Sub-oil engine
An oil-immersed motor is a three-phase asynchronous machine , which fully in the medium oil immersed is in use. The sub-oil motor is mostly used to drive pumping systems. The housing is open and made of a rigid, torsion-resistant steel construction. To make it easier to mount the pump, the rotor has a hollow shaft with a wedge track on the drive side for torque transmission. It is therefore mounted on the output side of the feed pump, while the opposite end of the rotor shaft is guided through a low-maintenance bronze slide bearing .
advantages
In contrast to air, the high thermal conductivity of the oil enables the three-phase motor to be efficiently cooled by the surrounding oil, which enables a high power density. This type of drive system is therefore used in particular where space is limited. The sub-oil motor is also extremely easy to maintain, as the bearings in the oil bath are subject to little wear. Due to these properties, the submerged motor is used in particular in systems with high availability requirements. The use of material for the magnet system of the motor can be reduced somewhat, the bearings on the shaft side and elastic coupling elements can be dispensed with, which can also save costs.
disadvantage
Since oil has a much higher viscosity than air, the rotation resistance of the rotor in the oil increases compared to that of the air-cooled three-phase motor. The associated loss of efficiency means that the oil-submerged engine is not suitable for continuous operation for economic reasons.
operation area
General oil production, hydraulics (especially complete units in the lower performance range), cooling and lubrication systems
See also
literature
- Rolf Fischer: Electrical machines . 9th edition. Hanser, 1995, ISBN 3-446-18423-6 .
- Hans-Ulrich Giersch, Hans Harthus, Norbert Vogelsang: Electrical machines . 5th edition. Teubner, 2003, ISBN 3-519-46821-2 .