Product structure:

The bearing model is MR85, following the internationally recognized metric numbering system for miniature bearings. The suffix “ZZ” indicates that the bearing is equipped with metal shields on both sides. Its core dimensional parameters are: Inner Diameter (d) 5 mm, Outer Diameter (D) 8 mm, Width (B) 2.5 mm. The bearing consists of an inner ring, an outer ring, a retainer (cage) assembly with high-precision stainless steel balls, and two pressed steel shields. The cage is typically made of nylon or brass for smooth operation.

Key performance features:

The MR85 ZZ bearing offers the following outstanding features: 1) Compact and Precise: Ultra-thin cross-section design saves space, ideal for compact layouts. 2) Dust and Contamination Protection: Double metal shields (ZZ) effectively prevent ingress of dust and debris, extending service life in non-hermetically sealed environments. 3) Low Friction and High Speed: The deep groove raceway combined with precision steel balls ensures low friction torque and relatively high rotational speeds. 4) Superior Material: Rings and balls are typically made from AISI 440C or similar grade stainless steel, providing good rust and corrosion resistance. 5) Easy Maintenance: Pre-lubricated design allows for maintenance-free operation in most applications without requiring additional lubrication.

Main application scenarios:

This bearing is specifically designed for applications requiring reliable rotation within extremely limited space. Typical scenarios include: supporting the shafts of miniature DC motors; serving as the spindle in drone propeller motors and micro fans; rotating components in precision measuring instruments (e.g., encoders); high-speed precision transmission parts in medical devices (e.g., dental drills); paper feed rollers and scanning head guides in office equipment; axles and gearboxes in high-precision RC models; as well as micro generators, instrument pointer shafts, and precision gear transmission systems.

Technical Specifications & Requirements:
The manufacturing and selection of MR85 ZZ bearings should adhere to the following general technical specifications: 1) Dimensional Accuracy: Typically conforms to ABEC 1 or ABEC 3 (equivalent to RBEC P0 or P6) tolerance classes, ensuring precision of inner diameter, outer diameter, and width. 2) Clearance: Usually supplied with standard radial clearance for miniature bearings (e.g., C0 group). Other clearance groups are available upon request. 3) Lubrication: Factory pre-lubricated with a small amount of high-speed oil or grease. Users should verify suitability based on actual speed, load, and temperature conditions. Special high-speed bearing grease can be replenished if necessary. 4) Load and Speed: Dynamic load rating (Cr) and static load rating (C0r) are relatively low, suitable for light-load applications. The limiting speed depends on lubrication and heat dissipation conditions. 5) Installation Requirements: Ensure concentricity and perpendicularity of the shaft and housing during installation to avoid deformation from improper hammering. Using dedicated tools for press-fitting is recommended.

Obtain Certificate / 证书:

About US / 关于我们