E-Type Bearings
EF-Type
The EF design is especially suitable for electrical machines which do not have their own bearing foundations or the alignment work that goes with them, because they enable significantly shorter bearing clearances and therefore more rigid rotor constructions in comparison to pedestal bearings. The integrated side flange on the housing permits the bearing to be installed directly on the nameplate. The surfaces of the housing are optimally finned for excellent, natural cooling characteristics. The EF type is especially suitable for electric machines which do not have their own bearing foundations or the alignment work that goes with them. However, the nameplates must be torsion-resistant and able to absorb the bearing loads. Significantly shorter bearing clearances, and therefore more rigid rotor constructions in comparison to pedestal bearings. Self-adjusting, floating labyrinth seals are standard fitted to seal the shafts on the concealed side of the machine. We recommend using chamber seals in cases where there is an increased circulation of lubricant, or due to unique specifications. Access through the interior of the machine must be provided for to enable assemble and adjustment of these seals. Thanks to the numerous advantages it offers, the EF type is the most popular design for electrical machines. Side flange-mounted bearings of the type EF are less suitable for machines with sensitive rotor dynamic characteristics and/or rotors with supercritical speeds. In this case, the ER, EG, and EM housing versions offer more advantageous conditions.
EG/ER-Type
Pedestal bearing housings, i.e., housings intended to be positioned on foundation constructions, are widely used in general mechanical engineering applications. Pedestal bearing housings, i.e., housings intended to be positioned on foundation constructions, are widely used in general mechanical engineering applications. The housings up to size 45 are designed with finned surfaces to allow for the best possible dissipation of heat to the surrounding air. Self-cooling bearing designs are still feasible for numerous applications in this size range. Sizes 18 to 45 are available with either a finned or smooth surface, and with smooth surfaces only from size 56 and up. The simpler, smooth design is always sufficient when the lubricant is cooled externally (external lubrication systems). The type ID for smooth pedestal bearing housings is EG, and ER for the finned version. The shaft heights of the pedestal bearings are selected such that the housing can be easily located at the shaft heights of the machines using foot plates or consoles. When the bearing shells and seals are dismantled, the housings can be slid in the axial direction without removing the rotor. If the housings are standing on intermediate pedestals (consoles), they can be lowered and pulled away to the side once the consoles have been removed. The foundations should be constructed with a sufficient level of rigidity to ensure that the machines operate smoothly and reliably.
EM-Type
Slide bearings of the the EM type make it possible to provide very large access areas to the interior of the machine and the bearings for installation purposes – an extraordinary advantage when assembling the machine and performing maintenance work. This housing shape serves as a very suitable basis for a wide range of expansion stages in demanding drive concepts in particular. We developed the EM bearing type to meet the need for extremely small bearing clearances with a simultaneously high level of structural strength of the assembly unit, consisting of the nameplate and bearing. The mounting flange is located in the axial center of the housing and therefore enables the direct, vertical application of loads into the nameplate. The bearing housing is connected via the lower section of the housing. This means that the nameplates can also be split, and only the lower half needs to exhibit a high degree of rigidity. Very large access areas to the interior of the machine and the bearings can be provided for installation purposes – an extraordinary advantage when assembling the machine and performing maintenance work. This housing shape serves as a very suitable basis for a wide range of expansion stages in demanding drive concepts in particular. You could say that the EM type is a functional, multi-purpose bearing – for durable, low-speed machines up to turbo generators running at maximum speeds. The centrally flange-mounted bearings designed with an enlarged housing surface (ZM7, EM9S, EM14S/XS) are a special type of bearings for smaller shaft diameters. In cases where products exhibit a low degree of variation, these bearings offer optimized functionalities for operation with natural cooling, which means that two-pole electrical machines, for example, can be built without separate lubricating units.