Form-Flex® disc style couplings enable high torque transmission whilst simultaneously compensating for angular, parallel and axial shaft misalignment.
A disc coupling is primarily a high performance motion control shaft coupling designed to transmit torque, whilst accommodating for shaft misalignment. Typical applications include Servo Motor connection . The disc coupling designs can handle speeds up to 8500 RPM, using either the single disc set style or double disc set style. Higher rotational speeds can be achieved via balancing and design modifications if required.
Single disc set couplings are composed of two hubs and a single or multi, flat, stainless steel disc set(s) which connect them together via a bolt circle configuration. The double disc design also composes of two hubs, but has an additional centre spacer sandwiching the two disc sets. The centre spacer length dimension can be altered and can also be manufactured from different materials to the hubs to suit various applications. Single disc couplings cannot accommodate large parallel shaft misalignments. Double disc set designs allow a greater parallel offset capability by allowing the two disc sets to bend in opposite directions to absorb the parallel shaft offset. It is also worth mentioning that the hubs are primarily cast, but can be machined and can cater for bore sizes up to 300mm as standard.
The trusted TB Woods Form-Flex metal disc style shaft coupling has successfully been used in conjunction with composite shafting for many years. If an application has a large distance between the driver and driven ends, the traditional design would be to incorporate a steel drive shaft between the two flexible coupling units. However, using steel shafting in this way can have its disadvantages. Primarily, the weight of the connecting shaft could mean additional bearing mounts and inertia problems to the whole design especially when large span distances are required and again when using couplings suited to bore sizes of 25mm and above. (Max 400mm). To overcome this the spacer shaft was supplied using a composite material shaft . The key advantages to using composite shafting lies its weight saving characteristics and the inherent nature to reliably transmit high torques with near zero torsional wind up.
A classic example of the TB Woods Form-Flex capability was recently put to the test at a new pumping house in Malaysia. The original design incorporated 4 very heavy cardan shafts to span a vertical distance of 13.89 metres. During an upgrade of the motors within the plant, to cope with increasing demand, it became apparent that due to poor bearing mounts, large inertia and unbalanced cardan shafting, the plant could not safely operate more than about 5-6 of 9 pumps at a time.
By being able to utilise over 30 years of the technical expertise, the engineers suggested a 3 section lightweight composite Form-Flex coupling design to comfortably transmit the 820Kw at 1500rpm. By reducing the weight of the system it also enabled one of the additional bearing mounts to be omitted, further improving vibration dampening within the design.
Other applications where the Form-Flex couplings and composite shafting combinations have successfully been used include, cooling tower axial fan drives and gearbox to dredge pumps on under water dredging vehicles.
Key product advantages are
- Zero backlash torque transmission
- Compensates for angular and parallel misalignment between shafts
- High-strength, flexible, stainless-steel discs
- To suit shaft sizes from 50mm to 300mm
- Available in three styles: 4-bolt, straight-sided (A, M series); 6-bolt, straight-sided(B Series); 8-bolt, round (D, F, H series)
- Alloy disc sets are also available
- Backlash free and torsionally rigid
- Reduces maintenance time and costs by eliminating lubrication
- Ideal for smooth or uneven conditions and moderate to heavy loads where elastomeric couplings are a typical problem
- Close-coupled, spacer and floating shaft designs offer total solutions for pumps, engine-driven equipment, printing, and positioning systems
ATEX Approved products are available
Servo laminate disc style couplings enable high torque transmission, whilst simultaneously compensating for angular, parallel and axial shaft misalignment. . Another advantage of the product is the way in which the disc packs interlock with alternatively mounted hubs and spacers ensures directional engagement and positive locking.
ATEX key product advantages as as follows
- To suit torques from 5 to 50,000 Nm
- To suit shaft sizes from 10mm to 55mm
- Backlash free
- Torsionally rigid
- Flexible disc couplings minimise the misalignment forces on the connected equipment.
- EC Standard 94/95 versions
- EC (ATEX95) belonging to 2G/2D versions
- Suitable for hazardous environments (up to 280C)
- Laminated disc packs are pre-stressed to eliminate axial vibrations of spacer designs
- Ideal for applications such as centrifugal pumps, fans and screw compressors
If you require further technical information, please do not hesitate to contact our sales engineers who will be more than happy to help you with your selection.