Double Toggle Jaw Crusher

The Double Toggle Jaw Crusher: Robustness and Power for Demanding Applications

In the rugged world of primary crushing within mining, quarrying, and aggregate processing, few machines embody raw power and mechanical reliability quite like the Double Toggle Jaw Crusher. While its single-toggle counterpart often dominates discussions due to its prevalence in modern mobile plants and simpler design, the double toggle crusher remains an indispensable workhorse for specific high-demand scenarios where brute force and reduced wear are paramount.

Understanding the Mechanism: A Study in Leverage

The defining characteristic lies within its name and mechanism:

1. The “Double Toggle” Principle: Unlike a single-toggle crusher where one end of the moving jaw is driven directly by an eccentric shaft while the other pivots freely at a fixed point, a double-toggle crusher features two toggle plates.
2. Components & Motion:

Fixed Jaw: Anchored rigidly to the crusher frame.
Moving Jaw: Suspended at its top by an eccentric shaft mounted on bearings near the top of the frame.
Toggle Plates: One connects between the bottom of the moving jaw and a fixed point at the rear of the frame (the back toggle seat). The other connects between a point near the bottom of the moving jaw and a swinging lever called the pitman arm (or simply pitman), which is directly actuated by the eccentric shaft.
Eccentric Shaft: Positioned near or above the top of the moving jaw.
3. The Crushing Action: As the eccentric shaft rotates:
It imparts an elliptical motion primarily to the top of the pitman arm.
This motion forces both toggle plates into action.
The linkage system translates this into a predominantly elliptical motion at both ends of the moving jaw.
Crucially, at any point in its stroke (especially near discharge), every point on the moving jaw follows an elliptical path that has a significant vertical component relative to its opposing point on the fixed jaw liner.

Distinct Advantages: Where It Excels

This unique kinematic design translates into several significant advantages:

1. Superior Crushing Force & Stroke Control: The leverage generated by two toggle plates allows double-toggle crushers to exert significantly higher crushing forces compared to single-toggle machines of comparable size. This makes them exceptionally effective against extremely hard or tough feed materials like granite or trap