H-C High Performance Couplings | John Crane Power Transmission Couplings


High-performance, Reduced-moment and Low-windage Design (API 671 and ISO 10441)

H-C couplings offer the lowest possible overhung moments and additional shrouding of the flexible elements and bolts. This arrangement produces a high-integrity coupling suited for most medium-speed and high-speed compressor drives.

The factory assembled H-C hub/flex units are designed to accommodate typical machine shaft sizes for turbo compressor applications. The separate spacer on the H-C can be varied to provide the appropriate distance between shaft ends and the required torsional stiffness to suit individual applications. On some applications, the H-C hub assembly on a compressor or gearbox input shaft is combined with the flanged H-F arrangement for a turbine driver.



  • California Residents: PROPOSITION 65 WARNING
  • Fit and forget: The H-C coupling is designed for infinite life and with correct machinery alignment will out last the machines it is connected to.
  • Low imposed loads: The membranes have been designed to optimize their torque capability, while minimizing the reaction forces due to misalignment so reducing machinery vibration and maximizing bearing life. Thus maximizing the life of the machines connected.
  • Zero maintenance: The coupling has no relative moving parts, and hence requires no lubrication or routine maintenance.
  • Axial adjustment shims: When the coupled machines use tapered shafts, high performance couplings are supplied with stainless steel shims for axial adjustment.
  • Anti-fly retention: The spacer is retained by specially designed anti-fly guard rings to ensure safe operation. Additionally the flanges connected to the membranes are interlocked in the event of torsional overload. This reduces the peak stresses on the flexible elements, ensuring continuity of drive under emergency conditions.
  • Balance: component and assembly balance procedures and precision balancing machines assure compliance with ISO 10441 (API 671) or similar specifications. Bolts and nuts are supplied weight-balanced, and on high-speed couplings, trim balancing holes are incorporated.
  • Standards features: All H-C high-performance couplings are supplied with transportation bolts and gag sleeves as standard. These bolts are also used to compress the flexible assembly as an aid to installation.

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