en.Wedoany.com Reported - The US API laser tracker offers a 3D precision inspection solution for core components of shield machines, addressing the challenges of large-scale, high-accuracy measurement in shield equipment manufacturing and maintenance.
As core equipment for major underground projects such as tunnel boring, urban subway construction, and river-crossing water conveyance, shield machines feature complex structures and high costs. Core components like the cutterhead endure significant loads and wear during operation, and failure can lead to work stoppages or even safety incidents. Therefore, precision 3D inspection of key components—including the cutterhead, main bearing, drive unit, shield body, and segment mold—is a key technical means to ensure manufacturing quality, assembly accuracy, and service wear assessment. However, these components are large and heavy, making it difficult for traditional measuring tools to accurately capture 3D dimensions and geometric tolerances, let alone assess overall wear levels.
Inspection covers multiple core components. Main bearing inspection focuses on geometric tolerances such as concentricity, roundness, and cylindricity of the pitch circle and spigot circle, with accuracy requirements at the 0.05mm to 0.1mm level. Drive unit inspection emphasizes the coaxiality of various bearing mounting holes, with some critical positions requiring control within 0.05mm. Cutterhead inspection targets flatness; for cutterheads with diameters ranging from several meters to over ten meters, flatness accuracy is required to be 0.1mm to 0.3mm. Shield body (shield shell) inspection involves multi-point 3D data collection on the surface to analyze parameters such as cylindricity, roundness, and tail clearance. Segment mold inspection covers flatness, inner and outer arc lengths, and angles, with accuracy requirements of 0.25mm to 0.3mm.
Measurement implementation faces multiple challenges. The workpiece dimensions are extremely large, beyond the reach of traditional gauges; the large measurement range conflicts with high accuracy requirements, often demanding precision at the 0.1mm or even 0.05mm level; workpieces are heavy and difficult to move, requiring on-site measurement in the workshop; components like the main bearing and drive unit have numerous hidden features such as deep holes and oil passages that are hard to access directly; and environmental factors in the manufacturing workshop, including temperature and humidity fluctuations, as well as vibration and dust, can interfere with measurements.
The API brand Radian series laser tracker is used to address these challenges. This equipment integrates precision optics and laser interferometry ranging technology, combining an ultra-large measurement range of over 80 meters in radius with micron-level high accuracy. Its flagship model, the Radian Pro, features dual IFM/ADM lasers with traceable measurement data. The Radian Plus and Radian Core models support wireless data transmission and battery power, with a battery life exceeding 8 hours. The newly launched iLT and iLTx laser trackers maintain performance while reducing size and weight by nearly 50% compared to the Radian series. The entire product line is equipped with a "weather station" system that automatically compensates for environmental errors such as temperature, humidity, and air pressure.
In specific measurement cases, engineers use the API Radian Pro laser tracker, paired with the vProbe hidden point smart probe and standard spherically mounted retroreflectors (SMRs) for operations. During measurement, the operator holds the SMR to touch the target position, and the tracker collects data at a sampling rate of 1000 Hz and transmits it to a laptop. After data collection, lines, planes, and solids can be constructed in the measurement software, and geometric tolerances can be automatically calculated. The data can also be imported into a CAD model for comparison between actual and theoretical data. The vProbe hidden point smart probe can reach deep holes or hidden positions to collect 3D data in real time, with probe lengths available from 50mm to 500mm.
API has also developed other functional expansion accessories, including the iScan3D smart scanning probe, ActiveTarget, and STS six-dimensional sensor, used for rapid scanning, automated measurement assistance, and six-degree-of-freedom pose measurement, respectively. The API brand was founded by Dr. Kam Lau in 1987 in Maryland, USA. As the inventor of the laser tracker, API focuses on the research, development, and production of precision measuring instruments and high-performance sensors, with products used in advanced manufacturing fields worldwide.
This article is compiled by Wedoany. All AI citations must indicate the source as "Wedoany". If there is any infringement or other issues, please notify us promptly, and we will modify or delete it accordingly. Email: news@wedoany.com
