In modern mechanical systems, the trend toward higher speeds and heavier loads has made the vibration of gear transmission systems under elastohydrodynamic lubrication a critical research topic. The presence of an oil film alters both the meshing stiffness and the friction coefficient at the tooth surfaces, profoundly affecting the dynamic response of spur gears. As… Read more: Study on Vibration Characteristics Prediction of Spur Gears with Elastohydrodynamic Lubrication

I have focused my investigation on the precision plastic forming of a driven spiral bevel gear used in an automotive drive axle. A spiral bevel gear has curved teeth, a gradual contact pattern, high load capacity, and smooth transmission characteristics. Compared with a straight bevel gear, the spiral bevel gear is much better at satisfying… Read more: Two-Way Precision Forming of Spiral Bevel Gears

I have focused my research on the relationship between the transmission error of a hypoid bevel gear pair and the noise, vibration, and harshness performance of an automotive rear-axle main reducer. A hypoid bevel gear is one of the most important transmission components in a rear-drive vehicle. It reduces speed, increases torque, and changes the… Read more: Hypoid Bevel Gear Transmission Error and Main Reducer NVH

I investigated a longitudinal cracking failure that appeared in a finished 22CrMoH pinion gear after the pinion gear had completed machining, carburizing, quenching, low-temperature tempering, straightening, cleaning, and either packaging or assembly preparation. In my evaluation, the crack was not associated with gross chemical nonconformity, macroscopic nonmetallic inclusions, or obvious surface decarburization. Instead, the evidence… Read more: Quench Cracking in 22CrMoH Pinion Gears

In the realm of high-power transmission systems, the precise modeling of spiral bevel gears is paramount for advanced design, dynamic simulation, and contact analysis. My focus here is to detail a methodology for constructing an exact 3D digital model of a spiral bevel gear, specifically the large wheel (gear), by rigorously emulating the kinematics of… Read more: A Comprehensive Guide to Accurate 3D Modeling of Spiral Bevel Gears via NC Machining Kinematics

In my research on electric power steering (EPS) systems, worm gears play a pivotal role in transferring torque from the electric motor to the steering rack while providing the necessary reduction ratio. The efficiency of these worm gears directly impacts the overall energy consumption of the vehicle, especially under low‑speed high‑torque maneuvers common in urban… Read more: Efficiency Optimization of Worm Gears in Automotive Steering Systems

In the realm of power transmission for heavy-duty applications, the manufacturing of spiral bevel gears represents a pinnacle of precision engineering. Among the various established gear cutting systems, one that has consistently demonstrated superior performance, particularly for customized or small-batch production, is the system developed by Klingelnberg, based on the Cyclo-Palloid principle. This epicycloidal gear… Read more: Advanced Gear Cutting with the Klingelnberg Spiral Bevel Gear System

I treat the shifted helical gear transmission system as a coupled mechanical system in which geometric profile shift, time-varying mesh stiffness, dynamic mesh force, dynamic transmission error, and axial vibration acceleration are strongly connected. My objective is to formulate an analytical and dynamic framework that can describe how profile shift changes the behavior of a… Read more: Dynamic Characteristics and Optimization of Shifted Helical Gear Transmission Systems

Herringbone gears are widely used in marine propulsion, aerospace, and other large power equipment owing to their high load-carrying capacity and small axial thrust. However, the centering of tooth flanks on the two sides of a herringbone gear relative to the central symmetry plane directly affects the uniformity of contact load distribution, which can cause… Read more: Measurement and Evaluation of Symmetry of Herringbone Gears Oriented to Performance

I investigated a recurring surface-quality problem in a 20CrMnTi steel gear forging line. The problem appeared as small, approximately circular point defects on the surface of gear forging blanks. I observed these defects both on as-forged blanks and after turning. Because a gear forging is expected to have a clean, homogeneous surface before machining, the… Read more: 20CrMnTi Gear Forging Defects

In mechanical transmission systems, spur gears are fundamental components that often operate under heavy loads. In such conditions, the lubrication supply may become insufficient, leading to starved or dry friction states. This can result in severe wear and temperature rise on the gear tooth surfaces, potentially causing failures like scuffing, plastic deformation, or even catastrophic… Read more: Numerical Simulation of Dry Friction Wear in Spur Gears

In the field of mechanical power transmission, spur gears are among the most fundamental and widely used components due to their simplicity and efficiency. However, the inherent dynamics of gear meshing, such as transmission error, vibration, and noise, pose significant challenges to high-performance applications. Gear modification, which involves intentional deviations from the ideal tooth profile,… Read more: A Novel Design Methodology for Compound Modification of Spur Gears

