Hybrid bearing SS-MR115 ZZ

SS-MR115 ZZ is a high-performance hybrid bearing featuring AISI440 stainless steel rings, Si₃N₄ (silicon nitride) ceramic balls, and an AISI304 stainless steel cage. The ceramic balls offer low density, high strength, low friction, electrical and magnetic resistance, excellent wear resistance, and high rigidity. This hybrid design enables lubrication-free or maintenance-free operation, making it ideal for high-speed applications where reliability and durability are critical. The ZZ metal shields provide effective contamination protection.

◆ Basic Dimensions and Weight

Model SS-MR115 ZZ (standard MR115 series). Dimensions in mm, weight in kg.

Mounting dimensions: da min = 6.5 mm, Da max = 9.5 mm, ra max = 0.2 mm.
   Reference weight: 0.002 kg (hybrid construction).

◆ Material and Design

● Rings – AISI440 Stainless Steel – Martensitic stainless steel with high hardness (58–60 HRC) and excellent wear resistance. Provides good corrosion resistance for moderate environments.

● Balls – Si₃N₄ (Silicon Nitride) – Advanced ceramic offering low density (~3.2 g/cm³), high strength, high fracture toughness, and exceptional wear resistance. Non-magnetic, electrically insulating, and capable of dry running.

● Cage – AISI304 Stainless Steel – Austenitic stainless steel cage provides good corrosion resistance, strength, and stability at moderate temperatures. Ribbon-type or crown-type design ensures low friction and reliable ball guidance.

● Shields – ZZ (Metal Shields, Both Sides) – Non-contact metal shields protect the bearing from particulate contamination while maintaining high-speed capability and low torque.

◆ Core Performance Advantages

● High-Speed Capability – The lightweight Si₃N₄ balls reduce centrifugal forces, enabling speeds significantly higher than all-steel bearings. Ideal for high-rpm applications.

● Low Friction & Heat Generation – Ceramic balls have a very low friction coefficient (0.03–0.08) and generate less heat, improving efficiency and extending grease life.

● Electrical & Magnetic Insulation – Si₃N₄ is non-conductive and non-magnetic, preventing current-induced damage (electrolytic corrosion) and maintaining signal integrity in sensitive equipment.

● Wear Resistance & Durability – Silicon nitride balls offer superior wear resistance compared to steel, extending bearing life under abrasive or contaminated conditions.

● Rigidity & Precision – The hybrid construction provides high radial and axial rigidity, ensuring stable rotation and accuracy under load.

● Lubrication & Maintenance Flexibility – Can operate with standard grease, oil, or dry (no lubrication) in many applications, reducing maintenance frequency and costs.

◆ Application Areas

● High-Speed Spindles – PCB drilling, dental drills, small CNC spindles – where high rpm and low vibration are required.

● Medical & Dental Equipment – Surgical handpieces, laboratory centrifuges – biocompatible and capable of dry running.

● Semiconductor & Cleanroom – Vacuum robots, wafer handling – non-magnetic and particle-free.

● Aerospace & Defense – Instrumentation, gyroscopes, actuator mechanisms – lightweight and reliable.

● Electric Motors & Generators – Preventing electrical arcing and current-induced bearing damage.

● Precision Instruments – Measuring equipment, optical scanners, and other high-precision devices.

◆ Technical Data