SIEMENS
FLENDER Standard Couplings
Torsionally Rigid Gear Couplings — ZAPEX ZW Series
General information
4/2
Siemens MD 10.1 · 2015
4
■
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
■
Benefits
ZAPEX gear couplings link machine shafts and compensate for
shaft misalignment with weak restorative forces. High transmis-
sible torque combined with compactness and light weight are
characteristic of ZAPEX couplings. ZAPEX coupling types are
constructed on a modular principle.
This means that application-specific solutions can be delivered
quickly. ZAPEX couplings require very little maintenance. Regu-
lar grease or oil changes at the prescribed intervals prolongs 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 ZWNV, for
vertical mounting positions.
■
Design
A ZAPEX coupling comprises two hub sections with external
teeth which are mounted on the machine shafts. Each set of ex-
ternal teeth engages in a flanged socket with mating internal
teeth. The flanged sleeves are connected via two flanges with
close-fitting bolts.
The teeth are lubricated with oil or grease. On the ZAPEX type
ZW, DUO sealing rings are used to seal the tooth space. The
DUO sealing 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 ZW gear coupling types
Further application-related coupling types are available. Dimen-
sion sheets for and information on these are available on re-
quest.
■
Function
The torque is transmitted through the coupling teeth. The teeth
are crowned, so angular displacement per tooth plane is possi-
ble. Radial displacement 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 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 mis-
alignment.
Type
Description
ZWN
Standard type
ZZS
with adapter
ZZW
with intermediate shaft
ZWH
with coupling sleeve
ZWBT
with offset brake disk
ZWBG
with straight brake disk
ZWB
with brake drum
ZWTR
for rope drums
ZBR
with shear pins
ZWS
Clutch
ZWNV
Vertical type
ZWSE
Simple clutch-coupling combination
© Siemens AG 2015