1. Archives and Tank.

2. It is like removing dirt, debris different parts of a hydraulic equipment, water or other debris attached to a hydraulic oil.

3. Is the cooling of hydraulic oil, a 4. To eliminate the bubbles caused by gushing oil to tank

 Design size of the hydraulic oil tank should be a provision for the size of the tank space above the fuel tank of approximately 10% of oil. The air bubbles to escape to creep out of the oil

Pipe flow to the hydraulic oil should be at a height below the tank about 2 inches and the end of a hydraulic pipe should form the mouth oblique Toward the wall of the tank That is because the oil will flow back toward the wall before running.

Which various contaminants attached to the oil hydraulic impact on a wall and agree below Then remove dirt, oil, which has removed some flow to the other side of the tank and remove the vacuum pump was used to. For other small pipe should be above the oil level. To prevent siphon while removing pipe to repair or replace the pipes are pipes of various pressure control valves etc.

Devices on the hydraulic tank F. Usually consists of the following is.

1. Motor (Electric Motor).

2. Hydraulic Pump F (Hydraulic Pump).

3. Valve Pressure Control (Pressure Countrol Valves).

4. Cooling device (Oil Cooler).

Filtration in a hydraulic system (Hydreulic Filtration).

Filtration in a hydraulic system is in two types.

1. Filtering harshly (Strainer).
2. Carefully filtered (Filter).

These filtration units with a second measurement is the value of mesh (Mesh) and measured in microns (Micron), but then most of us Units are typically found on a unit measurement over a micron mesh.

Micron pore size is the size of the filter as follows below.

1 micron = 1 / 1, 000 mm = 1 / 1, 000,000 meter = 0.00003937 inch.

Or to remember is simple.

1. 25 microns = 0.001 inch.
2. What the smallest visible to the naked eye is approximately 40 microns or more.
3. A human hair is approximately 70 microns.

Figure HYDRO-TANK-3

Shows the size of mesh and micron expanded 500 times.

Figure HYDRO-TANK-3 shows the size of mesh and micron expands 500 times and compare the size of other objects are micron, such as white blood cell approximately 25 microns red cells, approximately 8 microns the Interior (Cocci. ) approximately 2 microns and so on.

Filtration rate.

Strained Partners, one filter is dirty, size 25 microns almost all (approximately 98%), indicating that strained Partners This is normal if the dirt to grow to 40 microns, strained Partners is capable of filter. 100% strained called the Geneva Partners. Strained Partners with a complete filtration rate. (Must be strained partnership with the new conditions in the experiment).

 Filtration in a hydraulic system that Most will have the three points with a.
1. The filter vacuum pipe (Suction Side).
2. Filter pipe pressure (Pressure Side).
3. The oil filter pipe flow back (Return Side).

A suction tube and filter (Suction Sinde).

Filtration vacuum tube is often strained Partners serves to filter impurities. The rate of filtration from 75 microns to 240 microns size, but overall, always use a 125 micron filter is made of copper wire.

 2 filter pipe pressure (Pressure Side).

Filtering the suction pipe.

Since the metal impurities that occur in a hydraulic system that Usually caused by the friction of the parts of a hydraulic pump is mainly ¸.

Position the filter so that it would be best to exit the pump. By installing the oil filter before the Relief Valve. This type of filter must withstand the pressure of high pressure drop across the normal should be less than 15 pounds per square inch. If there are more than 30 pounds per square inch. Should change this filter.

The oil filter pipe pressure

Size of oil filters for pressure pipe size 10-25 micron filter material is often a paper Filters are often used with this system. The servo valve Or Proctor is on steep Null valve Which is expensive.

3 oil filter pipe flow back (Return Side).

1. The oil filter once flow back tank
2. Filters do not have to endure high pressure, much the price of oil filter properly.
3. Filter must be large enough to drain the oil into the tank with ease. And usually have enough Czech valve is installed in parallel.

Always oil the filter. The reason is the oil filter clogged whenever oil to flow into the tank will flow through the valve instead Czech (By Pass).

