The amount of channeling should be based on the maximum allowable wear of hobs. Firstly, the allowable gear hobbing channeling of hob is determined by tool modulus and machining accuracy. When the maximum wear limit is reached, it must be sharpened. The determination of gear hobbing tool shifting is...
The gear hobbing and tool shifting on the gear hobbing machine can be completed by manual operation or automatic control on the gear hobbing machine. Automatic control of knife channeling is most suitable for mass production. However, manual gear shifting is usually used for a small number of production...
Most of the inherent accuracy of the gear hob can be destroyed. Therefore, if the tolerance of tooth profile is very small, the diameter jump of automobile gear hob must be strictly controlled. First of all, the jumping of automobile gear hob leads to out of tolerance of tooth...
Calculate the tool travel according to Hoffmeister’s formula: Where: FA — axial tool path of gear hobbing cutting; H1max – the maximum chip thickness at the tooth top of gear hobbing hob, generally 0.2mm is used to determine the axial tool walking amount; Z2 — number of gear teeth;...
As shown in the figure, the tool shifting length of gear hobbing hob is calculated according to the following formula: Where: Ls — tool shifting length of gear hobbing hob; L3 — effective length of gear hob; Le — cutting edge length of gear hobbing hob (minimum length of...
The cutting process of gear hob should be divided into pre machining area and generating area; Most of the metal cut from the gear blank is carried out in the pre cutting area. (1) The pre machining area is located on the side where the gear hob first cuts...
Gear hobbing multi groove hob is shown in the figure. When using gear hobbing multi groove hob, the following conditions shall be met: (1) Ensure that the blade back of the cutter tooth has sufficient service length (grinding times) and sufficient stiffness; (2) There is enough chip holding space...
The selection of gear hobbing multi groove hob has the following advantages: (1) Gear hob has many grooves and good tooth shape; (2) Reduce the cutting load on the rake face, reduce tool wear, and increase the amount of tool travel; (3) It can prolong the cutting time of...
The number of hobs Z0 has an important influence on the machining time In some cases, the use of gear hobbing multi head hob plays a significant role in reducing machining hours The following items shall be considered when selecting the number of heads of gear hobbing hob: (1)...
The selection of large diameter gear hobbing hob has the following advantages: (1) Under the condition of maintaining the same blade back length, more slots can be used to improve the tooth profile accuracy of gear hobbing, and a larger axial tool walking amount can be adopted; (2) Under...