Siemens 1LA8, Operating Instructions Manual

Page: 26 / 174

Cooling
The cooling system is designed as a closed, internal cooling circuit. The heat lost from the
machine is dissipated to the ambient air via the machine's surface. A shaft-mounted fan moves
the cooling air in the primary circuit. Movement of the cooling air in the secondary circuit is
driven by a shaft-mounted fan.
Fan
● The internal fans are bidirectional.
● External fan:
– Machines with four poles and more as well as 1L.831.‑2: The external fans are
bidirectional.
– Two-pole machines except 1L.831.‑2: The external fans are unidirectional. The
machines have an additional label on the end shield and on the rating plate with an
arrow indicating the direction of rotation.
The 1L.831.‑2 can optionally also be equipped with a unidirectional external fan.
Rolling-contact bearings
The machines are equipped with different types of rolling-contact bearings depending on the
version and the operating conditions described in the order. The different types are listed on
the lubricant plate of the machine. In converter operation an insulated bearing is usually
installed on the non-drive end. The following rolling-contact bearing variants are available:
Table 3-4 Rolling-contact bearing variants
Version Rolling-contact bearing
Horizontal type of construction,
coupling output
● Drive end: Deep-groove ball bearing as a fixed bearing
● Non-drive end: Deep-groove ball bearing as a floating bearing
with axial compression springs
Horizontal type of construction,
for increased transverse forces
e.g. in the case of belt coupling
● Drive end: Cylindrical-roller bearing as a floating bearing
● Non-drive end: Deep-groove ball bearing as a fixed bearing
Vertical type of construction,
shaft height 315, coupling output
● Drive end: Deep-groove ball bearing as a fixed bearing
● Non-drive end: Deep-groove ball bearing as a floating bearing
with axial compression springs
Vertical type of construction,
shaft height 355 ... 450
● Drive end: Pairing of angular-contact ball bearing / deep-groove
ball bearing as a fixed bearing
● Non-drive end: Deep-groove ball bearing as a floating bearing
with axial compression springs
Description
SIMOTICS TN Series N-compact 1LA8
26
Operating Instructions 05/2014