As an engineer and researcher deeply involved in the field of precision machinery, I have observed the rapid growth of industrial robotics globally, particularly in China, where it is regarded as a strategic sector under initiatives like “Made in China 2025.” The RV reducer, a critical component in robotic joints, remains a bottleneck for domestic… Read more: Key Challenges in Domestic Mass Production of RV Reducers

In modern mechanical transmission systems, hyperboloid gears play a critical role due to their ability to transmit motion between non-parallel and non-intersecting shafts with high efficiency and compact design. The quality of tooth surface machining directly impacts the performance, vibration, noise, and service life of hyperboloid gear pairs. Achieving precise tooth profile geometry is essential… Read more: Precision Control of Hyperboloid Gear Tooth Profile via Coordinate Measurement

I investigated a face gear transmission system because a face gear offers compact structure, high load capacity, favorable torque splitting, and large transmission ratio. These advantages make the face gear attractive for high-speed and heavy-load applications such as aviation transmission systems and heavy vehicles. However, the same severe operating conditions that make the face gear… Read more: Laser Cladding and Grinding of Face Gear Tooth Surfaces

In the realm of precision mechanical component manufacturing, the production of internal profiles such as uniformly distributed polygonal internal squares (e.g., hex sockets), multiple (or single) keyways, and internal splines with missing teeth presents a significant challenge. Traditionally, these features are machined using conventional slotting machines. While functional, this method suffers from inherent limitations that… Read more: Precision Machining of Internal Profiles with CNC Gear Shaping Technology

In the automotive industry, the drive axle is a critical powertrain component, and within it, the bevel gear pair plays a pivotal role in transmitting torque and motion. The performance of bevel gears directly impacts the overall efficiency, noise, vibration, and harshness (NVH) characteristics of the transmission system. One key parameter influencing bevel gear performance… Read more: Finite Element Modeling and Analysis for Misalignments of Bevel Gears in Drive Axles

In this work I investigate the dynamic excitation behavior of automotive differential straight bevel gears. The focus is on the numerical simulation of both internal and external excitation sources because straight bevel gears operate under strongly time-varying contact conditions, manufacturing deviations, engine torque fluctuations, and road-induced disturbances. My objective is to build a consistent modeling… Read more: Excitation in Straight Bevel Gears

The design and manufacturing of power transmission components demand precision and efficiency, and among these, herringbone gears hold a particularly significant position. As a variant of helical gears, herringbone gears feature a unique double-helical structure that effectively cancels out the detrimental axial thrust forces inherent in single helical gears. This characteristic makes them indispensable in… Read more: Parametric Modeling System for Herringbone Gears Based on SolidWorks Secondary Development

I approach the design of a screw gear transmission as a networked engineering service rather than as a manual calculation exercise. In my use of the term, a screw gear is the threaded mechanical pair formed by a screw and a nut, and its primary purpose is to transform rotational motion into linear motion. I… Read more: Networked Screw Gear Design

In my research, I study how manufacturing errors influence the transmission accuracy of a miter gear drive. The miter gear in this work is a double-helical gear pair whose left and right tooth flanks are generated as opposite-handed helices. This configuration combines the smoothness of helical action with a natural cancellation of axial force, so… Read more: Miter Gear Transmission Accuracy with Manufacturing Errors

In my extensive experience with mechanical component failures, I have encountered numerous cases of gear shafts exhibiting abnormal cracking. These gear shafts, often used in heavy-duty applications, have presented significant challenges due to sudden failures after assembly, load testing, or even post-shipment. This analysis delves into the root causes of such cracking in large-sized gear… Read more: Failure Analysis of Gear Shaft Cracking

In modern mechanical engineering, the design and manufacture of critical transmission components demand a high degree of precision and reliability. Among these, the screw gear assembly, particularly within indexing heads and gearboxes, is fundamental for converting motion and torque with high reduction ratios and self-locking capability. The performance of the entire system is heavily dependent… Read more: Optimization of Screw Gear Box Design and Performance

In the realm of mechanical engineering, the accurate measurement and calculation of gears are paramount for ensuring the reliability and efficiency of machinery. As an engineer with extensive experience in gear design and analysis, I have often encountered the challenge of reverse-engineering spur and pinion gears from foreign equipment. These gears, particularly involute cylindrical spur… Read more: Spur and Pinion Gear Plotting and Calculation

