Delivery of Hydraulic Cylinders to Europe
Sino Mechanical received RFQ from our client. After three months discussions for all technical specifications with our professional technical team, our client signed contract with us and send us PO for hydraulic cylinders, hydraulic pumping station and machining parts to support hydraulic cylinders. These hydraulic cylinders, hydraulic pumping station and machining parts to support hydraulic cylinders are to work with spillway gate and radial gate for hydro power projects(hydroelectric power projects). Hydro power projects(hydroelectric power projects) is one of the oldest and largest sources of renewable energy, which uses the natural flow of moving water to generate electricity.
If you are on a construction site and see a shiny metal rod that can be extended and retracted on some construction machinery, it is almost 100% a hydraulic cylinder.
What are hydraulic cylinders?
Hydraulic cylinders, also known as oil cylinders, rely on hydraulic pressure to drive loads to achieve linear motion. The hydraulic cylinder is the simplest and most widely used hydraulic actuator.
The number of hydraulic cylinders used accounts for more than 95% of the total market hydraulic actuators. The global market for hydraulic cylinders is about $10 billion per year.
Hydraulic cylinder are also know as hydraulic rams and are hydraulic actuators which creates linear movement by converting the hydraulic energy back to a mechanical movement. Hydraulic cylinders convert fluid energy into linear force.
A hydraulic cylinder is a tube that produces linear actuation utilizing hydraulic pressure.
A hydraulic cylinder is a hydraulic actuator that converts hydraulic energy into mechanical energy. A hydraulic cylinder performs linear reciprocating motion (or swing motion). The hydraulic cylinder has simple structure and reliable operation. Hydraulic cylinders are widely used in various mechanical hydraulic systems.
Small piston seals divide the two chambers of the hydraulic cylinder (rod chamber and rod chamber) into two different pressure zones. Hydraulic cylinders produce linear motion. It consists of a cylindrical cylinder with a piston rod that moves in and out of the cylinder. The range of motion of the piston is limited by the length of the cylinder. The piston seal divides the cylinder into two chambers: a rod chamber and a rodless chamber. If the rodless cavity is filled with oil, the piston rod will extend. Fill the rod cavity with oil, and the piston rod will retract.
Design of different types of hydraulic cylinder
Hydraulic cylinder is a very widely used structural form in hydraulic system. In order to design and use this type of cylinder correctly, you should master its characteristics, related applications and precautions.
1. Single Rod Hydraulic Cylinders This type of hydraulic cylinder has a piston rod on only one side of the piston. The effective active area on both sides of the piston is not equal. The larger the diameter of the piston rod, the greater the difference between the effective active areas on both sides of the piston. When the oil supply pressure is equal, the thrust force generated by the side without the piston rod is greater than the pull force generated by the side with the piston rod. In the case of the same flow rate, the pressure oil on the side without the piston rod makes the piston rod extend slower than the speed of the piston rod retracted by the pressure oil on the side with the piston rod.
Note: When the piston rod is extended, it can generate a large thrust. When the piston rod returns, it has a faster speed of movement. Therefore, it is very suitable for occasions that bear load in one direction and return quickly without load. The thicker the piston rod, the greater the difference between thrust and pull, slow and fast. The slow-speed advance and fast return of the hydraulic planer table are realized by using a single-piston-rod hydraulic cylinder.
(2) Double piston rod hydraulic cylinder The piston of this cylinder has piston rods on both sides. When the diameters of the two piston rods are the same and the oil supply pressure and flow rate are constant, the reciprocating speed and force of the pistons are also equal. It has better rigidity and stability due to two piston rods.
Note: It occupies a large range of space when working. Its working range is approximately equal to 3 times of the effective stroke length. This type of hydraulic cylinder is mostly used on the grinding machine table.
(3) The single-acting hydraulic cylinder is the simplest type of hydraulic cylinder. It can only supply pressure oil to one side of the piston. It outputs force in one direction. The movement in the opposite direction is accomplished according to the external force of the load, spring force, self-weight of the plunger rod or piston rod, etc. There is no hydraulic force in the opposite direction. Its advantage is to save hydraulic power and simplify the oil circuit.
Note: Neither the speed nor the magnitude of the force in the opposite direction can be controlled. The self-gravity, load force, and spring force that drive the piston rod or plunger rod back to move must be greater than the sum of the back pressure and the frictional resistance of each part of the hydraulic cylinder. For spring return hydraulic cylinders, the spring must have a certain working space to increase its volume.
