JOINSHIM® Rings

JOINSHIM® rings are corrugated metal strips that act as radial fasteners offering a low, cost-effective retention solution for joining mating cylindrical parts.  These frictional fasteners assemble quickly and provide retention to securely mount bearings and other components while compensating for small amounts of misalignment and thermal expansion, additionally allowing relaxation of machining tolerances.

This range has been designed to offer mounting solutions for industry standard bearings.

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Types   Benefits   Applications   Why Use to Mount a Bearing?

Installation   Specifications   Test Data

Ring Types

HV type is used for holding a bearing in a housing where no axial movement is required and high radial loads are likely
HVL type is used for holding a bearing in a housing where radial loads are likely
HVUL type is used for holding a bearing in a housing where radial loads are likely and where axial movement is required

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Benefits

• Compensates for thermal expansion of dissimilar components
• Allows the relaxation of tolerances
• Replaces an adhesive or press fit arrangement
• Allows the use of cast or moulded components by relaxing housing tolerances from H6 to H11
• Allows for an angular misalignment, eliminating the need for special housing tooling and added housing length needed for spherical bearings
• Allows axial movement
• Consistency over time, performance doesn't degrade
• Improves noise and vibration
• Reduces heat transfer from outer components and allows the bearing to run cooler, increasing bearing life

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Applications (Floor Cleaners, Transmission Module, Electric Motor Examples)

There are numerous applications and uses for JOINSHIM® rings such as appliances and electric motors.

Floor Cleaners

Floor cleaning products are operated for long periods under a continual load and generate levels of heat that place significant demands on the design.

Designers always look to reduce weight materials such as plastics and zinc or magnesium alloys, as well, the thermal properties of these materials are quite different to steel and often result in different thermal expansion problems.  JOINSHIM® rings offer the following benefits:

• Ideal for fixing plastic components, as they compensate for differential thermal expansion and the 'creep' of material over time
• Simple press fit assembly method with low tooling costs
• Increased life of tooling by compensating for relaxing tolerances
• Ideal for fixing soft materials and sintered materials, as assembly only requires a light press force
• Allows use of components with wide tolerances
• Avoids secondary machining operations and can be used as 'cast' or as 'moulded' components
• Allows disassembly and rework of assembly

Bearing Mounting in  Transmission Module

In this example, JOINSHIM® rings are used to mount transmission component bearings in a plastic housing.  The JOINSHIM® ring allows for misalignment in the moulding process and thermal expansion of the housing, enabling the gears to mesh correctly and provide high levels of reliability.

Electric Motors

• JOINSHIM® ring securely retains bearings under all operating conditions without the need for tight machining tolerances or glue
• Provides a consistent retention force between mating components with different thermal properties over a wide temperature range
• Can be used to change the stiffness of the bearing assembly so that noise and vibrations are reduced
• Minimises 'torque ripple' and functional losses in the bearing
• Increases tool life by compensating for changing / relaxing tolerances
• Allows use of an 'as moulded' or 'as cast' housing 

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Why use a JOINSHIM® Ring to Mount a Bearing?

The JOINSHIM® ring compensates for thermal expansion of dissimilar components and allows the relaxation of tolerances.  It also replaces an adhesive or press fit arrangement. 

The use of a JOINSHIM® ring allows the use of cast or moulded components by relaxing housing tolerances from H6 to H11.  Allowing for an angular misalignment eliminates the need for special housing tooling and added housing length needed for spherical bearings.

JOINSHIM® ring also affords axial movement.   Performance over time means that performance doesn't degrade.  Noise and vibration are improved, and heat transfer from outer components is reduced, allowing the bearing to run cooler, increasing bearing life.

	By altering the spring constant "K" of the tolerance ring, it is possible to tune the resonance frequency of the assembly.
	Maximum amplitude of vibration at resonance frequency means that design engineers must ensure that resonance does not occur at working frequencies.
	Resonance frequency has been altered by changing the stiffness of the joint using a JOINSHIM® ring with a higher spring constant "K."

 Lower noise and vibration readings are shown by the greater blue and black areas on the JOINSHIM® graphs.  These greatly reduced noise levels (10dB) result in a motor that is half as noisy as a press-fit bearing motor.  This is especially useful in appliances and tools to keep noise and vibration levels reduced.

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Installation

Step 1:  Ensure bearing and ring size correspond.
Step 2:  Confirm the housing bore size corresponds with JOINSHIM® ring specifications.  If not, machine the housing to the recommended diameter from the data tables.   Note:  The bearing bore should allow for a minimum 2mm wall thickness remaining after machining steel housing at least 3mm for an aluminum, zinc or magnesium housing, and 4mm for a BMC / plastic housing.
Step 3:  Insert the ring by carefully squeezing the free ends together and placing into a bore.  Care should be taken to ensure the ring nests squarely in the housing bore.  If there is no shoulder in the housing bore, it will be necessary to use a backing plate behind the ring to prevent it from sliding out of position when the bearing is inserted.
Step 4:  Place the housing and ring assembly along with the bearing into an assembly press fixture.  A fixture is necessary to ensure that the bearing and bore are held concentric and square to one another.
Step 5:  Apply a uniform and consistent force using an arbour press or hydraulic cylinder to fully seat the bearing in the bore.

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Specifications 

Each ring will have a unique part number.  The description of the ring can be found under the part number.  Part descriptions are written as follows:

HV or SV (Prefix), Ring Diameter, followed by Ring Width and Material Type.  Example:  HV 22 x 7 SS=Ring  (Type HV, Diameter 22mm, Ring Width 7mm, Material Stainless Steel)

Part numbers and descriptions can be found by selecting the product data tables.

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Test Data 

We strongly recommend a performance-testing program in order to establish actual assembly performance.  It therefore follows that it may be necessary to revise the housing diameters based on actual test results.

Performance validation must be conducted with production intent components.  Final design validation is the customer's responsibility.

Compression Curve

Additional test data information is available from the JOINSHIM® Ring brochure.

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»  For more details on this product, please visit Sales and Support for regional contact information, or Email Us directly with your enquiry.