Multi-cylinder Hydraulic Cone Crusher

Upper Frame: A cast steel (ZG270-500) structure with a cylindrical shape, supporting the fixed cone and adjustment mechanism. It features a flange at the top for connecting the feeding hopper and radial reinforcing ribs (thickness 30–80 mm) to withstand crushing forces.

Lower Frame: A heavy-duty cast steel (ZG35CrMo) base that houses the eccentric shaft sleeve, main shaft bearing, and hydraulic cylinder system. It is bolted to the foundation to ensure stability during operation and is equipped with oil passages for lubrication and cooling.

Moving Cone: A conical component with a wear-resistant liner (high-chromium cast iron Cr20 or manganese steel ZGMn13) attached via zinc alloy casting. The cone body is forged from 42CrMo alloy steel, with a spherical bottom that fits into the main shaft’s spherical bearing to ensure flexible oscillation.

Fixed Cone (Concave): A segmented annular liner (3–6 segments) made of high-chromium cast iron, mounted on the inner wall of the upper frame. Each segment is designed with a specific cavity profile (angle, depth) to control the crushing process and product particle size.

Main Shaft: A forged alloy steel (40CrNiMoA) shaft with a tapered lower end (1:12 taper) that fits into the eccentric shaft sleeve. It transmits the rotational force from the eccentric sleeve to the moving cone, with a diameter ranging from 100 to 300 mm depending on the crusher model.

Eccentric Shaft Sleeve: A cast steel (ZG35CrMo) sleeve with an offset bore (eccentricity 8–25 mm) that drives the main shaft’s oscillating motion. It is mounted on spherical roller bearings and rotated by a bevel gear set (small and large bevel gears made of 20CrMnTi).

Motor and Pulley System: A variable-frequency motor (160–630 kW) connected to the input shaft via a V-belt and pulley, providing power to drive the eccentric sleeve. The motor speed is adjustable (500–1200 rpm) to adapt to different materials.

Multi-cylinder Hydraulic Unit: 6–12 hydraulic cylinders evenly distributed around the lower frame, responsible for adjusting the discharge port size (5–50 mm) and providing overload protection. Each cylinder has a working pressure of 16–25 MPa and is equipped with a pressure sensor for precise control.

Hydraulic Control Cabinet: Contains pumps, valves, and a PLC system to regulate cylinder pressure, enabling automatic adjustment of the discharge port and real-time monitoring of operating parameters.

Safety Relief Device: When uncrushable materials enter the crushing chamber, the hydraulic cylinders automatically retract to expand the discharge port, expelling the foreign matter, then reset to the original position to resume operation.

Thin Oil Lubrication System: An independent system with pumps, coolers, and filters that circulates lubricating oil (ISO VG 46) to bearings, gears, and the eccentric sleeve. It maintains oil temperature below 55°C and pressure at 0.2–0.4 MPa.

Dustproof Structure: A combination of labyrinth seals, oil seals, and air purge (0.3–0.5 MPa compressed air) to prevent dust and fines from entering the bearing and hydraulic systems.

Pattern Making: Full-scale wooden or metal patterns are created with shrinkage allowances (1.2–1.5%) and detailed features (ribs, flanges, oil passages).

Molding: Resin-bonded sand molds are used, with cores for internal cavities. The mold surface is coated with a zirconium-based refractory wash to improve surface finish.

Melting and Pouring:

ZG270-500: Melted in an induction furnace at 1520–1560°C, poured at 1480–1520°C under controlled pressure to avoid porosity.

ZG35CrMo: Melted at 1540–1580°C, with chromium and molybdenum added to achieve the required composition (Cr 0.8–1.2%, Mo 0.2–0.3%).

Heat Treatment: Normalization at 880–920°C (air-cooled) followed by tempering at 550–600°C to relieve internal stress and achieve hardness HB 180–220.

Pattern and Molding: Precision foam patterns with eccentric bore details are used for shell molding, ensuring dimensional accuracy of the offset bore (±0.05 mm).

Pouring and Heat Treatment: Molten steel is poured at 1500–1540°C. After casting, the sleeve undergoes quenching (850°C, oil-cooled) and tempering (580°C) to achieve hardness HB 220–260 and tensile strength ≥785 MPa.

Billet Heating: Steel billets are heated to 1150–1200°C in a gas furnace to ensure plasticity.

Open-Die Forging: The billet is upset and forged into a conical shape with a spherical base, with multiple passes to align grain flow along the stress direction.

Heat Treatment: Quenching (840°C, water-cooled) and tempering (560°C) to achieve tensile strength ≥900 MPa, yield strength ≥785 MPa, and hardness HRC 28–32.

Rough Machining: CNC milling shapes the flange surfaces and rib edges, with flatness tolerance (≤0.1 mm/m). Boring machines create bearing seats and hydraulic cylinder mounting holes with IT7 tolerance.

Precision Machining: Grinding of flange mating surfaces to Ra1.6 μm. Drilling and tapping of bolt holes (M30–M60) with thread class 6H, ensuring positional accuracy (±0.1 mm).

Turning: CNC lathes machine the outer diameter and eccentric bore, leaving 0.5–1 mm grinding allowance. The eccentricity is verified using a CMM.

Grinding: Outer diameter and bore are ground to IT6 tolerance, with surface roughness Ra0.8 μm. The gear mounting face is ground to perpendicularity (≤0.02 mm/100 mm).

Milling: CNC machining centers shape the conical surface and spherical base, with cone angle tolerance (±0.05°) and surface roughness Ra3.2 μm.

Liner Mounting Surface: Machined to flatness (≤0.1 mm/m) to ensure tight bonding with the wear-resistant liner via zinc alloy casting.

Material Testing:

Spectrometric analysis verifies chemical composition (e.g., ZG35CrMo: C 0.32–0.40%, Cr 0.8–1.2%).

Tensile and impact tests confirm mechanical properties (e.g., 42CrMo: impact energy ≥60 J/cm² at 20°C).

Dimensional Inspection:

CMM checks critical dimensions (e.g., eccentric sleeve eccentricity, frame bearing seat coaxiality).

Laser scanning verifies the moving cone’s conical profile and fixed cone cavity geometry.

Non-Destructive Testing (NDT):

Ultrasonic testing (UT) detects internal defects in cast frames and sleeves (defects >φ3 mm rejected).

Magnetic particle testing (MPT) inspects forged main shafts and moving cones for surface cracks.

Performance Testing:

Dynamic Balancing: Rotor and eccentric sleeve assemblies are balanced to G2.5 grade (vibration ≤2.5 mm/s).

Hydraulic System Test: Pressure cycling (0–25 MPa) for 1000 cycles with no leaks; response time of safety devices ≤0.5 seconds.

Crushing Test: 48-hour continuous run with granite (compressive strength 160 MPa) to verify capacity, particle size (cubicity ≥85%), and component wear.

Safety Validation:

Overload testing with 50 kg iron blocks confirms the hydraulic system triggers and resets correctly without damage.