over A, AX
75–90 91–120 121–over
B, BX
85–105 106–140 141–over
C,CX
175–230 231–over
D
305–400 401–over
SPZ, XPZ
56–79 80–95 96–over
SPA, XPA
71–105 106–140 141–over
SPB, XPB
107–159 160–250 251–over
SPC, XPC
200–355 356–over
3V, 3VX
55–60 61–90 91–over
16
5V, 5VX
171–275 276–over 8V
315–430 431–over 56–79 80–95 96–over 71–105 106–140 141–over
SPB–XP
107–159 160–250 251–over
SPC–XP
200–355 356–over
3V–XP
55–60 61–90 91–over
5V–XP
110–170 171–275 276–over
8V–XP
315–430 431–over
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
2,4 2,1 3,4 3,1
1,6 1,4 2,3 2,1
– – – – – –
1 000–2 500 2 501–4 000 500–1 740 1 741–3 001 500–1 740 1 741–3 001
8,8 7,8 10,9 10,2
6,0 5,2 7,2 6,8
– – – – – –
– – – – – –
200–850 851–1 500 200–850 851–1 500
23,0 18,6 27,6 22,3
15,4 12,5 18,5 15,0
– – – –
– – – –
Appendix V
Tensioning with the SKF pen tester
Fig. 10 Display window
This gauge is available to determine the deflection force [kg] required to set and maintain V-belt tension. Table 2 lists the required force needed to deflect a belt in mid-span relative to pulley diameter and speed. 1 Measure the span length († fig. 8) 2 Position the bottom of the large O ring on the pen scale at the measured span length († fig. 9) 3 Set the small O ring on the deflection force scale to zero 4 Place the tension tester squarely on one belt at the centre of the span length († fig. 9) and apply downward force to the plunger until the bottom of the large O-ring is even with the next belt or with the bottom of a straight edge laid across the pulleys. 5 Remove the tension tester and read the force applied with the values given in the tables. The force should be between the minimum and the maximum shown. The maximum value shown is for new belts, which will allow for anticipated tension loss. Used belts should be maintained at the minimum values indicated in the tables.
Optical sensor Keypad
LED aiming beam Plug in sensor cable
Tensioning with the SKF Belt Frequency Meter The SKF Belt Frequency Meter is used for checking the tension by means of belt natural frequency measurements († fig. 10). Tension measurements are presented in hertz [Hz] or in newton [N], if the drive parameters are entered. Advantages • Precise and repeatable measurements • Non-contact optical head with LED beam for easy pointing to belt surface • Easy-to-use • Wide tension range (10–400 Hz) • Extremely fast response allows quick tension checks on multiple belt drives
Instructions 1 Press ON/OFF to switch meter ON. 2 Press button UP or DOWN to select display mode indicated on left side of the display. 3 In case newton [N] mode is selected, then: i. Enter belt specific mass [g/m] provided with operating instruction. ii. Enter span length [m] 4 Hold the optical head up to the belt span and strum the belt slightly to make it vibrate. 5 Measurement is automatically performed. Read-out is given in herz or in newton depending on selected display mode.
Can be used in two different ways: a Technical data of the drive is not known and therefore the appropriate tension cannot be calculated. In such cases, refer to general tension values recommended for the particular belt in tables 3A, 3B and 3C. a Drive data is known. The tensioning value can be calculated by the drive design program or by a belt tension formula. Simply measure the strand tension in the belt and compare it with the calculated value.
