Yes. We provide flexible MOQ and fast prototyping services. Whether you need a single prototype or a small batch run, we can deliver high-precision gears within 2–3 weeks.
- support@ddgear.com
- North 3F, Building 13-2, Zhixin Park, NO.1099 Xianhua South Street, Wucheng, Jinhua, Zhejiang, China.
Drive Durable Gear
Category
From robotics to EVs, from medical to automation — precision gears for every industry.
PRODUCTS
Reliable precision gears for robotics, automotive, and beyond.
Sprockets
Sprockets are profiled wheels with teeth that mesh with roller or conveyor chains to transmit mechanical power and motion between shafts or to drive tracks and conveyors.In a typical chain drive, the driving sprocket engages the chain and pulls it around a loop; the chain then rotates a driven sprocket or moves a conveyor, providing a simple, efficient, and robust means of power transmission for machinery, vehicles, and material-handling systems.
DD Gear designs and manufactures custom sprockets for chain-driven systems in agricultural equipment, construction and material-handling machinery, automated conveyors, robotics, and other industrial applications. All sprockets are made to order based on your drawings, chain standards, and operating conditions. We focus on precision tooth profiles, controlled bore and hub tolerances, and appropriate materials and heat treatments so that each sprocket delivers reliable, low-maintenance performance in demanding environments—whether it is part of a compact robot axis or a heavy-duty conveyor line.
Crown Wheel and Pinion
The Crown Wheel and Pinion – Custom Differential Gear Set is the core gear pair inside an axle or final drive, also known as the ring and pinion gear set. The small pinion gear receives torque from the driveshaft, transmission, or e-motor and meshes with the larger crown wheel (ring gear). Together, they turn the drive through 90° and provide the final reduction ratio between the driveline and the wheels.By selecting the correct number of teeth on the crown wheel and pinion, the gear set simultaneously reduces speed and increases torque, adapting powertrain output to the axle load and tire size. For example, a 41-tooth ring gear driven by a 10-tooth pinion yields a 4.10:1 ratio – the pinion turns 4.1 times for each revolution of the crown wheel. In modern vehicles and off-highway machines, these gears are usually spiral bevel or hypoid designs, which offer higher torque capacity, smoother engagement, and lower noise than straight bevel gears.
DD Gear supplies custom crown wheel and pinion sets on a build-to-print basis for axles, differentials, transfer cases, and e-axles. We focus on accurate tooth geometry, controlled contact patterns, and robust materials and heat treatments so that each matched gear set delivers quiet, durable operation under high torque and cyclic loading in automotive, off-highway, and new-energy applications.
Worm Gear
A worm gear set consists of a screw-like worm meshing with a toothed worm wheel arranged at a right angle. Unlike conventional spur or helical gear pairs, the helical thread of the worm engages the teeth of the worm wheel with a sliding action, allowing the system to achieve very high reduction ratios—often up to about 100:1 in a single stage while keeping the gearbox compact.Because of the geometry and friction between the worm and wheel, many worm drives also show a self-locking effect, meaning the worm can drive the wheel but the wheel cannot back-drive the worm under normal conditions. This property, together with the high single-stage ratio, smooth operation and low noise, makes worm gears a preferred solution for hoists, elevators, conveyors, valves, actuators, steering systems and various positioning mechanisms where compact layout and load-holding capability matter.
DD Gear designs and manufactures custom worm and worm wheel sets according to customer drawings. Typical configurations use a case-hardened steel worm running against a bronze or brass worm wheel, combining strength with good wear and sliding properties. With small-module precision machining, optimized materials and heat treatment, and strict accuracy control based on international worm-gear standards, we help customers build efficient, durable, and safe worm-drive solutions for industrial machinery, automation, robotics and motion systems.
Helical Gear
The Helical Gear – Custom Helical Gear for Smooth, High-Load Transmission is a cylindrical gear whose teeth are cut at an angle to the gear axis, forming a helix around the pitch circle. Because the teeth engage gradually along the helix rather than meeting all at once, helical gears transmit torque with smoother, quieter operation and less vibration than spur gears.The inclined teeth also mean that multiple teeth are in contact at the same time, which increases tooth strength and load-carrying capacity, allowing helical gears to handle higher speeds and higher power than spur gears of the same size. With proper design and lubrication, industrial helical gearboxes can reach efficiencies in roughly the 94–99% range per stage, comparable to spur gears.
