Strength of bevel gearsA pair of closed straight bevel gears, which need reciprocating operation (i.e., positive and reverse). The transmission ratio is 1, the number of teeth is Z1=Z2=20, the modulus is 2.5, and the torque of transmission is 160N.M. The speed is 180r/min, and cantilever support is adopted. Material is 20Cr, carburizing, quenching, tooth surface hardness HRc58 ~ 63, long-term work. Is the strength of the gear adequate? If not enough, what's the required modulus?
(two) calculation of bending fatigue strength of tooth root;When the gear teeth are loaded, the bending moment of the tooth root is the largest, so the bending fatigue strength at the root is the weakest. When the gear teeth are engaged at the top of the tooth, it is in the meshing zone of double teeth. At this moment, the moment of force of the bending moment is the largest, but the force is not the maximum, so the bending moment is not the maximum. According to the analysis, the maximum bending moment of the tooth root occurs at the highest point of the meshing point of the gear pair. Therefore, the bending strength of the tooth root should be calculated according to the load acting on the highest point of the single tooth meshing zone. Because of the complexity of this algorithm, it is usually only used in high precision gear drives (such as gear drive with 6 degree of accuracy).For low precision gear manufacturing (such as 7, 8, 9 grade precision), due to manufacturing errors, in fact in the addendum. By engaging gears sharing more load, for the convenience of calculation, the bending strength is usually at full load in the addendum to the calculation of tooth. Of course, with this algorithm, the bending strength of the gear is more than enough.
(1) force analysis of gear teethWhen calculating the strength of a gear, it is first necessary to know the force on the gear, which requires the analysis of the force acting on the gear. Of course, the force analysis of the gear drive is also necessary to calculate the shaft and bearing of the gear.Generally, the gear drive is lubricated, and the friction between the meshing teeth is usually very small. The calculation of the force of the gear teeth can not be considered.The normal load Fn acting on the gear surface along the meshing line is perpendicular to the tooth surface. In order to facilitate the calculation, the normal load Fn is broken into two mutually perpendicular force components at the node P, namely the circumferential force Ft and the radial force Fr,
You're not looking for someone to help you figure it out? We have designed it. It takes one dayStrength calculation of 6.3 standard spur gear drive
Strength checking is a very complex problem that requires calculation and strength checking before it is known. If you don't have a program, you can refer to the gear design manual. The cantilever support also needs to know its cantilever length. Strength calculation is divided into two aspects, one is bending strength, the other is contact fatigue strength, the former is closely related to modulus, and the latter is not related to modulus. Because of positive inversion, but also the impact strength of the calibration, it is very complicated.