In this study, I investigate the elastohydrodynamic lubrication (EHL) problem for spur gears, considering transient effects, temperature fields within the oil film, and longitudinal surface roughness on gear teeth. The load is borne by either single or double teeth, based on a simplified load spectrum from actual gear operation. Using the multigrid method for pressure… Read more: Transient Micro-Thermoelastohydrodynamic Lubrication Analysis of Spur Gears

In the realm of power transmission and mechanical systems, the gear shaft stands as a critical component, responsible for transmitting torque and rotation while supporting significant bending and torsional loads. The performance and longevity of the entire drivetrain are intimately tied to the reliability of the gear shaft. A primary failure mode for these components… Read more: Optimizing Surface Hardening of 40CrNiMo Gear Shafts

The reliable and quiet operation of heavy-duty gear reducers is paramount in industrial applications such as construction hoists. A primary source of vibration and noise in these systems is non-uniform load distribution across the tooth face of the gears, a phenomenon known as bias loading. This uneven loading often stems from a combination of elastic… Read more: Comprehensive Load Distribution Optimization for Helical Gears in Heavy-Duty Reducers

In automotive electric power steering (EPS) systems, the worm gear pair is the core transmission component that directly determines steering feel, energy consumption, and durability. My research focuses on systematically analyzing the influence of surface treatments, material combinations, and lubrication on worm gear efficiency, with a specific emphasis on lightweight design. This paper presents experimental… Read more: Analysis of Worm Gear Transmission Efficiency Factors in Automotive Steering System

In the realm of power transmission systems, bevel gears play a pivotal role, especially in applications like electric tools where compact design and efficient torque transfer are essential. As a practitioner in powder metallurgy, I have observed the growing adoption of powder metallurgy bevel gears due to their cost-effectiveness and suitability for mass production. However,… Read more: High-Strength Powder Metallurgy Bevel Gears: A Comprehensive Manufacturing Guide

I propose a practical method for grinding face gears on a general cylindrical internal gear grinding machine. My motivation is straightforward: face gears offer compact transmission layouts, convenient mounting and adjustment, and large transmission ratios, yet their precision manufacturing still depends heavily on specialized face gear grinding machines. That dependence raises tooling cost, reduces process… Read more: Grinding Face Gears on a Cylindrical Internal Gear Grinding Machine

In this work, I present a comprehensive finite element simulation of the surface quenching process for a 20CrMoH spur gear using ANSYS. The primary objective is to examine the transient temperature field, thermal stress, and thermal deformation that arise when the spur gear is rapidly cooled in two distinct quenching media: stationary oil and stationary… Read more: Finite Element Simulation of Spur Gear Quenching

In the field of mechanical power transmission, screw gears, commonly referred to as worm gears, play a critical role in applications requiring high reduction ratios and compact design. However, mismatched screw gears—where the worm and worm wheel are not conjugate pairs—often face severe failure issues due to abnormal stress concentrations and wear. This article presents… Read more: Finite Element Analysis of Mismatched Screw Gears in Different Meshing Positions

The demand for high-performance power transmission systems, particularly in sectors like aerospace, automotive, and heavy machinery, continuously pushes the boundaries of gear design. Among various gear types, the spiral bevel gear stands out for its ability to transmit power smoothly and efficiently between intersecting shafts, typically at a right angle. Its curved teeth allow for… Read more: High Contact Ratio Negative Transmission Spiral Bevel Gears: An Integrated Design and Performance Analysis

I have focused my research on the relationship between the transmission error of hypoid bevel gears and the noise, vibration, and harshness performance of the main reducer. Hypoid bevel gears are critical transmission components in the rear axle main reducer of rear-wheel-drive vehicles. They serve to reduce speed, increase torque, and change the direction of… Read more: Transmission Error of Hypoid Bevel Gears and Main Reducer NVH

The study of vibration and noise in power transmission systems is critical for enhancing operational reliability, structural integrity, and acoustic comfort, particularly in demanding applications such as marine propulsion. Among various gear types, the herringbone gear stands out due to its inherent ability to cancel axial forces, leading to high load capacity and smooth operation.… Read more: Analysis of Vibration and Noise in Herringbone Gear Reducers

The pursuit of high-efficiency and high-precision manufacturing for small module straight bevel gears is a persistent theme in modern gear production. Traditional methods, such as gear planing, often suffer from inherent limitations in cycle times due to their intermittent, single-tooth indexing nature. This article details a research and development effort focused on implementing a continuous… Read more: High-Speed Hob-Milling of Small Module Straight Bevel Gears: Principle, Simulation, and Machining Verification

