Planetary gear train of automatic transmission for vehicle

This application claims priority to and the benefit of Korean Patent Application No. 10-2017-0058315, filed on May 10, 2017, which is incorporated herein by reference in its entirety.

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 efficiency and drivability.

Such an automatic transmission achieving more speed stages is desired to increase power performance and driving efficiency for downsizing of an engine. Particularly, a highly efficient multiple-speed transmission having excellent linearity of step ratios closely relates to drivability of a vehicle (e.g., acceleration before and after gear shifts as well as rhythmical engine speed).

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 are undermined.

Accordingly, development of a planetary gear train which may achieve better efficiency with reduced components may be important in order to increase a fuel efficiency through the multiple-speed transmission.

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

However, we have discovered that since a conventional eight-speed automatic transmission has gear ratio span between 6.5 and 7.5 (gear ratio span is a factor for securing linearity of step ratios), power performance and fuel economy is not great.

In addition, if an eight-speed automatic transmission has gear ratio span larger than 9.0, it is hard to secure linearity of step ratios. Therefore, driving efficiency of an engine and drivability of a vehicle may be deteriorated.

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 has been made in an effort to provide a planetary gear train of an automatic transmission for a vehicle having advantages 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.

The present disclosure provides a planetary gear train of an automatic transmission for a vehicle having further advantages of improving torque delivery efficiency and durability by using a planetary gear set of an output side in torque parallel type and reducing torque shared among each planetary gear set and each engaging element.

In addition, the present disclosure provides a highly efficient planetary gear train for an automatic transmission having further advantages of increasing flexibility of output gear ratios and improving linearity of step ratios by using five planetary gear sets for achieving ten forward speed stages and one reverse speed stage.

In one form of the present disclosure, a planetary gear train of an automatic transmission for a vehicle may include: an input shaft receiving torque from an engine; an output shaft outputting 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 rotation elements; a first shaft connected with the first rotation element and the input shaft; a second shaft connected with the fourteenth rotation element and the output shaft; a third shaft connected with the fifth rotation element, the eleventh rotation element, and the thirteenth rotation element; a fourth shaft connected with the eighth rotation element and the fifteenth rotation element; a fifth shaft connected with the sixth rotation element and the tenth rotation element; a sixth shaft connected with the twelfth rotation element; a seventh shaft connected with the third rotation element, the fourth rotation element, and the seventh rotation element; an eighth shaft connected with the second rotation element; and a ninth shaft connected with the ninth rotation element.

The planetary gear train may further include: six engaging elements selectively connecting, among the nine shaft, any one shaft with another shaft, or a corresponding shaft selected from the nine shaft 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 the corresponding shaft selected from the nine shafts to the transmission housing. In particular, the selected corresponding shaft is not connected with the input shaft or the output shaft.

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

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

In another aspect, the first, second, third, fourth, and fifth planetary gear sets may be disposed in a sequence of the first, second, third, fourth, 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 receiving torque of an engine; an output shaft outputting 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 rotation elements; a first shaft connected with the first rotation element and the input shaft; a second shaft connected with the fourteenth rotation element and the output shaft; a third shaft connected with the fifth rotation element, the eleventh rotation element, and the thirteenth rotation element; a fourth shaft connected with the eighth rotation element and the fifteenth rotation element; a fifth shaft connected with the sixth rotation element and the tenth rotation element; a sixth shaft connected with the twelfth rotation element; and a plurality of shafts configured to selectively and respectively connect a transmission housing to corresponding rotation elements selected from the rotation elements of the first, second, and third planetary gear sets. In particular, the selected corresponding rotation elements are not connected to any of the first to sixth shafts.

The plurality of shafts may include: a seventh shaft connected with the third rotation element, the fourth rotation element, and the seventh rotation element; an eighth shaft connected with the second rotation element; and a ninth shaft connected with the ninth rotation element.

The planetary gear train may further include: three clutches, any one thereof configured to connect any two shafts among the nine shafts; and three brakes, any one thereof configured to selectively connect the transmission housing to a corresponding shaft among the nine shafts, wherein the selected corresponding shaft is not connected with the input shaft or the output shaft.

