Causes and preventive measures of grinding cracks in carburized and quenched gears of rolling mill
Gear is an important basic part of mechanical products. Gear grinding is a finishing process of gear processing. Gear grinding […]
Gear is an important basic part of mechanical products. Gear grinding is a finishing process of gear processing. Gear grinding […]
Swing rolling, namely swing rolling, also known as axial rolling, is a new plastic processing technology gradually and widely used
1. Processing with Norton 3SG60 grinding wheel (1) rough grinding: the 1st ~ 3rd cutters are in the form of
Figure 1 shows the driven bevel gear of rear axle in 46910 / 37 commercial vehicle. It can be seen
The general plastic precision forming process is precision die forging, which is a less cutting process gradually developed from general
The precision forging process of spiral bevel gear generally has some problems, such as difficult forming, difficult cavity filling, low
Taking the transmission gear of heavy equipment as the research object, the fatigue crack propagation and fatigue fracture of gear
In the process of EDM, the electrode will have a certain amount of burning loss, which will change the electrode
For the finish machining of hardened cylindrical gears, gear grinding technology is a common choice at present. On the premise
The model used for the numerical simulation of gear bending fatigue is the same as that used in the bending
Hypoid gear is widely used in aviation, automobile and other fields. As an important index to predict its dynamic performance,
When rolling the thick cylinder of the pier, the relationship between the feed rate s per revolution and the average
1. Technical analysis of forging process In offshore engineering, the requirements for large herringbone gears are relatively high. The original
When testing the bending fatigue of 42CrMo heavy equipment transmission gear by experimental method, the data results have obvious advantages,
The feed rate per revolution of the cone die is the reduction amount per revolution, which is the reduction amount
Before the formal bending fatigue test, the load level of the test needs to be determined. Pick two from the
For the five kinds of swing head motion trajectories in the figure, they are analyzed one by one as follows:
The bending fatigue characteristic curve and bending fatigue limit stress of the test gear shall be combined according to different
1. Advantages of large herringbone gear in aviation and ocean engineering The diameter of large gears used in aviation and
The motion track of the swing head refers to the projection track of any point on the axis of the
Figure 1 shows the front view of the temperature field on the single tooth profile surface and the middle section
Due to the eccentric load on the workpiece during rotary forging, the metal flow is uneven. If the preform is
The transmission gear of heavy equipment used in the bending fatigue test is designed based on the gear applied in
Among the key areas of China’s planning, marine engineering is the most important project and development field. Marine engineering includes
The so-called “thick piece” revolving body means that the thickness h is greater than or equal to the radius R
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
The essence of swing rolling is a special two roll rolling. In the process of rotary forging, although the swing
In order to verify the correctness of the above crack propagation, the crack length and crack tip stress intensity factor
The cold rotary forging precision forming process of bevel gear is an advanced manufacturing technology. Its process design in actual
The equivalent stress at the crack tip under different crack inclination angles is extracted and plotted, and the equivalent stress
Hypothetical generating wheel is usually used to explain the machining process of bevel gear. It is a virtual bevel gear
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
Hypoid gear is a bevel gear with central axis offset. The tooth surface surface of this type of gear is
At 3 000 n · The equivalent time-varying meshing parameters of hypoid gear in one cycle are calculated according to
The transmission error curves obtained by finite element method and classical TCA method are compared to verify the correctness of
In order to simulate the singularity and discontinuity of element displacement stress, it is realized by constructing the extended functions
According to the established contact fatigue finite element simulation model of hypoid gear transmission system, the finite element simulation software
It can be seen that the fracture clearly presents three regions with different morphological characteristics, as shown in Figure 1.
In recent years, the machining of mechanical parts is developing in the direction of intelligence and efficiency. With the increasing
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
The transmission system of shearer cutting part has the advantages of compact structure and high bearing capacity, and can realize
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
(1) Present situation In the aspect of gear profile, because the involute gear has the advantages of convenient machining and
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
ABAQUS / FE-SAFE is used for joint simulation. The analysis process is as follows: firstly, the fatigue analysis software FE-SAFE
According to the formula, the relationship between LA and FA can be used to change any shape. The machining mechanism
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,
In the 1960s, the Washington Museum exhibited the model of ancient Chinese guide car. According to archaeological evidence, this guide