71938 CD/P4ADBB
71900 Series Super Precision Angular Contact Ball Bearings
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71938 CD/P4ADBB Bearing Product Overview & Core Advantages
The 71938 CD/P4ADBB is a precision duplex angular contact ball bearing designed for applications demanding exceptional rotational accuracy and rigidity. This metric system bearing features a Back-to-Back (DB) matched arrangement and a P4A super-precision tolerance class, making it ideal for high-speed spindles and other precision machinery. Its primary advantage lies in its ability to support combined loads (radial and axial) simultaneously while maintaining high operational stability under a light preload (Class B). The open design, combined with a phenolic cage, facilitates high-speed operation and efficient lubrication.
71938 CD/P4ADBB Bearing Model Code Explained, Specifications & Naming Convention
| Code Segment | Technical Meaning | Significance |
|---|---|---|
| 71938 | Basic bearing series and size designation | Indicates a high-precision angular contact bearing with a 190mm bore. |
| C | 15° Contact Angle | Optimized for supporting significant axial loads in combination with radial loads. |
| D | Duplex Arrangement | Two bearings are supplied as a matched set. |
| P4A | Tolerance Class | Denotes super-precision levels for bore, outer diameter, and width tolerances, ensuring minimal runout and vibration. |
| DB | Back-to-Back Mounting | The two bearings are matched to be mounted back-to-back, providing high moment stiffness and accommodating axial loads from both directions. |
| B | Light Preload | The matched set is preloaded to eliminate internal clearance, enhancing rigidity and rotational accuracy from startup. |
71938 CD/P4ADBB Bearing Structural Features & Performance Benefits
High Rigidity and Stability: The duplex back-to-back (DB) arrangement creates a rigid bearing system that can withstand high moment loads, making it exceptionally stable under complex operating conditions.
Superior Load Capacity: With a 15° contact angle and a high dynamic load rating of 62,100 lbf, this bearing is engineered to handle significant combined radial and axial loads efficiently.
Optimized High-Speed Performance: The phenolic resin cage is lightweight and robust, contributing to lower centrifugal forces and smoother operation at high speeds, up to a limiting speed of 16,250 rpm. The open seal type allows for effective lubrication management in high-speed applications.
Precision Engineering: Manufactured to P4A tolerance class with tight dimensional control on bore, outer diameter, and width, this bearing ensures minimal vibration and superior running accuracy for precision machinery.
71938 CD/P4ADBB Bearing Typical Application Areas
The 71938 CD/P4ADBB is specifically designed for high-performance applications where precision, speed, and rigidity are paramount. Key industries and equipment include:
- Machine Tool Spindles: High-speed milling, grinding, and turning centers.
- Precision Grinding Spindles: Applications requiring ultra-fine surface finishes.
- High-Frequency Machining Centers: For demanding metal cutting operations.
- Industrial Pumps and Compressors: Where reliable performance under combined loads is critical.