Helical gears can transmit power between parallel shafts (standard helical gear pairs) and, in crossed-axis form, between non-parallel shafts (screw gears), giving designers flexibility in gearbox layout. DD Gear focuses on small-module, high-precision helical gears produced to international accuracy standards (ISO 1328 / DIN 3961/3962). We manufacture external and internal helical gears according to customer drawings for EV transmissions, industrial gearboxes, robotics actuators, AGV drive units, and other automated machinery where quiet running, efficiency and durability are critical.
Synchronizer
A synchronizer is the friction and locking device inside a synchromesh gearbox that matches the rotational speeds of the shaft and the selected gear before their dog teeth engage. Instead of sliding gears directly into mesh—which would cause grinding when speeds differ—the synchronizer uses a small cone clutch formed by the synchronizer ring (blocker ring) and the gear’s friction cone to create friction torque and accelerate or decelerate the rotating parts. Once the speeds are close enough, the sleeve can move past the ring and lock the gear to the shaft, giving a smooth, quiet shift.A typical synchronizer unit includes a hub splined to the shaft, a sliding sleeve, one or more synchronizer rings with friction linings, and keys/springs or struts that control movement and locking force. Modern designs may use single-cone, double-cone or multi-cone arrangements to increase effective friction area and reduce shift force.
Synchronizer rings were traditionally made from brass or bronze, but many transmissions now use sintered steel, molybdenum or carbon-based friction linings to handle higher torques and improve wear life. DD Gear manufactures custom synchronizer components—primarily synchronizer rings, mating cones and related precision parts—according to customer drawings for truck, bus, passenger-car and off-highway gearboxes, including conventional MT and AMT/DCT platforms. Our focus is tight control of cone geometry, friction surfaces and tooth accuracy so each component supports reliable, comfortable gear shifting over the full transmission life.
Spur Gear
The Spur Gear – Custom Spur Gear for Efficient Power Transmission is a cylindrical gear with straight teeth cut parallel to the gear axis. Spur gears are the most common and fundamental gear type used to transmit motion and power between parallel shafts in mechanical systems. Their simple geometry makes them easy to design and manufacture while delivering a precise, constant speed ratio between driving and driven shafts.Because spur gears operate primarily with rolling contact along the tooth profile and have no helix angle, they can achieve very high mechanical efficiency—typically in the 94–99% range for well-designed meshes—making them one of the most efficient gear types for moderate ratios and speeds. At higher speeds, however, the sudden engagement of straight teeth can generate more noise and vibration than helical gears, so spur gears are generally preferred for moderate-speed, cost-sensitive, and compact parallel-shaft applications.
DD Gear manufactures custom spur gears according to customer drawings, focusing on small-module, high-precision components for EV transmissions, robotics, AGVs, medical devices, machine tools, and other automated equipment. With accuracy controlled under international cylindrical gear standards such as ISO 1328 and related DIN/AGMA systems, we provide spur gears that combine high efficiency, consistent accuracy and robust durability in demanding applications.
Shaft
A shaft is a rotating machine element that transmits power and torque from one location to another and supports rotating components such as gears, pulleys, sprockets and couplings. In powertrain systems, transmission shafts are subjected to combined torsion and bending from gear forces, chain or belt loads, and their own weight, so they must be designed for fatigue strength and stiffness over long service lives.DD Gear focuses on custom transmission shafts and gear shafts produced to customer drawings. These include input shafts, output shafts, gear shafts with integral gears, spline shafts and intermediate shafts used in EV drives, truck and off-highway gearboxes, industrial gearboxes, AGV drive units and automation equipment. Typical designs use forged alloy steels such as 42CrMo4 / AISI 4140 / SCM440 and related grades, which are widely used for heavily loaded shafts due to their strength and toughness.
Shaft performance depends not only on material and heat treatment, but also on accurate bearing seats, fits and runout. DD Gear machines shaft journals, shoulders, splines and gear seats to tight tolerances based on ISO 286 fits for holes and shafts, helping customers achieve stable alignment, low vibration and long bearing and gear life. With small-module precision gearing capability inside the same plant, we can also supply integrated gear-shaft components, reducing assembly interfaces and improving concentricity.
