In modern industrial systems, transmission gears function as critical mechanical components, much like human joints that connect and drive various equipment. From precision machine tools to massive aero-engines, from everyday vehicles to complex industrial machinery, these gears are ubiquitous, providing a solid foundation for efficient power transmission and precise control.
Global market size
According to GII data, the global gear manufacturing market reached $260.8 billion in 2023 and is projected to grow to $385.6 billion by 2030, with a compound annual growth rate (CAGR) of 5.7%.
Data from authoritative market research institutions reveals that the global gear market surpassed the 1.3112 trillion yuan threshold in 2023, projected to maintain a 3.8% compound annual growth rate (CAGR) and reach 1.7077 trillion yuan by 2029. This sustained growth reflects robust demand for transmission gears in global manufacturing. With the rise of emerging industries and the modernization of traditional sectors, the transmission gear market demonstrates vast development potential.
China market steady growth
China’s gear industry has maintained a steady growth pace in recent years. From 2016 to 2022, the annual compound growth rate was 5.9%, with the market size reaching 330 billion yuan in 2022 and further increasing to 346 billion yuan in 2023. As a global manufacturing powerhouse, China boasts a complete industrial system. The booming development of industries such as automobiles, machinery manufacturing, and aerospace has injected continuous vitality into the transmission gear market. Moreover, with the optimization and upgrading of domestic industrial structures and the accelerated development of high-end manufacturing, the transmission gear market is expected to achieve even faster growth.
Main application areas of transmission gears
The core support in the field of industrial machinery
In the machine tool industry, gear transmission is extensively utilized in spindle drive systems and feed mechanisms of various equipment such as lathes, milling machines, and planers. Its high-precision speed and torque control capabilities ensure machining accuracy, forming the foundation for precision manufacturing. For lifting machinery, the hoisting and traveling mechanisms require exceptional torque output. Gear transmission’s reliable power transmission ensures stable crane operation under heavy loads. In printing machinery, gear transmission powers drum drives and paper conveying systems, while in textile machinery, it enables synchronized movement and speed regulation of components like spinning and weaving machines. These applications all rely on efficient gear transmission to maintain high production efficiency across industries.
The Power Bond in the Automotive Industry
Within an automobile engine, critical components like the camshaft and crankshaft rely on gear transmission for power delivery, with their stable and reliable performance ensuring smooth operation. The transmission system achieves flexible gear ratios through precisely engineered combinations of gears, meeting diverse speed and torque demands during acceleration, cruising, and other driving conditions. The differential’s gear mechanism acts as a “balance master” during turns, allowing the left and right wheels to rotate at different speeds to ensure stability and handling.
Furthermore, with the advancement of automotive electrification and smart technologies, precision gears are indispensable for cutting-edge components such as EPS, wire-controlled steering, and wire-controlled chassis.
High-precision and advanced requirements in the aerospace industry
The intricate and critical transmission systems in aircraft engines extensively utilize gear mechanisms. These gears must demonstrate exceptional capabilities to withstand high rotational speeds and substantial torque, while maintaining precise and reliable power delivery. This ensures stable engine operation during high-altitude flights. Similarly, helicopter transmission systems for main and tail rotors employ gear-driven mechanisms. Their efficient power transfer performance provides crucial safeguards for both safe flight operations and agile maneuverability.
Application of various robots
In robotic motion control, precision gear design integrated with advanced control algorithms enables transmission gears to deliver sensitive and accurate control over all robotic joints, ensuring exceptional stability and precision during complex operations. For instance, in robotic arms, adjusting the gear ratio allows precise control of rotational speed and torque, meeting diverse requirements for grasping, transporting, and other tasks. Moreover, as robots handle varying loads during different tasks, the transmission gears dynamically adjust their output torque to adapt to specific demands—such as increasing torque during heavy lifting to enhance load-bearing capacity.
Different types of transmission gears have distinct characteristics and application scenarios. Bevel gears are used to transmit power between parallel shafts, while helical gears reduce noise and vibration to improve transmission smoothness. Conical gears alter the direction of power transmission within robots. Worm gear mechanisms achieve high reduction ratios in confined spaces with self-locking functionality, making them ideal for robotic joints and hand grippers.
Widespread application in other fields
In the field of medical precision equipment, the precise positioning and low noise of transmission gears facilitate the automation of every step in medical diagnosis and treatment processes.
In the field of agricultural machinery, the transmission system of tractors, harvesters and other equipment uses gear transmission to achieve reasonable power distribution and precise speed adjustment, which improves the efficiency and quality of agricultural production.