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

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

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

In another aspect, the first, second, third, fourth, and fifth planetary gear sets may be disposed in a sequence of the first, second, third, fourth, 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 receiving torque of an engine; an output shaft outputting 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 rotation elements; a first shaft connected with the first rotation element and the input shaft; a second shaft connected with the fourteenth rotation element and the output shaft; a third shaft connected with the fifth rotation element, the eleventh rotation element, and the thirteenth rotation element; a fourth shaft connected with the eighth rotation element and the fifteenth rotation element; a fifth shaft connected with the sixth rotation element and the tenth rotation element; a sixth shaft connected with the twelfth rotation element; and seventh, eighth, and ninth shafts configured to selectively and respectively connect, by brakes, a transmission housing to corresponding rotation elements selected from the rotation elements of the first, second, and third planetary gear sets, wherein the corresponding rotation elements are not connected to any one of the first to sixth shafts.

The first shaft and the third shaft, the first shaft and the sixth shaft, and the fourth shaft and the fifth shaft may be selectively and respectively connected with each other through clutches, the seventh shaft is connected with the third rotation element, the fourth rotation element, and the seventh rotation element, the eighth shaft is connected with the second rotation element, and the ninth shaft is connected with the ninth rotation element.

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

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

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

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

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

In addition, since gear ratio span is provided to be greater than 9.3, 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 gear shifts, rhythmical engine speed, and so on may be improved.

In addition, since ten forward speed stages and one reverse speed stage are achieved by using five planetary gear sets with reduced number of engaging elements, drag loss of clutches and brakes may be reduced and thus 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 in a first exemplary form of the present disclosure;

FIG. 2 is an operation chart of engaging elements at each speed stage in the planetary gear train in a first exemplary form of the present disclosure; and

FIG. 3 is a schematic diagram of a planetary gear train in a second 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 forms of the present disclosure and like reference numerals refer to like or similar 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.

Further, as used herein, description of elements being “fixedly” connected or interconnected includes elements that are directly connected, i.e. one element directly connected to another element for rotation therewith.

FIG. 1 is a schematic diagram of a planetary gear train in a first exemplary form of the present disclosure.

Referring to 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 to 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 to C 3 and three brakes B 1 to 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 first exemplary form of the present disclosure, the planetary gear sets are disposed in a sequence of the first, third, second, fourth, and fifth planetary gear sets PG 1 , PG 3 , PG 2 , PG 4 , 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 and disposed on the same axis with the input shaft IS. The output shaft OS 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 (i.e., a first rotation element N 1 ), a first planet carrier PC 1 (i.e., 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 of the first sun gear S 1 , and a first ring gear R 1 (i.e., 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 (i.e., a fourth rotation element N 4 ), a second planet carrier PC 2 (i.e., 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 of the second sun gear S 2 , and a second ring gear R 2 (i.e., 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 (i.e., a seventh rotation element N 7 ), a third planet carrier PC 3 (i.e., 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 of the third sun gear S 3 , and a third ring gear R 3 (i.e., 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 (i.e., a tenth rotation element N 10 ), a fourth planet carrier PC 4 (i.e., 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 of the fourth sun gear S 4 , and a fourth ring gear R 4 (i.e., 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 (i.e., a thirteenth rotation element N 13 ), a fifth planet carrier PC 5 (i.e., 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 of the fifth sun gear S 5 , and a fifth ring gear R 5 (i.e., 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 third rotation element N 3 is directly connected with the fourth rotation element N 4 and the seventh rotation element N 7 , the fifth rotation element N 5 is directly connected with the eleventh rotation element N 11 and the thirteenth rotation element N 13 , the sixth rotation element N 6 is directly connected with the tenth rotation element N 10 , and the eighth rotation element N 8 is directly connected with the fifteenth rotation element N 15 such that the first, second, third, fourth, and fifth planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 operate together through nine shafts TM 1 to 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. The nine shafts may be rotation members that are connected to any one rotation element (i.e., a corresponding rotation element among the rotation elements of the five planetary gear sets) and rotate with the any one rotation element (i.e., the corresponding rotation element) to transmit torque. In another form, the rotation members (i.e., selected shafts from the nine shafts) may selectively connect any one rotation element with the transmission housing H, or some of the nine shafts may be fixed members that directly connect any one rotation element to the transmission housing H.

