A hybrid vehicle is one that uses two or more distinct types of power, such as submarines that use diesel when surfaced and batteries when submerged. Other means to store energy include pressurized fluid in hydraulic hybrids .
100-483: The Sasol Solar Challenge is a South African endurance challenge for solar-powered vehicles, with classes for hybrid vehicles , electric vehicles , and biofuel -powered vehicles as well. Recognised by the International Solarcar Federation, the first challenge was run in 2008, and every two years thereafter. The event covers roughly 2,500 km, but has set loops for teams to repeat, with
200-535: A 3D printed drive system and lightweight housing, altogether weighing less than 4.5 kg. Active cooling keeps plastic parts from softening. The prototype uses a regular electric bicycle charge port. Hybrid power trains use diesel–electric or turbo-electric to power railway locomotives, buses, heavy goods vehicles, mobile hydraulic machinery , and ships. A diesel / turbine engine drives an electric generator or hydraulic pump, which powers electric/hydraulic motors—strictly an electric/hydraulic transmission (not
300-533: A Leitra tricycle (European patent EP 1165188). Until 2005 they built several prototype SH tricycles and quadricycles . In 1999 Harald Kutzke described an "active bicycle": the aim is to approach the ideal bicycle weighing nothing and having no drag by electronic compensation. A SHEPB prototype made by David Kitson in Australia in 2014 used a lightweight brushless DC electric motor from an aerial drone and small hand-tool sized internal combustion engine , and
400-408: A hydrostatic transmission . Directional control valves route the fluid to the desired actuator. They usually consist of a spool inside a cast iron or steel housing. The spool slides to different positions in the housing, and 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
500-494: A series-hybrid using two motor-in-wheel-hub arrangements with an internal combustion generator set providing the electric power; Porsche's hybrid set two-speed records. While liquid fuel/electric hybrids date back to the late 19th century, the braking regenerative hybrid was invented by David Arthurs, an electrical engineer from Springdale, Arkansas, in 1978–79. His home-converted Opel GT was reported to return as much as 75 mpg with plans still sold to this original design, and
600-715: A "typical" older switching/yard engine. The advantages hybrid cars have for frequent starts and stops and idle periods apply to typical switching yard use. "Green Goat" locomotives have been purchased by Canadian Pacific , BNSF , Kansas City Southern Railway and Union Pacific among others. Railpower Technologies engineers working with TSI Terminal Systems are testing a hybrid diesel–electric power unit with battery storage for use in Rubber Tyred Gantry (RTG) cranes . RTG cranes are typically used for loading and unloading shipping containers onto trains or trucks in ports and container storage yards. The energy used to lift
700-499: A Proton-Exchange Membrane (PEM) fuel cell/lithium-ion battery hybrid system to power an electric motor, which is coupled to a conventional propeller. The fuel cell provides all power for the cruise phase of flight. During takeoff and climb, the flight segment that requires the most power, the system draws on lightweight lithium-ion batteries. The demonstrator aircraft is a Dimona motor glider, built by Diamond Aircraft Industries of Austria, which also carried out structural modifications to
800-445: A common example. In this type of machine, hydraulic fluid is pumped to various hydraulic motors and hydraulic cylinders throughout the machine and becomes pressurized according to the resistance present. The fluid is controlled directly or automatically by control valves and distributed through hoses, tubes, or pipes. Hydraulic systems, like pneumatic systems , are based on Pascal's law which states that any pressure applied to
900-526: A constant RPM for peak efficiency. In 1978 students at Minneapolis, Minnesota's Hennepin Vocational Technical Center, converted a Volkswagen Beetle to a petro-hydraulic hybrid with off-the shelf components. A car rated at 32 mpg was returning 75 mpg with the 60 hp engine replaced by a 16 hp engine, and reached 70 mph. In the 1990s, engineers at EPA's National Vehicle and Fuel Emissions Laboratory developed
1000-413: A floating piston. On the one side of the piston there is a charge of pressurized gas, and on the other side is the fluid. Bladders are used in other designs. Reservoirs store a system's fluid. Examples of accumulator uses are backup power for steering or brakes, or to act as a shock absorber for the hydraulic circuit. Also known as tractor fluid , hydraulic fluid is the life of the hydraulic circuit. It
1100-429: A fluid inside a closed system will transmit that pressure equally everywhere and in all directions. A hydraulic system uses an incompressible liquid as its fluid, rather than a compressible gas. The popularity of hydraulic machinery is due to the large amount of power that can be transferred through small tubes and flexible hoses, the high power density and a wide array of actuators that can make use of this power, and
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#17327808405491200-403: A gasoline-electric hybrid rail-car propulsion system in early 1889, and for a similar hybrid boat propulsion system in mid 1889. There is no evidence that his hybrid boat met with any success, but he built a prototype hybrid tram and sold a small hybrid locomotive . In 1899, Henri Pieper developed the world's first petro-electric hybrid automobile. In 1900, Ferdinand Porsche developed
