Bevel gear is a component that can drive according to a stable transmission ratio. Because of its high transmission efficiency, high bearing capacity, stable transmission, wear resistance and compact structure, it is widely used in mechanical products such as automobiles and tractors. In order to prevent the involute tooth surface of bevel gear from being roughened and reduce noise and impact, it is necessary to trim the tooth top of bevel gear.
1. Impossible to trim the edge while cutting the teeth
In the process of bevel gear machining, because the modulus at both ends of bevel gear teeth is different, and the tooth thickness and tooth height are also different, using the current gear cutting technology can not form trimming at the same time as cylindrical gear. In the manufacturing process of bevel gear, the machining quality of bevel gear tooth surface is usually judged by adjusting the position, size and shape of meshing gear contact area, and the detection of bevel gear tooth surface is less. In practical application, the top part of the tooth does not participate in meshing, and the force and motion are mainly transmitted by the middle of the tooth. Based on the above reasons, the bevel gear top trimming technology was not popularized and applied in the gear processing industry before. With the increase of gear load and linear speed during meshing, the bevel gear top trimming technology began to be applied gradually.
2. Manual grinding and trimming
Due to the current technical limitations, the tooth top trimming of spiral bevel gears cannot be realized during tooth manufacturing. The common tooth top trimming of spiral bevel gears mainly adopts manual trimming. Use the angle grinder as a tool to carry out fitter trimming on the tooth top of spiral bevel gear, as shown in Figure 1. The use of manual grinding for trimming depends on experience. The size consistency and uniformity are poor, the efficiency and precision are low, and the labor intensity is high, which can not meet the needs of mass production. The following problems still exist in manual trimming: ① during manual trimming, dust is formed by grinding wheel and iron filings, which affects the normal breathing of operators; ② During manual trimming, the friction between the grinding wheel and the workpiece generates huge heat, resulting in great paste smell and bad smell on site; ③ Wind (electric) grinding wheel is generally used in manual trimming, which has high noise and potential safety hazards.