Misplaced Pages

#703296

69-417: HSD technology produces a full hybrid vehicle which allows the car to run on the electric motor only, as opposed to most other brand hybrids which cannot and are considered mild hybrids . The HSD also combines an electric drive and a planetary gearset which performs similarly to a continuously variable transmission . The Synergy Drive is a drive-by-wire system with no direct mechanical connection between

138-444: A clutch , or automatic, with a torque converter , but both allow the engine and the wheels to rotate at different speeds. The driver can adjust the speed and torque delivered by the engine with the accelerator and the transmission mechanically transmits nearly all of the available power to the wheels which rotate at a different rate than the engine, by a factor equal to the gear ratio for the currently selected gear. However, there are

207-419: A continuously variable transmission (CVT), except that the torque/speed conversion uses an electric motor rather than a direct mechanical gear train connection. An HSD car cannot operate without the computer, power electronics, battery pack, and motor-generators, though in principle it could operate while missing the internal combustion engine. (See: Plug-in hybrid ) In practice, HSD equipped cars can be driven

276-487: A one-way clutch on the planetary gear carrier of the second planetary gearset. By selectively engaging these, the transmission can simulate ten different gear ratios. The fifth generation Hybrid Synergy Drive transaxle is similar to the prior generation, with detail improvements making the electric motors lighter, more compact, and more powerful. The following is a list of vehicles with Hybrid Synergy Drive and related technologies (Toyota Hybrid System): As of autumn 2005,

345-406: A ravigneaux-type gear with four shafts, two of which can be held still alternatively by a brake/clutch. The GS 450h and LS 600h systems utilized rear-wheel drive and all-wheel drive drivetrains, respectively, and were designed to be more powerful than non-hybrid versions of the same model lines, while providing comparable engine class efficiency. A simplified version was released in 2012 with

414-550: A Paice patent, Toyota invented, designed and developed the Prius and Toyota’s hybrid technology independent of any inventions of Dr. Severinsky and Paice as part of Toyota’s long history of innovation". Paice earlier entered into an agreement with Ford for the license of Paice's patent. Full hybrid Too Many Requests If you report this error to the Wikimedia System Administrators, please include

483-475: A computer that's solely dedicated to keeping the battery at the optimum temperature and optimum charge level. Like the second generation Prius, the third generation Prius battery pack is made up of the same type of 1.2 volt cells. It has 28 modules of 6 cells for a total nominal voltage of only 201.6 volts. A boost converter is used to produce 500 volt DC supply voltage for the inverters for MG1 and MG2. The car's electronics only allow 40% of total rated capacity of

552-641: A continuous, gradual improvement in the specific capacity of the traction battery. The original Prius used shrink-wrapped 1.2 volt D cells, and all subsequent THS/HSD vehicles have used custom 7.2 V battery modules mounted in a carrier. In 2001, a modified version of the Generation 1 THS transaxle was released in the Japanese domestic market as the P210 transaxle, fitted to the Estima minivan. The P210 couples

621-414: A continuously variable transmission allows the driver (or the automobile computer) to effectively select the optimal gear ratio required for any desired speed or power. The transmission is not limited to a fixed set of gears. This lack of constraint frees the engine to operate at its optimal brake-specific fuel consumption . An HSD vehicle will typically run the engine at its optimal efficiency whenever power

690-466: A controllable torque transfer unit ( US patent 5343970 , Severinsky; Alex J., "Hybrid electric vehicle", issued 1994-09-06   ) and has additional patents related to hybrid vehicles. In 2010 Toyota agreed to license Paice's patents; terms of the settlement were not disclosed. In the settlement "The parties agree that, although certain Toyota vehicles have been found to be equivalent to

759-669: A court in Düsseldorf had ruled that the Toyota Prius driveline and the Lexus RX 400h driveline do not breach the Antonov hybrid CVT patent. Ford Motor Company independently developed a system with key technologies similar to Toyota's HSD technology in 2004. As a result, Ford licensed 21 patents from Toyota in exchange for patents relating to emissions technology. Paice LLC received a patent for an improved hybrid vehicle with

SECTION 10

#1732790348704

828-665: A levy on each vehicle sold, which could make the hybrid SUV less competitive. Toyota fought back by seeking to officially invalidate Antonov's relevant patents. The court motion in Microsoft Word document format can be read here. On 1 September 2006 Antonov announced that the Federal Patent Court in Munich has not upheld the validity of the German part of Antonov's patent (EP0414782) against Toyota. A few days later,

