Cases

Applications of Newbee Thin-section Bearings in the Medical Field: Non-Magnetic Precision Transmission Solutions

In MRI (Magnetic Resonance Imaging) equipment, thin-section ball bearings serve as the core components of the scanning gantry and gradient coil rotation mechanisms. Their performance directly determines the image resolution and equipment reliability. The strong magnetic field, ultra-clean requirements, and long-term continuous operation characteristics of the MRI environment pose extreme challenges to the bearing materials, structural design, and manufacturing processes. This article combines the technical accumulation of Luoyang Newbee Precision Bearings in the semiconductor field to deeply analyze the innovative solutions for MRI-specific thin-section bearings.

Special Challenges of MRI Equipment for Thin-section Bearings 

(I) Three Core Technical Barriers

1.Requirements for Non-Magnetic Compatibility-Risks of Strong Magnetic Field Interference: The magnetic field strength of MRI equipment is usually 1.5T-3T. Traditional ferritic stainless steels containing iron (such as 440C) will be magnetized, which can disrupt the magnetic field uniformity and cause image artifacts (diagnosis fails when the artifact rate is > 5%).-Material Selection Constraints: Austenitic stainless steels (such as 316L with a magnetic permeability ≤ 1.001μ₀) or all-ceramic materials must be used, while also meeting the bearing strength (hardness ≥ HRC58) and wear resistance requirements. Ultra-Clean and Corrosion-Resistant Environment-Consequences of Particle Contamination: Metal particles (≥ 5μm) generated by bearing wear will interfere with the magnetic field gradient, resulting in a layer thickness error > 0.3mm and a decrease in image resolution by more than 50%.-Erosion by Disinfectants: MRI equipment commonly uses alcohol and peracetic acid for disinfection. The coatings of traditional bearings are easily corroded, leading to peeling or rusting (with an occurrence rate of approximately 12% per year).

2. High-Precision Rotational Stability-Vibration Control Requirements: When the scanning gantry rotates at 150-200rpm, the radial runout of the bearing needs to be ≤ ±1μm. Otherwise, it will cause blurring of the tomographic image (the layer thickness accuracy deteriorates from 0.15mm to 0.5mm).

3.Low-Temperature Adaptability: The operating temperature of some superconducting MRI equipment can be as low as -20°C. The thermal expansion coefficient of the bearing material needs to be ≤ 12ppm/°C to avoid accuracy drift caused by changes in the clearance due to temperature differences.

 Newbee's MRI-Specific Thin-section Bearing Solutions:

Full-Link Innovation from Materials to Systems

 Material Technology: Dual Certification of Non-Magnetic and Biocompatibility

<!--[if !supportLists]-->1. <!--[endif]-->Innovation of Main Materials-Medical-Grade 316L Stainless Steel: Complies with the ASTM F138 standard, with a carbon content ≤ 0.03%. It is non-magnetic and resistant to body fluid corrosion. It has passed the 3T magnetic field environment test (the image artifact rate caused by magnetic interference = 0%).-Ceramic Hybrid Bearings: Use silicon nitride (Si₃N₄) ceramic balls (with a density of 3.2g/cm³, only 60% of that of steel balls) paired with 316L stainless steel raceways. The weight is reduced by 40%, and at the same time, non-magnetic characteristics are achieved (residual magnetism < 0.1mT).

<!--[if !supportLists]-->2. <!--[endif]-->Upgrading of Surface Treatment Technology

DLC Diamond-Like Carbon Coating: With a thickness of 8-10μm, the friction coefficient is reduced to 0.05 (0.18 for traditional bearings), the wear-resistant life is increased by 15 times, and particle generation is effectively reduced (the pollution rate is 0.01mg/m³, 98% lower than the industry average).-Parylene Coating: A nanoscale film (2-5μm) that isolates the erosion of disinfectants. It has passed the 72-hour salt spray test (NSS standard) with no corrosion spots on the surface.

 Structural Design

Precision Enhancement and Environmental Adaptation

1.Optimization of the Four-Point Contact Ball Structure-Bidirectional Load Balance: The axial stiffness is increased by 20%, effectively counteracting the centrifugal force during the rotation of the gantry (the radial load reaches 4kN at 200rpm) and ensuring that the vibration displacement is ≤ ±1μm.

2.Thin-section Design: The cross-section height is ≤ 8mm, which is suitable for the compact space of the MRI gantry. At the same time, the radial load-carrying capacity is maintained at ≥ 5kN (15% higher than that of traditional bearings).

3.Intelligent Lubrication and Sealing System-Laser-Etched Micro-Oil Storage Grooves: Spiral grooves with a depth of 0.1mm are processed on the raceway surface to store food-grade lubricating grease (complying with the NSF H1 standard), achieving 20,000 hours of maintenance-free operation (the maintenance cycle of traditional bearings is only 2,000 hours).-Magnetic Fluid Seals: Non-magnetic rubber seals are used in combination with a labyrinth structure to prevent external particles (≥ 0.5μm) from entering and can withstand a temperature range of -40°C to +80°C.

