The housing material for lawnmower gearboxes typically consists of die-cast aluminum alloy, representing the most common structural choice. The advantages of aluminum alloy lie in its lightweight nature and excellent heat dissipation properties; furthermore, it possesses sufficient strength and corrosion resistance to withstand the rigors of prolonged outdoor use. Some entry-to-mid-range models may utilize reinforced engineering plastics for their housings to reduce manufacturing costs and overall unit weight; however, in terms of overall stability-particularly when subjected to impact or sustained high-load operation-these plastic materials generally fall short of their metal counterparts.
The core internal transmission components of the gearbox are typically fabricated from high-strength alloy steel-specifically carburizing steels such as 20CrMnTi. Following a carburizing and quenching heat treatment, these components exhibit high surface hardness and exceptional wear resistance while retaining sufficient internal toughness, enabling them to effectively withstand the wear and impact associated with frequent gear meshing. The bearings are predominantly manufactured from bearing steel (e.g., GCr15) to ensure stability and longevity during high-speed operation. Additionally, the gear surfaces typically undergo precision grinding to minimize noise and enhance transmission efficiency, thereby ensuring the entire gearbox maintains reliable performance even within challenging grassland environments.