Recent Patents on Mechanical Engineering - Volume 13, Issue 4, 2020

Background: Coal mining machines are the primary equipment used for the comprehensive mining of medium and thick coal seams. A shield machine is used to modify the geological structure of the soil, especially in urban subway tunnel engineering. The cutting and tunneling equipment have greatly improved the efficiency of coal seam mining and rock tunneling construction, but the consumption of picks in mining and tunneling is very high. Objective: In order to reduce the consumption of picks, it is necessary to obtain the change of temperature inside the pick in the process of cutting. Methods: This paper introduces a temperature measurement method to measure the temperature inside the conical and flat pick to provide a reference for the design and manufacture of picks. Results: The temperature measurement method used in flat and conical pick can obtain the temperature change inside the pick under the actual working condition, which has a considerable guiding significance to promote the development of coal mining. Conclusion: This study provides an important basis for the safety of mining operations and for prolonging the service life of picks. It has a strong innovation value and broad practicality.

Background: Traditional manipulator requires professionals to write control programs for specific job requirements so that the end-effector of the manipulator can work following the control instructions. However, the flexibility of the manipulator is not high under the control of off-line programming. With the diversification of the job requirements, the complexity of the work environment has gradually increased. Therefore, the relevant scholars focused their research on the automatic trajectory planning method of the manipulator. They used some algorithms to plan optimal trajectories for the manipulator to automatically avoid obstacles in the complex environment. Researches show that the hybrid optimal trajectory with parameter optimization such as time, energy and impact can be planned by automated programming under some constraint conditions. The trajectory planning is helpful to improve the automation and working efficiency of manipulators for the development of intelligent manufacturing. Objective: Providing references for researchers from related fields by reviewing recent advances of the manipulator trajectory planning. Methods: This paper reviews the latest patents and current representative articles related to the manipulator trajectory planning. The key methods of some references are introduced in several aspects of the algorithm, innovation and principle. Results: Researches on the manipulator trajectory planning in recent 10 years are reviewed. The differences between algorithms in latest patents and current articles are introduced and analyzed and the future developments and potential problems of the manipulator trajectory optimization are discussed. Conclusion: The manipulator trajectory planning reduces complicated operator and hard programming tasks, improving the intelligence of robots and the work efficiency. Current researches focus on collision- free, parameter-optimized and high-efficiency solution which can be used to solve the problem of the end-trajectory planning of the manipulator in the complicated space with obstacles. The aspects that need to be improved in the future include: algorithm reliability, operational security and intelligence, human-computer interaction, efficient simulation, and so on. More patents on manipulator trajectory planning should be invented.

Background: Electrical Discharge Machining (EDM) has widely been used in manufacturing high strength and high hardness of metal material due to the EDM process, which is free from mechanical force. The control system, a core of the EDM machine tool, plays a major role in manufacturing high strength and high hardness metal material in terms of machining efficiency and machining quality of the process of EDM. Thus, more and more attention has been paid to the current trends of the control system of the EDM machine tool. Objective: To meet the increasing requirements of machining quality and machining efficiency in the EDM process, the control system of the EDM machine tool is being improved continuously. Methods: This paper reviews current various representative patents related to the control system of the EDM machine tool. Results: By summarizing a large number of patents about the control system of the EDM machine tool, the parameter control system, the servo control system and the numerical control system of the EDM machine tool are analyzed, and the development trend of the EDM machine tool control system has been discussed. Conclusion: The optimization of the control system of the EDM machine tool is conducive to increasing machining efficiency and machining quality in the EDM process. More relevant patents will be invented in the future.

