H4-KH-11-D ant mechanical power rating Overview Determinati Helical gear reducer H4

Flender/Flender Gear Units/Helical gear reducer H4

inspectors and media representatives judge engine, wind and driving noise very2 5 Noise Behavior critically in tests. Vehicles are already tted with noise-damping materials at many points, but these involve increases in weight and cost. The most important goal ofthe bevel gear designer is therefore to minimize the excitation arising from the gear teeth themselves. Apart from the macro geometry (gear body), the micro geometry (ease-off), surface structure and gear quality are all of considerable importance fornoise behavior. Their inuences are dealt with in Sects. 5.2.2 and5.3. There are number of ways to minimize running noise. The rst step is to optimize the macro geometry. Here it is important to note that measures taken toincrease the contact ratio may also lead to reduction in load capacity (seeTable 5.. Several basic measures to improve noise properties are listed below. The outside diameter of the wheel has been kept constant in the different possible variations considered. The quantitative statements remain valid even if changing parameter improves some properties of gear but makes other properties dispro-portionately worse. The design of bevel gear set must always take many criteriainto account, and is hence compromise between various requirements. In order toachieve the maximum possible use of the material, it is desirable to balance ankand root load according to safety factors. As will be evident from Table 5.1, it will be benecial in terms of noise emission to compare the results on the basis of thetotal contact ratio and to modify the compromise design in favour of lower noise excitation. In further step, the transmission error and hence the effective contact ratio are calculated by means of micro geometry optimization. The examples usedin the diagrams in this chapter have been selected from large number of produc-tion gear sets and are representative of the complete hypoid gear range employed inrear axle drive passenger cars. Contact Ratio Th