DE102008019418A1 - Eight-speed transmission for powertrain of vehicle e.g. passenger vehicle, hybrid vehicle, has five clutches engaged in combinations of two to established at least eight forward speed ratios and at least one reverse speed ratio - Google Patents

Abstract

The transmission includes four planetary gear sets which interlock an input shaft to an output shaft and each having components e.g. sun gear, planet gears, and carrier. Five clutches selectively connect components of one planetary gear set to the components of the another planetary gear set, or to transmission case, and are being engaged in combinations of two to establish at least eight forward speed ratios and at least one reverse speed ratio between the input and output shafts. Five interconnecting members continuously couple components of one planetary gear set to corresponding component of another planetary gear set.

Description

Cross reference to related Registrations

These Registration claims the priority of the provisional U.S. Patent Application No. 60 / 912,964 filed April 20, 2007 and the disclosure of which is fully incorporated herein by reference is included

TECHNICAL AREA

The The present invention relates to a power transmission with four planetary gear sets, through five torque transmitting devices be controlled to at least eight forward gears and to provide at least one reverse gear.

BACKGROUND OF THE INVENTION

car include a powertrain consisting of a machine, a multi-speed transmission and a differential or final drive exists. The multi-speed transmission increases the overall operating range of the vehicle by adding allows the machine to rotate its torque range several times can go through. The number of forward gears, available in the transmission determines the frequency with which the torque range of the machine is repeated can be. Early automatic transmissions had two speed ranges on. This greatly limited the entire speed range of the vehicle and therefore required a relatively large machine, the one could produce wide speed and torque range. This resulted that the machine while driving at a specific Fuel consumption point worked, which is not the point with the highest economic efficiency was. Therefore were switched by hand Transmission (countershaft transmission) most popular.

With the advent of three- and four-speed automatic transmissions took the Popularity of the automatic switching (planetary) gearbox at to the drivers too. These transmissions improved the performance and the fuel economy of the vehicle. The raised Number of gears reduces the step size between gear ratios and improved Therefore, the shift quality of the transmission, by changing the gear for the operator at normal vehicle acceleration in the Essentially imperceptible.

Six-speed transmission offer several advantages over four- and five-speed transmissions, the improved vehicle acceleration and improved Include fuel economy. While Many truck power shift transmission with six or more forward gears Passenger cars will apply because of the size and complexity this gear still with three- and four-speed automatic transmissions and relative produced only a few five- or six-speed devices.

Seven-, Eight- and nine-speed transmissions offer further improvements in the Acceleration and fuel economy Six-speed transmissions. As with the six-speed transmissions discussed above however, is the development of seven-, eight- and nine-speed transmissions because of the complexity, size and cost prevented.

SUMMARY OF THE INVENTION

The The present invention provides an improved transmission with four planetary gear sets that are controlled to at least eight forward gears and to provide at least one reverse gear.

The Family of transmissions of the present invention has four planetary gear sets each of which has a first, second and third element, the elements being a sun gear, a ring gear or a planet carrier assembly in any order.

at the reference to the first, second, third and fourth gear set in this specification and in the claims these sentences in the drawings in any order counted from "first" to "fourth" (i.e., from the left to the right, from right to left, etc.). In addition, you can the first, second or third element of each gear set in the Drawings for each gear set in any order be counted with "first" to "third" (ie from above down, from bottom to top, etc.).

Everyone Carrier can either be a single planet carrier (single) or a double planet carrier (composed) be. Embodiments with long planet gears are also possible.

One first connecting element connects the second element of the first Planetary gear set constantly with the third element of the second Planetary gear set.

One second connecting element connects the second element of the second Planetary gear set constantly with the first element of the third Planetary gear set.

One third connecting element connects the third element of the third Planetary gear set constantly with the third element of the fourth Planetary gear set.

A fourth connecting element connects the first element of the first planetary gear set constantly with the first element of the fourth planetary gear set.

