How to specify and source bearings that don’t just “fit,” but promote patient safety, procedure effectiveness and device reliability.
Engineering precision is an art of nuance — especially when it comes to selecting the right bearing for medical devices. What begins as a straightforward specification process quickly becomes a complex yet familiar puzzle of competing requirements. Oftentimes, engineers discover that a bearing’s performance extends beyond its basic dimensional specs, involving considerations of material properties, system integration and supply chain dynamics.
The consequences of bearing choice can ripple through design, manufacturing and ultimately, device performance. A seemingly minor technical oversight can compromise device reliability, increase production costs or introduce unexpected failure modes. In medical device engineering, these aren’t just technical challenges — they’re critical decisions that can directly impact clinical outcomes.
Most engineers initially approach bearing selection through a lens of technical specifications like internal and external diameters, load-bearing capacities and force calculations: either a bearing fits or it doesn’t. Either a bearing can handle the required forces or it can’t. Yet these metrics tell only part of the story.
This article delves into some of the design engineering and supply chain issues for medical device bearings, providing insights into their implications. It also offers guidance on how to optimize the bearing selection process with your supplier, ensuring your components perform reliably.
Your supplier can help you understand the specific needs of the bearing in a way that avoids costly over- specification. Part of this process involves the material selection. Bearings made from ceramic or stainless steel, for example, provide the necessary corrosion resistance and compatibility with sterilization processes, ensuring the bearings perform optimally without unnecessary, costly enhancements.
Navigating Bearing Selection With Your Supplier
At Boca Bearings, we understand that selecting the optimal bearing for a medical device is a critical decision with far-reaching implications. With decades of technical experience and a deep understanding of the stringent requirements of the medical industry, we partner with engineers to navigate the complexities of bearing specification. Our goal is always to recommend and supply the bearing that provides the ideal balance of performance, reliability and cost-effectiveness for your specific application.
Partnering with an experienced bearing supplier like Boca Bearings is crucial for successful medical device design. It’s also important to work with a supplier that emphasizes the integration of bearings into the overall medical device design. These suppliers collaborate closely with device manufacturers to ensure the components aren’t considered in isolation, leading to better device performance.
Instead of reaching for the most complex or costly solution, the best bearing suppliers focus on precise optimization, treating each medical device as a unique engineering challenge. In some cases, the ideal bearing solution requires a custom component that transcends what standard off-the-shelf bearings can offer. In practice, this means going beyond simple dimensional matching and understanding how features like bearing stiffness, radial loads and axial play affect the device’s mechanical ecosystem.
For example, an application involving a molecular diagnostic testing system required modified versions of standard bearings from Boca Bearings. Engineers implemented specific design modifications, including specialized corner breaks and lubrication systems, ensuring these components were optimized for the diagnostic equipment. The bearings play an important role in this point-of-care platform, which delivers fast, accurate PCR results — the gold standard for diagnostics in hospitals, laboratories and near-patient settings.
In another application, Boca Bearing engineers carefully selected units with specific clearance levels and specialized lubrication that met performance requirements for a breast biopsy tool. The end-user had been using bearings with MC3 clearance yet required components with MC5 clearance. Boca Bearings sourced its stainless steel bearings with MC5 clearance, along with ABEC#5/ISOP5 ratings and AF2 lubricant.
Driving Cost and Complexity With Over-Engineering
Engineers face two primary challenges when selecting bearings for medical equipment: over- engineering and failure to consider bearings as part of an integrated system.
Over-engineering occurs when designers select bearings with specifications that exceed the actual requirements of the medical device. For example, a designer may choose a bearing with unnecessarily high precision levels, excessive load capacities or advanced materials. While this approach may seem harmless at first, it can significantly increase cost without contributing to the device’s performance in any meaningful way. Our role as your bearing partner is to help you identify the appropriate level of precision and specifications needed for your device to function optimally and reliably, avoiding unnecessary expense.
Here are a few common scenarios.
