Quality Precision Ball Bearings & Angular Contact Ball Bearings Manufacturer

Precision, reliability, and long life in machine tool spindles don’t happen by accident. One of the most important—but often overlooked—factors is bearing preload. Preload is the controlled axial force applied to bearings during spindle assembly. It’s not just a step in installation—it’s a key design decision that directly affects how your spindle performs every day. What Does Proper Preload Do? When done right, bearing preload delivers real-world benefits: 1.Higher Rigidity = Better Accuracy Preload removes internal clearance, so the bearing resists deflection under cutting forces. This means your spindle stays stable during heavy cuts—resulting in tighter tolerances and smoother surface finishes. 2.Less Runout, Less Vibration With no play between components, rotational accuracy improves. Axial and radial runout drop, reducing chatter and vibration—critical for fine-detail machining. 3.Longer Bearing Life Even load distribution prevents stress hotspots. Plus, preload reduces skidding (micro-slippage) of rolling elements—especially at startup or high speeds—cutting down on wear and early failure. 4.Quieter, Smoother Operation A well-preloaded bearing runs smoothly without the clunk or noise caused by parts moving in and out of clearance zones. Quiet operation often signals a healthy spindle. 5.Stable Performance Under Heat During high-speed runs, metal parts expand. Proper preload compensates for thermal growth, keeping bearings securely seated and preventing loss of precision. How to Apply Preload the Right Way Getting preload right isn’t guesswork. Here’s what matters: Choose the Right Amount Too little? Your spindle lacks stiffness. Too much? Bearings overheat and fail fast. The ideal preload is usually 10–30% of the bearing’s original radial clearance, adjusted for your specific speed, load, and temperature conditions. When in doubt, consult a bearing specialist. Pick the Best Method for Your Application 1.Fixed (Position) Preload: Uses precision-ground spacers. Best for medium-speed, high-load spindles where maximum rigidity is needed. 2.Spring (Constant Pressure) Preload: Uses disc or coil springs. Ideal for high-speed spindles—it automatically adjusts for thermal expansion and wear, avoiding dangerous over-preload. Account for Heat in Real Operation In high-precision machines, temperature changes affect preload. Advanced spindles may include sensors and active systems to maintain optimal preload during operation—keeping accuracy consistent from first cut to last. Final Thought: Preload Is Part of the System Great spindle performance comes from more than just high-quality bearings—it comes from how they’re installed and tuned. For angular contact ball bearings (often used in matched pairs), preload is especially critical. At Beining Technology, we design and manufacture precision spindle bearings used in CNC machines worldwide. But we also share deep application knowledge—because the best bearing only delivers its full potential when paired with the right engineering support. Need help choosing the right preload strategy for your spindle? Contact our engineering team—we’ll help you get the accuracy, life, and reliability your machine deserves.    

