mt10 hydraulics presentation
TRANSCRIPT
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MT-10 in Hydraulic systems
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Basic Principles:
• Force that is applied at one point is transmitted to another point using an incompressible fluid.
• The fluid is almost always an oil of some sort.
• The force is almost always multiplied in the process.
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Fundamental laws of hydraulics:
• Hydraulic pumps create flow - not pressure.• Resistance to flow creates pressure.• Flow determines actuator speed.• Pressure determines actuator force.• Fluid under pressure takes the path of least
resistance. When fluid moves from an area of high pressure to an area of low pressure (pressure drop) without performing useful work, heat is generated.
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Damage to system
• Contaminated hydraulic fluid• Bad maintenance practices• Overheating
Common causes:
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Contaminants of hydraulic fluid include:
• solid particles• Sediments• air• water • other matter that impairs the function
of the fluid.
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How does MT-10 improve hydraulic working?
• Reduces friction in pump and valves• Reduces temperature• Works even when water contamination• Cleans blocked lines• Reduces particle wear
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How solid particle contamination accelerates wear of hydraulic components:
• When a pump or motor is worn or damaged, internal leakage increases and therefore the flow available to do useful work decreases
• The rate at which damage occurs is dependent on the internal clearance of the components within the system, the size and quantity of particles present in the fluid, and system pressure.
• Particles larger than the component's internal clearances are not necessarily dangerous.
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How solid particle contamination accelerates wear of hydraulic components:
• Particles the same size as the internal clearances cause damage through friction.
• The most dangerous particles in the long term are those that are smaller than the component's internal clearances.
• Particles as small as 10 microns (a grain of salt is 100 microns) can cause severe damage to a hydraulic system and particles smaller than 5 microns are highly abrasive. If present in sufficient quantities, these invisible 'silt' particles cause rapid wear, destroying hydraulic pumps and other components.
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How solid particle contamination accelerates wear of hydraulic components:
• The most dangerous particles in the long term are those that are smaller than the component's internal clearances. Particles as small as 10 microns (a grain of salt is 100 microns) can cause severe damage to a hydraulic system and particles smaller than 5 microns are highly abrasive. If present in sufficient quantities, these invisible 'silt' particles cause rapid wear, destroying hydraulic pumps and other components.
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Solid particles: Three-body abrasion
• When hydraulic fluid is contaminated with hard particles that are the same size as the clearance between two lubricated surfaces, a process known as three-body abrasion occurs.
• Three-body abrasion results in scoring and heavy wear of sliding surfaces
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• MT-10 changes the surface polarity of ferrous metal to positive
• Contaminates, such as wear particles, environmental dirt and oil precipitates all have a positive charge
• Therefore the MT-10 makes the metal surfaces repellant to these contaminants.
How does MT-10 help?
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• By making the surface polarity of ferrous metals positive the MT-10 will clean the metal surfaces
• The contaminates, will return/be reabsorbed into the oil
• This will INCREASE PPM of metal particles in the oil
• This may INCREASE oil viscosity
How does MT-10 help: Particles
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• Wear caused by particles leads to internal leaking
• The MT-10 stops particles adhering to the metal surfaces, thus reduces wear damage.
• The particles continue circulating with the oil where they can be trapped by the filters.
MT-10 in gear pumps
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Wear caused by inadequate installation of pump
• A common misconception among maintenance personnel with limited training in hydraulics, is that because oil circulates through hydraulic components in operation, no special attention is required during installation, beyond fitting the component and connecting its hoses. Nothing could be further from the truth.
• After a hydraulic motor is installed, its case should be filled with clean prior to start-up. Starting a piston-type motor or pump without doing so, is similar to starting an internal combustion engine with no oil in the crankcase - premature failure is pretty much guaranteed.
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How does MT-10 help: Pump installation
• The presence of MT-10 in the metal surfaces protects the pump even if installed with no oil.
• In 1998 we received a letter from a hydraulic pump repair specialist which stated:
– “A pump which is worked without oil takes only 15 seconds to seize with damage to the faces of the pump as well as bushings or bearings. Once MT-10 was applied to the hydraulic oil a test was run for 15 minutes with a constant pressure of 1000 P.S.I. and 40oC, with a displacement of 5 G.P.M.then the pump was operated without oil at 1750 R.P.M. during 3.5 minutes reaching temperatures of 250oC. We stopped the machine and let the hydraulic pump cool down. When disassembled the pump showed no signs of wear on the faces of the gears and no wear was found on the bearings or shafts in spite of the temperatures reached”
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Loss of lubrication: Two-body abrasion
• In gear piston designs, friction is generated by the meshing of the gear teeth. The teeth have to be an exact fit to avoid loss of pressure.
