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How does a rodless cylinder work?

Views: 304     Author: VPC Pneumatic     Publish Time: 2022-08-04      Origin: https://www.vpc-pneumatic.com/

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Rodless pneumatic cylinder has no piston rod but a piston device in the guide rail. Generally divided into magnetically coupled rodless cylinder (magnetic air cylinders) and mechanical rodless cylinder. The working of rodless air cylinder is that the piston is directly or indirectly connected to the external actuator and makes it follow the piston to achieve reciprocating motion. The most significant advantage is that it saves installation space and is suitable for cases requiring a small bore, long stroke cylinder.

smc rodless cylinder

CY1B Magnetically Coupled Rodless Cylinder

mechanical jointed rodless cylinder

OSP Mechanical Rodless Cylinder

Pneumatic Magnetically Coupled Rodless Cylinder

The working of magnetically coupled rodless cylinder is that the piston drives the cylinders outside objects to do synchronous movement by magnetic force. In the piston installed a set of high magnetic permanent magnetic ring, the magnetic line of force through the thin-walled cylinder and another set of magnetic ring set outside the role, due to the two sets of magnetic rings have opposite magnetism and strong suction force. When the air pressure inside the cylinder pushes the piston, then under the action of magnetic force, drive the cylinder outside the magnetic ring set together to move. 

The thrust of the cylinder piston must be compatible with the suction force of the inner and outer magnetic rings. When the air pressure is too high, or the load is too heavy, resulting in too much thrust of the piston, the magnetic rings cannot maintain the attraction between each other, which will separate the inner and outer magnetic rings and the problem of off-target will occur. The size of its load mass needs to find the characteristic curve of its mass and speed. Permanent magnets require high cleanliness and should be frequently removed and cleaned with gasoline to reduce failure.

Magnetically Coupled Rodless Cylinder Feature

 Small overall installation size, small axial space, about 44% saving axial space than standard cylinder.

 Magnetically coupled rodless cylinder has equal piston area at both ends of thrust and tension, so the thrust and tension are equal and can achieve intermediate positioning. When the piston speed is 250mm/s, the positioning accuracy can reach ±1.0mm.

 Standard cylinder piston rod surface quickly accumulates dust and rust. The rod seal ring may absorb dust impurities, resulting in leakage. In contrast, the external slider of the magnetic coupled rodless cylinder has no seal ring and no external leakage.

 Standard cylinder’s bore to stroke ratio is generally not greater than 1/15. Magnetically coupled rodless cylinder has long stroke specifications. The bore to stroke ratio can reach 1/100, the longest stroke up to 3m.

Magnetic rodless air cylinder CY1B, CY3B without guiding structure (basic type), CY1R direct mount type magnetic rodless cylinder (anti-rotation type), CY1S, CY1L (double rod type).

magnetically coupled rodless air cylinder
guided rodless cylinder

★ Magnetically Rodless Cylinder And Mechanically Rodless Cylinder Comparison

 Magnetically coupled type has a small profile, with mounting threads and nuts on both ends. And it can be mounted directly on the equipment.

 Magnetic rodless cylinder has a smaller load, suitable for loading small workpieces or manipulators.

 When the basic magnetically coupled type reciprocates, the slider may rotate, so must add a guide rod. Or choose the rodless cylinder with guide rod type.

 Compared with the mechanical type, there is no external leakage of the magnetic coupling type, maintenance-free after installation and use.

 Magnetic coupled rodless cylinder is suitable for slow speed (speed ≤700mm/s).

    Pneumatcic Mechanical Rodless Cylinder
    pneumatic rodless cylinder

    Mechanical Rodless Cylinder

    Mechanical type is divided into mechanically jointed rodless cylinder and cable cylinder. Mechanically jointed rodless cylinder in the cylinder tube axially open a slot, the piston, and slide in the upper slot to move.

    Cable Operated Rodless Cylinders

    The cable cylinder cable, one end and the piston connected, the other end through the end cover around the pulley and the mounting frame connected so that the two cables form a ring mechanism. When the compressed air is added to the piston side, the piston will be forced to move to the side of the cylinder, driving the cable along the pulley movement, through the cable connected to the installation frame will be the force output.

    Mechanical Jointed Rodless Cylinder

    To meet the need to prevent leakage and dustproof, a polyurethane sealing belt and dustproof stainless steel belt are fixed on the cylinder cover at both ends, and the piston frame passes through the groove to connect the piston and the slide into one. Piston and slider are connected, driving the actuator fixed on the slider to achieve reciprocating motion.

    Mechanical Air Rodless Cylinder
    VPC Mechanical Rodless Cylinder

    Mechanical Rodless Cylinder Feature

     Compared with standard air cylinder, the same stroke can be reduced by 1/2 installation position.

     Have larger load capacity and torque resistance.

     Applicable to cylinder bore 10 ~ 80mm, the maximum stroke in the cylinder bore ≥ 40mm up to 7m.

     High speed, standard type can reach 0.1~0.5m/s; high speed type can reach 0.3~3.0m/s.

     Mechanical Rodless Cylinder Disadvantages

     Poor sealing performance, there may be a slight external leakage. The use of 3 way solenoid valve must be used in the medium pressure type.

     If the load force is small, to increase the load capacity, the guide mechanism must be increased.

    Rodless cylinder can be basically divided into: OSP-P standard type, clean room type, explosion proof type, integrated VOE valve rodless air cylinder, dual drive type, rail type , heavy duty, active brake type, passive brake type, with position measuring system type, magnetic.

    Rodless Pneumatic Cylinder For Use

    ※ Rodless cylinder can not only fix the middle slider to use, must fix both ends before use.

    ※ Rodless Cylinder is preferably using floating connectors to avoid direct force, causing the cylinder tube to bend.

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