Crawler Excavator

A crawler excavator is a construction vehicle designed to dig or move large objects. Crawler excavators are heavy equipment composed of a boom or backhoe, bucket and cab on a rotating platform (known as a house). The house sits atop an undercarriage with tracks or wheels. All movement and functions of the crawler excavator are achieved through the use of hydraulic fluid, be it with rams or motors. The operator sits inside a small cab attached to the base and controls the arm.

Crawler excavators are used in many ways:
Digging of trenches, holes, foundations;
Material handling, earth moving;
Brush cutting with hydraulic attachments;
Demolition;
Dredging project;
General grading or landscaping;
Heavy lift, e.g. lifting and placing of pipes;
Driving piles, in conjunction with a pile driver.

Crawler excavators are available in a wide range of sizes and capacities. The smaller ones are called mini or compact crawler excavators. Some small crawler excavators have zero swing and are suitable for work in narrow site.

The engine in a crawler excavator is primarily used to drive hydraulic pumps. There are usually 3 pumps. The two main pumps are used to supply oil at up to 5000 psi for the rams, slew motor, track motors, and accessories. The third pump is for pilot control. This is a lower pressure (700 psi) circuit used for the control of the spool valves, which allows for a reduced effort required when operating the controls.

The basic components of a crawler excavator include, the undercarriage which has the blade (if fitted), tracks, track frame, and final drives which have a hydraulic motor and gearing providing the drive to the individual tracks. The house including the operators cab, counterweight, engine, fuel and hydraulic oil tanks attaches by way of a centre pin to the undercarriage, enabling the machine to slew 360° unhindered.

The main boom attaches to the house. It can be one of 3 different configurations. Most are mono booms, which have no movement apart from straight up and down. Some others have a knuckle boom which can also move left and right in line with the machine. The other option is a hinge at the base of the boom that allows it to hydraulically pivot up to 180° independent to the house, however, this is generally available to compact crawler excavators.

The stick or dipper arm is attached to the end of the boom, which offers the digging force required to pull the bucket through the ground. The stick length is optional depending whether reach (longer stick) or break-out power (shorter stick) is required.

On the end of the stick is usually a bucket. A wide, large capacity (mud) bucket with a straight cutting edge is used for cleanup and leveling or where the material to be dug is soft, and teeth are not required. A general purpose (GP) bucket is generally smaller, stronger, and has hardened side cutters and teeth used to break through hard ground and rocks. Buckets come in numerous shapes and sizes for various applications. Many other attachments are available to be attached to the crawler excavator for boring, ripping, crushing, cutting, lifting, and so on.

Sinoway supplies all kinds of crawler excavators with operation weight from 3.5 ton to 120 ton, crawler and wheel drive.