Designing a jaw stone crushing machine involves several key steps, from understanding the basic principles to selecting materials and components. Below is a structured approach to help you design an efficient and durable jaw crusher:
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1. Understand the Working Principle
A jaw crusher operates by compressing rock/stone between two jaws:
– Fixed Jaw – Stationary surface.
– Movable Jaw – Moves in an elliptical motion to crush material against the fixed jaw.
The crushed material exits through the discharge opening at the bottom.
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2. Define Requirements & Specifications
– Input Size (Feed Opening) – Maximum size of stones it can accept.
– Output Size (Discharge Setting) – Desired crushed stone size.
– Capacity (TPH – Tons Per Hour) – Required throughput.
– Power Source – Electric motor, diesel engine, or hydraulic drive.
– Material Hardness – Determines wear resistance needed.
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3. Key Components to Design
# (A) Jaw Plates (Crushing Surfaces)
– Made of high manganese steel (Mn14%, Mn18%, Mn22%) for durability.
– Replaceable liners to extend lifespan.
– Corrugated/toothed surfaces for better grip on stones.
# (B) Frame & Structure
– Heavy-duty steel construction (e.g., carbon steel or alloy steel).
– Reinforced ribs for strength against high impact forces.
# (C) Eccentric Shaft & Bearings
– The shaft drives the movable jaw via a flywheel and toggle mechanism.
– Use high-quality bearings (spherical roller bearings) for smooth operation.
# (D) Toggle Plate & Adjustment System
– Acts as a safety mechanism to prevent damage from uncrushable material.
– Allows adjustment of the discharge opening (CSS – Closed Side Setting).
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# (E) Flywheel & Pulley
– Stores energy to ensure consistent crushing force.
– Balances load on the motor.
# (F) Lubrication System
– Grease or oil lubrication for bearings and moving parts.
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4. Design Calculations
# (A) Crushing Force Calculation
\[ F = \sigma \times A \]
Where:
\( F \) = Crushing force
\( \sigma \) = Compressive strength of stone (~150–350 MPa for granite)
\( A \) = Area of crushing surface
# (B) Motor Power Estimation
\[ P = \frac{Q \times Wi}{\eta}