Bevel Gear
The Bevel Gear – Custom Bevel & Hypoid Gears for Angular Power Transmission is used to transmit motion and torque between intersecting or crossing shafts, typically arranged at a right angle. Bevel gears have teeth formed on the surface of a truncated cone, allowing power to “turn a corner” while maintaining a defined speed ratio.According to international standards such as ISO 23509, the term “bevel gears” includes straight bevel, spiral bevel, zerol bevel and hypoid gears. Straight bevel gears have straight teeth and are widely used where speeds and noise requirements are moderate, while spiral bevel gears use curved teeth to provide more gradual engagement, higher contact ratio and greater load capacity. Hypoid bevel gears, with offset axes, are commonly applied in automotive differentials and drive axles to handle high torque with smooth operation.
DD Gear designs and manufactures custom bevel and hypoid gear sets based on customer drawings and specifications. Typical applications include automotive and EV differentials, steering systems, right-angle gearboxes for machinery, robotic joints and AGV drive axles, where compact angular transmission, efficiency and durability are essential. Geometry is designed in line with ISO 23509 and related bevel gear standards, while accuracy follows recognized systems such as DIN 3965 and the ISO bevel gear accuracy tables published via AGMA/ISO. With DD Gear’s focus on small-module precision gearing for emerging industries, we help customers build reliable angular drives with consistent contact patterns and long service life
ABOUT US
PRECISION THAT DRIVES THE FUTURE
Immerse yourself in the world of high-precision gears engineered for robotics, EVs, and intelligent automation. From humanoid robots to advanced electric vehicles, DDGear provides customized gear solutions that combine accuracy, durability, and quiet performance.
We are committed to innovation and reliability — every gear we produce is designed to make our customers’ assembly easier, systems more efficient, and operations more stable.
- 15+ Years of gear manufacturing experience
- 30+ Countries served worldwide
- 4 Grade Accuracy or better in precision standards
- 2–3 Weeks fast prototype delivery
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Years of Gear Manufacturing
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Technology Patent
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CNC & Gear Machining
CASE
Precision gears that empower robotics, EVs, and advanced machinery worldwide.
EV Gear – Custom Helical Reduction Gears for Passenger EV Drive Unit
Case Highlights
A new-energy vehicle OEM was developing a front-drive e-axle for a C-segment passenger EV. The original prototype reducer used standard helical gears, but whine noise at highway speeds and mesh efficiency were not yet at target.
DD Gear delivered a two-stage small-module helical gear set with optimized micro-geometry and case-hardening steel (18CrNiMo7-6), a material widely used in high-load automotive gears thanks to its strong, tough core and wear-resistant case. After tuning on DD Gear prototypes, the project achieved:
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Quieter mesh in key speed ranges (improved interior NVH impression).
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Higher mesh efficiency, contributing to better energy consumption. Research shows that properly optimized helical gears and surface finishing are essential for high-efficiency EV reducers.
Customer Background & Project Scope
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Customer industry: New-energy passenger vehicle OEM.
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Application: Single e-axle with a two-stage helical reduction between a high-speed PMSM traction motor and the differential.
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Target vehicle: Front-wheel-drive compact EV used for city and highway commuting.
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Key requirements:
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High efficiency over WLTP-type drive cycles.
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Very low gearbox whine, because EVs lack engine masking; tonal gear noise is easily heard.
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Consistent quality at automotive mass-production volumes.
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The OEM’s baseline design already used helical gears, but gear micro-geometry, material grade and grinding needed to be improved to meet aggressive NVH and durability targets.
Challenges
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Gear whine around cruising speeds
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Interior tests showed noticeable tonal noise from the reducer at typical mesh frequencies during 80–110 km/h cruising.
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Even though helical gears inherently run smoother and quieter than spur gears, transmission error (TE) and manufacturing deviations can still excite annoying tones in EVs.
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Efficiency & thermal performance
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The reducer needed better mesh efficiency to support competitive kWh/100 km figures.
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Literature indicates that finely ground or polished helical gear flanks and optimized micro-geometry are key to reducing losses and avoiding micropitting in EV gearboxes.
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Durability at high speed & torque
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High input speed and peak torque demanded a deep case-hardened alloy steel with good core toughness. 18CrNiMo7-6 / 17CrNiMo6 case-hardening steels are commonly used in heavy-duty industrial and automotive gears for this reason.
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DD Gear Solution
1. Helical Gear Design & Micro-Geometry
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Two-stage helical layout
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Maintained the overall ratio requested by the OEM, but adjusted tooth counts and helix angles to improve contact ratio and mesh kinematics.
