Rolling bearing manufacturer NKE Austria (www.nke.at/en) has unveiled its latest range of electrically insulated rolling bearings. Featuring a built-in electrical insulation, the special bearings SQ77 offers reliable protection from current discharge as well as the resulting electrical corrosion. The electrically insulated rolling bearings are ideally suited for various applications such as generators, electric motors and other electric machines.

The company’s all-new electrically insulated bearings come in three different variants — the SQ77, the SQ77E and the SQ77B series.

The outer ring of the SQ77 series is designed with an oxide ceramic, while the inner ring of the SQ77E features an insulation layer. The SQ77B’s hybrid bearings are integrated with ceramic rolling elements and theoretically infinite insulation resistance.

In addition, the ceramic insulation of the SQ77E and SQ77 series is applied via plasma-spraying. It also features a minimum guaranteed dielectric strength of 1000 V DC or AC.

Meanwhile, the bearings with outer ring insulation are offered as deep groove ball bearings and cylindrical roller bearings in various dimension series, radial clearance classes and designs.

Unlike conventional bearings available in the market, the electrically insulated bearings from NKE are more reliable in operation particularly in electrical machinery. This is primarily attributed to the bearings increased protection from electrical corrosion. Aside from being reliable, the bearings are also more cost-effective than a housing or shaft insulation.

The electrically insulated rolling bearings feature similar technical properties and key dimensions as conventional bearings. Thus, they can be interchanged.