71911 ACD/P4AQBCA
71900 Series Super Precision Angular Contact Ball Bearings
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Part No.
Part No.
71911 ACD/P4AQBCA
Basic Information
System of measurement
Metric
Weight
0.72 kg
Tolerance class
P4A
Seal type
Open
For load direction
Angular Contact
Main Dimensions
Bore diameter
55 mm
Bore diameter tolerance
-0.004mm to 0
Outside diameter
80 mm
Outside diameter tolerance
-0.004mm to 0
Width
52 mm
Width tolerance
-0.2mm to 0
Contact angle
25 °
Ball & Washer Dimensions
Ball diameter
7.938 mm
Ball quantity
23
Performance
Temperature range
- 30°C to 110 °C
Radial dynamic load rating
10980 lbf
Radial static load rating
12375 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
Extra light / Class A
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.
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71911 ACD/P4AQBCA Bearing Product Overview & Core Advantages
The 71911 ACD/P4AQBCA is a precision angular contact ball bearing configured as a Quadruplex Back-to-Back (QBC) matched set. Engineered to the exacting P4A tolerance class, this bearing is designed for applications demanding exceptional rotational accuracy and system rigidity. Its primary advantage lies in its ability to support combined loads—handling significant radial loads and thrust loads in both directions simultaneously. The matched set configuration provides pre-defined preload (Extra light / Class A), ensuring optimal stiffness and rotational precision right from installation, making it ideal for high-speed, high-precision machinery.
71911 ACD/P4AQBCA Bearing Model Code Explained, Specifications & Naming Convention
| Code Segment | Technical Meaning |
|---|---|
| 71911 | Basic bearing series and size designation (55mm bore, 80mm OD, 52mm width). |
| ACD | Angular Contact design with a 25° contact angle. |
| P4A | Indicates a high-precision tolerance class for both inner and outer rings, exceeding standard ABEC 7/ISO P4 levels. |
| QBC | Specifies the bearing is supplied as a Quadruplex Back-to-Back matched set of four bearings. |
71911 ACD/P4AQBCA Bearing Structural Features & Performance Benefits
- High Rigidity & Load Capacity: The Quadruplex Back-to-Back (QBC) arrangement creates a highly rigid bearing system capable of withstanding heavy combined loads and moment loads. The 25° contact angle is optimized for supporting substantial thrust loads in both directions.
- Precision & High-Speed Performance: Manufactured to P4A tolerance class for minimal runout and vibration. The phenolic cage and optimized internal geometry contribute to stable operation at high speeds, with a limiting speed of 34,000 rpm.
- Superior Material & Construction: Components are made from chrome steel for high durability and fatigue resistance. The set is pre-lubricated, ensuring immediate operational readiness and protection during the initial run-in period.
- Simplified Installation: The bearings are supplied as a factory-matched set with a pre-defined Extra light preload. This eliminates complex calculations and adjustments during installation, guaranteeing consistent, high-performance operation.
71911 ACD/P4AQBCA Bearing Typical Application Areas
This precision matched bearing set is ideally suited for high-performance applications requiring maximum rigidity and accuracy, including:
- Machine Tool Spindles: High-speed milling, grinding, and turning centers.
- Precision Gearboxes: Where low noise and high positional accuracy are critical.
- High-Frequency Spindles: PCB drilling and routing machines.
- Robotic Drives: High-accuracy rotary joints and actuators.
