Seal prevents shaft current damage to bearings
- Publisher
- Elsevier Science
- Year
- 2006
- Tongue
- English
- Weight
- 51 KB
- Volume
- 2006
- Category
- Article
- ISSN
- 1350-4789
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✦ Synopsis
Inpro/Seal has announced its Motor Grounding Seal (MGS), an innovation based on the bearing isolator for which the company is known. The grounding seal is designed to stop the damaging effects of residual shaft currents in AC motors.
Specifically developed for variable-frequency drive (VFD) controlled AC motor applications, the seal prevents pitting, fluting and fusion craters while protecting the bearings from contamination.
VFD systems inherently generate residual current or shaft voltage that accumulates on the rotor and discharges through the motor bearing. This random and frequent discharging is referred to as the electric discharge machining (EDM) effect, a phenomenon that causes pitting on the bearing's rolling elements and raceways.
The new seal includes a grounding ring and brush built into the bearing isolator. The grounding ring dissipates the current and gives it a path