auxiliary components can be required to complete a task. The motive force is supplied by an external pump powered by hand, electricity, air, or gasoline driven. A simple connection between port and pump or a circuit is attached to the cylinder in order to convey fluid. Normal fluid power accessories like control valves, hoses, gauges and fittings complete the hydraulic circuit. In some instances an accumulated fluid volume is necessary; this is provided by a fluid storage tank, often referred to as a reservoir. See the diagram entitled Typical Circuit for a Hydraulic Cylinder Jack to get a diagrammatic view of some of these components.
How do I pick the right cylinder to fit my job?
Choosing the right cylinder for your application boils down to answering a list of simple questions:
- Will your job require a pushing or lifting action or a pulling action, or possible both? Single acting cylinders extend the plunger when pressurized; double acting cylinders extend and also retract the plunger when pressurized thus providing force in two directions.
- How much clearance exists between the item you wish to manipulate, i.e. the load, and surrounding stationary structures such as floors or walls? If space is abundant then a standard profile cylinder will be satisfactory. If space is limited then a low profile, ultra-low profile, or even a flat (pancake) profile cylinder may be in order.
- What is the amount or distance of movement that will be necessary? This will dictate the required stroke of the cylinder.
- After lifting, will the manipulated item (load) need to be suspended for an extended period? If the ancillary hydraulic accessories will not be permanently available to the job, then a cylinder with a locking collar (nut) should be selected so that the load can be indefinitely supported mechanically.
- Will the cylinder be relatively stationary during the course of the job, or will its frequent relocation and positioning be necessary? If portability is important, then consideration should be given to lightweight model cylinders fabricated of aluminum.
- Is the insertion of objects through the center of the cylinder necessary as in tensioning or extracting operations? A center hole (hollow) cylinder should be chosen.
- Will the job require repeated cycling of the plunger as in a production application? The standard cylinder is for light duty, less than 2,500 life time cycles. Heavy duty industrial grade duty cycle cylinders are available from several manufacturers.
- And last, but certainly not least, how much plunger force is needed? How heavy is the object you wish to lift, jack, position, pull, or otherwise manipulate. Select a suitable cylinder capacity keeping in mind that an over-capacity margin should be applied.