A Guide to Bearing Noise and Vibration

What Is Bearing Acoustical Noise?

Bearing acoustical noise is the sound produced by a bearing during operation. This noise is primarily generated by the interaction of the rolling elements (balls or rollers) with the raceways inside the bearing. The friction between these moving parts creates vibrations, which, when amplified, result in sound that can vary in intensity and frequency.

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Several factors can influence the noise produced by a bearing, including:

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Bearing material:?Different materials, such as chrome steel, stainless steel, or ceramic, can affect how much noise is generated.

Raceway finish: The smoothness of the raceways inside the bearing plays a crucial role in minimizing noise. A rougher finish can increase friction and, consequently, noise.

Lubrication: The type and amount of lubricant inside the bearing can impact the noise levels by reducing friction between moving parts.

Load and speed:?Bearings subjected to higher loads or speeds often generate more noise due to increased friction.

The Importance of Noise Testing in Bearing Manufacturing

Noise testing is essential for ensuring that bearings meet the specific requirements of their intended application. Bearings used in motors, turbines, automotive parts, and other machinery must meet noise standards to avoid operational inefficiencies, premature wear, or damage to other components.

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At BYWB Bearings, the importance of noise testing cannot be overstated. As part of our commitment to providing high-quality bearings that meet stringent performance criteria, all of our bearings undergo thorough noise testing to guarantee optimal acoustic performance.

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How Bearing Noise is Tested

Noise testing in bearings is typically conducted using specialized instruments like the Anderon Meter, also known as the Anderometer, developed by Sugawara Laboratories. The Anderon Meter is widely regarded as the standard tool for measuring bearing noise, offering precise and reliable measurements across various frequency bands.

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Testing Procedure

The standard procedure for noise testing involves placing an accelerometer on the outer race of the bearing while the inner race is rotated at a constant speed, usually 1800 RPM. The accelerometer detects the vibrations generated by the bearing as it operates and categorizes the noise into three distinct frequency bands:

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High band (1,800 - 10,000 Hz): High-frequency noise produced by the interaction of the rolling elements with the raceways at higher speeds.

Medium band (300 - 1,800 Hz): Noise produced at intermediate frequencies that is typically associated with normal bearing operation.

Low band (50 - 300 Hz): Low-frequency noise resulting from the bearing’s load and speed, usually caused by larger or slower-moving rolling elements.

Each frequency band is tested separately to evaluate how much noise the bearing generates in that specific range. The noise levels are then measured and assigned a value in Anderons, the unit of measurement used for bearing noise.

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Attenuation Values

The test results are interpreted based on the attenuation settings for each bearing material and noise grade. Attenuation refers to the reduction in noise intensity at each frequency band. Depending on the material and noise grade of the bearing, different attenuation values are applied.

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For example, the following attenuation values are typically applied to bearings made from 52100 chrome steel:

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Standard: No attenuation applied.

Noise grade E: Designed to meet electric motor quietness standards.

Noise grade ER: Ultra-low noise performance, meeting spindle motor quietness standards.

BYWB's Commitment to Noise Quality

At BYWB Bearings, we understand that bearing noise is a critical consideration for many of our customers, especially those in industries that rely on high-speed motors, turbines, and sensitive machinery. That’s why we have implemented a comprehensive noise testing procedure for all our bearings, ensuring that each one meets our strict quality standards before leaving the factory.

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100% Noise Testing During Manufacturing

Unlike some bearing manufacturers that may offer noise testing as an optional service, BYWB ensures that every bearing is noise-tested during manufacturing. This guarantees that all our products meet the required noise standards for a variety of applications, from automotive and industrial machinery to precision instruments and electric motors.

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By conducting noise testing on every bearing we produce, we can offer our customers confidence in the quality of our products, knowing that each bearing has been subjected to rigorous quality control procedures.

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Noise Grades for Every Application

BYWB Bearings offers a wide range of bearings, each designed to meet specific performance criteria, including noise levels. We categorize our bearings into different noise grades to ensure they are suited to various applications:

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Standard Noise Grade: For applications where noise is not a primary concern. These bearings are tested for general use in industrial machinery and other non-precision equipment.

Noise Grade E: Specifically designed to meet the quietness standards of electric motors, these bearings produce significantly lower noise compared to standard bearings, making them ideal for applications where low noise levels are crucial.

Noise Grade ER: For ultra-low noise applications, such as spindle motors and high-speed machinery, BYWB Bearings offers Noise Grade ER bearings. These are tested to meet the strictest noise standards, ensuring minimal noise generation even in the most demanding environments.

Each of our bearings undergoes Anderon Meter testing to determine its noise performance across the high, medium, and low-frequency bands. We adhere to the < 40% full scale rule for passing the noise test, which translates to pass levels of Low < 6.4, Medium < 2.4, and High < 3.2 Anderons.

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Materials That Minimize Noise

BYWB Bearings uses only high-quality materials to manufacture its bearings, with a focus on noise reduction. Our 52100 chrome steel bearings and 440C martensitic stainless steel bearings are specifically chosen for their durability and low noise characteristics. These materials provide excellent performance in high-speed and high-load applications, while also minimizing noise levels to ensure smooth and quiet operation.

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The Impact of Bearing Noise on Performance

Bearing noise is not just a nuisance; it can also impact the overall performance and longevity of machinery. In many applications, particularly in electric motors, industrial machines, and automotive systems, excessive bearing noise can lead to:

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Increased wear: Higher friction caused by noise can lead to premature wear of bearing components.

Reduced efficiency: Noisy bearings often indicate a loss of energy, reducing the overall efficiency of the machinery.

Component damage: In some cases, excessive noise can result in damage to other components, leading to costly repairs and downtime.

By using BYWB Bearings, which undergo comprehensive noise testing, customers can reduce these risks, ensuring that their machinery operates efficiently, quietly, and reliably.

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Conclusion:

Why Choose BYWB Bearings for Noise-Optimized Performance?

At BYWB Bearings , we understand that bearing performance is about more than just load capacity and speed. Noise is an essential factor in ensuring smooth operation, and we are committed to delivering bearings that meet the highest noise standards. Whether you need standard bearings, Noise Grade E, or Noise Grade ER bearings, our products are noise-tested and carefully manufactured to provide the quietest, most efficient performance possible.

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With our state-of-the-art noise testing procedures and dedication to quality, BYWB Bearings is the trusted choice for customers looking for quiet, high-performance bearings.

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By choosing BYWB, you can be confident that your machinery will operate at its best—smoothly, quietly, and efficiently.

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