VBelt Installation

1
V-Belt Installation Tensioning
2
Safety First

• Be sure to review and comply with all building
  and safety codes
• Disconnect and lockout the power supply

3
Inspect Drive Elements

• Inspect and replace faulty or damaged machine
  elements such as worn bearings or bent shafts

4
Relieve Belt Tension

• Loosen the drive take-up and move the sheaves
  closer together to facilitate the removal of the
  old belts and to insure installation of the new
  belts without damage

5
Inspect Drive Elements

• Sheaves should be cleaned of rust and foreign
  material

6
Inspect Sheaves

• Sheave condition and alignment are vital to
  V-Belt life performance
• Never install new belts without a thorough
  inspection of the sheaves
• Look for worn groove sidewalls, shiny sheave
  groove bottom, wobbling sheaves and damaged
  sheaves

7
Select Replacement Belts

• Never mix new and used belts on a drive
• Never mix belts from more than one manufacturer
• Always replace with the right type of belt
• Always observe belt matching limits

8
Installing New Belts

• Place the new belts on the sheaves and be sure
  that the slack of each belt is on the same side
• Do not force the belts on the sheaves by using a
  pry bar or by rolling the sheaves

9
Check Sheave Alignment

• Sheave should be mounted as close to bearing as
  possible to reduce overhung load on bearing
• The straight-edge should make contact at two
  distinct points along the outside perimeter of
  both sheaves
• V-Belt sheave alignment should be within a
  tolerance of 1/16 per 12 of drive center
  distance

10
Drive Alignment
The straight-edge should make contact at two
distinct points along the outside perimeter of
both sheaves.
Proper Off-Set Pigeon-Toed
Angle
11
V-Belt Tensioning

• Proper tensioning is the single most important
  factor necessary for long, satisfactory operation
• Too little tension will result in slippage,
  causing rapid belt and sheave wear and loss of
  productivity
• Too much tension can result in excessive stress
  on the belts, bearings and shafts

12
V-Belt Tensioning

• Tension-Finder
• A simple method to assure proper tensioning
• Easy and Accurate
• For use on individual belts or V-Bands
• Should not be used with aramid or glass cord
  belts

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V-Belt TensioningUsing the Tension-Finder

• Step 1 Install belts loosely on the drive
• Step 2 Apply enough tension to take the slack
  out of the belts

14
V-Belt TensioningUsing the Tension-Finder

• Step 3 Scribe a line on the belt using the
  Tension-Finder as a square

15
V-Belt TensioningUsing the Tension-Finder

• Step 4 Place the Start Slot over the line

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V-Belt TensioningUsing the Tension-Finder

• Step 5 With the line in the Start Slot, attach
  the spring to the belt
• For cog belts, the best place for the spring may
  be in the cog

17
V-Belt TensioningUsing the Tension-Finder

• Step 6 Scribe a line at the spring end of the
  Tension-Finder. Use this line as a reference
  point in case the spring slips off the belt

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V-Belt TensioningUsing the Tension-Finder

• Step 7 Determine the required slot for your
  drive from the table. Then keeping the
  Tension-Finder snug against the clip, tighten the
  belt until the line has moved to the designated
  slot.

19
V-Belt TensioningUsing the Tension-Finder

• Step 8 Remove Tension-Finder hardware from the
  belt, tighten mounting bolts and replace belt
  guards. Youre ready to start the drive!
• Warning!! Remove all Tension-Finder hardware from
  the belt before starting the drive.

20
V-Belt TensioningSpecial instructions for Cog
Belts

• Place the spring in a cog groove

21
V-Belt TensioningSpecial instructions for Cog
Belts

• Put a dot in the start slot. Be careful not to
  catch the pen in the slot so you dont pull the
  tip out of the pen.

22
V-Belt TensioningSpecial instructions for Cog
Belts

• Scribe a line through the dot. The line should
  extend across the width of the Tension-Finder.

23
V-Belt TensioningRecommended tensioning slots
for Tension-Finder
The recommended slot numbers will provide an
adequate level of belt tension on average drives.
If more tension is required go to a higher
slot number. For less tension go to a lower slot
number.
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V-Belt Tensioning

• Operate the drive for a few minutes to seat the
  belts in the sheave grooves. Observe the
  operation of the drive under the highest load
  condition (usually starting). A slight bowing of
  the slack side of the drive indicates adequate
  tension. If the slack side remains taut during
  the peak load, the drive is too tight.
• Check the tension on a new drive several times
  during the first 24 hours of operation, by
  observing the slack side span.

25
V-Belt Tensioning

• Keep the drive free of foreign material which
  might cause slippage or damage to the belt and
  sheave surfaces.
• If a V-Belt slips, it is too loose. Increase the
  tension by increasing the center distance.
• Never apply belt dressing as this will damage the
  belt and cause early failure.