In my research, I focus on the numerical simulation and wear analysis of a straight spur gear operating under dry friction conditions. The study is motivated by the frequent occurrence of oil‑lack or oil‑free situations in heavy‑duty mechanical transmissions, where gear surfaces experience severe wear and temperature rise, potentially leading to failure modes such as… Read more: Numerical Simulation and Wear Research of Straight Spur Gear in Dry Friction

I approached the problem of a real machined straight bevel gear as a digital manufacturing problem rather than as a purely theoretical gear-design problem. In my view, the tooth surface of a straight bevel gear is a three-dimensional free-form surface, and its actual geometry is affected by cutting-machine errors, fixture errors, tool wear, heat-treatment distortion,… Read more: Finite Element Analysis of Measured Straight Bevel Gear

1  Introduction In the context of promoting green development and energy conservation, gear transmission is advancing toward lightweight, high-efficiency, and low-noise directions. Herringbone gear transmission offers advantages such as compact structure, smooth operation, low axial force, and high load-carrying capacity, making it widely used in aerospace, marine, and metallurgical fields. The double helical star gear transmission… Read more: Meshing Efficiency Calculation and Macro-Micro Parameter Optimization of Herringbone Gear Systems

I investigated the thermal-mechanical behavior of high-speed wind-turbine miter gears used in the high-speed stage of a wind-turbine reducer. In this work, the term miter gears refers to the double-helical, herringbone-type miter gear pair that carries high load and high speed under complex service conditions. My purpose was to quantify how friction-induced heat, thermal deformation,… Read more: Thermal-Mechanical Coupling of Miter Gears

The design and manufacture of hyperboloidal gears, commonly known as hypoid gears, represent one of the most complex challenges in gear engineering. Their superior torque transmission capability and ability to accommodate non-intersecting, offset axes make them indispensable in automotive drivetrains, particularly in rear axles. Central to their performance is the tooth contact pattern—the elliptical region… Read more: A Comprehensive Analysis System for Hyperboloidal Gears

In my work on locomotive bogie drive systems, I have focused on one of the most critical components: the driving pinion gear shaft. These pinion gears transmit the motor torque to the axle gearbox, and their bearing seats must maintain an exact interference fit with the bearing inner rings. When a workshop discovered that several… Read more: Optimization of Pinion Gear Shaft Machining and Maintenance Processes

In my research on advanced manufacturing techniques, I have focused on the application of 3D printing for producing critical components in mechanical systems, particularly rotary vector reducers. The rotary vector reducer, often abbreviated as RV reducer, is a precision gearbox widely used in robotics and industrial automation due to its high torque capacity, compact design,… Read more: Static Analysis of 3D Printed Gears in Rotary Vector Reducers

I investigate the bending stress behavior of tooth roots in multi-modulus involute worm and helical gear pairs. In contrast to conventional worm and worm gear drives, a worm and helical gear transmission offers simpler design, easier manufacturing, improved lubrication, and lower sensitivity to assembly errors. These advantages make it attractive for automotive transmissions, power tools,… Read more: Bending Stress Characteristics of Multi-Modulus Worm and Helical Gear Pairs

I investigate the transmission efficiency of a lockable screw gear limited-slip differential. The screw gears in this differential provide smooth transmission, favorable meshing characteristics, and high friction. My goal is to elevate the transmission efficiency by analyzing the basic structure and functions of the differential, calculating the power losses from sliding and rolling friction for… Read more: Screw Gear Differential Efficiency

I propose and verify a practical method for grinding a face gear on a general cylindrical internal gear grinding machine. A face gear is a compact, high-ratio transmission element that can transmit motion between intersecting axes, and its manufacturing quality strongly depends on the accuracy of the generating motion and the grinding wheel setting. Instead… Read more: Face Gear Grinding on Cylindrical Internal Gear Grinding Machines

In this thesis, I systematically investigate the multi-state meshing-impacting nonlinear dynamic characteristics of spur gears under gear tooth breakage conditions. The research is motivated by the fact that spur gears are widely used in aerospace, automotive, and marine applications where tooth fractures can occur during prolonged service. In particular, I focus on two typical failure… Read more: Multi-state Meshing-impacting Nonlinear Dynamics of Spur Gears under Gear Tooth Breakage

In my work on gear design, I repeatedly return to the problem of calculating angular deflection in straight bevel gears. Straight bevel gears are widely used to transmit motion and power between intersecting axes, usually at a shaft angle of \(90^\circ\). For many applications, height deflection and a combination of height and tangential deflection are… Read more: Angular Deflection of Straight Bevel Gears

