Crusher Comparison

Cone Crusher Motion Model

The diagram to the right shows how the position of the head pivot affects the crushing process and efficiency.

All known cone and gyratory crushers fit this model. Early gyratory crushers had their pivot centres located well below the head while the modern cone crusher has the pivot center above the top of the head.

Both of these crushers have the common disadvantage that as the head swishes to the closed side, a gap bigger than the required “closed” size opens on the opposite side of the head, allowing “oversize” to pass through.

Moving the pivot point closer to the head reduced this at the expense of effective throughput. The Wescone head design is substantially different. It combines a central pivot with a two-sided head, eliminating many of the problems associated with existing models.

As the head swishes to the closed side in the upper zone, the opposite lower zone closes off, further crushing the feed and minimizing the escape of the “oversize” material.

Head Arrangement Controls Throughput

Figure 1 compares the effective throughput of similarly sized machines, showing that the net throughput will decrease substantially with movement of the pivot point.

While it might have been previously believed that this graph was continuous, test with the Wescone have established a previously undiscovered window of high throughput.

To help understand the problems with existing crusher designs the associated sketches (figure 2) are provided to compare similarly proportioned machines, each with 300 gape, 30 stroke (10:1) and 10mm CCS.

Figure 2 compares the theoretical model with an early gyratory crusher (with the pivot below the head), a modern cone crusher (with the pivot above the head) and a Wescone.

In the theoretical case, the small opening prevents efficient discharge. With the cone and gyratory crusher, this is circumvented by moving the pivot point out, at the expense of promoting oversize. The second stage of the Wescone permits quick exit of crushed products without oversize.