Planetary gear train of automatic transmission for vehicle

The present application claims priority to Korean Patent Application No.-2017-0135814 filed on Oct. 19, 2017, the entire contents of which is incorporated herein for all purposes by this reference.

The present invention relates to an automatic transmission for a vehicle.

In the field of an automatic transmission, more multiplicity of shift-stages is useful technology for enhancement of fuel consumption and drivability of a vehicle.

In this sense, research for an engine has been made to achieve weight reduction and to enhance fuel consumption by so-called downsizing and research on an automatic transmission has been performed to simultaneously provide better drivability and fuel consumption by achieving more shift stages.

To achieve more shift-stages for an automatic transmission, the number of parts is typically increased, which may deteriorate installability, a production cost, weight and/or power flow efficiency.

Therefore, to maximally enhance fuel consumption of an automatic transmission having more shift-stages, it is important that better efficiency is derived by less number of parts.

In this background, an eight-speed automatic transmission has been introduced recently and a planetary gear train for an automatic transmission facilitating more shift-stages is under investigation.

In addition, a recent eight-speed automatic transmission typically shows a gear ratio span in a level of 6.5 to 7.5, which may require improvement for better fuel consumption.

In the case of a gear ratio span of an eight-speed automatic transmission having a level above 9.0, it is difficult to maintain step ratios between adjacent shift stages to be linear, by which driving efficiency of an engine and drivability of a vehicle deteriorated. Thus, research studies are underway for developing a high efficiency automatic transmission having nine or more speeds.

The information included in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and may not be taken as an acknowledgment or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Various aspects of the present invention are directed to providing a planetary gear train of an automatic transmission for a vehicle facilitating at least nine forward speeds, providing better performance and fuel efficiency of a vehicle.

A planetary gear train according to an exemplary embodiment of the present invention may include an input shaft receiving an engine torque, an output shaft outputting a shifted torque, a first planetary gear set having first, second and third rotation elements, a second planetary gear set having fourth, fifth, and sixth rotation elements, a third planetary gear set having seventh, eighth, and ninth rotation elements, a fourth planetary gear set having tenth, eleventh, and twelfth rotation elements, and a fifth planetary gear set having thirteenth, fourteenth, and fifteenth rotation elements. An exemplary planetary gear train may further include a first shaft fixedly connected to the first rotation element and the eleventh rotation element, and fixedly connected to the input shaft, a second shaft fixedly connected to the second rotation element and one rotation element of the fifth planetary gear set, selectively connectable to the input shaft, and selectively connectable to the transmission housing, a third shaft fixedly connected to the eighth rotation element and fixedly connected to the output shaft, a fourth shaft fixedly connected to the third rotation element and the fifth rotation element, a fifth shaft fixedly connected to the sixth rotation element, the seventh rotation element, the tenth rotation element, and another rotation element of the fifth planetary gear set which is not connected to the second shaft, a sixth shaft fixedly connected to the twelfth rotation element, a seventh shaft fixedly connected to a remaining rotation element of the fifth planetary gear set which is not connected to the first shaft and the second shaft, and a plurality of shafts each of which is selectively connectable to the transmission housing and fixedly connected to a rotation element of the second and third planetary gear sets which is not fixedly connected to any of the first to seventh shafts.

The plurality of shafts may include an eighth shaft fixedly connected to the fourth rotation element and selectively connectable to the transmission housing, and a ninth shaft fixedly connected to the ninth rotation element and selectively connectable to the transmission housing.

The exemplary planetary gear set may further include three clutches selectively connecting a corresponding pair among the input shaft, the output shaft, and the nine shafts, and three brakes selectively connecting the second shaft, the eighth shaft, and the ninth shaft to the transmission housing respectively,

The thirteenth rotation element is fixedly connected to the seventh shaft. The fourteenth rotation element is fixedly connected to the second shaft. The fifteenth rotation element is fixedly connected to the fifth shaft. The third shaft and the sixth shaft, the fifth shaft and the seventh shaft, and the input shaft and the second shaft may be selectively interconnected respectively.