The equipment of mine machinery, such as crusher and conveyor, need strong power transmission. Gear transmission meets the operation demand of mine under harsh working conditions by virtue of its high load capacity.
In wind power generation, the gearbox of wind turbines converts the low-speed rotation of the rotor into high-speed rotation through gear transmission, enabling efficient clean energy production.
Research and Manufacturing Difficulties of Transmission Gear
The development and manufacture of transmission gear is a challenging system engineering, which faces many technical difficulties in the aspects of material, design, processing and testing.
In material selection and quality control, it is essential to identify materials with high strength, excellent wear resistance, good toughness, and fatigue resistance, while ensuring high stability in material quality to eliminate issues like compositional deviations and internal defects. To address this challenge, companies conduct in-depth research on material properties, closely aligning with the actual operating conditions of gears, and select the most suitable materials through rigorous testing. Additionally, they establish long-term stable partnerships with high-quality material suppliers and strengthen strict inspection and acceptance procedures for raw materials. Furthermore, materials undergo pre-treatment processes such as tempering and normalizing to optimize their microstructure and performance.
High-precision design and optimization present equally formidable challenges, requiring meticulous calculation of critical gear parameters including module, tooth count, pressure angle, and tooth width to satisfy stringent requirements for transmission efficiency, load-bearing capacity, and operational stability. Furthermore, engineers must account for complex real-world factors such as thermal deformation and wear during comprehensive optimization. Companies utilize advanced Computer-Aided Design (CAD) and Computer-Aided Engineering (CAE) software to construct precise gear models, conducting multi-phase simulation analyses and iterative optimizations. Through Design of Experiments (DOE) methodologies combined with field testing, design parameters undergo repeated validation and fine-tuning.
In precision machining and surface quality control, it is essential to minimize tooth profile errors, tooth direction errors, and cumulative pitch errors while ensuring uniform surface roughness and hardness, and preventing defects such as tool marks or burn marks. Companies utilize advanced equipment like high-precision gear hobbing machines, gear hobbing machines, and gear grinding machines, with regular precision checks and maintenance. By optimizing machining processes, selecting appropriate cutting tools and parameters, and employing multi-step machining with repeated measurement corrections, processing accuracy is enhanced. Additionally, online inspection technology is employed to strengthen quality control during machining, enabling timely detection and correction of errors.
The heat treatment process requires precise control of parameters such as temperature, duration, and cooling rate to achieve optimal microstructure and properties, including tooth surface hardness and core toughness. It is essential to prevent deformation during heat treatment to ensure the gear’s precision remains unaffected. Companies utilize advanced equipment like vacuum quenching furnaces and carburizing furnaces to enhance temperature and atmosphere control accuracy. Scientifically designed heat treatment specifications are formulated, with customized optimizations based on factors such as material, size, and shape. Pre-treatment processes like stress-relief annealing are performed before heat treatment, followed by necessary straightening and precision adjustments afterward.
The Performance Testing and Evaluation System of Transmission Gear Products
In order to ensure the quality and performance of the transmission gear, a complete product performance testing and evaluation system is needed.
The tooth profile and tooth direction accuracy are measured by the tooth profile error, tooth direction error, circumference cumulative error and so on. The gear measuring center and other precision measuring equipment are used to measure the tooth profile and tooth direction of the gear in all directions, and the error data is obtained, and then the gear precision grade is evaluated.
The tooth surface hardness must meet the design requirements to ensure wear resistance and contact strength, while the core hardness should possess sufficient toughness to withstand impact loads. Hardness testers are used to measure both surfaces and the core, with multi-point measurements averaged and the uniformity of hardness distribution verified.
Contact fatigue strength and bending fatigue strength are determined through calculations and experiments to establish the gear’s contact fatigue limit and bending fatigue limit, evaluating its fatigue resistance under long-term alternating loads. By conducting gear fatigue tests that simulate actual operating conditions of load and rotational speed, the gear undergoes loading tests. The number of fatigue failure cycles and failure modes are recorded and compared with design standards for analysis.
Transmission efficiency is one of the important indexes to measure the performance of gear transmission. Transmission efficiency is calculated by measuring the input power and output power of gear transmission system under different load and speed.
The noise level is directly related to the working environment and comfort of the gear transmission system, and is also a key factor in evaluating the performance of gears. In specific environments such as semi-anechoic chambers, equipment like sound level meters is used to measure the noise levels during gear transmission, and the frequency components and sources of the noise are analyzed.
