Planetary gear train of automatic transmission for vehicle

This application claims priority to and the benefit of Korean Patent Application No. 10-2017-0058314, filed on May 10, 2017, which is incorporated herein by reference in its entirety.

The present disclosure relates to an automatic transmission for a vehicle. More particularly, the present disclosure relates to a planetary gear train of an automatic transmission for a vehicle that improves power delivery performance and fuel economy.

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

Generally, an automatic transmission achieving more speed stages has been developed to enhance fuel economy and improve drivability.

Such an automatic transmission achieving more speed stages allows to improve power performance and driving efficiency when downsizing an engine. Providing high efficiency multiple-speeds transmissions with smooth step ratios that can be used as an index closely related to drivability such as acceleration before and after a shift increases competitiveness of an automatic transmission in the automotive field.

However, in the automatic transmission, as the number of speed stages increase, the number of internal components increase, and as a result, mountability, cost, weight, transmission efficiency, and the like may still deteriorate.

Accordingly, development of a planetary gear train that improves efficiency with a small number of components may be provided in order to increase a fuel efficiency enhancement effect through the multiple-speeds.

An eight-speed automatic transmission has been introduced recently and a planetary gear train for an automatic transmission enabling more speed stages has been developed.

However, since a conventional eight-speed automatic transmission has gear ratio span of 6.5-7.5 (gear ratio span is an important factor for securing linearity of step ratios), improvement of power performance and fuel economy may be minimal.

In addition, if an eight-speed automatic transmission has a gear ratio span larger than 9.0, we have also found that it is difficult to secure linearity of step ratios. Therefore, driving efficiency of an engine and drivability of a vehicle may be deteriorated, and thus, development of high efficiency automatic transmissions which achieve at least nine forward speed stages is desired.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.

The present disclosure provides a planetary gear train of an automatic transmission for a vehicle capable of improving power delivery performance and fuel economy by achieving ten forward speed stages and one reverse speed stage and reducing drag loss of clutches and brakes using five planetary gear sets and six engaging elements.

Another form of the present disclosure provides a planetary gear train of an automatic transmission for a vehicle having further capability of improving torque delivery efficiency and durability by using a planetary gear set of an output side in torque parallel type and minimizing torque share of each planetary gear set and each engaging element.

Yet another form of the present disclosure provides a high-efficiency planetary gear train of an automatic transmission for a vehicle that increases flexibility of output gear ratios and improves linearity of step ratios by using five planetary gear sets for achieving ten forward speed stages and one reverse speed stage.

A planetary gear train of an automatic transmission for a vehicle according to an exemplary form of the present disclosure may include: an input shaft configured to receive torque of an engine; an output shaft configured to output torque; a first planetary gear set including first, second, and third rotation elements; a second planetary gear set including fourth, fifth, and sixth rotation elements; a third planetary gear set including seventh, eighth, and ninth rotation elements; a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements; a fifth planetary gear set including thirteenth, fourteenth, and fifteenth rotational elements; a first shaft directly connected with the third rotation element and the input shaft; a second shaft directly connected with the fourteenth rotation element and the output shaft; a third shaft directly connected with the fifth rotation element and the thirteenth rotation element; a fourth shaft directly connected with the second rotation element, the eighth rotation element, and the fifteenth rotation element; a fifth shaft directly connected with the ninth rotation element and the eleventh rotation element; a sixth shaft directly connected with the first rotation element and the fourth rotation element; a seventh shaft directly connected with the sixth rotation element; an eighth shaft directly connected with the seventh rotation element and the tenth rotation element; and a ninth shaft directly connected with the twelfth rotation element.

The planetary gear train may further include: six engaging elements configured to selectively connect any one shaft of the nine shafts with another shaft of the nine shafts or selectively connect at least one shaft of the nine shafts with a transmission housing, wherein any one of forward speed stages or a reverse speed stage is achieved by operating three engaging elements among the six engaging elements.

The six engaging elements may include: three clutches, any one thereof connecting any two shafts among the nine shafts; and three brakes, any one thereof selectively connecting any shaft among the nine shafts that is not connected with the input shaft or the output shaft with the transmission housing.