Background: Big data technology has been widely used in manufacturing supply chain management. However, traditional big data technology has some limitations, and it cannot achieve the continuous improvement of whole-process product quality tracing. Objective: The purpose of this study is to overcome the limitations by patents analysis and provide new big data technology and technical modes to make the continuous improvements of whole-process product quality tracing for achieving effective product lifecycle management based on big data technology. Methods: The research method, patent analysis, and comparative analysis are employed in this study to analyze product quality tracing in the manufacturing supply chain based on big data technology. Moreover, the procedure and steps of the new big data technology - Product Digital Twin (PDT), and its technical modes are designed by process design methods. Its key technologies are also analyzed and compared with traditional big data technology by the comparative study. Results: The research achieves the continuous improvements of whole-process product quality tracing based on new big data technology - PDT by patent analysis. The formation process and behavior of manufactured products in the realistic environment are simulated, monitored, diagnosed, predicted, and controlled. In this way, the high-efficient coordination in various stages of the product lifecycle is propelled fundamentally and the continuous improvements of the whole-process product quality tracing based on big data technology is analyzed. Conclusion: Three new technical modes based on big data technology are predicted for future researches and patents, namely, the immersive development mode integrating big data and the virtual reality technology, the knowledge-based multivariant coordinated development mode, and the lifecycle extended development model based on multi-domain interoperability.

Background: Nutation drive is being extensively investigated due to its ability to achieve a high reduction ratio with a compact structure and the potential for low vibration, high efficiency and design flexibility. However, many problems including the difficulty to process the inner bevel gear, less number of teeth in engagement and not being suitable for high-power transmission have restricted its development. Objective: The purpose of this paper is to analyze the contact strength of a patent about a new nutation drive developed based on meshing between two face gears, which has the advantages of both face gear and nutation drive, including large transmission ratio, large coincidence, small size, compact structure and strong bearing capacity. Methods: Based on the meshing principle and basic structure of the nutation face gear drive, the contact strength of nutation face gear transmission is analyzed by the Hertz contact analysis method and FEM method. Results: The maximum stress values of nutation face gear teeth are compared by two methods, which verify the accuracy of Hertz contact analytical method in calculating the contact strength of nutation face gear teeth. Furthermore, nine groups of three-dimensional models for the nutation face gear drive with a transmission ratio of 52 and different cutter parameters are established. Conclusion: The study analyzes the contact stress of fixed and rotary face gears in meshing with planetary face gears, and obtains the distribution law of contact stress and the influence of the number of teeth and parameters of the cutter on the load-carrying capacity.

Background: In some applications, the requirements of electro-hydraulic servo system are not only precise positioning, but also the speediness capability at which the actuator is operated. Objective: In order to enable the system to achieve rapid start and stop during the work process, reduce the vibration and impact caused by the change of the velocity, at the same time improve the positioning accuracy, and further strengthen the stability and the work efficiency of the system, it is necessary to perform the synergistic control between the position and the velocity of the electrohydraulic servo system. Methods: In order to achieve synergistic control between the position and the velocity, a control method of velocity feed-forward and position feedback is adopted. That is, based on the position control, the speed feed-forward is added to the outer loop as compensation. The position control adopts the PID controller, and the velocity control adopts the adaptive fuzzy neural network controller. At the same time, the position and velocity sensors are used for feedback, and the deviation signals between the position and the velocity obtained by superimposing the feedback are used as the final input of the control object, thereby controlling the whole system. Results: The control effect of the designed position / velocity synergistic controller is verified by simulation and experiment. The results show that the designed controller can effectively reduce the vibration and impact caused by the change of the velocity, and greatly improve the response velocity and the position accuracy of the system. Conclusion: The proposed method provides technical support for multi-objective synergistic control of the electro-hydraulic servo system, completes the requirements of multi-task operation, improves the positioning accuracy and response velocity of the electro-hydraulic servo system, and realizes the synergy between the position and the velocity. In this article, various patents have been discussed.