I focus on the chatter problem that appears during spiral bevel gear face hobbing. In this manufacturing process, the cutter head and the workpiece move in a coupled spatial relationship, and even a small relative vibration can alter the undeformed chip geometry, the instantaneous cutting force, and the final tooth surface. I therefore build a… Read more: Gear Hobbing Chatter State Identification

The advancement of intelligent manufacturing is a strategic priority in the era of the fourth industrial revolution. Within these advanced production systems, industrial robots represent a critical class of high-end equipment. Their performance, reliability, and precision are paramount. The rotary vector (RV) reducer is a core component in the joints of industrial robots, prized for… Read more: Dynamic Wear Characterization and Modeling of the Tooth Profile in RV Reducers for Industrial Robots

In the realm of precision gear manufacturing, gear honing stands out as a vital finishing process that significantly enhances the surface quality, accuracy, and performance of hardened gears. Traditional gear honing methods, particularly worm-type honing, have been widely adopted due to their efficiency and cost-effectiveness. However, these methods often produce parallel grooves on the tooth… Read more: Analysis of Meshing Patterns in Gear Honing with Oscillating Worm Tool

In modern mechanical transmission systems, particularly within the demanding environment of aerospace propulsion, bevel gears serve as critical components for redirecting power flow. Their reliable operation is paramount to the overall stability and safety of the system. However, during service, bevel gears are subjected to a complex interplay of cyclic loading, sliding friction, manufacturing tolerances,… Read more: The Remanufacturing of Bevel Gears: A Comprehensive Technical and Economic Analysis

In mechanical transmission systems, hyperboloid gears are pivotal components for transferring power between non-parallel and non-intersecting shafts. Their complex spatial tooth geometry, characterized by hyperbolic pitch surfaces, enables high torque capacity, smooth operation, and compact design, making them indispensable in automotive differentials, aerospace actuators, and industrial machinery. The performance of hyperboloid gears hinges on precise… Read more: Kinematic and Curvature Analysis of Hyperboloid Gears

The design and performance of power transmission systems critically depend on the understanding of gear tooth contact. Among various gear types, the double-enveloping worm gear drive, often simply referred to as a ‘screw gear’ set, is renowned for its high load capacity and multi-tooth contact. This analysis delves into the complex tooth surface generation of… Read more: Structural Analysis of the Worm Gear Tooth Surface in Modified Slant Plane Double-Enveloping Screw Gear Pairs

I study the vibration and noise behavior of a logarithmic spiral bevel gear from the standpoint of meshing-in impact. In my analysis, the logarithmic spiral bevel gear is treated as a special spiral bevel gear whose tooth trace follows a logarithmic spiral. Because the spiral angle of this curve is constant along the tooth, the… Read more: Logarithmic Spiral Bevel Gear Impact

In my study, I focus on a high-speed wind turbine miter gear pair used in the high-speed stage of a wind power gearbox. The miter gear is treated as a double-helical, herringbone-type transmission element because it provides high contact ratio, strong load capacity, smooth meshing, and good stability under high-speed and heavy-load conditions. I investigate… Read more: Thermal-Mechanical Coupling and Modification of High-Speed Miter Gears

The reliable operation of mechanical transmission systems is paramount in industrial applications, and spur gears constitute one of the most fundamental and widely used components. During operation, these systems are subjected to dynamic excitations arising primarily from the periodic variation in the number of gear teeth in contact. This inherent characteristic, combined with complex loading… Read more: Research on Multi-Fault Dynamic Response of Spur Gears Considering Tooth Root Transition Curve

In the field of mechanical transmission, spiral bevel gears are widely used due to their high transmission efficiency, compact structure, and reliability. They are critical components in applications such as machine tools, automotive systems, ships, and aerospace engines. With the trend toward high-speed, heavy-load, and lightweight designs, the demands on gear performance and dynamic characteristics… Read more: Study on the Evolution of Crack Extension Frequency Characteristics under Traveling Wave Resonance of Spiral Bevel Gears

I have developed a parametric computer-aided design system for screw gear drives because the design of a screw gear pair involves many coupled parameters, large data tables, and repeated geometric computations. A screw gear transmission, commonly realized as a cylindrical worm and a worm wheel, transfers motion and torque between two non-intersecting shafts. The design… Read more: Parametric Design of Screw Gear Drives

In recent years, the rapid expansion of urban areas has led to a significant increase in the demand for efficient and safe public transportation. Subway systems have become a primary mode of travel for millions of people. The safety of subway vehicles is paramount, and the transmission gearbox is a critical component that directly affects… Read more: Bending Fatigue Life Prediction and Optimization of Helical Gears for Subway Vehicle Transmission