1 Complete Model & Code Explanation

Model: 7015 CE/HCP4AQBCA

Code Definition

7015: Basic dimension of 70 series light-duty single-row angular contact ball bearing

CE: 25° nominal contact angle, machined solid brass cage, outstanding axial load capacity

HC: Hybrid ceramic construction, rolling elements made of silicon nitride Si₃N₄ ceramic balls, inner & outer rings in bearing steel

P4AQBCA: Upgraded ISO P4 super precision standard with stricter control over rotational runout, vibration grade and factory cleanliness; QBCA stands for clean manufacturing and low-noise delivery specification

Supply form: Single independent bearing, without factory duplex matching

Important reminder: This is single unit bearing without factory end grinding matching. If duplex or triplex arrangement is required, precision spacers must be selected on-site to adjust preload. Do not simply assemble two bearings to replace factory matched duplex sets.

Suffix Comparison within Series

7015 CE/P4A: Single bearing, 25° contact angle, all steel balls, standard P4A precision

7015 CE/HCP4A: Single bearing, 25° contact angle, HC silicon nitride ceramic balls, basic P4A precision

7015 CE/HCP4AQBCA: Single bearing, 25° contact angle, HC ceramic balls, upgraded clean low-noise P4AQBCA spec (this model)

7015 CD/HCP4AQBCA: Single bearing, 15° contact angle, HC ceramic balls, P4AQBCA clean precision

Core Basic Dimensions

Bore d: 75 mm

Outer diameter D: 115 mm

Width B: 20 mm

Structure: Single-row open-type angular contact ball bearing, supplied as separate single unit

Rolling element: Si₃N₄ silicon nitride ceramic ball (HC hybrid ceramic configuration)

Ring material: High-carbon chromium bearing steel, ultra-precision mirror grinding on raceway

Cage: Machined solid brass cage

Outer ring feature: Standard plain outer ring without integrated oil-air lubrication grooves

Pre-filled lubricant: None

Delivery form: Individually packed single unit, no matching serial number

Note: Official dynamic load rating and limiting DN data can be requested from manufacturer.

Full Product Attributes

Contact form: Two-point contact

Number of rows: Single row, single unit without factory pairing

Pairing property: Independent single bearing, support on-site spacer assembly for DB/DF/DT layout

Precision class: P4AQBCA upgraded clean-type P4 super precision high-speed grade

Material: Inner & outer rings: high-carbon chromium bearing steel; rolling elements: silicon nitride ceramic balls (hybrid ceramic)

Seal structure: Open type, non-sealed

Special construction: Ceramic rolling elements with insulation against electrocorrosion, low density & low friction, low heat rise under high speed

Note: CE represents 25° large contact angle with stronger axial load capacity and better resistance against axial cutting load compared with 15° CD series, accompanied by slightly higher friction at same rotating speed. HC ceramic balls feature much lower density than steel, sharply reduced centrifugal force, enabling higher limiting DN value and lower temperature rise during continuous high-speed operation. Meanwhile ceramic material provides insulation property to block shaft current generated by variable frequency motors and prevent electrocorrosion pits and raceway waviness damage. P4AQBCA implements stricter standards for factory cleaning, clean packaging and vibration screening than basic P4A grade, suitable for high-end precision spindles. Open structure prioritizes oil-air forced lubrication; long-term continuous high-speed grease lubrication is not recommended.

2 Structure & Operating Characteristics

Japan NMT 7015 CE/HCP4AQBCA is P4AQBCA super precision single open-type hybrid silicon nitride ceramic ball angular contact ball bearing of 7015 series with 25° contact angle. Inner and outer rings adopt high-carbon chromium bearing steel with stabilized heat treatment to eliminate internal residual stress. Raceways are processed via multi-process ultra-precision mirror finishing for uniform surface quality, realizing low-vibration and low-noise rotation.

Rolling elements adopt high-purity silicon nitride ceramic balls featuring high hardness, light weight and low friction coefficient. Compared with all-steel bearings of identical size, heat generation is greatly reduced under high speed and higher maximum rotating speed is permitted. Ceramic rolling elements are naturally insulated, effectively suppressing electrocorrosion pits and channel waviness caused by shaft current commonly found in variable frequency high-speed motor spindles.

Matched machined solid brass cage maintains good dimensional stability and creep resistance under high temperature, suitable for 24-hour non-stop high-speed engraving, milling and graphite cutting production.

The bearing is single open-type design; no sealing parts to cut friction loss. Plain standard outer ring fits spindles adopting built-in housing oil channels. No pre-matching at factory. Machine manufacturers can select spacers freely according to rigidity and speed requirements to form DB back-to-back, DF face-to-face, DT tandem arrangement, and set light, medium, heavy preload flexibly.

