最新刊期
卷 47 ， 期 4 ， 2023
- 摘要：Aiming at the fatigue problem of the wheel edge reducer gear system of the drive axle of the loader, the dynamics simulation and fatigue life evaluation are carried out. Firstly, based on rigid-body dynamics and rigid-flexible coupling dynamics, the variation of the contact force between the solar wheel and the planetary wheel is analyzed, and compared with the theoretical calculation value of the contact force, the credibility of the model is verified. Then, the sun wheel is considered as a flexible body, and the stress-time history of the tooth root fatigue risk point is extracted. The peak-valley extraction and wavelet removal are carried out for the stress-time history. The influence of average stress is corrected by Goodman formula, and a one-dimensional stress spectrum is prepared. Finally, the crack initiation life of the tooth root is calculated and evaluated according to the linear fatigue damage accumulation criterion and compared with the experimental results. The results show that the crack initiation life of the solar wheel based on the rigid-flexible coupling dynamic model is 42 709 h, and the relative errors of the two experimental results are 1.5% and 3.7% respectively. The rationality of the evaluation method is verified, which provides a reference for the optimization and anti-fatigue design of the gear system.关键词：Load spectrum;Dynamics;Rigid-flexible coupling;Fatigue life
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发布时间：2023-05-04 - 摘要：The influence of Walker curve modification method on the tooth surface lubrication state of grease lubricated large internal meshing cylindrical spur gears is studied. According to the meshing law and engineering experience of internal meshing gear pairs, the tooth profile between pinion base circle and pitch circle is determined as an example, the tooth profile curve after modification is parameterized, the calculation model of tooth surface oil film thickness is established, and the lubrication state of modified tooth profile is numerically analyzed. The results show that the modification theory and experience of the same kind of small gears cannot be fully used for reference in the modification of large gears. The linearly increased modification amount cannot make the lubrication state of the tooth surface change linearly. Increasing the viscosity of grease can effectively improve the local poor lubrication caused by the defect of the modification curve.关键词：Internal meshing;Grease lubrication;Profile modification;Lubrication status
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发布时间：2023-05-04 - 摘要：Using the theory related to thermal coupling and heat transfer, the finite element software Abaqus is used to establish an orthogonal anisotropic C/SiC model of an automotive ventilated brake disc. Based on this model, different braking initial velocities, different braking pressures and different longitudinal expansion coefficients of the brake disc during emergency braking are simulated and analyzed. The results show that the temperature profile of the nodal unit of the brake disc exhibited "sawtooth" fluctuations under the effect of thermal coupling, and the thermal stresses mainly appeared in the middle region of the friction contact. The higher the braking pressure and initial speed during emergency braking are, the higher the temperature rise of the disc surface will be. However, the effect of different disc expansion coefficients on the maximum disc temperature is not significant.关键词：C/SiC;Brake disc;Thermodynamic coupling;ABAQUS;Temperature field
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发布时间：2023-05-04 - 摘要：Planetary herringbone gears are increasingly used in the high-power marine transmission system. In order to meet the noise requirements of transmission system of modern ships, the vibration reduction design of planetary herringbone gear transmission system is not only of practical value, but also of theoretical significance. Aiming at the planetary herringbone gear transmission in the power system of a ship, the analytical expression of the dynamic meshing force between the center gear and the planetary gear is established, and the coupling law between the number of teeth of planetary and center gear, the number of planetary gear and the vibration amplitude caused by the meshing frequency excitation is obtained. Based on the corresponding relationship between the vibration mode caused by time-varying meshing stiffness excitation and the natural vibration mode of the transmission system, and by reasonable design of basic parameters of planetary herringbone gear transmission, a phase tuning vibration reduction design method is proposed to suppress the torsional vibration of the system. The method has been verified to achieve the purpose of suppressing torsional resonance of the central member.关键词：Planetary herringbone gear;Phase tuning;Vibration mode;Vibration reduction design
