From the nimble wrists of minimally invasive surgical robots to the silent rotation of artificial hip joints, millimeter-level bearings are quietly driving a revolution in medical technology with their astonishing precision and reliability.
In modern medicine, bearings, though small, bear the weight of life. These precision components not only physically support the operation of equipment but also serve as the core technology that overcomes multiple technical challenges, including biocompatibility, aseptic operation, and precision control.
When surgical robot arms suture blood vessels with 0.1-degree precision, when MRI equipment rotates without interference in strong magnetic fields, and when nanorobots deliver targeted drugs in the bloodstream-all these are silently supported by specialized medical bearing technology. The following information will provide you with an understanding of the bearing characteristics and typical models used in different medical equipment applications:
1. General-Purpose Medical Deep Groove Ball Bearings (Basic Sealed Protection)
This type of bearing primarily features double-sided rubber seals (2RS), ensuring both fluid protection and low friction.
6800-2RS
Dimensions: 10 mm × 19 mm × 5 mm
Features: Medical-grade design, stainless steel (AISI 304/440C), with contact seals to prevent blood stains and disinfectant intrusion during surgery.
Applications: Rotating shafts for surgical instruments, adjustment mechanisms for medical electric chairs.
694-2RS
Dimensions: 4 mm × 11 mm × 4 mm
Features: Miniature design fits compact spaces. Made of GCr15 steel with a chrome-plated surface or all stainless steel, with a maximum speed of 40,000 rpm, it meets the drive requirements of dental drills and endoscopes.
Applications: Motor spindles for handheld surgical tools, joints for minimally invasive surgical instruments.
627-2RS
Dimensions: 7 mm × 22 mm × 7 mm
Features: EMQ-grade (motor-specific) precision, Z3 quietness rating, PTFE-reinforced seals, IP54 dust and water resistance rating.
Applications: Power transmission modules for electric bone saws and high-frequency electrosurgical units.
2.Bearing Applications in Prostheses and Exoskeletons
Miniature Deep Groove Ball Bearings (for Finger/Hand Joints)
694-2RS
Dimensions: 4 mm (inner diameter) × 11 mm (outer diameter) × 4 mm (thickness)
Features: Double-sided rubber seals (2RS) protect against dust and body fluids; silent design, low friction coefficient; Made of bearing steel (GCr15) or stainless steel (304/440), with surface passivation for enhanced corrosion resistance.
Applications: Prosthetic finger hinges, miniature rotary joints.
696-ZZ/2RS
Dimensions: 6 mm × 15 mm × 5 mm
Features: Optional double-sided metal dust caps (ZZ) or rubber seals (2RS); Maximum speed 32,000 rpm (grease lubrication), dynamic load 1.35 kN; Stainless steel versions (such as 440) are suitable for prosthetic limbs exposed to sweat.
Applications: Wrist rotation mechanisms, lightweight prosthetic transmission components.
F688-2RS
Dimensions: 8 mm × 18 mm × 1 mm (with flange)
Features: The flange design facilitates axial fixation and reduces installation space; double-sided seals prevent grease leakage, making it suitable for joints with frequent movements.
Applications: Compact prosthetic shafts and adjustable angle joints.
3.Bearing Applications in Ventilators
When intrinsic lung function declines, ventilators keep patients alive. Our bearings play an essential role in this regard. Deep groove ball bearings are primarily used in core moving parts such as motor drive systems, turbofans, and valve control mechanisms. They must meet stringent requirements for sterile environment compatibility, low noise, maintenance-free operation, and high-speed stability.
The turbofans in ventilators require extremely high speeds (typically 20,000–50,000 rpm) to maintain stable airflow. Therefore, bearings must be compact, low-friction, and leak-tight.
618/8-2RS
Dimensions: 8 mm (inner diameter) × 16 mm (outer diameter) × 4 mm (thickness)
Features: Double-sided rubber seals (2RS) provide protection against body fluids and disinfectants; grease lubrication, operating speeds up to 42,000 rpm, and dynamic loads up to 1.60 kN; stainless steel (AISI 304/440C) certified for biocompatibility according to ISO 10993. Applications: Turbocharger fan main shaft, micro DC motor rotor support.
694-2RS
Dimensions: 4 mm × 11 mm × 4 mm
Features: Maximum speed 40,000 rpm, quietness level Z3; optional ceramic balls (silicon nitride) reduce friction by 40%, reducing motor heat.
Applications: Micromotor drive shaft for oxygen flow control valves.
D/WR1-5-2Z (Ultra-Micro)
Dimensions: 2.38 mm × 7.938 mm × 3.571 mm
Features: Bimetallic dust cover (ZZ), oil lubrication, speed 160,000 rpm; DLC coating on GCr15 steel increases wear life by three times.
Applications: Precision rotating components in sensor feedback mechanisms.
4.Bearing Applications in Dental Technology
In the dental field, deep groove ball bearings are primarily used in high-speed dental drill handpieces, drive systems for dental treatment units, and dental imaging equipment. They must meet stringent requirements such as ultra-high speed, compatibility with sterile environments, low noise, and long life.
SR144 Series (Core High-Speed Model)
Dimensions: 3.175 × 6.35 × 2.38 mm (Industry-standard interface, compatible with mainstream dental handpieces)
Speed: 350,000–450,000 rpm (measured at 250 kPa)
Noise: ≤65–70 dB (elastic bearing structure + ceramic ball noise reduction design)
Material: Rings: 440C stainless steel (vacuum heat-treated, hardness HRC 60+)
Rolling elements: Si₃N₄ silicon nitride ceramic balls (hardness 2000 HV, centrifugal deformation only 40% of steel balls)
Cage: Polyimide TORLON (self-lubricating, heat-resistant to 260°C)
Lifespan: Clinically proven >6 months (torque loss <8% after 200 autoclave cycles)
SMR Series (Ultra-Micro Adaptive)
Representative models: SMR74ZZ, SMR84ZZ, SMR105ZZ
Size range: ID 1–5 mm (e.g., SMR74ZZ: 1.5 × 4 × 1.6 mm)
Speed: 300,000–400,000 rpm (for precision applications such as root canal treatment)
Features: Integrated flange design reduces axial vibration, noise level ≤ 68 dB.
The more you learn about bearings, the more you'll realize their ubiquity. In modern society, they've become integral to our daily lives. As a professional bearing manufacturer in China, we consistently provide customers with specialized bearing solutions. We welcome your inquiries and discussions.