The six engaging elements may include: a first clutch disposed between the second shaft and the sixth shaft; a second clutch disposed between the fifth shaft and the sixth shaft; a third clutch disposed between the fifth shaft and the seventh shaft; a first brake disposed between the third 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 rotational elements may be the first sun gear, the first planet carrier, and the first ring gear respectively, the fourth, fifth, and sixth rotational elements may be the second sun gear, the second planet carrier, and the second ring gear respectively, the seventh, eighth, and ninth rotational elements may be the third sun gear, the third planet carrier, and the third ring gear respectively, the tenth, eleventh, and twelfth rotational elements may be the fourth sun gear, the fourth planet carrier, and the fourth ring gear respectively, and the thirteenth, fourteenth, and fifteenth rotational elements may be the fifth sun gear, the fifth planet carrier, and the fifth ring gear respectively.

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

A planetary gear train of an automatic transmission for a vehicle according to another exemplary form of the present disclosure may include: an input shaft configured to receive torque of an engine; an output shaft configured to output torque; a first planetary gear set including first, second, and third rotation elements; a second planetary gear set including fourth, fifth, and sixth rotation elements; a third planetary gear set including seventh, eighth, and ninth rotation elements; a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements; a fifth planetary gear set including thirteenth, fourteenth, and fifteenth rotational elements; a first shaft directly connected with the third rotation element and the input shaft; a second shaft directly connected with the fourteenth rotation element and the output shaft; a third shaft directly connected with the fifth rotation element and the thirteenth rotation element; a fourth shaft directly connected with the second rotation element, the eighth rotation element, and fifteenth rotation element; a fifth shaft directly connected with the ninth rotation element and the eleventh rotation element; a sixth shaft directly connected with the first rotation element and the fourth rotation element; a seventh shaft directly connected with the sixth rotation element; and a plurality of shafts selectively and respectively connected with a transmission housing while directly and respectively connected with at least one rotation element of remaining rotation elements of the third and fourth planetary gear sets that are not connected to the first, second, third, fourth, fifth, sixth and seventh shafts, and the third shaft configured to selectively connected to the transmission housing.

The plurality of shafts may include: an eighth shaft directly connected with the seventh rotation element and the tenth rotation element; and a ninth shaft directly connected with the twelfth rotation element.

The planetary gear train may further include: three clutches each configured to selectively connect any two shafts among the nine shafts; and three brakes each configured to selectively connect at least one shaft among the nine shafts that is not connected with the input shaft or the output shaft with the transmission housing.

The three clutches may include: a first clutch disposed between the second shaft and the sixth; a second clutch disposed between the fifth shaft and the sixth shaft; and a third clutch disposed between the fifth shaft and the seventh shaft.

The three brakes may include: a first brake disposed between the third 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 rotational elements may be the first sun gear, the first planet carrier, and the first ring gear respectively, the fourth, fifth, and sixth rotational elements may be the second sun gear, the second planet carrier, and the second ring gear respectively, the seventh, eighth, and ninth rotational elements may be the third sun gear, the third planet carrier, and the third ring gear respectively, the tenth, eleventh, and twelfth rotational elements may be the fourth sun gear, the fourth planet carrier, and the fourth ring gear respectively, and the thirteenth, fourteenth, and fifteenth rotational elements may be the fifth sun gear, the fifth planet carrier, and the fifth ring gear respectively.

