Product category:
Springs, dampers, latches, locks and small components
News Release from: Rencol Tolerance Rings | Subject: Tolerance rings
Edited by the Engineeringtalk Editorial
Team on 19 August 2005
Tolerance rings enable stop-start
systems
Stop-start systems for cars and trucks may reduce exhaust emissions and boost fuel efficiency, but they place additional stress on starter motors.
In response to recent research studies, noting that motor vehicles are at a standstill for one-third of the time while travelling in urban areas, stop-start systems are being developed to reduce exhaust emissions and boost fuel efficiency Such systems place additional stress on car and truck starter motors which already have to deliver high levels of torque for cranking vehicle engines in all conditions
This article was originally published on Engineeringtalk on 18 Aug 2008 at 8.00am (UK)
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In cold weather, battery drain and oil viscosity take their toll.
In hot weather, starter heat soak can cause the starter motors to lock up.
Use of tolerance rings as an integral element of motor design provides a simple means of extending life in such circumstances.
According to Peter Safier of Rencol Tolerance Rings: "Stop-start systems operate by cutting the engine when the driver comes to a complete standstill".
"The engine is switched back on when the driver re-applies the accelerator".
"We will no doubt see an increasing number of these systems in the future, leading to a greater demand for overload protection on starter motors".
Rencol has world leading expertise in designing tolerance rings to allow slip to occur between components at a predetermined torque level over multiple slip cycles.
The company has developed a ring for an epicyclic gear reduction starter motor.
During an overload situation - for example, engine rocking or where the torque requirement of the engine for cranking exceeds the motor's capabilities - the ability of the gear to slip will relieve the impact or overload on the motor.
This is in contrast to many current systems which can cause gear damage resulting in reduced motor life.
The Rencol tolerance ring is fitted onto the gear and assembled into the housing.
This provides a simple inline overload protection system designed to slip at torques in excess of 200Nm.
The method allows the design engineer to use lighter and smaller components and replace bulky and expensive clutch mechanisms. Request a free brochure from Rencol Tolerance Rings ...
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