The oil filter pipe pressure

Size of the filter size to 10-25 microns, and usually made of paper.

4 filtering oil drain back Relief valve
Filters used this location for the drain oil through the Relief Valve time. Size of the filter are smaller and do not withstand much pressure because the flow rate was less than elsewhere. Pressure drop across should not exceed 3-5 pounds per square inch. Oil filter size of about 40 microns.

Oil filter back Relief valve

5 filter in the filter separately.
The filter will filter out a separate independent circuit. The low pressure pump to send oil through the filter, then remove the high pressure pump to run.

(Filter tank to complete and submit the same at the rate of 50-10% of the rate at which the pump is actually running the system to send) filtration is suitable only for large systems.

- Check equipment. Hydraulic systems installed in more appropriate placements available for use as filters, pumps, pressure limit valve, directional control valves, cylinders, pipe joint, gas, pipeline and etc..

2. Refueling.

- Make sure the tank room was already clean and free from impurities other waste materials.

- Fuel oil as guides or qualified as a specification to fill the tank without telling than the highest rating.

- In the case of tank capacity does not tell level. The fuel quantity required.

- The fuel should be added via a specific device for a filter is installed.

3. The starting system

- Open the valve closed – open the oil suction pipe in the first case of the installation in it.

- Adjust the valve to limit pressure in the open position flows into the oil tank room at low pressure. Or near zero

- Check the direction of rotation of the pump with the correct direction of rotation of the powered device. (Electric motors, engines), the pump is starting to follow most carefully. Especially lubricating oil, usually based on hydraulic pump that uses the c starting first often in the worst condition. Due to lack of flow of oil Therefore necessary to add fuel to fully pump before starting pump first, and for pump adjusts the flow rate was (Variable Displacement) should start walking at low pressure will best part of starting electric motors, it should be done by using triggered moment to ensure that the oil shock occurred. Distinguishable from the sound of the pump has changed. If the pump does not work to stop sending oil pump hire immediately. To prevent damage inspection of the oil viscosity. More typical oil filter and remove the jam Pump see nothing inside the pump to speed up work will be to check the oil level is higher than said low limit.

4. Punching the air.

- Due to air in the system resulting in wear and high interfere with other, so it is necessary to chase air from the system out after the start operation by the chase through the exit tube fittings in the open that the highest position of the system. We can observe that the exhausted air from the system. Based on the oil that flows out continuously at the open pipe. No oil in tank foam No sound system disorders. And equipment work. (Cylinder or motor – Hydraulic A) is functioning correctly.

5. And the pressure for use.

- Set pressure limit valve (Relief Valve) or pressure compensation valve (Pressure Compensating Valve) in the pump flow rate was adjusted. To control the maximum pressure of the system to suit the work load. Based on internal pressure on the pressure gauge. Which generally come from areas of origin. The pressure read at the source should be greater than the pressure that occurs destination (Pressure work that occurs when cylinder or motor Hydraulic acrylic work driving or driving load is) not much, or may say that should set the pressure at the source rather than the pressure drop across arising from the flow of oil at the source end นั่นเอง in practice to ensure that While the cylinders or hydraulic motors driving a loaded work. Limit pressure valve or valve pressure compensation. Must be open so that the adjustment is considered appropriate.

6. The accumulated power control pressure tank. (Accumulator).

- Tank pressure should be controlled to successfully accumulate energy in the first week of operation and in case of no leakage If the control can work as usual every year I check once a year to check the gauge pressure of the hydraulic system, a collection tank connected to power directly The compression test fuel tank to accumulate energy and then gradually release the gas pump stops the accumulation of power cylinder pressure under control. Observation of the pressure gauge. Indicator will fall to zero as soon as the pressure in the tank to accumulate energy before compression pressure before compression pressure reading from the first position the needle will fall to zero.

A seal damaged or missing piston alone can not be held responsible for the creeping stem of the cylinder, the seal gland end of the rod must also be damaged and leakage at the same time.