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发布时间：2023-05-04 - 摘要：Gear-shaft-bearing systems are commonly used in transmission mechanisms. When there are fit clearances between the bearing outer ring and the bearing housing, complex vibration responses will be generated, which makes the recognition of operating status more difficult. Thus, a 36 DOFs model of the gear-shaft-bearing system with bearing fit clearances is established. In this model, the gear pair system and the bearing system are combined, the collision force and friction force caused by the fit clearance are considered, which are calculated by the nonlinear contact in Hertz theory and Coulomb friction model. The results show that when there are fit clearances on the bearing, the amplitude modulation of the bearing outer raceway to the system time-domain response is exacerbated. The larger the fit clearance is, the more serious the amplitude modulation will be. Due to the increase in the number of attenuations, the multiple harmonic components of gear pairs and bearings are generated on the spectrum. As the bearing fit clearance is increased, the higher multiple harmonic components will be generated. Finally, the established model and the analysis of the results are verified by experiments.关键词：Gear-shaft-bearing system;Fit clearance;Collision and friction;Vibration response
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发布时间：2023-05-04 - 摘要：Aiming at the problems that the pipeline robot is difficult to turn and has poor moving stability in the variable diameter pipeline, an adaptive oil and gas pipeline robot is studied; adopting a variable-diameter two-track and one-roller-supported moving mechanism, the stable movement of the robot in the pipeline is ensured. Theoretical research on the passage of oil and gas pipeline robots in the pipeline is conducted, and the size of the robot is determined; the dynamics of the robot's turning performance is studied by Adams. The simulation results show that the robot can successfully complete the turning movement in the 600 mm pipeline, and therefore it is determined that the torque provided by the motor should be greater than 90 N
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发布时间：2023-05-04 - 摘要：The wheel reducer is one of important transmission structures of heavy or new energy vehicles for increased torque and reduces speed. The gearbox mainly carries the internal load from gear transmission and the external load from frame connection. The reasonable design and strength performance of the gearbox are important guarantees for the smooth operation of the wheel reducer. Based on the three-dimensional geometric structure of the gearbox and the finite element analysis method, a structural strength analysis method integrating "model-strength evaluation-running" is established and the structural strength of the gearbox is investigated comprehensively. The results show that the box under the load and strength evaluation criteria of combined calculation has sufficient design strength and stiffness, which can support the smooth operation of the infield transmission system and resist the deformation caused by external load. The distributed contact area of the joint surface of gearboxes is ensured by the sufficient distribution and strength of bolts, and no oil leakage occurs in the gearbox. The operational experiment result of gearboxes is in agreement with the above theoretical analysis. The proposed structural strength analysis method provides a technical basis for the structural design of the gearbox.关键词：Wheel reducer;Gearbox structure;Fatigue strength;Operational analysis
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发布时间：2023-05-04
Theory·Research
- 摘要：The aircraft door must be smoothly linked with the outer surface of the fuselage and realize the sealing function of the inner and outer boundaries of the fuselage at the same time. The normal opening and closing can be realized only when the position and posture of the door relative to the fuselage are corrected. In view of the fact that the opening branch chain of the existing lifting arm 4R mechanism linked in series with the large hinge arm mechanism cannot adjust the position and attitude of the aircraft door in all directions, a new aircraft door opening branch chain is proposed, which uses the plane-symmetric Bricard mechanism instead of the 4R mechanism, and forms a three branch chain aircraft door opening parallel mechanism with the parallel rod mechanism 2-S-S branch chain. Based on the orientation feature set theory of parallel mechanism, the azimuth feature set analysis of door opening mechanism under different modes is carried out. It is verified that the 6R mode, 4R mode and mode switching of serial large hinge arm surface symmetrical Bricard mechanism can realize the lifting of aircraft door and the adjustment of omnidirectional position and attitude. The orientation feature set of the mechanism reveals that the lifting, adjustment and rotation motion of the opening mechanism has a degree of freedom, and three motion modes with different independent elements are selected：6R lifting, spherical 4R adjustment movement and large hinge arm rotation during door opening. When the Bricard mechanism is embedded, the aircraft door can be coupled and adjusted in three directions, which provides a new idea for the design of aircraft door.关键词：Aircraft door opening mechanism;Plane-symmetric Bricard linkage;Multimode motion;Position and orientation characteristics