3 Core Performance Advantages

1. CE 25° large contact angle: Excellent axial load capacity, capable of sustaining large unidirectional and alternating axial cutting loads with prominent axial rigidity.

2. HC silicon nitride hybrid ceramic balls: Light weight, low centrifugal force, drastically elevated limiting DN value; lower temperature rise during operation and outstanding wear resistance; insulation function protects against shaft current electrocorrosion.

3. P4AQBCA clean upgraded precision grade: Strict control over rotational runout, factory cleanliness and vibration indicators, reducing spindle vibration and improving finished surface quality.

4. Flexible single-unit assembly: No fixed factory pairing. Users may combine with spacers freely and configure DB/DF/DT layout on demand, adapting to various preload design schemes.

5. Open non-sealed construction: Eliminates seal friction loss, fully compatible with oil-air forced lubrication and circulating oil cooling lubrication systems.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

P4AQBCA super precision bearings must be assembled in constant-temperature dust-free clean workshops. Completely remove all burrs and debris on shaft and housing fitting surfaces. Controlled thermal mounting method is recommended; open-flame heating, direct striking of bearing rings are forbidden to avoid indentation damage on raceways.

Important reminder: This is independent single bearing without factory pairing relation. Two bearings of same model cannot be directly assembled to substitute factory pre-matched sets. If duplex configuration is required, precision ground spacers must be equipped and preload load controlled accurately via axial clamping amount.

5.2 Pairing & Preload Instructions

Supply condition: Individually packed single bearing, no matching serial number.

Optional assembly layout: DB back-to-back / DF face-to-face / DT tandem realized with precision spacers.

Selection tips:

Ultra-high speed, variable frequency motor, risk of shaft current → Prioritize HC ceramic ball model 7015 CE/HCP4AQBCA;

Focus on radial rigidity, medium rotating speed, no electrocorrosion risk → Select CD contact angle series bearings;

Heavy axial load, low rotating speed → 25° contact angle all-steel duplex bearings;

Prototype development requiring flexible preload adjustment → Single ceramic ball bearing this model.

Selection reference:

① Single bearing, 25°, all steel balls, standard precision →7015 CE/P4A

② Single bearing, 25°, HC ceramic balls, basic P4A →7015 CE/HCP4A

③ Single bearing, 25°, HC ceramic balls, clean low-noise upgraded P4AQBCA →7015 CE/HCP4AQBCA(this model)

④ Single bearing, 15°, HC ceramic balls, clean low-noise upgraded P4AQBCA →7015 CD/HCP4AQBCA

5.3 Lubrication Matching Scheme

No pre-filled grease. Oil-air forced circulation lubrication is preferred; circulating oil lubrication is also acceptable. Long-duration continuous high-speed grease lubrication is not suggested. High-precision filters shall be installed in lubrication pipelines. Hard impurities will easily scratch mirror raceways and ceramic ball surfaces. Mixing lubricants from different brands or base oil types is prohibited. Replace filter elements regularly to maintain lubricant cleanliness and extend bearing service life. Ceramic balls own extremely high hardness; hard particle contamination will trigger continuous abrasion on raceways.

5.4 Speed Parameter Note

HC ceramic ball structure greatly reduces centrifugal load under high speed, allowing far higher DN value than same-size all-steel bearings, suitable for long-term continuous ultra-high speed operation. Even though ceramic balls generate less heat, the whole machine should be equipped with sufficient cooling system and adequate speed safety margin. Open bearings have no built-in dust prevention. Bearing housing must adopt reliable external sealing against dust and cutting fluid to avoid abrasion on rolling elements and raceways caused by foreign matter intrusion.

6 Daily Maintenance & Fault Troubleshooting

After bearing assembly, implement multi-stage low-speed running-in, continuously monitor temperature rise and vibration data. Raise rotating speed to rated value only after all indicators stabilize. Closely track spindle temperature variation during running-in period. Regularly inspect external housing sealing condition, lubrication pipeline pressure and flow rate to guarantee stable continuous oil supply.

When persistent abnormal noise, rapid temperature rise or growing vibration occurs, check sequentially: lubricant cleanliness, assembly coaxial precision, excessive axial clamping force, external impact load, dust or cutting fluid intrusion into bearing interior, failure of shaft current protection.

Typical failure modes of hybrid ceramic bearings include raceway fatigue spalling, abrasive wear, overheating caused by insufficient lubrication, edge loading due to misalignment, uneven preload induced by low-precision spacers, chipping and cracking of ceramic balls caused by edge impact. Establish regular online monitoring system for temperature and vibration to detect early damage and prevent unexpected spindle shutdown.