Hydraulic cylinders are more than just a small cog in a big machine. They are often considered motors or actuators as they are capable of producing work. They are commonly called mechanical actuators or linear motors (not hydraulic motors which carry out rotary movement instead of linear movement). Depending on the intended use, the cylinders can be classed into different groups, the most popular being the double-acting cylinder, marine cylinder, rotary hydraulic cylinder, vibratory cylinder and more.

1. Piston Rod
Precision honed piston rod is made of high-strength carbon steel or alloy steel, which has been heat treated for improved rigidity. Chromed surface gives 0.2μm roughness all while protecting the thin oil film that lubricates the rod. A well-lubricated piston rod in turn improves the service life of rod seals.

For piston rods with a required rod to stroke ratio well above 20, we can put them through quenching and tempering processes to obtain HB217-255 hardness if Grade 45 steel is used or HB230-280 hardness with 42CrMo.

A layer of nickel will be deposited onto the rod surface before chrome plating applies. Double-layer plating improves corrosion resistance. A safety factor of 4:1 is guaranteed around the smallest cross section along the piston rod and piston assembly when subjected to rated load.

Cylinder Gland
The cylinder gland guides the piston rod to move up and down. High-strength ductile iron construction resists wear and tear. Available in a proper length, the cylinder gland takes more side load, thereby reducing the stress exerted on the shaft, which in turn improves the service life of the hydraulic cylinder and sealing elements.

Cylinder
Cylinder wall thickness is calculated at 1.5 times the rated pressure of the cylinder. Made using high-strength alloy steel, the hydraulic cylinder features a smooth internal surface well-honed to 0.4μm surface roughness all while achieving rated cylindricity. The resulting cylinder is straight, smooth, perfectly round and has not taper, causing minimized friction to o-rings thereby improving their life.

Piston, Piston Seal
Featuring one-piece steel construction, the piston works coaxially with the piston rod. Threaded connection is tight, locking together both the piton and rod, which is unlikely to shake loose at high speed or under heavy load. 5-piece piston seal assembly provides optimal sealing performance in both directions of travel, and has a rubber o-ring included in the assembly. The seals, when under huge pressure, may flow (or technically speaking, extrude) into the clearance between the piston and cylinder. That is why we add back—up rings to prevent rubber seals from moving into that open passage causing tear or nibbling. Step-cut wear bands eliminate metal to metal contact, protecting rubber seals from contamination or damage.

Buffering Feature
The buffering feature is one of our original inventions for which we’ve already filed a patent application. This little job can adjust stroke speed and time according to the varying load. The working principle of our buffering device is the change of flow area inside the cylinder using a buffering chamber that maintains a certain pressure or varies the pressure progressively to achieve the goal of lessening the direct impact on the cylinder head and bottom. In this way, a smooth cylinder operation is assured. All hydraulic parts including valves, pipes, meters and fittings will function normally for an extended life.

Welding Capability
Using robotic arms for automated friction welding ensures consistent welding results otherwise impossible with manual welding. Improved welding quality and efficiency is further guaranteed thanks to the use of ultrasonic flaw detector.

Sealing Elements
We decide the kind of sealing elements for use according to the specific working conditions where they are used, including temperature, oil type, and desired sealing style.