The exemplary planetary gear set may further include three clutches selectively connecting a corresponding pair among the input shaft, the output shaft, and the nine shafts, and three brakes selectively connecting the second shaft, the eighth shaft, and the ninth shaft to the transmission housing respectively,

The thirteenth rotation element may be fixedly connected to the seventh shaft. The fourteenth rotation element may be fixedly connected to the fifth shaft. The fifteenth rotation element may be fixedly connected to the second shaft. The third shaft and the sixth shaft, the fifth shaft and the seventh shaft, and the input shaft and the second shaft may be selectively interconnected respectively.

The three clutches may include a first clutch disposed between the third shaft and the sixth shaft, a second clutch disposed between the fifth shaft and the seventh shaft, and a third clutch disposed between the input shaft and the second shaft. The three brakes may include a first brake disposed between the second shaft and the transmission housing, a second brake disposed between the eighth shaft and the transmission housing, and a third brake disposed between the ninth shaft and the transmission housing.

The exemplary planetary gear set may further include three clutches selectively connecting a corresponding pair among the input shaft, the output shaft, and the nine shafts, and three brakes selectively connecting the second shaft, the eighth shaft, and the ninth shaft to the transmission housing respectively,

The thirteenth rotation element may be fixedly connected to the seventh shaft. The fourteenth rotation element may be fixedly connected to the fifth shaft. The fifteenth rotation element may be fixedly connected to the second shaft. The third shaft and the sixth shaft, the second shaft and the seventh shaft, and the input shaft and the second shaft are selectively connectable to respectively.

The exemplary planetary gear set may further include three clutches selectively connecting a corresponding pair among the input shaft, the output shaft, and the nine shafts, and three brakes selectively connecting the second shaft, the eighth shaft, and the ninth shaft to the transmission housing respectively,

The thirteenth rotation element may be fixedly connected to the seventh shaft. The fourteenth rotation element may be fixedly connected to the second shaft. The fifteenth rotation element may be fixedly connected to the fifth shaft. The third shaft and the sixth shaft, the second shaft and the seventh shaft, and the input shaft and the second shaft are selectively connectable to respectively.

The exemplary planetary gear set may further include three clutches selectively connecting a corresponding pair among the input shaft, the output shaft, and the nine shafts, and three brakes selectively connecting the second shaft, the eighth shaft, and the ninth shaft to the transmission housing respectively,

The thirteenth rotation element may be fixedly connected to the second shaft. The fourteenth rotation element may be fixedly connected to the fifth shaft. The fifteenth rotation element may be fixedly connected to the seventh shaft. The third shaft and the sixth shaft, the second shaft and the seventh shaft, and the input shaft and the second shaft are selectively connectable to respectively.

The three clutches may include a first clutch disposed between the third shaft and the sixth shaft, a second clutch disposed between the second shaft and the seventh shaft, and a third clutch disposed between the input shaft and the second shaft. The three brakes may include a first brake disposed between the second shaft and the transmission housing, a second brake disposed between the eighth shaft and the transmission housing, and a third brake disposed between the ninth shaft and the transmission housing.

The first, second and third rotation elements may be a first sun gear, a first planet carrier, and a first ring gear. The fourth, fifth, and sixth rotation elements may be a second sun gear, a second planet carrier, and a second ring gear. The seventh, eighth, and ninth rotation elements may be a third sun gear, a third planet carrier, and a third ring gear. The tenth, eleventh, and twelfth rotation elements may be a fourth sun gear, a fourth planet carrier, and a fourth ring gear. The thirteenth, fourteenth, and fifteenth rotation elements may be a fifth sun gear, a fifth planet carrier, and a fifth ring gear.

