This is a heavy-duty forged gear shaft (pinion shaft), a core high-precision transmission component designed for large-scale rotary equipment such as cement ball mills, rotary kilns, rod mills, and mining grinding systems. It is an integral forged part that meshes with the large girth gear to transmit high torque, driving the mill or kiln cylinder to rotate stably under extreme heavy-load conditions.

Hardness after heat treatment: HB180-230

Surface hardness shall reach HRC57-61 with carburizing treatment.

Produced per drawing dimensions, and production can only start after user confirmation.

Drawing No.: OL 233236

Detailed technical requirements and dimensions refer to attached drawing OL 233236.

Key Functions

- Transmits high driving torque from the gear reducer to the main girth gear

- Drives the ball mill / rotary kiln cylinder for continuous low-speed rotation

- Withstands heavy radial/axial loads, impact, and cyclic fatigue stress

- Ensures precise, smooth meshing with the large gear ring to minimize vibration

- Maintains long-term reliable operation in high-temperature, high-dust industrial environments

Material & Manufacturing Process

Material

Standard Material: 42CrMo / 35CrMo alloy structural steel (for heavy-duty applications)

Optional Material: 40Cr, 20CrMnTi, or customized high-strength alloy steel per customer requirements

Material Features: High strength, excellent toughness, good hardenability, and outstanding fatigue resistance

Manufacturing Process

1. Integral Forging: One-piece forging to eliminate internal defects, enhance mechanical strength and impact resistance

2. Heat Treatment:

- Quenching and tempering (Q&T) for overall hardness (HB 260–300) and toughness

- High-frequency surface hardening / carburizing hardening on gear teeth (HRC 55–62) for superior wear resistance

- Stress relief annealing to prevent deformation

3. Precision Machining:

- Precision hobbing and grinding of gear teeth (accuracy grade: GB/T 10095 6–8 / ISO 1328 6–8)

- High-precision grinding of shaft journals, keyways, and threads

- Strict concentricity and runout control to ensure smooth meshing

4. Quality Inspection:

- UT (Ultrasonic Testing) / MT (Magnetic Particle Testing) for internal and surface defects

- Dimensional inspection, hardness testing, and material certification

Structural Features

- Integral Forged Structure: One-piece design for maximum rigidity and load-bearing capacity

- Large Modulus Gear Teeth: Optimized tooth profile for heavy-load transmission, low noise, and long service life

- Precision Machined Shaft Journals: With keyways, threaded ends, or mounting shoulders for bearing and coupling installation

- High Roundness & Concentricity: Minimizes vibration and ensures stable equipment operation

- Customizable Design: Fully customizable per customer drawings (module, number of teeth, shaft diameter, length, etc.)

Application Scope

- Cement ball mills, rod mills, and raw material mills

- Cement rotary kilns, lime kilns, and metallurgical rotary kilns

- Large industrial reducers and gearboxes

- Mining grinding equipment, dryers, and rotary coolers

- Other heavy-duty rotary drive systems