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

A planetary gear train of an automatic transmission for a vehicle according to other exemplary form of the present disclosure may include: an input shaft configured to receive torque of an engine; an output shaft configured to output torque; a first planetary gear set including first, second, and third rotation elements; a second planetary gear set including fourth, fifth, and sixth rotation elements; a third planetary gear set including seventh, eighth, and ninth rotation elements; a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements; a fifth planetary gear set including thirteenth, fourteenth, and fifteenth rotational elements; a first shaft directly connected with the third rotation element and the input shaft; a second shaft directly connected with the fourteenth rotation element and the output shaft; a third shaft directly connected with the fifth rotation element and the thirteenth rotation element; a fourth shaft directly connected with the second rotation element, the eighth rotation element, and the fifteenth rotation element; a fifth shaft directly connected with the ninth rotation element and the eleventh rotation element; a sixth shaft directly connected with the first rotation element and the fourth rotation element; a seventh shaft directly connected with the sixth rotation element; and eighth and ninth shafts. In particular, each of the eighth and ninth shafts is configured to selectively connected with a transmission housing via at least one of brakes while directly connected with at least one rotation element of remaining rotation elements of the third and fourth planetary gear sets that are not connected to any shaft of the first, second, third, fourth, fifth, sixth and seventh shafts, and the third shaft is configured to selectively connected to the transmission housing.

The second shaft and the sixth shaft, the fifth shaft and the sixth shaft, and the fifth shaft and the seventh shaft may be selectively connected with each other via at least one of clutches, the eighth shaft may be directly connected with the seventh rotation element and the tenth rotation element, and the ninth shaft may be directly connected with the twelfth rotation element.

The clutches may include: a first clutch disposed between the second shaft and the sixth shaft; a second clutch disposed between the fifth shaft and the sixth shaft; and a third clutch disposed between the fifth shaft and the seventh shaft.

The brakes may include: a first brake disposed between the third 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 rotational elements may be the first sun gear, the first planet carrier, and the first ring gear respectively, the fourth, fifth, and sixth rotational elements may be the second sun gear, the second planet carrier, and the second ring gear respectively, the seventh, eighth, and ninth rotational elements may be the third sun gear, the third planet carrier, and the third ring gear respectively, the tenth, eleventh, and twelfth rotational elements may be the fourth sun gear, the fourth planet carrier, and the fourth ring gear respectively, and the thirteenth, fourteenth, and fifteenth rotational elements may be the fifth sun gear, the fifth planet carrier, and the fifth ring gear respectively.

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

According to an exemplary form of the present disclosure, ten forward speed stages and one reverse speed stage may be achieved by combining five planetary gear sets being simple planetary gear sets with six engaging elements.

In addition, since gear ratio span greater than 9.9 is secured, driving efficiency of the engine may be increased. In addition, since linearity of step ratios can be secured due to multiple speed stages, drivability such as acceleration before and after shift, rhythmical engine speed, and so on may be improved.

In addition, since ten forward speed stages and one reverse speed stages are achieved by using five planetary gear sets but the number of engaging elements is reduced, drag loss of clutches and brakes may be reduced and power delivery efficiency and fuel economy may be improved.

In addition, since a planetary gear set of an output side in torque parallel type is used and torque is evenly shared to each planetary gear set and each engaging element, torque delivery efficiency and durability may be improved.

In addition, since five planetary gear sets are used to achieve ten forward speed stages and one reverse speed stage, flexibility of output gear ratios may be increased and linearity of step ratios may be improved.

Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a planetary gear train according to an exemplary form of the present disclosure; and

FIG. 2 is an operation chart of engaging elements at each speed stage in the planetary gear train according to an exemplary form of the present disclosure.

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

However, parts which are not related with the description are omitted for clearly describing the exemplary form of the present disclosure and like reference numerals refer to like or similar elements throughout the present disclosure.

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 an exemplary form of the present disclosure.

As shown in FIG. 1 , a planetary gear train includes first, second, third, fourth, and fifth planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 disposed on the same axis, an input shaft IS, an output shaft OS, nine shafts TM 1 , TM 2 , TM 3 , TM 4 , TMS, TM 6 , TM 7 , TM 8 , and TM 9 connected to at least one rotation element of the first, second, third, fourth, and fifth planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 , engaging elements including three clutches C 1 , C 3 , and C 3 and three brakes B 1 , B 3 , and B 3 , and a transmission housing H.

Torque input from an engine to the input shaft IS is changed by cooperation of the first, second, third, fourth, and fifth planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 , and the changed torque is output through the output shaft OS.

