I just want to say a massive thanks to Welink team. We had a really tight deadline for a prototype requiring specific deep groove ball bearings, and they were brilliant. They understood our needs immediately, rushed samples over, and followed up to ensure perfect performance. It's that attentive service that sets them apart. They've been a great help, and we're already looking forward to our next project together. Highly recommended.
Choosing the right deep groove ball bearing for a fan motor directly affects operational stability, noise level, and service life. Below is a selection guide covering key factors and step-by-step procedures.
➊ Operating features of Fan Motors
Before selecting a bearing, it's important to understand the operating conditions of fan motors:
| Features | Description |
| High speed | Fans typically run at medium to high speeds |
| Light load | Primarily radial load, with minimal axial load |
| Strict noise requirements | Household/office fans are sensitive to noise |
| Continuous operation | Most fans need to run for long periods |
| Diverse environments | May face dust, moisture, or high-temperature conditions |
The typical operating condition of a fan motor is: high speed, light load, low noise requirement, which aligns perfectly with the characteristics of deep groove ball bearings.
➋ Why Deep Groove Ball Bearings Are the First Choice for Fan Motors
Deep groove ball bearings are the most commonly used bearing type for fan motors for the following reasons:
| Advantages | Description |
| Low friction, high efficiency | Low rolling friction and starting torque, suitable for frequent start-stop operation |
| Low noise | Smooth operation with better noise control than other bearing types |
| Handles combined loads | Can accommodate radial loads and moderate axial loads in both directions |
| Compact design | Small footprint, ideal for the limited space in fan motors |
| Low maintenance | Sealed bearings require no regular greasing |
| Cost-effective | Reasonable cost, easy for bulk purchasing and replacement |
In small and medium-sized motors (including fan motors), sealed deep groove ball bearings are the most widely used choice.
➌ Key Selection Parameters
Ⓐ Size (Bearing Series)
The core basis for bearing selection is the motor shaft diameter. Follow these steps:
1) Determine the shaft diameter – Measure the motor shaft diameter
2) Select the inner diameter – The bearing inner diameter must match the shaft
3) Selection principle – Choose the smallest suitable size to keep manufacturing costs low and motor design compact
Common bearing sizes for fan motors:
| Motor Type | Common Shaft Diameter | Example Bearing Series |
| Small cooling fans | 3-6 mm | 683, 694, MR series |
| Household fans | 8-12 mm | F688 (8×16×4mm), 6900 series |
| Industrial fans | 15-20 mm | 6202 (15×35×11mm), 6204 |
💡 Selection principle:
Choose the smallest bearing that meets performance requirements while being economical in size and cost.
Ⓑ Precision Class
| Class | Application |
| P0 (Normal)/ABEC-1 | Standard household fans, normal noise requirements |
|
P6(ABEC-3) P5(ABEC-5) |
High speed, low noise requirements (e.g., silent fans, equipment cooling fans) |
For fan motors, P0 or P6 precision is generally sufficient, higher precision is unnecessary and adds cost.
Ⓒ Radial Clearance
| Clearance Class | Application |
| Normal (CN/C0) | Standard fans with small temperature differences |
| C3 | Large temperature differences, high speed, or possible thermal expansion (e.g., industrial fans, motor-integrated fans) |
Ⓓ Sealing Type
| Seal Type | Code | Features | Application |
| Metal shield | ZZ | Prevents solid contaminants, low friction | Clean environments, low maintenance needs |
| Rubber seal | 2RS | Dust and moisture resistant | Dusty, humid environments (e.g., outdoor fans, kitchen exhaust fans) |
| Rubber seal | 2RZ | Prevents solid contaminants, low friction | Clean environments, high speed rotating request |
| Open | OPEN | Lowest cost, requires regular greasing | Industrial equipment with scheduled maintenance |
Sealed bearings (ZZ or 2RS or 2RZ) are strongly recommended for fan motors to prevent dust ingress and extend service life.
Ⓔ Grease
The choice of grease directly affects bearing noise and lifespan:
| Grease Type | Features | Application |
| Low-noise grease | Excellent noise reduction | Household silent fans |
| High-temperature grease | Heat resistant, not easily degraded | Industrial fans, high-temperature environments |
| Wide-temperature grease | Broad adaptability | General-purpose fans |
Clearly specify "low-noise grease" requirements when selecting bearings from your supplier.
➍ Selection Recommendations for Special Applications
| Application | Recommended Configuration | Recommended Configuration |
| Household silent fan | Deep groove bearing + P6 precision + 2RS seal + low-noise grease | Low noise, dust protection, long life |
| Industrial exhaust fan | Deep groove bearing + C3 clearance + ZZ seal + high-temp grease | Heat resistance, accommodates temperature variations |
| Computer cooling fan | Micro deep groove bearing + high precision + low-torque grease | Small size, high speed, silent operation |
| Outdoor fan | Stainless steel or coated bearing + 2RS seal | Moisture and corrosion resistance |
| High-temp industrial fan (>150°C) | High-temp deep groove bearing + C5 clearance + special/solid lubricant | Heat resistance, prevents seizure |
➎ Step-by-Step Selection Summary
① Confirm Motor Parameters
• Shaft diameter
• Motor power / speed range
• Operating environment (temperature, humidity, dust)
② Select Bearing Size
• Determine inner diameter based on shaft diameter
• Determine outer diameter and width based on motor space
• Refer to bearing size charts to confirm the specific series
③ Determine Technical Grades
• Precision: P0 or P6
• Clearance: CN or C3
• Seal type: ZZ or 2RS or 2RZ
④ Confirm Lubrication
• Choose suitable low-noise grease
• Confirm whether high-temperature grease is needed
⑤ Batch Validation
• Test noise and lifespan with small sample batches
• Verify fit tolerance with the motor housing
➏ Common Selection Mistakes
| Mistake | Correct Approach |
| ❌ Bigger bearings are always better | ✅ Choose the smallest size that fits – more economical and compact |
| ❌ Higher precision is always better | ✅ Meet noise requirements without over-specifying – unnecessary cost |
| ❌ Ignoring seal type | ✅ Choose seals based on environment – sealed bearings are a must in dusty conditions |
| ❌ Overlooking grease differences | ✅ Specify noise requirements – ask your supplier for low-noise grease |
For further assistance with specific bearing selection or to request samples, please feel free to contact us as sales@welinkbearing.com.
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