Linear bearing/guides

Linear bearings and guides are critical components within Voice Coil Motor (VCM) actuators that enable precise, friction-minimized linear movement of the actuator's moving parts. They maintain alignment and stability while allowing the voice coil to move freely along its axis, ensuring accurate positioning and repeatable motion in applications such as optical focusing systems, precision stages, and micro-positioning devices. These components are designed to operate within a defined range of shaft diameters (8–80 mm), dynamic load ratings (0.3–120 kN), and static load ratings (0.5–150 kN), as listed in the directory. Travel accuracy grades (C3–C5) and repeatability (±0.005–±0.02 mm) are specified per ISO 10285 and other references, but actual values must be confirmed for the specific model and application. Maximum speed ranges from 60 to 300 m/min, limited by lubrication and heat generation. Operating temperature is typically -20 to 80 °C, with high-temperature options available. Vibration amplitude is ≤0.02 mm measured at 10–500 Hz. Lubrication can be grease or oil, depending on maintenance and speed requirements. Sealing classes range from IP54 to IP65, providing dust-tight and water-jet protection. Materials commonly used include stainless steel, chrome steel, and engineering plastics, with material grades such as GCr15 for rails, 440C for balls, and 304 for corrosion resistance, referencing GB/T 18254 and ASTM A276. Weight per unit length varies from 0.1 to 15 kg. These components are selected based on load, speed, accuracy, and environmental conditions. Verification with the manufacturer is essential to ensure compliance with ISO 10285, ISO 14728-1, and IEC 60529 standards for the intended use.

Linear bearings typically use rolling elements (balls or rollers) that circulate within raceways, converting sliding friction into rolling friction. In VCM actuators, they work in conjunction with the electromagnetic force generated by the voice coil to provide constrained linear motion along a single axis while minimizing resistance and wear. The rolling elements reduce friction, allowing smooth and precise movement. The guides maintain alignment and stability, ensuring that the moving parts travel in a straight line without deviation. This principle enables high accuracy and repeatability in positioning applications.