Worm - Worm Gear Pair Helical Tooth Meshing For Zigzag Sewing

Worm - Worm Gear Pair Helical Tooth Meshing For Zigzag Sewing

I. Design Principle —— Precision Logic of Spatial Non-Parallel Shaft Transmission
This is a worm-worm gear pair, with the core design centered around “90° spatial direction change + precise control of large transmission ratio”:
1.Tooth Profile and Meshing Mechanism
▶The worm has a helical tooth surface (similar to a screw, with a continuously surrounding tooth profile), and the worm gear has an arc tooth profile that envelopes the helical line of the worm. During meshing, the helical teeth of the worm “gradually cut into” the tooth grooves of the worm gear. The contact area is more than 3 times that of a spur gear, the transmission impact is reduced by 70%, and the noise is ≤ 72dB (meeting the silent demand of the sewing machine workshop).
▶The two shafts are spatially staggered at 90° (the worm is horizontal and the worm gear is vertical), replacing complex direction - changing mechanisms such as bevel gears, reducing the volume of the sewing machine head by 40%, and adapting to the compact layout of the zigzag sewing machine.
2.Transmission Ratio and Motion Conversion
It can achieve a large transmission ratio. After the high-speed rotation of the motor is decelerated by the worm-worm gear, the worm gear outputs low speed and high torque, accurately driving the needle swing mechanism to perform a “zigzag” reciprocating motion, ensuring the uniform swing frequency of the needle and the uniform density of the stitch.

II. Material Adaptation —— Functional Synergy of “Steel - Copper” Combination
The material selection of the worm (steel) and the worm gear (copper alloy) is a typical “triangle balance of strength - wear resistance - noise reduction”:
1.Worm (Driving Member)
Alloy structural steel is selected, and through carburizing and quenching + grinding, the tooth surface hardness reaches HRC58 - 62, and the wear resistant service life exceeds 12000 hours (capable of withstanding the impact load of high-frequency start-stop of the sewing machine); the core maintains toughness to avoid overload fracture.
2.Worm Gear (Driven Member)
ZCuSn10Pb1 tin bronze (or aluminum bronze) is adopted. The friction coefficient of the copper alloy is ≤0.15 (excellent self-lubricating property), which can reduce the wear of the worm by more than 50% during meshing; moreover, the elastic modulus of copper is low (only 1/3 of that of steel), which can absorb meshing vibration, reduce the risk of “thread skipping and thread breakage” of the sewing machine, and ensure the stitch accuracy is ≤± 0.1mm.

III. Functional Value —— “Stitch Heart” of the Zigzag Sewing Machine
In the zigzag sewing machine, this set of gear pairs undertakes the “core control unit for generating zigzag stitches” and dominates three key motions:
1.Needle Swing Motion Control
The uniform rotation of the worm-worm gear, through the eccentric wheel + connecting rod mechanism, converts the rotation of the worm gear into the left - right swing of the needle. When the transmission ratio i=20, the main shaft rotates 20 circles, and the needle completes 1 set of zigzag swings, adapting to the sewing needs of elastic fabrics such as underwear and bras.
2.Feeding Coordination and Matching
The worm gear shaft is linked with the feeding cam to control the forward and backward movement of the feeding teeth. The feeding direction is perpendicular to the swing of the needle (the needle swings left and right, and the feeding teeth feed forward and backward). The motion rhythms of the two are accurately synchronized to form a “zigzag” stitch and avoid fabric wrinkling.
3.Shuttle Synchronization Guarantee
It is linked with the shuttle driving mechanism to ensure that the rotation speed of the shuttle matches the puncture frequency of the needle, realizing the seamless connection of “needle exiting the hole - shuttle hooking the thread”, and the thread-skipping rate is ≤0.1%.

This set of worm - worm gear pairs, with the spatial non-parallel shaft transmission design, steel-copper functional materials, and precise stitch control, becomes the core carrier for generating “zigzag stitches” of the zigzag sewing machine. It not only meets the basic demands of light industrial machinery for “compactness, silence, and durability” but also adapts to the segmented scenarios of different fabrics and different stitches through customization. It is a typical example of the combination of “precise control and flexible production” in sewing machine transmission technology —— small gears drive a large industry and support the process innovation of industries such as clothing and underwear.

DINGSCO Precision Gear Solutions — Pioneering Force in Equipment Transmission

Core Advantages: Cutting-Edge Equipment × Digitalized Processes × Full-Cycle Services

As a leading precision gear manufacturer, DINGSCO specializes in customized production of micro high-precision spiral bevel gears and hypoid gears through our multiple CNC seven-axis five-linkage spiral bevel gear grinding/milling machines and Gleason spiral bevel cutter technology. With DIN 6 precision class (tooth profile error ≤ ±5μm), 95%+ transmission efficiency, and ultra-high reduction ratios, we deliver reliable transmission solutions for robotics, motor drives, new energy vehicles, and more.

Why Choose DINGSCO?
✅ High Precision: Achieving DIN 6 grade accuracy, leading the industry in controlling tooth profile errors.

✅ High Efficiency: With a single - stage reduction ratio of up to 300:1, and a transmission efficiency of over 95%.

✅ Durability: 40% lower lifecycle cost, <0.5% failure rate.
✅ Fast response: The digital process can shorten the delivery cycle to 20 working days.

Contact Us Soon for gear optimization proposals and 3D meshing simulations!

Our company was formerly known as Changsha Double Star Gear Industrial Co., Ltd, which was established in 1994. It is a directly affiliated university-run enterprise founded by Central South University Professor Zeng Tao, the leading expert on spiral bevel gears in China. It was later renamed as Changsha Senjie Gear Co., Ltd (abbreviated as "CSG") in 2016. CSG is a production R&D base specializing in professional design, reserch, manufacture and sales of high-quality small module spiral bevel gears and high reduction hypoid gears and cylindrical gears. In 2023, Hunan Dinghan New Material Technology Co., Ltd. was established as a specialized international export business department. CSG has strong scientific research and development capabilities and is also equipped a full set of advanced equipment including seven-axis five-linkage CNC spiral bevel gear grinding machines and gear milling machines. By making the best use of the scientific and technological achievements and equipment of the Gear Research Institute of Central South University, machanical processing, heat treatment and testing. We have developed high-quality products featuring high reduction, high speed, heavy load, low noise and less teeth for users.

With the quality policy of "scientific and technological innovation, quality first, being first-class firm and customer‘s satisfaction", we have won the trust of well-known domestic and abroad enterprises with stable and excellent quality. It is committed to be a pioneer of the industry of China's small-module spiral bevel gears, and is dedicated to providing service for any related industry requiring industrial robots, CNC turning and milling compound power tool turrets, industrial sewing machines, reducers, bicycles, power tools and aeromodelling. We sincerely look forward to your cooperation!