Volsun Shaft Grounding Ring-An Innovative Protection Solution For Motors’ Bearings

Why does the drive motor system need to use a shaft grounding ring?

With the rapid development of the new energy vehicle industry, the drive system faces unprecedented harsh working conditions: the operating voltage is as high as 800V, the switching frequency is as high as 20kHz, and the speed climbs to 20, 000rpm. Industry measured data show that under typical working conditions, the contact surface voltage of the motor bearing can reach 20-100V, and the discharge current density exceeds 0. 1A/mm². We know that when the bearing voltage is greater than the threshold voltage of the bearing oil film, the oil film will be broken down and discharged, causing various electrical corrosion damages to the bearing, such as pitting, spark marks, grease aging and deterioration, washboard grooves, white tissue peeling, etc. , resulting in the bearing life of some models being shortened to one-third of that of traditional models.

In order to solve the problem of electrical corrosion of motor bearings, various anti-electrocorrosion technologies are becoming more and more mature. Various measures can be reasonably matched according to the risk level of shaft electrical corrosion. The current industry solutions mainly have three technical approaches:.

1. Conductive technology: bypass the shaft current through a low-impedance path (such as shaft groudning rings, carbon brushes).

2. Blocking technology: use insulating bearings or ceramic coatings to block the current path.

3. Reduction technology: reduce interference sources through PWM optimization or common mode filtering.

The shaft grounding ring produced by Volsun solves the problem of motor shaft electrical corrosion by bypass grounding. It is composed of conductive fibers, metal bodies, etc. , and is used for electrical corrosion protection of variable frequency motors and their coupling equipment. The Volsun conductive ring can reduce the induced potential between the bearing and the grounded housing, effectively reduce the hazards such as electrical corrosion caused by shaft current, and protect the motor bearings to ensure the long-term and stable operation of the motor.

Volsun has developed and produced a variety of series of shaft grounding rings according to market demand. The most common shaft grounding ring is round, and there are also circular welding type, fan-shaped, T-shaped, rectangular, etc.

Volsun has passed ISO 9001 and IATF 16949 dual quality system certifications. It has a team dedicated to the research and development and production of shaft grounding rings, a Class 10 clean workshop and a full set of professional testing equipment. Compared with similar foreign products, the price is about 50% lower, making it more competitive.

Facing the challenges of motor drive system reliability, Volsun will continue to deepen its roots in the field of shaft current protection and provide customized solutions for new energy vehicle motors, engineering vehicle motors, rail transit hub motors, etc. Welcome to contact us for more details!