• In axial piston designs, the cylinder barrel is hydrostatically loaded against the valve plate. The higher the operating pressure, the higher the hydrostatic force holding the cylinder barrel and valve plate in contact. However, if operating pressure exceeds design limits or if the valve plate is not in proper contact with the cylinder barrel, the cylinder barrel separates from the valve plate. Once separation occurs, the lubricating film is lost, the two surfaces come into contact and a process known as two-body abrasion occurs.
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How does MT-10 help: Two-body abrasion
• The MT-10 will significantly reduce wear even when the lubricating film is lost.
• This will reduce to a minimum any chance of two-body abrasion
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Contaminants: Sediments
• When sediments are deposited within system tubing their effect is similar to cholesterol in a human body. The increased resistance to flow increases system pressure,
• Slowing down the system
• Requiring the pump to work harder.
• Leading to increased temperature of operation
• Sediments may also cause pistons or valves to jam.
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How does MT-10 help: System Obstruction
• MT-10’s effect of changing the surface polarity leads to a general cleaning of the system once the product is added to the oil
• Thus MT-10 is like ‘oatmeal’ for a hydraulic system and will unblock the tubes, reducing pressure on the pumps and allowing the machine to respond faster.
• The cleaning effect of MT-10 also will permit sticking parts to move smoothly and – if the problem is small wear particles – jammed parts to be freed and work again.
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Overheating
• Continuing to operate a hydraulic system when the fluid is over-temperature is similar to operating an internal combustion engine with high coolant temperature. Damage is guaranteed.
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High oil temperature:
• Reduces oil viscosity– Which provokes increased wear– Which Shortens parts service life
• Dries out seals and washers– Which allows oil to leak from pistons– Which also allows environmental
particles to enter hydraulic system
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Why do hydraulic systems overheat?
• Heating of hydraulic fluid in operation is caused by inefficiencies. Inefficiencies result in losses of input power, which are converted to heat. A hydraulic system's heat load is equal to the total power lost (PL) through inefficiencies and can be expressed as:– PLtotal = PLpump + PLvalves + PLplumbing +
PLactuators
• If the total input power lost to heat is greater than the heat dissipated, the hydraulic system will eventually overheat.
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Solving overheating problems
• There are two ways to solve overheating problems in hydraulic systems:
• Decrease heat load
• Increase heat dissipation
• Decreasing heat load is always the preferred option because it increases the efficiency of the hydraulic system.
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How does MT-10 help: Overheating
• Reducing friction in the pump reduces temperature
• Reducing friction in the valves reduces temperature
• Reducing blockages in the pipes reduces system pressure and increases pump efficiency, reducing temperature.
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Benefits of MT-10 : Overheating
• MT-10 helps oils maintain better viscosity
• Helps heat dissipation systems to continue working within acceptable limits
• Overheating dries out seals, reducing their flexibility and provoking oil leaks.
• When MT-10 reduces temperature it helps extend the life of seals, preventing leaks and the entry of contaminants into the system.
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Contaminants: Water • Water in hydraulic fluid can attack
certain seal materials, cause corrosion of metal surfaces, decrease lubricity in the fluid and decrease bearing life.
• For example, as little as .02% water mixed in with the hydraulic oil will reduce bearing life by 50%. (Source: Machine Design, July 1986, "How Dirt and Water Affect Bearing Life" by the Timken Bearing Company.) Water can enter the hydraulic system through worn pump, motor, and cylinder seals
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Benefits of MT-10: Water contamination
• MT-10 impregnates the metal surface so it does not wash out.
• MT-10 is heavier than water, allowing it to reach metal surfaces even if there is water contamination
• MT-10 contains sophisticated technology against corrosion, reducing significantly the risk of rusting in the case that oil is contaminated by water.
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Summary: How does MT-10 improve hydraulic working?
• Reduces friction in pump and valves• Reduces temperature• Works even when water contamination• Cleans blocked lines• Reduces particle wear• Reduces oxidation