Hitachi ZX70 ZX80 ZX80LCK Swing Gearbox 4445648 4470057 Excavator Slewing Gearbox

The excavator swing gearbox, also known as the swing drive or slewing gearbox, is a critical component in hydraulic excavators. It enables the upper structure (house) of the excavator to rotate smoothly and efficiently, providing the machine with the necessary maneuverability for digging, lifting, and material handling operations.

This guide explores the working principle, construction, functions, appliions, and maintenance of the excavator swing gearbox, offering a comprehensive understanding of its role in heavy machinery.

Construction & Key Components

The swing gearbox consists of several essential parts:

(A) Hydraulic Motor

• Converts hydraulic energy into mechanical rotation.

• Common types: Axial piston motors, gerotor motors.

(B) Planetary Gear System

• Sun gear: Driven by the motor.

• Planet gears: Rotate around the sun gear, mounted on a carrier.

• Ring gear: Stationary or rotating, depending on design.

• Provides high torque output while maintaining compact size.

(C) Slewing Bearing (Swing Ring)

• Large-diameter ball or roller bearing that supports the excavator’s rotation.

• Can be internal gear type (common in modern excavators) or external gear type.

(D) Brake System

• Hydraulic disc brake (common in modern excavators).

• Mechanical brake (used in older models).

• Prevents free rotation when the machine is idle.

(E) Housing & Seals

• Cast iron or steel housing for durability.

• Oil seals and gaskets prevent leakage and contamination.

FAQ

• Q: When will you ship my order?
• A: Once we get confirmation of payment, we will try our best to ship orders within 24 hours.
• Q: Which shipping term you can supply?
• A: By sea, air, or by express ( DHL, FedEx, TNT, UPS, EMS)
• Q: How long does it take to my address?
• A: The Normal delivery time is 1-7 days, depending on which country you are in.