Do You Know Anything About Linear Bearings?

A linear bearing is a mechanical component used for linear motion, typically consisting of an outer cylinder, a cage, and rolling elements (such as steel balls or rollers). It achieves low-friction linear guidance through the cyclic motion of the rolling elements and is widely used in automated equipment, precision instruments, and other fields. Its core characteristic is allowing shafts (such as optical shafts) to reciprocate at high speeds with low resistance along the axial direction.

Example: INA KN16-B-PP
KN16: Bearing inner diameter is 16mm (suitable for 16mm optical shafts)

B: Indicates the bearing has an open design (to compensate for installation errors or slight off-center loads)

PP: Material is glass fiber reinforced plastic (PPS), corrosion-resistant, lightweight, suitable for humid or chemical environments.

Features: Open design allows for radial fine-tuning, facilitating installation.

Rolling elements are steel balls, low friction, high precision. Suitable for medium loads and high-speed linear motion.

Mainly used in automated production lines, packaging machinery, medical equipment, and other applications requiring linear guidance.

Differences between Linear Bearings and Others

Differences between Linear Bearings and Rotary Bearings: Linear bearings support linear motion, while ordinary bearings (such as deep groove ball bearings) support rotary motion.

Differences between Linear Bearings and Linear Guides: Linear bearings have a simpler structure and lower cost, but their load-bearing capacity and rigidity are generally lower than those of linear guides.

A smooth shaft, also known as a linear axis, guide shaft, or hard shaft, is a high-precision, smooth-surfaced cylindrical metal shaft. It is typically used in conjunction with linear bearings to achieve low-friction linear reciprocating motion.

Materials are typically: high-carbon steel (SUJ2), stainless steel (such as 440C), or chrome-plated steel.

Precision grades: General grade (h5~h7): for general industrial applications.

Precision grade (h4~h5): for high-precision equipment (such as CNC machine tools and measuring instruments).

Surface roughness is typically required to be Ra≤0.4μm to ensure smooth operation with linear bearings.

Type: Ordinary smooth shaft: fully chrome-plated, suitable for general loads.

Hardened optical shaft: integrally quenched and chrome-plated for enhanced load-bearing capacity.

Stainless steel optical shaft: corrosion-resistant, suitable for special environments such as food and medical applications.