1300-526: A generally compact electric motor (usually <20 kW) to provide auto-stop/start features and to provide extra power assist during the acceleration, and to generate on the deceleration phase (also known as regenerative braking ). On-road examples include Honda Civic Hybrid , Honda Insight 2nd generation, Honda CR-Z , Honda Accord Hybrid , Mercedes Benz S400 BlueHYBRID , BMW 7 Series hybrids, General Motors BAS Hybrids , Suzuki S-Cross , Suzuki Wagon R and Smart fortwo with micro hybrid drive. In
1400-507: A generator charging the batteries. Modern versions such as the Toyota Hybrid Synergy Drive have a second electric motor/generator connected to the planetary gear. In cooperation with the traction motor/generator and the power-split device, this provides a continuously variable transmission. Hydraulic machinery Hydraulic machines use liquid fluid power to perform work. Heavy construction vehicles are
1500-764: A hybrid engine. The engine uses a mixture of compressed air and gasoline injected into the cylinders. A key aspect of the hybrid engine is the "active chamber", which is a compartment heating air via fuel doubling the energy output. Tata Motors of India assessed the design phase towards full production for the Indian market and moved into "completing detailed development of the compressed air engine into specific vehicle and stationary applications". Petro-hydraulic configurations have been common in trains and heavy vehicles for decades. The auto industry recently focused on this hybrid configuration as it now shows promise for introduction into smaller vehicles. In petro-hydraulic hybrids,
1600-448: A hybrid), unless it can accept power from outside. With large vehicles, conversion losses decrease and the advantages in distributing power through wires or pipes rather than mechanical elements become more prominent, especially when powering multiple drives—e.g. driven wheels or propellers. Until recently most heavy vehicles had little secondary energy storage, e.g. batteries/ hydraulic accumulators —excepting non-nuclear submarines , one of
1700-413: A hydraulic rotary pump with the displacement 10 cc/rev is connected to a hydraulic rotary motor with 100 cc/rev, the shaft torque required to drive the pump is one-tenth of the torque then available at the motor shaft, but the shaft speed (rev/min) for the motor is also only one-tenth of the pump shaft speed. This combination is actually the same type of force multiplication as the cylinder example, just that
1800-426: A network of tubes of coolant in a thermodynamic system) or to control fluid pressure (as in hydraulic amplifiers). For example, hydraulic machinery uses hydraulic circuits (in which hydraulic fluid is pushed, under pressure, through hydraulic pumps , pipes, tubes, hoses, hydraulic motors , hydraulic cylinders , and so on) to move heavy loads. The approach of describing a fluid system in terms of discrete components
1900-490: A partnership can be arranged. Another form of a hybrid vehicle are the human-powered electric vehicles. These include such vehicles as the Sinclair C5 , Twike , electric bicycles , electric skateboards , and Electric motorcycles and scooters In a parallel hybrid vehicle, an electric motor and an internal combustion engine are coupled such that they can power the vehicle either individually or together. Most commonly
2000-601: A petro-hydraulic powertrain for a typical American sedan car. The test car achieved over 80 mpg on combined EPA city/highway driving cycles. Acceleration was 0-60 mph in 8 seconds, using a 1.9-liter diesel engine. No lightweight materials were used. The EPA estimated that produced in high volumes the hydraulic components would add only $ 700 to the cost. Under EPA testing, a hydraulic hybrid Ford Expedition returned 32 mpg (7.4 L/100 km) City, and 22 mpg (11 L/100 km) highway. UPS currently has two trucks in service using this technology. Since 1985,
2100-408: A power-split hybrid electric drive train, there are two motors: a traction electric motor and an internal combustion engine. The power from these two motors can be shared to drive the wheels via a power split device, which is a simple planetary gear set. The ratio can be from 100% for the combustion engine to 100% for the traction electric motor, or anything in between. The combustion engine can act as
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#17327808405492200-424: A problem due to limited exchange of oil flow. High power closed loop systems generally must have a 'flush-valve' assembled in the circuit in order to exchange much more flow than the basic leakage flow from the pump and the motor, for increased cooling and filtering. The flush valve is normally integrated in the motor housing to get a cooling effect for the oil that is rotating in the motor housing itself. The losses in
2300-399: A test bed to prove viability. The BMW 530i gave double the mpg in city driving compared to the standard car. This test was using the standard 3,000 cc engine, with a smaller engine the figures would have been more impressive. The design of petro-hydraulic hybrids using well sized accumulators allows downsizing an engine to average power usage, not peak power usage. Peak power is provided by
