71811 ACD/P4QBCB
71800 Series Super Precision Angular Contact Ball Bearings
Image may differ from product. See technical specification for details.
Part No.
Part No.
71811 ACD/P4QBCB
Basic Information
System of measurement
Metric
Weight
0.32 kg
Tolerance class
P4
Seal type
Open
For load direction
Angular Contact
Main Dimensions
Bore diameter
55 mm
Bore diameter tolerance
-0.004mm to 0
Outside diameter
72 mm
Outside diameter tolerance
-0.004mm to 0
Width
36 mm
Width tolerance
-0.2mm to 0
Contact angle
25 °
Ball & Washer Dimensions
Ball diameter
4.762 mm
Ball quantity
29
Performance
Temperature range
- 30°C to 110 °C
Radial dynamic load rating
5738 lbf
Radial static load rating
9112 lbf
Limiting speed
34 X 1000 rpm
Lubrication
Lubricated
Matched arrangement
Quadruplex Back-to-Back (QBC)
Number of bearings in matched set
4
Universal matching bearing
No (Standard)
Preload
Light / Class B
Materials
Ring material
Chrome Steel
Ball material
Chrome Steel
Cage material
Phenolic
Technical Drawings
No drawings available at the moment, will be launched soon
In Stock
Price available upon request.
Our sales team will respond within 24 hours with a competitive quote tailored to your requirements.
REQUEST A QUOTE
- Fast delivery
- Enjoy discounts on bulk purchases
- Secure Payment
- Fast Global Shipping
Product Overview and Core Advantages
The 71811 ACD/P4QBCB is a metric precision angular contact ball bearing configured in a quadruplex back-to-back (QBC) matched arrangement. This setup is engineered for applications demanding exceptional rigidity and the ability to handle significant combined loads, including radial and axial loads in both directions. Manufactured to a P4 tolerance class and featuring a light preload (Class B), this bearing delivers high running accuracy and stability, making it ideal for high-precision, high-reliability machinery.
71811 ACD/P4QBCB Bearing Model Code Explained, Specifications & Naming Convention
| Suffix Code | Technical Meaning |
|---|---|
| ACD | Angular Contact Design with a 25° contact angle. |
| P4 | Indicates a high-precision tolerance class for superior running accuracy. |
| QBC | Specifies a Quadruplex Back-to-Back matched set of four bearings. |
| B | Denotes a Light Preload (Class B) for optimal stiffness and minimal deflection. |
Structural Features and Performance Benefits
- Exceptional Rigidity and Load Capacity: The quadruplex back-to-back arrangement creates a highly rigid bearing system capable of supporting substantial combined radial and axial loads from any direction. This configuration effectively resists moment loads, ensuring shaft stability.
- High-Speed Capability: The phenolic cage is lightweight and robust, contributing to lower centrifugal forces and stable operation at high rotational speeds, with a limiting speed of 34,000 rpm.
- Precision Performance: Manufactured to P4 tolerance standards with a 25° contact angle, this bearing guarantees high running accuracy, low noise, and minimal vibration.
- Durable Construction: Components made from chrome steel provide high fatigue life and wear resistance, ensuring long-term reliability in demanding conditions.
71811 ACD/P4QBCB Bearing Typical Application Areas
This bearing is specifically designed for high-performance applications where maximum rigidity and precision are paramount. Key industries and equipment include:
- Machine Tool Spindles: For high-speed milling, grinding, and turning centers.
- Precision Gearboxes: Especially in robotics and high-torque transmission systems.
- Industrial Pumps and Compressors: Where reliable operation under combined loads is critical.
- Aerospace and Defense Systems: For actuators, control surfaces, and other precision mechanisms.
