Explore our CE-certified selection of manual override, quarter-turn, and multi-turn gearboxes designed for extreme industrial applications.
In the field of high-load power transmission, standard cylindrical worm gears often fail to meet the extreme torque demands of modern heavy industries. Double Enveloping Worm Gears (also known as globoid or cone worm gears) represent a quantum leap in engineering geometry. By designing the worm and the gear to wrap around each other, the configuration achieves a significantly larger contact area. Instead of the typical line-contact pattern of standard configurations, double enveloping gears yield a surface-contact area that is 3 to 4 times greater.
This dramatic increase in tooth contact distribution allows for extreme shock-load capabilities, outstanding mechanical efficiency, minimized backlash, and substantially reduced surface wear. As a certified CE Certification Double Enveloping Worm Gear Supplier, Stard-gears provides not only superior components but also the engineering assurance required for critical industrial integration.
Found in 1999, Locate in Suzhou Industrial Park. The plant covers 8900㎡，and the Office 2500㎡. Annual sales of $7,000,000, grew by 10%-20% per year. Have certificate of ISO9001. The annual production can reach 100,000 sets.
Stard-gears is a leading global provider specializing in valve control technology. Application scenarios for our products include oil, chemical, natural gas, nuclear, and water.
We are committed to product innovation, quality and reliable solutions to help our customers better manage their valves.
We are from Suzhou, China. The Yangtze River Delta region of China has a well-established and convenient supply chain, which ensures that our castings, machining capabilities, and spare parts procurement are advantageous at the same time. We are able to meet both fast delivery and better product quality.
Our more than 25 years of experience serving the industry means that our clients can rely on us to provide innovative, reliable and cost-effective solutions.
Strict alignment with CE Marking directives, ensuring our gearboxes comply with critical EU safety, environmental, and mechanical performance mandates.
Leveraging Suzhou's Yangtze River Delta network for highly competitive casting, heat treatment, and precision machining procurement with short lead times.
Providing custom ratios, dimensions, and metallurgy formulations to match extreme marine, buried pipe, and nuclear valve environments.
The international demand for high-torque actuators is seeing unprecedented growth due to deep-water exploration, high-pressure pipeline networks, and smart city infrastructure. Today, industrial operators cannot afford down-time; they require components that exhibit maximum torque density in small physical envelopes.
By wrapping the worm around the gear profile, the line of contact is perpendicular to the direction of sliding. This optimizes hydrodynamic lubrication, leading to a much lower coefficient of friction and a longer mechanical lifespan than conventional cylindrical layouts.
Stard-gears is a modern company integrating research & development, production, sales and trade.
Stard-gears had set up the goal of becoming the industry leader.
Last 10 years, our products have been exported to the United States, Italy, Germany, Mexico, Singapore, Japan and other countries.
Stard offers 9 series, about 80 varieties of gear operators.
Based on mission statement of “excellent reputation, best quality and perfect service” , the company would try best to serve customers all over the world.
Through 3D simulation, dynamic simulation, finite element analysis, etc., engineers can virtually verify the rationality of their designs of every new product before it is put into production, significantly shortening the design and development cycle of new products, ensuring the safety of the final products, and minimizing the costs.
Stard Automation runs a comprehensive ERP management system to ensure that the production schedule and progress of each order from each customer is clear at a glance. This system plays an important role in business operation and management. The real-time supervision and management are implemented throughout the production to improve efficiency.
The annual output value of the Suzhou plant can reach $9,000,000
The annual production can reach 100,000 sets
Double Enveloping Worm Gears are selected for operations where mechanical failure could lead to system shutdown or hazardous risks. Our gearboxes are configured for key target scenarios across multiple industries.
Operating steam containment isolation valves requires zero failure tolerance. Stard double enveloping gears guarantee rapid action and maintain structural integrity during extreme thermal expansion cycles.
Protected by multi-layer corrosion-resistant coatings, these gearboxes operate reliably in subsea environments, handling the torque requirements of large-diameter butterfly and ball valves under hydrostatic pressure.
Buried underground installations require long service intervals. The surface contact layout prevents localized tooth wear, preventing valve seizing during decades-long operational life.
To improve the inspection and testing process, Stard Automation has set up full-time QC posts at every stage of the manufacturing process from incoming materials to in-process control and to process finalization, ensuring that products are 100% qualified before shipment. Stard Automation owns a full range of advanced inspection and testing equipment to control the quality throughout the whole process from blank casting to finished products, which enables us to perform tests like the torque test and life cycle test.
As part of our commitment to valve control technology, Stard-gears is pursuing a structured research and development path to align our products with next-generation smart factories.
We are researching nickel-aluminum bronze alloys and advanced surface treatments to further minimize mechanical friction and improve wear resistance in marine environments.
Our future designs aim to embed vibration, temperature, and torque sensors within the gear housing, providing real-time data to support predictive maintenance systems.
By optimizing the envelope geometry, we are targeting a further 15% reduction in overall housing dimensions while maintaining the same output torque limits.
Key technical and compliance questions answered by our engineering and regulatory affairs department.
A standard cylindrical worm gear features a straight worm that meshes with a curved gear face, resulting in line contact. A double enveloping worm gear features an hourglass-shaped worm that wraps around the curved gear profile. This configuration increases the number of teeth in contact at any one time, distributing load forces over a larger area to support up to three times the torque capacity of cylindrical configurations.
CE Certification confirms that our gearboxes comply with European safety directives, including the Machinery Directive 2006/42/EC. This validation is essential for industrial equipment integrated into pressurized chemical pipelines, municipal systems, and power plants across the European Economic Area.
The contact area in double-enveloping systems promotes hydrodynamic lubrication, allowing an oil film to form between the teeth. This film minimizes direct metal-to-metal contact, lowering friction, reducing heat generation, and improving mechanical efficiency.
We use high-grade ductile iron or cast steel for the outer housings to ensure structural integrity. The worm shafts are typically manufactured from case-hardened alloy steel, and the worm gears are made of wear-resistant centrifugally cast bronze to optimize durability under continuous load.
For subterranean or marine installations, we provide customized gearboxes with IP68 environmental protection ratings. These units are fitted with high-integrity elastomer seals, filled with long-life synthetic lubricants, and finished with epoxy coatings to resist moisture and soil chemistry.
Further premium solutions and accessories supporting our core double enveloping transmission engineering.
