Product category:
Gears, brakes, couplings and engines
News Release from: Eriks UK | Subject: Tolerance rings
Edited by the Engineeringtalk Editorial
Team on 10 September 2002
Tolerance rings cut down transmission
systems
Wyko has introduced an innovative new solution for securing transmission shafts and bearings in machine applications where excessive vibration, misalignment and heat may occur.
Wyko has introduced an innovative new solution for securing transmission shafts and bearings in machine applications where excessive vibration, misalignment and heat may occur The new 'tolerance rings' can also be used as a 'failsafe' device for controlling torque parameters in motor and drive gear assemblies, providing engineers with a cheap alternative to bulky slip clutches
Added benefits for designers in the automotive, domestic appliance and electric motor industries include increased service life, reduction in tolerances and a lighter more compact design and simplified assembly procedures.
A tolerance ring is essentially a cylindrical steel shim with a waveform profile.
It can be used for joining almost any cylindrical mating parts and because of its simplicity is often the lowest cost and easiest-to-fit solution.
Used as a simple fastener, tolerance rings can be used in place of more inconsistent or costly fixing methods such as adhesives, splines, keyways, pins and threads.
In this environment they can be used to secure components made from quite dissimilar materials, such as plastics or powder coated metal components.
Tolerance rings also have significant benefits when used in applications where excessive vibration may occur.
The rings are manufactured from spring steel and can be used to fit any design of bearing or shaft interface.
The spring steel provides the necessary force to hold a bearing in place, yet allows for variance in shaft alignment.
The wave profile in the ring itself provides grip while allowing a calculated level of flexibility, preventing the degradation of components and bearing housings experienced on a wide variety of consumer and industrial machines.
In applications such as automotive air pumps and belt sanders, tolerance rings have been used to replace plastic bushings, allowing the units to operate reliably at higher temperatures.
When manufactured in carbon steel, the tolerance rings retain their properties up to 230C, rising to 290C for stainless steel and to upwards of 600C when exotic alloys are used.
The waveform design of the rings also encourages airflow through the machine, allowing bearings to run cooler and avoid overheating of other components.
Additional benefits to using tolerance rings in electric motor designs include the replacement of costly spherical bushings and bearing retaining clips.
Due to the less complex mount and shallower housing depth, motor dimensions can be minimised when specifying rings as an alternative to bushings or clips.
The more compact fitting design reduces machine weight and costs incurred in reaching precise housing tolerances required for traditional methods of mounting.
Installation is also simplified, using a lower press fit force to facilitate faster assembly and disassembly of the final product.
The height, width and pitch of the ring waveforms, in addition to spring stiffness can be modified to create an immovable joint, or allow slippage of mating components within predefined parameters.
Commonly used by car manufacturers on collapsing steering columns and to preventing steering lock systems from being forced, the rings offer solid load bearing capacity up to a prescribed tolerance limit and then give, allowing the shaft to turn.
The rings can also provide an inexpensive, lightweight alternative to slip clutches in motor and drive gear assemblies such as automotive timing belts where they are coated with solid lubricant at the factory. Request a free brochure from Eriks UK ...
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