Saint-Gobain Bearings
Electric Motors

Electric MotorThe specific benefits offered by the RENCOL® tolerance ring soon mount up to a significant commercial savings, especially when margins available to OEM manufacturers are under intense pressure to produce products at lower and lower prices.  The table below shows how each benefit offered by the RENCOL® tolerance ring manifests itself in real commercial savings to the manufacturer.





RENCOL® Tolerance Ring Products 


Technology Drives All Types of Electric Motors


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 Non-Automotive Motors 

 Automotive Motors


 Competing Solutions 



Electric Motor Stator MountNon-Automotive Motors

These motors run continuously for long periods under load and can generate high levels of heat.  Furthermore, they have to be as light as possible so designers often use light weight alloys and plastics components, even though this can result in differential thermal expansion problems.  RENCOL® tolerance rings offer the ideal solution to thermal expansion problems as they provide a constant retention force over a wide temperature range and do not require a heavy interference fit that can distort the bearing race.


For cost reasons, a plain bearing is often used on the commutator end of the motor.  Unfortunately, this type of bearing can not cope with angular misalignment of the motor shaft so is unsuitable for many applications.  However, if a RENCOL® tolerance ring is used to retain the bearing, the assembly can then cope with misalignment of the motor shaft and provide long bearing life.


Commutator Brushes

Eliminate set screw and risk of cracking or loosening under vibration.  Avoids use of glue and the associated production costs.



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Automotive Powertrain EngineAutomotive Motors 

Throttle Body Motor Mount

RENCOL® tolerance ring to mount a motor without causing damage to the motor while providing stability during its operating environment.



Starter Motor

RENCOL® tolerance ring to mount a gear, the ring provides simple overload protection in the event of a misfire.



Wiper Motor Bearing Mount

RENCOL® tolerance ring used to mount a bearing / bush in the motor system.




RENCOL® tolerance ring used to mount a bearing in the cast housing.  This is an excellent mounting solution and competes against alternative technologies of plastic / rubber boots and glue.



Air Emission Fan Mount

RENCOL® tolerance ring to mount a plastic impellor to a steel shaft.  This provides sufficient torque to drive the impellor at operating temperatures.




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Relaxed machining tolerances of mating componentsReduction or even elimination of secondary ‘finishing’ operations reduces machining costs, production time and opportunity for quality rejects.
Compensation of angular shaft alignment of rotating shaftsIncreases appliance / motor lifetime and reliability therefore reducing risk of warranty failures.
Allows and controls radial movement of ‘floating’ bearings inside electric motor housingsReduces radial stresses being transmitted from the inner to the outer race of the bearing during thermal expansion of the shaft. This reduction of stresses in the bearing increases the lifetime of the bearing and therefore the motor.
Reduction of radial forces exerted on outer raceof bearingReduction of radial loads on outer race of bearing reduces the stress exerted on the rolling elements of the bearing and therefore increases the bearing lifetime.
Allows for stiffening of assemblyThe ability of the tolerance ring to stiffen any moving assembly allows the design engineer to reduce vibration to a minimum. This reduction in vibration reduces in-service noise levels and also increases product lifetime.
In line torque overload protectionProtect motors from burnout conditions in the event of a blockage. Also protects equipment users from potentially harmful injuries.
Compensation of thermal expansion rates in dissimilar materialsThe use of high expansion housing materials linked to strong drive or bearing materials means that in high-temperature range environments the design engineer risks assembly failure. RENCOL® tolerance rings spring characteristics compensate for this expansion differential and therefore reduces potential assembly failures.

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Competing Solutions 

Electric Motor Bearing Mount
Competing Solution Analysis

 Rubber BootPress FitAdhesiveRENCOL®
Tolerance Ring
Noise / Vibration HDD, Checkmark HDD, Checkmark
Motor Life  HDD, CheckmarkHDD, Checkmark
Operating Temperature HDD, CheckmarkHDD, CheckmarkHDD, Checkmark
Motor EfficiencyHDD, Checkmark HDD, CheckmarkHDD, Checkmark
ReworkabilityHDD, CheckmarkHDD, Checkmark HDD, Checkmark
Temperature Range

HDD, Checkmark


HDD, Checkmark

Mating Component Tolerances   HDD, Checkmark
Perceived Cost  HDD, Checkmark 
Total Solution CostHDD, Checkmark  HDD, Checkmark

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» For more details or information on how we can help you with product solutions in electric motor applications, please visit Sales and Support for regional contact information, or Contact Us directly with your enquiry.



RENCOL® Tolerance Rings

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