Telescopic Hydraulic Cylinders

When a long-trajectory stroke is required within a restricted area, telescopic hydraulic cylinders may be used. These multi-stage cylinders can be underbody and frontal. Both types are seen in:

  • dump tracks and trailers,
  • dumping gears,
  • road-building and utility machinery,
  • diggers,
  • lifting and transportation machines.

The HydroCube Research & Production Enterprise profile includes design and production of telescopic hydraulic cylinders; we deliver reliable competitive products that can be adopted for severe operating conditions.

Features of the Operating Principle

Telescopic cylinder consists of in-serial connected sectional blocks where previous block is the piston rod for the next block. When retracted, the structure dimensions are very compact, but when extended, cylinder overhang is great enough. When system is pressurized, pistons, one by one, move until the stop. First, the outer piston with the greatest diameter strokes forward, then the next one.

Sometimes, in standard structures, there are six nested pistons. Each of them requires certain load, therefore, the pressure inside the system shall be adjusted with each subsequent piston extension. If quantity of telescopic joints is more, stable uniform load can’t be achieved. Optimal length of retracted cylinder is about 30±10% of maximum overhang length.

Operation is performed as per the selected mode – valve-operated or direct flow. As for the first one, special pressure valve shall be provided on the each piston bottom. Due to the valve adjustment, loaded system, first, actuates the main piston. As for the second, the system is actuated with unloaded piston and a lower frequency on O-rings.

Telescopic cylinders can be both single-acting and double-acting. 

Single-acting telescopic hydraulic cylinders

It extents under the pressure of the working fluid supplied to the piston and retracts to initial position under the action of gravity or other forces of a mechanical nature.

Such devices are convenient to use with an already existing return load on the piston-rod, for example, on cargo dump trucks, trailers, tipping devices. As soon as the hydraulic supply is stopped and the whole structure is extended, the cylinder sections begin to reverse and get retracted by the weight of the vehicle body.

Double-acting telescopic hydraulic cylinders can work in both directions.

These cylinders have a forward stroke organized as in single-acting structures. For retraction, there are specially positioned retract seals on each movable section. Using them, it is possible to return the system to its initial position when there is no outside return force.

In double-acting telescopic hydraulic cylinders, oil is supplied from above. When it gets between the adjacent pressurized cylinders, the smaller cylinder is forced to retract inside the greatest one. Then, the port for next section retraction opens. Retraction continuous until all cylinders are completely nested inside the main one.

Telescopic Hydraulic Cylinder in HydroCube

Due to the customized solution, it is possible to choose the design as close to the existing external conditions as possible. This contributes to the improved equipment capacity and service life, reduced fuel consumption and wear rate. The hydraulic cylinder, which is manufactured with strict adherence to the process technologies and under multilevel factory control, is insured against emergency situations that are always out of place.

The advantages of telescopic cylinders made in HydroCube:

  • Maximum reliability of extraction of each section is ensured by a stopper located on its rod.
  • Roller knurling and high-tech double-sided machining on a piston tube ensures minimal intersectional clearances.
  • For our hydraulic cylinders, we use seamless pipes made of high-quality steel grades that have high thresholds for dynamic shear and high tensile strength.
  • We have developed our own seal system of fiberglass and nylon rings which provides maximum protection against the dirt particles ingress into the cavity of the system.
  • All our products are successfully operated in the conditions of heat (+45оC) and cold (–50°C).

When required, we can solve more complex tasks connected with a special design, for example, the simultaneous extension of all sections which can allow obtaining constant speed and thrust (used in the drill heads) or combining the design with single and double acting sections for reliable positioning of the drilling unit.

New Feedback

Dear Konstantin Vyacheslavovich,

LLC LKM Group expresses respect to you and thanks you and your employees for the prompt and high-quality work, namely for the manufacture of a non-standard lifting table.

You have considered all our wishes, starting from the design and to production, and offered your technical solutions to meet our expectations. Currently, the equipment is commissioned and completely involved into the production process .

We wish you success and new achievements in the business.

RosEkoTeлkh LLC expresses its gratitude to RPE HydroCube LLC for meeting the delivery time for hydraulic equipment, namely hydraulic cylinders.

We would especially like to draw attention to the quality of the equipment that meets the standards, the hydraulic cylinders fit perfectly.

Throughout the whole duration of hydraulic cylinders production stage, RPE HydroCube staff proved to be professionals in their field, starting from the application processing department and to the production workshop.

We sincerely wish you success, fruitful work and prosperity in your work .

SmileGate LLC thanks Research and Production Enterprise HydroCube for timely delivery of the high-grade equipment.

We appreciate your attentive approach to any set tasks. For a long time , we were searching for a manufacturer of hydraulic equipment , which would have own turning facilities.

Through search system, we found the proper partner as RPE HydroCube LLC. We placed an order to develop and manufacture a hoist bridge. All the specialists of the company demonstrated high professional level, due to which the project was designed in accordance with our requirements and required documentation was developed.

RPE HydroCube LLC is reliable manufacturer and supplier who concerns about the partners.

SmileGate LLC sincerely hopes for future mutually beneficial cooperation and maintenance of business and friendship relations.

Metallurg SpetsDetal LLL sincerely thanks RPE HydroCube LLC. During the time of our cooperation , we noticed your competence, operativity and tendency to make you job in a good and timely manner .

Your company became for us an ideal of mutually beneficial cooperation. Particularly, we would like to thank your specialist who reply to any issue in a timely and detail manner .

In a short time , we purchase hydraulic equipment for в 50 and 100 tn press. All the products meet the requirements of standards and demonstrated the good order of operation.

We would like to maintain the cooperation with you and kindly ask you to inform us about your new possibilities in the field of the hydraulic equipment.

Thank you for high skills!

KondorStroi LLC thanks RPE HydroCube LLC for very tight lead-time and excellent quality of product.

During the cooperation, we had a chance to observe the high professional level of Research and Production Enterprise HydroCube’s specialists. They addressed all the tasks in timely and expert manner. In the shortest time, they delivered hydraulic cylinders – analogues of leading company “Duplomatic”.

In any time, by our request, managers of the company gave us detailed consultation. All the specialists have high professional level. The strictly met the due dates of manufacturing and supply.

KondorStroi LLC hopes for long-term and fruitful cooperation with you, because you are reliable commercial partner for us.

Federal Post Department of the Kirov District of FGUP Russian Post thanks RPE HydroCube LLC for manufacturing of lift-table for specialised shaft, 3400*1000*5500 mm. During

our collaboration, RPE HydroCube LLC demonstrated high professionality, competence and tendency to self-improvement. We cooperated in mutually-beneficial conditions. Company’s specialists rendered proficient, qualified and timely support addressing the tasks in due time. The supplied product was operated within the test period and may be assumed as reliable and compliant with high quality requirements.