17
Appendix V Table 3A Wrapped V, wedge XP and banded belts Section
Smallest pulley diameter
Speed range
–
mm
r/min
N
Z
40–60
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
104 121 174 174
69 81 116 116
0,051
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
332 254 391 332 469 411
222 169 261 222 313 274
0,115
860–2 500 2 501–4 000 860–2 500 2 501–4 000
469 391 567 528
313 261 378 352
0,193
500–1 740 1 741–3 000 500–1 740 1 741–3 000
1 017 841 1 251 1 115
678 561 834 743
0,320
0,417
200–850 851–1 500 200–850 851–1 500
2 210 1 877 2 698 2 268
1 473 1 251 1 799 1 512
0,69
0,870
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
338 262 383 415 477 438
226 175 255 276 318 292
0,076
n/a
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
575 524 696 628 872 876
383 349 464 418 581 584
0,134
860–2 500 2 501–4 000 860–2 500 2 501–4 000 860–2 500 2 501–4 000
978 941 1 255 1 116 1 496 1 275
652 627 837 744 997 850
0,223
0,268
500–1 740 1 741–3 000 500–1 740 1 741–3 000
2 026 2 043 2 305 2 671
1 350 1 362 1 537 1 781
0,354
0,394
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
313 274 430 391
209 182 287 261
0,076
0,099
500–1 740 1 741–3 000 500–1 740 1 741–3 000
1 134 997 1 369 1 291
756 665 912 860
0,223
0,272
200–850 851–1 500 200–850 851–1 500
2 933 2 386 3 520 3 129
1 955 1 590 2 346 2 086
0,504
0,654
61–over A
75–90 91–120 121–175
B
105–140 141–220
C
175–230 231–400
D
305–400 401–510
SPZ
56–79 80–95 96–over
SPA
71–105 106–140 141–over
SPB
107–159 160–250 251–over
SPC
200–355 356–over
3V
61–90 91–175
5V
171–275 276–500
8V
315–430 431–570
Belt tension per Mass single belt* New belt Used run- Single in belt belt
Section
Smallest pulley diameter
Speed range
–
mm
r/min
N
SPZ-XP
56–79
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
372 288 421 457 525 482
249 193 281 304 350 321
0,079
n/a
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
633 576 766 691 959 964
421 384 510 460 639 642
0,122
n/a
860–2 500 2 501–4 000 860–2 500 2 501–4 000 860–2 500 2 501–4 000
1076 1035 1381 1228 1646 1403
717 690 921 818 1097 935
0,202
n/a
500–1 740 1 741–3 000 500–1 740 1 741–3 000
2229 2247 2536 2938
1485 1498 1691 1959
0,350
n/a
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
344 301 473 430,1
230 200 315,7 287,1
0,079
n/a
500–1 740 1 741–3 001 500–1 740 1 741–3 001
1247,4 1096,7 1505,9 1420,1
831,6 731,5 1003,2 946
0,202
n/a
200–850 851–1 500 200–850 851–1 500
3226,3 2624,6 3872 3441,9
2150,5 1749 2580,6 2294,6
0,520
n/a
Belt in a band**
kg/m n/a
80–95 95–over
0,150 SPA-XP
71–105 106–140 141–over
0,260
SPB-XP 107–159 160–250 251–over SPC-XP 200–355 356–over 3V-XP
61–90 91–175
5V-XP
171–275 276–500
0,155 8V-XP
315–430 431–570
Belt tension per Mass single belt* New belt Used run- Single in belt belt
Belt in a band**
kg/m
The values listed in the tables on the following pages provide a guideline for belt tensioning. More accurate values for your specific belt drive can be obtained from belt drive calculations on skfptp.com. * Multiply ** Multiply
18
the belt tension required for a single belt by the number of belts in the banded belt unit to get the total tension to apply. the mass of one belt in a band by the number of belts in the banded belt unit to get the total mass to apply.
Appendix V Table 3B Cogged raw edge V, wedge and banded belts Section
Smallest pulley diameter
Speed range
Belt tension per single belt* New belt Used run-in belt
Mass Single belt
–
mm
r/min
N
kg/m
ZX
40–60
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
119 139 199 199
80 93 133 133
0,051
n/a
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
372 293 450 391 508 450
248 196 300 261 339 300
0,115
0,153
860–2 500 2 501–4 000 860–2 500 2 501–4 000 860–2 500 2 501–4 000
430 372 626 547 763 645
287 248 417 365 508 430
0,193
0,225
500–1 740 1 741–3 000 500–1 740 1 741–3 000
1 310 1 056 1 408 1 291
873 704 939 860
0,320
0,398
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
362 299 438 418 499 469
241 199 292 279 332 313
0,076
n/a
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
657 598 796 718 997 897
438 399 531 478 665 598
0,134
0,156
860–2 500 2 501–4 000 860–2 500 2 501–4 000 860–2 500 2 501–4 000
1 116 1 075 1 435 1 330 1 596 1 455
744 717 957 886 1 064 970
0,223
0,279
500–1 740 1 741–3 000 500–1 740 1 741–3 000
2 313 2 333 2 632 3 050
1 542 1 555 1 755 2 034
0,354
0,548
1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000 1 000–2 500 2 501–4 000
293 254 372 332 469 430
196 169 248 222 313 287
0,076
0,102
1 000–2 500 2 501–4 000 500–1 740 1 741–3 001 500–1 740 1 741–3 001
899 489 1 310 1 212 1 525 1 486
600 326 873 808 1 017 991
0,223
0,252
61–over AX
75–90 91–120 121–175
BX
85–105 106–140 141–220
CX
175–230 231–400
XPZ
56–79 80–95 96–over
XPA
71–105 106–140 140–over
XPB
107–159 160–250 251–over
XPC
200–355 356–over
3VX
55–60 61–90 91–175
5VX
110–170 171–275 276–400
Belt in a band**
The values listed in the tables on following pages provide a guideline for belt tensioning. More accurate values for your specific belt drive can be obtained from belt drive calculations on skfptp.com. * Multiply ** Multiply
the belt tension required for a single belt by the number of belts in the banded belt unit to get total tension to apply. the mass of one belt in a band by the number of belts in the banded belt unit to get total mass to apply.
