7200 20CrMnTi Lockstitch Sewing Machine Gear Set for High-Speed Garment

Product Specification

7200 20CrMnTi Lockstitch Sewing Machine Gear Set for High-Speed Garment Production

7200 new high-speed lockstitch sewing machine gears are core transmission components for new computerized high-speed lockstitch machines like Brother S-7200A, mainly including upper shaft bevel gears, vertical shaft bevel gears, lower shaft spur gears, plastic driving gears, etc. Made of composite high-precision alloy steel and high-performance engineering plastic, they adapt to ultra-high-speed operation up to 5000~8000rpm, accurately transmitting power to control synchronous movement of needle bar, rotary hook and feed dog, ensuring stable stitches, low noise and long service life at high-speed sewing. Providing reliable transmission support for high-volume production scenarios of garments, home textiles, leather goods, etc.

 Product Features

• High-speed Adaptability: Support 5000~8000rpm continuous high-speed operation with stable transmission and no tooth skipping
• Composite Material: Metal gears (20CrMnTi/42CrMo) with high strength and wear resistance; plastic gears (POM/Nylon) for noise reduction and buffering
• High-precision Meshing: Tooth precision ISO 6~7 grade, backlash 0.02±0.1mm, accurate synchronization
• Set Design: Complete set of spur gears, bevel gears and shaft gears matching original 7200 model dimensions
• Low Noise & Vibration: Ground and polished tooth surfaces, noise ≤72dB at high speed
• Fatigue Resistance: Passed 10,000-hour life test, resistant to wear, pitting and breakage in continuous use
• Easy Installation: Original standard holes, keyways and positioning structure for direct replacement

Technical Parameter Table

Working Principle

• Motor power inputs to upper shaft; upper shaft bevel gear meshes 90° with upper vertical shaft bevel gear, converting horizontal rotation to vertical rotation
• Lower vertical shaft bevel gear reverses 90° again with lower shaft spur gear, driving lower shaft and rotary hook synchronously
• Lower shaft plastic gear drives feed shaft and thread take-up mechanism simultaneously, realizing strict timing synchronization of needle bar—rotary hook—feed dog
• Speed ratio (approx. 1:1~1:2) controlled by tooth number matching, ensuring precise motion matching of all mechanisms at max 8000rpm and uniform stitches
• Plastic gears buffer, absorb vibration and reduce noise; metal gears bear core torque transmission; composite collaboration achieves high-speed stable transmission

Main Applications

• Garment Industry: High-speed assembly line sewing for fashion, denim, knitwear, shirts
• Home Textile Industry: Mass high-speed processing of curtains, bedding, sofa covers
• Leather Goods Industry: High-speed sewing of medium-thick materials for bags, leather clothes, shoes
• Industrial Fabrics: Standard mass production of tents, luggage, safety belts
• Material Thickness: Light~medium heavy (0.1~6mm), max 8000 stitches/min
• Core Functions: High-speed transmission, precise direction change, timing synchronization, stable stitches, low noise operation

Product Advantages

• High-speed Stability: No shaking or tooth skipping at 8000rpm, stitch precision reaches industry A level
• Composite Durability: Metal hardened surface wear-resistant; plastic gears buffer; service life 30%+ higher than ordinary parts
• Ultra-low Noise: Precision ground teeth + plastic buffering, noise ≤72dB, improving workshop environment
• Precise Synchronization: Accurate backlash control, synchronization error <0.01mm between needle, hook and feed, perfect stitches
• Original Adaptation: 1:1 match of dimensions, holes, keyways for 7200 model, direct replacement without modification
• Easy Maintenance: Smooth lubrication, low dust accumulation, uniform wear, reducing downtime for replacement
• Cost-effective: Comparable to imported original parts, lower price, faster delivery, more convenient after-sales service

Production Process

Metal Gears (20CrMnTi/42CrMo)

• Raw Material Inspection → 2. Precision Forging/Cold Extrusion → 3. Normalizing Pre-treatment → 4. CNC Fine Turning (OD, ID, end faces, holes)
• Gear Hobbing/Shaping → 6. Carburizing & Quenching (HRC58~62) → 7. Low-temperature Tempering
• Bore/End Face Grinding → 9. Gear Grinding (ISO 6) → 10. Flaw Detection, Accuracy & Meshing Test
• Anti-rust Treatment, Laser Marking, Cleaning & Packaging

Plastic Gears (POM/Nylon 66)

• Raw Material Drying → 2. Precision Injection Molding → 3. Deburring & Aging Treatment → 4. CNC Milling (keyways, positioning holes)
• Tooth Finishing → 6. Dimensional, Hardness & Tension Test → 7. Cleaning, Anti-rust & Packaging

Why Choose us?

• 7-axis CNC Grinding: We adopt high-precision 7-axis CNC grinding machines, holding tolerances as tight as ±5μm, ensuring gears run quietly, smoothly and with outstanding durability.
• Strong technical expertise: Our core R&D team includes doctoral and master’s professionals specializing in spiral bevel gear technology, providing strong technical support for complex projects.
• Rigorous testing & high precision: All gears undergo 100% inspection with Gleason metrology systems. We can achieve DIN 6 grade accuracy with strict control over tooth profile and direction errors, keeping our quality at the industry-leading level.
• High transmission efficiency: Our gear designs support a single-stage reduction ratio of up to 300:1, with actual transmission efficiency reaching over 95%, greatly improving energy utilization.
• Excellent durability & cost efficiency: Our gears deliver 40% lower lifecycle cost and a failure rate below 0.5%, ensuring stable long-term operation and reduced maintenance costs.
• Fast response & short lead time: Supported by our digitalized production process, we are able to shorten the delivery cycle to only 20 working days, helping you accelerate project development and launch.
• Professional custom design capability: We provide fully customized gear solutions for applications requiring high-reduction, high-speed, heavy-load, low-noise, and special small-tooth profiles, based on your actual working conditions.