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Home V-belt drive symptoms

Power Transmission Belts

Pulleys

V-belt drive symptoms


Symptoms Probable cause Corrective action

Vorzeitiger Riemenausfall

Broken belts

Gerissener (gebrochener) Riemen
  • Under-designed drive
  • Belt rolled or pried onto the pulley
  • Object falling into drive
  • Severe shock load
  • Redesign of the drive
  • Use drive take-up when installing
  • Provide adequate guard or drive protection
  • Redesign to accommodate shock load
Belts fail to carry load, no visible reason
  • Underdesigned drive
  • Damaged tensile member
  • Worn pulley grooves
  • Center distance movement
  • Redesign of your drive
  • Follow correct installation procedure
  • Check for groove wear
Edge cord failure
  • Pulley misalignment
  • Damaged tensile member
  • Check alignment and correct
  • Follow correct installation procedure
Belt de-lamination or undercord separation
  • Too small pulleys
  • Use of too small backside idler
  • Check drive design, replace with larger pulleys
  • Increase backside idler to acceptable diameter

Severe or abnormal V-belt wear

Wear on top surface of belt

Verschleiß an oberer Riemenummantelung
  • Rubbing against guard
  • Idler malfunction
  • Replace or repair guard
  • Replace idler
Wear on top corner of belt
  • Belt-to-pulley fit incorrect (belt too small for groove)
  • Use correct belt-to-pulley combination
Wear on belt sidewalls

Verschleiß an den Flanken
  • Belt slip
  • Misalignment
  • Worn pulleys
  • Incorrect belt
  • Retention until slipping stops
  • Realign pulleys
  • Replace pulleys
  • Replace with correct belt size
Wear on bottom corner of belt
  • Belt-to-pulley fit incorrect
  • Worn pulleys
  • Use correct belt-to-pulley combination
  • Replace pulleys
Wear on bottom surface of belt
  • Belt bottoming on pulley groove
  • Worn pulleys
  • Debris in pulleys
  • Use correct belt/pulley match
  • Replace pulleys
  • Clean pulleys
Undercord cracking
  • pulley diameter too small
  • Belt slip
  • Backside idler too small
  • Improper storage
  • Use larger diameter pulleys
  • Retention
  • Use larger diameter backside idler
  • Don’t coil belt too tightly, kink or bend. Avoid heat and direct sunlight
Undercord or sidewall burn or hardening
  • Belt slipping
  • Worn pulleys
  • Underdesigned drive
  • Shaft movement
  • Retension until slipping stops
  • Replace pulleys
  • Check for center distance changes
Belt surface hard or stiff

Massive Verhärtung an der Riemenummantelung
  • Hot drive environment
  • Improve ventilation to drive
Belt surface flaking, sticky or swollen
  • Oil or chemical contamination
  • Do not use belt dressing
  • Eliminate sources of oil, grease or chemical contamination

V-belts turn over or come off drive

Involves single or Kraftbands
  • Shock loading or vibration
  • Foreign material in grooves
  • Misaligned pulleys
  • Worn pulley grooves
  • Damaged tensile member
  • Incorrectly placed flat idler
  • Mismatched belt set
  • Poor drive design
  • Check drive design
  • Shield grooves and drive
  • Realign the pulleys
  • Replace pulleys
  • Use correct installation and belt storage procedure

Problems with V-belt take-up

Kraftbands stretch unequally
  • Misaligned drive
  • Debris in pulleys
  • Broken tensile member or cord damaged
  • Realign and retension drive
  • Clean pulleys
  • Replace all belts, install properly
Single belt, or where all belts stretch evenly
  • Insufficient take-up allowance
  • Grossly overloaded or under designed drive
  • Broken tensile members
  • Check take-up
  • Redesign drive
  • Replace belt, install properly

V-belt noise

Belt squeals or chirps
  • Belt slip
  • Contamination
  • Retension
  • Clean belts and pulleys
Slapping Sound
  • Loose belts
  • Mismatched set
  • Misalignment
  • Retension
  • Install matched belt set
  • Realign pulleys so all belts share load equally
Rubbing sound
  • Guard interference
  • Repair, replace or redesign guard
Grinding sound
  • Damaged bearings
  • Replace, align & lubricate
Unusually loud drive
  • Incorrect belt
  • Incorrect Tension
  • Worn pulleys
  • Debris in pulleys
  • Use correct belt size
  • Check tension and adjust
  • Replace pulleys

Unusual vibration

Belts flopping
  • Loose belts (under tensioned)
  • Mismatched belts
  • Pulley misalignment
  • Retension
  • Align pulley
Unusual or excessive vibration
  • Incorrect belt
  • Poor machine or equipment design
  • Pulley out of round
  • Loose drive components
  • Use correct belt cross section in pulley. Use correct tooth profile and pitch in sprocket
  • Check structure and brackets for adequate strength
  • Replace with non-defective pulley
  • Check machine components and guards, motor mounts, motor, pads, bushings, brackets, etc.

Problems with Kraftbands

Tie band separation
  • Worn pulleys
  • Improper groove spacing
  • Replace pulleys
  • Use standard groove pulleys
Top of tie band frayed or worn
  • Interference with guard
  • Backside idler malfunction or damaged
  • Check guard
  • Replace or repair backside idler
Kraftband belt comes off drive repeatedly
  • Debris in pulleys
  • Misalignment
  • Clean grooves. Use single belts to prevent debris from being trapped in grooves
  • Realign drive
One or more “ribs” runs out of pulley
  • Misalignment
  • Undertensioned
  • Realign drive
  • Retension

Problems with pulleys

Broken or damaged pulley
  • Incorrect pulley installation
  • Foreign objects falling into drive
  • Excessive rim speeds
  • Incorrect belt installation
  • Do not tighten bushing bolts beyond recommended torque values
  • Use adequate drive guard
  • Keep pulley rim speeds below maximum recommended value
Severe Groove Wear
  • Excessive belt tension
  • Sand, debris or contamination
  • Do not pry belts onto pulleys
  • Retension, check drive design

Problem with other drive components

Bent or broken shaft
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  • Extreme belt overtension
  • Overdesigned drive
  • Accidental damage
  • Machine design error
  • Retension
  • Check drive design, may need to use smaller or fewer belts
  • Redesign drive guard
  • Check machine design
Broken guard interference
  • Accidental damage
  • Redesign drive guard

Hot bearings

Overtensionend v-belt
  • Severe Groove Wear
  • Incorrect belt tension
  • Replace pulleys
  • Retension
Too small pulley diameter
  • Engine manufacturers figures has not been met
  • Redesign of the drive
Hot Bearings
  • Worn grooves - belts bottoming and won’t transmit power until overtensioned
  • Improper tension
  • Replace pulleys. Tension drive properly
  • Retension
Severe Groove Wear
  • Excessive belt tension
  • Sand, debris or contamination
  • Do not pry belts onto pulleys
  • Retension, check drive design
Belt slip
  • Too low tension
  • Retension