This work presented the characteristics of two gear teeth finishing methods, due to the properties of gear teeth surface layer obtained at the tooth working depth. These methods are: 1) the teeth carburization, harden...This work presented the characteristics of two gear teeth finishing methods, due to the properties of gear teeth surface layer obtained at the tooth working depth. These methods are: 1) the teeth carburization, hardening to a hardness of HRC 60-62 and then grinding, 2) the soft gear shaving as the final mechanical treatment and then carburizing and hardening to the hardness of HRC60-62. This work included the test results of the contact fatigue strength carried out on the circulating power system. The Wohler curves were plotted due to the obtained results, as the basis for the practical evaluation of the considered gear finishing methods. The parameters like volume distribution of the voids, content of the retained austenite, compressive residual stress value, but also the results of contact fatigue strength tests, are more favorable for the teeth shaving method than for the teeth grinding method.展开更多
To improve the transmission accuracy and stiffness of the ball cycloid reducer, the authors developed a novel cycloid ball reducer, which uses a full complement ball as its gear teeth. Ceramic balls are used to get be...To improve the transmission accuracy and stiffness of the ball cycloid reducer, the authors developed a novel cycloid ball reducer, which uses a full complement ball as its gear teeth. Ceramic balls are used to get better performance in severe working conditions. A simple synthesis method was also found to determine the raceway forms and compute the contact forces among the balls and raceways. The Contact Stress Analysis (CSA) computer program was used to optimize the design of the reducer. In this paper, the following topics are covered: (1) Study of the geometry of the raceways. (2) Analyses of the principal curvature of the raceways are also accomplished. In addition, the modification of the raceway is put forward. (3) The contact forces and the reducer efficiency are evaluated. (4) Study of the performance of ceramic balls used in the CBR. A reducer using the above design technique was tested and the performances show that the reducer has high precision and rigidity. An increase of more than 50 percent transmission power was realized in the new gearing.展开更多
Abundant system operation state information is included in the electrical signal of the hydraulic system motor.How to accurately extract and classify the operation information of electrical signal is the key to realiz...Abundant system operation state information is included in the electrical signal of the hydraulic system motor.How to accurately extract and classify the operation information of electrical signal is the key to realize the condition monitoring of hydraulic system.The early fault characteristics of hydraulic gear pump hidden in the motor current signal are weak and difficult to extract by traditional time-frequency analysis.Based on the correlation coefficient and artificial bee colony algorithm(ABC),the parameter optimization of variational mode decomposition(VMD)is realized in this paper.At the same time,the principle of maximum signal correlation coefficient and kurtosis value is adopted to determine the effective intrinsic mode function(IMF).Moreover,the permutation entropy(PE)and root mean square(RMS)of the effective IMF components are input into the deep belief network(DBN-DNN)as high-dimensional feature vectors.The operation state of gear pump is monitored.The results show that the weak characteristics of current signal of gear pump fault are accurately and stably extracted by this method.The running state of gear pump is monitored and the accuracy of gear fault diagnosis is improved.展开更多
An important concern in gear design is to reduce the dynamic load and noise of gear systems. It has been found that the noise generated from gearing is basically due to gearbox vibration excited by the dynamic load. S...An important concern in gear design is to reduce the dynamic load and noise of gear systems. It has been found that the noise generated from gearing is basically due to gearbox vibration excited by the dynamic load. Since one of the situations that demand high performance is the high rotational speeds, there is a need to understand the dynamic behavior of the gears at such speeds. Such knowledge would shed light on detrimental characteristics like dynamic loads and vibrations. An efficient way in performing studies on the dynamic behavior of gears is using computer aided analysis on numerical models. In this paper, a developed computer program is introduced to analyze dynamic behavior of spur gears with asymmetric teeth that have a potential use for higher performance in wind turbine gearboxes. This program can be used to compare conventional spur gears with symmetric teeth and spur gears with asymmetric teeth. By using this program, gear designers can design a gear pair and obtain results, e.g dynamic Load, transmitted torque, static transmission error, and frequency spectra of static transmission error etc., just by pressing a command button.展开更多
文摘This work presented the characteristics of two gear teeth finishing methods, due to the properties of gear teeth surface layer obtained at the tooth working depth. These methods are: 1) the teeth carburization, hardening to a hardness of HRC 60-62 and then grinding, 2) the soft gear shaving as the final mechanical treatment and then carburizing and hardening to the hardness of HRC60-62. This work included the test results of the contact fatigue strength carried out on the circulating power system. The Wohler curves were plotted due to the obtained results, as the basis for the practical evaluation of the considered gear finishing methods. The parameters like volume distribution of the voids, content of the retained austenite, compressive residual stress value, but also the results of contact fatigue strength tests, are more favorable for the teeth shaving method than for the teeth grinding method.
文摘To improve the transmission accuracy and stiffness of the ball cycloid reducer, the authors developed a novel cycloid ball reducer, which uses a full complement ball as its gear teeth. Ceramic balls are used to get better performance in severe working conditions. A simple synthesis method was also found to determine the raceway forms and compute the contact forces among the balls and raceways. The Contact Stress Analysis (CSA) computer program was used to optimize the design of the reducer. In this paper, the following topics are covered: (1) Study of the geometry of the raceways. (2) Analyses of the principal curvature of the raceways are also accomplished. In addition, the modification of the raceway is put forward. (3) The contact forces and the reducer efficiency are evaluated. (4) Study of the performance of ceramic balls used in the CBR. A reducer using the above design technique was tested and the performances show that the reducer has high precision and rigidity. An increase of more than 50 percent transmission power was realized in the new gearing.
基金National Natural Science Foundation of China(No.51675399)。
文摘Abundant system operation state information is included in the electrical signal of the hydraulic system motor.How to accurately extract and classify the operation information of electrical signal is the key to realize the condition monitoring of hydraulic system.The early fault characteristics of hydraulic gear pump hidden in the motor current signal are weak and difficult to extract by traditional time-frequency analysis.Based on the correlation coefficient and artificial bee colony algorithm(ABC),the parameter optimization of variational mode decomposition(VMD)is realized in this paper.At the same time,the principle of maximum signal correlation coefficient and kurtosis value is adopted to determine the effective intrinsic mode function(IMF).Moreover,the permutation entropy(PE)and root mean square(RMS)of the effective IMF components are input into the deep belief network(DBN-DNN)as high-dimensional feature vectors.The operation state of gear pump is monitored.The results show that the weak characteristics of current signal of gear pump fault are accurately and stably extracted by this method.The running state of gear pump is monitored and the accuracy of gear fault diagnosis is improved.
文摘An important concern in gear design is to reduce the dynamic load and noise of gear systems. It has been found that the noise generated from gearing is basically due to gearbox vibration excited by the dynamic load. Since one of the situations that demand high performance is the high rotational speeds, there is a need to understand the dynamic behavior of the gears at such speeds. Such knowledge would shed light on detrimental characteristics like dynamic loads and vibrations. An efficient way in performing studies on the dynamic behavior of gears is using computer aided analysis on numerical models. In this paper, a developed computer program is introduced to analyze dynamic behavior of spur gears with asymmetric teeth that have a potential use for higher performance in wind turbine gearboxes. This program can be used to compare conventional spur gears with symmetric teeth and spur gears with asymmetric teeth. By using this program, gear designers can design a gear pair and obtain results, e.g dynamic Load, transmitted torque, static transmission error, and frequency spectra of static transmission error etc., just by pressing a command button.