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发布时间：2023-05-04 - 摘要：The finite position method is applied to the complete balance design and partial balance optimization of swing force of a new spatial 1T1R parallel mechanism. Firstly, according to the topology design theory of parallel mechanism, a new type of translation rotation (1T1R) parallel mechanism is designed, and the topology and position analysis are carried out. Secondly, divide the tree, determine the connecting branch component, and finally calculate the total mass moment of the mechanism by obtaining the mass moment of the two sub kinematic chains (SKC) contained in the mechanism. Then, according to the mass moment balance condition, the complete balance equations of pendulum force are derived, the counterweight parameters of each branch member are obtained, and the complete balance effect is verified. Finally, considering the practical principle, further study the balance optimization of the pendulum force part, and use the genetic algorithm to obtain the optimal counterweight mass and counterweight position, and compare the balance before and after. The calculation shows that the fluctuation of the center of mass trajectory of the mechanism in the X, Y and Z directions is reduced by 55.38%, 26.17% and 86.29% respectively, and the fluctuation of the pendulum force in the X, Y and Z directions is reduced by 58.39%, 67.11% and 39.19% respectively.关键词：Parallel mechanism;Topology analysis;Finite position method;Pendulum dynamic balance;Total mass moment
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发布时间：2023-05-04 - 摘要：In order to make the internal leakage calculation and volume efficiency evaluation of gear pumps or motors more realistic, based on the deformation law of elastomers and the consistency requirements of the torsion resistance of the shaft, the servo clearance and shaft radius with linear change of addendum radius is proposed, and then a corresponding servo model for calculating inner leakage is derived. Finally, the influence of gear width-diameter ratio on pump volume efficiency is analyzed. All results show that the maximum of gear shape factors is beneficial to the maximum of volume factors and the lightweight of gears; the maximum of addendum coefficients of gears without undercut cannot achieve higher volumetric efficiency; the larger the width-diameter ratio is, the higher the volume efficiency is, and the better the lightweight is, which is opposite to the conclusion under fixed clearance and shaft radius. It is concluded that the servo model for calculating the inner leakage is simple and reliable.关键词：Gear pump or motor;Servo clearance;Addendum radius;Shape factor;Volume factor;Lightweight
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发布时间：2023-05-04 - 摘要：In the calculation of mobility of the mechanism using the modified Grübler-Kutzbach's formula of mechanism mobility, the common constraint of the mechanism has to be solved. In order to obtain the common constraint of the mechanism with a simpler method and on the basis of defining the common constraint of the mechanism, the coordinate direction of the mechanism without common constraint is obtained according to the mobility of kinematic pair and the constraint direction of the kinematic pair whose absolute motion is not zero, and then the common constraint of the mechanism is determined in other coordinate direction. The total number of coordinate directions with and without the common constraint of the mechanism is 6. The common constraint of the mechanism is equal to the number of coordinate directions with common constraint. This method does not need the screw theory to solve the common constraints of the mechanism, which is convenient for engineering and technical personnel to solve the common constraints of the mechanism. It is also convenient for the modified Grübler-Kutzbach's formula of the mechanism mobility to be popularized and applied in engineering and technical personnel.关键词：Mechanism;Mobility;Common constraint;Mobility of kinematic pair;Absolute motion of kinematic pair;Coordinate direction
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发布时间：2023-05-04 - 摘要：Aiming at the ankle rehabilitation and training of stroke patients, an ankle rehabilitation mechanism with 3R1T sports performance is proposed. The screw theory is used to analyze the degree of freedom, the closed vector method is used to solve the inverse position solution, and Adams is used to simulate the kinematics of the hybrid mechanism. The maximum rotation angle error of the mechanism during dorsiflexion and toe flexion is calculated. The results show that under the displacement-restriction device, the mechanism can complete the rehabilitation movement and vertical joint traction movement required by patients within the safe range of ankle movement.关键词：Rehabilitation mechanism;Ankle joint;Hybrid mechanism;Kinematics;Displacement-restriction device
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发布时间：2023-05-04 - 摘要：Taking a new type of prefabricated building wall panel installation machine as the research object, the mechanism configuration and specific implementation are analyzed, the kinematic and dynamic mathematical models of the boom landing mechanism are established, and the functional relationship between the maximum load of the cylinder and the scale parameters is solved. Taking the size parameters of each component of the boom landing mechanism as the design variables, taking the minimum maximum load of the boom cylinder during the boom lifting process as the objective function, and taking the overall machine layout, mechanism singularity, geometric constraints and other constraints as the constraints, the boom is established. The scale optimization model of the landing mechanism, based on the composite shape method and iterative calculation through Matlab software, the optimal scale parameters of each component of the boom lift chain are obtained, and the maximum load of the boom lift cylinder is reduced by about 11%, effectively improving the dynamic performance of the mechanism. Based on Creo software, a virtual prototype of the prefabricated building wall panel installation machine before and after optimization is established, and dynamic simulation analysis is performed to verify the correctness of the scale optimization model. This research will be used for prefabricated building wall panel installation and provides a basis for improving the performance of the machine.关键词：Wall panel installation device;Closed vector method;Dimensional optimization;Complex method;Dynamic simulation