897-530: A limited number of "gears" or gear ratios that the driver can choose from, typically four to six. This limited gear-ratio set forces the engine crankshaft to rotate at speeds where the ICE is less efficient, i.e., where a liter of fuel produces fewer joules. Optimal engine speed-torque requirements for different vehicle driving and acceleration conditions can be gauged by limiting either tachometer RPM rate or engine noise in comparison with actual speed. When an engine

966-491: A lot for different engine designs, and compression ratio and power rating. Engines of different classes like diesels and gasoline engines will have very different BSFC numbers, ranging from less than 200 g/(kW⋅h) (diesel at low speed and high torque) to more than 1,000 g/(kW⋅h) (turboprop at low power level). The following table takes values as an example for the specific fuel consumption of several types of engines. For specific engines values can and often do differ from

1035-414: A mile or two without gasoline, as an emergency measure to reach a gas station . An HSD transaxle contains a planetary gear set that adjusts and blends the amount of torque from the engine and motor(s) as it's needed by the front wheels. It is a sophisticated and complicated combination of gearing, electrical motor-generators, and computer-controlled electronic controls. One of the motor-generators, MG2,

1104-412: A normal geared transmission with an electromechanical system. An internal combustion engine (ICE) delivers power most efficiently over a small speed range, but the wheels need to be driven over the vehicle's full speed range. In a conventional automobile the geared transmission delivers different discrete engine speed-torque power requirements to the wheels. Geared transmissions may be manual, with

1173-478: A reciprocating engine achieves maximum efficiency when the intake air is unthrottled and the engine is running near its peak torque. The efficiency often reported for a particular engine, however, is not its maximum efficiency but a fuel economy cycle statistical average. For example, the cycle average value of BSFC for a gasoline engine is 322 g/(kW⋅h), translating to an efficiency of 25% (1/(322 × 0.0122225) = 0.2540). Actual efficiency can be lower or higher than

1242-561: A reduction in size and combined weight. The traction motor itself is considerably more compact and gains a better power-to-weight ratio . Notably there is a 20 percent reduction in mechanical losses due to friction compared to the previous model. The 2012– Prius c retains the P510 transaxle. The P610 transaxle employs helical gears rather than the straight-cut spur gears employed in the earlier transaxles, and which run more smoothly and quietly, while also accommodating higher mechanical loads. With

1311-412: A storage battery through an inverter. Although MG1 typically operates as a generator (alternator), it also serves as the starter motor for the internal combustion engine. MG2 usually acts as a motor, either by itself at low speeds or to assist the internal combustion engine, but MG2 also can act as a generator, for instance, during deceleration for regenerative braking . Schematically, MG1 is connected to

1380-447: A test stand and a load applied to the running engine. The resulting units of BSFC are grams per joule (g/J) Commonly BSFC is expressed in units of grams per kilowatt-hour (g/(kW⋅h)). The conversion factor is as follows: The conversion between metric and imperial units is: To calculate the actual efficiency of an engine requires the energy density of the fuel being used. Different fuels have different energy densities defined by

1449-409: Is connected to the output shaft, and thus couples torque into or out of the drive shafts; feeding electricity into MG2 adds torque at the wheels. The engine end of the drive shaft has a second differential ; one leg of this differential is attached to the internal combustion engine and the other leg is attached to a second motor-generator, MG1. The differential relates the rotation speed of the wheels to

SECTION 20

#1732790348704

1518-480: Is needed to charge batteries or accelerate the car, shutting down the engine entirely when less power is required. Like a CVT , an HSD transmission continuously adjusts the effective gear ratio between the engine and the wheels to maintain the engine speed while the wheels increase their rotational speed during acceleration. This is why Toyota describes HSD-equipped vehicles as having an e-CVT ( electronic continuously variable transmission ) when required to classify

1587-561: Is not uncommon, especially for extended drives at modest speeds (a longer drive allows the engine to warm up fully). This is approximately twice the fuel efficiency of a similarly equipped four-door sedan with a conventional power train. Not all of the extra efficiency of the Prius is due to the HSD system: the Atkinson cycle engine itself was also designed specifically to minimize engine drag via an offset crankshaft to minimize piston drag during

1656-433: Is outfitted with 4.4 kWh lithium-ion batteries co-developed with Panasonic that weighs 80 kg (180 lb) compared with the nickel-metal hydride battery of the third generation Prius , which has a capacity of only 1.3 kWh, and weighs 42 kg (93 lb). The larger battery pack enables all-electric operation at higher speeds and longer distances than the conventional Prius hybrid. The following table details

