REXROTH MKD025A-144, Manual

Page: 129 / 184

Synchronous Motors MKD Application Instructions
13-11
DOK-MOTOR*-MKD*******-PR07-EN-P Version7.0 19.05.2004
Output Shaft with Shaft Sealing Ring
MKD motors are designed with radial shaft sealing rings according to
DIN 3760 – design A.
1
RWDR.fh7
(1) Radial shaft sealing ring
Fig. 13-16: MKD radial shaft sealing ring
Radial shaft sealing rings are rubbing seals. Hence, they are subject to
wear and tear and generate frictional heat.
Wear and tear of the rubbing seal can be reduced only if lubrication is
adequate and the sealing point is clean. Here, the lubricant also acts as
coolant, supporting the discharge of the frictional heat from the sealing
point.
⇒
Prevent the sealing point from becoming dry and dirty. Always
ensure adequate cleanliness and lubrication.
The materials used for the radial shaft sealing rings are highly resistant
to oils and chemicals. The performance test for the particular operating
conditions lies, however, with the machine manufacturer’s responsibility.
At the moment of printing of the present document, the following material
assignment is applicable:
Motor Sealing material Short name
MKD Fluorocaoutchouc FPM (Viton)
Fig. 13-17: MKD shaft sealing ring
The complex interactions between sealing ring, shaft and fluid to
be sealed as well as the particular operating conditions (frictional heat,
soiling, etc.) do not allow calculation of the lifetime of the shaft sealing
ring. Under unfavourable terms can be an increase of probability of
failure occured.
The degree of protection on the flange side of motors with shaft sealing
ring is IP 65. Hence, tightness is ensured only in case of splashing fluids.
Fluid levels present on side A require a higher degree of protection. If
the motor is installed in vertical position (shaft pointing up), the
instructions in the section “Design and Installation Positions” in this
chapter must, in addition, be observed.
Wear and tear
Resistance
Vertical installation positions
IM V3