Hydrostatic Transmission Service, LLC offers hydrostatic and hydraulic repair and information for the following equipment and or parts
Hydraulic machinery are machines and tools which use fluid powerFluid power, also called hydraulic power is energy that is transmitted by pressurizing and controlling a contained fluid. The fluid may be a liquid as in hydraulics, or a gas as in pneumatics.
· Hydraulic machinery
· Information about Fluid Power is also available on the National Fluid Power Association web-site nfpa.
Heavy equipment hydraulicEngineering vehicles are heavy-duty vehicles, specially designed for executing engineering tasks.
· Hydraulic Backhoe loader
· Hydraulic Bulldozer
· Hydraulic Combat engineering vehicle (CEV)
· Hydraulic Compactor
· Hydraulic Crane
· Hydraulic Drag line excavator
· Hydraulic Excavator ("Bagger" or "Digger")
· Hydraulic Feller buncher
· Hydraulic Forklift
· Call Hydrostatic Transmission Service, LLC for all of your hydraulic or hydrostatic repair needs, we repair Sundstrand hydraulic, hydrostatic pumps motors transmissions drives equipment or components and parts or repair information.
In this type of machine, hydraulic fluidHydraulic fluids are a large group of liquids made of many kinds of chemicals. They are used in automobile automatic transmissions, brakes, and power steering; forklift trucks; tractors; bulldozers; industrial machinery; and airplanes. The three most common types of hydraulic fluids are mineral oil, organophosphate ester, and polyalphaolefin. Some of the trade names for hydraulic fluids include Durad®, Fyrquel®, Skydrol®, Houghton-Safe®, Pydraul®, Reofos®, Reolube®, and Quintolubric®. .....Click the link for more information.pumped to a high pressure and transmitted throughout the machine to various actuators. The hydraulic pump is powered by an engine An internal combustion engine is an engine that is powered by the expansion of hot combustion products of fuel directly acting within an engine. A piston internal combustion engine works by burning hydrocarbon or hydrogen fuel that presses on a piston; and a jet engine works as the hot combustion products press on the interior parts of the nozzle and combustion chamber, directly accelerating the engine forwards. The rotary combustion engine uses a rotor instead of reciprocating pistons. .....Click the link for more information.electric motor An electric motor converts electrical energy into mechanical motion. The reverse task, that of converting mechanical motion into electrical energy, is accomplished by a generator or dynamo. In many cases the two devices differ only in their application and minor construction details. Traction motors used on locomotives often perform both tasks if the locomotive is equipped with dynamic brakes. .....Click the link for more information.. Pressurized fluid is controlled by the operator with a control valve and distributed through hoses and tubes.
The popularity of hydraulic machinery is due to the very large amount of power that can be transferred through small tubes and flexible hoses, high power density, and wide array of actuators that can make use of this power.
The theory behind hydraulic equipment is fluid pressureFluid pressure is the pressure on an object submerged in a fluid, such as water. The pressure can be provided from a number of sources:
1. the shear weight of the fluid, such as in scuba diving, when the diver goes deeper into the water, the water pressure increases; or in the earth's atmosphere, as a plane goes higher, the air pressure decreases;
2. a pump, such as when water "pumped" into a water tower; or
3. a compressor, such as in a small water supply system in a rural well for a house connected to an air compressor.
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1. A force acting on a small area can create a much larger force by acting on a larger area by virtue of hydrostatic pressure.
2. A large amount of energy can be carried by a small flow of highly pressurized fluid.
Hydrostatic transmission service offers full service hydraulic and hydrostatic repair for Sundstrand, eaton ,dynapower , and rexroth pumps, motors ,transmissions, drives, equipment components and parts
Hydraulic machinery offers an incredible amount of power and force with relatively small components. A typical hydraulic cylinder with a 75 mm (3 inch) bore, for example, can supply 89 000 N (20,000 lbf The pound-force is a non-SI unit of force or weight (properly abbreviated "lbf" or "lbf"). The pound-force is equal to a mass of one pound multiplied by the standard acceleration due to gravity on Earth (which is defined as exactly 9.806 65 m/s², or exactly 196,133/6096 ft/s², or approximately 32.174 05 ft/s²). .....Click the link for more information.). The large amount of power transmitted in a hydraulic system is easily controlled with valves.