One fifth connecting element connects the third element of the first planetary gear set constantly with the second element of the third planetary gear set.

The Drive element is constantly with the first element of the connected to the first planetary gear set. The output element is permanent connected to the second element of the fourth planetary gear set.

A first torque transmitting device, such as a brake, selectively connects the third element of the first planetary gear set with a fixed element (gearbox / gear box).

A second torque transmitting device, such as a brake, selectively connects the first element of the second planetary gear set with a fixed element (gearbox / gear box).

A third torque transmitting device, such as a brake, selectively connects the second element of the second planetary gear set with a fixed element (gearbox / gear box).

A fourth torque transmitting device, such as a clutch, selectively connects the first element of the first planetary gear set with the second element of the first planetary gear set.

A fifth torque transmitting device, such as a clutch connecting the second element of the first planetary gear set selectively with the second element of the fourth planetary gear set.

The five torque transmitting devices are in combinations of two selectively engageable, at least eight forward gears and at least one reverse gear to obtain.

A Variety of speed ratios and ratio spreads can by properly choosing the teeth ratios the planetary gear sets are realized.

The The above features and other features and advantages of the present invention The invention will be apparent from the following detailed description of Best embodiments of the invention in combination become more apparent with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

1a is a schematic representation of a powertrain, which includes a planetary gear, according to the present invention;

1b is a truth table and a graph showing some of the operating characteristics of the 1a illustrate the drive train shown; and

1c is a schematic representation of the powertrain of 1a shown in lever diagram form.

DESCRIPTION OF THE PREFERRED Embodiment

Referring to the drawings, in FIG 1a a powertrain 10 with a conventional engine and torque converter 12 , a planetary gear 14 and a conventional axle drive mechanism 16 shown. The machine 12 can be powered using various types of fuel to improve the efficiency and fuel economy of a particular application. Such fuels may include, for example, gasoline; Diesel; ethanol; Include dimethyl ether, etc.

The planetary gear 14 includes a drive element 17 that constantly with the machine 12 is connected, a planetary gear arrangement 18 and an output element 19 that is constantly working with the final drive mechanism 16 connected is. The planetary gear arrangement 18 includes four planetary gear sets 20 . 30 . 40 and 50 ,

The planetary gear set 20 includes a sun wheel 22 , a ring gear 24 and a planet carrier arrangement 26 , The planet carrier arrangement 26 includes several planet wheels 27 . 28 rotatable on a support 29 are mounted. The planet wheels 27 are combing with the sun wheel 22 arranged, and the planetary gears 28 are combing with both the ring gear 24 as well as the respective planetary gear 27 arranged.

The planetary gear set 30 includes a sun wheel 32 , a ring gear 34 and a planet carrier arrangement 36 , The planet carrier arrangement 36 includes several planet wheels 37 . 38 rotatable on a support 39 are mounted. The planet wheels 38 are combing with the ring gear 34 arranged, and the planetary gears 37 are combing with both the sun gear 32 as well as the respective planetary gear 38 arranged.

The planetary gear set 40 includes a sun wheel 42 , a ring gear 44 and a planet carrier array voltage 46 , The planet carrier arrangement 46 includes several planet wheels 47 . 48 rotatable on a support 49 are mounted. The planet wheels 47 are combing with the sun wheel 42 arranged, and the planetary gears 48 are combing with both the ring gear 44 as well as the respective planetary gear 47 arranged.

The planetary gear set 50 includes a sun wheel 52 , a ring gear 54 and a planet carrier arrangement 56 , The planet carrier arrangement 56 includes several planet wheels 57 rotatable on a support 59 mounted and in mating relationship with both the ring gear 54 as well as the sun wheel 52 are arranged.

The planetary gear assembly also includes five torque transmitting devices 80 . 82 . 84 . 85 and 86 , The torque transmission devices 80 . 82 and 84 are a fixed-type torque-transmitting device, commonly called reaction clutches or brakes. The torque transmission devices 85 and 86 are torque-transmitting devices of the rotating type, which are commonly called clutches.