Analysis of the Enterprise Structure in the Field of Transmission Gear
Well-known companies from abroad
Gleason (USA): As a global leader in gear technology solutions, the company operates across gear design, manufacturing, sales, and the R&D and production of related equipment such as honing machines. It also provides design software for gears and power transmission systems, measurement systems, and automation solutions. Gleason’s transmission gears boast exceptional precision, perfectly meeting the demanding requirements of high-end sectors like aerospace and automotive. In aerospace applications, these gears withstand high-speed rotation and heavy loads, with power ranges suitable for high-power transmission scenarios like large passenger aircraft engines. In the automotive sector, they fulfill the power transmission needs of high-performance vehicles.
KLINGELNBERG (Switzerland), a global leader in the gear industry, specializes in developing and manufacturing gear processing machines, precision measurement centers for various axisymmetric workpieces, and custom high-precision transmission components. Its transmission gear products are renowned for their high precision and performance, particularly helical bevel gears and cylindrical gears, which are widely used in automotive, marine, and industrial machinery sectors. The company offers a broad power range, from medium-power automotive transmissions to high-power marine propulsion systems, with corresponding premium products available.
Kohara (KHK, Japan): A renowned Japanese gear manufacturer specializing in both standard and custom gear solutions, including cylindrical gears, bevel gears, worm gears, and more. Renowned for their precision and consistent quality, these products are widely used in industrial machinery, automation systems, and food processing equipment. The power output varies by product type, yet generally meets the power requirements of most industrial devices and automated production lines.
Aisin (Japan): As a Fortune Global 500 company, Aisin excels in automotive transmission gears, holding a leading global market share. Its automatic transmission gears are renowned for their high precision and reliability, precisely meeting the power transmission needs of various vehicle types. The power range spans from economy cars to luxury vehicles.
SEW-EURODRIVE (Germany): A globally recognized leader in gear reducer technology, with manufacturing facilities across 52 countries. Its transmission gear products, as essential components of gear reducers, are widely used in various industrial applications. These products feature high efficiency, durability, and low noise, adapting to diverse complex working environments and operational requirements. The product range spans from compact reducers for industrial automation to large-scale gear solutions for heavy machinery, ensuring compatibility across all power applications.
Flender (Germany), founded in 1899, is a German industry leader in mechanical transmission systems, particularly dominating the wind power and heavy industry sectors. Acquired by Siemens Electric in 2005, the company offers standardized product lines across various power ranges, featuring modular designs, high interchangeability, and exceptional transmission efficiency. Its transmission gear products are specifically engineered for wind power and heavy industry applications, delivering high strength and reliability to withstand the immense torque of large wind turbines and the heavy-duty loads of industrial equipment. The product range primarily focuses on high-power applications in these sectors.
HarmonicDrive (Japan): A global leader in motion control technology, Harmonic Drive’s modular harmonic reducers feature lightweight design, zero gear clearance, and exceptional torque capacity. These innovations power cutting-edge applications including industrial robotics and semiconductor LCD manufacturing systems. While the drive gears are not the most energy-intensive components, their pivotal role in harmonic reducers delivers unmatched precision in high-precision transmission, perfectly meeting the stringent torque and accuracy demands of industrial robots and other precision-driven equipment.
Nabtesco (Japan): Jointly holds a 75% global market share in precision reducers with Harmonic Drive, playing a pivotal role in industrial robotics. Its patented two-stage cycloidal reducer features near-zero backlash, minimal transmission error, and exceptional torsional rigidity. The transmission gears, engineered with a unique cycloidal design, deliver high torque capacity. The power range is tailored to industrial robots’ demands—typically medium power with stringent precision and reliability requirements.
Bonfiglioli (Italy), founded in 1956, is the leading gear reducer manufacturer in Italy, specializing in gear-driven motors, planetary gear reducers, electric motors, and frequency converters. Renowned for its reliability in power transmission and control systems, the company boasts a global sales network. Its transmission gear products are designed for diverse industrial applications, offering a wide power range—from compact industrial equipment to heavy-duty construction machinery.
Rulisi Reducer (Rulisi, Italy): A renowned European brand, 100% locally manufactured in Europe. Featuring multi-face mounting, multiple input shafts, standard IEC flanges, a complete intermediate series, and maintenance-free operation, it offers numerous advantages. Specifically designed for the mixing and injection molding industries, its products are celebrated for exceptional quality and reliability in heavy industrial applications. The transmission gear products can withstand high loads and harsh working conditions, with power ranges primarily targeting large-scale heavy industrial equipment, typically offering medium to high power output.
IDC Industries, Inc. is a U.S.-based innovative gear manufacturer and reducer service provider, seamlessly integrating standardized power transmission solutions with customized machining, gear cutting, and gearbox maintenance services. Its transmission gear products are tailored to customer needs, serving diverse industrial applications across a wide power spectrum to meet specific requirements.
