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260-9554
CAT
260-9554
In mining and large-scale construction, the slewing system is the key to achieving precise positioning and efficient operation. The Spline Board, also known as the slewing bearing ring gear or bull gear, is the core hub connecting the upper slewing platform and the lower travel chassis. It not only bears the weight of dozens or even hundreds of tons of the entire machine but also converts engine power into smooth rotational torque.
Designed specifically for mining drill rigs and large construction machinery, this product is manufactured from high-grade alloy steel using integral forging, precision machining, and quenching & tempering heat treatment. It delivers outstanding structural strength, wear resistance, and fatigue resistance. As a critical spare part for the slewing system, it directly guarantees the working efficiency and service life of mining and engineering machinery.
High-Grade Alloy Steel: Unlike ordinary carbon steel or cast steel, this product utilizes high-performance alloy structural steels such as 42CrMo, 35CrMo, or 50Mn2. Containing alloying elements like Chromium (Cr) and Molybdenum (Mo), these materials offer excellent hardenability and comprehensive mechanical properties, ensuring uniform strength and toughness even in thick cross-sections.
Integral Forging: The blank is formed via free forging or die forging. Forging not only compacts internal porosity but also allows metal flow lines to distribute continuously along the tooth profile. This fibrous structure provides exceptional shear resistance and impact toughness, preventing tooth breakage or cracking during travel on rough mining roads or drilling into hard rock.
High-Precision Tooth Profile: The teeth are processed via hobbing, shaping, and chamfering. We strictly control tooth profile errors (cumulative pitch error, tooth alignment error) to ensure the contact area is centered on the tooth height, avoiding early wear caused by misalignment. Accurate profiling ensures perfect meshing with the drive pinion, resulting in smooth, low-noise operation.
Quenching & Tempering Heat Treatment: The ring gear body undergoes quenching and tempering. This results in a base hardness of HB 240-280, providing high strength to carry heavy loads and good toughness to resist impact. The tooth surface can be induction hardened upon request to increase hardness to HRC 50-55, further enhancing wear resistance.
Surface Finish (Without Processing): Described as "Without Processing," the surface typically refers to the as-forged black finish or shot-blasted condition. This retains the original dense layer of the metal without the risk of coating peeling off, making it ideal for the harsh, collision-prone mining environment.
Excellent Load Bearing & Fatigue Resistance: Mining drill rigs generate massive overturning moments. Through optimized cross-section design and forging, this spline board withstands huge radial, axial, and overturning forces without fatigue fracture over millions of slewing cycles.
Precise Power Transmission: During complex excavator movements (e.g., slewing while curling the bucket), this product ensures lag-free and jerk-free power transmission. Smooth tooth surfaces reduce transmission shock, protecting the hydraulic motor and reducer.
Adaptability to Dusty Environments: Designed for high-dust conditions, the spline board reserves ample space for lubrication and seal installation. Combined with high-performance grease, it effectively blocks sand and grit intrusion, preventing abrasive wear.
As a Critical Spare Part, this spline board is widely used in:
Mining Drill Rig Slewing Platforms: Supporting the drill tower and performing 360-degree rotational positioning, enduring drilling reaction torque.
Large Excavators (30 tons+): Connecting the upper and lower carriages to enable full machine rotation.
Crawler Cranters: Supporting the boom and performing slewing operations.
Large Pavers & Milling Machines: Used for steering and positioning of working devices.
Ultrasonic Testing (UT): 100% ultrasonic inspection of the forging interior to ensure no flakes, cracks, inclusions, or other defects.
Hardness & Mechanical Property Testing: Inspecting Brinell hardness post-tempering and sampling for tensile and impact tests to verify material performance.
Tooth Profile & Lead Inspection: Using a Gear Measuring Center to inspect tooth profile, lead, and cumulative error, ensuring accuracy complies with DIN or GB standards.
Cleanliness & Alignment: Thoroughly clean the base mounting surface before installation. Ensure the contact surface between the spline board and the slewing support is flat and bolt holes are aligned.
Bolt Tightening: Must use high-strength bolts (Grade 10.9 or 12.9) and tighten strictly according to the specified torque and sequence (cross pattern).