The drive element 17 is constantly with the sun gear 22 of the planetary gear set 20 connected. The output element 19 is constantly with the planet carrier arrangement 56 of the planetary gear set 50 connected.

A first connection element 70 connects the planet carrier arrangement 26 of the planetary gear set 20 constantly with the ring gear 34 of the planetary gear set 30 , A second connecting element 72 connects the planet carrier arrangement 36 of the planetary gear set 30 constantly with the sun wheel 42 of the planetary gear set 40 , A third connecting element 74 connects the ring gear 44 of the planetary gear set 40 constantly with the ring gear 54 of the planetary gear set 50 , A fourth connection element 76 connects the sun wheel 22 of the planetary gear set 20 constantly with the sun wheel 52 of the planetary gear set 50 , A fifth connecting element 78 connects the ring gear 24 of the planetary gear set 20 constantly with the planet carrier arrangement 46 of the planetary gear set 40 ,

A first torque transmitting device, such as a brake 80 , connects the ring gear 24 of the planetary gear set 20 and the planet carrier arrangement 46 of the planetary gear set 40 over the connecting element 70 selectively with the gearbox 60 , A second torque transmitting device, such as a brake 82 , connects the sun gear 32 of the planetary gear set 30 selectively with the gearbox 60 , A third torque transmitting device, such as a brake 84 , connects the planet carrier arrangement 36 of the planetary gear set 30 selectively with the gearbox 60 , A fourth torque transmitting device, such as a clutch 85 , connects the sun gear 22 of the planetary gear set 20 selectively with the planet carrier arrangement 26 of the planetary gear set 20 , A fifth torque transmitting device, such as a clutch 86 , connects the planet carrier arrangement 26 of the planetary gear set 20 selectively with the planet carrier arrangement 56 of the planetary gear set 50 ,

As it is in 1b and particularly in the truth table disclosed therein, the torque transmitting devices are selectively engaged in combinations of two to provide at least eight forward speeds and at least one reverse speed, all with single transition sequential shifting, and two overdrive ratios.

As stated above, the engagement schedule for the torque transfer devices is in the truth table of FIG 1b shown. The graph of 1b describes the gear ratios and ratio steps achieved in the transmission described above. For example, the step ratio between the first and second forward speeds is 1.59, while the step ratio between the reverse speed and the first forward speed is -0.60.

With reference to 1c is the embodiment of in 1a shown drive train 10 illustrated in a lever diagram format. A lever diagram is a schematic representation of the components of a mechanical device, such as an automatic transmission. Each individual lever represents a planetary gear set, wherein the three basic mechanical components of the planetary gear set are each represented by a node. Therefore, a single lever includes three nodes: one for the sun gear, one for the planet carrier, and one for the ring gear. The relative length between the nodes of each lever can be used to represent each of the ring gear / sun gear ratio of the respective gear set. These levers are in turn used to change the gear ratios of the transmission in order to achieve suitable ratios and suitable ratio progression. Mechanical couplings or connections between the nodes of the various planetary gear sets are illustrated by thin horizontal lines, and torque transmitting devices such as clutches and brakes are shown as interdigitated fingers. If the device is a brake, a set of fingers is grounded. A further explanation of the format, purpose and use of lever diagrams is given in the document SAE Paper 810102, "The Lever Analogy: A New Tool in Transmission Analysis", 1981, authored by Genford, Howard and Leising, Maurice whose disclosure content is hereby fully incorporated by reference.

The powertrain 10 includes a drive element 17 that constantly with the machine 12 is connected, an output element 19 that constantly with the final drive 16 connected, a first planetary gear set 20A comprising three nodes: a first node 22A , a second node 26A and a third node 24A ; a second planetary gear set 30A comprising three nodes: a first node 32A , a second node 36A and a third node 34A ; a third planetary gear set 40A comprising three nodes: a first node 42A , a second node 46A and a third node 44A ; and a fourth planetary gear set 50A comprising three nodes: a first node 52A , a second node 56A and a third node 54A ,

The drive element 17 is constantly with the knot 22A connected and the output element 19 is constantly with the knot 56A connected.