Bauer Reducer: Founded in 1927, this German company has become the global preferred supplier of high-quality, reliable gear motors and an industry leader in innovative, energy-efficient reducer solutions. Its transmission gear products are widely used in sectors such as light industry, construction machinery, steel, power plants, coal, mining, papermaking, automotive, and ports, with power coverage that fully meets the transmission needs of general equipment in these fields.
ZF (Germany): As a global leader in automotive components, ZF boasts cutting-edge expertise in gear transmission technology. It provides transmission system solutions for numerous automotive brands, with products spanning gearboxes and transfer cases, securing a dominant position in the automotive gear transmission market.
IMS Gear (IMS Gear SE & Co. KgaA, Germany): Founded in 1863 in the Black Forest region of Germany, it initially served as a subcontractor for the local watch industry, producing precision components. Over time, the company grew and expanded its business into the automotive parts manufacturing sector. After more than 150 years of development, IMS Gear has evolved from a small company focused on gear production into a renowned enterprise in gear and transmission technology, offering outstanding solutions in components, assemblies, and gears. With nine factories worldwide and approximately 3,100 employees, it has production and sales bases in the United States, Mexico, China, Japan, and South Korea.
NORD (Germany), founded in 1965, is globally renowned for its professional production and sales of high-quality reducers, motors, frequency converters, and servo control systems, holding a leading position in the international power transmission and control industry.
Sumitomo Transmission Technology (Japan): Since its inception in 1939, the company has become synonymous with high-performance and reliable gearboxes through its innovative designs. Its product range spans from small reduction motors (watt-level) to large gearboxes (tens of kilowatts), complemented by a diverse portfolio including frequency converters and various motor types.
Leading domestic companies
Nanjing High Precision Transmission Equipment Manufacturing Group Co., Ltd. (Nanjing High Precision Transmission Equipment) NGC: Founded in 1969 and listed in Hong Kong in 2007. As a recognized leader in China’s gear industry, it has achieved world-leading levels in technology, equipment, and product performance. The company owns a state-recognized enterprise technology center and undertakes multiple major national science and technology projects. Its main products include building materials-specific gearboxes, metallurgy-specific gearboxes, wind power generation gearboxes, and railway locomotive gearboxes, holding an absolute advantage in domestic high-speed heavy-load gearboxes and wind power gearboxes markets.
Hangzhou Qianjin Gearbox Group Co., Ltd., founded in 1960, is a key high-tech enterprise under China’s National Torch Program. The company offers a wide range of products, including marine gearboxes, construction machinery transmissions, automotive transmissions, wind power gearboxes, and over a thousand varieties across ten major categories. Its “Qianjin” brand products are popular in more than 30 provinces, municipalities, and autonomous regions in China, and are exported to over 40 countries and regions worldwide, enjoying a strong reputation and significant market share in the industry.
China Shipbuilding Industry Corporation Chongqing Gearbox Co., Ltd. is a large state-owned military enterprise specializing in the research, development, and production of high-speed and low-speed heavy-duty gearboxes, affiliated with China Shipbuilding Industry Corporation Limited. The company boasts years of profound R&D and production experience, having undertaken numerous national science and technology breakthrough projects, and has accumulated substantial strength and unique advantages in gear transmission technology for the fields of shipbuilding and military industry.
Zhuzhou Gear Co., Ltd., founded in 1958, saw its controlling stake acquired in 2005 through the merger of Weichai Power and Xianghuoju. Since 2010, the company has invested heavily in establishing China’s largest heavy-duty drive axle gear R&D and manufacturing base, which also ranks as Asia’s top facility. Its new energy vehicle (NEV) transmission systems now command over 25% market share, leading the industry.
Zhuzhi Company overcame multiple challenges in design, manufacturing, and testing to successfully develop a full range of crawler crane reducers, spanning from 800 N·m to 2 million N·m, achieving complete import substitution. In 2023, its crawler crane reducers ranked first in global market share.
In 2022, Zhuchai Company’s yaw pitch reducer—a core component for wind power—was adopted by leading wind energy manufacturers.
Double Ring Transmission: Since its establishment in 1980, it has always focused on the research, development, manufacturing, and sales of core mechanical transmission components — gears and their assemblies, and has grown into one of China’s leading professional gear product manufacturers and service providers. The products feature high precision and stable quality, covering multiple fields such as passenger vehicles, commercial vehicles, new energy vehicles, rail transit, non-road machinery, industrial robots, consumer gears, and energy equipment. The products cover a wide range of power outputs, meeting various transmission needs from low to high power.
