Double row deep groove ball bearing is a rolling bearing designed with deep groove raceway, and its standard models include 4200A and 4300A. Compared with single row deep groove ball bearings, when the outer diameter and inner diameter are the same, the axial width is larger and the radial load-bearing capacity is significantly higher, which is suitable for scenarios where single row bearings cannot meet the load-bearing requirements 1. The following are its main features and application information: structural characteristics No ball gap design: The raceway has a high degree of fit with the steel ball, and can withstand both radial and bidirectional axial loads simultaneously. Holder: The standard model is equipped with a glass fiber reinforced nylon 66 holder (suffix TN9) guided by two steel balls, and the working temperature needs to be controlled below 120 ℃ Sealing: Only available in an open structure, without seals or dust covers. Some models come with stop slots to simplify installation Application precautions Alignment error: The axis hole alignment error is allowed to not exceed 2 arc minutes, otherwise it will result in additional load and shortened service life Minimum load: It is necessary to ensure a minimum radial load, especially under high-speed or high acceleration conditions, to avoid sliding between the steel ball and the raceway Axial load limit: The pure axial load shall not exceed 0.5 times the rated static load (Co), otherwise it will significantly reduce the service life