Measurement Background

A large mining machine (crusher) belonging to a certain mining enterprise experienced wear on its core transmission bearings after prolonged operation, necessitating inspection, evaluation, and repair. As the frame serves as the carrier for core components such as bearings, it has high manufacturing precision requirements. Traditional maintenance methods rely on manual experience to judge wear location and severity, resulting in low efficiency and difficulty in ensuring precision. To ensure that the repaired frame meets the equipment's normal operating precision requirements (error ≤ 0.1mm) after assembling components like bearings, and to improve measurement and maintenance efficiency while reducing downtime, the client chose API's Radian laser tracker measurement system. This digital inspection technology enables precise diagnosis of geometric tolerance data related to the large equipment frame and verifies repairs.

Measurement Requirements and Challenges

1. High Precision Requirement: Every critical position on the frame will serve as a connection node for important components; therefore, high detection precision is required, with tolerances less than 0.1mm;

2. High Efficiency Requirement: Downtime for maintenance of large mining machinery causes economic losses every minute and second for the enterprise, making high efficiency a mandatory requirement for maintenance. In this measurement, it was required to complete wear diagnosis and repair verification within a few hours;

3. Complex Working Conditions: The available space at the site for measurement operations is limited, and there are challenges from factors such as temperature fluctuations.

Figure 1: Mining Machine Frame to be Inspected in This Case

Figure 2: API Series Laser Trackers (Models from left to right: Radian Plus / Radian Pro / Radian Core / iLT / iLTx)

Advantages of Using API Laser Trackers for Measurement

1. High-Precision Measurement: The Radian laser tracker utilizes advanced laser measurement technology. Its built-in interferometric laser (Pro model) and absolute laser (Pro/Plus/Core models) ensure high precision and stability in measurements. It achieves micron-level measurement accuracy (μm, 1/1000mm). In this case, it fully meets the enterprise's requirement for measurement accuracy better than 0.1mm;

2. High Efficiency and Speed: The Radian laser tracker has a sampling rate of up to 1000 points/second, enabling rapid acquisition of a large number of measurement points in a short time, significantly improving measurement efficiency. Its single-operator capability, along with auxiliary features such as quick clamping devices and expandable accessories with fast connections, further reduces measurement preparation and operation time;

3. Portability and Flexibility: The Radian laser tracker features a compact design with a main unit weighing less than 10 kg, facilitating portability and installation. It can be installed horizontally, vertically, upside down, or tilted, allowing flexible setup even in the limited-space measurement environment of this case;

4. Automation and Intelligence: The Radian laser tracker is equipped with an iVision target ball automatic recognition and locking function. Even under conditions of lost optical signal, it can automatically search for and lock the target ball, reducing manual intervention and enhancing the degree of measurement automation;

5. Automatic Environmental Compensation: The Radian series laser trackers integrate a meteorological station system capable of real-time identification of material temperature, air temperature, air humidity, and air pressure fluctuations at the measurement site. It implements automatic compensation based on requirements, minimizing interference from external factors to the greatest extent.

6. Continuous Refinement: API's latest iLT series laser trackers build upon the robust performance of the Radian series through further integration and optimization. They reduce the main unit size and weight by nearly 50% compared to the Radian series, easily adapting to extreme narrow-space measurements, portable field use, and various automated production line integration applications.

Figure 3: Portability Demonstration of the iLT Laser Tracker

Figure 4: Measurement Site in This Case

Figure 5: Measurement Site in This Case

Measurement Process

1. Equipment Setup: In this case, the operator positioned the Radian laser tracker at a suitable location around the mining machine frame to be measured, ensuring that the measurement range covered the entire target area;

2. Data Acquisition: The operator used the laser tracker's Spherical Mirror Reflector (SMR) with an embedded prism to touch the bearing positions to be measured. The Radian laser tracker emitted a laser beam and locked onto the center of the SMR in real time. When the operator stabilized the SMR at the measurement point or issued a data acquisition command, the Radian laser tracker measured the 3D coordinates of the target point at a sampling rate of 1000 Hz (1000 points per second), and transmitted the measurement data in real time to software on the computer for recording and subsequent analysis.

3. Data Analysis: After data acquisition was completed for all points, the acquired coordinate data was analyzed using measurement software. By constructing corresponding lines, planes, solids, and importing digital models, the specific location and magnitude of the bearing damage were determined. This measurement data served as a basis for welding repair and grinding restoration of the bearing;

4. Re-measurement: After frame repair, the above measurement steps were repeated to compare and verify the measurement data of the repaired position until a satisfactory result was achieved.

Measurement Results and Repair

Through precise measurements by the Radian laser tracker, the damaged locations and magnitudes of the frame were successfully evaluated. These data provided strong support for subsequent repairs.

After repair completion, the Radian laser tracker was used again to re-measure the repaired mining machine frame. The re-measurement results showed that the frame had been restored to a state capable of normal operation, demonstrating excellent performance.

Figure 6: Measurement site of this case

Summary

API’s Radian series and iLT series laser trackers have played a significant role in the measurement and maintenance of large-scale mining machinery frames, thanks to their high precision, efficiency, portability, flexibility, and automated intelligence.

They not only met the enterprise's strict requirements for measurement accuracy and efficiency but also provided reliable data support for component repair. Ultimately, the repaired components passed the re-measurement, resumed normal working conditions, and ensured the stable operation of large-scale mining machines.

This application fully demonstrates the strong advantages of API’s various series of laser trackers in industrial equipment maintenance, providing valuable references for the measurement and repair of similar equipment.