S71904 ACD/P4ADBC
Sealed Super Precision Angular Contact Ball Bearings
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S71904 ACD/P4ADBC Bearing Product Overview & Core Advantages
The S71904 ACD/P4ADBC is a precision duplex back-to-back angular contact ball bearing designed for demanding applications requiring high rigidity and exceptional running accuracy. This matched pair bearing set is pre-loaded to Moderate / Class C specifications, delivering superior system stability and minimizing axial and radial runout. Its compact design, featuring a 20 mm bore and 37 mm outside diameter, is engineered to handle combined loads efficiently, making it an ideal solution for high-precision, high-reliability machinery where space is at a premium.
S71904 ACD/P4ADBC Bearing Model Code Explained, Specifications & Naming Convention
| Code Segment | Technical Meaning | Significance |
|---|---|---|
| S7 | Bearing Series | Indicates a high-precision angular contact ball bearing series. |
| 1904 | Size Code | Specifies the bore diameter (20 mm), outside diameter (37 mm), and width (18 mm). |
| ACD | Contact Angle & Arrangement | A 25° contact angle and a Duplex Back-to-Back (DB) arrangement, providing high moment rigidity. |
| P4A | Tolerance Class | Denotes a very high precision grade, exceeding ABEC 7 standards, for exceptional dimensional and running accuracy. |
| DBC | Internal Clearance/Preload | Specifies a moderate preload (Class C) for optimal stiffness and performance in the matched set. |
S71904 ACD/P4ADBC Bearing Structural Features & Performance Benefits
High Rigidity and System Stability: The duplex back-to-back (DB) arrangement of the two bearings creates a pre-loaded system that is exceptionally resistant to moment loads, ensuring maximum shaft positioning accuracy and high rigidity.
Superior Load Capacity: With a 25° contact angle and a robust construction using chrome steel rings and balls, this bearing is engineered to sustain significant combined radial and axial loads simultaneously.
High-Speed Capability: The lightweight and durable phenolic resin cage minimizes centrifugal forces, reduces friction, and contributes to a high limiting speed of 100,000 rpm, making it suitable for high-speed spindle applications.
Sealed and Lubricated for Life: As a sealed bearing pre-lubricated with grease, it is protected from contamination and is designed for long-term, maintenance-free operation within its specified temperature range.
S71904 ACD/P4ADBC Bearing Typical Application Areas
The S71904 ACD/P4ADBC is ideally suited for high-precision machinery and systems where accuracy, speed, and rigidity are paramount. Key applications include:
- Machine Tool Spindles: High-speed machining centers, grinding spindles, and CNC lathes.
- Precision Instrumentation: Measuring devices, optical scanners, and coordinate measuring machines (CMM).
- High-Frequency Spindles: PCB drilling and routing spindles.
- Robotics: High-accuracy joints and arm assemblies.