1725-467: Is required to operate efficiently across a broad RPM range, due to its coupling to a geared transmission, manufacturers are limited in their options for improving engine efficiency , reliability, or lifespan, as well as reducing the size or weight of the engine. This is why the engine for an engine-generator is often much smaller, more efficient, more reliable, and longer life than one designed for an automobile or other variable speed application. However,

1794-599: The Ford Escape Hybrid . Toyota CEO Katsuaki Watanabe said in a February 16, 2007 interview that Toyota was "aiming at reducing, by half, both the size and cost of the third-generation HSD system". The new system will feature lithium-ion batteries in later years. Lithium-ion batteries have a higher energy capacity-to-weight ratio compared to NiMH , but operate at higher temperatures, and are subject to thermal instability if not properly manufactured and controlled, raising safety concerns. In 2005, vehicles such as

1863-609: The fourteenth generation Crown (S210) ; the L210 transmission omits the two clutches but retains the second planetary gearset (MSRD) applied to the output of MG2, in common with other Generation 3 transaxles. However, compared to the G3 transaxles, instead of coupling the two ring gears, the L210 couples the PSD ring gear to the MSRD planetary gear carrier, and grounds the ring gear of the MSRD instead of

1932-565: The power stroke , and a unique intake system to prevent drag caused by manifold vacuum ("pumping losses") versus the normal Otto cycle in most engines. Furthermore, the Atkinson cycle recovers more energy per cycle than the Otto because of its longer power stroke. The downside of the Atkinson cycle is much reduced torque, particularly at low speed; but the HSD has enormous low-speed torque available from MG2. The Highlander Hybrid (also sold as

2001-701: The Antonov Automotive Technology BV Plc company has sued Toyota , the Lexus brand mother company, over alleged patent infringement relating to key components in the RX 400h's drivetrain and the Toyota Prius hybrid compact car. The case has been pending in secret since April 2005, but settlement negotiations did not bring a mutually acceptable result. Antonov eventually took legal recourse in the German court system, where decisions are usually made relatively swiftly. The patent holder seeks to impose

2070-517: The Estima was released at the same time; the Q410 rear drive unit uses an electric traction motor with no mechanical coupling to the front transaxle. THS was followed by THS-II in the 2004 Prius. Starting with THS-II, Toyota also began referring to the system as Hybrid Synergy Drive (HSD). Compared to THS, THS-II offered reduced consumption and better performance with increased power and torque. THS-II uses

2139-483: The Fourth Generation HSD, Toyota is also offering a four-wheel drive option, dubbed "E-Four", similar to the 2005 RX400h and Highlander Hybrid, in which an electric traction motor is added to the rear, but is not mechanically coupled to the internal combustion engine or front inverter. In fact, the "E-Four" system has its own rear inverter, although this inverter draws power from the same hybrid battery as

Hybrid Synergy Drive - Misplaced Pages Continue

2208-539: The Generation 3 HSD as it provides for a smaller, yet more powerful MG2. However, a secondary benefit is the MG1 will not be driven into overspeed as frequently, and which would otherwise mandate employing the ICE to mitigate this overspeed; this strategy improves HSD performance as well as saving fuel and wear-and-tear on the ICE. The HSD system has two principal battery packs, the High Voltage (HV) battery, also known as

2277-447: The HSD powered car significant efficiency advantages—particularly in city driving. The HSD operates in distinct phases depending on speed and demanded torque. Here are a few of them: The Toyota Prius has modest acceleration but has extremely high efficiency for a midsized four-door sedan: usually significantly better than 40 mpg (US) (5.9 L/100 km) is typical of brief city jaunts; 55 mpg (4.3 L/100 km)

2346-625: The HV battery capacity for several Lexus and Toyota vehicles. The HSD drive works by shunting electrical power between the two motor generators, running off the battery pack, to even out the load on the internal combustion engine. Since a power boost from the electrical motors is available for periods of rapid acceleration, the ICE can be downsized to match only the average load on the car, rather than sized by peak power demands for rapid acceleration. The smaller internal combustion engine can be designed to run more efficiently. Furthermore, during normal operation

