Air Cylinders

About Air Cylinders and Air Cylinder Manufacturers Including: Brass Cylinders, Cable Cylinders, Compact Cylinders, Compressed Air Cylinders, Double Acting Cylinders, Miniature Air Cylinders, Pneumatic Cylinders, Rodless Cylinders, Rotary Cylinders, Single Acting Cylinders, Small Air Cylinders & Stainless Steel Cylinders. 

Air cylinders are the final component in a pneumatic or compressed air control or power system. They are used in the food processing and packaging, metal working, automotive, mining, textile, and forest industries. Also referred to as compressed air cylinders or pneumatic cylinders, air cylinders are devices that convert compressed air power into mechanical energy. This mechanical energy produces linear or rotary motion. In this way, the air cylinder functions as the actuator in the pneumatic system, so it is also known as a pneumatic linear actuator. The air cylinder consists of a steel or stainless steel piston, a piston rod, a cylinder barrel and end covers. As compressed air moves into a cylinder, it pushes the piston along the length of the cylinder. Compressed air or a spring, located at the rod end of the cylinder, pushes the piston back. Valves control the flow of compressed air to the cylinder. There are two basic types of air cylinders-double acting cylinders, which are able to perform an operating motion in two directions and single acting cylinders, which are able to perform in one. Other types include rotary cylinders, cable cylinders and rodless cylinders. They are housed in different styles and named accordingly. These include stainless steel cylinders, brass cylinders, compact cylinders, miniature air cylinders and small air cylinders.

Air cylinder manufacturers produce two basic types of air cylinders: single acting and double acting. The single acting cylinder is able to perform an operating motion in only one direction. It has air pressure on one side of a piston flange, supplying force and motion, and a spring supplying the return force after pressure release. Single acting cylinders require approximately half the amount of air used by a double acting cylinder for a single operating cycle. A double acting pneumatic cylinder has powered motion in two directions, with pressure on both sides. When a cylinder is pushed out in one direction, compressed air moves it back in the other direction. Air lines running into both ends of the cylinder supply the compressed air. The flow of compressed air is controlled with valves for both single and double acting cylinders. Cable cylinders have elongated housing, 2 rollers and a cable that extends from one end to the other. Rotary cylinders differ from typical air cylinders because they provide the ability to move machine tooling in a revolving motion, instead of linear. Rodless cylinders are made of long, aluminum barrels formed with a vertical slot which allows the piston to connect to the mounting carriage. They are actuators that use a mechanical or magnetic coupling to convey force, usually to a body that moves along the length of the cylinder, but doesn't extend beyond it. Cable cylinders are rodless, but don't use the same type of sealing method and have a cable attaching either sides of the piston instead of a rod.

Every pneumatic air cylinder has specific components, although different versions vary somewhat. A typical cylinder consists of a rod, which is a linear actuator kept inside the cylinder, a port, which is a hole in the cylinder that the compressed air (media) is conveyed to attain linear movement, piston seals, anodized heads, wrench flats and mounting cylinders for installation. Housings for air cylinders come in a wide variety. Those made out of brass and stainless steel are suitable for harsh environments, where they will be thoroughly and hygienically cleaned, or exposed to corrosive forces. Miniature and small air cylinders are single-acting and disposable. Their springs are housed inside enlarged piston rods and they operate in reverse motion. Compact cylinders' overall dimensions are much smaller than other cushioned cylinders. Therefore, they are used where space is very limited.  

Manufacturers of air cylinders produce many different cylinder designs for a variety of applications in different industries. Choosing an air cylinder for a pneumatic system can be a difficult task. Air cylinder manufacturers can customize units with a special stroke, a custom mounting style or unusual seal material. Although custom air cylinders have the advantage of exactly suiting the application, it is recommended to look for an off-the-shelf solution first, as standard air cylinders cost less and are available for quick delivery. With sizing cylinders, focus on the load, velocity and air pressure. The cylinder should be sized to move the greatest load at the lowest acceptable velocity with the minimum available pressure. Determine the stroke length, the spring force (for a single-acting cylinder) and the overall dimensions of the cylinder. The mounting style-the options for which include nose, block, universal, pivot and trunnion-is determined by the size, force and function of the cylinder. Optional components that help to improve cylinder performance or prevent problems include cushions, bumpers, stop tubes, dual pistons, flow controls, position-sensing switches and position feedback sensors. Environmental factors have a huge impact on cylinder operation, so choose seals, beatings, lubricants, materials and finishes that will help counteract any negative effects.