If the seal gland is damaged, then steals the stem downward by gravity and a heavy load, can make up fluid to start the vacuum that rod out of the cylinder, and moves in the free atmosphere. The presence of this liquid makeup can explore. Without it, the solution would be to create a team of space they would keep in place.

In this case, the makeup air is. The air is indeed a very useful liquid (no liquid) for use in bottles, especially if you do not mind vague, non-positive movement, and you do not operate at high pressures.

If the pole is pointing up or down, we learned that the lack of piston seal will not let blocked on a single rod cylinder with cylinder fluid drive or ports when the seal gland is rampant compromised.

If you know that your bottle is, in fact, if the ports seem to slip around the directional valve, and yet the end of the rod gland seal leakage is not allowed, where are the real cause?

The check valve of the management itself is often the cause. It can not be closed, the “A” and “B” cylinder ports operate completely. The valve may be worn or it is not because of his return to the position half-closed. The cause of valve problems will be covered in future newsletters.

Activity: Study and learning with simulate picture thus as below ,Understand Label prefill and decompression components. Complete sequencing of press controls .
The hydraulic press depends crucially Pascal pressure in a closed system is constant. At one end of the system, a piston is driven by a small cross-section of a lever to increase strength. Small-diameter pipe leads to the other end of the system. See the simulate picture thus as below .

Pascal’s Law: The pressure in a confined liquid is transmitted intact and acts with equal force on equal areas and 90 degrees to the vessel wall.

A liquid, as oil is displaced when the piston is pushed inward. The small piston for a given distance of movement, moves a smaller scale than the large piston, which is the ratio of the area of the piston head proportionately. Therefore, the small piston must be moved to move a large distance to the piston big to escape. The distance between the piston moves at great distance the piston moves, divided by the ratio of surface, the piston head. Thus energy is conserved in the form of work in this case and the law of conservation of energy is satisfied. Work is force multiplied by distance, and it increases with the force exerted on the piston greater the distance the force must be reduced excessively.

Here are some examples:

* Bale dryerPulp mill or plate for journalists
* Plywood Press
* Feed compactor

Picture1. Clamping Function

* Filter-press residue
Press * Aluminum extrusion profile
* Press Box
* Trash compactor

Decompression

At the end of the cycle the press ram material pressed, the fluid in the RAM is still under pressure. Properly control the speed of decompression than pull the ram is a serious problem that is common to most hydraulic presses. If you’ve ever heard, and believed that the hydraulic oil is not compressible, you must open your mind to some new learning. It is true that the hydraulic oil is not very compressible in comparison with gas such as air (used in plant air compressors), but this is not the end of history.

Picture2. controlling the rate of decompression

Without compression, so the available 400 Volume girl is filled with 400 gallons of hydraulic fluid.

Most heating oil hydraulic compression of about half of one percent per 1000 PSI hydraulic pressure. This means that at 1000 PSI, you can customize 502.5 gallons to 500 gallons ram. 5000 PSI, you can customize 512.5 gallons to 500 gallons of the same ram.
prefill3

The pressure, 512.5 gal were crammed into an area of 500 gal.

Typical work as an industrial printing press extruding aluminum and packaging pulp has a very large cylinder (or RAM) can have several gallons (10 liters) or more of the liquid completely compressed to the maximum pressure when fully deployed. This is a huge amount of potential energy.

Trap and pressure (5000 psi) The volume of 512.5 gallons of liquid in the RAM 500 gallons will print very quickly when the valve port opens to expose liquid to atmospheric pressure.

Under compression have been crammed into the 500 gal space.

Compress hydraulic fluids have been carried out gradually and controlled as the ram was moved against the load (feature extraction). The output of this compressed fluid must be carefully controlled. Decompression is usually treated by opening the valve a very small hole. Once atmospheric pressure has fallen to a level, the valve is opened for the cycle to withdraw quickly and efficiently.
prefill4

Decompression is begun with the opening doll relief, which allows controlled release of hydraulic fluid booster.