2400-480: A typical American sedan car. The test car achieved over 80 mpg on combined EPA city/highway driving cycles. Acceleration was 0-60 mph in 8 seconds, using a 1.9 L diesel engine. No lightweight materials were used. The EPA estimated that produced in high volumes the hydraulic components would add only $ 700 to the base cost of the vehicle. The petro-hydraulic hybrid system has a faster and more efficient charge/discharge cycling than petro-electric hybrids and
2500-409: A unique trademark depending on the manufacturer of the valves, for example "LSC" (Linde Hydraulics), "LUDV" ( Bosch Rexroth Hydraulics) and "Flowsharing" (Parker Hydraulics) etc. No official standardized name for this type of system has been established but flowsharing is a common name for it. Hydraulic pumps supply fluid to the components in the system. Pressure in the system develops in reaction to
2600-405: A variety of fuels, generally gasoline or Diesel engines ) and electric motors to power the vehicle. The energy is stored in the fuel of the internal combustion engine and an electric battery set . There are many types of petroleum-electric hybrid drivetrains , from Full hybrid to Mild hybrid , which offer varying advantages and disadvantages. William H. Patton filed a patent application for
2700-424: A vehicle establishes contact with an electrified rail, plate, or overhead wires on the highway via an attached conducting wheel or other similar mechanisms (see conduit current collection ). The vehicle's batteries are recharged by this process—on the highway—and can then be used normally on other roads until the battery is discharged. For example, some of the battery-electric locomotives used for maintenance trains on
2800-423: Is a very rare mass-produced diesel hybrid vehicle powered by a Mercedes-Benz OM651 engine developing 152 kW (204 hp) paired with a 20 kW (27 hp) electric motor, positioned between the engine and the gearbox, for a combined output of 170 kW (228 hp). The vehicle has a fuel consumption rate of 24–26 km/L (56–62 mpg ‑US ; 67–74 mpg ‑imp ). These types use
2900-570: Is also cheaper to build. The accumulator vessel size dictates total energy storage capacity and may require more space than an electric battery set. Any vehicle space consumed by a larger size of accumulator vessel may be offset by the need for a smaller sized charging engine, in HP and physical size. Research is underway in large corporations and small companies. The focus has now switched to smaller vehicles. The system components were expensive which precluded installation in smaller trucks and cars. A drawback
3000-403: Is around 2 MPa (290 psi). If the pump flow is high the extra loss can be considerable. The power loss also increases if the load pressures vary a lot. The cylinder areas, motor displacements and mechanical torque arms must be designed to match load pressure in order to bring down the power losses. Pump pressure always equals the maximum load pressure when several functions are run simultaneously and
3100-720: Is charged when in low energy demanding vehicle operation. The charging engine runs at optimum speed and load for efficiency and longevity. Under tests undertaken by the US Environmental Protection Agency (EPA), a hydraulic hybrid Ford Expedition returned 32 miles per US gallon (7.4 L/100 km; 38 mpg ‑imp ) City, and 22 miles per US gallon (11 L/100 km; 26 mpg ‑imp ) highway. UPS currently has two trucks in service using this technology. Although petro-hydraulic hybrid technology has been known for decades and used in trains as well as very large construction vehicles,
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3200-519: Is inspired by the success of electrical circuit theory . Just as electric circuit theory works when elements are discrete and linear, hydraulic circuit theory works best when the elements (passive components such as pipes or transmission lines or active components such as power packs or pumps ) are discrete and linear. This usually means that hydraulic circuit analysis works best for long, thin tubes with discrete pumps, as found in chemical process flow systems or microscale devices. The circuit comprises
3300-418: Is one of the most expensive and sensitive parts of a hydraulic circuit. 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 and also work as a heat accumulator to cover losses in the system when peak power
3400-418: Is stainless steel. Components of a hydraulic system [sources (e.g. pumps), controls (e.g. valves) and actuators (e.g. cylinders)] need connections that will contain and direct the hydraulic fluid without leaking or losing the pressure that makes them work. In some cases, the components can be made to bolt together with fluid paths built-in. In more cases, though, rigid tubing or flexible hoses are used to direct
3500-414: 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. The weakest part of the high pressure hose is the connection of
3600-416: Is to create a blank paper design new car, to maximize the packaging of petro-hydraulic hybrid components in the vehicle. All bulky hydraulic components are integrated into the chassis of the car. One design has claimed to return 130 mpg in tests by using a large hydraulic accumulator which is also the structural chassis of the car. The small hydraulic driving motors are incorporated within the wheel hubs driving