The knot 26A is constantly with the knot 34A connected. The knot 36A is constantly with the knot 42A connected. The knot 44A is constant with the node 54A connected. The knot 22A is constantly with the knot 52A connected. The knot 24A is constantly with the knot 46A connected.

A first torque transmitting device, such as brake 80 , connects the node 24A selectively with the gearbox 60 , A second torque transmitting device, such as brake 82 , connects the node 32A selectively with the gearbox 60 , A third torque transmitting device, such as brake 84 , connects the node 36A selectively with the gearbox 60 , A fourth torque transmitting device, such as a clutch 85 , connects the node 22A selectively with the node 26A , A fifth torque transmitting device, such as a clutch 86 , connects the node 26A selectively with the node 56A ,

To establish gear ratios, two torque transmitting devices are engaged for each gear state. The engaged torque transmitting devices are each indicated by an "X" in each row in FIG 1b shown. For example, to make a reverse gear, the brake 80 and the clutch 86 indented. The brake 80 moves the knot 24A with the gearbox 60 one. The coupling 86 moves the knot 26A with the node 56A one. Similarly, the eight forward gears are achieved by different combinations of clutch engagement, as in 1b ,

The powertrain 10 may share components with a hybrid vehicle, and such a combination may be operable in a "charge depletion mode". For purposes of the present invention, a "charge depletion mode" is a mode in which the vehicle is primarily powered by an electric motor / generator so that a battery is depleted or nearly depleted when the vehicle reaches its destination. In other words, the machine becomes 12 during the charge depletion mode only to the extent necessary to ensure that the battery is not depleted before reaching the destination. A conventional hybrid vehicle operates in a "charge hold mode" in which, when the battery charge level drops below a predetermined level (eg, 25%), the engine is automatically run to recharge the battery. Therefore, by operating the hybrid vehicle in a charge-depleting mode, it may save some or all of the fuel that would otherwise be consumed to maintain the 25% battery charge level in a conventional hybrid vehicle. It should be noted that a hybrid vehicle powertrain is preferably operated in the charge-depleting mode only when the battery can be recharged after reaching the destination by connecting it to a power source.

Although the best embodiments of the invention in detail will be described to those skilled in the art Invention relates to various alternative constructions and embodiments for practicing the invention within the Scope of the appended claims recognize.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited non-patent literature

• - "The Lever Analogy: A New Tool in Transmission Analysis", 1981, written by Genford, Howard and Leising, Maurice [0040]

Claims (11)