The first, second, third, fourth, and fifth planetary gear sets may be disposed in the order of the first, fifth, second, third, and fourth planetary gear sets from an engine side.

A planetary gear train according to an exemplary embodiment of the present invention may realize at least nine forward speeds and at least one reverse speed formed by operating the four planetary gear sets as simple planetary gear sets by controlling six engagement elements.

Furthermore, a planetary gear train according to an exemplary embodiment of the present invention may realize a gear ratio span of more than 9.1, maximizing efficiency of driving an engine.

While employing five planetary gear sets for nine forward speeds and one reverse speed, engagement elements are minimally employed, reducing drag loss of clutches and brakes, and accordingly improving power delivery efficiency and fuel consumption.

Furthermore, a torque-in-parallel scheme is applied to an output-side planetary gear set, and torque loads of planetary gear sets and engagement elements may become more uniform, such that torque delivery efficiency and durability may be enhanced.

While realizing nine forward speeds and one reverse speed, flexibility of output gear ratio is increased, enhancing linearity of step ratios of shift-stages.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.

FIG. 1 is a schematic diagram of a planetary gear train according to various exemplary embodiments of the present invention.

FIG. 2 is an operational chart for respective control elements at respective shift-stages applicable to a planetary gear train according to various exemplary embodiments of the present invention.

FIG. 3 is a schematic diagram of a planetary gear train according to various exemplary embodiments of the present invention.

FIG. 4 is a schematic diagram of a planetary gear train according to various exemplary embodiments of the present invention.

FIG. 5 is a schematic diagram of a planetary gear train according to various exemplary embodiments of the present invention.

FIG. 6 is a schematic diagram of a planetary gear train according to various exemplary embodiments of the present invention.

It may be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as included herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particularly intended application and use environment.

In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.

Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

Hereinafter, an exemplary embodiment of the present invention will be described more specifically with reference to drawings.

The drawings and description are to be regarded as illustrative in nature and not restrictive, and like reference numerals designate like elements throughout the specification.

In the following description, dividing names of components into first, second, and the like is to divide the names because the names of the components are the same as each other and an order thereof is not particularly limited.

FIG. 1 is a schematic diagram of a planetary gear train according to various exemplary embodiments of the present invention.

Referring to FIG. 1 , a planetary gear train according to various exemplary embodiments of the present invention may include first, second, third, fourth, and fifth planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 disposed on a same axis, an input shaft IS, an output shaft OS, nine shafts TM 1 to TM 9 interconnecting rotation elements of the first, second, third, fourth, and fifth planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 , engagement elements of three clutches C 1 to C 3 and three brakes B 1 to B 3 , and a transmission housing H.

A torque received from an engine through the input shaft is changed by cooperative operation of the first, second, third, fourth, and fifth planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 , and a shifted torque is output through the output shaft OS.

In the various exemplary embodiments, the planetary gear sets are disposed in the order of the first, the fifth, and the second, third, and fourth planetary gear sets (PG 1 , PG 5 , PG 2 , PG 3 , PG 4 ), from an engine side.

The input shaft is an input member and the torque from a crankshaft of an engine is input into the input shaft IS, after being torque-converted through a torque converter.

The output shaft OS is an output element disposed on a same axis with the input shaft IS, and outputs a shifted driving torque to a driveshaft through a differential apparatus.

The first planetary gear set PG 1 is a single pinion planetary gear set, and may include a first sun gear S 1 , a first planet carrier PC 1 rotatably supporting a plurality of first pinion gears P 1 externally gear-meshed with the first sun gear S 1 , and a first ring gear R 1 internally gear-meshed with the plurality of first pinion gears P 1 . The first sun gear S 1 acts as a first rotation element N 1 , the first planet carrier PC 1 acts as a second rotation element N 2 , and the first ring gear R 1 acts as a third rotation element N 3 .

