71904 ACD/P4A
71900 Series Super Precision Angular Contact Ball Bearings
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71904 ACD/P4A Bearing Product Overview & Core Advantages
The 71904 ACD/P4A is a single-row angular contact ball bearing designed for applications demanding exceptional rotational accuracy and high-speed capability. Engineered to a P4 (ABEC-7) tolerance class, it is a quintessential precision bearing. Its primary function is to support combined loads, carrying significant radial loads and axial loads in one direction simultaneously. The optimized 25° contact angle provides an excellent balance between axial load capacity and high-speed performance. This bearing is preloaded, ensuring high system rigidity and minimal axial and radial runout, making it ideal for high-precision, high-reliability spindles and machinery.
71904 ACD/P4A Bearing Model Code Explained, Specifications & Naming Convention
| Code Segment | Technical Meaning |
|---|---|
| 71904 | Basic bearing series designation, indicating a light series, 20mm bore angular contact bearing. |
| AC | Angular Contact design with a 25° contact angle. |
| D | Signifies a high-precision design with a high ball count and optimized internal geometry. |
| P4 | Indicates the tolerance class is P4 (equivalent to ABEC-7), ensuring extremely tight dimensional and running accuracy. |
| A | Denotes that the bearing is supplied with a specific preload for immediate high-rigidity performance. |
71904 ACD/P4A Bearing Structural Features & Performance Benefits
- High Rigidity & Precision: The combination of a P4 tolerance class and factory-applied preload ensures maximum system stiffness and precise shaft positioning, critical for minimizing deflection under load.
- Optimized Load Capacity: The 25° contact angle is engineered to efficiently handle combined loads, providing superior axial load capacity while maintaining high radial load ratings.
- Superior High-Speed Performance: The lightweight phenolic resin cage reduces centrifugal forces, while the high-grade chrome steel construction ensures dimensional stability, contributing to a high limiting speed of 60,000 rpm.
- Material Excellence: Manufactured from high-purity chrome steel for rings and balls, the bearing offers high hardness, wear resistance, and a long operational life under demanding conditions.
71904 ACD/P4A Bearing Typical Application Areas
- Machine Tool Spindles: High-speed milling, grinding, and turning centers.
- Precision Instrumentation: High-accuracy measuring devices and optical scanners.
- High-Frequency Motors & Spindles: Motors for PCB drilling and dental handpieces.
- Robotics: High-precision joints and actuators.