Single-acting hydraulic cylinders are widely used in the positioning and clamping of machine tools, lifting of dump trucks, lifting of elevators, and ship lifting booms.
(4) Double-acting hydraulic cylinders are much more widely used than single-acting hydraulic cylinders. Pressure oil can be alternately supplied to both sides of the piston. It drives the piston to reciprocate. Its movement speed and oil supply pressure in both directions of pushing and pulling can be controlled. There are two kinds of double-acting hydraulic cylinders: single piston rod and double piston rod.
Note: The control system is more complex than single-acting hydraulic cylinders. Single-rod double-acting hydraulic cylinders are more commonly used than double-piston-rod double-acting hydraulic cylinders. The reciprocating hydraulic cylinders of the machine tool workbench and the various action hydraulic cylinders in construction machinery all use single-piston rod double-acting hydraulic cylinders.
(5) Most of the plunger cylinders are single-acting cylinders. It has a simple structure and is convenient to manufacture and maintain. The plunger of the plunger cylinder is thick, large and heavy. Its rigidity is better than that of the piston rod. Therefore, it is better to use this kind of cylinder in the hydraulic cylinder with large stroke. Because its cylinder inner wall is not in contact with the plunger. It is only guided by the contact between the guide sleeve and the plunger. The inner wall of the cylinder may not be machined or only rough machined. It has good process performance and low processing cost.
Note: The volume and weight of the plunger cylinder are relatively large. When installed horizontally, the column cold presses to one side, which is likely to cause unilateral wear of the seal and guide sleeve. Therefore, the plunger cylinder is suitable for vertical installation. When installed horizontally, a plunger bracket is required. This prevents the plunger from sagging and from bending. In addition, it can also prevent the phenomenon of "distortion" caused by increasing the initial deflection surface.
(6) Telescopic hydraulic cylinder Telescopic cylinder is also called multi-section cylinder, multi-stage cylinder or composite cylinder. It is available in single-acting and double-acting forms. The total stroke of this cylinder is long, and the length after contraction is very short. It is especially suitable for occasions where the installation space is small and the stroke is required to be long. For the same long stroke, the more the number of knots, the shorter the length after contraction.
Note: The more the number of sections, the greater the deflection of the hydraulic cylinder when it is extended. The structure becomes more complex. Moreover, the more difficult it is to manufacture, the higher the cost. Therefore, increase the number of sections only in exceptional circumstances.
Hydraulic Cylinder parts
The hydraulic cylinder is basically composed of cylinder barrel and cylinder head, piston and piston rod, sealing device, buffer device and exhaust device. Buffers and exhausts are application specific and others are essential.
1. Cylinder
The cylinder is the main part of the hydraulic cylinder.
It forms a closed cavity with cylinder head, piston and other parts. The cylinder barrel facilitates the movement of the piston. There are 8 types of common cylinder structures. Raw materials should have sufficient compressive strength and fracture toughness. And the raw material needs to have excellent welding properties for electric welding. Therefore, common raw materials are 25, 45, ZG200~400, 1Cr18Ni9, etc. Cylinder blanks are mostly cold-drawn or hot-rolled seamless tubes.
2. Piston
The piston is the key component that converts hydraulic energy into mechanical kinetic energy.
Its working area directly affects the efficiency and movement speed of the hydraulic cylinder.
There are various forms of connection between the piston and the piston rod. The common ones are snap ring, coupling type and nut type.
When there is no guide ring, the piston is made of high toughness pig iron HT200~300 or nodular casting
When there is a guide ring, the piston is made of high-quality alloy steel No. 20, No. 35 and No. 45.
3. Piston rod
The piston rod is the key component for transmitting force in a hydraulic cylinder.
The raw material generally chooses low carbon steel (such as No. 45 steel).
When the hydraulic cylinder is working, the piston rod is subject to driving force, tensile force or bending torque. Therefore, it is necessary to ensure the compressive strength of raw materials.
And the piston rod often rolls in the guiding sleeve. Therefore mutual fit should be suitable.
If the piston rod is tight, the sliding friction will be high. If the piston rod is too loose, it is very easy to cause a stuck condition and one-sided damage.
This requires its surface roughness, parallelism and concentricity to be suitable.
Therefore, the processing technology of the piston rod is generally rough turning → heat treatment → half boring → heat treatment → grinding before plating → stainless steel → grinding after plating → boring.
4. Cylinder head
The cylinder head is installed in the oil chamber formed by the hydraulic cylinder and the cylinder barrel.
Generally, there are various connection methods such as welding, thread, bolt, key and support rod. Therefore, it should be selected according to the working pressure, the interface mode of the hydraulic cylinder, and the use environment.