Jingduan Technology: As a professional manufacturer of automotive precision forgings in China, it mainly engages in the research, development, production, and sales of precision forgings such as automotive differential half-shaft gears, planetary gears, and coupling teeth. The differential gears it produces, through precision forging processes, feature high strength and high precision. The product power range primarily focuses on the power intervals required by automotive transmission systems, generally ranging from tens of kilowatts to hundreds of kilowatts.
Guomao Co., Ltd. is a leading domestic manufacturer of gear reducers, specializing in general-purpose and high-power models. Its transmission gear products, as critical components of gear reducers, are widely used across various industrial sectors. The gear reducers offer a broad power range, covering everything from low-power applications in small equipment to high-power requirements in large industrial machinery.
Zhongda Lide specializes in the R&D, production, sales, and service of critical components for mechanical transmission and control systems. Its core products include precision reducers, speed-reducing motors, and intelligent actuator units, forming an integrated “reducer + motor + drive” product architecture. The company’s transmission gears feature high precision and are primarily used in industrial automation and smart manufacturing equipment. The power range varies across different product models and application scenarios, typically covering the power spectrum commonly required for industrial equipment.
Zhongma Transmission specializes in the R&D, production, and sales of automotive transmissions and vehicle gears. Its product portfolio includes manual transmissions, automatic transmissions, and new energy vehicle transmissions, along with corresponding gear systems. The company’s offerings cater to diverse power transmission needs across vehicle types, with a broad power spectrum ranging from low-power household sedans to high-power commercial vehicles.
Lan Dai Technology specializes in the R&D, design, development, manufacturing, and sales of powertrain assemblies, transmission components, and die-cast products. Its transmission gear products include automotive transmission gears and engine gears.
Summary
In the field of transmission gears, there remains a noticeable gap between domestic and international enterprises. Foreign companies, with their long-standing history and substantial expertise, invest heavily in fundamental research. They possess comprehensive foundational data and advanced specialized design software, leading in the development and application of new materials as well as the design and manufacturing of high-end products. For instance, in high-precision transmission gear applications such as automotive automatic transmissions and high-speed rail drive units, foreign enterprises have achieved technological maturity and hold a dominant position.
Chinese enterprises generally lag in fundamental research, with critical technologies and high-end products still heavily reliant on imports. In manufacturing processes, foreign companies utilize gear materials with superior purity and uniformity, advanced heat treatment techniques that effectively control deformation and cracks, along with precision machining tools and equipment. However, domestic manufacturers fall short in gear material quality, heat treatment process stability, and advanced processing equipment, resulting in inferior product precision, reliability, and service life compared to international counterparts.
However, thanks to the strong domestic industries driving the supply chain, domestic enterprises have made remarkable progress in recent years and achieved breakthroughs in some areas.
In the maritime sector, Hangzhou Gear Group has developed China’s most powerful GWC85/100 marine gearbox, overcoming key challenges including high-torque clutches, heavy-duty sliding bearings, and high-flow hydraulic system design. This innovation delivers significant energy savings and reduced carbon emissions compared to international competitors, while outperforming customer expectations in directional control and noise levels. The group’s independently developed integrated propulsion system incorporates cutting-edge technologies such as adjustable-pitch propellers, remote control, and automated fault diagnosis, achieving full automation in ship navigation and breaking the long-standing foreign technological monopoly.
In the field of high-speed rail, in 2014, the “CRH380A Gearbox Drive Device” developed by China CRRC Qishuyan was included in the National Key New Product Plan. In the same year, Chongqing Kairui accepted the invitation from the host manufacturer to start developing high-speed rail gearboxes. In January 2017, it completed the CRCC product certification, and its CW350 (D) gearbox began to be supplied in batches for the “Fuxing” trains. Since then, domestic high-speed rail gearboxes have been continuously upgraded and improved, with their application scope expanding, gradually achieving full coverage of domestic high-speed rail lines.
In the construction machinery industry, Zhuzhou Gear Co., Ltd. has overcome multiple challenges in design, manufacturing, and testing to successfully develop a full range of crawler crane reducers, achieving complete import substitution. In 2023, the company maintained its leading position in the global market share for crawler crane reducers.
In the field of small precision reducers, domestic companies such as Lüde Harmonic, Shuanghuan Transmission, and Zhitong Technology have achieved collective breakthroughs.
Looking ahead, the rapid growth of industries like new energy vehicles, aerospace, and robotics will undoubtedly propel precision gear transmission enterprises to catch up and surpass.
