Bibby Transmissions Group




This section shows outline technical details of the most common high performance configurations and sizes, all of which can comply with API671. Alternative arrangements and options are available, many of which are shown on page 14. For further details please contact Bibby Turboflex. Note: Our unique design flexibility means that it is perfectly acceptable for a Bibby Turboflex high performance disc coupling to be different at each end in terms of size and/or style. If the units shown do not appear to meet any part of your requirements please contact our design engineers who will use their vast experience to supply a solution. HS High Performance Couplings The operating principle of disc couplings means that they can be designed using any even number of bolts (4 or above). Half these bolts fit to the "Driving" side and half to the "Driven" side. Hence, in a coupling with a total of 6 bolts (6HS), drive is through 3 bolts. This means that, for a given diameter of coupling, more torque can be transmitted through the 8- bolt (8HS) unit than the 6-bolt (6HS) coupling. However, as the number of bolts increases on a given diameter, the ‘span’ between them decreases and, hence, so does the flexibility of the discs. This brochure outlines couplings with 6, 8 & 10-bolt arrangements. The 6-bolt units have the higher flexibility and the 10-bolt units the higher torque capacity. The 8- bolt (8HS) units offer a compromise of flexibility against torque capacity and are often a good starting point if misalignment expectations are unknown. See page 18 regarding misalignment capacity and select the best to suit your requirement. Bibby Turboflex operate a "Parametric Design Philosophy". The sizes stated here are for standard units. If the design does not exactly fit your application we are able to optimise the coupling without any variation from the well-established and proven design principles. This brochure does not demonstrate the full scope of our experience. Larger or smaller sized units are available upon request. For general purpose disc couplings see page 3. Bibby Turboflex’s design preference has always been for transmission of torque through the disc assembly joint in friction.
	This eliminates the potential for fretting during normal operation and prolongs the life of the coupling. The use of the rating tested in this leaflet, together with the standard API Service Factor will maintain this design principal for steady torque applications. If the torque is not steady, an increased application factor must be considered. Specific Notes The following points should be noted in relation to these products: • Peak torque capacity as defined by API671 (Ed’n 3) is 1.35x stated rating. • Momentary (SCT) torque capacity as defined by API671 (Ed’n3) is 1.9x stated rating. • Misalignment data is shown on page 18 . • Maximum bores are stated for hydraulic fit with the standard 1.5 Boss:Bore ratio. Larger bores may be possible in other cases. • A minimum service factor of 1.5 (in accordance with API671 Ed’n 3) is recommended. See page 15 for further information.	• Maximum speeds are shown for units in standard material & to standard dimensions. Increased speeds may be possible. Materials Standard design uses alloy steel for the major components and bolts but alternative materials are always available for higher stress operation, reduced mass and adverse environments. These include titanium alloy, aluminium alloy, stainless steel, Duplex or Super-Duplex steels and any other material to meet customer's requirements. The flexible discs are normally manufactured in stainless steel but alternative options (including Iconel & Monel) are available to suit specific environments.