Some parts of a hydraulic system will operate at about 2000 kPa (300 psi) (pilot controls, vehicle brakes). The main hydraulic cylinders will usually operate in the range of 7000 - 40000 kPa (1000 - 6000 psi). Some exotic systems with titaniumTitanium is a chemical element in the periodic table that has the symbol Ti and atomic number 22. It is a light, strong, lustrous, corrosion-resistant (including resistance to sea water and chlorine) transition metal with a white-silvery-metallic color. Titanium is used in strong light-weight alloys (most notably with iron and aluminum) and its most common compound, titanium dioxide, is used in white pigments. .....Click the link for more information.will operate at over 350 000 kPa (50,000 psi).
In order for hydraulic fluid to do work it needs to flow to the actuator where it does work, and afterwards return to a reservoir. The fluid is then filtered and re-pumped.
The path taken by hydraulic fluid is called a circuit. An example is an open center circuit, where hydraulic fluid from the reservoir is drawn through a filter and then pumped. The fluid then goes through a hose to the main valve where it is returned to the reservoir, or, if the main valve is engaged, routed to a hydraulic cylinder. When the valve routes fluid to a cylinder it also provides a return path from the cylinder to the reservoir (see illustrations below). The pump will supply a constant volume of fluid; low pressure when returned to tank, and high enough pressure to maintain flow rate when resistance is met at an actuator doing work. Relief valves will keep the pressure from rising too high, in which case the actuator will stop moving and fluid will return to tank through a pressure relief valve.
The example above is called an open center circuit because the fluid returns to tank through the valve when centered. This type of circuit can use inexpensive, constant displacement pumps.
Another common circuit is load sensing or closed center, where the pump has a variable flow rate to improve efficiency. This design requires a pump that senses when the system needs greater flow, and has a mechanism to increase flow rate. Very little hydraulic fluid is pumped until the operator actuates a valve, so the valve's spool doesn't need an open center return path to tank.
Hydraulic pumps A pump is a mechanical device used to move liquids or gases.
The earliest pump was described by Archimedes around 300 BC and is known as the Archimedes screw pump. Pumps work by using mechanical forces to push the material, either by physically lifting, or by the force of compression.
Hydrostatic Transmission Service, LLC offers Sundstrand, Eaton, Dynapower, rexroth, Kawasaki, parts, pumps, motors, transmissions, drives, equipment and parts
Pumps fall into two categories: positive displacement pumps, which force fluid from one sealed chamber to another with little leakage, and dynamic pumps, which use the momentum of the fluid to move it across an unsealed chamber. .....Click the link for more information.a power density about ten times greater than an electric motor (by volume). They are connected to an engine through gears, belts, or sometimes a flexible elastomeric The term elastomer is often used interchangeably with the term rubber, and is preferred when referring to vulcanisates. They are amorphous polymers existing above their glass transition temperature, so that considerable segmental motion is possible. At ambient temperatures rubbers are thus relatively soft (E~3MPa) and deformable. Their primary uses are for seals, adhesives and molded flexible parts. .....Click the link for more information.to reduce vibration.
Common types of hydraulic pumps for hydraulic machinery applications are;
· gear pumpGear pumps use the meshing of gears to pump fluid by displacement. They are one of the most common types of pumps for hydraulic fluid power applications. There are two main variations; external gear pumps which use two external spur gears, and internal gear pumps which use an external and an internal spur gear......Click the link for more information., Cheap, durable, simple. Less efficient, because it does not have a variable flow rate.
· vane pump
· piston pump, can be designed for a variable flow rate. A swash plate rotates to stroke a bank of pistons. Very expensive, very high pressure capabilities. Piston pumps make up one half of a hydrostatic transmission
Directional control valves route the fluid to the desired actuator. They usually consist of a spool inside a cast iron3, 4, 6 (amphoteric oxide) Electronegativity 1.83 (Pauling scale) Ionization energies (more) 1st: 762.5 kJ/mol 2nd: 1561.9 kJ/mol 3rd: 2957 kJ/mol Atomic radius 140 pm Atomic radius (calc.) 156 pm Covalent radius 125 pm Miscellaneous Magnetic ordering ferromagnetic Electrical resistivity (20 °C) 96.1 nΩ·m .....Click the link for more information.steel
See Steel (disambiguation) for other uses.
