71921 ACD/HCP4A
Hybrid Ceramic Super Precision Bearings
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Basic Information
Main Dimensions
Ball & Washer Dimensions
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71921 ACD/HCP4A Bearing Product Overview & Core Advantages
The 71921 ACD/HCP4A is a single-row angular contact ball bearing engineered for applications demanding high precision and high-speed performance. Its defining feature is the 25° contact angle, which provides superior axial load capacity in one direction while accommodating combined radial and axial loads. Manufactured to a P4 (ABEC-7) tolerance class, this bearing ensures exceptional running accuracy and rotational stability. The combination of a phenolic cage and ceramic balls contributes to lower friction, reduced weight, and the capability to operate at high limiting speeds, making it an ideal solution for high-performance spindles and precision machinery.
71921 ACD/HCP4A Bearing Model Code Explained, Specifications & Naming Convention
| Code Segment | Technical Meaning |
|---|---|
| 71921 | Basic bearing series and size designation. |
| AC | Angular Contact design with a 25° contact angle. |
| D | Indicates a high-precision design. |
| HC | Refers to the Hybrid Ceramic construction (Ceramic balls with steel rings). |
| P4 | Specifies the P4 (ABEC-7) tolerance class for ultra-precise applications. |
| A | Indicates that the bearing is supplied with a specific preload. |
71921 ACD/HCP4A Bearing Structural Features & Performance Benefits
- Hybrid Ceramic Construction: The use of ceramic balls with steel rings significantly reduces centrifugal forces, lowers operating temperature, and extends service life, especially in high-speed applications.
- High-Speed Phenolic Cage: The lightweight and robust phenolic resin cage ensures dimensional stability at high rotational speeds, contributing to the bearing's limiting speed of 15,000 rpm.
- Optimized Contact Angle: The 25° contact angle is engineered to provide an excellent balance between radial and axial load carrying capacity, making it suitable for applications with significant thrust loads.
- Precision & Rigidity: Manufactured to P4 tolerance and supplied with preload, this bearing offers high system rigidity, minimal runout, and precise rotational accuracy for demanding machinery.
- Wide Temperature Range: Capable of operating in a temperature range from -30°C to 110°C, ensuring performance in various environmental conditions.
71921 ACD/HCP4A Bearing Typical Application Areas
- Machine Tool Spindles (High-speed machining centers, grinding spindles)
- Precision Robotics and Automation Equipment
- High-Frequency Motors and Spindle Drives
- Aerospace & Defense Instrumentation
- Medical Equipment (e.g., Dental handpieces, Centrifuges)
