Principle of Office Chair Bearings

The principle of office chair bearings mainly relies on the bearing structure of the chassis to achieve smooth rotation, completing power transmission and direction conversion by reducing friction.

1. Common Bearing Structure Designs

1. Integrated Chassis Bearing Structure
   This design embeds ball bearings or sliding friction bearings beneath the chassis, securing the seat and five-star base through a central rotating connector. During rotation, the seat drives the internal bearings to rotate around the central axis, while the five-star base remains stationary to support the ground. Its core power transmission path relies on the meshing of the bevel gear at the end of the central shaft with the wheel frame gear, converting vertical axial rotation into horizontal rolling. The application of precision ball bearings reduces the friction coefficient to below 0.01, significantly improving energy conversion efficiency.

2. Split Rotating Disk Structure
   High-end office chairs often adopt an independent rotating tray installed between the base and the five-star base. The tray is equipped with wear-resistant nylon pads or steel balls on the top and bottom, achieving rotation through pad sliding during rotation. Compared to the integrated structure, the split design offers stronger load-bearing capacity, can accommodate larger chair bodies, and is particularly suitable for scenarios requiring frequent angle adjustments.

2. Key Components and Material Characteristics

• Central Shaft: Made of 42CrMo alloy steel, it achieves a hardness of HRC28-32 after quenching and tempering, combining high strength and fatigue resistance to ensure no deformation during long-term use.
• Wheel Frame: Uses PA66+30%GF engineering plastic, enhanced with glass fibers to improve strength while providing shock absorption performance, reducing vibration and noise during rotation.
• Roller Bearings: Equipped with 6200 series sealed bearings internally, preventing dust intrusion through sealed design and passing 80,000 rotation tests without abnormalities, ensuring service life.
• Friction Types: Rolling bearings rely on steel balls or rollers to convert sliding friction into rolling friction, resulting in a lower friction coefficient; sliding bearings reduce friction through an oil film between the shaft and sleeve, requiring regular lubricant supplementation to maintain performance.

3. Maintenance and Troubleshooting

If the bearings experience stuttering or abnormal noises, it is usually caused by dust intrusion or insufficient lubrication. Maintenance steps are as follows:

1. Remove the base and wipe the bearing surface dust with a soft cloth;
2. Apply a small amount of sewing machine oil or special grease to the bearing raceway;
3. Reassemble and test the rotation smoothness.
   Regular maintenance (recommended every 6 months) can significantly extend bearing life and avoid component wear caused by dry friction. Additionally, avoiding use in humid or corrosive environments can prevent metal parts from rusting and affecting performance.