FAQ

A properly calibrated torque wrench is necessary for proper installation of all keyless locking devices, both internal and external.

By design, internal devices fit inside a hole or counterbore in a hub or body of the device being attached.  When the fasteners are tightened, the internal device expands and generates pressures on the shaft and in the hole or counterbore. External devices, by design, fit over a hub projection, and by tightening the fasteners, the external device generates a pressure on the hub and, subsequently, on the shaft.

Internal locking devices are supplied from the factory pre-lubricated and should require no additional oil.

The shaft and the corresponding bore of the component being clamped should not be lubricated for optimum torque capability.  However, sometimes residual oils on the shaft can facilitate easier assembly of the component.  NEVER use any grease, especially NEVER use grease containing molybdenum disulfide.

Prescribed tolerances vary for each type of locking device, depending on the design.  Please consult your chosen device’s catalog for the proper tolerance.  If you have tolerances that deviate from those we recommend, please contact us.

The surface finish recommended for each type of device is a general industrial surface finish.  For example, a surface finish of RMS 125 is recommended for most locking devices.  Should you choose to make the surface finish RMS 63 instead the device will function properly.  Surface finishes that are too smooth or too rough will affect the holding capacity of the devices and should be avoided.

Many of our locking devices are available from stock in stainless steel.  If it is not a stock item, most are available upon request in stainless steels and other materials.  Please contact us if you wish to discuss alternative materials.

The maximum angular misalignment capacity of the four (4) bolt disk pack is 1 degree and the six (6) bolt is 0.75 degrees.  Note, however, that if maximum misalignment is used, the life of the coupling will be affected.

The maximum radial misalignment for a double flexing couplings is dependent on the distance between disc packs.  Please consult our RING-flex® catalog for exact values.

Generally, all couplings require that the bolts be torqued by the customer after installation.  Each coupling size may have different tightening torques depending on the bolt size.  Please consult our catalog for proper tightening torques. 

We recommend the ANSI B17 standard for all keyed connections.

The DeformPlusR product is designed to be cycled thousands of times without requiring replacement.  However, it is good practice to periodically inspect each element for wear and tear and replace them as necessary.

Friction springs are unique in that although there are ‘standard’ sizes and configurations there are also many different possibilities for the design.  Special solutions are always available for special needs – please contact us!

The RfN 7012 is not a self centering product while the RfN 7013 is.  This means that in precision applications, the 7013 would offer better self centering and more precise concentricity, but require tight shaft/hub tolerances.  However, many applications require looser shaft or hub tolerances for a variety of reasons and the 7012 product can bridge these tolerances more easily.

As the market leader in keyless shaft hub connections and power transmission (PT) solutions, we are uniquely positioned to offer you our engineering expertise for your PT solutions.

Of course, all Ringfeder products can be purchased either directly from Ringfeder companies or authorized dealers.  Please call us for a referral in your area.