Baixe Understanding Bearing Damage: Types, Causes, and Prevention e outras Manuais, Projetos, Pesquisas em PDF para Elementos de Sistemas de Engenharia, somente na Docsity!
Fatigue Spalling
Skill Level: Easy | Special Tools: None
Recognizing causes and types of bearing damage can help you prevent further damage
resulting in improved bearing life and performance.
Inclusion origin: Oxides or other hard inclusions in bearing steel.
Point surface origin (PSO): Debris and raised metal exceeding the lubricant film thickness.
Geometric stress concentration (GSC): Misalignment, system deflections and heavy loading.
Total bearing lock-up: Rollers skew and slide sideways.
Bearing cone (inner race) large rib face deformation: Metal flow from excessive heat generation.
Deformation
Deformation Handling Damage
Bearing cup (outer race) -face denting: Indentations from hardened driver.
Roller nicking and denting: Rough handling or installation damage.
Roller spaced nicking: Raised metal on races from contact with roller edges.
TECHTIPS
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Tapered Roller Bearing Damage
CV
Cage Damage
Rollers binding and skewing: Cage ring compressed or interfered with during installation or service.
Cage deformation: Improperly installed or dropped bearing.
Excessive Preload or Overload Damage
Bearing cone (inner race) bore polishing: Contact wear and creeping on shaft caused by lack of lubrication and cone bore contraction from excessively tight setting (preload).
Full race width fatigue spalling: caused by heavy loads creating a thin lubricant film and elevated temperatures.
Excessive End Play Damage
Scalloping: Uneven localized wear resulting from excessive end play.
Cage pocket wear: Heavy contact between rollers and cage pocket surfaces caused by bearing operating too loosely.
*Damage caused by excessive preload can appear similar to damage caused by inadequate lubrication.
Scoring
Bearing cone (inner race) large rib face scoring: ‘Welding’ and heat damage from metal-to-metal contact.
Roller end scoring: Metal- to-metal contact from breakdown of lubricant film.
Improper Fit Damage
Bearing cone (inner race) bore damage: Fractured cone due to out-of-round or oversized shaft.
The Timken team applies their know-how to improve the reliability and performance of machinery in diverse www.timken.com/aftermarket markets worldwide. The company designs, makes and markets high-performance mechanical components, including bearings, gears, belts, chain and related mechanical power transmission products and services. Stronger. Commitment. Stronger. Value. Stronger. Worldwide. Stronger. Together. | Stronger. By Design. 2-16: 29 Order No. 10308 |^ Timken ®^ is a registered trademark of The Timken Company. |^ © 2016 The Timken Company |^ Printed in U.S.A.
Corrosion/Etching Damage
Line spalling: Roller spaced spalling from bearings operating after etching damage.
Etching: Rusting with pitting and corrosion from moisture.
Staining: Surface stain with no significant corrosion from moisture.
True Brinelling
Damage from shock or impact.
Misalignment Damage
Irregular roller path from deflection, inaccurate machining or wear of bearing seats.
High Spots In Cup Seats
Localized spalling on the bearing cup (outer race) from stress riser created by split housing pinch point.
WARNING Failure to observe the following warnings could create a risk of death or serious injury.
Never spin a bearing with compressed air. The components may be forcefully expelled. Proper maintenance and handling practices are critical. Always follow installation instructions and maintain proper lubrication. A bearing/component should not be put into service if its shelf life has been exceeded.
CAUTION Failure to follow these cautions may result in property damage
Use of improper bearing fits may cause damage to equipment. Do not use damaged bearings.
TechTips is not intended to substitute for the specific recommendations of your equipment suppliers. Every reasonable effort has been made to ensure the accuracy of the information contained in this writing, but no liability is accepted for errors, omissions or for any other reason.
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