Mobile Jaw Crusher

Detailed Introduction to Mobile Jaw Crushers

I. Equipment Overview

II. Composition and Structure

1. Crushing System

• Jaw Crusher Main Unit: The core working component, including a fixed jaw, moving jaw, jaw plates (made of high manganese steel ZGMn13 for wear resistance), an eccentric shaft (42CrMo alloy steel for power transmission), and a toggle plate (supporting the moving jaw and acting as an overload protection device). It is responsible for primary or secondary crushing of materials.

• Feeding Device: Usually equipped with a vibrating feeder to uniformly deliver raw materials into the crushing chamber, preventing blockages. Some models include a hopper for temporary material storage to ensure continuous feeding.

• Screening Device (Optional): Integrated vibrating screens in certain models enable classification of crushed materials. Qualified materials are directly discharged, while unqualified materials return to the crushing chamber for re-crushing, forming a closed-loop cycle.

2. Mobile Chassis System

• Tire-mounted chassis: Uses a heavy-duty truck chassis or special trailer chassis, equipped with hydraulic steering and braking systems. Suitable for road transportation with fast relocation speeds (up to 60 km/h).

• Track-mounted chassis: Adopts a hydraulically driven track 行走 mechanism with low ground pressure, suitable for complex terrains such as muddy areas and mountains, with a maximum climbing capacity of 30°.

• Chassis Structure: Available in tire-mounted and track-mounted types:

• Frame: Constructed from high-strength welded steel structures (Q355B steel) to bear the crusher main unit, motor, and other components, meeting impact resistance and load-bearing requirements.

• Hydraulic System: Controls chassis movement, main unit adjustments (e.g., crushing gap), and hopper lifting. Core components include hydraulic pumps, cylinders, and control valve groups (imported brands such as Bosch Rexroth and Parker).

3. Auxiliary System

• Power System: Equipped with a diesel engine (e.g., Cummins, Yuchai, power range 50–300 kW) or an electric motor (for use with external power supply) to provide power for the crusher main unit, feeder, and hydraulic system.

• Control System: A PLC control cabinet with a touchscreen enables equipment start/stop, parameter adjustment (e.g., feeding rate, crushing gap), and fault alarms (overload, excessive oil temperature). Some models support remote monitoring.

• Dust and Noise Reduction Devices: Optional pulse dust collectors (handling dust concentrations ≤30 mg/m³) and soundproof enclosures meet environmental requirements. A cooling system (water tank + fan) prevents overheating of the engine and hydraulic system.

III. Manufacturing Processes

1. Core Component Manufacturing

• Track Frame/Tire Frame: Welded from high-strength steel plates (Q355B), with post-welding aging treatment to eliminate stress. Critical welds undergo non-destructive testing (UT inspection).

• Hydraulic System: Hydraulic pipelines use cold-drawn seamless steel tubes (20# steel), assembled after pickling and phosphating. Pipe joints use flanged or ferrule connections to ensure sealing performance (pressure tested at ≥30 MPa for 30 minutes with no leakage).

• Moving Jaw and Fixed Jaw: Fabricated by cutting and welding Q235 or Q355 steel plates, with critical parts undergoing annealing to eliminate internal stress. Jaw plates are cast from ZGMn13 high manganese steel and water-toughened (heated to 1050°C, held, and rapidly water-cooled) to enhance toughness and wear resistance.

• Eccentric Shaft: Forged from 42CrMo round steel (forging ratio ≥3), rough-machined, then quenched and tempered (hardness 280–320 HB), followed by precision grinding (IT6 tolerance) to ensure journal accuracy.

• Jaw Crusher Main Unit:

• Mobile Chassis:

2. Assembly Process

• Modular Assembly: The crushing system, chassis system, and auxiliary system are pre-assembled separately, then integrated. Modules are fixed with locating pins and high-strength bolts (grade 8.8 or higher) to ensure coaxiality and perpendicularity (e.g., eccentricity ≤0.05 mm between the eccentric shaft and bearing housing).

• Hydraulic and Electrical Integration: Hydraulic pipelines are connected in a "main-first, auxiliary-second" sequence. Electrical wiring is protected by conduits, with IP65 waterproof connectors. A 2-hour no-load test is conducted after assembly to verify operational coordination.

IV. Quality Control Processes

1. Raw Material Control

• Critical steels (e.g., 42CrMo, Q355B) must provide material certificates, with spectral analysis and mechanical property testing (tensile strength, impact toughness). Castings (jaw plates) undergo non-destructive testing (MT inspection) to avoid internal cracks.

2. Processing Accuracy Control

• Crushing chamber dimensions: Tolerance ≤±1 mm, parallelism between moving and fixed jaws ≤0.1 mm/m. Eccentric shaft journal surface roughness: Ra ≤1.6 μm, bearing housing hole roundness error ≤0.01 mm.

3. Performance Testing

• No-load Test: 4-hour continuous operation to monitor bearing temperature (≤70°C), noise (≤95 dB), and vibration (≤0.15 mm/s).

• Load Test: 8-hour continuous crushing of standard hard rock (e.g., granite with 150 MPa compressive strength) to verify product size qualification rate (≥95%), production capacity (deviation ≤5%), and hydraulic system stability.

4. Safety and Environmental Testing

• Protective devices (e.g., guards, emergency stop buttons) must pass safety certification. Brake systems (tire-mounted) must achieve a braking distance ≤5 m (at 30 km/h). Emission standards (diesel models) must meet China Stage III or EU Stage III requirements.

V. Applications in Production Lines and Industries

1. Role in Production Lines

• As a mobile primary crusher, it performs on-site primary crushing of large materials (particle size ≤1000 mm) to medium sizes (50–300 mm), providing qualified feed for subsequent secondary and tertiary crushers.

• It can be combined with mobile cone crushers or impact crushers to form a "mobile crushing plant," enabling integrated "primary + secondary crushing + screening" operations. This forms a mobile production line, ideal for small mines and temporary projects.

2. Industry Applications

• Mining Industry: Used for crushing overburden and primary ore (e.g., iron ore, copper ore) in open-pit mines, reducing ore transportation costs—especially suitable for remote or topographically complex mines.

• Construction Waste Treatment: Crushes concrete blocks and bricks at demolition sites to produce recycled aggregates for road bases or recycled brick production, achieving "on-site utilization of local materials."

• Road and Infrastructure Engineering: Crushes roadbed aggregates (e.g., limestone, sandstone) in highway and railway construction, moving with the construction progress to meet on-site material demands.

• Water Conservancy Engineering: Crushes river pebbles and rocks for dam and reservoir construction, adapting to complex terrains around river channels.

• Metallurgical Industry: Crushes metallurgical slag (e.g., steel slag, blast furnace slag) to recover metal particles or produce recycled building materials, reducing solid waste accumulation.