SKF, global bearings and engineering solutions specialist, supplies a sensor bearing with an in-line electromagnetic compatibility (EMC) filter that offers improved protection of sensitive sensor bearing electronics from high electric stresses.
When the nominal lifetime of a machine element like a bearing is compared with the nominal lifetime of electronics like a sensor, the electronic component will most of the time exceed the mechanical by far. But in an industrial environment, the electronic component faces electric overloading like power surges and electric discharges which can reduce the lifetime of the component.
In stringent applications such as for example fork-lifts operating in sugar factories or on insulated floors, a very strong electrostatic charge build-up can occur on the fork-lift frame. If the fork-lift moves close to steel objects like racking, an abrupt discharge can occur; the resulting discharge spark can have a damaging effect on electronics. While it may not have a direct impact on sensors or the control unit, the change in voltage can have a ‘rebound’ effect creating voltage surges in the lines. These voltage surges, which can result in Electrical Fast Transients (EFTs) ranging from 100V to 4,000V, can have a temporary impact on the electricity supply, or even damage the controller or sensors completely.
Following an in-depth analysis of this phenomenon as it relates to sensor bearings, SKF developed the in-line EMC filter to protect the Hall sensor and other electronics used in its bearings. The EMC filter, when applied in-line with the cable, improves sensor bearing reliability, reduces downtime and decreases maintenance costs.