Crusher Wear Parts

Getting a jaw crusher to wear the ends off properly is similar to finding the proper match point on a set of cone crusher liners.

The jaw crusher was designed around an ideal closed side setting (C.S.S.). Deviation from that position diminishes the totality of jaw end wear. A hook forming on the stationary tells us that the crusher is being run at a closer C.S.S. than it was intended.

Whether that's right or wrong, it is what it is. We've altered and made special end details on many movable and stationary jaw dies, by either lengthening or shortening, to correct chronic match point issues. Length of the toggle plate and range of adjustment of the crusher affects the way the jaws align at the discharge end, as much as the way the material being crushed is reduced. If lower jaw mis-match occurs enough to affect output rate, try to correct with toggle plate and adjustment settings. If that doesn't fix things, a special length jaw can be made.

When we see an ideally worn set of lines with a utilization rate of 70 percent or a little higher, and which features a straight worn surface from the feed end to the discharge end, while producing at a uniform output rate -- we'll also see a crusher that got fed a uniformly sized range of in-feed and was run at an optimum discharge setting for the crusher model. Those are the most key factors in getting bowls and mantles to wear out right.

We've found the geometry involved goes like this: Getting the discharge match point in a cone crusher correct to its application is accomplished by aligning the discharge end of finer crushers, perpendicular to the sizing zones, near the most closed side. Coarser crushers that are run with larger discharge settings are aligned more to the vertical diameter of the B-liner. Cone crushers are designed to operate at a given setting and departures from that ideal number increasingly diminish the ability to obtain an ideal wear pattern.

The new generation of high-speed / high throw cone crushers adds another dimension to the ability to obtain an ideal discharge match point. Because of the increase in crusher head speed and eccentricity action, the ideal match point for a specific material is more difficult to identify. The ideal match point with these crushers may be at a point of alignment between the B-liner and mantle that is somewhere off the true closed side position. That means overlaying the "new gen" crushers at the closed side position for feed opening reasons will often result in discharge mismatch appearance.

When the worn mantle looks to have a hump at the big end, the B-liners discharge point is too short and is often the result of the crusher being run at a closer setting than its optimum (i.e., a 4 1/4' Symons standard being run at a .375" closed side setting, or C.S.S.) If the B-liner shows a hook at its discharge end, it's being run at too open a C.S.S. (i.e., a 4 1/4' Symons standard, being run at 1.250" C.S.S.) Either condition forms a "fence like" appearance, limiting best through-put rate. Running a cone crusher out of its ideal setting range will compromise liner performance.

By as many variations as there are available! The simplest response is to identify a tooth form with a pitch and depth that'll last the longest while also providing a constant output rate. The more wear metal that can be packed into the tooth shape, the longer it maintains that shape, as long as nothing detrimental results from that sectional shape.

Coarsely pitched, deep teeth will provide greater service life -- as long as the included flank angles aren't so steep as to trap, jamb or pack enough rock to plug the exit route for the crushed rock that breaks from the point pressure of the opposing tooth crowns. High toothed jaws are those in which the depth of tooth exceeds half the tooth pitch. Although shorter tooth depths (relative to the pitch, with a more open root detail) are not as long lasting, they excel in processing sticky material. Finer pitched round or sharp teeth produce a finer blend of finished product, though again while not as long lasting as the coarser high tooth designs.

The size of the crusher will also have a proportionate affect on the tooth pitch coarseness. Some examples: A fine tooth for a large 66 x 84 primary crusher would be spaced at 6 inches, while a coarse tooth would be spaced at 8 to 10 inches. A 2-inch pitch, like those found on a 10 x 24 crusher, would be too fine for the large model. The intermediate crushers in the 30 to 40 x 36 to 48 inch models have a broader range of tooth-spacing coarseness. It's not uncommon to see tooth forms from 3 to 8 inches applied to that range of crusher sizes.

We've been fortunate at Columbia Steel to have the foundry talent and pattern making abilities to provide about any tooth form required. The specialty tooth forms, such as the slab tooth, variable pitch, or flow groove types, are individual subjects of they're own.

A jaw crusher sized to deal with what you describe would be in the range of a 12 x 20 to 24. Sizing requirements for jaw crushers are commonly called out using the feed opening dimension first, then by the width dimension of the crushing cavity.

There have been several manufacturers of crushers in that size range. One of the more easily fitted was the Lippmann Engineering 12x24 capacity King model. It is no longer being made, though we still provide parts for the machines still in existence. The movable die is 28 long x 20 wide and is wedge held. The stationary is 24 long x 21.750” wide over-all, and is cheek plate held.

This is where I’m uncertain about understanding your question -- if you’re looking for a set of jaw dies that’ll fit you crusher, you’ll have to build the frame and pitman around what’s available (such as the dies for the Lippmann I described). Otherwise, you’ll be looking at considerable expense to make patterns for what you arrive at for your needed fitting dimensions.

To find something online, look at websites for OEM crusher manufacturers -- Metso, Pioneer-Kolberg, Lippmann or Cedarapids -- to see what size ranges of crushers they may be offering currently. They’ll likely not provide specific jaw die dimensional values in parts books. If you’re looking to build something around existing jaw dies, it’d be best to contact me direct to respond specifically to what your project requires.

Yes – someone from our well experienced (20 years minimum) technical staff will be in attendance all days of ConExpo – Steve Dolezal, Terry Whisel, or myself. We’ll be looking forward to seeing you there.