Slip Rings for Bearing Protection
For many years, Mercotac® Brushless Slip Rings have been the top choice for a diverse range of industries and applications, including for Bearing Protection, due to their various advantages, such as
- Diverting motor shaft voltage to protect bearings from damage
- Continuous 360 degree rotatio
- Long life without any maintenance
- Low resistance
With the advent of motors controlled by VFD’s (variable frequency drives) a new problem surfaced which damages the ball bearings. This type of damage can also happen from asymmetry in the motor’s magnetic circuit and unshielded power cables. VFD’s different electrical waveform causes an electrical voltage to build up on the motor shaft. When the voltage is high enough to overcome the insulation of the bearing grease the voltage will arc or cause an electrical discharge through the bearing balls. This discharge causes micro pitting. Even a few volts can cause this damage. Over time, the pits increase and become deeper and the bearings prematurely fail. For larger motors, like the ones used in commercial HVAC systems this can be an expensive proposition.
One costly way to fix this problem is to use ceramic ball bearings as they do not conduct electricity. An alternate more economical way to alleviate the bearing arcing is to provide a ground for the motor shaft which bleeds off any induced voltages.
Grounding the shaft of a Variable Frequency Drive controlled motor will eliminate the damage to the bearing balls by electrical discharge. By using a Mercotac brushless slip ring to electrically ground the shaft, there exists no possibility of discharge through the bearings.
What can we help you with next?
How to Order Mercotac® Products: Order directly from Mercotac from within the USA, or through an authorized distributor if outside of the USA.Learn More
Frequently Asked Questions: Learn about the benefits of Mercotac products. We strive to answer all of your brushless slip ring questions. Learn More
Check out our Mercotac® Learning Center: Here we offer guidance for engineering designs that utilize our brushless slip rings. Learn More