Twin clutch transmission
A twin clutch transmission for a large horsepower vehicle having a compact size and a high transmission efficiency is obtained. In a twin clutch transmission, there are provided an input shaft, an odd-numbered level speed change mechanism 30 , an even-numbered level speed change mechanism 60 , a synchronizing speed change mechanism 100 , and an output mechanism 90 . The speed change mechanisms 30 and 60 include transmission gear trains 32 and 62 , main clutches 34 and 64 for selectively transmitting the powers of the transmission gear trains 32 and 62 to the transmission shafts 40 and 70 . The synchronizing speed change mechanism 100 includes synchronizing gear trains 110 and 120 for coupling the rotation of the odd-numbered level transmission shaft 32 with the rotation of the even-numbered level transmission shaft 62 , and synchronizing clutches 112 and 122 for selecting coupling by this synchronizing gear train.
1. A twin clutch transmission comprising:
an input shaft to which a power of an engine is inputted;
an output shaft from which at least a rotation in a first direction is outputted;
an odd-numbered level speed change mechanism to which a rotation of the input shaft is transmitted, the odd-numbered level speed change mechanism performing a speed change of an odd-numbered level when the output shaft is rotated in the first direction;
an even-numbered level speed change mechanism to which a rotation of the input shaft is transmitted, the even-numbered level speed change mechanism performing a speed change of an even-numbered level when the output shaft is rotated in the first direction;
a synchronizing speed change mechanism for synchronizing the odd-numbered level speed change mechanism and the even-numbered level speed change mechanism at a time of a speed change; and
an output mechanism for transmitting powers of the odd-numbered level speed change mechanism and the even-numbered level speed change mechanism to the output shaft, wherein:
the odd-numbered level speed change mechanism includes
an odd-numbered level transmission shaft,
an odd-numbered level transmission gear train placed between the input shaft and the odd-numbered level transmission shaft,
an odd-numbered level main clutch for selectively transmitting a rotation of the input shaft to the odd-numbered level transmission shaft via the odd-numbered level transmission gear train,
an odd-numbered level speed-changing gear train provided on the odd-numbered level transmission shaft, the odd-numbered level speed-changing gear train transmitting the rotation to the output mechanism, and
an odd-numbered level mechanical clutch for selectively coupling the odd-numbered level speed-changing gear train with the odd-numbered level transmission shaft;
the even-numbered level speed change mechanism includes
an even-numbered level transmission shaft,
an even-numbered level transmission gear train placed between the input shaft and the even-numbered level transmission shaft,
an even-numbered level main clutch for selectively transmitting a rotation of the input shaft to the even-numbered level transmission shaft via the even-numbered level transmission gear train,
an even-numbered level speed-changing gear train provided on the even-numbered level transmission shaft, the even-numbered level speed-changing gear train transmitting the rotation to the output mechanism, and
an even-numbered level mechanical clutch for selectively coupling the even-numbered level speed-changing gear train with the even-numbered level transmission shaft; and
the synchronizing speed change mechanism includes
a synchronizing gear train for coupling a rotation of the odd-numbered level transmission shaft with that of the even-numbered level transmission shaft, and
a synchronizing clutch for selecting coupling by the synchronizing gear train.
2. The twin clutch transmission according to claim 1 , wherein interlevel ratios between adjacent speed levels are set to be approximately constant.
3. The twin clutch transmission according to claim 2 , wherein gear ratios of the odd-numbered level transmission gear train and the even-numbered level transmission gear train are set so that a rotation ratio of the even-numbered level transmission shaft with respect to the odd-numbered level transmission shaft becomes approximately equal to the interlevel ratio.
4. The twin clutch transmission according to claim 3 , wherein gear ratios of the odd-numbered level speed-changing gear train and the even-numbered level speed-changing gear train are approximately equal to each other between at least a part of adjacent speed change levels, and a gear of the output mechanism is shared between the odd-numbered level speed-changing gear train and the even-numbered level speed-changing gear train.
5. The twin clutch transmission according to claim 1 , wherein:
the synchronizing speed change mechanism includes
a first synchronizing gear train for coupling the odd-numbered level transmission shaft and the even-numbered level transmission shaft so as to achieve a first rotation ratio therebetween,
a first synchronizing clutch for selecting coupling by the first synchronizing gear train,
a second synchronizing gear train for coupling the odd-numbered level transmission shaft and the even-numbered level transmission shaft so as to achieve a second rotation ratio therebetween, and
a second synchronizing clutch for selecting coupling by the second synchronizing gear train; and
a shift-up or a shift-down is performed while achieving synchronization between the odd-numbered level speed change mechanism and the even-numbered level speed change mechanism by selectively coupling the first synchronizing gear train and the second synchronizing gear train.