3700-402: Is used. Reservoirs can also help separate dirt and other particulate from the oil, as the particulate will generally settle to the bottom of the tank. Some designs include dynamic flow channels on the fluid's return path that allow for a smaller reservoir. Accumulators are a common part of hydraulic machinery. Their function is to store energy by using pressurized gas. One type is a tube with
3800-410: Is usually a major problem when using hydrostatic transmissions at high vehicle speeds for longer periods, for instance when transporting the machine from one work place to the other. High oil temperatures for long periods will drastically reduce the lifetime of the transmission. To keep down the oil temperature, the system pressure during transport must be lowered, meaning that the minimum displacement for
3900-410: Is usually petroleum oil with various additives. Some hydraulic machines require fire resistant fluids, depending on their applications. In some factories where food is prepared, either an edible oil or water is used as a working fluid for health and safety reasons. In addition to transferring energy, hydraulic fluid needs to lubricate components, suspend contaminants and metal filings for transport to
4000-538: Is wasted for idling: ≈60–85% of the time for these types of locomotives. It is unclear if regenerative braking is used; but in principle, it is easily utilized. Since these engines typically need extra weight for traction purposes anyway the battery pack's weight is a negligible penalty. The diesel generator and batteries are normally built on an existing "retired" "yard" locomotive's frame. The existing motors and running gear are all rebuilt and reused. Fuel savings of 40–60% and up to 80% pollution reductions are claimed over
4100-683: The KiHa E200 , with roof-mounted lithium-ion batteries . India Indian railway launched one of its kind CNG -Diesel hybrid trains in January 2015. The train has a 1400 hp engine which uses fumigation technology. The first of these trains is set to run on the 81 km long Rewari-Rohtak route. CNG is less-polluting alternative for diesel and petrol and is popular as an alternative fuel in India. Already many transport vehicles such as auto-rickshaws and buses run on CNG fuel. North America In
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4200-504: The Saturn Vue , Toyota Prius , Toyota Yaris , Toyota Camry Hybrid , Ford Escape Hybrid , Ford Fusion Hybrid , Toyota Highlander Hybrid , Honda Insight , Honda Civic Hybrid , Lexus RX 400h , and 450h , Hyundai Ioniq Hybrid , Hyundai Sonata Hybrid , Hyundai Elantra Hybrid , Kia Sportage Hybrid , Kia Niro Hybrid , Kia Sorento Hybrid and others. A petroleum-electric hybrid most commonly uses internal combustion engines (using
4300-511: The energy recovery rate is high and therefore the system is more efficient than electric battery charged hybrids using the current electric battery technology, demonstrating a 60% to 70% increase in energy economy in US Environmental Protection Agency (EPA) testing. The charging engine needs only to be sized for average usage with acceleration bursts using the stored energy in the hydraulic accumulator, which
4400-416: The "Mother Earth News" modified version on their website. The plug-in-electric-vehicle (PEV) is becoming more and more common. It has the range needed in locations where there are wide gaps with no services. The batteries can be plugged into house (mains) electricity for charging, as well being charged while the engine is running. Some battery electric vehicles can be recharged while the user drives. Such
4500-463: The CP system. The LS system generates a constant power loss related to the regulating pressure drop for the pump regulator : Power loss = Δ p LS ⋅ Q tot {\displaystyle {\text{Power loss}}=\Delta p_{\text{LS}}\cdot Q_{\text{tot}}} The average Δ p L S {\displaystyle \Delta p_{LS}}
4600-484: The Kenworth T270 Class 6 that for city usage seems to be competitive. FedEx and others are investing in hybrid delivery vehicles—particularly for city use where hybrid technology may pay off first. As of December 2013 FedEx is trialling two delivery trucks with Wrightspeed electric motors and diesel generators; the retrofit kits are claimed to pay for themselves in a few years. The diesel engines run at
4700-494: The London Underground are capable of this mode of operation. Developing an infrastructure for battery electric vehicles would provide the advantage of virtually unrestricted highway range. Since many destinations are within 100 km of a major highway, this technology could reduce the need for expensive battery systems. However, private use of the existing electrical system is almost universally prohibited. Besides,
4800-539: The Netherlands ( Brunel Solar Team previously known as Vattenfall/Nuon). The primary objective is to design, manage, build and race solar-powered vehicles across South Africa. The challenge sees a collaboration between pupils, students, private individuals and various industry and government partners, to work together to have a safe, technology-rich event. Moreover, the challenge is seen as an educational tool to focus on and communicate about science and technology to
4900-451: The US military has been testing serial hybrid Humvees and have found them to deliver faster acceleration, a stealth mode with low thermal signature , near silent operation, and greater fuel economy. Ships with both mast-mounted sails and steam engines were an early form of a hybrid vehicle. Another example is the diesel–electric submarine . This runs on batteries when submerged and
