Concrete mixer machine with pump is a kind of engineering machinery that integrates concrete mixing and pumping functions, and is widely used in construction. The working principle of concrete mixer machine with pump mainly relies on the synergy of hydraulic system, pumping system and feeding system, and realizes continuous delivery of concrete through mechanical structure and hydraulic power.

 
1. Core system composition and working principle
(1). Mixing system: mixing uniform concrete
- Structure: mainly composed of mixing drum (or mixing tank), mixing blades, and drive motor (or hydraulic motor).
- Principle:
After cement, sand, gravel, water and other raw materials are put into the mixing drum according to the proportion, the mixing blades rotate at high speed (usually 10~30 rpm) under power drive, and the raw materials are mixed into uniform concrete through shearing, extrusion and flipping.
During the mixing process, the angle and layout design of the blades ensure that the concrete does not segregate, maintain good workability (fluidity, cohesion), and provide conditions for subsequent pumping.
Some mixing pumps have "forward and reverse" functions: forward mixing, reverse can discharge residual materials in the mixing drum or adjust the state of concrete.
 
(2). Pumping system: push concrete to the pouring point
- Structure: It is composed of the main oil cylinder, concrete cylinder, distribution valve, delivery pipeline, piston, etc., and the core is "hydraulic piston pumping".
- Principle (taking double-cylinder piston pumping as an example):
Suction stroke:
The piston rod of the main oil cylinder A retracts, driving the piston in the concrete cylinder A to move backward, forming a negative pressure in the cylinder, and the distribution valve (such as S valve) connects the concrete cylinder A and the hopper. The concrete is sucked into the concrete cylinder A under the action of atmospheric pressure and deadweight. At this time, the piston rod of the main oil cylinder B extends, and the piston in the concrete cylinder B moves forward, pushing the concrete in the cylinder to the distribution valve and discharging it through the delivery pipeline.
Discharge stroke:
The piston rod of the main oil cylinder A extends, pushing the concrete in the concrete cylinder A to move toward the distribution valve; at the same time, the distribution valve switches direction, connects the concrete cylinder B and the hopper, the piston rod of the main oil cylinder B retracts, and the concrete cylinder B starts to absorb the material. This cycle realizes the continuous pumping of concrete.
Key role of distribution valve:
Distribution valve (such as S valve, gate valve) ensures one-way flow of concrete and avoids backflow by periodically switching the connection status between concrete cylinder, hopper and conveying pipeline. S valve is widely used in large pump trucks due to its good sealing and wear resistance.

(3). Power and hydraulic system: provide energy transmission
- Power source: usually diesel engine (field operation) or electric motor (fixed site), drive hydraulic pump through gearbox or coupling.
- Hydraulic system:
Hydraulic pump converts mechanical energy into hydraulic energy (high-pressure oil) and transmits it to each actuator (main cylinder, mixing motor, distribution valve cylinder, etc.) through oil pipe. The hydraulic valve group controls the direction, pressure and flow of oil flow to ensure the coordinated action of mixing system and pumping system. For example:
The reciprocating motion of the main cylinder is driven by hydraulic oil, and the pumping pressure can be adjusted by the hydraulic system (usually the pumping pressure is 8~16MPa, and the high-pressure pump can reach more than 20MPa).
The accumulator in the hydraulic system can buffer pressure fluctuations and ensure smooth pumping.

(4). Conveying and material distribution system: precise positioning and pouring
- Conveying pipeline: It is composed of high-strength steel pipes, elbows, and connectors, arranged along the construction route. The inner diameter of the pipeline is usually 125~150mm to ensure smooth passage of concrete.
- Material distribution device:
The vehicle-mounted mixing pump (pump truck) is equipped with a foldable material distribution arm (multi-section hydraulic telescopic or folding), and the end is connected to a hose. The operator controls the rotation and pitch of the material distribution arm through hydraulic pressure to transport the concrete to the pouring position, without manual handling, which improves efficiency.

(5). Control system: coordinate the operation of various components
- Electrical and hydraulic control: Through PLC (programmable logic controller) or relay circuit, combined with pressure sensors, travel switches and other components, automatic control is achieved:
Set the mixing speed, pumping frequency, and monitor system pressure, oil temperature and other parameters.
It has fault alarm function (such as pipeline blockage, hydraulic oil overheating), and can automatically adjust or shut down for protection.
- Human-computer interaction: The operator controls the mixing, pumping, material distribution and other actions through the control panel or remote control, and flexibly adapts to construction needs.

 
2. Workflow of concrete mixer with pump:
- Raw material input and mixing: Raw materials are poured into the mixing drum, and the mixing system mixes them into uniform concrete.
- Pumping preparation: The hydraulic system is started, the distribution valve is reset, and the main cylinder starts to reciprocate.
- Circulation pumping: The concrete cylinder alternately sucks and discharges materials, the distribution valve switches direction, and the concrete is continuously output through the pipeline.
- Material casting: The direction is adjusted by the material arm to transport the concrete to the designated location.
- Stop and clean: After the operation is completed, use high-pressure water or a cleaning ball to clean the mixing drum and pipeline to prevent the concrete from solidifying.
 
3. Key technical points of concrete mixer machine with pump:
- Concrete workability control: The mixing system needs to ensure that the concrete slump is moderate (usually 120~200mm) to avoid high pumping resistance and pipeline blockage due to excessive dryness, or segregation due to excessive thinness.
- Matching pumping pressure and flow: Adjust the pumping pressure according to the pouring height and distance. For example, high-rise buildings require higher pressure (above 20MPa), and the pumping flow (50~120m³/h) is adjusted through the hydraulic system.
- Wear-resistant design: The distribution valve, concrete cylinder, blades and other parts in contact with concrete are made of wear-resistant materials (such as high-chromium cast iron) to extend the service life.
 
The concrete mixer machine with pump integrates the concrete production and transportation links through the integrated design of "mixing-pumping-distribution", greatly improving the construction efficiency. It is an indispensable equipment in modern construction projects.