According to the exemplary form of the present disclosure, the planetary gear sets are disposed in a sequence of the fourth, third, first, second, and fifth planetary gear sets PG 4 , PG 3 , PG 1 , PG 2 , and PG 5 from an engine side.

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

The output shaft OS is an output member, is disposed on the same axis with the input shaft IS, and transmits driving torque to a driving wheel through a differential apparatus.

The first planetary gear set PG 1 is a single pinion planetary gear set and includes a first sun gear S 1 of a first rotation element N 1 , a first planet carrier PC 1 of a second rotation element N 2 rotatably supporting a plurality of first pinion gears P 1 evenly disposed on and externally engaged with an exterior circumference the first sun gear S 1 , and a first ring gear R 1 of a third rotation element N 3 internally engaged with the plurality of first pinion gears P 1 and operably connected with the first sun gear S 1 .

The second planetary gear set PG 2 is a single pinion planetary gear set and includes a second sun gear S 2 of a fourth rotation element N 4 , a second planet carrier PC 2 of a fifth rotation element N 5 rotatably supporting a plurality of second pinion gears P 2 evenly disposed on and externally engaged with an exterior circumference the second sun gear S 2 , and a second ring gear R 2 of a sixth rotation element N 6 internally engaged with the plurality of second pinion gears P 2 and operably connected with the second sun gear S 2 .

The third planetary gear set PG 3 is a single pinion planetary gear set and includes a third sun gear S 3 of a seventh rotation element N 7 , a third planet carrier PC 3 of an eighth rotation element N 8 rotatably supporting a plurality of third pinion gears P 3 evenly disposed on and externally engaged with an exterior circumference the third sun gear S 3 , and a third ring gear R 3 of a ninth rotation element N 9 internally engaged with the plurality of third pinion gears P 3 and operably connected with the third sun gear S 3 .

The fourth planetary gear set PG 4 is a single pinion planetary gear set and includes a fourth sun gear S 4 of a tenth rotation element N 10 , a fourth planet carrier PC 4 of an eleventh rotation element N 11 rotatably supporting a plurality of fourth pinion gears P 4 evenly disposed on and externally engaged with an exterior circumference the fourth sun gear S 4 , and a fourth ring gear R 4 of a twelfth rotation element N 12 internally engaged with the plurality of fourth pinion gears P 4 and operably connected with the fourth sun gear S 4 .

The fifth planetary gear set PG 5 is a single pinion planetary gear set and includes a fifth sun gear S 5 of a thirteenth rotation element N 13 , a fifth planet carrier PC 5 of a fourteenth rotation element N 14 rotatably supporting a plurality of fifth pinion gears P 5 evenly disposed on and externally engaged with an exterior circumference the fifth sun gear S 5 , and a fifth ring gear R 5 of a fifteenth rotation element N 15 internally engaged with the plurality of fifth pinion gears P 5 and operably connected with the fifth sun gear S 5 .

The first rotation element N 1 is directly connected with the fourth rotation element N 4 , the second rotation element N 2 is directly connected with the eighth rotation element N 8 and the fifteenth rotation element N 15 , the fifth rotation element N 5 is directly connected with the thirteenth rotation element N 13 , the seventh rotation element N 7 is directly connected with the tenth rotation element N 10 , and the ninth rotation element N 9 is directly connected with the eleventh rotation element N 11 such that the first, second, third, fourth, and fifth planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 include nine shafts TM 1 , TM 2 , TM 3 , TM 4 , TMS, TM 6 , TM 7 , TM 8 , and TM 9 .

The nine shafts TM 1 to TM 9 will be described in further detail.

The nine shafts TM 1 to TM 9 directly connects a plurality of rotation elements among the rotation elements of the planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 with each other, are rotation members that are connected to any one rotation element and rotate with the any one rotation element to transmit torque, are rotation members that selectively connects any one rotation element with the transmission housing H, or are fixed members that directly connect any one rotation element to the transmission housing H.

The first shaft TM 1 is connected with the third rotation element N 3 (first ring gear R 1 ) and is directly connected with the input shaft IS to be always operated as an input element.