2415-538: The Highlander Hybrid rates between 27 and 31 mpg (8.7–7.6 L/100 km). A conventional Highlander is rated by the EPA with 19 city, 25 highway mpg (12.4 and 9.4 L/100 km respectively). The HSD mileage boost depends on using the gasoline engine as efficiently as possible, which requires: Most HSD systems have batteries that are sized for maximal boost during a single acceleration from zero to

2484-762: The ICE/MG1 and the MG2 have separate reduction paths, and are combined in a "compound" gear which is connected to the final reduction gear train and differential; it was introduced on all-wheel drive and rear-wheel drive Lexus models. By May 2007 Toyota had sold one million hybrids worldwide; two million by the end of August 2009; and passed the 5 million mark in March 2013. As of September 2014, more than 7 million Lexus and Toyota hybrids had been sold worldwide. The United States accounted for 38% of TMC global hybrid sales as of March 2013. Toyota's HSD system replaces

2553-472: The Kluger in some countries) offers better acceleration performance compared to its non-hybrid version. The hybrid version goes from 0–60 mph in 7.2 seconds, trimming almost a second off the conventional version's time. Net power is 268 hp (200 kW) compared to the conventional 215 hp (160 kW). Top speed for all Highlanders is limited to 112 mph (180 km/h). Typical fuel economy for

2622-575: The Lexus Hybrid Drive name, was fitted to the Lexus GS 450h / LS 600h sedans as the L110 transmission. Previous versions of HSD/THS were fitted to transaxles used with front-wheel drive platforms; Lexus Hybrid Drive applied the two-motor HSD concept to a longitudinal transmission for rear-wheel drive vehicles. This system uses two clutches (or brakes) to switch the second motor's gear ratio to

2691-402: The Lexus RX 400h and Toyota Highlander Hybrid added four-wheel drive operation by adding a third electric motor ("MGR") on the rear axle. In this system, the rear axle is purely electrically powered, and there is no mechanical link between the engine and the rear wheels. This also permits regenerative braking on the rear wheels. In 2006 and 2007, a further development of the HSD drivetrain, under

2760-488: The Motor Speed Reduction Device (MSRD); it is compounded with the first planetary gearset (PSD) by coupling the two ring gears together. The coupled ring gears are still used to drive the front wheels of the vehicle. The traction motor (MG2) uses the MSRD as a reduction gear, making it possible to increase the power density of the motor. Ford has also developed a similar hybrid system, introduced in

2829-492: The Toyota brand ( Lexus ; the HSD-derived systems used in Lexus vehicles have been termed Lexus Hybrid Drive ), was implemented in the 2006 Camry and Highlander, and would eventually be implemented in the 2010 "third generation" Prius , and the 2012 Prius c . The Toyota Hybrid System is designed for increased power and efficiency, and also improved "scalability" (adaptability to larger as well as smaller vehicles), wherein

Hybrid Synergy Drive - Misplaced Pages Continue

2898-512: The battery is exhausted and the car can achieve only 55–60 mph on the same slope. (until the battery is recharged by driving under less demanding circumstances) The design of the Toyota Hybrid System ;/ Hybrid Synergy Drive has now had five generations since the original 1997 Japanese-market Toyota Prius. The power train has the same basic features, but there have been a number of significant refinements. The system

2967-678: The battery pack (6.5 ampere-hour) to be used in order to prolong the battery life. As a result, the SoC is allowed to vary only between 40% and 80% of the rated full charge. The battery used in the Highlander Hybrid and the Lexus RX 400h was packaged in a different metal battery casing with 240 cells that deliver high voltage of 288 volts. A button labelled "EV" maintains electric vehicle mode after being powered on and under most low-load conditions at less than 25 mph (40 km/h) if

3036-437: The car's internal combustion engine and run accessories when the engine is not running. The alternator is used to recharge the battery and run the accessories when the engine is running. The HSD system replaces the geared transmission, alternator, and starter motor with: Through the power splitter, a series-parallel full hybrid's HSD system thus allows for the following intelligent power flows: The mechanical gearing design of

3105-424: The central sun gear (S), the internal combustion engine is connected to the planetary gear carrier (P) and not to any individual gear, and MG2 is connected to the ring gear (R). The wheels are connected to the ring gear through appropriate reduction gearing and a differential, not illustrated in the diagram. The Toyota Hybrid System uses a high-voltage battery pack, ranging between 276 and 288 V. There has been

3174-420: The conventional engine-driven type. This removes the need to continuously run the engine when cabin cooling is required. Two positive temperature coefficient heaters are fitted in the heater core to supplement the heat provided by the engine. The updated version of HSD first delivered in the model year 2006 RX 400h is similar to THS/THS-II, with the addition of a second planetary gearset, which Toyota calls