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发布时间：2023-05-04 - 摘要：A novel hybrid dual-platform staggered hexapod robot based on R&(2-UPU/2-RPR) hybrid mechanism is proposed, and the structure of the robot is designed. The hexapod robot relies on the mutual dislocation of the upper and lower platforms of a 2-UPU/2-RPR parallel mechanism to generate the walking action. The parallel mechanism is also used as a body connecting two groups of three legs, so that the robot can achieve “3+3” gait walking with less driving. The body of the hexapod robot is connected in series with the loading platform by a relative rotation structure, which can realize 360° flexible turning with zero radius. The inverse position solution of the parallel mechanism is obtained based on the RPY transformation matrix. The maximum step length, the maximum zero radius turning angle of a single turn in an intermittent period of the hexapod robot and the trajectory curve of the hexapod robot are obtained by analyzing the mutual interference constraints of the legs and driving constraints of the hexapod robot. The gait of the hexapod robot walking on flat ground and climbing steps is analyzed. Finite element analysis results on its load capacity show that the hexapod robot can replace the porter and has a wide range of potential applications.关键词：Hexapod robot;R&(2-UPU/2-RPR) hybrid mechanism;Gait analysis;Trajectory planning;Loading capacity
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发布时间：2023-05-04
Design· Calculation
- 摘要：Ingot processing affects gear fatigue performance, which remains to be studied and becomes an important bottleneck problem limiting gear anti-fatigue design and cost saving. Surface integrity measurements of 18CrNiMo7-6 gears with mold ingots, continuous casting billet and electro-slag ingots are carried out, and tooth root residual stress, surface roughness and hardness gradient of these gears are studied. Based on GB/T 14230—2021 Test method of tooth bending strength for gear load capacity, gear bending fatigue tests are conducted with the staircase method. The bending fatigue limits under different reliabilities are obtained, and the influence of ingot processing on the bending fatigue performance is explored. The gear bending fatigue limit is also evaluated with the effective Locati method, and is compared with results of the lifting method. It provides some references for fundamental data construction of gear fatigue and anti-fatigue design in China.关键词：Gear bending fatigue;Ingot processing;Staircase method;Locati method
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发布时间：2023-05-04 - 摘要：The optimization analysis of gears in a hybrid transmission is carried out using the micro-modification module in the simulation platform of system analysis software MASTA，aiming at the vibration and noise problems of gear meshing in hybrid transmission. By comparing the transmission error between gears before and after modification and the contact stress nephogram of the tooth surface, the effectiveness of micro-modification based on system analysis software MASTA is verified, which provides a reliable theoretical basis for actual modification. The analysis results show that the transmission error of the gear is obviously reduced after micro-modification, and the contact stress nephogram of the tooth surface has been improved to a great extent, which plays an active role in reducing the vibration and noise of the gear. Finally, the data collection and comparative analysis of vibration and noise of gears in transmission are carried out. The results show that the corresponding box vibration acceleration and gear noise will be significantly improved after the micro-modification of the gear pair.关键词：Hybrid transmission;Vibration and noise;Micro-modification;Transmission error;Contact stress nephogram of tooth surfaces
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发布时间：2023-05-04 - 摘要：When a high speed magnetic field modulated gear is working, eddy current loss and wind friction loss will occur in permanent magnet and magnet block. In order to study the flow field and temperature field in small gaps of high speed magnetic gears, a magnetic gear with internal rotor speed of 16 500 r/min and external rotor speed of -3 000 r/min is taken as the research object. For the small gap of a magnetic gear, the flow field and temperature field calculation is carried out using computational fluid dynamics. It takes into account both natural convection and forced air cooling heat transfer. The results show that only by natural convection heat transfer, the permanent magnet will lose magnetism due to high temperature. When forced air cooling is introduced, the temperature of permanent magnet can be controlled within 402.98 K（129.83 ℃）. The convective heat transfer coefficient curve along the axial distribution is given when the axial wind speed is 15～30 m/s. The research results provide reference for thermal design of magnetic field modulated gears.关键词：Magnetic field modulated gear;Computational fluid dynamics;Flow field;Temperature field;Thermal design