Precision levels. Many engineers select bearings with very high Annular Bearing Engineers’ Committee (ABEC) ratings, selecting units with precision levels that far exceed the medical device’s actual operational needs. While highly precise bearings reduce wear and improve performance in extreme conditions, they are not always required. An imaging device or laboratory centrifuge, for example, rarely requires the same precision as a high-speed aerospace system.
Load capacities. While it may seem prudent to select bearings with load capacities that exceed an application’s requirements, this approach can lead to increased costs without any tangible benefits in terms of device performance or lifespan.
Material selection. Specialized polymers and other advanced materials may be beneficial in certain applications, but they may be overkill in others. Again, this approach not only increases the material costs but can also complicate the manufacturing process. In addition to driving costs, the consequences of bearing over-engineering extends to the supply chain. Bearings with high precision and load specifications, for example, may not be readily available in large quantities, leading to manufacturing delays and longer lead times. This is especially the case for medical devices that don’t have high production volumes.
Bearings as Part of an Integrated System
A second pitfall many engineers and designers face involves treating bearings like standalone components, which can lead to design and performance challenges that compromise device functionality. Rather, it’s important to remember that bearings are important elements of complex mechanical systems.
Failure to consider this integration can cause the following issues:
Tolerance stack-up. One possible effect of considering bearings in isolation is tolerance stack-up, where the cumulative effect of individual component tolerances can lead to misalignment, poor mechanical fit and reduced device reliability. In medical imaging devices, for example, even minor misalignments can compromise image quality.
Assembly issues. Bearings designed without considering the entire manufacturing process can cause downstream complications, increasing assembly time, raising the defect rates and even compromising device integrity.
Performance degradation. Bearings that don’t integrate well with other components in the assembly can erode device performance, causing increased friction, noise and wear, for example. These issues can reduce the lifespan of the device and drive maintenance, which can cost the company significantly in engineering maintenance and machine downtime. A medical imaging machine down for a few hours can impact revenue by $100,000.
In medical equipment, these implications carry particularly high stakes, as device performance and reliability directly impact patient safety and treatment efficacy. By working closely with your design team, we help ensure the selected bearings integrate seamlessly into the overall system, minimizing tolerance issues, facilitating efficient and reliable production, preventing performance degradation and ensuring long-term device reliability.
The Importance of Quality Control
Throughout the bearing selection process, quality control is paramount. This process involves rigorous component testing, verification of medical-grade standards and detailed specification reviews. In addition to technical know-how, bearing suppliers should be certified to ISO 9001 — a global benchmark for quality management. This certification demonstrates a commitment to quality control standards and ensures the bearings consistently meet regulatory requirements.
The Medical Device Development Cycle
It’s worth noting that bearing selection extends beyond just engineering challenges and involves the complexities of medical device development cycles. Unlike other industries, medical devices often progress through extended development phases — from the prototype phase, which requires small quantities, to test production, which involves medium quantities, to full-scale production.
This cycle creates unique challenges in component sourcing and consistency. Suppliers like Boca Bearings are well-positioned to support customers throughout this entire journey, offering design engineering during initial phases, small-quantity prototyping capabilities during development, and the logistics and quality control systems necessary for full overseas production. This end-to-end support ensures component reliability and performance throughout the medical device’s lifecycle.
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Selecting the right bearings for medical devices requires a holistic approach that transcends basic dimensional specifications and load calculations. Successful engineers recognize that over-engineering and failure to consider bearings as part of an integrated system can drive unnecessary costs and time without performance benefits.
True bearing expertise is rare in today’s market, yet critical for medical device success. A trusted and knowledgeable bearing partner is invaluable throughout the entire development process — from initial part identification and engineering consultation, to the transition from prototyping to full-scale production.
At Boca Bearings, we’ve demonstrated this expertise across many medical applications and have developed specialized solutions for molecular diagnostic systems, surgical robotics, biopsy tools and more. Unlike typical component vendors, experts like Boca Bearings serve as engineering partners who understand the complete medical device ecosystem, recommending optimal precision ratings, clearance specifications and material choices in ways that enhance device effectiveness and reliability.
When your medical device demands the highest levels of performance, reliability and patient safety, partnering with bearing specialists becomes not just advantageous — but essential to success.
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