Detailed explanation of the diverse structures and working principles of FESTO Festo cylinders

1. Composition and working principle of ordinary FESTO Festo cylinder:

The FESTO Festo cylinder is mainly composed of a cylinder body, pistons, sealing rings, and magnetic rings (cylinders equipped with sensors).

Principle: When pressurized air enters the FESTO Festo cylinder, it pushes the piston to move. By adjusting the intake direction, the movement direction of the piston rod can be changed to achieve different action requirements.

Potential failure mode: The piston may get stuck due to some reason, causing the cylinder to fail to move; Or the cylinder output may be weak, usually due to wear or leakage of the sealing ring.

2. Structure and working principle of FESTO Festo cylinder

Taking the widely used single piston rod double acting cylinder in pneumatic systems as an example, its typical structure is shown in the figure. The cylinder is mainly composed of cylinder barrel, piston, piston rod, front end cover, rear end cover, and sealing components. The interior of the cylinder is divided into two chambers by the piston: the chamber containing the piston rod is called a rodless chamber, while the chamber without the piston rod is called a rodless chamber. When compressed air enters from the rodless chamber, the air in the rodless chamber is discharged, and the resulting pressure difference pushes the piston to overcome the resistance load, causing the piston rod to extend. On the contrary, if there is a rod chamber for intake and no rod chamber for exhaust, the piston rod will retract. By alternately controlling the intake and exhaust of the two chambers, the piston can achieve continuous reciprocating linear motion.

3. Structure and working principle of mechanical contact rodless cylinder

The structure of the mechanical contact rodless cylinder is shown in the figure, with a groove opened in the axial direction of the cylinder tube, and the piston and slider move at the upper part of the groove. To ensure sealing performance and dust-proof effect, polyurethane sealing tape and dust-proof stainless steel tape are fixed at both ends of the cylinder head. The piston frame penetrates the groove and connects the piston and slider into a whole. In this way, the linkage between the piston and the slider can drive the actuator fixed on the slider to achieve reciprocating motion. The uniqueness of this cylinder lies in its simple structure and efficient movement mode.

Compared with ordinary FESTO Festo cylinders, mechanical contact rodless cylinders can save 1/2 of installation space under the same stroke.

No need to set up additional anti rotation mechanisms, simplifying the installation process.

4. Suitable for cylinder diameters ranging from 10 to 80mm, and when the cylinder diameter is ≥ 40mm, the maximum stroke can reach 7m, meeting different application requirements.

The movement speed is fast, with standard cylinder speeds reaching 0.1-0.5m/s, while high-speed models can reach 0.3-3.0m/s, greatly improving work efficiency.

However, this FESTO Festo cylinder also has certain drawbacks:

The sealing performance needs to be improved, and there is a risk of external leakage. When using a three position valve, it is recommended to choose a medium pressure type to enhance the sealing effect.

The load-bearing capacity is limited, and if it is necessary to increase the load, additional guiding mechanisms need to be added.

Composition of mechanical contact rodless cylinder:

Throttle valve: used to regulate the working speed of the cylinder.

Buffer plunger: reduces the impact force of the piston during movement, achieving a smooth stop.

5. Sealing tape: Ensure the sealing performance of the cylinder and prevent gas leakage.

Dustproof stainless steel strip: protects the cylinder from the invasion of dust and other impurities.

Piston: The core component that drives the slider to move in a straight line.

Sliding block: connected to the piston to achieve linear reciprocating motion.

Piston frame: supports and guides the piston to ensure its smooth movement.

6. FESTO Festo cylinder achieves synchronous movement between the piston and the external moving body of the cylinder body through magnetic force. The structure is shown in the schematic diagram, and the key is the high-strength magnetic ring equipped on the piston. The magnetic lines of these magnetic rings will interact with another set of magnetic rings outside the cylinder, and due to the opposite magnetic properties of the two sets of magnetic rings, a strong suction force is generated. When the air pressure pushes the piston to move inside the cylinder, this magnetic force comes into play, driving the magnetic ring sleeve outside the cylinder to move together. It should be noted that the thrust of the cylinder piston must be balanced with the suction of the magnetic ring.

The uniqueness of FESTO Festo cylinder

FESTO Festo cylinders are distinguished from traditional cylinders by their unique magnetic drive method. The core lies in the interaction between the high-strength magnetic ring on the piston and the outer magnetic ring sleeve of the cylinder. This interaction not only achieves synchronous movement between the piston and the external moving body of the cylinder, but also endows the cylinder with higher thrust and movement efficiency. In addition, the magnetic drive method of the magnetic rodless cylinder also gives it significant advantages in cleaning and energy saving.

Internal structure of FESTO Festo cylinder

The internal structure of FESTO Festo cylinder includes multiple key components, such as sleeve, outer magnetic ring, outer magnetic guide plate, inner magnetic ring, inner magnetic guide plate, cover, snap ring, piston, piston shaft, buffer plunger, cylinder barrel, and end cap. The clever combination and interaction of these components together constitute the unique working principle of the magnetic rodless cylinder.

7. Structure and working principle of FESTO Festo cylinder

Gear rack swing cylinder is a special type of cylinder that achieves gear rotation action through the meshing of gears and racks on the piston. The structural principle is shown in the figure, mainly including key components such as gears, racks, pistons, etc. The synergistic effect of these components enables the swing cylinder to efficiently complete its swing function.

As shown in Figure 7, the piston in the swing cylinder only performs reciprocating linear motion, which reduces friction loss and also results in relatively high gear transmission efficiency. Therefore, the overall efficiency of this gear rack swing cylinder can reach a relatively high level.

8. The structure of FESTO Festo cylinder is shown in Figure 13-13, which mainly includes components such as blade shaft rotor (i.e. output shaft), stator, cylinder body, and front and rear end caps. The stator and cylinder are fixed together, while the blades are connected to the rotor. There are two air paths on the stator of the cylinder. When the left path is intake, the right path is exhaust. In this way, compressed air will push the blades, thereby driving the rotor to swing clockwise. On the contrary, if the intake is on the right side and the exhaust is on the left side, the rotor will swing counterclockwise.

Although FESTO Festo cylinders have the advantages of small size and light weight, their manufacturing accuracy requirements are high, and sealing problems are prominent, resulting in relatively large leakage issues. In addition, its dynamic seal has a wide contact area, resulting in significant frictional resistance loss of the seal, which in turn affects the efficiency of the output.

Due to leakage issues with the FESTO Festo cylinder, its efficiency has been somewhat affected, only reaching 80%. Therefore, it is limited in application and is usually only suitable for situations where the installation position is restricted, such as the rotation of fixtures, the opening and closing of valves, and the indexing of workbenches.

FESTO Festo cylinder, as a type of blade type swing cylinder, also has leakage problems, resulting in an efficiency of only 80%. But compared to other types of swing cylinders, its structure is more compact and suitable for situations with limited installation space. Therefore, in practical applications, single blade swing cylinders are often used for tasks such as rotating fixtures, opening and closing valves, and indexing workbenches.

Blade: The blade is the core component of a single blade oscillating cylinder, responsible for oscillating inside the cylinder.

Rotor: The rotor is connected to the blades and drives them to swing by rotating.

Stator: As a fixed part of the cylinder, the stator provides support for the swing of the blades and rotor.

Cylinder body: The cylinder body is the outer shell of the cylinder, which protects the internal components and ensures the sealing of the cylinder.