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Helical gears are preferred in EV transmissions because gradual tooth engagement reduces impact, vibration and noise compared with spur gears.
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Multi-objective micro-geometry optimization
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Applied profile and lead modifications (crowning, end-relief) based on contact and dynamic simulations to minimize loaded transmission error over the main torque/speed window. Similar studies show that careful tooth modification is an effective method to reduce vibration and noise in helical gear transmissions.
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Focused on those gear pairs contributing most to audible whine, following EV transmission noise analysis practices.
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2. Materials & Heat Treatment
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Case-hardening steel
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Selected 18CrNiMo7-6 for high-load gears; this case-hardening steel offers excellent surface hardness, core strength and toughness for gears and shafts in demanding transmissions.
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Case depth and hardness were specified to match the OEM’s load spectrum.
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Heat treatment & finishing
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Carburizing + quenching followed by fine gear grinding; grinding is recommended in EV gear design guidelines to achieve high efficiency and reduce micropitting risk.
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Surface finishes were tuned to support low-viscosity oils used for efficiency in modern EV transmissions.
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3. Manufacturing & Gear Accuracy
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ISO 1328 accuracy
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Tooth profile, helix deviation and pitch controlled to ISO 1328 Grade 4–5, a high accuracy class suitable for low-noise, high-speed helical gears.
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Process control
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SPC on critical dimensions, flank deviations and runout.
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Routine gear-pair tests for TE, loaded contact pattern, and backlash before release.
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Results
After adopting the DD Gear gearset and running multiple prototype loops:
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NVH
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Interior measurements showed significant reduction in tonal gear noise in the previously critical speed bands.
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The cabin sound profile became more dominated by road and wind noise, which is the typical design goal for refined EVs.
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Efficiency & thermal behavior
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Bench tests indicated a measurable improvement in reducer efficiency (in line with studies that show optimized helical gear design and finishing can boost efficiency).
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Temperature rise of the gearbox oil under steady-state highway operation was reduced compared with the baseline design.
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Durability & robustness
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Endurance testing under the OEM’s duty cycles showed stable contact pattern and no early micropitting or scuffing in the test window.
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The OEM approved the DD Gear design for SOP and listed DD Gear as a key gear supplier for this EV program.
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Typical Technical Specifications
Representative; DD Gear customizes parameters for each EV platform.
| Item | Parameter |
| Gear Layout | Two-stage small-module helical reduction |
| Power Range | ~80–150 kW traction motor (program-dependent |
| Gear Ratio | Overall i ≈ 8–12 (per OEM design) |
| Module Range | m 1.5–3.5 (helical) |
| Material | 18CrNiMo7-6 / similar case-hardening steels |
| Surface Hardness | Case-hardened, high hardness with tough core |
| Accuracy Grade | ISO 1328 Grade 4–5 |
Case Summary
By combining high-grade case-hardening steel, EV-oriented helical gear micro-geometry, and ISO Grade 4–5 gear accuracy, DD Gear helped this EV OEM:
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Reduce gear whine and tonal noise in the e-axle.
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Improve mesh efficiency and thermal behavior under real driving cycles.
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Validate a robust, series-production gearset for its new EV platform.
This approach is suitable for passenger EVs, hybrid drive units and light commercial EVs that demand high efficiency and low NVH.
Developing a new e-axle, motor reducer or auxiliary EV drive?
Contact DD Gear’s engineers to co-design small-module helical gears that balance efficiency, NVH and durability.
Medical Equipment Gear – Driving Accuracy in High-End Devices
A European medical device manufacturer needed precision gears for surgical robots and imaging equipment. The gears had to operate silently, reliably, and in some cases, be non-magnetic for MRI compatibility.
DDGear supplied custom small-module spur, worm, and plastic gears, manufactured with ISO Class 4 accuracy and materials suitable for medical standards. Rigorous inspection ensured each gear met the tight tolerances required for medical safety.
The result was improved accuracy in surgical applications, extended durability, and reduced machine downtime. The manufacturer gained stronger credibility in the medical sector and expanded its global market share.
Humanoid Robot Gear – Empowering Precision Robotics
A robotics startup in South Korea developing humanoid robots for healthcare and education needed gears that could deliver lifelike, silent movements. Standard gears created noise and backlash, making the robots appear less natural and less reliable for interaction.