3243-422: The details below. Request from 172.68.168.236 via cp1112 cp1112, Varnish XID 968282317 Upstream caches: cp1112 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 10:39:09 GMT Brake-specific fuel consumption Brake-specific fuel consumption ( BSFC ) is a measure of the fuel efficiency of any prime mover that burns fuel and produces rotational, or shaft power. It is typically used for comparing

3312-400: The drive shafts, for feedback to the control computer. In Generation 1 and Generation 2 HSDs, MG2 is directly connected to the ring gear, that is, a 1:1 ratio, and which offers no torque multiplication, whereas in Generation 3 HSDs, MG2 is connected to the ring gear through a 2.5:1 planetary gear set, and which, consequently, offers a 2.5:1 torque multiplication, this being a primary benefit of

3381-495: The efficiency of internal combustion engines with a shaft output. It is the rate of fuel consumption divided by the power produced. In traditional units, it measures fuel consumption in pounds per hour divided by the brake horsepower , lb/(hp⋅h); in SI units , this corresponds to the inverse of the units of specific energy , kg/J = s /m . It may also be thought of as power- specific fuel consumption, for this reason. BSFC allows

3450-417: The engine and the engine controls: both the gas pedal/accelerator and the gearshift lever in an HSD car merely send electrical signals to a control computer . HSD is a refinement of the original Toyota Hybrid System ( THS ) used in the 1997 to 2003 Toyota Prius. The second generation system first appeared on the redesigned Prius in 2004. The name was changed in anticipation of its use in vehicles outside

3519-512: The engine can be operated at or near its ideal speed and torque level for power, economy, or emissions, with the battery pack absorbing or supplying power as appropriate to balance the demand placed by the driver . During traffic stops the internal combustion engine can even be turned off for even more economy. The combination of efficient car design, regenerative braking, turning the engine off for traffic stops, significant electrical energy storage and efficient internal combustion engine design give

SECTION 50

#1732790348704

3588-437: The engine’s average due to varying operating conditions. In the case of a production gasoline engine, the most efficient BSFC is approximately 225 g/(kW⋅h), which is equivalent to a thermodynamic efficiency of 36%. An iso-BSFC map (fuel island plot) of a diesel engine is shown. The sweet spot at 206 BSFC has 40.6% efficiency. The x-axis is rpm; y-axis is BMEP in bar (bmep is proportional to torque ) BSFC numbers change

3657-586: The front inverter. "E-Four" began being offered in Prius models in the United States in the 2019 model year. "E-Four" is an integral part of the RAV4 Hybrid models offered in the United States, and all such RAV4 Hybrids are "E-Four" only. The L310 transmission for rear-wheel drive applications succeeded the prior L110 transmission in premium vehicles. Compared to the L110 and L210, the L310 couples MG2 to

3726-466: The fuel efficiency of different engines to be directly compared. The term "brake" here as in " brake horsepower " refers to a historical method of measuring torque (see Prony brake ). The brake-specific fuel consumption is given by, where: The above values of r , ω {\displaystyle \omega } , and τ {\displaystyle \tau } may be readily measured by instrumentation with an engine mounted in

3795-476: The fuel's heating value. The lower heating value (LHV) is used for internal-combustion-engine-efficiency calculations because the heat at temperatures below 150 °C (300 °F) cannot be put to use. Some examples of lower heating values for vehicle fuels are: Thus a diesel engine's efficiency = 1/(BSFC × 0.0119531) and a gasoline engine's efficiency = 1/(BSFC × 0.0122225) Any engine will have different BSFC values at different speeds and loads. For example,

3864-487: The internal combustion engine with the sun gear and couples the starter/generator (MG1) with the planetary gear carrier, which is the opposite of the G1 THS scheme. In addition, the single-motor G1 THS omits the traction motor (MG2) and uses a belt-drive continuously variable transmission which can be selectively coupled via rotating clutches to either the planetary gear carrier or the ring gear. An all-wheel drive option for

3933-610: The physical size of the traction motor (MG2) in THS-II remains approximately the same, but the maximum output has increased from 33 to 50 kW (44 to 67 hp) and the maximum torque has increased from 350 to 400 N⋅m (260 to 300 lbf⋅ft). The stator windings are connected in series, which requires a higher potential. Although not part of the THS/HSD as such, starting with the 2004 Prius, all THS/HSD vehicles have been fitted with an electric air-conditioning compressor, instead of