5000-494: The US, General Electric made a locomotive with sodium–nickel chloride (Na-NiCl 2 ) battery storage. They expect ≥10% fuel economy. Variant diesel electric locomotive include the Green Goat (GG) and Green Kid (GK) switching/yard engines built by Canada's Railpower Technologies , with lead acid (Pba) batteries and 1000 to 2000 hp electric motors, and a new clean-burning ≈160 hp diesel generator. No fuel
5100-592: The accumulator. A small fossil-fuelled piston engine sized for average power use charges the accumulator. The accumulator is sized at running the car for 15 minutes when fully charged. The aim is a fully charged accumulator that will produce a 0-60 mph acceleration speed of under 5 seconds using four wheel drive. In January 2011 industry giant Chrysler announced a partnership with the US Environmental Protection Agency (EPA) to design and develop an experimental petro-hydraulic hybrid powertrain suitable for use in large passenger cars. In 2012 an existing production minivan
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#17327808405495200-426: The aircraft. With a wingspan of 16.3 meters (53 feet), the airplane will be able to cruise at about 100 km/h (62 mph) on power from the fuel cell. Hybrid FanWings have been designed. A FanWing is created by two engines with the capability to autorotate and landing like a helicopter. When the term hybrid vehicle is used, it most often refers to a Hybrid electric vehicle . These encompass such vehicles as
5300-491: The batteries can be recharged by the diesel engine when the craft is on the surface. As of 2022 , there are 550 ships with an average of 1.6 MWh of batteries. The average was 500 kWh in 2016. Newer hybrid ship-propulsion schemes include large towing kites manufactured by companies such as SkySails . Towing kites can fly at heights several times higher than the tallest ship masts, capturing stronger and steadier winds. The Boeing Fuel Cell Demonstrator Airplane has
5400-525: The broad public. The Dutch Brunel Solar Team finished first, the Belgian Innoptus Solar Team which participated for the first time became second with 38km difference and bronze went to Sunchaser, from South African university TUT . Hybrid vehicle Hybrid powertrains are designed to switch from one power source to another to maximize both fuel efficiency and energy efficiency . In hybrid electric vehicles , for instance,
5500-547: The containers can be partially regained when they are lowered. Diesel fuel and emission reductions of 50–70% are predicted by Railpower engineers. First systems are expected to be operational in 2007. Hybrid systems are regularly in use for trucks, buses and other heavy highway vehicles. Small fleet sizes and installation costs are compensated by fuel savings, with advances such as higher capacity, lowered battery cost, etc. Toyota, Ford, GM and others are introducing hybrid pickups and SUVs. Kenworth Truck Company recently introduced
5600-459: The diesel engine rpm while reducing the vehicle speed in order to increase the available hydraulic power output for the working hydraulics at low speeds and increase the tractive effort. The function is similar to stalling a converter gearbox at high engine rpm. The inch function affects the preset characteristics for the 'hydrostatic' gear ratio versus diesel engine rpm. The closed center circuits exist in two basic configurations, normally related to
5700-407: The efficiency and developments in the software have also improved the characteristics, for example selectable gear shifting programs during operation and more gear steps, giving them characteristics close to the hydrostatic transmission. Hydrostatic transmissions for earth moving machines, such as for track loaders, are often equipped with a separate ' inch pedal ' that is used to temporarily increase
5800-448: The electric motor is more efficient at producing torque, or turning power, while the combustion engine is better for maintaining high speed. Improved efficiency, lower emissions, and reduced running costs relative to non-hybrid vehicles are three primary benefits of hybridization. Mopeds , electric bicycles , and even electric kick scooters are a simple form of a hybrid, powered by an internal combustion engine or electric motor and
5900-407: The energy stored in the accumulator. A smaller more efficient constant speed engine reduces weight and liberates space for a larger accumulator. Current vehicle bodies are designed around the mechanicals of existing engine/transmission setups. It is restrictive and far from ideal to install petro-hydraulic mechanicals into existing bodies not designed for hydraulic setups. One research project's goal
6000-406: The engine is detached from the drivetrain, serving solely to charge the energy accumulator. The transmission is seamless. Regenerative braking can be used to recover some of the supplied drive energy back into the accumulator. A French company, MDI , has designed and has running models of a petro-air hybrid engine car. The system does not use air motors to drive the vehicle, being directly driven by
6100-407: The filter, and to function well to several hundred degrees Fahrenheit or Celsius. Filters are an important part of hydraulic systems which removes the unwanted particles from fluid. Metal particles are continually produced by mechanical components and need to be removed along with other contaminants. Filters may be positioned in many locations. The filter may be located between the reservoir and
