Grinding of Gleason tooth and Skiving of Kinberg tooth

When the number of teeth, modulus, pressure angle, helix angle and cutter head radius are the same, the strength of the arc contour teeth of Gleason teeth and the cycloidal contour teeth of Kinberg are the same. The reasons are as follows:

1). The methods for calculating the strength are the same: Gleason and Kinberg have developed their own strength calculation methods for spiral bevel gears, and have compiled corresponding gear design analysis software. But they all use the Hertz formula to calculate the contact stress of the tooth surface; use the 30-degree tangent method to find the dangerous section, make the load act on the tooth tip to calculate the tooth root bending stress, and use the equivalent cylindrical gear of the tooth surface midpoint section to approximate Calculate the tooth surface contact strength, tooth high bending strength and tooth surface resistance to gluing of spiral bevel gears.

2). The traditional Gleason tooth system calculates the gear blank parameters according to the end face modulus of the big end, such as the tip height, the tooth root height, and the working tooth height, while Kinberg calculates the gear blank according to the normal modulus of the midpoint. parameter. The latest Agma gear design standard unifies the design method of the spiral bevel gear blank, and the gear blank parameters are designed according to the normal modulus of the midpoint of the gear teeth. Therefore, for the helical bevel gears with the same basic parameters (such as: number of teeth, midpoint normal modulus, midpoint helix angle, normal pressure angle), no matter what kind of tooth design is used, the midpoint normal section The dimensions are basically the same; and the parameters of the equivalent cylindrical gear at the midpoint section are consistent (the parameters of the equivalent cylindrical gear are only related to the number of teeth, pitch angle, normal pressure angle, midpoint helix angle, and midpoint of the tooth surface of the gear. The diameter of the pitch circle is related), so the tooth shape parameters used in the strength check of the two tooth systems are basically the same.

3). When the basic parameters of the gear are the same, due to the limitation of the width of the tooth bottom groove, the corner radius of the tool tip is smaller than that of the Gleason gear design. Therefore, the radius of the excessive arc of the tooth root is relatively small. According to gear analysis and practical experience, using a larger radius of the tool nose arc can increase the radius of the excessive arc of the tooth root and enhance the bending resistance of the gear.

Because the precision machining of Kinberg cycloidal bevel gears can only be scraped with hard tooth surfaces, while Gleason circular arc bevel gears can be processed by thermal post-grinding, which can realize root cone surface and tooth root transition surface. And the excessive smoothness between the tooth surfaces reduces the possibility of stress concentration on the gear, reduces the roughness of the tooth surface (can reach Ra≦0.6um) and improves the indexing accuracy of the gear (can reach GB3∽5 grade accuracy). In this way, the bearing capacity of the gear and the ability of the tooth surface to resist gluing can be enhanced.

4). The quasi-involute tooth spiral bevel gear adopted by Klingenberg in the early days has low sensitivity to the installation error of the gear pair and the deformation of the gear box because the tooth line in the direction of the tooth length is involute. Due to manufacturing reasons, this tooth system is only used in some special fields. Although Klingenberg’s tooth line is now an extended epicycloid, and the tooth line of the Gleason tooth system is an arc, there will always be a point on the two tooth lines that satisfies the conditions of the involute tooth line. Gears designed and processed according to the Kinberg tooth system, the “point” on the tooth line that satisfies the involute condition is close to the big end of the gear teeth, so the sensitivity of the gear to the installation error and load deformation is very low, according to Gerry According to the technical data of Sen company, for the spiral bevel gear with arc tooth line, the gear can be processed by selecting a cutter head with a smaller diameter, so that the “point” on the tooth line that meets the involute condition is located at the midpoint and the big end of the tooth surface. In between, it is ensured that the gears have the same resistance to installation errors and box deformation as the Kling Berger gears. Since the radius of the cutter head for machining Gleason arc bevel gears with equal height is smaller than that for machining bevel gears with the same parameters, the “point” that satisfies the involute condition can be guaranteed to be located between the midpoint and the big end of the tooth surface. During this time, the strength and performance of the gear are improved.

5). In the past, some people thought that the Gleason tooth system of the large module gear was inferior to the Kinberg tooth system, mainly for the following reasons:

  ①. The Klingenberg gears are scraped after heat treatment, but the shrinkage teeth processed by Gleason gears are not finished after heat treatment, and the accuracy is not as good as the former.

  ②. The radius of the cutter head for processing shrinkage teeth is larger than that of Kinberg teeth, and the strength of the gear is worse; however, the radius of the cutter head with circular arc teeth is smaller than that for processing shrinkage teeth, which is similar to that of Kinberg teeth. The radius of the cutter head made is equivalent.

  ③. Gleason used to recommend gears with a small modulus and a large number of teeth when the gear diameter is the same, while the Klingenberg large-modulus gear uses a large modulus and a small number of teeth, and the bending strength of the gear mainly depends on the modulus, so the gram The bending strength of Limberg is greater than that of Gleason.

At present, the design of gears basically adopts Kleinberg’s method, except that the tooth line is changed from an extended epicycloid to an arc, and the teeth are ground after heat treatment.