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发布时间：2023-05-04 - 摘要：High-speed deep groove ball bearings are widely used in drive motors and reducers of new energy vehicles, and the requirements of bearing accuracy, life and reliability are getting higher and higher with development of new energy vehicles technology. One of the main failures of high speed ball bearings is cage fractures. In this study, the relationship between the cage stress and the strain is systematically analyzed, the centrifugal force of the cage itself is indicated as the biggest influencing factor, and key points of cage design are proposed. The simulation results are verified by Abaqus and CABA3D; the bench test and customer installation testing are verified. The research is important for cage design of high speed ball bearings and improving bearing reliability.关键词：High speed deep groove ball bearing;Cage design;Centrifugal force;Fracture
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发布时间：2023-05-04 - 摘要：The cable-driven parallel robot is a special flexible mechanism in parallel mechanism, the end-effector of which is driven by cables instead of rigid rods. It integrates the advantages of flexible robots and parallel robots. A three-degree-of-freedom (3-DOF) under-constrained parallel robot with variable cable mast heights is investigated in this study. The inverse kinematics model of the robot is established by using the vector closed-loop principle. The forward kinematics model of the robot is derived according to cable lengths. The dynamics model of the robot is established based on the Lagrange formula. The static equilibrium workspace (SEW) of the robot is studied using the Monte-Carlo method. Given the motion trajectory of the end-effector, the expected three cable lengths are obtained through the inverse kinematics model of the robot. Taking the expected three cable lengths as the experimental input, the experimental curves of cable lengths and cable tensions as well as the forward kinematics trajectory of the robot are obtained. The experimental results validate the correctness of the forward and inverse kinematics models and the dynamics model of the robot, as well as the effectiveness of the SEW.关键词：Cable-driven parallel robot;Variable cable mast height;Forward and inverse kinematics modeling;Dynamics modeling;Static equilibrium workspace
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发布时间：2023-05-04 - 摘要：The coiled tubing injector head is the core component of the coiled tubing oil and gas well operation equipment, which directly determines the coiled tubing operation capability, and its chain drive system pulls the coiled tubing in or out the wellbore. However, the unsteady chain drive and the wear between the chain and sprocket are common problems which are the main factors leading to slipping, pipe sliding and bites of coiled tubing in engineering practice. Based on the standard roller chain and sprocket, the mechanical model of the engagement contact between the injector head chain and the sprocket teeth is established to analyze the influence of chain tension force, chain tension angle and chain pitch on the position of contact points and tooth surface support reaction force, and the accuracy of the contact mechanical model is verified by Ansys simulation which lays a theoretical foundation for the design and safety of the injector. The research shows that when the tension force of the chain increases and the loosening force remains unchanged, the engaging-in position of the chain on the tension side is basically unchanged, the reaction force of the tooth surface support increases, and the engaging-out position of the chain rollers is close to the bottom of the sprocket teeth. However, when the tension force approaches the loosening force, there is a sudden increase in the support reaction force of the engaging-out contact position. The increase of the angle between the tension side and the vertical direction of the chain has little effect on the engaging-in position and the tooth surface support reaction force, the engaging-out position of the chain rollers is close to the bottom of the sprocket teeth. The engaging in and out points of the chain are respectively away from the direction of the bottom of the sprocket teeth and the contact position is improved when the chain is extended.关键词：Coiled tubing;Injector head;Chain drive;Engagemen;Ansys
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发布时间：2023-05-04
Test·Analysis
- 摘要：For the purpose of adjusting the calculation of the contact pattern of real hypoid gears, the double third-power spline surface is used for fitting tooth surfaces of pinions and gears accurately according to the measurement results of the gear surface. Based on the two-dimension golden section method for increasing the density of gear grid mesh points, the contact analysis algorithm for discrete real gear surface is established to carry out the contact information of real gear surface and adjust parameters of contact patterns, which is applied for adjusting of machining-tool settings conveniently. In the end, a hypoid gear pair of automobile driving axles is used to verify the feasibility and correctness of the proposed algorithm by rolling tests, which shows that the contact pattern by discrete tooth contact analysis is consistent with the real rolling test.关键词：Hypoid gear;Contact pattern;Tooth surface refinement;Interference
