Output Shaft With Labyrinth Seal - Bosch Rexroth MAD Project Planning Manual

MAD / MAF Asynchronous Housing Motors
Resistance
Vertical installation positions IM
V3 / IM V6
9.12.4

Output shaft with labyrinth seal

Fig. 9-11: Shaft sealing ring
Wear Radial shaft sealing rings are friction seals. They are therefore subject to
wear and generate frictional heat. Wear symptoms of the rubbing seal can be
reduced if the sealing point is adequately clean. The service life of the sealing
lip at the radial shaft sealing ring depends on the cleanliness and the motor
speed.
The materials used for radial shaft sealing rings are highly resistant against
oils and chemicals. The suitability test for the particular operating conditions
lies, however, within the machine manufacturer responsibility.
The following material assignment has been applicable as of the publishing
date of this document:
Motor MAD/MAF ...
100 ... 225
Tab. 9-18: Material shaft sealing ring
The complex interactions between sealing ring, shaft and fluid to be sealed
on the one hand and the particular conditions of use (frictional heat, soiling,
etc.) on the other hand do not allow any accurate calculation of the service
life of the shaft sealing ring.
However, with a circumferential speed of 5 m/s and under favorable condi‐
tions (e.g. sufficient cleanliness and lubrication), a service life of 5,000 ...
10,000 h can be reached.
Motors with shaft sealing ring have protection class IP65 on the flange side.
The tightness is therefore only guaranteed for splash liquids. Here, it has to
be noted that continuously incoming splash fluids accumulate between motor
shaft and shaft sealing ring due to the adhesive forces at the sealing point, so
that they act as present fluids. Continuously incoming splash fluids require a
higher degree of protection than, e.g., a labyrinth seal.
If the motor is installed in a vertical position, please additionally observe the
guidelines in chapter 9.6.3 "Vertical installation positions" on page
To be protected against incoming splash fluids at the motor output shaft,
MAD/MAF motors can also be directly ordered with a labyrinth seal. Please
also observe the correct order designation of the motors in the motor type
code in this context.
Proper functioning of the labyrinth seal is only ensured when
● the motor is installed horizontally,
● the drain hole is positioned below the output shaft,
● the fluid level present at the motor is at least 5 mm below the drain hole,
● the motor speed is at least 200 min
Sealing material
Polytetrafluoroethylene
-1 .
R911295781_Edition 11 Bosch Rexroth AG
211/265
Application notes
Short description
PTFE
195.