The first shaft TM 1 is connected, and preferably fixedly connected, with the first rotation element N 1 (first sun gear S 1 ) and is directly connected with the input shaft IS so as to be continuously operated as an input element.

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

The third shaft TM 3 is connected, and preferably fixedly connected, with the fifth rotation element N 5 (second planet carrier PC 2 ), the eleventh rotation element N 11 (fourth planet carrier PC 4 ), and the thirteenth rotation element N 13 (fifth sun gear S 5 ).

The fourth shaft TM 4 is connected, and preferably fixedly connected, with 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, and preferably fixedly connected, with the sixth rotation element N 6 (second ring gear R 2 ) and the tenth rotation element N 10 (fourth sun gear S 4 ).

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

The seventh shaft TM 7 is connected, and preferably fixedly connected, with the third rotation element N 3 (first ring gear R 1 ), the fourth rotation element N 4 (second sun gear S 2 ), and the seventh rotation element N 7 (third sun gear S 3 ).

The eighth shaft TM 8 is connected, and preferably fixedly connected, with the second rotation element N 2 (first planet carrier PC 1 ).

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

Here, the fourth shaft TM 4 is selectively connected with the fifth shaft TM 5 , and the third shaft TM 3 and the sixth shaft TM 6 are selectively and respectively connected with the first shaft TM 1 .

In addition, each of the seventh shaft TM 7 , the eighth shaft TM 8 , and the ninth shaft TM 9 is selectively connected with the transmission housing H to be operated as a selective fixed element.

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 first shaft TM 1 and the third shaft TM 3 and selectively connects the first shaft TM 1 with the third shaft TM 3 .

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

The third clutch C 3 is disposed between the fourth shaft TM 4 and the fifth shaft TM 5 and selectively connects the fourth shaft TM 4 with the fifth shaft TM 5 .

The first brake B 1 is disposed between the seventh shaft TM 7 and the transmission housing H and selectively connects and fixes the seventh shaft TM 7 to the transmission housing H.

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

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

Referring to FIG. 1 , the first clutch C 1 selectively connects the first shaft TM 1 to the third shaft TM 3 , and the second clutch C 2 selectively connects the sixth shaft TM 6 to the first shaft TM 1 . Since the first shaft TM 1 is continuously connected with the input shaft IS, the first clutch C 1 may be configured to selectively connect the input shaft IS with the third shaft TM 3 , and the second clutch C 2 may be configured to selectively connect the input shaft IS with the sixth shaft TM 6 .

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 a first 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 according to the first exemplary form of the present disclosure.

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

In a state that the first shaft TM 1 is connected with the third shaft TM 3 by operation of the first clutch C 1 , torque of the input shaft IS is input to the first and third shafts TM 1 and TM 3 .

At this state, the eighth and ninth shafts 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 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 second clutch C 2 and the second and third brakes B 2 and B 3 are operated at a second forward speed stage D 2 .

In a state that the first shaft TM 1 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 to the first and sixth shafts TM 1 and TM 6 .

At this state, the eighth and ninth shafts 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 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 clutch C 2 and the first and third brakes B 1 and B 3 are operated at a third forward speed stage D 3 .

In a state that the first shaft TM 1 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 to the first and sixth shafts TM 1 and TM 6 .

At this state, the seventh and ninth shafts TM 7 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 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 first and second clutches C 1 and C 2 and the third brake B 3 are operated at a fourth forward speed stage D 4 .

In a state that the first shaft TM 1 is connected with the third shaft TM 3 by operation of the first clutch C 1 and the first shaft TM 1 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 to the first, third, and sixth shafts TM 1 , TM 3 , and TM 6 .

