71918 ACD/P4ATBTB
71900 Series Super Precision Angular Contact Ball Bearings
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71918 ACD/P4ATBTB Bearing Product Overview & Core Advantages
The 71918 ACD/P4ATBTB is a super-precision angular contact ball bearing supplied as a triplex back-to-back (TBT) matched set. Engineered to the exacting P4A tolerance class, this bearing is designed for applications demanding exceptional rotational accuracy, high system rigidity, and the ability to handle significant combined loads (radial and axial). Its 25° contact angle and matched set configuration provide outstanding operational stability and positioning precision in high-performance machinery.
71918 ACD/P4ATBTB Bearing Model Code Explained, Specifications & Naming Convention
- 71918: Basic series and size designation (90mm bore, 125mm OD, 54mm width).
- A: Denotes a 25° contact angle, optimized for high axial load capacity.
- CD: Indicates a triplex set with universal matching for precise load sharing.
- P4A: Specifies an ultra-precision tolerance class superior to ABEC 7, ensuring minimal runout and vibration.
- TBT: Defines the matched arrangement as Triplex Back-to-Back, which maximizes moment rigidity and stability.
- Light Preload / Class B: The bearings are preloaded to eliminate internal clearance, enhancing stiffness and rotational accuracy from startup.
71918 ACD/P4ATBTB Bearing Structural Features & Performance Benefits
High Rigidity & Moment Load Capacity: The triplex back-to-back (TBT) arrangement creates a wide, rigid support system that effectively resists moment loads and tilting moments, making it ideal for spindle applications.
Superior Load Ratings: With a dynamic load rating of 21,510 lbf and a static load rating of 32,175 lbf, this bearing set is built to handle demanding combined radial and axial loads.
Optimized for High-Speed Operation: The lightweight phenolic resin cage reduces centrifugal forces, while the precision-ground chrome steel components and optimized internal geometry contribute to a high limiting speed of 15,000 rpm.
Pre- Lubricated for Immediate Service: The bearing is factory-lubricated and ready for installation, ensuring optimal performance within its specified temperature range of -30°C to 110°C.
71918 ACD/P4ATBTB Bearing Typical Application Areas
This high-precision bearing set is typically specified for the most demanding applications, including:
- Machine Tool Spindles: For CNC milling centers, grinding spindles, and lathes requiring high rigidity and accuracy.
- High-Frequency Machining Centers: Where high rotational speeds and minimal runout are critical.
- Precision Grinding Equipment: To ensure superior surface finishes and dimensional consistency.
- Industrial Pumps and Compressors: For high-speed rotor support in demanding fluid handling systems.
