FLENDER Standard Couplings Torsionally Rigid Gear Couplings — ZAPEX ZN Series © Siemens AG 2015 General information ■ Overview Coupling suitable for use in potentially explosive atmospheres. Complies with the current ATEX Directive for: II 2 GD c 120 °C (T4) -20 °C ≤ T a ≤ +80 °C I M2 Materials • Hubs and flanged sleeves: Steel • O ring: Perbunan • Lubricant: Grease filling 5 ■ Benefits ZAPEX gear couplings link machine shafts and compensate for shaft misalignment with weak restorative forces. High transmissible torque combined with compactness and light weight are characteristic of ZAPEX couplings.
ZAPEX coupling types are constructed on a modular principle, so application-related solutions can be delivered quickly. This coupling requires very little maintenance. Regular grease changes at the prescribed intervals prolong the service life of the coupling. ■ Application ZAPEX couplings are especially suited for operation in harsh op- erating conditions, such as drives in the iron smelting or cement industry. ZAPEX couplings are suitable for reverse operation and horizontal mounting positions and, in the case of type ZNNV, for vertical mounting positions. ■ Design A ZAPEX coupling comprises two hub sections with external teeth which are mounted on the machine shafts.
The external teeth engage with a flanged sleeve with corresponding internal teeth. The flanged sleeves are connected via two flanges with close-fitting bolts. ZAPEX ZN gear coupling types ZNN Standard type ZNZS With adapter ZNW With intermediate shaft ZNBG With straight brake disk ZNNA With axial backlash limiter ZNZA With adapter and axial backlash limiter ZNNV Vertical type ZNN For axial displacement The teeth are lubricated with grease. On the ZAPEX type ZN, O-rings are used to seal the tooth space. The O-rings prevent the lubricant from escaping and dirt from entering the tooth space. The parallel keyways must be sealed during assembly to prevent lubricant from escaping.
Customized hub designs are described after the types. Further application-related coupling types are available. Dimension sheets for and information on these are available on request. ■ Function The torque is transmitted through the coupling teeth. The teeth are crowned, so angular displacement per tooth plane is possi- ble. Radial misalignment can be compensated for via the space VA between the tooth planes. The internal teeth of the flanged sleeves are significantly wider than the external teeth of the hub parts, permitting a relatively high axial misalignment.
A small angular misalignment on the coupling teeth results in an advantageous distribution of the lubricant film in contact with the teeth and a very low wear rate. This favorable condition can be deliberately set by aligning the drive with the machine shafts with a slight radial misalignment. 5/2 Siemens MD 10.1 · 2015 Type Description