If the fluid is released at a pace not controlled as it is through the large port valve, which was immediately transferred to the highest position, the liquid moves at very high speeds. This outburst of energy cons wall tubes, which are essentially sub-during this period may cause pressure buildup in May of the same fracture line. Hose back in May diametrically boule sudden decompression of ram, and thus may contract length and separate installation or detachment of the wall surrounding the tank online.
hosedamage

Small diameter of the cylinder press, as used in trash compactors, food May appears decompression control. Those bottles with smaller volumes and lower pressures may be only a small amount of compressed fluid in the end of the race. Hydraulic components generally inexpensive to include only bang-bang style directional valve that releases fluid from the totally blind end port at the end of the cylinder stroke. The effects of uncontrolled decompression, it is still often heard and felt the shock wave is amplified by a metal cover the whole machine. Even these low volume shocks can have a devastating effect over time.

In the next issue of newsletter to learn, we will examine some specific decompression valve to control the vertical and horizontal presses.

Activity: Check and verify to Interpret catalogue data and operational specifications.

The debate over the control of hydraulic servo-valve was interesting. But the whole debate revolves around the ability to digital control of analog servo valve control. There are other considerations in the application of hydraulic servo valves for industrial applications.

Both the hydraulic cylinders and hydraulic servo-driven actuators have limited benefits of oil in compression (in the fall of oil). For cylinders the length of the race determines the oil trapped under the compression will be, and this determines the resonance will be hydraulically. A figure of merit than the resonance of not less than 200 rad / sec for a stable servant.

Hydraulic resonance = square root (2B ^ Dm 2/Jt Ve)
where B = compressibility = lb / in ^ 2
Dm = Motor displacement = ^ 3/rad
Jt = total inertia of the motor = lb-in-sec ^ 2
Ve = volume of oil under compression in ^ 3 =

To rotary actuators in which the valve of the servo is directly connected to the engine through a manifold, can hold around 60 Hz or more without a load on the engine. Most of the hydraulic servo can not bear any lateral load on the bearings in the end, the motor shaft. Therefore, a coupling device such as a Thomas joints needed to deviation from the crankshaft to minimize the load shaft. These links are much larger inertia inertia of the crankshaft. This requirement reflects the load inertia of the machine is connected to the engine also reduces the hydraulic resonance. The result of this tax, yet reduces the bandwidth of servo-hydraulic machine industry for about 15 to 20 Hz

In general, if a servo-drive is a requirement which he was very torquey power is not enough torque, the hydraulic servo-course. The unity of the criteria for sizing hydraulic servos found resonance hydraulic high enough. The servo-valve is a 2-stage device. The output stage is the placement of the coil of the motor. The input stage is one of a range torque electric motor and a very high impedance which must be accompanied in the servo valve controller. The servo valve amplifier can be designed in house if you know what you do or suppliers capable of this amp

Issue: A company needs to apply protective + 600 tons of force for their

Picture in real part

product, the company for over 15 hours at a time. Force required to ramp in increments of 100 pounds. Very bright. Highly corrosive environment.

Solution: A 14 “x 5000 psi cylinder bore tie rod is designed with the appropriate servo-controlled 5000 psi hydraulic system. Touch screen and / or remote PLC. At that time the budget.

Symptom: Pump Noisy

 1. Cause: Cavitation

     Corrections DESIGN: Enter a larger hose.

    Review procedures in the field: to use a filter larger intake, use of oil with lower viscosity.

     2. Cause: Restricted Admission.

         DESIGN corrections in revenue should be at least 50% larger than the exhaust. Place the pump does not exceed 24 inches above the oil level.

          Reviews in the area: Clean the air filter box.

          3. Cause: Loss of suction.

             Corrections DESIGN: Keep the lines of simple aspiration.

            Reviews in the area: pour oil on the joints when the pump is running and the common place where the pump is running low.

           4. Cause: Loss of air intake shaft packing.

               Corrections DESIGN: Use flexible drive coupling with Stiff tank top for rigidity. 

