The locking structure of pillow block bearings directly affects the fixing effect, operation stability and assembly convenience. At present, the mainstream locking methods on the market are divided into three types: set screw locking, eccentric collar locking and adapter sleeve locking. Different structures are suitable for different loads, rotating speeds and rotation directions, and incorrect selection is very likely to cause failures such as loosening, wear and inner ring spinning.

Set screw locking is the most common and low-cost structure. The bearing inner ring is equipped with two or more set screws, which are directly tightened against the shaft surface, enabling fast installation and simple operation. It is suitable for medium-speed, steady-load and unidirectional rotation occasions, such as small fans, short-distance conveyors and light-duty transmission mechanisms. The disadvantage is that set screws will damage the shaft surface, making it unsuitable for high-impact and frequent forward-reverse working conditions.

Eccentric collar locking holds the shaft tightly by rotating the eccentric collar, with a larger contact area and more uniform stress. Compared with set screw locking, it has better shock resistance, is not easy to loosen and causes less damage to the shaft, making it suitable for equipment with large vibration and shock loads, such as agricultural machinery, crushers, vibrating screens, mixers, etc. It can adapt to bidirectional rotation and has a longer service life, making it a common solution for heavy industrial equipment.

Adapter sleeve locking is a high-precision and high-strength locking method. It holds the shaft diameter tightly through the expansion of the adapter sleeve, featuring high coaxiality, strong clamping force and no clearance. It is suitable for high-speed, high-precision, heavy-load and frequent forward-reverse scenarios, such as machine tool accessories, high-speed fans, compressors and precision conveying systems. Although the price is slightly higher, its stability and service life are far better than the first two, making it the first choice for high-end equipment.