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 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 first shaft TM 1 is connected with the sixth shaft TM 6 by operation of the second clutch C 2 and the fourth shaft TM 4 is connected with the fifth shaft TM 5 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the first and sixth shafts TM 1 and TM 6 .

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 first shaft TM 1 is connected with the third shaft TM 3 by operation of the first clutch C 1 and the fourth shaft TM 4 is connected with the fifth shaft TM 5 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the first and third shafts TM 1 and TM 3 .

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 first shaft TM 1 is connected with the third shaft TM 3 by operation of the first clutch C 1 , the first shaft TM 1 is connected with the sixth shaft TM 6 by operation of the second clutch C 2 , and the fourth shaft TM 4 is connected with the fifth shaft TM 5 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the first, third, and sixth shafts TM 1 , TM 3 , and TM 6 .

In this case, the first, second, third, fourth, and fifth planetary gear sets PG 1 , PG 2 , PG 3 , PG 4 , and PG 5 become lock-up states. Therefore, 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 first brake B 1 are operated at an eighth forward speed stage D 8 .

In a state that the first shaft TM 1 is connected with the third shaft TM 3 by operation of the first clutch C 1 and the fourth shaft TM 4 is connected with the fifth shaft TM 5 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the first and third shafts TM 1 and TM 3 .

At this state, the seventh shaft TM 7 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 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 first brake B 1 are operated at a ninth forward speed stage D 9 .

In a state that the first shaft TM 1 is connected with the sixth shaft TM 6 by operation of the second clutch C 2 and the fourth shaft TM 4 is connected with the fifth shaft TM 5 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the first and sixth shafts TM 1 and TM 6 .

At this state, the seventh shaft TM 7 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 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 second and third clutches C 2 and C 3 and the second brake B 2 are operated at a tenth forward speed stage D 10 .

In a state that the first shaft TM 1 is connected with the sixth shaft TM 6 by operation of the second clutch C 2 and the fourth shaft TM 4 is connected with the fifth shaft TM 5 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the first and sixth shafts TM 1 and TM 6 .

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 fourth shaft TM 4 is connected with the fifth shaft TM 5 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the first shaft TM 1 .

At this state, the eighth and ninth shafts 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 as inverse rotation speed.

FIG. 3 is a schematic diagram of a planetary gear train in a second exemplary form of the present disclosure.

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

The arrangement of the planetary gear sets according to the second exemplary form differs from that according to the first exemplary form, but connections of the nine shafts TM 1 to TM 9 , three clutches C 1 to C 2 , and the three brakes B 1 to B 3 according to the second exemplary form are the same as those according to the first exemplary form. Therefore, operations and effects of the planetary gear train according to the second exemplary form are the same as those according to the first exemplary form.

According to the first and second exemplary forms 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 9.3 is secured, driving efficiency of the engine may be improved. In addition, since linearity of step ratios can be secured due to multiple speed stages, drivability such as acceleration before and after gear shifts, rhythmical engine speed, and so on may be improved.

In addition, since ten forward speed stages and one reverse speed stage are achieved by using the reduced number of engaging elements, drag loss caused by clutches and brakes may be reduced and thus 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.

PG 1 , PG 2 , PG 3 , PG 4 , PG 5 : first, second, third, fourth, and fifth planetary gear sets

S 1 , S 2 , S 3 , S 4 , S 5 : first, second, third, fourth, and fifth sun gears

PC 1 , PC 2 , PC 3 , PC 4 , PC 5 : first, second, third, fourth, and fifth planet carriers

R 1 , R 2 , R 3 , R 4 , R 5 : first, second, third, fourth, and fifth ring gears

C 1 , C 2 , C 3 : first, second, and third clutches

B 1 , B 2 , B 3 : first, second, and third brakes

IS: input shaft

OS: output shaft

TM 1 , TM 2 , TM 3 , TM 4 , TM 5 , TM 6 , TM 7 , TM 8 , TM 9 : first, second, third, fourth, fifth, sixth, seventh, eighth, and ninth shafts