The continuous track system is a distinctive feature that allows bulldozers, excavators, tanks and other heavy construction or military equipment to traverse most terrains with amazing mobility. While the concept of tracks may seem simple at first glance, there is an intricate interplay of various components that work in unison to deliver superior traction and flotation. In this article, we examine the key components that make up the continuous track system – the track roller, track chain, track shoe and track link.

KOMATSU Excavator Track Roller PC300-5

Track Roller

As the name suggests, track rollers provide the rolling contact between the track and the underside of the vehicle. They are cylindrical in shape and mounted at intervals along both sides of the track frame. Typically made of hardened steel, track rollers must withstand heavy loads and impact loads while rolling.

Lubricated roller bearings within allow the rollers to rotate freely with minimal friction as the track moves. Their hardened exterior also resists wear from abrasion against the track components. Track rollers guide and support the track, distributing the vehicle weight evenly along its length for maximum traction and minimal ground pressure. Proper roller condition and alignment is critical for smooth track operation.

Track Chain

Track Chain

The track chain is the main load-bearing backbone member of the track system. It is composed of consecutive track links connected through either bushings or pin joints. Track chains for heavy machinery come in various designs like single grouser, double grouser or tri-link configurations for different applications.

Each track link has an aperture that passes around a sprocket tooth at the front or rear of the vehicle for tractive drive. This propels the endless loop of the track around the track rollers through constant motion of the drive sprocket. Track chains are made of hardened alloy steel for strength and durability under punishing field conditions over long service life.

track shoes

Track Shoe/Grouser

Track shoes are the removable ground-engaging components that provide traction. They are individually bolted or pinned to each track link. Most modern track shoes have extra projections called grousers or lugs that effectively engage with soil, rocks or other rough terrain for maximum grip.

Track shoes take the brunt of wear and are usually the first parts to require replacement. Hardened alloy steel and tungsten carbide inserts in the sole provide abrasion resistance. Shoe designs are optimized for different soil/surface types with varied lug configurations, width and material composition. Track shoes spread the vehicle weight for low ground pressure while their self-cleaning and self-sharpening properties maintain traction.

Track Link

As the primary load-bearing member of the track assembly, each track link is a rigid, closed-shape unit that connects multiple components together. The most common type is a single-piece, end-connected link with side plates joined by a top center guide.

Track links feature a large center aperture to engage sprocket teeth for power transmission from the drive sprocket. Their side walls support and guide the track rollers. Bottom recesses hold track shoes securely in position through attachment hardware. Grease fittings allow lubrication of link surfaces and inner cavities that keep links workable.

Different link designs exist optimized for weight carrying capacities, ground pressures and terrain conditions. Properly manufactured track links from hardened alloys can withstand years of cyclic stresses without failing structurally. The smooth articulation and flexible movement of interconnected track links enables the continuous track system to conform to uneven ground conditions.

In summary, continuous track vehicles leverage the co-ordinated function of each track system part to achieve unmatched flotation and traction capabilities across diverse work environments. Tuning the design, material selection and maintenance of track rollers, chains, shoes and links is vital to maximize heavy equipment performance, productivity and service life over tough operating cycles.