Internal Structure of Office Chair Base

The internal structure of an office chair base primarily consists of components such as a metal frame, rotating shaft, springs, dampers, and incorporates a control mechanism to achieve functions like rotation, backrest adjustment, and load-bearing connection.

Internal Structural Composition

The core frame of the base is a metal frame, typically made of high-strength steel or aluminum alloy to ensure overall structural stability. A rotating shaft is installed on the frame, serving as the axis for the horizontal rotation of the seat, supporting the free rotation of the seat around the axis of the gas lift. Springs and dampers are key components for adjusting the backrest function: the springs provide rebound force, while the dampers control the speed of the backrest tilt to prevent sudden drops; some high-end bases use fiberglass springs instead of traditional springs to achieve more precise force feedback through material deformation. The control mechanism is divided into two parts: a right-side control lever controls the lifting and backrest locking through mechanical linkage, and a bottom cylindrical knob is used to adjust the backrest rebound force, allowing users to adjust the resistance according to their weight or usage habits.

Core Function Implementation

1. Horizontal Rotation: The cooperation between the rotating shaft and the metal frame enables the seat to rotate 360 degrees, enhancing flexibility in office scenarios, such as turning around to pick up items or communicate with colleagues without moving the entire chair.
2. Backrest Adjustment: By operating the control lever, the mechanical structure inside the base (such as springs or fiberglass springs) can lock the backrest tilt angle to meet different posture needs, such as sitting upright, slightly reclining, or semi-lying down; adjusting the rebound force with the knob ensures that users of different weights can obtain a comfortable rebound experience. High-end bases adopt a synchronous tilt mechanism, where the backrest and seat cushion move in tandem during recline, maintaining waist and back alignment and avoiding the issue of a "hollow waist" found in traditional bases.
3. Load-Bearing and Connection: The upper end of the base is fixed to the seat cushion frame with bolts, directly bearing the user's weight; the central hole or sleeve at the lower end connects to the top of the gas lift, transmitting the lifting force to the seat while distributing pressure to protect the gas lift.

Technical Differences and Application Scenarios

Low-end bases typically use fixed backrest mechanisms with few gears and rough adjustments; linked bases or synchronous tilt mechanisms use dynamic adaptive support technology to automatically adjust the angle between the backrest and seat cushion according to the user's recline amplitude, suitable for long-term office work or lunch break scenarios. Additionally, the number of locking gears on the base directly affects usage stability: the more gears there are, the less likely the user is to slide when switching between different postures, but the operational complexity also increases accordingly.