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#17327808405496200-434: The flow from one component to the next. Each component has entry and exit points for the fluid involved (called ports) sized according to how much fluid is expected to pass through it. There are a number of standardized methods in use to attach the hose or tube to the component. Some are intended for ease of use and service, others are better for higher system pressures or control of leakage. The most common method, in general,
6300-422: The following components: For the hydraulic fluid to do work, it must flow to the actuator and/or motors, then return to a reservoir. The fluid is then filtered and re-pumped. The path taken by hydraulic fluid is called a hydraulic circuit of which there are several types. Open-loop: Pump-inlet and motor-return (via the directional valve) are connected to the hydraulic tank. The term loop applies to feedback;
6400-410: The force exerted on C1 is 10 lbf , the force exerted by C2 is 1000 lbf because C2 is a hundred times larger in area ( S = π r ²) as C1. The downside to this is that you have to move C1 a hundred inches to move C2 one inch. The most common use for this is the classical hydraulic jack where a pumping cylinder with a small diameter is connected to the lifting cylinder with a large diameter. If
6500-475: The high costs of the equipment precluded the systems from lighter trucks and cars. In the modern sense, an experiment proved the viability of small petro-hydraulic hybrid road vehicles in 1978. A group of students at Minneapolis, Minnesota's Hennepin Vocational Technical Center, converted a Volkswagen Beetle car to run as a petro-hydraulic hybrid using off-the-shelf components. A car rated at 32 mpg ‑US (7.4 L/100 km; 38 mpg ‑imp )
6600-481: The hose to the fitting. Another disadvantage of hoses is the shorter life of rubber which requires periodic replacement, usually at five to seven year intervals. Tubes and pipes for hydraulic n applications are internally oiled before the system is commissioned. Usually steel piping is painted outside. Where flare and other couplings are used, the paint is removed under the nut, and is a location where corrosion can begin. For this reason, in marine applications most piping
6700-456: The huge multiplication of forces that can be achieved by applying pressures over relatively large areas. One drawback, compared to machines using gears and shafts, is that any transmission of power results in some losses due to resistance of fluid flow through the piping. Joseph Bramah patented the hydraulic press in 1795. While working at Bramah's shop, Henry Maudslay suggested a cup leather packing. Because it produced superior results,
6800-660: The hydraulic press eventually displaced the steam hammer for metal forging. To supply large-scale power that was impractical for individual steam engines, central station hydraulic systems were developed. Hydraulic power was used to operate cranes and other machinery in British ports and elsewhere in Europe. The largest hydraulic system was in London. Hydraulic power was used extensively in Bessemer steel production. Hydraulic power
6900-549: The internal combustion engine, the electric motor and gearbox are coupled by automatically controlled clutches. For electric driving, the clutch between the internal combustion engine is open while the clutch to the gearbox is engaged. While in combustion mode the engine and motor run at the same speed. The first mass-production parallel hybrid sold outside Japan was the 1st generation Honda Insight . The Mercedes-Benz E 300 BlueTEC HYBRID released in 2012 only in European markets
7000-414: The larger diameters the pipe can usually be inspected internally after welding. Black pipe is non-galvanized and suitable for welding . Hydraulic hose is graded by pressure, temperature, and fluid compatibility. Hoses are used when pipes or tubes can not be used, usually to provide flexibility for machine operation or maintenance. The hose is built up with rubber and steel layers. A rubber interior
7100-466: The larger sizes and pressures), welding cones/nipples (with o-ring seal), several types of flare connection and by cut-rings. In larger sizes, hydraulic pipes are used. Direct joining of tubes by welding is not acceptable since the interior cannot be inspected. Hydraulic pipe is used in case standard hydraulic tubes are not available. Generally these are used for low pressure. They can be connected by threaded connections, but usually by welds. Because of
7200-400: The linear force in this case is a rotary force, defined as torque. Both these examples are usually referred to as a hydraulic transmission or hydrostatic transmission involving a certain hydraulic "gear ratio". A hydraulic circuit is a system comprising an interconnected set of discrete components that transport liquid . The purpose of this system may be to control where fluid flows (as in
7300-399: The load and operating conditions. The hydrostatic transmission is generally limited to around 200 kW maximum power, as the total cost gets too high at higher power compared to a hydrodynamic transmission. Large wheel loaders for instance and heavy machines are therefore usually equipped with converter transmissions. Recent technical achievements for the converter transmissions have improved
