FAQ


  • Is a torque wrench necessary for proper installation?

    Answer:

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

  • What is the functional difference between internal and external locking device?

    Answer:

    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.

  • Is it necessary to lubricate the internal locking device before use?

    Answer:

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

  • Is it necessary to lubricate the shaft for internal and external clamping devices?

    Answer:

    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.

  • What tolerances are necessary for each type of locking device for proper installation?

    Answer:

    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.

  • How critical is surface finish?

    Answer:

    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.

  • Are locking devices available in stainless steel or other materials?

    Answer:

    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 steel and other materials. Please contact us if you wish to discuss alternative materials.

  • What is the maximum angular and axial misalignment capacity for a RING-flex® single flexing coupling?

    Answer:

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

  • What is the maximum radial misalignment capacity for a RING-flex® double flexing coupling?

    Answer:

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

  • What is the recommended tightening torque for the coupling bolts? Are the bolts pre-torqued at the factory?

    Answer:

    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. 

  • What are the tolerance allowances and fits for bore and keyed shaft connections?

    Answer:

    We recommend the ANSI B17 standard for all keyed connections.

  • When do I need to replace a DeformPlus R element?

    Answer:

    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.

  • If the ring-spring in the catalog do not appear to meet my needs, can you design a special solution for me?

    Answer:

    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!

  • When would a RfN 7012 product be preferred over a RfN 7013?

    Answer:

    The RfN 7012 is not a self-centering product while the RfN 7013 is. This means that in precision applications, the RfN 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 RfN 7012 product can bridge these tolerances more easily.

  • Does RINGFEDER POWER TRANSMISSION provide technical support in the form of design assistance or application engineering?

    Answer:

    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.

  • Where can I purchase RINGFEDER products?

    Answer:

    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.

  • What is a RINGFEDER® Friction Spring?

    Answer:

    RINGFEDER® Friction Springs consist of nested inner- and outer rings which have conical surfaces. A general application field is machine engineering, where high kinetic energies have to be absorbed and damped, or whereever springs are required to absorb high forces at relatively low dimensions.

  • What is the functional principle of a RINGFEDER® Friction Spring?

    Answer:

    If a RINGFEDER® Friction Spring is axially loaded, the outer rings are pushed onto the inner rings. During this process the outer rings are expanded, the inner rings are compressed, so the spring column is pusehd together.

  • In what temperature range can a RINGFEDER® Friction Spring be used?

    Answer:

    RINGFEDER® Friction Springs can unconsidered be used in a temperature range from -40°C up to +80°C. In case of temperatures beyond this range it is required to contact RINGFEDER for technical clarification. The max. possible temperature range is -140°C up to +200°C.

  • Is it possible to reduce the damping?

    Answer:

    Yes, the damping can be reduced. To reduce the damping, it is possible to use different types of special lubricants. Each lubricant has its specific friction coefficient. The smaller the friction coefficient is, the lower the friction between the rings and thus the damping gets. That way it is possible to reduce the damping up to 30%.

  • What are typical applications of RINGFEDER® Friction Springs?

    Answer:

    RINGFEDER® Frictions Springs are frequently used in the areas machine engineering and steel construction, also applied e.g. in crane runways, overhead gantry cranes and railway vehicles as buffers. In case of spring suspension, you often find application fields in steel-mills and e.g. stopper devices.

  • What is the material of RINGFEDER® Friction Springs?

    Answer:

    RINGFEDER® Friction Springs are manufactured from REES, a high-tensile spring steel. There a special demands made on the purity grade of this material. It is commercially not available.

  • Do RINGFEDER® Friction Springs operate with any lubricant?

    Answer:

    RINGFEDER® Friction Springs must only be greased with the approved special lubricants of RINGFEDER POWER TRANSMISSION GMBH. In case other than the given lubricants are used, the lifetime of the RINGFEDER® Friction Springs can be significantly negatively influenced.

  • What happens if a ring breaks?

    Answer:

    In case an outer ring breaks, the pretensioning force of the spring is correspondingly reduced. Also the proportionate spring travel and spring work will be reduced. However, there of the function of the remaining rings will not be influenced.

  • Is the function guaranteed even in case of longer non-use?

    Answer:

    One big advantage of RINGFEDER® Friction Springs is, that even after a longer standstill the spring will unchanged have a 100% availability for use. Precondition in this case is, that moisture and dirt is kept away from the spring, because dirt and moisture harm the lubrication.

  • What has to be specificly considered for the use of RINGFEDER® Friction Springs?

    Answer:

    The RINGFEDER® Friction Springs rings have to be coplanar arranged as a spring column and must be protected against environmental influences.

  • Do RINGFEDER® Friction Spring have to be aligned in a guidance?

    Answer:

    RINGFEDER® Friction Springs should either have an outer or inner guidance, at which the outer guidance is to preferred. Exceptions apply for springs with short overall lengths, i.e. if the length does not exceed the 1.5 times diameter and it is ensured, that the spring is loaded between two parallel plates.

  • In what way are RINGFEDER® Friction Springs different to other systems?

    Answer:

    RINGFEDER® Friction Springs differ from other systems through the very compact design. Compared to other springs they are very small, but can absorb a considerably higher force and energy.