5. Orientation set
The guide sleeve acts as a guide and a support for the piston rod. It requires high precision, low friction and good wear resistance. It can bear the pressure, bending force and impact vibration of the piston rod. It is equipped with a sealing device to ensure the sealing of the cylinder rod cavity. Dust guards on both sides. This prevents debris, dust and moisture from getting into the leak-tight device and destroying the leak-tightness.
Metal guide sleeves generally use brass, gray cast iron, nodular cast iron and oxidized pig iron with small friction resistance and good wear resistance. Non-metal material guiding sleeves can be selected from polytetrafluoroethylene and polychlorotrifluoroethylene.
6. Cache device
The piston and piston rod have a very large projectile motion when they are driven by hydraulic pressure. When it enters the head and bottom part of the hydraulic cylinder, it will cause mechanical impact, resulting in very large impact pressure and noise.
The caching device is used to better avoid such collisions. Its principle is to make the oil in the cavity of the cylinder (part or part) convert kinetic energy into energy according to the throttle valve. The energy is sent out of the hydraulic cylinder by the oil in the circulation system. The structure of the buffer device is divided into two types: constant throttle area buffer device and manifold buffer device.
Types of hydraulic cylinder
There are various structural forms of hydraulic cylinders. There are many ways to classify it.
1. According to the motion mode, it can be divided into linear reciprocating motion type hydraulic cylinder and rotary swing type hydraulic cylinder.
2. According to the action of hydraulic pressure, it can be divided into single-acting hydraulic cylinder and double-acting hydraulic cylinder.
3. According to the structure, it can be divided into piston type hydraulic cylinder, plunger type hydraulic cylinder, multi-stage telescopic sleeve type hydraulic cylinder, rack and pinion type, etc.
4. According to the installation form, it can be divided into tie rods, earrings, feet, hinge shafts, etc.
5. According to the pressure level, hydraulic cylinder can be divided into 16Mpa, 25Mpa, 31.5Mpa and so on.
Hydraulic cylinder pump
Hydraulic cylinders, hydraulic power unit and hydraulic pumping station are mainly used in oil and gas industry, metallurgy, marine engines, machine tools, water conservancy and hydropower, engineering machinery, environmental protection machinery, military, aviation and other industries. Hydraulic cylinders, hydraulic power unit and hydraulic pumping station can be bused for different gate types include fixed wheel flat gate, radial gate, pipe gate, bulkhead gate, ship lock, landscape gate, etc.
What is hydraulic cylinder capacity?
Also known as hydraulic cylinder load lifting capacity, hydraulic cylinder force refers to the amount of force a cylinder can generate to lift a load or complete moving, pushing, pulling, and other tasks.
What are the standard hydraulic cylinder parameters (how to choose a hydraulic cylinder)?
The main parameters of the hydraulic cylinder include pressure, flow, size, piston stroke, movement speed, push-pull force, efficiency and hydraulic cylinder power. Today, the editor will talk about the parameters of standard hydraulic cylinders. Check out more detailed answers below!
1. The main parameters of the hydraulic cylinder include pressure, flow, size, piston stroke, movement speed, push-pull force, efficiency and hydraulic cylinder power.
2. Pressure is the pressure exerted by oil on a unit area.
Calculation formula p=F/A.
That is, the load acting on the piston divided by the effective working area of the piston. It can be seen from the above formula that the establishment of the pressure value is caused by the existence of the load.
3. The flow rate is the volume of the oil passing through the effective cross-sectional area of the cylinder per unit time.
Calculation formula Q=V/t=vA.
V represents the volume of oil consumed in one stroke of the hydraulic cylinder piston.
t represents the time required for one stroke of the hydraulic cylinder piston.
v represents the movement speed of the piston rod, and A represents the effective working area of the piston.
4. Piston stroke refers to the distance traveled between two poles when the piston reciprocates.
Generally, after meeting the stability requirements of the oil cylinder, select a standard stroke similar to the actual working stroke.
5. The movement speed is the distance that the pressure oil pushes the piston to move per unit time.
It can be expressed as v=Q/A.
6. Dimensions and specifications mainly include the inner and outer diameters of the cylinder, piston diameter, piston rod diameter and cylinder head size, etc.
These dimensions need to be calculated, designed and checked according to the use environment of the hydraulic cylinder, the installation form, the required push-pull force and stroke, etc.
7. When selecting a hydraulic cylinder, it should be remembered that the minimum length L of the hydraulic cylinder when the piston rod is fully retracted determines the installation space it requires.
