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Telescopic Cylinder used for dump truck

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Order phone:+86-510-80628100


WHDJ multistage telescopic cylinder is mainly installed at limited space, such as dump trucks, garbage compression vehicle, hydraulic stage, all kinds of lifting platform and so on.

WHDJ cylinder has three installations :bottom joint bearing and ear ring type ;cylinder body with flange type; cylinder body with cardinal axis type . WHDJ there are eight kinds of piston diameter, it can be composed of eight kinds of two stage cylinder, seven kinds of three stage cylinder, six kinds of four stage cylinder and five kinds of five stage cylinder. Under the premise of stability, we can provide more than 20 meters multistage telescopic cylinders to our customers. Rated pressure WHDJ multistage cylinder is 16Mpa; if short stroke WHDJ per level stroke is less than 500mm, the rated pressure is 21Mpa.

1.WHDJ selection

1.1 Working pressure: WHDJ rated pressure 16Mpa, your system pressure should be set in this range. WHDJ factory test pressure 24~25Mpa. If stroke per class WHDJ≤ 500mm, the rated pressure can reach 21Mpa, but in must be noted before the order.
1.2 To determine the diameter of WHDJ in the selection of multistage cylinder. If you need WHDJ full stroke output at constant thrust, the pushing force that top piston (diameter minimum level) generate with hydraulic system must be higher than required constant thrust. For example you need constant thrust is 30KN, the pressure on your system is 12 MPa. When you select the heads of the diameter of the plunger diameter 56.4, at this time you should be selection of specifications similar diameter 60 heads of the cylinder. If your system pressure is 16Mpa, from page three parameters in the table you can directly select the diameter of cylinder head 45. If you need the thrust is variable, you should draw variable force and stroke curve graph and stroke WHDJ thrust curve diagram, make choice of the best bore. Since the WHDJ is a single acting piston cylinder, the return must rely on gravity loads or other forms of external forces. WHDJ minimum start pressure is less than 0.3Mpa, which can calculate each plunger cylinder minimum return force.
1.3 Determine stage quantity of WHDJ: after determining the diameter of WHDJ. You could calculate stage quantity according to total cylinder stroke and allowable close size . For example: you choose R type installation that you need to travel 5000mm, heads of the cylinder plunger diameter 45mm, two ear center distance maximum allows for 1800.Firstly you could suppose that this cylinder has three stages, then check the installation dimension tables L3=303+S/3,L17=105L3+L17=303+5220/3+105≈2074>1800, three cylinder does not meet requirements, thus to choose four stages cylinder, look-up table L3=315+5000/4, L17=130, L3+L17=1695<1800, four stage cylinder could meet your requirements.
1.4 Determine X size on the F type and Z type: Z type cylinder body with cardinal axis and F type cylinder body with flange position can be determined, but the X size shall not exceed sixth pages in the installation size table, that is, cardinal shaft and flange can not exceed the ends of the cylinder.
1.5 To determine the location of F type WHDJ stopper: flange (diameter 5e8) is set to the precise positioning of the axis of the cylinder. Flange on both sides of the two positioning stop, simply it is enough to choose one side, the majority of cases often use L16 (D), in the absence of accurate positioning of the cylinder axis, it can not choose to locate the stop.
1.6 Running speed and sequence of WHDJ
Since WHDJ is composed of more than one piston, the speed of each cylinder is different when the system flow is constant. In the lifting load process, At the normal situation the first large plunger run out at first, and the speed is slow. When large piston stroke come to the end , the next big plunger then extend, and the speed will change quickly; the smallest plunger finally run out, but its running speed is the fastest. When it returns under the action of external force, minimum plunger retracts at first,it speed is fast, and then successively retract; maximum plunger finally retract, speed is the slowest. If speed and sequence is abnormal, the possible reasons is too big or too small friction inside the cylinder .Usually ,we calculate all of the running time according to All of the stroke , it isn’t calculated according to one stage stroke.
1.7 WHDJ working medium: Standard WHDJ using clean hydraulic oil (NAS7-9) as a working medium. If it use water glycol, emulsion and other water medium, It should be identified with W wen it is ordered . Other phosphate, acid and alkali media etc should be marked with words.All off factory tests would choose hydraulic oil, and a small quantity of hydraulic oil would be kept inside cylinder to prevent the rust and corrosion during transportation and storing . The cylinder should be washed if user use different and incompatible medium.
1.8 The working temperature of WHDJ: Standard WHDJ operating temperature range is -15~80℃, high working temperature range of WHDJ is -10~200℃.
Selection of sample: five cylinder, system pressure 16 MPa and need to thrust 20KN, travel 5000, flange mounted, cylinder end stopper positioning, X=150, first top head with ear ring , at room temperature, the working medium of hydraulic oil,marked as WHDJF45/60/75/95/120-5000×150D

WHDJ series single acting multistage cylinder technical parameter list

2.WHDJ usage, maintenance, storage and maintenance
WHDJ the top of plunger rod is provided with air vent plug, it should be loosed and vent air when it is used for the first time. Crawling, vibration, jump phenomenon would happen if air isn’t vented completely inside cylinder, it also rust the sealing ring and shorten service lifetime.
WHDJ cylinder is strictly forbidden to bear the lateral force; long stroke WHDJ isn’t suitable to put at the horizontal direction . If you need multistage cylinder at more than two kinds of working conditions , please order a special design of the products.
The WHDJ cylinder should be filled with anti-rust oil or hydraulic oil if it isn’t used for a long time, and the oil port should be closed; and on all bare metal part anti-rust grease should be painted. All the plunger must be retracted final position; long stroke WHDJ cylinder should be vertically arranged. If there is no condition to put on standing position ,it could be laid on horizontal position ,but it should be turned over (180 degrees).at regular time once one month . WHDJ should be installed in the tank before the oil is drained, clean and then access system if it has been stored for a long time.
Eternal company also has a series of double action WHDJ multistage cylinder, but it must be designed and manufactured according to customers’ special features and special size. Such as high pressure, high speed, servo, large diameter and heavy load, long travel, with displacement monitoring, with a variety of functional valve block, with the terminal buffer, with travel, pressure switch, with electric hydraulic integrated device of multistage cylinder.

WHDJ Series Single Action Multistage Hydraulic Cylinder With Configuration Diagram

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