Air Cylinders Images provided by Humphrey Products Corporation

Types of Air Cylinders

• Adjustable stroke cylinders have adjustable stops at one or both ends to restrict the amount of piston travel.
  
• Clean profile cylinders are flat barrels with round edges and T-slots for sensors along the entire length of the barrel on three sides. Clean profile cylinders are used in applications that require ease of cleaning and good hygiene, as the clean, square line design prevents the collection of dust and dirt.
  
• Compact cylinders, also called "short stroke cylinders," are cylinders whose overall dimensions at zero stroke are minute compared to the typical cushioned cylinders. These low-profile cylinders are used in applications in which there is not enough space for a standard length cylinder, as they can lock or move short distances, even in limited spaces.
  
• Compressed air cylinders convert power from compressed air into mechanical power.
  
• Double-acting air cylinders have air lines that provide pressure to both ends of the cylinder, supplying motion in two directions. The flow of compressed air is controlled by valves.
  
• Double rod cylinders have one piston, and the piston rod extends from both ends of the cylinder.
  
• Miniature air cylindersMiniature air cylinders, also called "microcylinders," are small, rectangular, single-acting air cylinders in which the springs are housed inside enlarged piston rods. Miniature air cylinders operate in reverse motion, are easy to install, offer a range of interchangeable mounting brackets, which attach to the cylinder ends to provide versatility and adaptability, and can be powered by plant air.
  
• Multiple bore cylinders have two or more boxes and pistons combined or stacked in the same cylinder.
  
• Multiple-position cylinders are double-acting cylinders that consist of two cylinders with the same diameter. Multiple-position cylinders provide three or more end positions, as opposed to the normal two provided by other double-acting cylinders.
  
• Non-rotating cylinders are cylinders in which the piston rod, ram or plunger and the relative rotation of the cylinder housing and piston are set.
  
• Pancake cylinders have shorter lengths and larger diameters than other cylinders.
• Pneumatic cylinders are comprised of a piston, a lower and upper port and an expansion chamber.
  
• Reverse single acting air cylinders are similar to single acting air cylinders, but the port is located on the opposite end in order to provide power on the retraction, or "pull" stroke.
  
• Single-acting air cylinders have air pressure that supplies motion and force from one side of the piston flange and a spring that provides the return force after pressure release. Single-acting air cylinders utilize about half the amount of compressed air, which is controlled by valves, required by double-acting air cylinders for a single operating motion.
  
• Smooth body cylinders are cylinders in which the cylinder body encases the piston.
  
• Rectangular cylinders are encased in a rectangular, box-shaped frame.
  
• Rodless cylinders have an extruded anodized aluminum barrel that is formed with a longitudinal slot, permitting the connection of the piston to the mounting carriage. A hardened stainless steel band pneumatically seals the cylinder, while a second stainless steel band on the exterior closes the slot and prevents contamination to the interior of the cylinder; a system of slide rails divides the two bands in the pressure-free zone between the two piston seals, which allows movement of the mounting carriage.
  
• Single rod cylinders have only one piston, and the piston rod extends from only one end.
  
• Stainless steel cylinders are suitable for harsh environments in which they will be rigorously cleaned for hygienic reasons or exposed to corrosive forces. Stainless steel cylinders are often referred to as "throwaway," as they are irreparable, and therefore, the cheapest of all cylinders.
  
• Tandem cylinders consist of two or more cylinders with linked piston assemblies.
  
• Tie-rod cylinders are held together by exterior tie rods and are usually in a rectangular bolt pattern.
  
• Twin rod cylinders consist of a series of twin-cylinder slide units and feature side-by-side twin cylinders in one body and two piston rods connected with a mounting plate. This design guarantees precise guiding compared to a typical cylinder and applies double the force of a cylinder of the same height.