Shaft Grounding Rings
Conductive microfiber rings that continuously divert harmful shaft currents to ground — eliminating bearing fluting and electrical discharge machining (EDM) damage in VFD-driven and EV motors. Direct alternative to AEGIS SGR.
Conductive microfiber rings that continuously divert harmful shaft currents to ground — eliminating bearing fluting and electrical discharge machining (EDM) damage in VFD-driven and EV motors. Direct alternative to AEGIS SGR.
AC motors driven by Variable Frequency Drives (VFD) using Pulse Width Modulation (PWM) generate common-mode voltage on the motor shaft through capacitive coupling, causing bearing discharge and EDM pitting, corrosion spots, and groove damage.
Sungturn Shaft Grounding Rings typically use highly conductive materials, such as silver graphite brushes, combined with durable holders made of brass or other metals to guide shaft currents through the end cover to ground, effectively preventing shaft current damage to bearings. Some designs feature split or modular configurations for easy installation and maintenance, and they can be mounted radially or axially depending on motor design. These devices are engineered to handle high RPMs (10,000–20,000) and contaminated environments, often lasting 10 years or more with minimal maintenance.
800V platform protection
Industrial drive protection
Generator shaft grounding
Ship propulsion protection
Precision-engineered conductive grounding rings with microfiber contact technology for reliable shaft current diversion.
Conductive fiber contact ring
Low profile for tight spaces
Mounting holes for easy installation
Secure bracket mounting solution
Conductive microfiber composite with contact resistance <1Ω typical, ensuring effective shaft current diversion.
Inboard or outboard mounting options. Through-hole and bracket mounting designs. Split-ring available for large shafts.
Operating temperature -40°C to +150°C. Suitable for harsh industrial and automotive environments.
Shaft grounding rings safely divert induced shaft currents to ground via low-resistance conductive contact, protecting motor bearings from EDM pitting and fluting caused by VFD common-mode voltage.
Ideal for industrial VFD motors, EV traction motors, Wind Turbines and Marine Motors etc. They prevent over 90% of premature bearing failures and drastically cut costly downtime, with far lower investment compared with motor outage and replacement expenses.
| Shaft Grounding Ring | Ceramic Bearings | Carbon/Copper Brush | Insulated Bearings | |
|---|---|---|---|---|
| Easy Installation | ✔ | ✗ | ✔ | ✗ |
| Maintenance-Free | ✔ | ✔ | ✗ | ✔ |
| Cost-Effective | ✔ | ✗ | ✔ | ✗ |
| Long Service Life | ✔ | ✔ | ✗ | ✔ |
| No Speed Limit | ✔ | ✗ | ✗ | ✔ |
Without SGR
With SGR
| Property | Specification |
|---|---|
| Contact Resistance | < 1 Ω (typical), < 5 Ω (maximum) |
| Current Carrying Capacity | Up to 50 A continuous |
| Operating Temperature | -40°C to +150°C |
| Shaft Surface Speed | Up to 50 m/s (10,000+ RPM typical) |
| Fiber Material | Conductive microfiber composite |
| Housing Material | Aluminum alloy (anodized), Stainless steel optional |
| Mounting Types | Through-hole installation, Bracket installation |
| Protection Rating | IP65 (with proper installation) |
Standard sizes for shaft diameters from 20mm to 110mm. Through-hole and bracket mounting options available.
| Product No. 产品编号 |
Shaft Dia. 轴径 (mm) |
Hole Dia. 孔径 (mm) |
Thickness 厚度 (mm) |
No. of Fiber Clusters 导电纤维簇数 |
Through-Hole Suffix 贯孔后缀 |
Bracket Suffix 支架后缀 |
|---|---|---|---|---|---|---|
| ST-GR-2046-00 | 20 | 46 | 7.5 | 4 | -01 | -03 |
| ST-GR-2551-00 | 25 | 51 | 7.5 | 4 | -01 | -03 |
| ST-GR-2652-00 | 26 | 52 | 7.5 | 4 | -01 | -03 |
| ST-GR-2854-00 | 28 | 54 | 7.5 | 4 | -01 | -03 |
| ST-GR-3056-00 | 30 | 56 | 7.5 | 4 | -01 | -03 |
| ST-GR-3258-00 | 32 | 58 | 7.5 | 4 | -01 | -03 |
| ST-GR-3359-00 | 33 | 59 | 7.5 | 4 | -01 | -03 |
| ST-GR-3561-00 | 35 | 61 | 7.5 | 4 | -01 | -03 |
| ST-GR-3662-00 | 36 | 62 | 7.5 | 4 | -01 | -03 |
| ST-GR-3864-00 | 38 | 64 | 7.5 | 4 | -01 | -03 |
| ST-GR-4066-00 | 40 | 66 | 7.5 | 4 | -01 | -03 |
| ST-GR-4268-00 | 42 | 68 | 7.5 | 4 | -01 | -03 |
| ST-GR-4571-00 | 45 | 71 | 7.5 | 4 | -01 | -03 |
| ST-GR-4874-00 | 48 | 74 | 7.5 | 4 | -01 | -03 |
| ST-GR-5076-00 | 50 | 76 | 7.5 | 4 | -01 | -03 |
| ST-GR-5576-00 | 55 | 76 | 7.5 | 4 | -01 | -03 |
| ST-GR-6086-00 | 60 | 86 | 7.5 | 4 | -01 | -03 |
| ST-GR-6591-00 | 65 | 91 | 7.5 | 4 | -01 | -03 |
| ST-GR-7096-00 | 70 | 96 | 7.5 | 4 | -01 | -03 |
| ST-GR-75101-00 | 75 | 101 | 7.5 | 4 | -01 | -03 |
| ST-GR-80106-00 | 80 | 106 | 7.5 | 4 | -01 | -03 |
| ST-GR-85111-00 | 85 | 111 | 7.5 | 4 | -01 | -03 |
| ST-GR-90116-00 | 90 | 116 | 7.5 | 4 | -01 | -03 |
| ST-GR-95121-00 | 95 | 121 | 7.5 | 4 | -01 | -03 |
| ST-GR-100126-00 | 100 | 126 | 7.5 | 4 | -01 | -03 |
| ST-GR-110136-00 | 110 | 136 | 7.5 | 4 | -01 | -03 |
* Custom sizes available for shafts 115mm and above. Please contact us with your specifications.
* 更多规格及非标尺寸可定制，请联系我们获取完整选型表。
We manufacture shaft grounding rings for virtually any shaft diameter from 6mm to 500mm+. Provide your motor specifications and we'll recommend the optimal solution.
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