The second shaft TM 2 is connected with the fourteenth rotation element N 14 (fifth planet carrier PC 5 ) and is directly connected with the output shaft OS to be always operated an output element.

The third shaft TM 3 is connected with the fifth rotation element N 5 (second planet carrier PC 2 ) and the thirteenth rotation element N 13 (fifth sun gear S 5 ).

The fourth shaft TM 4 is connected with the second rotation element N 2 (first planet carrier PC 1 ), the eighth rotation element N 8 (third planet carrier PC 3 ), and the fifteenth rotation element N 15 (fifth ring gear R 5 ).

The fifth shaft TM 5 is connected with the ninth rotation element N 9 (third ring gear R 3 ) and the eleventh rotation element N 11 (fourth planet carrier PC 4 ).

The sixth shaft TM 6 is connected with the first rotation element N 1 (first sun gear S 1 ) and the fourth rotation element N 4 (second sun gear S 2 ).

The seventh shaft TM 7 is connected with the sixth rotation element N 6 (second ring gear R 2 ).

The eighth shaft TM 8 is connected with the seventh rotation element N 7 (third sun gear S 3 ) and the tenth rotation element N 10 (fourth sun gear S 4 ).

The ninth shaft TM 9 is connected with the twelfth rotation element N 12 (fourth ring gear R 4 ).

Here, the second shaft TM 2 is selectively connected with the sixth shaft TM 6 , and the fifth shaft TM 5 is selectively connected respectively with the sixth shaft TM 6 and the seventh shaft TM 7 .

In addition, the third shaft TM 3 , the eighth shaft TM 8 , and the ninth shaft TM 9 are selectively connected with the transmission housing H and are operated as selective fixed elements, respectively.

Three clutches C 1 , C 2 , and C 3 that are engaging elements are disposed at portions at which any two shafts among the nine shafts TM 1 to TM 9 including the input shaft IS and the output shaft OS are selectively connected with each other.

In addition, three brakes B 1 , B 2 , and B 3 that are engaging elements are disposed at portions at which any one shaft among the nine shafts TM 1 to TM 9 is selectively connected with the transmission housing H.

Arrangement of the six engaging elements (three clutches C 1 to C 3 and three brakes B 1 to B 3 ) will be described in detail.

The first clutch C 1 is disposed between the second shaft TM 2 and the sixth shaft TM 6 and selectively connects the second shaft TM 2 with the sixth shaft TM 6 .

The second clutch C 2 is disposed between the fifth shaft TM 5 and the sixth shaft TM 6 and selectively connects the fifth shaft TM 5 with the sixth shaft TM 6 .

The third clutch C 3 is disposed between the fifth shaft TM 5 and the seventh shaft TM 7 and selectively connects the fifth shaft TM 5 with the seventh shaft TM 7 .

The first brake B 1 is disposed between the third shaft TM 3 and the transmission housing H and selectively connects the third shaft TM 3 with the transmission housing H to be fixed thereto.

The second brake B 2 is disposed between the eighth shaft TM 8 and the transmission housing H and selectively connects the eighth shaft TM 8 with the transmission housing H to be fixed thereto.

The third brake B 3 is disposed between the ninth shaft TM 9 and the transmission housing H and selectively connects the ninth shaft TM 9 with the transmission housing H to be fixed thereto.

The engaging elements including 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 multi-plates friction elements of wet type that are operated by hydraulic pressure. Multi-plates friction elements of wet type are mainly used as the engaging elements, but dog clutches, electric clutches, or magnetic clutches that can be operated by electric signal from an electric control unit can be used as the engaging elements.

FIG. 2 is an operation chart of engaging elements at each speed stage in the planetary gear train according to an exemplary form of the present disclosure.

Referring to FIG. 2 , three engaging elements among 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 are operated at each speed stage in the planetary gear train.

The third clutch C 3 and the first and second brakes B 1 and B 2 are operated at a first forward speed stage D 1 .

