What are the main differences between YRT turntable bearings and Crossed Roller Bearings? And in what applications are they respectively suitable?

YRT turntable bearings are thrust-radial combined bearings that can simultaneously withstand axial loads, radial loads, and overturning moments, offering excellent rigidity and high rotational accuracy. They are suitable for applications requiring high rigidity and high positioning accuracy, such as CNC turntables and indexing tables. Crossed Roller Bearings use cross-arranged cylindrical rollers to withstand bidirectional axial loads and radial loads, with a compact structure, making them ideal for applications with limited space and high rotational accuracy requirements, such as industrial robot joints, harmonic reducers, and medical equipment.

How to select the appropriate bearing precision grade (P5, P4, P2) for a high-precision CNC rotary table?

P5 grade is suitable for standard CNC rotary tables and indexing mechanisms; P4 grade is designed for high-precision machining centers and grinding machine rotary tables, meeting the requirements of most precision machining applications; P2 grade represents ultra-high precision and is ideal for industries such as aerospace, optical manufacturing, and metrology instruments, where extremely tight rotational accuracy and repeatable positioning are critical. Higher precision invariably entails higher costs, so it is recommended to select the appropriate grade based on the equipment’s positioning accuracy requirements and budget constraints.

What precautions should be taken when installing thin-walled Crossed Roller Bearings?

Thin-walled Crossed Roller Bearings have relatively low rigidity, so the following points should be noted during installation: ① The mating surfaces must be highly precise to ensure that the mounting base is flat and free of burrs; ② The fastening bolts must be tightened diagonally and evenly to the specified torque to prevent deformation caused by excessive tightening on one side; ③ Before installation, check the bearing clearance or preload condition; for some models, the preload needs to be adjusted to ensure rotational flexibility and rigidity; ④ Use dedicated tooling for press-fitting, and never hammer directly.

What is the difference between bearings for harmonic reducers and ordinary Crossed Roller Bearings?

Bearings specially designed for harmonic drives—such as those in the CSF/G series—are typically required to have a smaller cross-sectional height and lighter weight to accommodate the compact structure of the reducer. At the same time, they must exhibit excellent flexibility and fatigue resistance to withstand the alternating loads and elastic deformations generated during reducer operation. Their raceway design and clearance selection are optimized for the operating conditions of harmonic drive systems.

What are the advantages of YRT bearings with an angle measurement system (YRTM series)?

The YRTM series builds upon the YRT bearing by integrating an angle encoder, enabling direct output of rotational angle position signals. This eliminates measurement errors caused by installation eccentricity and coupling backlash in conventional external encoders, thereby enhancing the turntable’s resolution and repeat positioning accuracy. It is particularly well suited for direct-drive motors (DDR) and high-precision direct-measurement applications.

How does bearing clearance (or preload) affect service performance, and how should it be selected?

Excessive clearance can lead to reduced rotational accuracy and increased vibration and noise; insufficient clearance (excessive preload) results in rapid temperature rise, inadequate lubrication, and shortened bearing life. For turntable bearings and robotic bearings, a certain level of preload (negative clearance) is typically required to enhance stiffness and eliminate backlash; the specific preload value must be calculated and determined by qualified engineers based on factors such as load, rotational speed, and fit tolerances.

What are the common lubrication methods for high-precision bearings, and how should they be maintained?

Common lubrication methods include grease lubrication and oil lubrication. High-precision bearings are typically pre-lubricated with a specialized grease before leaving the factory, and customers are advised to periodically (e.g., every 3–6 months) replenish the grease with clean lubricant. Oil lubrication is suitable for high-speed applications or situations with stringent heat-dissipation requirements; it requires an oil circulation system and regular replacement of the lubricating oil. During maintenance, ensure thorough cleaning to prevent contaminants from entering the raceways.

What could be the cause if unusual noises occur during equipment operation or if rotation becomes uneven?

Possible causes include: ① long-term operation leading to grease degradation or depletion; ② foreign objects entering the raceway, causing wear or indentations; ③ deformation of the mounting surface or loosening of the fastening bolts, resulting in bearing deformation; ④ prolonged overload or impact loading causing fatigue spalling of the raceway; ⑤ changes in the bearing’s internal clearance or preload. It is recommended to shut down the equipment for inspection and, if necessary, consult technical personnel for diagnosis.

Does your company offer custom non-standard bearing services? What is the customization process?

Yes, we can. Our company has a team of senior engineers who are capable of undertaking custom development tailored to customers’ specific requirements, including equipment space, load capacity, rotational speed, and precision. The typical process is as follows: requirements consultation (based on drawings or technical specifications) → technical solution design → customer approval → prototype fabrication → performance testing → mass production. The standard development cycle for non-standard bearings is approximately 30–60 days.

What inspections are performed on bearings before they leave the factory? How is batch consistency ensured?

Prior to shipment, each bearing set undergoes rigorous inspections for dimensional accuracy, rotational accuracy (including radial runout and axial runout), clearance, and starting torque; vibration and noise testing are also available as optional services. We have established a comprehensive quality-control system that covers the entire production process—from material receipt and heat treatment to grinding and assembly—and employ SPC statistical process control to ensure consistent performance across batch production.