71938 CD/P4AQBCD
71900 Series Super Precision Angular Contact Ball Bearings
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Part No.
Part No.
71938 CD/P4AQBCD
Basic Information
System of measurement
Metric
Weight
17.4 kg
Tolerance class
P4A
Seal type
Open
For load direction
Angular Contact
Main Dimensions
Bore diameter
190 mm
Bore diameter tolerance
-0.004mm to 0
Outside diameter
260 mm
Outside diameter tolerance
-0.004mm to 0
Width
132 mm
Width tolerance
-0.2mm to 0
Contact angle
15 °
Ball & Washer Dimensions
Ball diameter
22.225 mm
Ball quantity
28
Performance
Temperature range
- 30°C to 110 °C
Radial dynamic load rating
101025 lbf
Radial static load rating
198000 lbf
Limiting speed
16.25 X 1000 rpm
Lubrication
Lubricated
Matched arrangement
Quadruplex Back-to-Back (QBC)
Number of bearings in matched set
4
Universal matching bearing
No (Standard)
Preload
Heavy / Class D
Materials
Ring material
Chrome Steel
Ball material
Chrome Steel
Cage material
Phenolic
Technical Drawings
No drawings available at the moment, will be launched soon
In Stock
Price available upon request.
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71938 CD/P4AQBCD Bearing Product Overview & Core Advantages
The 71938 CD/P4AQBCD is a precision angular contact ball bearing designed for demanding applications requiring exceptional rigidity and load capacity. As part of a matched quadruplex set in a back-to-back arrangement, this bearing is engineered to handle combined radial and axial loads simultaneously. It features a P4A tolerance class for high running accuracy and a heavy preload (Class D) for maximum system stiffness, making it ideal for high-precision, high-reliability machinery.
71938 CD/P4AQBCD Bearing Model Code Explained, Specifications & Naming Convention
The model number 71938 CD/P4AQBCD provides detailed technical specifications:
- 71938: Basic bearing designation, indicating a metric angular contact ball bearing with a 190mm bore.
- C: Denotes a 15° contact angle, optimized for high axial load capacity.
- D: Indicates the application of a Heavy Preload (Class D) for superior rigidity.
- P4A: Specifies an ultra-precision tolerance class exceeding ABEC 7 standards, ensuring minimal runout and vibration.
- QBC: Identifies the bearing as part of a Quadruplex Back-to-Back matched set, providing exceptional moment stiffness.
71938 CD/P4AQBCD Bearing Structural Features & Performance Benefits
- High Rigidity & Load Capacity: The quadruplex back-to-back arrangement creates an extremely rigid bearing system capable of withstanding heavy combined loads and significant moment loads. The heavy preload further enhances operational stiffness.
- Precision Performance: Manufactured to P4A tolerance class with a phenolic cage, this bearing ensures high running accuracy, reduced vibration, and smooth operation at high speeds.
- Optimized for Demanding Conditions: The chrome steel rings and balls provide high durability and fatigue resistance. The open design allows for efficient lubrication management within its specified temperature range of -30°C to 110°C.
71938 CD/P4AQBCD Bearing Typical Application Areas
This high-precision, high-rigidity bearing is typically employed in:
- Machine Tool Spindles for milling, grinding, and turning centers.
- High-Speed Precision Drives and main shafts.
- Industrial Pumps and Compressors requiring high axial stiffness.
- Aerospace and Defense Positioning Systems.