                 Reviews in the area: Lubricate or extension of the packaging. Precise alignment shaft pump.              

        5. Cause: air sucked into the system of dams.

               Corrections DESIGN: Insert the intake and exhaust pipes on both sides of the plate baffle. Minimum oil circuit to the pump.

              Reviews in the area: Raising the level of oil in the tank. Relief under the oil level. The oil has an anti-foam additive?

     A security company that makes ID cards for high security areas for the use of more than 500 tons of their product, pressing and ejection every 6 seconds.

Solution:

    A 8.0 “bore x 6500 psi cylinder drawbar cylinders are designed with PLC / servo, 7000 psi hydraulic system.

The excess heat was removed by means of PLC-controlled coolers. Low (75 dB The noise levels achieved. At the time, on budget .

Hydraulic cylinder repair

Now that we know how a hydraulic cylinder, we can delve into the reasons why falls overlook. Here are some common problems that can break a hydraulic cylinder or cause a malfunction. I will discuss possible solutions that can help rebuild or repair the hydraulic cylinder. Reading instruction manuals for equipment supplied by manufacturers carefully before proceeding.

First Problem : rod hydraulic cylinder piston is broken or bent!

Bent rods are a common cause of joint failure. Bending cylinder bars can be caused by the rod diameter or insufficient material strength, cylinder mounting bad deal or a combination. Once the rod bends, the excessive burden is placed on the seal resulting in premature failure of the joint. The permissible load for a cylinder rod in an existing application can be checked using the Euler formula. A detailed explanation of how to do this is contained in the hydraulic industry control.

Solution: If the coverage, you see the twisted cylinder or barrel of the bottle is broken, there is nothing more or less you can do. It is time to replace the cylinder. Forging a new stretcher or ironing, the piston rod is beyond your capabilities. So if this is the case, repairing the hydraulic cylinder is not possible.

Second Problem: The seal of the hydraulic cylinder is broken!

Solution: If the shaft seal is broken can be replaced. However, the opening of the entire cylinder assembly is needed. Let’s see how we go about it. Get a diagram hydraulic cylinder, if possible, because it will help to reassembly. These cards you get equipment manufacturers and can also make an impression. You can order a repair kit for your standard hydraulic cylinder which is driven by production companies. It contains parts of cylinder seals and other parts based on the number and type of cylinders in the car.

The assembly of the cylinder varies with the type of machine. Locate the first seal. Most are located around the shaft at one end. The rotor shaft entrance is accessible by unscrewing the cover on that side. Then loosen the ducts that carry the fluid in the chamber capable of releasing the pressure. This will allow you to remove the tree that otherwise can not be removed due to hydraulic pressure. Handle with care the trees and be careful not to scratch it. Unplug the piston shaft and replace the seal with parts from a repair kit. Make sure the gasket is correctly aligned. Oil all the parties after the installation and back together in exactly the reverse order.

Third Problem : Inflated Tubes
Ballooning of the cylinder tube is usually caused by insufficient wall thickness and / or resistance materials for pressure cylinder operation. Once the tube balloons, correct tolerance between the piston and the tube wall is lost and high pressure fluid bypasses the seal. This high velocity fluid can erode the seal and localized overheating caused by the pressure drop through the piston reduces the length of the seal.

Cylinder Hydraulic System Diagram (Click Here to See Detail)

Four Problem: The segments are damaged!

Solution: If the piston rings are damaged, they can also be replaced by disassembling the same procedure regarding the above problem. The piston rings must be removed and replaced with great care. Scraper rings and cylinder before putting it all together.

If you have a multiple cylinder, things are more complicated. It is best to consult a qualified technician before continuing. I hope this article gave you an idea of how to rebuild a hydraulic cylinder with ease. I always remember one rule while you are solving mechanical problems, not without a reason to take some action. In addition, the assembly studies and etiological framework of the car before going to repair. Repair of hydraulic cylinders may be a good learning experience for those who like the design of the machine.