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发布时间：2023-05-04 - 摘要：The second edition of ISO 1328-2 was released in 2020, which adjusted the scope of application and modified the evaluation system of accuracy level to distinguish it from ISO 1328-1. In order to better understand and apply the gear accuracy standard, the author starts with the change of the standard name and calculation rules of the deviation allowable values, and analyzes the relationship between the differences of each deviation item and the dependent variables in the first and second editions of ISO 1328-1 with the help of the modulus mn, the diameter d of the dividing circle and other variables. At the same time, the author analyzes and compares the new and old editions of ISO 1328-2 in the scope of application, tolerance classification and deviation items and differences in the determination methods of allowable deviation values. The results show that the first and second editions are quite different and should be paid attention to.关键词：Gear;Tolerance classification;Standard;Analysis
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发布时间：2023-05-04 - 摘要：In order to achieve high comprehensive performance for external gear pumps, a tooth profile construction method with working pressure angles greater than non-working pressure angles is invented. From parameters analysis of tooth profiles without undercut and displacement, the analytical expressions of pump performance coefficients such as lightweight, flow ripple and trapped-oil phenomenon on working pressure angles are derived; then from the minimum allowable value of the addendumarc angle, a one-dimensional iterative model for determining non-working pressure angle is derived. All results show that the double pressure angles construction method not only eliminates the undercut phenomenon, but also adopts the standard machining; the greater the working pressure angle is, the better the performance of lightweight, oil trapping and tooth root bending resistance will be, but the worse the quality of the flow pulsation will become; the larger the working pressure angle is, the larger the radius of curvature of the tooth profile is, the smaller the sliding coefficient and contact stress of the tooth surface are, the smaller the wear of the gear teeth will be and the longer the service life will become; the higher the addendum height coefficient is, the better the flow pulsation quality is, the worse the oil trapping performance is, and there will be little impact on the lightweight performance. The non-working pressure angle is determined by the working pressure angle and the allowable lower limit of the addendum arc angle and this method is simple and reliable. It is concluded that the tooth profile construction method with working pressure angle greater than non-working pressure angle can achieve high comprehensive performance for external gear pumps.关键词：Gear pump;Double pressure angles;Tooth profile construction;No undercut and no displacement;Lightweight;Flow ripple;Trapped-oil performance
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发布时间：2023-05-04 - 摘要：The pipeline plays an important role in the transportation of energy, and its safe, reasonable and stable operation is of great significance. This study takes DN250-350 mm oil and gas pipelines as the main application scenario, and plans to design a crawler-type pipeline inspection and repair robots that use a screw nut reducing mechanism to achieve diameter reduction to achieve self-adaptive purposes. The crawler-type pipeline inspection and repair robot can be divided into a drive unit, a detection unit, a connection unit and an isolation repair unit. When the length of the constituent unit of the robot is less than 452.88 mm, it can pass through the elbow from the analysis of geometric constraints. The speed equation of the robot can be obtained by analyzing the motion state of the robot during the running process by the coordinate transformation method. The crawler robot moves more smoothly when passing through the bend with the 3-track differential characteristic. By means of simulation analysis and experimental verification, the passing ability of the elbow is verified. The research on the passing ability of the crawler-type pipeline inspection and repair robot can provide some references for the stable inspection, emergency security and treatment of oil and gas pipelines.关键词：Oil and gas pipelines;Crawler type;Inspection and repair;Elbow passing performance;Adams simulation analysis
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发布时间：2023-05-04 - 摘要：Aiming at the deformation of thin plate gears, the main reasons are analyzed as follows: large residual stress after machining, large thermal stress and structural stress during heat treatment, effects of grinding heat, poor rigidity of parts during grinding, large flatness error of locating surface, unreasonable arrangement of finishing process and unstable clamping. Combined with the actual processing, several improvement measures are put forward, such as optimizing the structure of heat treated parts, reducing the influence of machining residual stress, reducing the flatness error of locating surface, optimizing the finishing process and improving clamping stability. It is verified that these improvement measures have positive impact and ensure the accuracy of parts, which provides technical reference for similar thin plate gear parts.关键词：Thin plate gear;Heat treatment;Deformation;Thickness;Structure;Clamping;Grinding
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发布时间：2023-05-04
Development·Application
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