71938 ACD/P4ATBTC
71900 Series Super Precision Angular Contact Ball Bearings
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71938 ACD/P4ATBTC Bearing Product Overview & Core Advantages
The 71938 ACD/P4ATBTC is a metric system, triplex back-to-back (TBT) matched set of precision angular contact ball bearings designed for applications demanding exceptional rigidity and accuracy. Operating under P4A tolerance class, this configuration delivers superior high rigidity and load-carrying capacity, making it ideal for handling combined loads (radial and axial) in demanding environments. The set's moderate preload (Class C) ensures precise shaft positioning and optimal performance in high-speed, high-precision machinery. Its open design, lubricated for immediate operation, supports a broad temperature range from -30°C to 110°C.
71938 ACD/P4ATBTC Bearing Model Code Explained, Specifications & Naming Convention
| Code Segment | Technical Meaning |
|---|---|
| 71938 | Basic bearing designation, indicating the bearing size with a 190mm bore and 260mm outside diameter. |
| ACD | Angular Contact Design with a 25° contact angle for optimal axial load capacity. |
| P4A | Indicates a high-precision tolerance class for both inner and outer rings, ensuring minimal runout and vibration. |
| TBT | Specifies the Triplex Back-to-Back matched arrangement of three bearings, providing maximum rigidity against moment loads. |
| C | Denotes the Moderate Preload (Class C) applied to the matched set for enhanced stiffness and rotational accuracy. |
71938 ACD/P4ATBTC Bearing Structural Features & Performance Benefits
Optimized Rigidity and Load Capacity: The triplex back-to-back (TBT) arrangement of three bearings creates an exceptionally high rigidity system, effectively resisting complex combined loads and moment forces. This makes it suitable for applications where shaft deflection must be minimized.
Precision and High-Speed Performance: Manufactured to P4A tolerance class with a phenolic cage, this bearing set ensures smooth operation and low vibration at high speeds, with a limiting speed of 11,000 rpm. The 25° contact angle is optimized for carrying significant axial loads in addition to radial loads.
Durable Construction: The use of chrome steel for both rings and balls, combined with a robust phenolic cage, ensures long service life and reliability under demanding operating conditions.
Ready for Operation: The bearings are pre-lubricated, allowing for immediate installation and initial operation, simplifying the assembly process.
71938 ACD/P4ATBTC Bearing Typical Application Areas
This high-precision, high-rigidity bearing set is engineered for critical applications in:
- Machine Tool Spindles: For high-speed milling, grinding, and turning centers requiring extreme accuracy and stiffness.
- Precision Gearboxes: Especially in industrial robotics and high-torque transmission systems.
- High-Frequency Motors and Spindles: Where minimal runout and high rotational speeds are paramount.
- Aerospace Test Rigs and Positioning Systems: Demanding the reliability of a matched bearing set under complex loading.
