Siemens SIMOTICS M-1PH8, Operating Instructions Manual

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Mechanical mounting
4.7 Mounting of rotating unions on 1PH8 hollow-shaft motors
1PH808/1PH810 main motors
Operating Instructions, 04/2017, 610.48004.40f
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4.7 Mounting of rotating unions on 1PH8 hollow-shaft motors
General information
1PH8 main motors with a hollow shaft (13th position in the Article No.: " 3 ") are designed
as main spindle motors for machine tools and machining centers with internal tool cooling.
A rotating union is required for the provision of the coolant in the rotating motor shaft.
A rotor-supported or, for a motor ordered with option Y64, a bearingless, frame-supported
rotating union can be mounted on the NDE shaft extension. In addition to coolant, suitable
rotating unions can also transfer oil mist (minimum quantity lubrication), cutting oils or even
compressed air at standstill.
Rotor-supported rotating unions consist of the following components:
● Rotor with bearing
● Stator
● Enclosure with cable connections
● Floating-ring shaft seal
Rotor-supported rotating unions are easy to fit and change. They are screwed into the motor
shaft via the thread on the rotor. The advantage of these rotating unions is the leading off of
the leakage via the housing and the integrated leakage connection.
Bearingless, frame-supported rotating unions are made up of two separate parts, the rotating
part with a mechanical seal and the static part with a mechanical seal and supply
connection. By eliminating the bearings, higher speeds can be achieved and the rotating
union is less sensitive to vibrations and lateral loads. However, an adapter such as is
described in Ch. "Suggestion for an adapter for bearingless, frame-supported rotating
unions" for installing the rotating union is required.
Installation must be performed very carefully because the sealing surfaces of the mechanical
seal are not protected.
The rotating part is bolted into the NDE end of the motor shaft. The static part is mounted on
the encoder cover of the motor via an adapter. The adapter must include a facility for
draining leakage. The adapter must be designed in such a way that the motor is not flooded
by the leakage and the degree of protection of the motor is complied with. It may be
necessary to use sealing air.
For use of a bearingless rotating union, the motor must be ordered with option Y64 and the
interface on the encoder cover must be located concentrically with respect to the shaft. The
mounting conditions stated by the manufacturer of the rotating union must be met.
Depending on the type of rotating unions, the sealing rings may be permanently or
temporarily in contact.
Example of a closed seal: DEUBLIN series 1116 and 1108
Example of an opening seal: DEUBLIN series 902 and 1109