The second planetary gear set PG 2 is a single pinion planetary gear set, and may include a second sun gear S 2 , a second planet carrier PC 2 rotatably supporting a plurality of second pinion gears P 2 externally gear-meshed with the second sun gear S 2 , and a second ring gear R 2 internally gear-meshed with the plurality of second pinion gears P 2 . The second sun gear S 2 acts as a fourth rotation element N 4 , the second planet carrier PC 2 acts as a fifth rotation element N 5 , and the second ring gear R 2 acts as a sixth rotation element N 6 .

The third planetary gear set PG 3 is a single pinion planetary gear set, and may include a third sun gear S 3 , a third planet carrier PC 3 rotatably supporting a plurality of third pinion gears P 3 externally gear-meshed with the third sun gear S 3 , and a third ring gear R 3 internally gear-meshed with the plurality of third pinion gears P 3 . The third sun gear S 3 acts as a seventh rotation element N 7 , the third planet carrier PC 3 acts as an eighth rotation element N 8 , and the third ring gear R 3 acts as a ninth rotation element N 9 .

The fourth planetary gear set PG 4 is a single pinion planetary gear set, and may include a fourth sun gear S 4 , a fourth planet carrier PC 4 rotatably supporting a plurality of fourth pinion gears P 4 externally gear-meshed with the fourth sun gear S 4 , and a fourth ring gear R 4 internally gear-meshed with the plurality of fourth pinion gears P 4 . The fourth sun gear S 4 acts as a tenth rotation element N 10 , the fourth planet carrier PC 4 acts as an eleventh rotation element N 11 , and the fourth ring gear R 4 acts as a twelfth rotation element N 12 .

The fifth planetary gear set PG 5 is a single pinion planetary gear set, and may include a fifth sun gear S 5 , a fifth planet carrier PC 5 rotatably supporting a plurality of fifth pinion gears P 5 externally gear-meshed with the fifth sun gear S 5 , and a fifth ring gear R 5 internally gear-meshed with the plurality of fifth pinion gears P 5 . The fifth sun gear S 5 acts as a thirteenth rotation element N 13 , the fifth planet carrier PC 5 acts as a fourteenth rotation element N 14 , and the fifth ring gear R 5 acts as a fifteenth rotation element N 15 .

In the first, second, third, fourth, and fifth planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 , the first rotation element N 1 and the eleventh rotation element N 11 are fixedly interconnected, the second rotation element N 2 and the fourteenth rotation element N 14 are fixedly interconnected, the third rotation element N 3 and the fifth rotation element N 5 are fixedly interconnected, the sixth rotation element N 6 , the seventh rotation element N 7 , the tenth rotation element N 01 , and the fifteenth rotation element N 15 are fixedly interconnected, and nine shafts TM 1 to TM 9 are formed.

The nine shafts TM 1 to TM 9 are hereinafter described in detail.

The first shaft TM 1 is fixedly connected to first rotation element N 1 (first sun gear S 1 ) and eleventh rotation element N 11 (fourth planet carrier PC 4 ), and fixedly connected to the input shaft IS, constantly acting as an input element.

The second shaft TM 2 is fixedly connected to second rotation element N 2 (first planet carrier PC 1 ) and fourteenth rotation element N 14 (fifth planet carrier PC 5 ).

The third shaft TM 3 is fixedly connected to the eighth rotation element N 8 (third planet carrier PC 3 ), and fixedly connected to the output shaft OS constantly acting as an output element.

The fourth shaft TM 4 is fixedly connected to third rotation element N 3 (first ring gear R 1 ) and fifth rotation element N 5 (second planet carrier PC 2 ).

The fifth shaft TM 5 is fixedly connected to the sixth rotation element N 6 (second ring gear R 2 ), the seventh rotation element N 7 (third sun gear S 3 ), the tenth rotation element N 10 (fourth sun gear S 4 ), and the fifteenth rotation element N 15 (fifth ring gear R 5 ).

The sixth shaft TM 6 is fixedly connected to the twelfth rotation element N 12 (fourth ring gear R 4 ).

