The core technical objective of the container lifting system is to achieve precise lifting and positioning of the container to be filled at the filling station, ensuring the sealing fit and disconnection safety between the filling valve and the container opening. According to the power drive mode, it can be divided into three types of technical architectures:
Mechanical lifting mechanism
The fixed cylindrical CAM - offset direct-acting driven rod transmission mechanism is adopted. Through the rolling bearing, it moves along the trajectory of the CAM guide rail, driving the elastic sleeve assembly composed of the upper sliding cylinder, the lower sliding cylinder, the bottle support table and the compression spring to complete the lifting action. This mechanism has a short transmission chain and a compact structure. However, it has problems such as a high mechanical wear rate of the CAM pair and a short fatigue failure cycle of the compression spring. Moreover, it has strict requirements for the roundness tolerance and height tolerance of the container (usually controlled within ±0.5mm). It is only suitable for filling scenarios of low-viscosity liquid materials without gas (such as drinking water and condiments) The working pressure generally does not exceed 0.1MPa.
Pneumatic lifting mechanism
The lifting of the bottle support platform is achieved by using clean compressed air as the power source (the air source pressure needs to be stable at 0.4-0.6MPa), and controlling the reciprocating motion of the cylinder piston through a two-position five-way directional control valve. Its core technical advantage lies in its overload protection feature: when a bottle jamming fault occurs, the compressed air in the rodless cavity of the cylinder can be depressurized through the relief valve to prevent the container from being damaged under pressure. However, during the descent, due to the effect of gravity, the impact acceleration between the container and the bottle support platform can reach 1.2g, and the descent speed needs to be optimized through a buffer throttle valve. This mechanism is suitable for filling carbonated beverages (such as carbonated drinks and beer), and can effectively prevent liquid overflow caused by mechanical shock.
Air-mechanical hybrid lifting mechanism
Combining the flexibility of pneumatic drive with the precision of mechanical control, during the bottle lifting stage, compressed air (0.3-0.5MPa) is used to push the bottle support platform sleeve to slide along the hollow plunger. The lifting speed is precisely controlled by the motion pair of the CAM guide rail and the rolling bearing. During the bottle lowering stage, positioning is achieved by forced downward pressure through a CAM. Meanwhile, the compressed air in the plunger is recovered to the bottle support cylinder where the bottle is to be lifted through the gas path reversing valve, increasing the gas utilization rate by more than 30%. This mechanism has a positioning accuracy of ±0.2mm, excellent working stability, and is suitable for broad-spectrum filling requirements of both gas-containing and non-gas-containing, low-viscosity and medium-viscosity liquid materials. It is currently the mainstream configuration for medium and high-speed filling machines (400-1200 bottles per hour).
In what scenarios are different institutions respectively suitable for use?
Rotary filling machines generally use three types of lifting mechanisms, each with its own focus in different application scenarios: The mechanical lifting mechanism has a simple structure, but over long-term use, mechanical wear will be more obvious, and the spring is also prone to failure. It is more suitable for filling liquid materials without gas. The advantage of the pneumatic lifting mechanism is that it can prevent container damage even if the bottle gets stuck. However, the impact force generated when the container descends is greater, so it is often used in carbonated beverage filling machines. There is also a pneumon-mechanical hybrid lifting mechanism, which has particularly good working stability and a wide range of applications. It can basically be used in all types of filling scenarios.