Technical data

MHD Sychronous motors Notes Application 16-15
DOK-MOTOR*-MHD********-PR05-EN-P
Output Shaft With Shaft Sealing Ring
MHD motors are designed with radial shaft sealing rings according to DIN
3760 – design A.
1
RWDR.fh10
(1) Radial shaft sealing ring
Fig. 16-20: MHD radial shaft sealing ring
Radial shaft sealing rings are rubbing seals. Hence, they are subject to
wear and generate frictional heat.
Wear of the rubbing seal can be reduced only if lubrication is adequate
and the sealing point is clean. Here, the lubricant also acts as a 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.
Note: Under normal environmental conditions the shaft seal is
greased for lifetime. Under unfavourable environmental
conditions (e.g. grinding dust, scops) maintantace could be
necessary.
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, within the machine manufacturer’s responsibility.
As of the publication date of this document, the following material
assignment is applicable:
Motor Sealing material Short name
MHD Fluorocaoutchouc FPM (Viton)
Fig. 16-21: MHD 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.
The degree of protection on the flange side of motors with a 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
Resistance
Vertical installation positions
IM V3