The spring cone crusher is the workhorse of medium and fine crushing in aggregate and mining plants. Before the machine can be operated, maintained or troubleshot effectively, you need to know what is inside it and how each component works together. This guide uses the PY1750 spring cone crusher as a reference and covers its basic structure, gyratory working principle, discharge opening adjustment, iron-passing safety device, and the common faults and wear part lifespans every operator should know.
Basic Structure of the Spring Cone Crusher
The working mechanism of a spring cone crusher consists of two crushing members: a movable cone lined with manganese steel and a fixed cone (also called the adjustment ring). The movable cone is press-fitted onto the main shaft (vertical shaft), and one end of the main shaft inserts into the tapered bore of the eccentric bushing. A bronze bushing or an Mc6 nylon bushing is installed inside the tapered bore of the eccentric bushing.
To guarantee the gyratory movement, the lower surface of the movable cone is machined spherical and supported on spherical bearings. The total weight of the movable cone and main shaft is borne by the spherical bearings and the machine frame.
- A proven innovation: replacing the bronze bushing with a nylon bushing inside the eccentric bushing of a cone crusher is a successful technical innovation. Production practice shows that the nylon bushing offers wear resistance, fatigue resistance, long service life, light weight and low cost - a promising alternative material.
Working Principle: Gyratory Crushing Motion
When the eccentric bushing rotates, it drives the movable cone to perform a gyratory motion around the axis of the crusher. The motor drives the transmission shaft, and the cone assembly swings around a fixed point through the eccentric sleeve.
The crushing wall (mantle) moves close to and then away from the fixed rolling mortar wall (concave). Material entering the crushing chamber is crushed by impact, squeezing and bending. Once the material reaches the desired particle size, it falls and is discharged from the bottom of the machine.
Discharge Opening Adjustment and Locking Mechanism
The adjustment and locking mechanisms are practically part of the fixed cone, mainly composed of the adjustment ring, support ring, lock nut, pushing oil cylinder and locking oil cylinders.
- The support ring is mounted on the upper part of the frame and tightly attached to it via the springs surrounding the crusher.
- Locking oil cylinders and pistons are fitted on top of the support ring - 12 cylinders for the 1750-type cone crusher and 16 cylinders for the 2200-type.
- Serrated threads are machined on the contact surfaces between the support ring and the adjustment ring. Two pairs of shifting claws and one pair of pushing oil cylinders are installed on the support ring.
How adjustment works: during operation, high-pressure oil enters the locking cylinder and lifts the piston, slightly jacking the lock nut and adjustment ring so that their serrated threads fit closely along the inclined surfaces. To adjust the discharge opening, the locking cylinder is unloaded to release the serrated threads, then the hydraulic system actuates the pushing cylinder, driving the adjustment ring to rotate clockwise or counterclockwise. Driven by the serrated-thread transmission, the fixed cone rises or falls, changing the discharge opening size.
Safety Device: Iron Passing Protection
The safety device is a circle of springs installed around the frame. When uncrushable material (such as tramp iron) enters the crushing chamber, the support ring and adjustment ring seated on the springs are forced upward, compressing the springs. The gap between the movable cone and the fixed cone enlarges, the discharge opening widens, and the uncrushable object is discharged before it can damage components. Afterward, the support ring and adjustment ring return to their original positions under spring force, and crushing resumes automatically.