Steel is a metal alloy whose major component is iron, with carbon being the primary alloying material. Carbon acts as a hardening agent, preventing iron atoms, which are naturally arranged in a lattice, from sliding past one another. .....Click the link for more information.. The spool slides to different positions in the housing, intersecting grooves and channels route the fluid based on the spool's position.
The spool has a central (neutral) position maintained with springs; in this position the supply fluid is blocked, or returned to tank. Sliding the spool to one side routes the hydraulic fluid to an actuator and provides a return path from the actuator to tank. When the spool is moved to the opposite direction the supply and return paths are switched. When the spool is allowed to return to neutral (center) position the actuator fluid paths are blocked, locking it in position.
Directional control valves are usually designed to be stackable, with one valve for each hydraulic cylinder, and one fluid input supplying all the valves in the stack.
Tolerances are very tight in order to handle the high pressure and avoid leaking, spools typically have a clearance with the housing of less than a thousandth of an inch. The valve block will be mounted to the machine's frame with a three point pattern to avoid distorting the valve block and jamming the valve's sensitive components.
The spool position may be actuated by mechanical levers, hydraulic pilot pressure, or solenoids In engineering, a solenoid is a mechanical device that converts energy into linear motion. Solenoids can be constructed to use electricity, compressed air (pneumatic solenoids), or pressurized fluids (hydraulic solenoids).
Electric solenoids consist of an inductive coil wound around a movable steel or iron slug. .....Click the link for more information.push the spool left or right. A seal An O-ring is a loop of elastomer with a round (o-shaped) cross-section used as a mechanical seal. They are designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface.
The joint may be static, or (in a few circumstances) have relative motion between parts and o-ring (rotating pump shafts and hydraulic cylinders, for example). Joints with motion usually require lubrication of the o-ring to reduce wear. This is often accomplished with the fluid being sealed. .....Click the link for more information.part of the spool to protrude outside the housing, where it is accessible to the actuator.
The main valve block is usually a stack of off the shelf directional control valves chosen by flow capacity and performance. Some valves are designed to be proportional (flow rate proportional to valve position), while others may be simply on-off. The control valve is one of the most expensive and sensitive parts of a hydraulic circuit.
Pressure relief valves are used in several places in hydraulic machinery; on the return circuit to maintain a small amount of pressure for brakes, pilot lines, etc... On hydraulic cylinders, to prevent overloading and hydraulic line/seal rupture. On the hydraulic reservoir, to maintain a small positive pressure which excludes moisture and contamination.
Pressure reducing valves reduce the supply pressure as needed for various circuits.
Counterbalance valves supply resistance to flow under certain conditions, to help a forklift maintain position of a load, for example.
Sequence valves control the sequence of hydraulic circuits; to insure that one hydraulic cylinder is fully extended before another starts its stroke, for example.
Shuttle valves provide a logical ordisjunction is an "or statement". For example "John skis or Sally swims" is a disjunction.
Note that in everyday language, use of the word "or" can sometimes mean "either, but not both" (e.g., "would you like tea or coffee?"). In logic, this is called an "exclusive disjunction" or "exclusive or" (xor). When used formally, "or" allows for both parts of the or statement (its disjuncts) to be true ("and/or"), therefore "or" is also called inclusive disjunction.1 .....Click the link for more information..
Check valvescheck valve is a mechanical device, a valve, that normally allows fluid to flow through it in only one direction. A double check valve is often used as a backflow prevention device to keep potentially contaminated water from siphoning back into municipal water supply lines. A clapper valve is a type of check valve used in or with firefighting, and has a hinged gate (often with a spring urging it shut) that will only remain open in the outflowing direction. .....Click the link for more information.are one way valves, allowing an accumulator to charge and maintain its pressure after the machine is turned off, for example.
Cartridge valves are off the shelf components with a standardized envelope, making them easy to populate a proprietary valve block. They are available in many configurations; on/off, proportional, pressure relief, etc. They generally screw into a valve block and are electrically controlled to provide logic and automated functions.
Hydraulic fuses In hydraulic systems, a fuse is a component which prevents the sudden loss of hydraulic fluid pressure. It is a safety feature, designed to allow systems to continue operating, or at least to not fail catastrophically, in the event of a system breach.
The term "fuse" is used here in analogy with electical fuses which perform a similar function. .....Click the link for more information.are in-line safety devices designed to automatically seal off a hydraulic line if it rapidly loses pressure.