In a state that the fifth shaft TM 5 is connected with the seventh shaft TM 7 by operation of the third clutch C 3 , a torque of the input shaft IS is input into the first shaft TM 1 .

At this state, the third shaft and the eighth shaft TM 3 and TM 8 are operated as the fixed elements by operation of the first and second brakes B 1 and B 2 . Therefore, the torque of the input shaft IS is shifted into the first forward speed stage, and the first forward speed stage is output through the output shaft OS connected with the second shaft TM 2 .

The third clutch C 3 and the first and third brakes B 1 and B 3 are operated at a second forward speed stage D 2 .

In a state that the fifth shaft TM 5 is connected with the seventh shaft TM 7 by operation of the third clutch C 3 , the torque of the input shaft IS is input into the first shaft TM 1 .

At this state, the third shaft and the ninth shaft TM 3 and TM 9 are operated as the fixed elements by operation of the first and third brakes B 1 and B 3 . Therefore, the torque of the input shaft IS is shifted into the second forward speed stage, and the second forward speed stage is output through the output shaft OS connected with the second shaft TM 2 .

The second and third clutches C 2 and C 3 and the first brake B 1 are operated at a third forward speed stage D 3 .

In a state that the fifth shaft TM 5 is connected with the sixth shaft TM 6 by operation of the second clutch C 2 and is connected with the seventh shaft TM 7 by operation of the third clutch C 3 , the torque of the input shaft IS is input into the first shaft TM 1 .

At this state, the third shaft TM 3 is operated as the fixed element by operation of the first brake B 1 . Therefore, the torque of the input shaft IS is shifted into the third forward speed stage, and the third forward speed stage is output through the output shaft OS connected with the second shaft TM 2 .

The second clutch C 2 and the first and third brakes B 1 and B 3 are operated at a fourth forward speed stage D 4 .

In a state that the fifth shaft TM 5 is connected with the sixth shaft TM 6 by operation of the second clutch C 2 , the torque of the input shaft IS is input into the first shaft TM 1 .

At this state, the third shaft and the ninth shaft TM 3 and TM 9 are operated as the fixed elements by operation of the first and third brakes B 1 and B 3 . Therefore, the torque of the input shaft IS is shifted into the fourth forward speed stage, and the fourth forward speed stage is output through the output shaft OS connected with the second shaft TM 2 .

The second and third clutches C 2 and C 3 and the third brake B 3 are operated at a fifth forward speed stage D 5 .

In a state that the fifth shaft TM 5 is connected with the sixth shaft TM 6 by operation of the second clutch C 2 and is connected with the seventh shaft TM 7 by operation of the third clutch C 3 , the torque of the input shaft IS is input into the first shaft TM 1 .

At this state, the ninth shaft TM 9 is operated as the fixed element by operation of the third brake B 3 . Therefore, the torque of the input shaft IS is shifted into the fifth forward speed stage, and the fifth forward speed stage is output through the output shaft OS connected with the second shaft TM 2 .

The first and third clutches C 1 and C 3 and the third brake B 3 are operated at a sixth forward speed stage D 6 .

In a state that the second shaft TM 2 is connected with the sixth shaft TM 6 by operation of the first clutch C 1 and the fifth shaft TM 5 is connected with the seventh shaft TM 7 by operation of the third clutch C 3 , the torque of the input shaft IS is input into the first shaft TM 1 .

At this state, the ninth shaft TM 9 is operated as the fixed element by operation of the third brake B 3 . Therefore, the torque of the input shaft IS is shifted into the sixth forward speed stage, and the sixth forward speed stage is output through the output shaft OS connected with the second shaft TM 2 .

The first, second, and third clutches C 1 , C 2 , and C 3 are operated at a seventh forward speed stage D 7 .

In a state that the second shaft TM 2 is connected with the sixth shaft TM 6 by operation of the first clutch C 1 and the fifth shaft TM 5 is connected with the sixth shaft TM 6 by operation of the second clutch C 2 and is connected with the seventh shaft TM 7 by operation of the third clutch C 3 , the torque of the input shaft IS is input into the first shaft TM 1 .

