Sandvik CH and CS Series Cone Crushers — Technical Introduction, Wear Parts and Common Faults

1. What separates CH from CS

Sandvik's cone range splits into two families that look similar on the outside and behave differently in the chamber.

CH series (Hydrocone). Lower pivot point. The crushing force is taken lower on the main shaft, which lets the machine accept a coarser, less screened feed and still hold a reduction ratio. Typical position in a plant: secondary, behind a jaw, doing the bulk of the reduction. Models run CH420, CH430, CH440, CH540, CH550, CH660, then the i-series (CH830i / CH840i / CH860i / CH865i / CH870i / CH890i / CH895i) with automatic setting regulation built in.

CS series (higher pivot). The mantle is supported higher, so the chamber geometry gives a longer parallel zone and a better-shaped product. It wants a more consistent feed and is usually tertiary or quaternary. Models: CS420, CS430, CS440, CS660.

The practical consequence for parts: a CH machine running a feed that should have gone to a CS will wear liners in a pattern that looks like a manufacturing fault but is not. When a customer reports "the mantle wears on one side only", the first question is where the machine sits in the circuit, not what steel we supplied.

2. What actually wears

In order of money spent per year:

• Mantle and concave (bowl liner). Manganese, normally 18% Mn for granite and hard limestone, 22% Mn where the feed is abrasive and the chamber is coarse. Chamber designation runs from EC (extra coarse) through C, MC, M, MF, F to EF (extra fine). The letter is a promise about feed size — running an EF chamber with an MC feed is the fastest way to crack a liner.
• Burning ring and head nut. They hold the mantle on the head. Cheap parts, expensive failures: a mantle that lifts and spins destroys the head and the chamber in one shift.
• Eccentric and head bushings. Bronze. These are the parts that tell you the machine has been running hot or dry. Wear appears first as a bright band on one side, not as a failure.
• Dust seal (and the collar around it). Protects the oil from the quarry. Every gram of grit that passes it ends up lapping the bushings.
• Pinion and bevel gear. Wear shows as noise under load before it shows as damage. Backlash and contact pattern are what to check, not tooth thickness alone.
• Spider/arm liners, top and bottom shell liners. Protect cast iron with cheap steel.

3. Chamber and liner selection

The chamber is chosen for the feed, not for the product. Two rules that hold across the range:

1. The feed must be screened. A cone crusher is not a jaw. Slabby or oversize material bridges, the chamber starves and fills alternately, and the liner wears in a wave pattern that no steel grade can survive.

1. The reduction ratio per stage has a ceiling. Trying to take 300 mm down to 10 mm in one cone produces a poor shape and a short liner life. Two stages with correct chambers cost less per tonne than one stage with an oversized drive.

On the parts side, the number that matters is the part number on the old liner plus the machine serial. Sandvik revised chamber profiles across production years; two liners that carry the same "CH440 mantle" label can differ in height and angle. We confirm against the drawing before anything is cast.

4. Common faults, symptoms and what they mean

Oil temperature climbing

Symptom: return oil runs hot after two or three hours, then stabilises high; eventually the machine trips on the oil temperature switch.

Causes, in the order worth checking: low oil level or a restricted suction strainer; a worn dust seal letting fines into the oil (the oil turns grey, then black); a cooler that is fouled on the water side; the wrong oil viscosity for ambient temperature. High oil temperature is a symptom of contamination far more often than of a failed pump.

Bushing burning (eccentric or head)

Symptom: the machine stops, the oil smells burnt, and the bushing shows a bright, smeared band on one side.

Two root causes: starvation (pump, filter, blocked oil gallery) or overload (tramp iron, feed too fine, feed segregation, discharge opening too small, feed too wet). Overload on a Hydrocone shows first as a jump in the adjusting ring and a spike in current, then as heat. If the eccentric bushing is burning repeatedly, look at the feed arrangement before replacing anything.

Mantle lifting or spinning

Symptom: the closed side setting drifts, the product gets coarser, and the wear pattern on the concave stops being a ring and becomes a spiral.

Cause is almost always the bedding: mantle installed dry, backing compound mixed wrong, or the head nut torqued without the burning ring doing its job. The burning ring locks a correctly seated mantle; it cannot seat a loose one.

CSS drift under load

Symptom: the setting creeps open during a shift and has to be trimmed back.

On the i-series this shows up as a Hydroset/Hydroset Plus fault code or an adjusting cylinder that will not hold pressure. On the older machines, check the clamping and adjustment cylinders for internal leakage and the pressure accumulator charge before blaming the control system.

Noise from the drive

Symptom: a knocking or whine that appears under load and disappears when the chamber is empty.

Pinion/bevel contact pattern and backlash. Also worth checking the countershaft bearing and, on belt-driven machines, the sheave alignment — a misaligned drive loads the pinion unevenly and the gear wears on one flank.

5. Maintenance that pays

• Weekly: oil level, oil pressure, return oil temperature trend, dust seal condition (look at the seal, not just the oil), head nut torque mark.
• Monthly: oil sample (iron and silicon content tell you more than the colour), backlash check, accumulator pre-charge, liner wear measurement at fixed points — measure, do not eyeball.
• Every liner change: check the head seating surface and the burning ring groove; re-torque the head nut after the first eight hours of running a new mantle.

Two numbers worth writing on the wall next to the machine: the closed side setting and the ammeter reading at normal load. Every fault on this list announces itself as a deviation from those two before it announces itself as a breakdown.

6. Matching parts to the machine

For CH and CS machines we work from three things: the part number on the worn component, the machine serial number, and photographs of the old part with a tape measure across the critical dimension. Sandvik part numbers are precise but not always unique across revisions — the serial is what resolves the ambiguity.

If a part cannot be confirmed against the drawing, we say so. A liner that is "close" costs more than a liner that arrives late.