 Manufacturing Process

Micron-Level Precision Control System

<!--[if !supportLists]-->1. <!--[endif]-->Vacuum Heat Treatment Process-Solution treatment is carried out in a vacuum environment of 10⁻³ Pa to eliminate internal stresses in the material. The roundness error of the raceway is controlled within ±0.5μm, and the cylindricity error is ≤ 1μm, ensuring that the radial runout during rotation is ≤ ±1μm.

<!--[if !supportLists]-->2. <!--[endif]-->Cleanroom Assembly Process-Assembly is completed in an ISO Class 5 cleanroom (with a particle concentration of ≥ 0.5μm ≤ 35,200 particles/m³). Deionized water is used for cleaning (with a conductivity ≤ 1μS/cm). Finally, the bearing cleanliness reaches NAS Class 5 (with a particle count ≤ 100 particles/ft³), far exceeding the requirements of MRI equipment.

 Typical Application Scenarios and Performance Verification

(I) Applications of Core Components in MRI Equipment

 (II) Comparison of Laboratory Test and Clinical Data

1. Key Performance Indicators-Magnetic Field Compatibility: When continuously operating in a 3T MRI device for 24 hours, the image layer thickness deviation is ≤ 0.05mm (the deviation of traditional bearings is ≥ 0.3mm), meeting the AAPM TG-100 standard.-Life Test: Under a 100N radial load + 50N axial load, 10 million cycle tests were completed, and the wear amount was only 2μm (the wear of traditional bearings is ≥ 15μm), meeting the 10-year design life of MRI equipment.-Cleanliness Certification: Passed the NASA-standard cleanliness test (ASTM E1241), with particle emissions reduced by 98% compared to traditional bearings, meeting the Class 1 cleanroom requirements.

2. 

 Customer Case:

Renovation of a 3.0T MRI Device in a Class-A Tertiary Hospital-Pain Points: The original bearings caused blurred images due to magnetic interference every 18 months, requiring downtime for maintenance, with a single loss of ¥30,000. The peeling of the coating after disinfection posed a risk of bacterial growth.-Solutions: NBT-80MRI thin-section bearings (316L stainless steel + Parylene coating) were used, integrated with vibration sensors.-Results: The device has been operating without failure for 36 months. The image resolution has been improved from 0.3mm to 0.15mm. The integrity retention rate of the coating after disinfection is 100%, and no colonies were detected in the bacterial culture test.

 Industry Trends and Newbee's Core Advantages

<!--[if !supportLists]-->(I) <!--[endif]-->Development Trends of MRI Bearing Technology

<!--[if !supportLists]-->1. <!--[endif]-->Adaptation to Ultra-High Field Strengths: 7T and above ultra-high field MRI equipment requires bearings with a magnetic permeability ≤ 1.0005μ₀, promoting the application of all-ceramic bearings (such as zirconia materials).

<!--[if !supportLists]-->2. <!--[endif]-->Integration of Intelligent Monitoring: Built-in temperature/vibration sensors can transmit data in real-time through the IoT to achieve predictive maintenance (such as automatic early warning when the clearance increases > 10μm).

<!--[if !supportLists]-->3. <!--[endif]-->Lightweight Design: The demand for mobile MRI equipment (such as vehicle-mounted MRI) is increasing, driving the cross-section height of bearings to evolve towards ≤ 6mm while maintaining a radial load-carrying capacity of ≥ 3kN.

Three Core Advantages of Choosing Newbee

<!--[if !supportLists]-->1. <!--[endif]-->Full-Process Magnetic Compatibility Verification-Equipped with a 3T magnetic field test platform, each batch of bearings passes the magnetic interference simulation test to ensure an image artifact rate of 0%.-Material certifications cover USP Class VI biocompatibility and EU MDR medical device directives, meeting the access requirements of global high-end medical equipment.

<!--[if !supportLists]-->2. <!--[endif]-->Customization and Quick Response Capabilities-A full range of inner diameters from 15-120mm is available, and non-standard sizes can be prototyped within 72 hours (such as special specifications suitable for MRI gantries of brands like GE and Siemens).-Flexible coating options: DLC (wear-resistant), Parylene (corrosion-resistant), silver-ion (antibacterial), etc., are suitable for different disinfection scenarios.

<!--[if !supportLists]-->3. <!--[endif]-->Failure Analysis and Continuous Improvement-The professional laboratory is equipped with SEM scanning electron microscopes and EDS spectrometers to locate the root causes of failures (such as lubrication failure and material fatigue) within 72 hours.-Based on the R & D experience of over 200 semiconductor bearings, nanoscale surface treatment technology has been transferred to the medical field, achieving cross-industry technology reuse.

The high-precision imaging requirements of MRI equipment have promoted the upgrade of thin-section bearings from "components" to "system-level solutions". Relying on semiconductor-grade manufacturing processes, Luoyang Newbee Precision Bearings has broken through the three bottlenecks of non-magnetic materials, cleanliness, and precision control, providing a reliable transmission core for 3.0T/7T MRI equipment. We not only provide bearing products but also contribute to improving the accuracy of medical imaging diagnosis and the stability of equipment operation through material innovation, intelligent monitoring, and full-life cycle services, contributing "bearing power" to the localization of high-end medical equipment.