Research On Modification And Scuffing Of High Contact Ratio Spur Gear Considering Tooth Elastic Deformation

Gear is the most commonly used transmission part in machinery.Spur gear occupies an important position in the aviation field due to its simple structure,good economy,and no axial force when meshing.At the same time,high coincidence（HCR）spur gears have smooth meshing and low comprehensive meshing rigidity,which play an indispensable role in gear transmission.However,because HCR spur gears have a larger tooth tip height than normal coincidence（NCR）spur gears,the relative sliding speed of the tooth surface increases,and the risk of tooth surface adhesion increases.In response to this problem,the modification and gluing temperature calculations of HCR spur gears were studied,the modification calculations of the gears and the contact temperature calculations at various points on the meshing surface were studied,and the tooth surface contact temperature distribution was improved through gear modification.The main research contents are as follows:（1）According to the meshing characteristics of high coincidence gears,the deformation and stiffness of the gear teeth are analyzed and calculated,and the load distribution between the teeth is calculated,and the accuracy of the theoretical calculation is verified through experiments.The effect of changing gear tooth parameters on the load distribution between teeth is studied.The results show that when the addendum height coefficienth_a^* increases from1.25 to 1.4,the maximum load sharing rate decreases by about 4.3%;when the pressure angleαdecreases from 21.45°to 14°,the maximum load sharing rate decreases by about 13.5%;When the number of teeth increases from 29 to 300,the maximum load sharing rate decreases by about 6.0%;when the displacement coefficient decreases from 0.11 to-0.5,the maximum load sharing rate decreases by about 14.4%;when the error changes from 0 to 5×10^-6m When,the maximum load sharing rate of the gear teeth increased by about 8.0%.The load sharing rate at the engagement point is not significantly affected by the change of the addendum height coefficient,the pressure angle,the number of teeth,and the displacement coefficient,but is more obviously affected by the deviation of the base section.Therefore,when designing gears considering the anti-gluing performance of the gear,reasonable gear tooth parameter design can reduce the load between teeth and theoretically improve the anti-gluing ability of the gear.（2）Using the flash temperature method,calculate the contact temperature of each point on the tooth surface by modifying the load of each point on the tooth surface during flash temperature calculation,and obtain the contact temperature distribution curve on the tooth surface through program design.According to the analysis,the lowest point of the tooth surface temperature of NCR and HCR gears is at the node,where the relative sliding speed of the tooth surface is equal to zero;the highest point of the NCR gear tooth surface temperature is at the engagement point,where the gear teeth are more loaded than the entire tooth.The surface is the lowest,but the sliding speed between the teeth is the largest,and there is an additional impact load;the highest point of the HCR gear tooth surface temperature is also located at the engagement point,where the load on the gear teeth is the smallest than the entire tooth surface,and the sliding speed between the teeth is the same Maximum,and additional biting impact load at the same time.（3）For the purpose of reducing the tooth surface contact temperature,the specific parameters of the gear tooth profile modification are calculated,and the distribution of the tooth surface contact temperature along the tooth surface after the modification is calculated.After modification,the highest point of the tooth surface temperature of the NCR and HCR gears moves toward the pitch circle.Under the optimal modification amount,the temperature at the root and tip of the tooth is reduced to equal to the body temperature,and the maximum temperature of the NCR gear tooth surface is reduced by 12.83%;The maximum temperature of the gear tooth surface is reduced by 12.89℃.Tooth profile modification significantly improves the contact temperature at the root of the tooth tip of the gear tooth,reduces the maximum temperature of the tooth surface,and improves the anti-gluing ability of the gear tooth.（4）Carried out the test and verification of the gluing load capacity of gears,using wireless signal memory to store data information,determine the location of key temperature measurement points,measure the tooth surface contact temperature of each temperature measurement point,and compare the test results with the theoretical calculation results to verify The correctness of the theoretical calculation formula.