Excellent Performance Forging Drive Shaft for Roller Crusher Transmission System

Material selection

The transmission shaft needs to work for a long time under heavy and impact loads, so the material selection and heat treatment requirements are strict.

• The commonly used materials are high-quality medium carbon alloy steels such as 45 # steel, 40Cr, and 42CrMo, which have both strength and toughness and are not easily broken.

• It must undergo quenching and tempering treatment (quenching+high-temperature tempering), and some key parts will also undergo surface quenching to improve surface hardness and wear resistance, while ensuring core toughness and avoiding brittle fracture under impact.

Surface treatment

• Coating treatment - anti-corrosion

Applicable parts: the shaft body of the transmission shaft.

Process flow: degreasing → rust removal → phosphating → spraying primer (epoxy zinc rich primer) → spraying topcoat (polyurethane topcoat).

Processing effect: Isolate air and moisture, prevent the transmission shaft from rusting in dusty and humid environments, and the primer can also improve the adhesion of the topcoat.

• Plating treatment - reducing friction and preventing corrosion

Applicable parts: the mating surface between the journal and the bearing.

Common types:

Chrome plating: Surface hardness HRC60~65, good wear resistance and corrosion resistance, and can also repair slightly worn shaft necks (hard chrome plating layer thickness 0.05~0.1mm).

• Sandblasting/shot blasting treatment - surface cleaning and strengthening

Applicable parts: The overall surface of the transmission shaft (before heat treatment or painting).

Process effect:

• Clean the surface of oxide scale, rust, and oil stains to provide a clean surface for subsequent heat treatment or painting.

• Shot blasting treatment can also generate residual compressive stress on the surface, improving the fatigue resistance of the transmission shaft.

Structural characteristic

The transmission shaft of a roller crusher is usually a stepped shaft structure, with bearing installation sections, roller connection sections, and coupling (or gear) connection sections arranged in sequence on the shaft body. Both ends are fixed to the frame through heavy-duty bearings. The connection method between the transmission shaft and the roller is mostly key connection+expansion sleeve, which ensures the reliability of torque transmission and is easy to disassemble and maintain.

Quality inspection

After heat treatment, non-destructive testing (such as magnetic particle testing, ultrasonic testing) is required to check for defects such as cracks and slag inclusions, especially in stress concentration areas such as keyways, splines, and shaft shoulders.

Steel grade

High quality alloy steel listed as follows, such as 42CrMo, is usually selected and forged, quenched and tempered, and precision processed to have excellent fatigue resistance and wear resistance, meeting the high impact and high torque working requirements of crushers.