Why Use A Bushing Instead Of A Bearing ?

Differences from the perspective of core functions
Both bushings and bearings serve to support and reduce friction, but the core design logic is different:
• Bushing: It is a single sliding friction component with a simple structure, equivalent to a "wear-resistant sleeve", relying on its own material or lubricating medium (oil/grease) to reduce friction, mainly bearing radial loads, and partially bearing lightweight axial loads.
• Bearings: They are divided into sliding bearings and rolling bearings. Rolling bearings achieve rolling friction through rolling elements (steel balls/rollers), with a lower coefficient of friction and the ability to withstand larger loads and higher speeds. Some types can withstand both radial and axial loads simultaneously.

The core scenario of choosing bushings instead of bearings
1. Low cost and lightweight requirements
The bushing structure is simple, and the materials are mostly bronze, nylon, graphite, etc. The cost per piece is much lower than that of rolling bearings; And without the need for supporting components such as bearing seats, it can significantly reduce the overall weight, making it suitable for cost and weight sensitive scenarios such as small agricultural machinery, toys, and simple conveying equipment.
2. Adaptability to harsh working conditions
• Dust/sediment environment: For example, the bucket pin shaft of construction machinery, the suspension components of agricultural machinery, and the rolling elements of rolling bearings are easily stuck by impurities, while the sliding friction surface of the bushing can "contain" impurities to a certain extent, making it less prone to failure.
• Heavy load and low speed scenarios: such as the crane's leg shaft and the memorial archway bushing of the steel rolling machine, the rolling element of the rolling bearing is prone to pitting under low speed and heavy load, while the large area contact of the bushing can evenly distribute the load and has a longer service life.
3. Limited installation space
The bushing can be made into a thin-walled structure, or even directly embedded into the part body (such as sintering bronze bushing in the inner hole of cast iron parts), without the need for additional bearing installation space, suitable for compact design equipment such as valve guides for automotive engines and fine adjustment mechanisms for precision instruments.
4. Maintain convenience
After the bushing is damaged, it is usually only necessary to press out the old bushing and press in the new bushing to complete the replacement, without the need for professional tools; When replacing rolling bearings, precise adjustment of clearance and installation of seals are required, making maintenance more difficult and costly, and suitable for remote areas or scenarios without professional maintenance personnel.

Not suitable for scenarios where bushings are used to replace bearings
• High speed applications (such as motor spindles and machine tool spindles): The sliding friction of the bushing generates a large amount of heat, leading to increased wear, and the rolling friction of rolling bearings is more suitable.
• Scenarios with extremely high precision requirements (such as precision machine tools and robot joints): The clearance between bushings is difficult to achieve micrometer level precision of rolling bearings, which can easily cause shaking and affect accuracy.