Common Faults of the Medium-Fine Cone Crusher (Quick Reference)
| Equipment Fault | Cause | Elimination Method |
|---|---|---|
| Uneven rotation of transmission shaft; loud knocking noise, then the pulley rotates while the movable cone stays static | Bevel gear tooth wear caused by assembly defects or excessive axial clearance; damaged key of pulley or gear; main shaft fracture caused by uncrushable objects | Stop the crusher; replace the gear and calibrate meshing clearance; replace the key; replace the main shaft and strengthen iron-removal work |
| Severe crusher vibration; movable cone rotates rapidly | Poor lubrication between main shaft and bushing; sinking movable cone or damaged spherical bearing; insufficient clearance of tapered bushing | Stop the crusher; locate and eliminate the root causes |
| Vibration during crusher operation | Insufficient spring pressure or rigidity; feed too fine or sticky; uneven feeding or overfeeding | Tighten or replace the springs; adjust crusher feeding |
| Crusher lifts upward with a heavy knocking sound, then returns to normal operation | Uncrushable material entered the crushing chamber; may cause main shaft fracture | Strengthen iron-removal work |
| Audible cracking noise during crushing or idling | Loose screw or broken lifting lugs of the cone liner; impact caused by an out-of-round cone liner | Stop the crusher; check screw tightness and zinc-casting layer peeling; replace nuts and lifting lugs; inspect liner roundness during installation and machine if necessary |
| Screws jump out of frame flange holes and springs | Damaged frame tension nut | Shut down the machine and replace the screws |
| Oversize lumps in crushed products | Worn movable cone liner | Lower the fixed cone to narrow the discharge opening gap |
| No water flows into the water-seal device | Incorrect water supply pipe for the water-seal device | Shut down the machine; find and eliminate the water supply terminal faults |
Main Wearing Parts: Service Life and Minimum Stock
| Wearing Part | Material | Service Life (Months) | Minimum Stock Quantity |
|---|---|---|---|
| Movable cone liner | Manganese steel | 6 | 2 sets |
| Fixed cone liner | Manganese steel | 6 | 2 sets |
| Eccentric bushing liner | Bronze | 18–24 | 1 pc |
| Bevel gear | High-quality steel | 24–36 | 1 pc |
| Eccentric bushing | Carbon steel | 4–8 | 1 pc |
| Transmission shaft | High-quality steel | 24–36 | 2 sets |
| Spherical bushing | Bronze | 4–8 | 1 pc |
| Main shaft | High-quality steel | [confirm] | 1 pc |
Keeping the minimum stock quantities listed above ensures you can replace worn parts without long downtime. Service life figures are reference values for typical medium-hard ore conditions; actual life varies with feed material, moisture and operating practices.
Maintenance Tips for Spring Cone Crushers
- Replace liners on schedule. Movable and fixed cone liners are the fastest-wearing parts (about 6 months under normal conditions). Replacing them in time prevents damage to the main body; keep 2 sets in stock.
- Keep spring tension correct. Too loose - the machine vibrates; too tight - the spring loses its protection capability.
- Check lubrication. Poor lubrication between the main shaft and bushing is a direct cause of severe vibration; follow the wear cycles for bushing replacement.
- Verify the water-seal supply. No water flow into the water-seal device allows dust into internal components - check the water supply pipe regularly.
- Strengthen iron removal. Uncrushable metal entering the chamber is the leading cause of main shaft fracture and liner lug damage. Even though the spring device passes tramp through, repeated events damage the machine.
- Consider nylon bushings. Where suitable, the Mc6 nylon bushing offers wear resistance, fatigue resistance, long service life, light weight and lower cost than bronze.
Spring Cone Crusher FAQ
1. What is the difference between a spring cone crusher and a gyratory crusher?
- The structures are generally similar, with partial differences. The spring cone crusher is designed specifically for medium and fine crushing, and its spring system doubles as both frame mounting and overload protection - when uncrushable material enters, the springs yield and the discharge opening widens automatically.
2. How do you adjust the discharge opening of a spring cone crusher?
- Unload the locking cylinders to release the serrated threads, then the hydraulic pushing cylinder rotates the adjustment ring clockwise or counterclockwise. Through the serrated-thread transmission, the fixed cone rises or falls and the discharge opening size changes.
3. How does the iron-passing safety device work?
- A circle of springs around the frame holds the support ring and adjustment ring. When uncrushable material enters the crushing chamber, the rings are forced upward, compressing the springs; the discharge opening widens to eject the object, then the springs return the parts to their original position.
4. What are the main wear parts of a cone crusher and how long do they last?
- The manganese steel movable and fixed cone liners last about 6 months (keep 2 sets each); the eccentric bushing liner (bronze) 18–24 months; the bevel gear 24–36 months; the spherical bushing 4–8 months. Exact life depends on feed and operating conditions.
5. Is a nylon bushing better than a bronze bushing?
- The Mc6 nylon bushing has proven wear resistance, fatigue resistance, long service life, light weight and low cost, making it a successful alternative to bronze in the eccentric bushing of cone crushers.
6. Why is iron removal so important for cone crushers?
- Uncrushable metal is the main cause of main shaft fracture, liner lug damage and gear/key damage. The spring safety device can pass tramp through, but repeated iron events shorten component life and increase downtime - good iron removal upstream is the cheapest protection.
