Bending Strength Calculation of Heavy Duty Gear Rack Root
For the calculation of heavy load large module gear and rack drive, there are many literature research calculation methods, some […]
For the calculation of heavy load large module gear and rack drive, there are many literature research calculation methods, some […]
The gear rack with large module and heavy load is not suitable for the conventional hobbing and slotting processing method.
With the rapid development of China’s economy, mining machinery, engineering machinery, marine engineering equipment and other heavy machinery and equipment
In order to verify the actual effect of domestic R&D and manufacturing of heavy gears, Shendong Coal Group Co., Ltd.
The whole process of heavy gear processing shall strictly control the quality and make tracking records, and must be tested
By using the professional heavy gear simulation analysis software, combined with the actual measurement parameters and working condition parameters, the
Refer to the commonly used materials for heavy gear processing in China, consult the steel brand manual, and compare the
Based on TCA technology, the corresponding high-speed and heavy-duty spiral bevel gear surface impressions and transmission error curves before and
Since the coincidence degree and the transmission error amplitude at the transition of high-speed and heavy-duty spiral bevel gears are
Without considering the elastic deformation of the tooth surface (assuming that the gear is completely rigid), a pair of local
In the fields of aerospace vehicles, high-speed and heavy-duty spiral bevel gears, as the key of the transmission system, have
The spiral bevel gear of heavy vehicles generally adopts high-strength alloy steel such as 30CrMnTi. This kind of steel is
Heavy duty spiral bevel gear has many excellent characteristics, such as stable transmission performance, low noise, large transmission torque and
Taking the transmission gear of heavy equipment as the research object, the fatigue crack propagation and fatigue fracture of gear
The model used for the numerical simulation of gear bending fatigue is the same as that used in the bending
When testing the bending fatigue of 42CrMo heavy equipment transmission gear by experimental method, the data results have obvious advantages,
Before the formal bending fatigue test, the load level of the test needs to be determined. Pick two from the
The bending fatigue characteristic curve and bending fatigue limit stress of the test gear shall be combined according to different
The transmission gear of heavy equipment used in the bending fatigue test is designed based on the gear applied in
The test adopts the form of single tooth loading. It is necessary to design special fixtures according to the standard
The stress ratio r = 0.6, the number of cycles n corresponding to the stress intensity factor at the crack
In order to verify the correctness of the above crack propagation, the crack length and crack tip stress intensity factor
The equivalent stress at the crack tip under different crack inclination angles is extracted and plotted, and the equivalent stress
The dynamic continuous growth of fatigue crack is realized by resetting the crack length each time. In the numerical simulation
Study the crack propagation law when the initial crack position H0 is 60mm, 62mm, 64mm, 66mm, 68mm and 70mm respectively,
Fig. 1 shows 150, 300, 500 and 1000 times SEM images of fatigue fracture in the instantaneous fracture zone. The
In the actual process of gear meshing, the maximum contact stress usually acts on the tooth surface of the pinion.
Under the continuous loading of cyclic loading and unloading, the slip band around the crack tip deforms, resulting in the
In order to simulate the singularity and discontinuity of element displacement stress, it is realized by constructing the extended functions
It can be seen that the fracture clearly presents three regions with different morphological characteristics, as shown in Figure 1.
The morphological characteristics of fracture reflect the quality of materials and play an important role in material quality inspection, fault
Under the influence of crack shape, the change of mode I stress intensity factor is studied. In the process of
Under the action of cyclic load, cracks begin to appear and grow, and the remaining life of the sample is
Under the set parameters, the gear model is simulated. As shown in the figure, the trend distribution of stress intensity
By referring to the national standard GB / t6398-2000 test method for fatigue crack growth rate of metallic materials, the
The modeling module of ABAQUS software can effectively establish three-dimensional models, but most of them are suitable for three-dimensional model
The fatigue crack evolution test and numerical simulation of transmission gears of heavy equipment are studied. The preparation of compact
The characteristics of crack propagation under the influence of external force factors are as follows: 1) The crack surface is
The transmission gear of heavy equipment has low rotation speed in the process of transmission operation, but needs to bear
Through verification, 40 test data under 5 load levels meet the requirements of lognormal distribution. Therefore, the distribution function f
J. Kmmberger proposed that it is necessary to carry out anti fatigue design for mechanical components bearing periodic load. Therefore,
According to the differences of loading methods, structural types and working modes of gear test devices, they can be divided
Robert Basan proposed a mathematical model of slip line contact and a multiaxial fatigue life calculation model based on Fatemi
The main form of gear failure is bending fatigue failure. According to the failure physical stress intensity model, it is
He Xiaohua of Chongqing University analyzed and studied the bending fatigue strength of 20CrMoH gear. Combined with mathematical statistics theory
As an important index of engineering fracture analysis, stress intensity factor is adopted by most scholars. The proposal of stress
At present, the research of gear bending fatigue reliability test mainly focuses on how to improve the bearing capacity of
Multiply both sides of Paris formula by Da and integrate to obtain the formula: By substituting the stress ratio r
The research on the method of compound mode crack propagation is mainly through numerical simulation and experimental research. For the
Comparing the solid line and dotted line in Figure 1, for the same material, the value of plane stress under
Yang carried out a series of fatigue tests on C45 steel samples with local surface cracks. The effects of carburizing
As the carrier of simulation calculation, grid plays a decisive role in the quality of simulation results. The selection of
Due to the importance of small fatigue cracks, many researchers at home and abroad have carried out extensive research on
1) Define the ultimate load and maximum fatigue load The sample is fixed on the fixture by two round pins.
Different types of cracks have their own stress and displacement: type 1 crack is subjected to tensile stress perpendicular to
The whole fatigue process includes three stages: crack initiation, crack propagation and fracture failure caused by final instability propagation. The
The fatigue fracture process of metal materials can be divided into three stages: crack initiation, propagation and instantaneous fracture. In
According to the formula, the stress intensity factors Ki, Kii and kiII are mainly used to characterize the stress field
At present, the research on the law of fatigue crack growth mainly uses experimental methods and numerical analysis methods. According
1) 42CrMo steel was studied by means of experiment and simulation, and various factors affecting fatigue crack propagation under different