7400-614: The load. Hence, a pump rated for 5,000 psi is capable of maintaining flow against a load of 5,000 psi. Pumps have a power density about ten times greater than an electric motor (by volume). They are powered by an electric motor or an engine, connected through gears, belts, or a flexible elastomeric coupling to reduce vibration. Common types of hydraulic pumps to hydraulic machinery applications are: Piston pumps are more expensive than gear or vane pumps, but provide longer life operating at higher pressure, with difficult fluids and longer continuous duty cycles. Piston pumps make up one half of
7500-399: The low pressure side. Closed-loop circuits are generally used for hydrostatic transmissions in mobile applications. Advantages: No directional valve and better response, the circuit can work with higher pressure. The pump swivel angle covers both positive and negative flow direction. Disadvantages: The pump cannot be utilized for any other hydraulic function in an easy way and cooling can be
7600-483: The more correct term is open versus closed "circuit". Open center circuits use pumps which supply a continuous flow. The flow is returned to the tank through the control valve's open center; that is, when the control valve is centered, it provides an open return path to the tank and the fluid is not pumped to a high pressure. Otherwise, if the control valve is actuated it routes fluid to and from an actuator and tank. The fluid's pressure will rise to meet any resistance, since
7700-399: The motor housing from rotating effects and losses in the ball bearings can be considerable as motor speeds will reach 4000-5000 rev/min or even more at maximum vehicle speed. The leakage flow as well as the extra flush flow must be supplied by the charge pump. A large charge pump is thus very important if the transmission is designed for high pressures and high motor speeds. High oil temperature
7800-410: The motor must be limited to a reasonable value. Circuit pressure during transport around 200-250 bar is recommended. Closed loop systems in mobile equipment are generally used for the transmission as an alternative to mechanical and hydrodynamic (converter) transmissions. The advantage is a stepless gear ratio (continuously variable speed/torque) and a more flexible control of the gear ratio depending on
7900-425: The need for mechanical gears or levers, either by altering the effective areas in two connected cylinders or the effective displacement (cc/rev) between a pump and motor. In normal cases, hydraulic ratios are combined with a mechanical force or torque ratio for optimum machine designs such as boom movements and track drives for an excavator. Cylinder C1 is one inch in radius, and cylinder C2 is ten inches in radius. If
8000-575: The oldest production hybrids, running on diesel while surfaced and batteries when submerged. Both series and parallel setups were used in World War II-era submarines. Europe The new Autorail à grande capacité (AGC or high-capacity railcar) built by the Canadian company Bombardier for service in France is diesel/electric motors, using 1500 or 25,000 V on different rail systems. It
8100-496: The potential to do 5,000 km. The current record, held by Dutch team Nuon, is 4,716 km, set in 2016 in their car Nuna . The challenge route may change from year to year. In 2022, it ran from Carnival City near Johannesburg to Cape Town over the course of 8 days. The challenge has both local South African teams from both high schools and universities participate, as well as some top-ranking international teams from Japan (Tokai), Belgium ( Innoptus Solar Team previously known as Agoria) and
8200-452: The power input to the pump equals the (max. load pressure + Δ p LS ) x sum of flow. Technically the down-stream mounted compensator in a valve block can physically be mounted "up-stream", but work as a down-stream compensator. System type (3) gives the advantage that activated functions are synchronized independent of pump flow capacity. The flow relation between two or more activated functions remains independent of load pressures, even if
8300-453: The pump has a constant output. If the pressure rises too high, fluid returns to the tank through a pressure relief valve. Multiple control valves may be stacked in series. This type of circuit can use inexpensive, constant displacement pumps. Closed-loop: Motor-return is connected directly to the pump-inlet. To keep up pressure on the low pressure side, the circuits have a charge pump (a small gear pump) that supplies cooled and filtered oil to
8400-407: The pump intake. Blockage of the filter will cause cavitation and possibly failure of the pump. Sometimes the filter is located between the pump and the control valves. This arrangement is more expensive, since the filter housing is pressurized, but eliminates cavitation problems and protects the control valve from pump failures. The third common filter location is just before the return line enters
8500-430: The pump reaches the maximum swivel angle. This feature is important for machines that often run with the pump at maximum swivel angle and with several activated functions that must be synchronized in speed, such as with excavators. With the type (4) system, the functions with up-stream compensators have priority, for example the steering function for a wheel loader. The system type with down-stream compensators usually have
8600-434: The regulator for the variable pump that supplies the oil: Load-sensing systems (LS) generate less power losses as the pump can reduce both flow and pressure to match the load requirements, but require more tuning than the CP system with respect to system stability. The LS system also requires additional logical valves and compensator valves in the directional valves, thus it is technically more complex and more expensive than