DDGear designed precision small-module joint gears with micron-level tolerances and polished surfaces. These gears minimized backlash, reduced noise, and supported smooth torque transfer in elbow, wrist, and actuator assemblies.
With DDGear’s solution, the robots achieved 30% better movement stability and significantly lower noise. This improvement enhanced the robots’ acceptance in sensitive environments such as eldercare facilities, helping the startup secure new clients.
BLOG
Exploring The Science of Precision Gears
26 August,2025
Quality Control in Precision Gear Manufacturing
Introduction Quality control is the backbone of precision gear manufacturing. For gears used in demanding applications such as robotics and EVs, consistent reliability is ensured only through a rigorous quality management system spanning design, production, and delivery. 1.Design Stage Control From profile optimization to material selection, all design elements are evaluated to ensure manufacturability, durability, and performance. 2.Process Control Real-time monitoring, statistical process control (SPC), and automated inspections are applied throughout machining to minimize deviations and maintain tolerances. 3.Final Inspection Profile and lead measurement Noise and vibration testing Endurance and wear verification These checks ensure that every gear meets both functional and quality standards. 4.Certifications & Standards Precision gears comply with global standards such as ISO 1328, DIN, and AGMA. Certified systems like ISO 9001 and IATF 16949 ensure consistent quality for international customers. Conclusion Strict quality control guarantees not only the accuracy and durability of precision gears but also builds long-term customer trust. By adhering to the highest global standards, precision gear manufacturers support the reliability of next-generation robotics, EVs, and intelligent automation.
26 August,2025
Manufacturing Process of Precision Gears
Introduction Precision gears are not just the result of design excellence—they are the outcome of meticulous manufacturing. Every stage, from raw material to final inspection, determines the gear’s performance, durability, and accuracy. 1.Blank Preparation Gear blanks are typically made from forgings, castings, or bar stock. Material quality is the first guarantee of gear reliability. 2.Gear Cutting Hobbing: High efficiency, suitable for mass production. Shaping: Ideal for internal gears and complex profiles. Shaving: Improves tooth surface finish and precision. 3.Heat Treatment Processes such as carburizing, nitriding, and induction hardening are applied to enhance hardness, wear resistance, and durability. 4.Finishing Grinding: Achieves sub-micron tolerances. Polishing: Reduces roughness, minimizes noise. Finishing operations ensure smooth performance and precise accuracy. 5.Inspection & Testing Gears undergo profile and lead measurement, noise analysis, and endurance testing to guarantee consistent performance. Conclusion Manufacturing precision gears is a blend of science, engineering, and craftsmanship. By strictly controlling every process, manufacturers can deliver gears that meet the demanding standards of robotics, EVs, and industrial automation.
26 August,2025
Application Fields of Small-Module Precision Gears
Introduction In today’s high-tech industries, gears remain at the heart of power transmission. Small-module precision gears, with their compact size and high accuracy, have become essential components in robotics, electric vehicles, medical devices, and automated logistics. Robotics Small-module gears are widely used in humanoid robot joints, collaborative robots, and industrial robots. They provide high-precision rotation and torque transfer in limited spaces, ensuring smooth and repeatable movements. Electric Vehicles In EV drive motors and two-speed gearboxes, small-module gears enable high-speed operation with low noise, improving energy efficiency and driving comfort. Medical Devices Medical devices demand stability and quiet operation. Small-module gears are applied in surgical robots, imaging equipment, and precision delivery systems. Automation & AGVs In AGVs and automated warehousing, small-module gears power lifting mechanisms and steering wheels, ensuring efficient and reliable material handling. Conclusion Small-module precision gears are driving the future of industries, providing a solid transmission foundation for next-generation robots, EVs, and intelligent systems
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Faq’s
FREQUENTLY ASKED QUESTIONS
From robotics to electric vehicles, you'll find clear answers to every question here, and our engineering team will design, prototype, and deliver the perfect gear solution for you.
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Do you support small-volume custom orders?
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What industries are your precision gears mainly used in?
Our gears are widely applied in humanoid robots, electric vehicles, AGVs, industrial automation, and medical devices. We also provide tailored solutions for specific customer applications.
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How do you ensure the precision and quality of your gears?
We strictly follow international standards such as ISO 1328, DIN, and AGMA. With advanced CNC and gear grinding equipment, plus full inspection systems, we guarantee ≤ Grade 4 accuracy, long durability, and consistent performance.
IATF16949 Approved
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