4002-726: The planetary gear carrier. On October 13, 2015, Toyota announced details of the Fourth Generation Hybrid Synergy Drive which was introduced for the 2016 model year. The overall design returns to a single planetary gearset similar to THS/THS-II; parallel reduction gears on the Fourth Generation transaxles replace the Motor Speed Reduction Device, which is a second planetary gear set found in the Third Generation transaxles. The transaxle and traction motor have been redesigned, delivering

4071-399: The ring gear of the PSD. In addition L310 adds a third planetary gearset, compounded with the second (MSRD) by coupling the planetary gear carrier of the second planetary gearset with the ring gear of the third planetary gearset, and by coupling the ring gear of the second with the planetary gear carrier of the third. In addition, several rotating clutches and brakes have been added, including

4140-400: The rotation speeds of the engine and MG1, with MG1 used to absorb the difference between wheel and engine speed. The differential is an epicyclic gear set (also called a "power split device"); that and the two motor-generators are all contained in a single transaxle housing that is bolted to the engine . Special couplings and sensors monitor rotation speed of each shaft and the total torque on

4209-411: The same design as THS, combining traction power from an internal combustion engine and an electric motor via a planetary gearset (power split device) which can divert some power to an electrical generator. Electrically, HSD/THS-II adds a DC to DC converter boosting the potential of the battery to 500 V or more. This allows smaller battery packs to be used, and more powerful motors. Compared to THS,

SECTION 60

#1732790348704

4278-410: The second generation Prius consisted of 28 Panasonic prismatic nickel metal hydride modules, each containing six 1.2 volt cells, connected in series to produce a nominal voltage of 201.6 volts. The discharge power capability of the second gen Prius pack is about 20 kW at 50% state of charge (SoC). The power capability increases with higher temperatures and decreases at lower temperatures. The Prius has

4347-405: The system allows the mechanical power from the ICE to be split three ways: extra torque at the wheels (under constant rotation speed), extra rotation speed at the wheels (under constant torque), and power for an electric generator. A computer running appropriate programs controls the systems and directs the power flow from the different engine + motor sources. This power split achieves the benefits of

4416-439: The top speed of the vehicle; if there is more demand, the battery can be completely exhausted, so that this extra torque boost is not available. Then the system reverts to just the power available from the engine. This results in a large decline in performance under certain conditions: an early-model Prius can achieve over 90 mph (140 km/h) on a 6 degree upward slope, but after about 2,000 feet (610 m) of altitude climb

4485-502: The traction battery has enough charge. This permits all-electric driving with no fuel consumption for up to 1 mi (1.6 km). However, the HSD software switches to EV mode automatically whenever it can. Only the Toyota Prius Plug-in Hybrid has a longer driving all-electric range in blended operation electric-gasoline of 11 mi (18 km) ( EPA rating) until the battery is depleted. The Prius PHEV

4554-535: The traction battery, and a 12 volt lead-acid battery known as the Low Voltage (LV) battery, which functions as an auxiliary battery. The LV battery supplies power to the electronics and accessories when the hybrid system is turned off and the high-voltage battery main relay is off. The traction battery is a sealed nickel-metal hydride (NiMH) battery pack. The battery pack of the first generation Toyota Prius consisted of 228 cells packaged in 38 modules, while

4623-408: The transmission type for standards specification lists or regulatory purposes. In a conventional car design the separately-excited alternator with integral rectifier (DC generator) and starter (DC motor) are considered accessories that are attached to the internal combustion engine (ICE) which normally drives a transmission to power the wheels propelling the vehicle. A battery is used only to start

4692-403: The wheels between a ratio of 3.9 and 1.9, for low and high speed driving regimes respectively. This decreases the power flowing from MG1 to MG2 (or vice versa) during higher speeds. The electrical path is only about 70% efficient, thus decreasing its power flow while increasing the overall performance of the transmission. The second planetary gearset is extended with a second carrier and sun gear to

4761-497: Was called the Toyota Hybrid System (THS) when it was introduced with the Prius in 1997. The hybrid transaxle , designated P110, includes two electric motors (MG1 and MG2) and a planetary gearset , which Toyota calls the "Power Split Device" (PSD); mechanical power from the internal combustion engine (E) can be directed either to the wheels or to MG1, acting as a generator. Electrical power flows between MG1, MG2, and

#703296