HRC couplings connect power transmission shafts together end to end or are used to connect flywheels to shafts. Other than accessory locking plates and bolts, their main components are the two flanges that connect to each shaft end (usually using separate bushes) and the buffering insert that goes between them. This section consists of one optional type of insert to achieve that buffering.

These HRC coupling chloroprene rubber fire resistant inserts are suitable for use within a temperature range of -15 to +70 degrees Centigrade. They have fire resistance and anti-static properties (F.R.A.S) so are approved for use in environments where risks from fire or from static are significant.

Chloroprene is a synthetic form of rubber. Like natural rubber inserts, they have excellent shock-absorbing properties, reduce vibrations, absorb torsional oscillations and misalignments in the coupling and are durable, hard-wearing and chemically resistant. By absorbing shock, vibration and misalignment, all the attached components of your drive transmission system are protected from damage and wear. Using top-quality inserts is a very cost-effective way of extending the lifetime of the system and minimising long-term maintenance overheads and production downtime.

When you unpack your product, you may notice a green smudge or "flash" visible in the rubber. This is not a manufacturing flaw - it is there as an indicator that the insert is F.R.A.S. chloroprene rather than standard natural rubber.

HRC coupling chloroprene rubber fire resistant inserts can be used in combination with a variety of flange variations. Couplings of this type consist of two halves (flanges usually made of cast iron or steel) designed with interlocking "teeth" or other corresponding geometry, with the cushioning rubber insert also designed to fit perfectly between. HRC coupling chloroprene rubber fire resistant inserts are sometimes called "spider" or "star" inserts because of the arms that mate with the cogs of the coupling flanges.

Each flange is attached securely to a shaft end, usually by means of a taper lock bushing (screw threading and welding are other possibilities but rarely to be preferred). The tapering for bush attachment can either be machined inward facing or outward facing and should be chosen in terms of which direction affords the easiest access for fitting. One of the great advantages of bush fitting is that couplings ought to be replaceable without disassembly of the surrounding drive transmission machinery.

Therefore flanges generally come in three "flavours": hub mount ("H type"), which will be assembled from inside the coupling; face mount ("F type"), assembled from the outside; or pilot bored ("B type"), which are intended for on-site adaptation with the machining of your choice. This inserts in this range are equally compatible with all three flange types.

Our HRC coupling chloroprene rubber fire resistant inserts usually come from Dunlop, whose expertise in rubber technologies is unrivalled. Additional advice on choosing your coupling components is available in related sections of our catalogue or from our customer service team.