19
Appendix V Table 3C Timing belts
Timing belts Section
Belt tension New belt
–
–
N
HiTD
5M 9 5M 15 5M 25 8M 20 8M 30 8M 50 8M 85 14M 40 14M 55 14M 85 14M 115 14M 170
99 174 311 372 593 1 037 2 044 1 297 1 912 3 142 4 480 7 139
STD
S8M20 S8M30 S8M50 S8M85 S14M40 S14M55 S14M85 S14M115 S14M170
390 620 1 110 2 030 1 340 1 925 3 165 4 465 6 975
Used run-in belt
Mass –
–
N
71 124 222 266 424 741 1 460 926 1 366 2 244 3 200 5 099
0,037 0,061 0,102 0,128 0,192 0,32 0,545 0,429 0,59 0,911 1,233 1,823
Timing
279 443 793 1 450 957 1 375 2 261 3 189 4 982
0,111 0,167 0,278 0,473 0,462 0,634 0,981 1,327 1,962
XL 025 XL 037 LO50 LO75 L 100 H075 H100 H150 H200 H300 XH 200 XH 300 XH 400 XXH 200 XXH 300 XXH 400
13 24 51 87 122 220 311 485 667 1 045 907 1 428 2 019 1 130 1 748 2 478
Arc of contact power correction factor C3 D–d CC
Arc of contact on small pulley
Arc of contact correction factor C3
mm
deg.
–
0,00 0,05 0,10
180 177 174
1,00 0,99 0,99
0,15 * 0,20 0,25
171 169 166
0,98 0,97 0,97
0,30 0,35 0,40
163 160 157
0,96 0,95 0,94
0,45 0,50 0,55
154 151 148
0,93 0,93 0,92
0,60 0,65 0,70
145 142 139
0,91 0,90 0,89
0,75 0,80 0,85
136 133 130
0,88 0,87 0,86
0,90 0,95 1,00
127 123 120
0,85 0,83 0,82
1,05 1,10 1,15
117 113 100
0,81 0,80 0,78
1,20 1,25 1,30
107 104 101
0,77 0,75 0,73
1,35 1,40
97 93
0,72 0,70
d Small pulley diameter CC Centre to centre distance
20
Belt tension New belt
kg/m
Table 4
* D Large pulley diameter
Section
Used run-in belt
Mass kg/m
11 20 41 70 98 176 249 388 534 836 726 1 142 1 615 904 1 398 1 982
0,014 0,02 0,043 0,065 0,087 0,084 0,112 0,168 0,223 0,335 0,572 0,858 1,144 0,809 1,213 1,617
Appendix VI
Calculating belt tension
Insufficient belt tension will cause the belt to slip, which consequently generates heat, high belt temperatures and premature ageing of the belt. Degradation of the rubber compound, caused by excessive heat, will have a significant impact on the service life of a belt. When the tension is too high, the belt will not slip, but this will have a negative impact on the service life of the bearings and the belt. There are two values that must be considered when tensioning a belt: a Tused (run-in) is minimum tension on the belt that ensures minimum slip on the drive. Belt tension should ideally not drop below this value during the entire belt service life. b Tnew (initial) is maximum tension in the belt, used to initially tension a new belt. Tnew normally decreases during the first hours of operation releasing initial high bearing loads.
General tensioning values
Tensioning values for general tensioning purposes are provided by the operating manual for selected tensioning tools. The values represent the ”worst case” drives and as such, tend to be higher than the values calculated for a specific drive.
