Currently, the testing instruments and equipment in China's gear industry are extremely scarce. This has resulted in a lack of reliable testing data for the quality of over 20 million gearboxes produced annually in China. To thoroughly improve the backward status of internal quality of parts in China’s gear industry, it is necessary to place emphasis on and strengthen the development of testing instruments and equipment. At present, among the gear manufacturers in China's gear industry, only about 300 factories have basic instrument-equipped metrology rooms, with a total of more than 200 three-coordinate measuring machines, most of which are imported from abroad. There are over 1,000 various types of (mechanical, optoelectronic, CNC) gear measurement instruments, including more than 30 gear measuring centers. These instruments are manufactured by foreign companies such as MAAG, Klingelnberg, Hofler, Carl Mahr, M&M, Taylor Hobson, Zeiss, SIP, etc. There are also more than 500 various types of measuring instruments such as roundness testers, length testers, optical indexing heads, roughness testers, projectors, universal measuring microscopes, etc. The remaining approximately 200 gear production plants have very few precision measurement instruments; some factories, apart from having universal gauges, do not have a single measuring instrument. Among the measuring instruments, there are only about ten set testing instruments and worm pairs inspection instruments, while the number of gearbox assembly test benches and drive axle test benches nationwide does not exceed 50. Many factories lack essential instruments such as noise testers and torsional vibration testers. In the process of gear manufacturing, it is necessary to conduct strict inspections and controls on the required quality of product parts, components, and assemblies. Therefore, advanced and applicable measurement technology and instruments are essential conditions. Regardless of whether the gear transmission parts are self-made or purchased externally in various machinery factories, they should be equipped with gear, thread, and spline measurement instruments; otherwise, it will be impossible to control the manufacturing quality of the transmission parts. Currently, domestic Chengdu Tool Research Institute, Harbin Precision Measuring Instrument Factory, and others can basically meet the requirements for gear, thread, and spline measurement instruments. Even for gear measuring centers, gear tool measuring centers, gear pair and worm pair inspection instruments, laser dynamic screw measuring instruments, domestic suppliers can provide them. However, for users with high technical requirements and sufficient financial resources, importing foreign gear measuring centers can also be considered.
Gears, worms, screws, and other transmission components must be supported by cast iron, aluminum alloy, or welded box bodies with very high precision and complex structures. These box bodies have a large number of precise holes and planes that need to be measured for dimensional accuracy and positional accuracy. Therefore, every gear factory should be equipped with three-coordinate measuring instruments of different specifications and precisions.
To further improve the product quality of China's gear industry and enhance industry competitiveness, corresponding types of precision testing instruments should be equipped as soon as possible. In the coming years, China's large and medium-sized gear enterprises should be equipped with three-coordinate measuring machines, gear measuring centers, and other precision measuring instruments, as well as fully equipped central metrology rooms. Small enterprises should also be equipped with necessary precision measuring instruments to ensure the quality of China's gear products.