The spindle is the heart of any CNC machine, spinning at high speeds with extreme precision. At its core are the spindle bearings, critical rotating components that endure heavy loads, heat, and stress. Over time, they wear out, leading to noise, vibration, or overheating. Replacing them correctly is essential to restore accuracy, performance, and longevity. Here is a step-by-step guide to do it right. Step 1: Remove the Spindle Housing Use appropriate tools such as screwdrivers or wrenches to remove protective covers. Carefully extract the entire spindle assembly—use a hoist if necessary. Avoid any impacts or drops, as even minor shocks can damage internal components. Step 2: Remove the Old Bearings Use a bearing puller clamped onto the inner ring to apply even force during removal. For tight-fit bearings, heat the spindle housing evenly to 50–80°C using an induction heater. This thermal expansion makes removal easier and safer. Step 3: Inspect and Clean Thoroughly Clean the bearing seat and spindle shaft with a lint-free cloth and approved solvent. Check for scratches, dents, or corrosion on all mating surfaces. If damage is found, repair or replace the spindle shaft—imperfect surfaces will compromise the performance of new bearings. Step 4: Heat the New Bearing Heat the replacement bearing evenly to 80–100°C using a bearing heater or clean oil bath. This causes the inner ring to expand slightly, allowing for a smooth, interference-free fit. Step 5: Install and Apply Preload Quickly slide the heated bearing onto the shaft. Use a proper installation sleeve to apply steady, even pressure—never strike the bearing directly with a hammer. Apply the correct preload based on your application: fixed-position preload is ideal for stable high-speed operation, while constant-pressure preload works better under varying speeds or temperatures. Always follow the OEM or bearing manufacturer’s specifications. Step 6: Lubricate Properly Select grease or oil according to the spindle’s requirements. For grease, fill only 30% to 40% of the bearing’s free space—over-packing causes churning and excessive heat. For oil-air or oil-mist systems, strictly follow the manufacturer’s guidelines for flow rate and lubrication intervals. How to Verify Correct Installation A proper installation ensures long service life and optimal performance. Confirm success with these checks: Manual Rotation Test Rotate the spindle by hand. It should turn smoothly and quietly, with no grinding, catching, or resistance. Low-to-High Speed Run-In Start the spindle at low speed, then gradually increase to normal operating speed. Listen for unusual noises and monitor for excessive vibration. Temperature Check After running for about four hours, the outer ring of the bearing should not exceed ambient temperature by more than 35°C. Use a thermal camera if available—temperature variation across the same bearing should be less than 5°C. Final Cutting Test Perform a test cut on a sample workpiece under standard conditions. A good surface finish and accurate dimensions confirm that the bearing has been installed correctly. Why Precision Matters Spindles often operate at thousands—or even tens of thousands—of RPM. Even slight misalignment or incorrect preload can cause excess friction, rapid heat buildup, premature failure, and loss of machining accuracy. A rushed replacement may save minutes but cost hours in downtime and scrapped parts. About Beining Technology Beining Technology specializes in manufacturing high-precision spindle bearings for demanding CNC and machine tool applications. Our bearings are engineered for reliability, high-speed stability, and micron-level accuracy—trusted by manufacturers who refuse to compromise on performance.

Cross roller bearings handle radial loads, axial loads, and tilting moments all at once. They are compact and precise—commonly used in robot joints, rotary tables, medical devices, and automation equipment. Picking the wrong one can hurt performance and shorten machine life. Here is what really matters when selecting one. 1.Know Your Application First Different machines need different bearings. Robot arms need high rigidity, low friction, and small size. Rotary tables require high rotation accuracy and repeatability. Medical or lab equipment must run quietly and stay clean. Be clear about your use case—it drives every other decision. 2.Check Available Space Measure these three dimensions: shaft diameter (inner ring size), housing bore (outer ring size), and mounting height (bearing thickness). If space is tight, look for thin-section cross roller bearings like RU, XRT, or CRBH series. They save room without losing stiffness. 3.Understand Your Loads Cross roller bearings carry three types of force: radial load (side force, perpendicular to shaft), axial load (thrust along the shaft), and moment load (tilting or overturning force). Check the manufacturer’s load rating chart. Keep your actual load below 80 percent of the rated capacity for safety and long life. 4.Do Not Over-Specify Precision Common accuracy grades are P5, P4, and P2 (lower number means higher precision). For general automation, P5 is usually enough. For high-end robots or CNC turntables, go for P4 or better. Higher precision costs more—but if your machine does not need it, you are just wasting money. 5.Price Is Not Everything Cheap bearings often cut corners. Poor steel wears out fast. Inconsistent grinding causes uneven rotation. Wrong preload leads to low rigidity or noise. Look for suppliers who offer stable quality, test reports (runout, preload, etc.), and real technical support. A reliable bearing saves downtime and maintenance later.   Why Choose Beining Technology? We design and manufacture cross roller bearings for demanding applications like hollow rotary platforms, robotic joint modules, and precision indexing tables. Our advantages: 1.Standard models in stock (RU, XRB, SHF, CRBH series) 2.Custom sizes, preload, and sealing available 3.Every batch tested – reports provided 4.Engineers ready to help with selection