The hydraulic cylinder (hereinafter referred to as the oil cylinder) is used in hydraulic system of components, in hydraulic system plays the role of the executor, other components such as pump, valve, oil filters accessories, etc are for hydraulic cylinder supporting service, oil cylinder of the hydraulic control system as the ultimate actuators, in mechanical equipment plays a very important role. So how to the correct choice of hydraulic cylinder is to become the enterprise special issue of concern. The following is a brief explanation of the problems.

The hydraulic cylinder mainly by the cylinder, piston, piston and cylinder head, cylinder tail, seal, accessories and other components, including the piston and cylinder, piston, called 3 big oil cylinder. Influence factors of the quality in oil cylinder are three: design experience, and processing quality, use maintenance.

(a) design experience

A rich experience in the design of hydraulic engineers oil cylinder, must know the following parameters:

A. cylinder size, stem diameter, travel

B. work pressure or oil cylinder load

C. work environment temperature

D. work medium

E. speed

F. other parameters, such as connecting forms and installation size

Cylinder size, stem diameter, trip by national standards as far as possible or other standards, avoid to choose non-standard sizes, or increase processing the difficulty and the manufacturing cost. According to the length of the trip to the length of the oil cylinder orientation. According to the working pressure or load to checking the cylinder, the piston rod, the strength of the screw, etc. At the same time work pressure, temperature, medium speed, is the key to have to choose the seals. The different types of seal susceptive pressure, temperature, medium, speed is not the same, water-glycol medium (HFC) can't use polyurethane sealing, can only use rubber seal; Oil cylinder fast operation must be used when sliping type sealing, sealing, case, something like this to circle, GD1000K, TDI, running at a slower speed can be used when Yx type, U, V type combined sealing, etc.; Under the environment of high temperature and high pressure fluoro rubber seal; Fast operation must be considered when set, the buffer valve with buffer. In addition, parts of the material selection must also be prudent. In short, the oil cylinder design is the first step of product quality, if the design is incorrect, processing quality again good also cannot meet the requirements. At present some professional manufacturer also manufacturing oil cylinder, because of the lack of design experience, so product is often a problem.

(2) the machining accuracy

Hydraulic cylinder of machining accuracy depends on the level of equipment, production technology and detection means.

Cylinder processing method commonly used two kinds, one kind is thick boring-fine boring-rolling, general use 45 # seamless steel tube, this kind of method processing quality is good, but the cost is high. Another method is to use # 20 cold drawn seamless steel tubes, and honing, cost is the end. The piston rod before processing must be conditioning straightening, coating thickness of piston rod generally not less than 0.03 mm. The piston processing must be in strict accordance with the sealing parts manual given groove size tolerance zone requirements. Now some manufacturer in order to reduce the cost, the piston rod not conditioning, stem coating is not enough, cylinder smoothness of less than, guide the copper don't set, and instead nodular cast iron, although less costly, but the quality of hydraulic cylinder is not required.

(3) use maintenance

The hydraulic cylinder if fully meet the requirements of customers, in addition to the above two factors outside, still have a point is to correct use and regular maintenance. Oil cylinder to put before use gas, buffer regulator transferred to reasonable position, and cleanness oil to regular inspection, the oil cylinder the dust on the regular cleaning, another note waterproof, fire prevention.

Nearly 20 years in China hydraulic industry development is rapid, hydraulic cylinder can completely replace the imported, according to our experience, the oil cylinder of processing level of domestic manufacturer completely pass, the key lies in seal, domestic seal can not completely replace the imported, so we suggest that important use cases, sealers had better choose the entrance.