The seventh shaft TM 7 is fixedly connected to the thirteenth rotation element N 13 (fifth sun gear S 5 ).

The eighth shaft TM 8 is fixedly connected to the fourth rotation element N 4 (second sun gear S 2 ).

The ninth shaft TM 9 is fixedly connected to the ninth rotation element N 9 (third ring gear R 3 ).

Each of the nine shafts TM 1 to TM 9 may be a rotation member that fixedly interconnects the input and output shafts and rotation elements of the planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 , or may be a rotation member that selectively interconnects a rotation element to the transmission housing H, or may be a fixed member fixed to the transmission housing H.

In the disclosure, when two or more members are described to be “fixedly connected”, where the member may be any of a shaft, an input shaft, an output shaft, a rotation member, and a transmission housing, it means that the fixedly connected members always rotate at a same speed.

When two or more members are described to be “selectively connectable” by an engagement element, it means that the selectively connectable members rotates separately when the engagement element is not engaged, and rotates at a same speed when the engagement element is engaged. It may be understood that in the case that a member is “selectively connectable” with a transmission housing by an engagement element, the member may be stationary when the engagement element is engaged.

The third shaft TM 3 is selectively connectable to the sixth shaft TM 6 , the fifth shaft TM 5 is selectively connectable to the seventh shaft TM 7 , and the input shaft is selectively connectable to the second shaft TM 2 .

The eighth shaft TM 8 , ninth shaft TM 9 , and second shaft TM 2 are selectively connectable to the transmission housing H, selectively acting as fixed elements respectively.

The three engagement elements of clutches C 1 , C 2 , and C 3 are disposed between the nine shafts TM 1 to TM 9 , the input shaft IS, and the output shaft OS, to form selective connections.

The three engagement elements of brakes B 1 , B 2 , and B 3 are disposed between the nine shafts TM 1 to TM 9 and the transmission housing H, to form selective connections.

The six engagement element of the three clutches C 1 to C 3 and the three brakes B 1 to B 3 are disposed as follows.

The first clutch C 1 is disposed between the third shaft TM 3 and the sixth shaft TM 6 , and selectively connects the third shaft TM 3 and the sixth shaft TM 6 , controlling power delivery therebetween.

The second clutch C 2 is disposed between the fifth shaft TM 5 and the seventh shaft TM 7 , and selectively connects the fifth shaft TM 5 and the seventh shaft TM 7 , controlling power delivery therebetween.

The third clutch C 3 is disposed between the input shaft IS and the second shaft TM 2 , and selectively connects the input shaft IS and the second shaft TM 2 , controlling power delivery therebetween.

The first brake B 1 is disposed between the eighth shaft TM 8 and the transmission housing H, and selectively connects the eighth shaft TM 8 to the transmission housing H.

The second brake B 2 is disposed between the ninth shaft TM 9 and the transmission housing H, and selectively connects the ninth shaft TM 9 to the transmission housing H.

The third brake B 3 is disposed between the second shaft TM 2 and the transmission housing H, and selectively connects the second shaft TM 2 to the transmission housing H.

Referring to FIG. 1 , the third clutch C 3 has been described to selectively connect the second shaft TM 2 to the input shaft IS. However, since the input shaft IS and the first shaft TM 1 are always interconnected, the third clutch C 3 may selectively connect the first shaft TM 1 and the second shaft TM 2 , and the present configuration may be interpreted as equivalent.

The engagement elements of the first, second and third clutches C 1 , C 2 , and C 3 and the first, second and third brakes B 1 , B 2 , and B 3 may be realized as multi-plate hydraulic pressure friction devices that are frictionally engaged by hydraulic pressure, however, it may not be understood to be limited thereto, since various other configuration that are electrically controllable may be available.

FIG. 2 is an operational chart for respective control elements at respective shift-stages applicable to a planetary gear train according to various exemplary embodiments of the present invention.

referring to FIG. 2 , a planetary gear train according to various exemplary embodiments realizes nine forward speeds and one reverse speed by operating three engagements among the first, second and third clutches C 1 , C 2 , and C 3 and first, second and third brakes B 1 , B 2 , and B 3 .

In the first forward speed D 1 , the second clutch C 2 and the first and second brakes B 1 and B 2 are simultaneously operated.

As a result, the fifth shaft TM 5 and the seventh shaft TM 7 are connected by the operation of the second clutch C 2 . In the present state, a torque is input to the first shaft TM 1 .

In such a state, the eighth and ninth shafts TM 8 and TM 9 act as fixed elements by the operation of the first and second brakes B 1 and B 2 , realizing the first forward speed and outputting a shifted torque to the output shaft OS connected to the third shaft TM 3 .

In the second forward speed D 2 , the second and third clutches C 2 and C 3 and the second brake B 2 are simultaneously operated.

As a result, the fifth shaft TM 5 and the seventh shaft TM 7 are connected by the operation of the second clutch C 2 , and the input shaft IS and the second shaft TM 2 are connected by the operation of the third clutch C 3 . In the present state, a torque is input to the first shaft TM 1 and the second shaft TM 2 .

Furthermore, the ninth shaft TM 9 acts as a fixed element by the operation of the second brake B 2 , realizing the second forward speed and outputting a shifted torque to the output shaft OS connected to the third shaft TM 3 .

In the third forward speed D 3 , the third clutch C 3 and the first and second brakes B 1 and B 2 are simultaneously operated.

As a result, the input shaft IS and the second shaft TM 2 are connected by the operation of the third clutch C 3 . In the present state, a torque is input to the first shaft TM 1 and the second shaft TM 2 .

In such a state, the eighth and ninth shafts TM 8 and TM 9 act as fixed elements by the operation of the first and second brakes B 1 and B 2 , realizing the third forward speed and outputting a shifted torque to the output shaft OS connected to the third shaft TM 3 .

In the fourth forward speed D 4 , the first clutch C 1 and the first and second brakes B 1 and B 2 are simultaneously operated.

As a result, the third shaft TM 3 and the sixth shaft TM 6 are connected by the operation of the first clutch C 1 . In the present state, a torque is input to the first shaft TM 1 .

In such a state, the eighth and ninth shafts TM 8 and TM 9 act as fixed elements by the operation of the first and second brakes B 2 , realizing the fourth forward speed and outputting a shifted torque to the output shaft OS connected to the third shaft TM 3 .

In the fifth forward speed D 5 , the first and third clutches C 1 and C 3 and the first brake B 1 are simultaneously operated.

As a result, the third shaft TM 3 and the sixth shaft TM 6 are connected by the operation of the first clutch C 1 , and the input shaft IS and the second shaft TM 2 are connected by the operation of the third clutch C 3 . In the present state, a torque is input to the first shaft TM 1 and the second shaft TM 2 .

Furthermore, the eighth shaft TM 8 acts as a fixed element by the operation of the first brake B 1 , realizing the fifth forward speed and outputting a shifted torque to the output shaft OS connected to the third shaft TM 3 .

In the forward sixth forward speed D 6 , the first, second and third clutches C 1 , C 2 , and C 3 are simultaneously operated.

As a result, the third shaft TM 3 and the sixth shaft TM 6 are connected by the operation of the first clutch C 1 , the fifth shaft TM 5 and the seventh shaft TM 7 are connected by the operation of the second clutch C 2 , and the input shaft IS and the second shaft TM 2 are connected by the operation of the third clutch C 3 .

As such, the first, second, third, fourth, and fifth planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 integrally rotate, realizing the forward sixth forward speed where a torque is output as inputted and outputting a shifted torque through the output shaft OS connected to the third shaft TM 3 .

In the seventh forward speed D 7 , the first and second clutch C 1 and C 2 and the first brake B 1 are simultaneously operated.

As a result, the third shaft TM 3 and the sixth shaft TM 6 are connected by the operation of the first clutch C 1 , and the fifth shaft TM 5 and the seventh shaft TM 7 are connected by the operation of the second clutch C 2 . In the present state, a torque is input to the first shaft TM 1 .

Furthermore, the eighth shaft TM 8 acts as a fixed element by the operation of the first brake B 1 , realizing the seventh forward speed and outputting a shifted torque to the output shaft OS connected to the third shaft TM 3 .

In the eighth forward speed D 8 , the first and second clutch C 1 and C 2 and the third brake B 3 are simultaneously operated.

As a result, the third shaft TM 3 and the sixth shaft TM 6 are connected by the operation of the first clutch C 1 , and the fifth shaft TM 5 and the seventh shaft TM 7 are connected by the operation of the second clutch C 2 . In the present state, a torque is input to the first shaft TM 1 .

Furthermore, the ninth shaft TM 9 acts as a fixed element by the operation of the third brake B 3 , realizing the eighth forward speed and outputting a shifted torque to the output shaft OS connected to the third shaft TM 3 .

In the ninth forward speed D 9 , the first clutch Cl and the first and third brakes B 1 and B 3 are simultaneously operated.

As a result, the third shaft TM 3 and the sixth shaft TM 6 are connected by the operation of the first clutch C 1 . In the present state, a torque is input to the first shaft TM 1 .

In such a state, the eighth and second shafts TM 8 and TM 2 act as fixed elements by the operation of the first and third brakes B 1 and B 3 , realizing the ninth forward speed and outputting a shifted torque to the output shaft OS connected to the third shaft TM 3 .

In the reverse speed REV, the first, second and third brakes B 1 , B 2 , and B 3 are simultaneously operated.

As such, the eighth, ninth, and second shafts TM 8 , TM 9 , and TM 2 act as fixed elements by the operation of the first, second and third brakes B 1 , B 2 , and B 3 , and a torque is input to the first shaft TM 1 , realizing the reverse speed and outputting a reverse torque through the output shaft OS connected to the third shaft TM 3 .

FIG. 3 is a schematic diagram of a planetary gear train according to various exemplary embodiments of the present invention.

According to a planetary gear train according to various exemplary embodiments shown in FIG. 1 , the thirteenth rotation element N 13 is fixedly connected to the seventh shaft TM 7 , the fourteenth rotation element N 14 is fixedly connected to the second shaft TM 2 , and the fifteenth rotation element N 15 is fixedly connected to the fifth shaft TM 5 . In comparison, according to a planetary gear train according to various exemplary embodiments shown in FIG. 3 , the thirteenth rotation element N 13 is fixedly connected to the seventh shaft TM 7 , the fourteenth rotation element N 14 is fixedly connected to the fifth shaft TM 5 , and the fifteenth rotation element N 15 is fixedly connected to the second shaft TM 2 .

Although the various exemplary embodiments differs from the various exemplary embodiments in the fixed connections of the fifth planetary gear set PG 5 , operations and functions of the overall planetary gear train remains the same.

That is, the planetary gear train of the various exemplary embodiments may be operated by the same operational chart to achieve the same shaft-stages with the various exemplary embodiments.

FIG. 4 is a schematic diagram of a planetary gear train according to various exemplary embodiments of the present invention.

According to a planetary gear train according to various exemplary embodiments shown in FIG. 3 , the second clutch C 2 is disposed between the fifth shaft TM 5 and the seventh shaft TM 7 such that the fifth planetary gear set PG 5 integrally rotates by the operation of the second clutch C 2 . According to a planetary gear train according to various exemplary embodiments shown in FIG. 4 , the second clutch C 2 is disposed between the second shaft TM 2 and the seventh shaft TM 7 . It may be obviously understood that according to the various exemplary embodiments, the fifth planetary gear set PG 5 integrally rotates by the operation of the second clutch C 2 .

That is, although the various exemplary embodiments differs from the various exemplary embodiments in the location of the second clutch C 2 , the function and operation of the second clutch C 2 to integrally rotate the fifth planetary gear set PG 5 remains the same.

That is, the planetary gear train of the various exemplary embodiments may be operated by the same operational chart to achieve the same shaft-stages with the various exemplary embodiments.

FIG. 5 is a schematic diagram of a planetary gear train according to various exemplary embodiments of the present invention.

According to a planetary gear train according to various exemplary embodiments shown in FIG. 1 , the second clutch C 2 is disposed between the fifth shaft TM 5 and the seventh shaft TM 7 such that the fifth planetary gear set PG 5 integrally rotates by the operation of the second clutch C 2 . According to a planetary gear train according to various exemplary embodiments shown in FIG. 5 , the second clutch C 2 is disposed between the second shaft TM 2 and the seventh shaft TM 7 . It may be obviously understood that according to the various exemplary embodiments, the fifth planetary gear set PG 5 integrally rotates by the operation of the second clutch C 2 .

That is, although the various exemplary embodiments differs from the various exemplary embodiments in the location of the second clutch C 2 , the function and operation of the second clutch C 2 to integrally rotate the fifth planetary gear set PG 5 remains the same.

That is, the planetary gear train of the various exemplary embodiments may be operated by the same operational chart to achieve the same shaft-stages with the various exemplary embodiments.

FIG. 6 is a schematic diagram of a planetary gear train according to various exemplary embodiments of the present invention.

According to a planetary gear train according to various exemplary embodiments shown in FIG. 5 , the thirteenth rotation element N 13 is fixedly connected to the seventh shaft TM 7 , the fourteenth rotation element N 14 is fixedly connected to the second shaft TM 2 , and the fifteenth rotation element N 15 is fixedly connected to the fifth shaft TM 5 . In comparison, according to a planetary gear train according to various exemplary embodiments shown in FIG. 6 , the thirteenth rotation element N 13 is fixedly connected to the second shaft TM 2 , the fourteenth rotation element N 14 is fixedly connected to the fifth shaft TM 5 , and the fifteenth rotation element N 15 is fixedly connected to the seventh shaft TM 7 .

Although the various exemplary embodiments differs from the various exemplary embodiments in the fixed connections of the fifth planetary gear set PG 5 , operations and functions of the overall planetary gear train remains the same.

That is, the planetary gear train of the various exemplary embodiments may be operated by the same operational chart to achieve the same shaft-stages with the various exemplary embodiments,

A planetary gear train according to an exemplary embodiment of the present invention may realize nine forward speeds and one reverse speed by controlling five planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 by three clutches C 1 , C 2 , and C 3 and three brakes B 1 , B 2 , and B 3 .

Furthermore, a planetary gear train according to an exemplary embodiment of the present invention may realize a gear ratio span of more than 9.1, maximizing efficiency of driving an engine.

While employing five planetary gear sets for nine forward speeds and one reverse speed, engagement elements are minimally employed, reducing drag loss of clutches and brakes, and accordingly improving power delivery efficiency and fuel consumption.

Furthermore, a torque-in-parallel scheme is applied to an output-side planetary gear set, and torque loads of planetary gear sets and engagement elements may become more uniform, such that torque delivery efficiency and durability may be enhanced.

While realizing nine forward speeds and one reverse speed, flexibility of output gear ratio is increased, enhancing linearity of step ratios of shift-stages.

For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “internal”, “outer”, “up”, “down”, “upper”, “lower”, “upwards”, “downwards”, “front”, “rear”, “back”, “inside”, “outside”, “inwardly”, “outwardly”, “internal”, “external”, “internal”, “outer”, “forwards”, and “backwards” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described to explain certain principles of the invention and their practical application, to enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.