Multi-speed transmission comprising: a drive element; one Output element; a first, second, third and fourth Planetary gear set, each having a first, second and third element exhibit; a first connecting element, which is the second element of the first planetary gear set constantly with the third element connects the second planetary gear set; a second connecting element, that the second element of the second planetary gear set constantly connects to the first element of the third planetary gear set; one third connecting element, which is the third element of the third planetary gear set constantly with the third element of the fourth planetary gear set links; a fourth connecting element, which is the first element of the first planetary gear set constantly with the first element connects the fourth planetary gear set; a fifth Connecting element, which is the third element of the first planetary gear set constantly with the second element of the third planetary gear set links; and five torque transmission devices, around the elements of the planetary gear sets selectively with other elements planetary gear sets or with a fixed element to connect, the five torque transmitting devices in combinations of two are engaged by at least eight Forward gears and at least one reverse gear make between the drive element and the output element. Transmission according to claim 1, wherein a first of the five Torque transmission facilities serves the third Element of the first planetary gear set selectively with the fixed one Element to connect. Transmission according to claim 2, wherein a second of the five Torque transmission devices serves the first Element of the second planetary gear set selectively with the fixed Element to connect. Transmission according to claim 3, wherein a third of the five Torque transmission devices serves the second Element of the second planetary gear set selectively with the fixed Element to connect. Transmission according to claim 4, wherein a fourth of the five Torque transmission devices serves the first Element of the first planetary gear set selectively with the second element to connect the first planetary gear set. Transmission according to claim 5, wherein a fifth of the five torque transmitting devices thereto serves, the second element of the first planetary gear set selectively to connect with the second element of the fourth planetary gear set. Transmission according to claim 1, wherein three of the five torque transmitting devices Include brakes; and the other two of the five torque transmitting devices Include couplings. Transmission according to claim 1, wherein the first, second and third element of the first, second, third and fourth planetary gear set a sun gear, a planet carrier arrangement or a ring gear include. Transmission according to claim 1, wherein the drive element constantly with the first element of the first planetary gear set is connected and the output element constantly with the second Element of the fourth planetary gear set is connected. A multi-speed transmission comprising: a drive element; an output element; first, second, third and fourth planetary gear sets each having first, second and third elements; wherein the drive element is continuously connected to the first element of the first planetary gear set; wherein the output member is continuously connected to the second element of the fourth planetary gear set; a first connecting member continuously connecting the second member of the first planetary gear set to the third member of the second planetary gear set; a second connecting member continuously connecting the second member of the second planetary gear set to the first member of the third planetary gear set; a third link continuously connecting the third element of the third planetary gear set with the third element of the fourth planetary gear set; a fourth link continuously connecting the first member of the first planetary gear set to the first member of the fourth planetary gear set; a fifth link continuously connecting the third member of the first planetary gear set with the second member of the third planetary gear set; a first torque transmitting device which is the third element of the first planetary gear set connectively with a fixed element; second torque transmitting means selectively connecting the first member of the second planetary gear set to the stationary member; a third torque transmitting device selectively connecting the second member of the second planetary gear set with the stationary member; fourth torque transmitting means selectively connecting the first member of the first planetary gear set to the second member of the first planetary gear set; a fifth torque transmitting device selectively connecting the second member of the first planetary gear set with the second member of the fourth planetary gear set; and wherein the torque transmitting devices are engaged in combinations of two to establish at least eight forward gears and at least one reverse gear between the input member and the output member. Multi-speed transmission comprising: a drive element; one Output element; a first, second, third and fourth Planetary gear, each a sun gear, a planet carrier arrangement and a ring gear; the drive element constantly is connected to the sun gear of the first planetary gear set; in which the output element constantly with the planet carrier arrangement the fourth planetary gear set is connected; a first connecting element, the planet carrier arrangement of the first planetary gear set constantly connects to the ring gear of the second planetary gear set; one second connecting element, the planet carrier arrangement of the second planetary gear set constantly with the sun gear connects the third planetary gear set; a third connecting element, that the ring gear of the third planetary gear constantly with connects the ring gear of the fourth planetary gear set; a fourth Connecting element, which is the sun gear of the first planetary gear set constantly with the sun gear of the fourth planetary gear set links; a fifth connecting element that the Ring gear of the first planetary gear set constantly with the planet carrier assembly connects the third planetary gear set; a first torque transmitting device, the selectively the ring gear of the first planetary gear set with the fixed Element connects; a second torque transmitting device, the the sun gear of the second planetary gear set selectively with the fixed one Element connects; a third torque transmitting device, the planet carrier arrangement of the second planetary gear set selectively connects to the fixed element; a fourth Torque transmission device, which is the sun gear of first planetary gearset selectively with the planet carrier assembly connects the first planetary gear set; a fifth Torque transmission device, the planet carrier assembly of the first planetary gear set selectively with the planet carrier assembly of fourth planetary gear set connects; and wherein the torque transmitting devices in combinations of two are engaged, at least eight forward gears and at least one reverse gear make between the drive element and the output element.