How can you tell whether a crossed roller bearing is good or bad? And how do you select the right model correctly?

Crossed roller bearings, with their advantages of high rotational accuracy, ease of installation, and compact design that saves installation space, are widely used in various machine tools, robotic joints, medical devices, and other fields—areas that have stringent requirements for bearing quality. So, how can we distinguish between good and bad crossed roller bearings during the selection process? Below, our Ovite editor will introduce you to methods for assessing bearing quality.

I. Methods for Assessing the Quality of Crossed Roller Bearings

1. Packaging: Regarding the outer packaging of bearings, normally, reputable bearing companies—especially those with their own brands—will feature their company’s brand logo on the packaging. Additionally, they will use packaging specifically designed for their products and will have the packaging manufactured by factories that meet stringent production standards. As a result, the packaging exhibits exceptionally clear lines and color blocks, and prominently displays the company’s logo.

2. Examine the stamped markings on the bearing: Typically, bearings will have the name and logo of their brand, along with model numbers and other identifying information printed on them. The lettering is exceptionally clear, usually applied using a steel-stamping technique—imprinted before the bearing undergoes heat treatment. As a result, although the font is small, the impressions are deep and remarkably sharp. In contrast, counterfeit products of poor quality often feature blurry lettering that easily wears off or peels away.

3. Listen for any unusual noises: Hold the bearing in your left hand, gripping the inner race, and use your right hand to gently spin the outer race. Listen carefully for any extraneous sounds. Since most counterfeit products are manufactured under outdated conditions—often through entirely manual, workshop-style operations—it’s inevitable that impurities such as sand will get mixed into the production process, causing unwanted noises when the bearing is rotated. In contrast, high-quality bearings won’t produce such noises, because even small amounts of impurities can compromise the bearing’s proper function.

4. Check whether there’s a lot of oil residue: High-quality bearings, even after undergoing rust-prevention treatments—whether using rust-inhibiting oil or other methods—will not show much residual oil stain. The bearings will still appear bright and shiny. In contrast, poorly treated bearings may feel oily to the touch when you run your fingers over them.

5. Inspect the chamfering: Check whether the chamfering is evenly processed. The chamfer refers to the junction between the horizontal and vertical surfaces. In high-quality bearings, the chamfered edges are perfectly uniform. However, some counterfeit bearings, due to immature manufacturing techniques, often exhibit incomplete or uneven processing at these edges and corners.

Now that we’ve learned how to distinguish between good and bad crossed roller bearings, let’s go on to explore some key considerations for selecting crossed roller bearings—helping us choose the right bearing products for our needs.

II. Key Considerations for Selecting Crossed Roller Bearings

1. Dimension Range: The external dimensions are an important parameter. First, you need to determine the size of bearing you require—in other words, you must know the installation dimensions of the equipment where this bearing will be installed—before you can select the appropriate bearing size.

2. Structural Types: Depending on the same outer dimensions, cross roller bearings come in various structural designs. There are those with a split outer ring (XRB/XRA), those with a split inner ring (XRE), and those with an integral structure (XRU/XRBH). The key factor is whether the part to be driven by rotation needs to be mounted on the inner ring or the outer ring of the bearing. If the outer ring needs to rotate, a bearing with a split inner ring must be used. Similarly, if high rotational accuracy is required for the inner ring, a bearing with a split outer ring must be selected. When both the inner and outer rings need to achieve high rotational accuracy, an integral structure bearing—where both rings are integrated into one unit—is the most suitable choice.

3. Installation Method: From the perspective of installation method, cross roller bearings can be broadly categorized into two types. One type features mounting holes on both the inner and outer rings—similar to slewing bearings—making installation relatively straightforward; they can be directly bolted onto the equipment. The other type has neither the inner nor outer ring equipped with mounting holes, and relies primarily on a bearing housing, a compression flange, and an interference fit between the shaft and the inner diameter of the bearing.

4. Load Capacity: When selecting a cross roller bearing, it is essential to determine whether it can withstand the load imposed by the equipment. The suitability should be assessed based on the equipment’s design load requirements and the rated load capacity of the corresponding bearing.

5. Precision and Clearance: The precision and clearance of cross roller bearings are central to their performance. The bearing’s clearance can affect factors such as the rigidity, noise level, service life, and rotational speed of the cross rollers.

The above is an introduction to how to distinguish between good and bad cross roller bearings and how to select the right model. We hope this information will be helpful to you. In addition, our Aowei Bearing company has extensive experience in the production of cross roller bearings. If you have any needs, feel free to give us a call for more information.