The four main types of bearings are ball bearings, roller bearings, plain bearings, and thrust bearings. Each type is designed to address specific load-bearing requirements and operational conditions in various machines and equipment across different industries.

   - Cylindrical Roller Bearings: Cylindrical roller bearings consist of cylindrical rollers held in place by inner and outer rings, with the rollers positioned parallel to the axis of the bearing. They are designed to primarily support radial loads and provide high rigidity and precision.

A deep groove in a ball bearing refers to the specific design feature of the bearing's inner and outer raceways, which allows it to accommodate radial and axial loads while enabling smooth and efficient rotation. The deep groove is a critical aspect of the ball bearing's construction and contributes to its performance in various applications.

Thrust Bearings: