1. Introduction

The Main Shaft Assembly is the core component of a cone crusher, responsible for load bearing and motion transmission. It directly affects machine stability, service life, and crushing performance.
 

Under fine crushing conditions, the equipment operates under continuous high-frequency impact and cyclic loads, making the design and manufacturing quality of this assembly critical for long-term reliability.

2. Core Structure

Shaft

A machined component acting as the system backbone, responsible for:

• Transmitting eccentric motion.

• Supporting the crushing head.

• Withstanding bending and fatigue loads.

Material: 42CrMo alloy steel
Features: High strength, excellent fatigue resistance
→ Determines long-term structural integrity.

Head / Cone

A casting with precision machining, typically made of G20Mn5 steel.
Functions:

• Supporting the mantle.

• Transmitting crushing force.

• Absorbing impact.

→ Focused on impact and compressive resistance.

3. Assembly Process (Shrink Fit)

The shaft and head are connected using interference fit and thermal assembly:

• Head is heated and expands.

• Shaft is cooled and contracts.

• Combined to form a tight, high-strength connection.

Production practice:

• Heating and cooling are done simultaneously.

• Improves efficiency and ensures precision.

Advantages:

• No clearance.

• Strong bonding.

• Prevents loosening.

Even minor looseness may cause fretting, stress concentration, and early fatigue failure.

4. Working Conditions

The assembly operates under:

• Bending loads.

• Cyclic fatigue.

• Impact loads.

• Misalignment stress.

For CH series (fine crushing):

• Higher speed.

• Higher precision requirements.

• Greater stability demand.

→ Requires both strength and stability.

5. Machining Accuracy

Critical factors:

• Concentricity (runout)

• Surface roughness

• Fit tolerance

Small deviations can lead to uneven load, abnormal wear, vibration, and reduced lifespan, which are key differences between high-end and standard products.

6. CH vs CS Series

CS Series:

• Secondary crushing.

• Moderate conditions.

CH Series:

• Fine crushing.

• Flatter design.

• Stricter precision and stability requirements.

→ CH series demands higher main shaft assembly performance.

7. Conclusion

The main shaft assembly integrates material, design, assembly, and machining precision.
Its performance affects not only its own lifespan but also bearings, lubrication, vibration, and maintenance frequency.
→ A reliable assembly is essential for long-term stable operation.

Hyton provides one-stop wear and spare parts solution for GP&CH&CS series cone crushers. Here are the specific part numbers for the GP&CH&CS series main shaft assembly. Please refer to them：