Therefore, the first, second, third, fourth, and fifth planetary gear set PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 become lock-up states. At this state, if the torque of the input shaft IS is input into the first shaft TM 1 , the torque of the input shaft IS is output through the output shaft OS connected with the second shaft TM 2 without speed change.

The first and third clutches C 1 and C 3 and the second brake B 2 are operated at an eighth forward speed stage D 8 .

In a state that the second shaft TM 2 is connected with the sixth shaft TM 6 by operation of the first clutch C 1 and the fifth shaft TM 5 is connected with the seventh shaft TM 7 by operation of the third clutch C 3 , the torque of the input shaft IS is input into the first shaft TM 1 .

At this state, the eighth shaft TM 8 is operated as the fixed element by operation of the second brake B 2 . Therefore, the torque of the input shaft IS is shifted into the eighth forward speed stage, and the eighth forward speed stage is output through the output shaft OS connected with the second shaft TM 2 .

The second and third clutches C 2 and C 3 and the second brake B 2 are operated at a ninth forward speed stage D 9 .

In a state that the fifth shaft TM 5 is connected with the sixth shaft TM 6 by operation of the second clutch C 2 and is connected with the seventh shaft TM 7 by operation of the third clutch C 3 , the torque of the input shaft IS is input into the first shaft TM 1 .

At this state, the eighth shaft TM 8 is operated as the fixed element by operation of the second brake B 2 . Therefore, the torque of the input shaft IS is shifted into the ninth forward speed stage, and the ninth forward speed stage is output through the output shaft OS connected with the second shaft TM 2 .

The first and second clutches C 1 and C 2 and the second brake B 2 are operated at a tenth forward speed stage D 10 .

In a state that the second shaft TM 2 is connected with the sixth shaft TM 6 by operation of the first clutch C 1 and the fifth shaft TM 5 is connected with the sixth shaft TM 6 by operation of the second clutch C 2 , the torque of the input shaft IS is input into the first shaft TM 1 .

At this state, the eighth shaft TM 8 is operated as the fixed element by operation of the second brake B 2 . Therefore, the torque of the input shaft IS is shifted into the tenth forward speed stage, and the tenth forward speed stage is output through the output shaft OS connected with the second shaft TM 2 .

The third clutch C 3 and the second and third brakes B 2 and B 3 are operated at a reverse speed stage REV.

In a state that the fifth shaft TM 5 is connected with the seventh shaft TM 7 by operation of the third clutch C 3 , the torque of the input shaft IS is input into the first shaft TM 1 .

At this state, the eighth shaft and the ninth shaft TM 8 and TM 9 are operated as the fixed elements by operation of the second and third brakes B 2 and B 3 . Therefore, the torque of the input shaft IS is shifted into the reverse speed stage, and the reverse speed stage is output through the output shaft OS connected with the second shaft TM 2 .

According to the exemplary form of the present disclosure, ten forward speed stages and one reverse speed stage may be achieved by using five planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 and six engaging elements including three clutches C 1 , C 2 , and C 3 and three brakes B 1 , B 2 , and B 3 .

In addition, since gear ratio span greater than 9.9 is secured, driving efficiency of the engine may be increased. In addition, since linearity of step ratios can be secured due to multiple speed stages, drivability such as acceleration before and after shift, rhythmical engine speed, and so on may be improved.

In addition, since ten forward speed stages and one reverse speed stages are achieved by using the reduced number of engaging elements, drag loss of clutches and brakes may be reduced and power delivery efficiency and fuel economy may be improved.

In addition, since a planetary gear set of an output side in torque parallel type is used and torque is evenly shared to each planetary gear set and each engaging element, torque delivery efficiency and durability may be improved.

In addition, since five planetary gear sets are used to achieve ten forward speed stages and one reverse speed stage, flexibility of output gear ratios may be increased and linearity of step ratios may be improved.

While this present disclosure has been described in connection with what is presently considered to be practical exemplary forms, it is to be understood that the present disclosure is not limited to the disclosed forms, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the present disclosure.