Heavy-Duty Spline Nut for Hydraulic Rock Drills This spline nut is engineered to transmit high torque in hydraulic rock drill drive systems, ensuring secure power transfer between splined shafts and components in extreme mining environments. Its robust 42CrMo4 alloy steel construction with induction hardening balances wear resistance (HRC50-55 surface) and impact absorption (HRC30-35 core), critical for reliability during continuous drilling.
Key Performance Attributes
Material & Durability:
42CrMo4 alloy steel achieves 1200MPa tensile strength, making it suitable for 9000N·m continuous torque applications. The induction-hardened spline surfaces (3-4mm depth) resist wear, extending service life by 40% compared to standard machined nuts .
8μm zinc plating (ASTM B633) provides 72-hour salt spray resistance (ASTM B117), protecting against corrosion in damp underground mines .
Precision & Compatibility:
28 splines (DIN 5480, module 3.0) with IT7 dimensional tolerance (ISO 286-1) ensure seamless meshing with splined shafts, reducing backlash and wear during high-torque operation. The M36x2 threaded end (ISO 7-1) enables secure locking with standard locknuts .
Ra 0.8μm surface finish minimizes friction between mating components, maintaining torque transmission efficiency in high-vibration environments .
Operational Reliability:
Rated for 10⁶ fatigue cycles under rated load (ISO 12044), it handles repetitive rotational forces from rock drill impact mechanisms. The -30°C to +100°C operating range ensures stability in cold mines and high-friction systems .
Applications
Hydraulic Rock Drills: Integral to drive systems, connecting splined shafts to gearboxes and rotary mechanisms.
Mining Equipment: Compatible with tunnel boring machines, quarry drills, and exploration rigs using splined drive systems.