Background: Machining and metal coating of plastics are essential requirements as plastics are overtaking other engineering materials nowadays. Metallization improves product life as well as enhances its surface and mechanical properties. The machining (i.e., cutting, drilling, boring) of plastic parts with conventional processes is difficult as the dimensional accuracy and surface finish cannot be obtained from existing methods or/and needs multiple operations to acquire the surface finish needed. The coating of plastic materials is also a complex method using chemicals and electricity. An innovative method of coating and machining on plastic components has been demonstrated, which would be beneficial for potential researchers. A detailed analysis of previous patents and techniques has been performed based on which an advanced apparatus has been proposed. Objective: The objective of this study was to develop an apparatus based on non-conventional machining techniques. Moreover, the apparatus would be capable of plating metal layer on polymers using chemicals and fine metal particles. An in-depth analysis of previous patents used for the same application has been performed and based on the limitations of already existing techniques. Methods: An apparatus for machining and metal coating of polymers utilizes compressed air at high pressure mixed with chemical vapors. Before compression, the air is filtered to remove the impurities and moisture. Afterwards, heated chemical vapors are mixed with air in a specific proportion for machining of plastic parts. A jet of air and chemical vapours impinges on work material, which would perform machining in two steps. Initially, the chemical vapours would dissolve plastic material, which would instantly melt and starts flowing. Afterwards, the air jet would remove the excess plastic material due to high pressure. On the other hand, metallization can also be performed using different chemicals in proper proportion. Results: The apparatus makes it easy for machining and metalizing the ABS or plastic parts as the process is performed on one apparatus simultaneously one after the other. The high speed jet of acetone vapors has a greater tendency to perform various machining operations like cutting, drilling, boring of ABS parts. These vapours, when mixed with pressurized air, enhance the capability of machining the workpieces. And the metallization of plastic parts provides luster and surface finish to the workpiece. Conclusion: The present invention is to provide an apparatus for effectively plating or coating the machined workpieces. Moreover, the present work provides detailing of an apparatus for improving the mechanical strength, hardness and surface finish of the machined workpiece. In addition to this, the proposed apparatus is enabled to make strong bonding between metal particles and plastics.

Background: Mixer with excellent performance is the essential premise for high-quality mixture production to ensure uniformity. In the fields of food, pharmacy, powder metallurgy and machinery industry, materials mixing is an indispensable process. At present, the mixing efficiency and performance of the traditional mixer are very low, which has its own limitations, and it is difficult to ensure the quality of the mixture, which seriously affects the safety and reliability of the mixture products such as synthetic drugs, chemical reagents, cement, synthetic fiber, etc. Objective: In order to improve the mixing performance by improving the mixing uniformity, volume utilization, reducing the mixing time and mixing blind area, a novel planetary gear mixer for dry particle materials is designed. Its blades can rotate and the angle of attack can be changed at any time, which realizes the multi-degree of freedom movement of the blades. Methods: Firstly, the shortcomings of three kinds of traditional mixers are compared and analyzed; a novel planetary gear mixer for dry particles is proposed and its structural characteristics are described. Then, the transmission system and blade parameters of the mixer are designed and calculated, and the blade parameters of the mixers are optimized based on ADAMS and EDEM. Finally, the comparative simulation experiment between planetary gear mixers and SHR-10A mixers is carried out. The experiment is used to inquire on the mixing performance of the new planetary gear mixer. Results: The complementary cycloid was the ideal mixing trajectory of the blade. The most distinctive feature of this motion is that the attack angle of the blade can change in all directions. When the blade parameter p = 11, the Lacey index rises the fastest and the mixing degree is the largest, which indicates that the optimal mathematical model of the blade is ‘y2= 22x’. The comparison with SHR-10A mixer showed that spatial distribution of multi-degree of freedom blades in the new planetary gear mixer has strong dispersion effects on particles and better mixing performance. Conclusion: The planetary gear mixer for dry particle materials is a new type of mixer, which is composed of two sets of blades whose attack angle can be changed at any time. Convection and shear mixing dominate its mixing space, which is conducive to its rapid and full mixing, improving the mixing performance. The dry particle planetary gear mixer for dry particle materials has great developmental value and wide engineering application prospect. In this article, various patents have been discussed.