Auxiliary valves. Complex hydraulic systems will usually have auxiliary valve blocks to handle various duties unseen to the operator, such as accumulator charging, cooling fan operation, air conditioning power, etc... They are usually custom valves designed for the particular machine, and may consist of a metal block with ports and channels drilled. Cartridge valves are threaded into the ports and may be electrically controlled by switches or a microprocessor to route fluid power as needed.
Hydrostatic Transmission Service. LLC offers Sundstrand , and Eaton hydrostatic, hydraulic valves, repair including electrical solenoids
· hydraulic cylinder
· rotary actuator (hydraulic)
· motor (a pump plumbed in reverse)
· hydrostatic transmission
Accumulator A hydraulic accumulator is an energy storage device. It is a pressure storage reservoir in which a non-compressible hydraulic fluid is held under pressure from an external source. That external source can be a spring, a raised weight, or a compressed gas.
Compressed gas accumulators are by far the most common type. These are also called hydropneumatic accumulators. .....Click the link for more information.s
Accumulators are a common part of hydraulic machinery, they store energy by using pressurized gas. One type is a tube with a floating piston. On one side of the piston is a charge of pressurized gas, on the other side is the fluid. Bladders are used in other designs.
Examples of accumulator uses are backup power for steering or brakes, or to act as a shock absorber for the hydraulic circuit.
Hydraulic fluidHydraulic fluids are a large group of liquids made of many kinds of chemicals. They are used in automobile automatic transmissions, brakes, and power steering; forklift trucks; tractors; bulldozers; industrial machinery; and airplanes. The three most common types of hydraulic fluids are mineral oil, organophosphate ester, and polyalphaolefin. Some of the trade names for hydraulic fluids include Durad®, Fyrquel®, Skydrol®, Houghton-Safe®, Pydraul®, Reofos®, Reolube®, and Quintolubric®. .....Click the link for more information.
Also known as tractor fluid, hydraulic fluid is the life of the hydraulic circuit. It is usually petroleum oil with various additives. Some hydraulic machines require fire resistant fluids, depending on their applications.
In addition to transferring energy, hydraulic fluid needs to lubricate Lubrication occurs when opposing surfaces are completely separated by a lubricant film.The applied load is carried by pressure generated within the fluid, and frictional resistance to motion arises entirley from the shearing of the visocus fluid. They are classified into three major categories. They are:1. Hydrodynamic lubrication, 2. .....Click the link for more information., suspend contaminants and metal filings for transport to the filter, and to function well to several hundred degrees Fahrenheit or Celsius.
Filters are a very important part of hydraulic machinery. Metal filings are continually produced by mechanical components and need to be removed, along with other contamination.
The filter is usually located between the reservoir and the pump. Blockage of the filter will cause cavitation Cavitation is the phenomenon where small cavities of partial vacuum form in fluid, then rapidly collapse, producing a sharp sound. It occurs in pumps, propellers, impellers, and the vascular tissues of plants.
Cavitation is the formation of pockets of vapor in a liquid. This process is caused by low pressures in the liquid. When the local ambient pressure at a point in the liquid falls below the liquid's vapor pressure, the liquid undergoes a phase change to a gas, creating "bubbles," or, more accurately, cavities, in the liquid. .....Click the link for more information.possibly failure of the pump. Sometimes the filter is located after the pump, and before the control valves. This arrangement is more expensive, since the pump housing is pressurized, but eliminates cavitation problems and protects the control valve from pump failures.
The hydraulic fluid reservoir holds excess hydraulic fluid to accommodate volume changes from: cylinder extension and contraction, temperature driven expansion and contraction, and leaks. The reservoir is also designed to aid in separation of air from the fluid. Design engineers are always pressured to reduce the size of hydraulic reservoirs, while equipment operators always appreciate larger reservoirs.
Some designs include dynamic flow channels on the fluid's return path that allow for a smaller reservoir.
Hose, tubes and pipes
Hydraulic hose is graded by pressure, temperature, and fluid compatibility. A rubber interior is surrounded by multiple layers of woven wire and rubber. The exterior is designed for abrasion resistance. The bend radius of hydraulic hose is carefully designed into the machine, since hose failures can be deadly, and violating the hose's minimum bend radius will cause failure. Hydraulic hoses generally have steel fittings swaged on the ends.
Hydraulic pipe is thick enough to have threads The word thread has many meanings:
· A thread is a kind of thin yarn, which is thin fibers spun together. It is used in manufacture of textiles and in sewing.
