Hydraulic cylinders can be used to operate various mechanical devices. Using them to control machinery requires careful planning. For instance, a series of hydraulic cylinders will not function properly if one of them does not complete the stroke. It is also essential to choose the right type of hydraulic cylinder.
Problems with hydraulic cylinders if a cylinder does not stroke all the way
There are a few common reasons a hydraulic cylinder may not stroke all the way. First, the piston nut may be too loose, or the wear strip might be too worn. This can cause the piston to come loose from the rod, which can lead to a bypass of the seals. Other possible causes include damaged cylinder barrels and casings.
To ensure proper operation, you must use several cylinders to synchronize their strokes. To do this, ensure the cylinders are identical and set the cylinders’ maximum pressures and stroke times to match. Also, synchronize the cylinders to lock up and end their strokes.
Hydraulic cylinders are designed with locking safety features. Locking safety devices such as scotch keys or a set screw with a ball can be incorporated into the design of the hydraulic cylinder. Locking safety mechanisms such as these can help prevent accidental reversals or damage.
Ideally, hydraulic cylinders connected in series should be extended halfway. Then, they should be capped with a high-pressure plug. In addition, hydraulic pressure will extend the rod in the cylinder since the piston has a larger working area on the grow side.
You can also check to see if the cylinder has bypassed itself. In some cases, hydraulic cylinders will leak if the piston seals have not been used for a long time or are too worn. If they’ve worn out and have a low preload, there’s a high chance of a cylinder bypass.
There are many common reasons why a hydraulic cylinder may not fully stroke. Most cases, the fluid used to supply the cylinders is mineral oil-based. Some cylinders use fire-resistant water glycol-based fluids. These are often less lubricious than mineral oil. The sealing materials used in hydraulic cylinders must also be compatible with the fluid used in the cylinder.
In addition to the above, a hydraulic cylinder might drift. This can be caused by several factors, including a leak in a piston seal or an oversized piston. Regardless of the cause, the cylinder should be checked for equalization pressure before it becomes a problem.
When a hydraulic cylinder is connected in series, each cylinder must have enough power to lift the load to its full height. This synchronization is often affected by the bag’s position and the pressure drop across the needle valve. If the shipment is off-center, the oil transfer from the valve to the platen may not reach its target position, throwing the platen out of synchronization.
Problems with synchronizing hydraulic cylinders
If your hydraulic system is composed of two or more cylinders connected in series, synchronizing them is an important task. Without proper synchronization, your cylinders will exhibit undesirable behaviors. For example, they may creep when not in use, or they may not retract or extend at the same rate. This is not a good situation; you should address the problem as soon as possible.
There are several ways to synchronize two or more hydraulic cylinders. One method involves the use of a master-and-slave circuit. This circuit consists of one cylinder (C) that is mechanically linked to two cylinders (D) that share the same rod diameter, bore, and stroke. Another method involves using a backpressure check valve to keep the trapped oil volume full.
One common problem is that the two pumps are not identical, resulting in the cylinders being out of phase. This makes the hydraulic system inefficient. Similarly, when the pressure rises, the efficiency of the pumps decreases, as the valves and cylinder seals begin to leak and bypass. The solenoid that controls the flow between cylinders is also at risk of failure. This can cause the cylinder to start too late or operate incorrectly, resulting in poor performance and even damage the machine.
Another common problem with synchronizing hydraulic cylinders is the same as with single cylinders. The pressure in one cylinder must be enough to lift the entire load. If the shipment is too heavy for one cylinder, the pump dumps across the relief valve, and the other cylinder extends until the load damages the pump.
There are several ways to reduce or eliminate the synchronization error of double hydraulic cylinders. One solution is to use a fuzzy algorithm to eliminate displacement errors between double cylinders. This will reduce the position tracking error and eliminate oscillation in the control signal and hydraulic system. Using the fuzzy algorithm, you can eliminate the synchronization error to less than 0.15 mm.
Using the T or Y-dividers is another option for controlling hydraulic cylinders connected in series. This method uses two resistance scales, with the second resistance scale increasing as the cylinders move forward. This method can determine which cylinder is leading and which is lagging. It can also be used to control two control valves simultaneously.
Stalling is one of the most common problems with synchronizing hydraulic cylinders. If the load on one cylinder is greater than the other, it will cause both to stop working. When this happens, the energy in the other cylinders transfers through the hydraulic system. It will then try to force the lagging cylinder to work. It may even see a double force just before it stalls.
Types of hydraulic cylinders
Hydraulic cylinders are a popular option for many applications, including marine ones. These are often made from stainless steel and are coated with Hard Chrome Plating (HCP) to prevent corrosion. Other types of coating are available, such as COREX, which is ten times less porous than HCP, and Inconel, which is corrosion-resistant.
Single-acting hydraulic cylinders have one piston shaft and exert force in one direction. They raise arms, lift doors, and operate heavy machinery. Single-acting hydraulic cylinders are more straightforward and require less maintenance. One line actuates the piston rod, which is suitable for rugged equipment.
Cylinders are available in several types and sizes. The piston’s diameter and the cylinder’s bore will determine how intense the hydraulic pressure will be. Some hydraulic cylinders have long cylinders, while others have short cylinders. Cylinders with a long stroke are typically more durable than their shorter counterparts.
Hydraulic cylinders are also used in a variety of mobile applications. You can find them in heavy machinery, gym equipment, boats, and wheelchair lifts. They offer numerous benefits and are expected to grow significantly over the next few years. A few types of hydraulic cylinders are listed below.
Single-acting cylinders are designed to operate in one direction. The fluid in the cylinder pushes the hydraulic rod outwards while springs pull it back into the cylinder. On the other hand, tandem hydraulic cylinders operate in tandem and produce greater linear mechanical power than single-acting cylinders. They are connected to the same power source.
Telescopic cylinders consist of a series of single or double-acting cylinders. They are double-acting or single-acting and are used for lifting and lowering equipment. Telescopic cylinders are most commonly single-acting and use a spring mechanism for the return stroke.
These single-acting hydraulic cylinders have large rods that move up and down the cylinder. They are typically cheaper than conventional single-acting cylinders. They are commonly used in a horizontal or vertical motion. This is because they are cheaper to produce and use. However, they do have some limitations.
A hydraulic cylinder has a steel barrel made of honed or carbon steel. The cylinder’s steel barrels must be strong enough to resist the pressure of hydraulic fluid inside their walls. A hydraulic cylinder’s barrel wall thickness and precision tolerance will vary according to its intended application.
The hydraulic cylinders connected in series include single-acting and double-acting cylinders. Single-acting cylinders control movement by pressing on a piston rod in one direction, while double-acting cylinders press on both sides of the piston rod. Both types are common in material handling and raising/lowering devices.
The hydraulic fluid used in hydraulic systems is usually mineral oil-based. However, some hydraulic cylinders are made of fire-resistant water glycol-based fluid. While this fluid has a lower viscosity, it can still cause lubrication problems.