A concrete mixer truck refers to a special concrete transportation equipment equipped with a concrete mixer on the chassis of a heavy-duty truck, also known as a vehicle-type concrete mixer. Concrete mixer trucks are specialized supporting equipment for transporting commercial concrete produced by concrete factories.

The characteristics of concrete mixer trucks are that they can maintain the uniform quality of concrete without bleeding, stratification, segregation or early setting when the transportation volume is large and the distance is long. They are suitable for road, airport, water conservancy projects and large-scale construction projects, and are indispensable equipment for the development of commercial concrete.
As a supporting transportation machine for concrete factories or mixing stations, concrete mixer trucks connect concrete factories, mixing stations and many construction sites. If used in conjunction with concrete pumps to carry out "relay" transportation at the construction site, concrete can be continuously delivered to the construction pouring point without the need for intermediate human turnover. Achieve high efficiency and full mechanization in concrete transportation. This not only significantly enhances labor productivity and construction quality, but also facilitates civilized construction on site. It particularly demonstrates its superiority in urban construction, especially in narrow construction sites.
A concrete mixer truck is composed of a heavy-duty truck chassis and a special device for concrete mixing and transportation.
The special equipment for concrete mixing and transportation mainly includes the power take-off device, hydraulic system, reducer, mixing drum, control mechanism, cleaning system, etc. The working principle is as follows: The power from the car chassis is extracted through the power take-off device and drives the variable pump of the hydraulic system, converting mechanical energy into hydraulic energy and transmitting it to the quantitative motor. The motor then drives the reducer, which in turn drives the mixing device to mix the concrete.
(1) Power take-off device
The function of the power take-off device is to extract the engine power by operating the power take-off switch, and drive the mixing drum through the hydraulic system. During the feeding and transportation process, the mixing drum rotates in the forward direction to facilitate feeding and concrete mixing. When discharging, it rotates in the reverse direction. After the work is completed, the power connection with the engine is cut off.
(II) Hydraulic System
The engine power taken out by the power take-off device is converted into hydraulic energy, and then output as mechanical energy through the motor to provide direct power for the rotation of the mixing drum.
(3) Reducer
The function of the reducer is to reduce the rotational speed output by the motor in the hydraulic system and then transmit it to the mixing drum.
(4) Stirring device
The mixing device mainly includes the mixing drum and the loading and unloading mechanisms.
1. Mixing drum
The mixing drum is the main specialized equipment of commercial concrete mixer trucks. Its structural shape directly affects the transportation and mixing quality of concrete, as well as the feeding and discharging speeds. The mixing drum is supported on three fulcrum points on different planes. The axis of the mixing drum is inclined at an Angle to the frame (horizontal line), usually 16° to 20°.
The working process of the mixing drum is as follows: When the mixing drum rotates clockwise, the drum wall and blades cause the mixed materials to continuously lift and fall down. At the same time, they move along the spiral direction of the spiral blades (towards the bottom of the drum). Meanwhile, the mixed materials at the bottom of the mixing drum, under the action of the end wall, roll upward, thus subjecting the mixed materials to a more intense stirring. When the mixing drum rotates counterclockwise, the spiral direction is upward. The spiral blades push the concrete mixture to move upward and discharge it from the material port. In order to facilitate feeding and uniform discharging, a guide pipe is installed inside the material opening. The mixture enters the mixing drum from the inner wall of the guide pipe and is discharged along the outer wall of the guide pipe.
2 Loading and unloading mechanisms
The loading and unloading mechanisms are installed at one end of the material opening of the mixing drum. The upper edge of the hopper wall of the commercial concrete mixer truck is hinged to the support with a pin shaft. The feeding port at the bottom of the feeding hopper is in close contact with the opening of the feeding guide pipe to prevent concrete from overflowing during feeding. The feeding hopper can also be flipped upwards around the hinge shaft to expose the material opening of the mixing drum, which is convenient for cleaning the mixing drum. On the supports on both sides of the material opening of the mixing drum, there are fixed discharge troughs, and beneath them, there is another movable discharge trough. The movable discharge trough can change its inclination Angle by adjusting the rod, so it can adapt to the requirements of different discharge positions.