1. Project Introduction 

A coal mining client in Africa needs to equip their coal spiral conveying equipment with spiral rods. The equipment was initially purchased from a European company, but due to price increases and technical barriers, customers were unable to purchase parts from Europe, resulting in the equipment being unusable and seriously affecting production efficiency.

2. Project Solution

The technical personnel of Henan Zhengzhou Mining Machinery Co., Ltd need to analyze and verify the materials, dimensions, and processing accuracy requirements on the customer's drawings. And improved the technical requirements missing from the original drawings. To further ensure the quality of the design, three-dimensional simulation design is adopted for customer confirmation. It also provides support for the successful production in the later stage.     

The difficulty in production and processing mainly lies in:

1. The screw is variable in diameter, as evidenced by the variable diameter of both the helical blades and shaft. And the shaft is nearly 7m long, which requires a large amount of cutting of raw materials and is also very difficult to process.

2. The spiral blade has small teeth, and it is difficult to stretch the blade to ensure the size of the small teeth.

3. The wheels, shafts, and blades are all made of alloy steel, making welding difficult.

3. Project Implementation

Henan Zhengzhou Mining Machinery Co., Ltd. uses shaft material of 40Cr, blade material of 16Mn, and hub material of 40Cr. The shaft, blades, and hub all need to undergo quenching and tempering treatment to increase hardness, and the two ends of the hub are welded to make the equipment sturdy and durable.

The following optimization measures have been taken in the welding process of alloy steel:

1. Control welding parameters: Reasonably adjust welding current, voltage, and speed to avoid overheating or rapid cooling of the weld seam. If the welding current is too high, it will cause the weld seam to overheat, the grain size to become coarse, and reduce plasticity; If the current is too low, it will cause incomplete welding and fusion, forming stress concentration points and inducing cracks.

2. Adopting multi-layer and multi pass welding: dispersing welding heat and reducing residual stress.

3. Preheating and post heat treatment: For materials with a high tendency to harden, preheat before welding.

4. Optimize structural design: avoid dense arrangement of welds and reduce stress concentration; Change the sharp corner joint to a circular arc joint and increase the transition radius; Reasonably design assembly clearances, avoid forced assembly, and reduce assembly stress.

Henan Zhengzhou Mining Machinery Co., Ltd. possesses a professional technical team with expertise in ‌customized design‌ tailored to client requirements. The company effectively addresses critical operational challenges and delivers significant economic benefits