8700-697: The reservoir. This location is relatively insensitive to blockage and does not require a pressurized housing, but contaminants that enter the reservoir from external sources are not filtered until passing through the system at least once. Filters are used from 7 micron to 15 micron depends upon the viscosity grade of hydraulic oil. Hydraulic tubes are seamless steel precision pipes, specially manufactured for hydraulics. The tubes have standard sizes for different pressure ranges, with standard diameters up to 100 mm. The tubes are supplied by manufacturers in lengths of 6 m, cleaned, oiled and plugged. The tubes are interconnected by different types of flanges (especially for
8800-628: The rider's muscles. Early prototype motorcycles in the late 19th century used the same principle. The first published prototype of an SHB is by Augustus Kinzel (US Patent 3'884'317) in 1975. In 1994 Bernie Macdonalds conceived the Electrilite SHB with power electronics allowing regenerative braking and pedaling while stationary. In 1995 Thomas Muller designed and built a "Fahrrad mit elektromagnetischem Antrieb" for his 1995 diploma thesis. In 1996 Jürg Blatter and Andreas Fuchs of Berne University of Applied Sciences built an SHB and in 1998 modified
8900-428: The same engine to be hybrids, although to avoid confusion with hybrids as described above and to use correctly the terms, these are perhaps more correctly described as dual mode vehicles: Hydraulic hybrid and pneumatic hybrid vehicles use an engine or regenerative braking (or both) to charge a pressure accumulator to drive the wheels via hydraulic (liquid) or pneumatic (compressed gas) drive units. In most cases
9000-401: The spool left or right. A seal allows 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
9100-539: 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
9200-519: The technology for such electrical infrastructure is largely outdated and, outside some cities, not widely distributed (see Conduit current collection , trams , electric rail , trolleys , third rail ). Updating the required electrical and infrastructure costs could perhaps be funded by toll revenue or by dedicated transportation taxes. In addition to vehicles that use two or more different devices for propulsion , some also consider vehicles that use distinct energy sources or input types (" fuels ") using
9300-491: 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 (25 μm). 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 which push
9400-441: The wheels and reversing to claw-back kinetic braking energy. The hub motors eliminate the need for friction brakes, mechanical transmissions, driveshafts, and U-joints, reducing costs and weight. Hydrostatic drive with no friction brakes is used in industrial vehicles. The aim is 170 mpg in average driving conditions. The energy created by shock absorbers and kinetic braking energy that normally would be wasted assists in charging
9500-434: Was adapted to the new hydraulic powertrain for assessment. PSA Peugeot Citroën exhibited an experimental "Hybrid Air" engine at the 2013 Geneva Motor Show . The vehicle uses nitrogen gas compressed by energy harvested from braking or deceleration to power a hydraulic drive which supplements power from its conventional gasoline engine. The hydraulic and electronic components were supplied by Robert Bosch GmbH . Mileage
9600-483: Was also used for elevators, to operate canal locks and rotating sections of bridges. Some of these systems remained in use well into the twentieth century. Harry Franklin Vickers was called the "Father of Industrial Hydraulics" by ASME . A fundamental feature of hydraulic systems is the ability to apply force or torque multiplication in an easy way, independent of the distance between the input and output, without
9700-460: Was estimated to be about 118 mpg ‑US (2 L/100 km; 142 mpg ‑imp ) on the Euro test cycle if installed in a Citroën C3 type of body. PSA Although the car was ready for production and was proven and feasible delivering the claimed results, Peugeot Citroën were unable to attract a major manufacturer to share the high development costs and are shelving the project until
9800-409: Was returning 75 mpg ‑US (3.1 L/100 km; 90 mpg ‑imp ) with the 60 hp engine replaced by a 16 hp engine. The experimental car reached 70 mph (110 km/h). In the 1990s, a team of engineers working at EPA's National Vehicle and Fuel Emissions Laboratory succeeded in developing a revolutionary type of petro-hydraulic hybrid powertrain that would propel
9900-456: Was tested in Rotterdam, the Netherlands with Railfeeding, a Genesee & Wyoming company. China The First Hybrid Evaluating locomotive was designed by rail research center Matrai in 1999 and built in 2000. It was an EMD G12 locomotive upgraded with batteries, a 200 kW diesel generator, and four AC motors. Japan Japan's first hybrid train with significant energy storage is
10000-479: Was that the power driving motors were not efficient enough at part load. A British company ( Artemis Intelligent Power ) made a breakthrough introducing an electronically controlled hydraulic motor/pump, the Digital Displacement® motor/pump. The pump is highly efficient at all speed ranges and loads, giving feasibility to small applications of petro-hydraulic hybrids. The company converted a BMW car as
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