Application of CMM in gear quality inspection

Gears are wheel-shaped mechanical parts that rely on the meshing of teeth to transmit torque. The gear can realize the functions of changing the speed and torque, changing the direction of movement and changing the form of movement through transmission with other toothed mechanical parts (such as another gear, rack, worm). Due to the advantages of high transmission efficiency, accurate transmission ratio, and large power range, gear mechanisms are widely used in industrial products, and their design and manufacturing level directly affect the quality of industrial products.

Although some special measuring instruments used in traditional gear measurement (such as double-sided meshing checker, periodic measuring instrument, etc.) can measure the gear error more accurately, they can only be used for the measurement of specific error items, and their versatility is relatively low. poor, and the measurement results are easily affected by human factors. 

As a general-purpose measuring instrument, CMM has been widely used in precision measurement and product quality control due to its advantages of high precision, strong function and convenient operation. The CMM can be equipped with a special gear measurement software module, which can measure gears with high precision and high efficiency. The measuring machine records the coordinates of the measured point through a high-precision probe, and obtains the error value by comparing with the theoretical value.

CMM application advantages

1. It can evaluate the tooth profile error (comprehensive error, profile error, pressure angle error) of the gear; tooth profile error (comprehensive error, profile error, helix angle error); pitch deviation; adjacent pitch error; tooth pitch error Error parameters such as distance cumulative error and gear radial runout.

2. It can also measure and evaluate the gear tooth thickness, common normal length, span distance and other parameters.

3. According to different standards (such as ISO, DIN, JIS, AGMA, GB, BS, etc.), the result of the measured gear can be automatically judged.

4. The measurement and evaluation of gears are simple and intuitive to operate. The three-dimensional mathematical model of the gear to be measured can be automatically generated according to the gear module, number of teeth and pressure angle and other parameters. According to the measurement requirements, the measurement path can be displayed intuitively, and the entire gear measurement detection process can be simulated.

5. The software can automatically define the number and angle of stylus required for measurement according to the condition of the gear to be measured, and can automatically correct each stylus defined. At the same time, the stylus used in the measurement can also be manually selected, and the diversified selection provides the operator with more operation methods.

6. Intuitive and concise measurement operation interface. The operator only needs to fill in the relevant gear parameters such as module, number of teeth and pressure angle according to the prompts on the software interface, and drag the positioning element in the corresponding position to locate the position of the tested gear. And can automatically measure gears. The operator can also select and measure gear parameters such as tooth shape, tooth direction and tooth pitch according to their own needs.

7. The evaluation of the gear results and the output of the measurement report are simple and convenient. Just drag the measured gear into the report display area, and the gear parameter errors such as tooth shape and tooth direction will be displayed. And for each gear data measured, it can visually indicate whether it is qualified or out of tolerance by color. A rating can also be given for each measurement data. The test results can be saved, and the test result report can also be printed out.