SIEMENS
FLENDER Standard Couplings
Torsionally Rigid Gear Couplings — ZAPEX ZN Series
General information
5/2
Siemens MD 10.1 · 2015
5
■
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
■
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.
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.
ZAPEX ZN gear coupling 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.
Type
Description
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
© Siemens AG 2015