rullatuki

Rullatuki is a Finnish term for a roller support used in mechanical and structural engineering. It refers to a support arrangement in which loads are transmitted through cylindrical rollers that roll between contacting surfaces, reducing friction compared with sliding supports. The arrangement allows vertical reaction forces to be carried while permitting horizontal movement of the supported member, which helps accommodate thermal expansion, deflection, and misalignment.

Typical configurations include single-roller or multi-roller layouts, arranged in lines or grids under beams, machinery beds, or bridge bearings. The rollers are usually supported by a fixed frame or a carriage and may use plain bearings, roller bearings, or low-friction coatings. Materials vary; steel is common, with rubber or synthetic coatings to reduce wear and noise. In operation, the rollers rotate as the supported member slides or expands, preventing binding.

Applications include structural bearings for bridges and buildings, crane runways, machine-tool beds, conveyors, and stage or exhibition equipment. The performance depends on roller diameter, spacing, load distribution, and lubrication. Although rullatuki designs provide low friction and simple construction, they require regular maintenance to monitor wear, alignments, and lubrication, especially under variable loads or in dirty environments.