1. Product Positioning
The SD320 transmission planetary gear is a core load-bearing component for wheel-side transmission in transmissions of bulldozers, wheel loaders and construction machinery. It is a flagship specialized, sophisticated, distinctive and innovative product of Hengji Group. This single product category holds 25 gear patents including 8 invention patents, with a gear surface machining precision of Grade 6, surpassing the industry's general Grade 8 standard.
2. Materials & Manufacturing Processes
Base Material: 42CrMo alloy forged steel, integrally forged blanks free of pores and cracks, delivering far higher load capacity than ordinary 45# steel gears.
Processing Flow: CNC rough turning → gear hobbing → carburizing and quenching → low-temperature tempering → precision gear grinding → inner hole precision honing → non-destructive flaw detection
Heat Treatment: Carbonitriding hardening process. The gear surface hardness reaches HRC58–62, while the core retains sufficient toughness to resist tooth breakage and pitting corrosion under heavy loads.
3. Core Performance Advantages
Smooth Power Transmission: Precision ground straight teeth with minimal tooth pitch error, cutting transmission noise by 30%.
Extended Service Life: Wear resistance lifespan under heavy-load working conditions increased by 45% compared with standard gears, lowering equipment maintenance frequency.
Wide Compatibility: Compatible with transmissions for SD320 bulldozers, various loaders, motor graders and engineering winches; custom non-standard products available based on customer drawings and samples.
Full In-House Industrial Chain: Hengji operates self-owned casting-forging, heat treatment and gear grinding workshops with no outsourced manufacturing, ensuring stable lead times and consistent quality control.
4. Supporting & Market Layout
Domestic Direct Supply: We supply major construction machinery manufacturers including Shantui, Sany, Zoomlion, LiuGong and Komatsu.
Export Business: Mass shipments to Saudi Arabia, South Africa, Tanzania, Algeria, Russia and other markets. The products hold CE export certification and original factory inspection reports, supporting large-volume OEM supporting services.
5. Applicable Equipment
Planetary reduction mechanisms inside transmissions for bulldozers, wheel loaders, small road rollers, mining engineering winches and large agricultural tractors.