Calculating tension values
In cases where all drive data is available, it is possible to calculate the required tension instead of using the general tensioning values. To calculate tension values, the following procedure should be used: a Find the minimum required strand tension for used run-in belts using the formula:
where v = belt speed [m/s] d = pulley datum diameter [mm] n = speed of driver pulley [r/min] (2,2 – C3) Pd M v2 Tused = 510 ————— + —— C3 N v 1,11 where Tused = minimum required static tension in one strand of the belt [N] C3 = arc of contact correction factor († table 4) Pd = design power [kW] N = number of belts on the drive v = belt speed [m/s] M = belt weight per unit [kg/m] († tables 3A, 3B, 3C)
where Fd used, Fd new = deflection force for a used run-in respectively a new belt [kg] Tused, Tnew = required strand tension for a used run-in respectively a new belt N = number of belts (for single V-belt N = 1) or number of belts in a band. K = belt modulus factor († table 5) = span length of the belt [m] Sp L = reference length of the belt [m] d If the SKF Belt Frequency Meter is used to tension the drive, take value Tnew (Tused) and directly compare it with the readings from the tester.
b Increase Tused value by 50% to get initial required tension on a new belt Tnew Tnew = 1,5 Tused c If the SKF pen tester is used to tension the drive, calculate belt deflection force. For single V-belts and single units of banded and ribbed belts: t Tused N N K Sp y Fd used = 0.102 ¥s ——— + ——— s v 16 L b
Table 5 Belt modulus factor Section
K
Z, ZX
2,67
A, AX
2,94
B, BX
3,87
C, CX
5,87
D
8,01
SPZ, XPZ, 3V, 3VX
2,89
t Tused N y Fd used = 0.102 ¥s ——— + N K s v 16 b
SPA, XPA
3,12
SPB, XPB, 5V, 5VX
4,01
SPC, XPC
6,23
8V
7,57
t Tnew N N K Sp y Fd new = 0.102 ¥ s ——— + ——— s v 16 L b For multiple V-belts or matched sets of banded and ribbed belts:
t Tnew N y Fd new = 0.102 ¥s ——— + N K s v 16 b
dn v = ———– 19 100
21
Appendix VI
Tensioning by means of belt elongation
Table 6 Length addition for 1 000 mm of belt strand Single belt, A banded belt
This method is used when installing new or used run-in banded V-belt sets or where individual belts require so much force that other tensioning methods are not practical.
1 Determine strand tension (New, Used). To do this, use general strand tension values provided in the SKF Belt Frequency Meter manual or calculate the required static strand tension. 2 Fit the belt on both pulleys with no tension. 3 Draw two lines on the back of the belt 1 000 mm apart. 4 Increase the distance between the two lines according to data provided in table 6.
Required static strand tension (N)
Instructions
If more appropriate, the following approach could be used.
Note: If you are re-tensioning a used belt, decrease the centre distance until there is no tension on the belt, then you can tape the outside.
22
C
D
SPA SPA-XP
SPB SPB-XP 5V 5V-XP
SPC SPC-XP
8V 8V-XP
–
Elongation per 1 000 mm of belt strand (mm)
200 250 300 350 400
3,4 4,3 5,1 6,0 6,8
1,5 1,8 2,2 2,6 2,9
– – – – 2,4
– – – – –
3,0 3,8 4,5 5,3 6,0
– – – – 2,1
– – – – –
– – – – –
450 500 550 600 650
7,7 8,5 9,4 10,2 11,1
3,3 3,7 4,0 4,4 4,8
2,7 3,0 3,3 3,6 3,8
– – – 3,2 3,4
6,8 7,5 8,3 9,0 9,8
2,6 3,1 3,6 4,1 4,6
– – 1,9 2,2 2,5
– – – – –
700 750 800 900 1 000
11,9 12,8 – – –
5,2 5,5 5,9 6,6 7,4
4,1 4,4 4,7 5,3 5,9
3,7 4,0 4,2 4,7 5,3
10,5 11,3 – – –
5,1 5,6 6,1 7,0 7,9
2,9 3,2 3,6 4,1 4,7
– – – – –
1 200 1 400 1 600 1 800 2 000
– – – – –
8,8 10,3 11,8 – –
7,1 8,3 9,5 – –
6,3 7,4 8,4 9,5 10,6
– – – – –
9,5 11,2 12,9 14,6 16,2
5,8 6,8 7,9 9,0 10,0
3,6 4,6 5,6 6,6 7,6
2 250 2 500 2 750 3 000 3 250
– – – – –
– – – – –
– – – – –
11,9 13,2 14,5 – –
– – – – –
18,3 20,4 22,4 – –
11,3 12,7 14,0 15,3 16,6
8,7 9,9 11,0 12,2 13,3
3 500 3 750 4 000 4 250
– – – –
– – – –
– – – –
– – – –
– – – –
– – – –
– – – –
14,5 15,6 16,8 17,9
Table 7 Belt length multiplier Single belt, A banded belt
Required static strand tension (N)
1 Use a tape measure to measure the outside circumference of the belt. 2 Using the length multiplier from table 7 and calculate the length of the belt under adequate tension. 3 Increase the drive centre distance until the tape measure reaches the calculated length.
