ISUZU Concrete mixer trucks, commonly known as "cement mixer trucks", are essential vehicles for efficient transportation and mixing of concrete in construction. They consist of a special chassis with integrated rotating drum and hydraulic mixing system. This article will explore the key components and working principles of these vehicles.
A. Main components of concrete mixer trucks
1.1 Chassis and power system
- Most Chinese-made mixer trucks use a standard Class II commercial truck chassis.
- Power comes from the vehicle engine, which drives the hydraulic pump through the power take-off (PTO) system.
1.2 Power take-off (PTO) device
- Transmits engine power to the hydraulic system.
- Engage/disengage mixing operation through the control switch.
- Ensure that the drum rotates forward for mixing and reverses for unloading.
1.3 Hydraulic system
- Converts mechanical energy from the PTO into hydraulic energy.
- The variable pump drives the hydraulic motor, which in turn drives the mixing drum to rotate.
1.4 Speed Reducer (Gearbox)
- Reduces high-speed motor output to optimum drum speed (typically 2-6 RPM).
- Ensures smooth, controlled mixing.
1.5 Mixer Drum
- Made of high-strength, wear-resistant steel.
- Contains spiral blades inside for:
- Mixing concrete by lifting and tumbling the material.
- Efficient unloading when reversing.
- Drum capacity typically ranges from 3 m³ to 12 m³, depending on truck size.
1.6 Operating Mechanism
- Controls:
- Direction of rotation (forward for mixing, reverse for unloading).
- Speed (adjustable for different mixing stages).
1.7 Cleaning System
- Flushes residual concrete to prevent hardening.
- Cools the hydraulic system during operation.
- Some models include a drying function for special materials.
B. Working Principle
2.1 Power Transmission
The truck engine drives the Power Take-Off (PTO), which in turn activates the hydraulic pump.
The hydraulic pump delivers high-pressure oil to the hydraulic motor, which converts hydraulic energy into mechanical rotation.
2.2 Mixing process
The mixing drum rotates clockwise (forward) during transport, keeping the concrete moving and preventing settling.
The spiral blades lift and tumble the mix to keep it at a uniform consistency.
2.3 Discharging process
The mixing drum rotates counterclockwise (reverse), pushing the concrete outward through the blades.
Control the discharge speed to ensure accurate positioning.
2.4 Cleaning and maintenance
After discharging, the mixing drum needs to be flushed to prevent concrete buildup.
Cool the hydraulic system to maintain efficiency.
2.5 Key considerations for optimal performance
- Blade integrity: Worn or damaged blades can cause uneven mixing and material segregation.
- Hydraulic system maintenance: Regular inspections prevent leaks and ensure smooth rotation of the mixing drum.
- Load capacity: Overloading can cause inefficient mixing and mechanical stress.
- Speed control: Proper adjustment prevents concrete separation or spillage.
Concrete mixer trucks combine mechanical, hydraulic and structural engineering to efficiently deliver ready-mixed concrete. Understanding their components and working principles ensures their proper functioning, maintenance and longevity. Whether for small (3-6 cubic meters) or large (9-12 cubic meters) loads, these machines are indispensable in modern construction.
