When selecting gears based on use, which do we have to consider mainly, the bending strength or the surface durability?
– In general, boththe bending strength and the surface durabilityare to be considered. How-ever, there are some cases where the bending strength is more important. Such cases are:a) the frequency of gear use is low,b) gears are operated by hand without the help of electricity,c) gears to mesh at a low speed. In any case, the decision has to be made by the design engineer.top10) Direction of spiral (or hand of helix), and direction of thrust.- The meshed gears develop, under operating conditions, thrust force. The only exception is spur gears, where the teeth are straight and parallel to shaft axis. For relations between the direction of spiral and the direction of thrust on each type of gear, please refer to KHK3009 catalog:* For helical gears and helical racks*Click here* For spiral miter gears*Click here* For spiral bevel gears*Click hereIn the case of straight bevel gears, the thrust is always backward toward the hub.