· "Thread" is another name for the blade of a propeller.
· A thread in computer science is a sequence of instructions which may execute in parallel with other threads.
.....Click the link for more information.into it for connections. It is rarely used for high pressure systems, which prefer tubes or hoses. Pipe lends itself to weldments and can used to fabricate manifolds. Steel suppliers carry black pipe, which is non-galvanized
Galvanize redirects here. "Galvanize" is also the name of a song by the Chemical Brothers.
Galvanization refers to any of several electrochemical processes named after the Italian scientist Luigi Galvani.
1. Originally, galvanization was the administration of electric shocks (in the 19th century also termed Faradism, after Michael Faraday).
.....Click the link for more information.suitable for weldingWelding is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, but sometimes pressure is used in conjunction with heat, or by itself, to produce the weld. This is in contrast with soldering and brazing, which involves melting a lower-melting-point material between the workpieces to form a bond between them. .....Click the link for more information..
Hydraulic tubes are preferred over hoses whenever possible, since they are more durable. They are also preferred to pipe since they weigh less. Hydraulic tubes usually have flared ends and captive nuts to make connections. They may also be steel weldments with floating nuts and face seal fittings on the ends. Tubes can be fabricatedFabrication is an industrial term generally applied to the building of metal machines and structures. The term is also used for semiconductor device fabrication and non-metal manufacturing . Small business that specialize in metal fabrication are called fab shops.
Fabrication shops and machine shops have overlapping capabilities, with fabrication shops concentrating on metal forming and welding. .....Click the link for more information.a high degree of complexity.
Tubes and pipes for hydraulic applications traditionally have not been plated or painted, since the oil and temperature they operate under drive away moisture and reduce rusting. Anti corrosion coatings, such as zinc chromate, are becoming more popular.
Hydrostatic Transmission Service, LLC offers Sundstrand hydraulic and hydrostatic services, and product design pump, motor, transmission, drives, equipment repair
Seals, fittings and connections
In general, valves, cylinders and pumps have female threaded bosses for the fluid connection, and hoses have female ends with captive nuts. A male-male fitting is chosen to connect the two. Many standardized systems are in use.
Fittings serve several purposes;
1. To bridge different standards; O-ring boss to JIC (hydraulic), or pipe threads to face seal, for example.
2. To allow proper orientation of components, a 90°, 45°, straight, or swivel fitting is chosen as needed. They are designed to be positioned in the correct orientation and then tightened.
3. To incorporate bulkhead hardware.
4. A quick disconnect fitting may be added to a machine without modification of hoses or valves
A typical piece of heavy equipment may have thousands of sealed connection points and several different types of seals, below are some of the most common types;
· Pipe fittings, the fitting is screwed in until tight, difficult to orient an angled fitting correctly without over or under tightening.
· O-ring boss, the fitting is screwed into a boss and orientated as needed, an additional nut tightens the fitting, washer and o-ring An O-ring is a loop of elastomer with a round (o-shaped) cross-section used as a mechanical seal. They are designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface.The joint may be static, or (in a few circumstances) have relative motion between parts and o-ring (rotating pump shafts and hydraulic cylinders, for example). Joints with motion usually require lubrication of the o-ring to reduce wear. This is often accomplished with the fluid being sealed......Click the link for more information.place.
· Flare seal, a metal to metal compression seal with a cone and flare mating.
· Face seal, metal flanges with a groove and o-ring are fastened together.
· Beam seal, an expensive metal to metal seal used mostly for aircraft.
· Swaged seals, tubes are connected with fittings that are swaged in place (non-serviceable). Primarily used in aircraft.
Elastomeric seals (O-ring boss and face seal) are the most common types of seals in heavy equipment and are capable of reliably sealing 6000+ psi of fluid pressure.
Hydraulics Hydraulicsis a branch of science and engineering concerned with the mechanical properties of liquids. It is part of the more general discipline of fluid power. The word "hydraulics" comes from the Greek word ὑδϱαυλικός (hydraulikos) which in turn comes from ὕδϱαυλος meaning water organ which in turn comes from ὕδωϱ (water) and αὐλός (pipe)......Click the link for more information.
· Hydraulic Hints & Trouble Shooting Guide General Product Support, Eaton Corporation, 300Kb pdf file
· On-line re-print of U.S. Army Field Manual 5-499
preview not available. Click the link for more information.
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