Product Overview

The Carrier Roller, also known as Top Roller or Upper Roller, is mounted above the track frame of the Hitachi ZX870 crawler excavator.

For an 80-ton class excavator, the undercarriage system operates under extremely high dynamic loads during excavation, travelling and mining operations. The carrier roller supports the upper track chain, maintains chain alignment and reduces friction between moving undercarriage components.

A worn or damaged carrier roller may cause:

• Excessive track chain vibration
• Abnormal travelling noise
• Increased track resistance
• Uneven chain movement
• Accelerated wear of track links and bushings
• Increased operating downtime

Our ZX870 carrier rollers are manufactured with professional undercarriage production technology and provide a reliable aftermarket replacement solution for mining contractors, equipment dealers and repair workshops.

Key Features & Benefits

Heavy-Duty Mining Application

Designed for:

Hitachi ZX870 / ZX870-5G

Suitable for:

• Open-pit mining
• Quarry operations
• Heavy construction
• Large-scale earthmoving

High-Strength Alloy Steel

Manufactured from:

40Mn2 Alloy Steel

Benefits:

• High load-bearing capability
• Excellent impact resistance
• Strong fatigue resistance
• Superior wear performance
• Extended service life

Advanced Heat Treatment

The roller working surface is processed with controlled induction hardening.

Typical specification:

• Surface hardness: HRC 52-58
• Hardening depth: 10mm-15mm

Provides improved resistance against continuous heavy loading and abrasive mining environments.

Heavy-Duty Floating Seal System

Equipped with:

• Heavy-duty floating oil seals
• Wear-resistant bushings
• Lifetime internal lubrication

The sealing system helps prevent lubricant leakage and protects internal components from mud, dust and water contamination.

OEM-Style Direct Replacement

Manufactured according to OEM-style dimensions:

• Roller diameter
• Shaft dimensions
• Mounting dimensions
• Track chain contact surface

Designed for direct replacement after confirming correct specifications.

Technical Specifications