B
B
C
D
SPA SPA-XP
SPB SPB-XP 5V 5V-XP
SPC SPC-XP
8V 8V-XP
–
Belt length multipliers
200 250 300 350 400
1,0034 1,0043 1,0051 1,0060 1,0068
1,0015 1,0018 1,0022 1,0026 1,0029
– – – – 1,0024
– – – – –
1,0030 1,0038 1,0045 1,0053 1,0060
– – – – 1,0021
– – – – –
– – – – –
450 500 550 600 650
1,0077 1,0085 1,0094 1,0102 1,0111
1,0033 1,0037 1,0040 1,0044 1,0048
1,0027 1,0030 1,0033 1,0036 1,0038
– – – 1,0032 1,0034
1,0068 1,0075 1,0083 1,0090 1,0098
1,0026 1,0031 1,0036 1,0041 1,0046
– – 1,0019 1,0022 1,0025
– – – – –
700 750 800 900 1 000
1,0119 1,0128 – – –
1,0052 1,0055 1,0059 1,0066 1,0074
1,0041 1,0044 1,0047 1,0053 1,0059
1,0037 1,0040 1,0042 1,0047 1,0053
1,0105 1,0113 – – –
1,0051 1,0056 1,0061 1,0070 1,0079
1,0029 1,0032 1,0036 1,0041 1,0047
– – – – –
1 200 1 400 1 600 1 800 2 000
– – – – –
1,0088 1,0103 1,0118 – –
1,0071 1,0083 1,0095 – –
1,0063 1,0074 1,0084 1,0095 1,0106
– – – – –
1,0095 1,0112 1,0129 1,0146 1,0162
1,0058 1,0068 1,0079 1,0090 1,0100
1,0036 1,0046 1,0056 1,0066 1,0076
2 250 2 500 2 750 3 000 3 250
– – – – –
– – – – –
– – – – –
1,0119 1,0132 1,0145 – –
– – – – –
1,0183 1,0204 1,0224 – –
1,0113 1,0127 1,0140 1,0153 1,0166
1,0087 1,0099 1,0110 1,0122 1,0133
3 500 3 750 4 000 4 250
– – – –
– – – –
– – – –
– – – –
– – – –
– – – –
– – – –
1,0145 1,0156 1,0168 1,0179
Appendix VII
V Belt Pulley Torque Check V Belt tension setting Check To enable completion of the Belt Drive assembly to the required best practice, the details of the applied torque settings and belt tension settings need to be properly documented for review. This will ensure the job is completed to the correct standards, and also allow as a check list to makes sure all items are completed - as no margin for error can be allowed (personal health and safety will be compromised otherwise).
Pulley
Taper Bush Size
Required Bolt Torque
Confirmed set bolt torque
Dr Dn
Belt position
Required Tension (from chart)
1
Actual
2
Actual
3
Actual
4
Actual
5
Actual
6
Actual
7
Actual
8
Actual
9
Actual
10
Actual
11
Actual
12
Actual
* Belt position relates - on Motor pulley, No1 is closest to the motor.
23
The Power of Knowledge Engineering Seals
Bearings and units
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Drawing on five areas of competence and application-specific expertise amassed over more than 100 years, SKF brings innovative solutions to OEMs and production facilities in every major industry worldwide. These five competence areas include bearings and units, seals, lubrication systems, mechatronics (combining mechanics and electronics into intelligent systems), and a wide range of services, from 3-D computer modelling to advanced condition monitoring and reliability and asset management systems. A global presence provides SKF customers uniform quality standards and worldwide product availability.
Ž SKF is a registered trademark of the SKF Group. Š SKF Group 2011 The contents of this publication are the copyright of the publisher and may not be reproduced (even extracts) unless prior written permission is granted. Every care has been taken to ensure the accuracy of the information contained in this publication but no liability can be accepted for any loss or damage whether direct, indirect or consequential arising out of the use of the information contained herein. PUB PT/I4 12419 EN ¡ December 2011
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