KWD Industrial Couplings

Hydrodynamic couplings belong to the group of hydrodynamic power transmission devices. Power transmission is performed by the mass forces of the operating liquid according to the Föttinger principle: the pump impeller absorbs the mechanical power of the drive and increases the energy of the circulating operating liquid, while the turbine wheel takes energy from the operating liquid and outputs mechanical power. There is no fixed connection between the two wheels. Slight power losses caused by the slippage necessary for power transmission are transformed into heat. The permissible ambient temperature range of the standard design is -25 °C to +40 °C (other values on request).

The constant-filling hydrodynamic couplings TK-N can be combined with flexible couplings, brake drums, brake disks and pulleys.

Technical features

• Power transmission free of wear

• Steady, shock-free start-up in loaded or unloaded state

• Low start-up current with fast abatement, relieving the power supply

• Load compensation on multi-motor drives

• Efficient decoupling of vibration systems

• Damping of shocks, vibration and load changes

• Protection against thermal overload by the installed fusible plug or by a mechanical / electronic switch-off device

Types

• A — hydrodynamic coupling with delay chamber

• AV — with enlarged delay chamber

• AVZ — with enlarged delay chamber and additional chamber

• AD — with two hydrodynamic units

• PO / P / PV / PVZ / PD — types AO/A/AV/AVZ/AD with brake drum according to DIN 15431

• SO / S / SV / SVZ / SD — types AO/A/AV/AVZ/AD with brake disk according to DIN 15432

• GMK — with two all-steel coupling halves

• KO / K / KV / KVZ — with pulley

• MEM / MRM — for mounting on the motor shaft; MRM radially removable without moving the drive and driven unit

Main data

• Constant-filling hydrodynamic couplings, nominal sizes 274 – 1,000

• Power range up to 1,750 kW

• Bi-directional rotation; mounting on motor shaft / gearbox shaft — driving on the outer wheel optimises the circuit, improves thermal stability and delivers clear temperature-monitoring signals

• Dynamic balancing to quality Q 6.3 at 1,500 rpm (VDI 2060, two planes)

• Operating liquid: kinematic viscosity 27 – 60 cSt at 40 °C, density 0.85 – 0.91 g/cm³ at 20 °C, flash point ≥ 170 °C, solidification point ≤ -25 °C, water content ≤ 0.1 %, low foaming tendency; water-glycol mixtures possible (with additional bearing encapsulation)

Typical applications

• Accelerating large masses: mills, centrifuges, mixers, blowers, woodworking machines, sieves, ball mills, ropeways and tool machinery

• Start-up against high breakaway torques: mixers, conveyors, crushers, centrifuges and pumps

• Soft start-up and positioning of large mobile equipment

• Safe overload protection: dredgers, crushers, bucket-wheel excavators

• Mobile crushing plants, belt conveyors, long-distance conveyors, scraper conveyors, pipe conveyors

Scope of delivery and optional accessories

• Scope of delivery: flexible claw coupling ELKU-N (nominal sizes 274 – 500) or flexible package coupling (560 – 1,000), standard fusible plug (145 °C) assembled in the coupling, exchangeable standard nozzle set from nominal size 560, fixing elements (hexagon screws, discs and spring washers) supplied loosely

• Optional accessories: insert bushings (for different shaft diameters and lengths), protection covers, replacement fusible plugs (other reaction temperatures), electronic or mechanical thermal switch-off devices, adapted nozzle sets, oil filling, assembly / disassembly tools