8. The maximum distance X that the piston of the hydraulic cylinder can move is called the working stroke.
What should be paid attention to in the design of hydraulic cylinders?
(1) The design of hydraulic cylinders should try to avoid the use of non-standard sizes. Many sizes of hydraulic cylinders are designed according to specific needs. However, when selecting these dimensions, standard dimensions must be considered. In particular, the inner diameter of the cylinder, the diameter of the cylinder rod, and the dimensions related to the sealing ring cannot be selected arbitrarily according to actual needs, otherwise a suitable sealing ring may not be selected.
(2) The safety factor of the hydraulic cylinder should not be too small. The hydraulic cylinder must bear hydraulic pressure and mechanical force during the working process. At the same time, the uniformity of the material, stress concentration, machining accuracy and fatigue limit of the material are affected. This makes the working strength of the hydraulic cylinder vary widely. Therefore, there must be a sufficient safety factor, which should generally be above 5.
(3) The guide length of the piston rod should not be too small. The length of the guide sleeve generally varies with the size of the hydraulic cylinder and the type and use of the piston rod seal. But generally it should be more than 0.6 times the diameter of the piston rod. This ensures that the piston rod has sufficient stability.
(4) The guide sleeve of the high-speed and long-stroke hydraulic cylinder avoids the general structure. For hydraulic cylinders with a speed greater than 1000mm/s and a stroke of more than 4000mm, local overheating due to high-speed action. As a result, this causes considerable wear of the guide bushes and the appearance of metal dust. This not only enforces lubrication on the surface of the guide sleeve structurally. Moreover, special treatment such as high-frequency quenching is also required on the surface of the piston rod. At the same time, hydrostatic bearings can also be considered.
(5) Under the condition of ensuring that the motion stroke and load force can be satisfied, the outline size of the hydraulic cylinder should be avoided from being too large.
(6) Avoid the maximum load on the piston rod of the hydraulic cylinder under pressure. It should be ensured that it has good stability under pressure.
(7) The necessary shape and position tolerance of the cylinder cannot be ignored
In order to ensure that the hydraulic cylinder has a low starting pressure and does not have a "squeeze" phenomenon during movement, sufficient attention should be paid to the shape and position tolerance of the cylinder. In general, the roundness and cylindricity errors of the inner diameter of the cylinder should not be greater than half of the tolerance of the diameter of the cylinder. The straightness error of the cylinder axis is not more than 0.03mm per 500mm length. The circular runout of the cylinder end to the cylinder axis is no more than 0.04mm per 100mm.
(8) The position tolerance of the hydraulic cylinder earrings cannot be ignored
The position error of the earring hole of the earring hydraulic cylinder to the cylinder axis is not more than 0.03mm.
(9) The position tolerance of the pin shaft hydraulic cylinder cannot be ignored
The axial position tolerance of the pin-type hydraulic cylinder pin is not more than 0.1mm. Perpendicularity error is not greater than 0.1mm over a length of 100mm.
Price of Hydraulic Cylinders
The Hydraulic Cylinders Price will change randomly with factors such as production cost, transportation cost, international situation, exchange rate, market supply and demand of raw materials. Sino Mechanical aims to provide you with high quality and best price Hydraulic Cylinders. If you are looking for Hydraulic Cylinders or Hydraulic Cylinders spares, please kindly contact us to get the latest Hydraulic Cylinders price.
Hydraulic cylinder suppliers
Sino Mechanical, as leading hydraulic cylinder suppliers, has more than 20 years extensive experiences in the performance, application and cost-effective manufacturing of hydraulic cylinder. We are global hydraulic cylinder supplier and hydraulic cylinder company. Sino Mechanical provides a wide range of cylinders and offers below different types of hydraulic cylinder.
Welded hydraulic cylinders
Mill duty hydraulic cylinders
Tie rod hydraulic cylinders
Custom hydraulic cylinders
Single-acting hydraulic cylinders
Double-acting hydraulic cylinders
Large bore hydraulic cylinders
Tandem hydraulic cylinders
Stainless steel hydraulic cylinders
Duplex hydraulic cylinders
We have hydraulic cylinder for sale. Our factory has large capacity of machining spares. And we can produce as per your drawings and specifications. If you are looking for hydraulic cylinders, hydraulic power unit, hydraulic pumping station and machining spares from China with good price, high quality and fast delivery, send us your RFQ to sales@sinomechanical.com. We will get back to you with in 24 hours. We can also design and produce custom cylinders that meets your requirements.