6. The twin clutch transmission according to claim 5 , wherein the first rotation ratio of the first synchronizing gear train is approximately 1, and the second rotation ratio of the second synchronizing gear train is approximately equal to a square of an interlevel ratio between adjacent speed levels.
7. The twin clutch transmission according to claim 1 , wherein the output mechanism includes a forward/reverse switching mechanical clutch for switching between a forward rotation and a reverse rotation of the output shaft.
8. The twin clutch transmission according to claim 1 , wherein a forward/reverse switching mechanical clutch for switching between a forward rotation and a reverse rotation of the output shaft is provided on the input shaft.
9. The twin clutch transmission according to claim 1 , wherein:
the odd-numbered level speed change mechanism includes
an odd-numbered level reverse rotation idler shaft placed between the input shaft and the odd-numbered level transmission shaft,
an odd-numbered level reverse rotation transmission gear train placed between the input shaft, the reverse rotation idler shaft, and the odd-numbered level transmission shaft,
an odd-numbered level main clutch for coupling the input shaft and the odd-numbered level transmission gear train,
an odd-numbered level reverse rotation main clutch for coupling the input shaft and the odd-numbered level reverse rotation transmission gear train, and
an odd-numbered level forward/reverse switching mechanical clutch provided on the odd-numbered level transmission shaft, the odd-numbered level forward/reverse switching mechanical clutch selecting any one of the odd-numbered level transmission gear train and the odd-numbered level reverse rotation transmission gear train and coupling it with the odd-numbered level transmission shaft;
the even-numbered level speed change mechanism includes
an even-numbered level reverse rotation idler shaft placed between the input shaft and the even-numbered level transmission shaft,
an even-numbered level reverse rotation transmission gear train placed between the input shaft, the reverse rotation idler shaft, and the even-numbered level transmission shaft,
an even-numbered level main clutch for coupling the input shaft and the even-numbered level transmission gear train,
an even-numbered level reverse rotation main clutch for coupling the input shaft and the even-numbered level reverse rotation transmission gear train, and
an even-numbered level forward/reverse switching mechanical clutch provided on the even-numbered level transmission shaft, the even-numbered level forward/reverse switching mechanical clutch selecting any one of the even-numbered level transmission gear train and the even-numbered level reverse rotation transmission gear train and coupling it with the even-numbered level transmission shaft;
when the output shaft is rotated in the first direction,
a rotation of the input shaft is transmitted in the odd-numbered level speed change mechanism to the odd-numbered level transmission shaft through the odd-numbered level main clutch, the odd-numbered level transmission gear train, and the odd-numbered level forward/reverse switching mechanical clutch, and
a rotation of the input shaft is transmitted in the even-numbered level speed change mechanism to the even-numbered level transmission shaft through the even-numbered level main clutch, the even-numbered level transmission gear train, and the even-numbered level forward/reverse switching mechanical clutch; and
when the output shaft is rotated in a second direction opposite to the rotation in the first direction,
a rotation of the input shaft is transmitted in the odd-numbered level speed change mechanism to the odd-numbered level transmission shaft through the odd-numbered level reverse rotation main clutch, the odd-numbered level reverse rotation transmission gear train, and the odd-numbered level forward/reverse switching mechanical clutch, and
a rotation of the input shaft is transmitted in the even-numbered level speed change mechanism to the even-numbered level transmission shaft through the even-numbered level reverse rotation main clutch, the even-numbered level reverse rotation transmission gear train, and the even-numbered level forward/reverse switching mechanical clutch.
10. The twin clutch transmission according to claim 9 , wherein:
in the odd-numbered level speed change mechanism,
an input shaft side gear in the odd-numbered level reverse rotation transmission gear train is shared with an input shaft side gear in the even-numbered level transmission gear train, and
the odd-numbered level reverse rotation main clutch is shared with the even-numbered level main clutch;
in the even-numbered level speed change mechanism,
an input shaft side gear in the even-numbered level reverse rotation transmission gear train is shared with an input shaft side gear in the odd-numbered level transmission gear train, and
the even-numbered level reverse rotation main clutch is shared with the odd-numbered level main clutch; and
when the output shaft is rotated in the second direction,
a rotation of the input shaft is transmitted in the odd-numbered level speed change mechanism to the odd-numbered level transmission shaft through the even-numbered level main clutch, the odd-numbered level reverse rotation transmission gear train, and the odd-numbered level forward/reverse switching mechanical clutch, and
a rotation of the input shaft is transmitted in the even-numbered level speed change mechanism to the even-numbered level transmission shaft through the odd-numbered level main clutch, the even-numbered level reverse rotation transmission gear train, and the even-numbered level forward/reverse switching mechanical clutch.
11. The twin clutch transmission according to claim 9 or 10 , wherein:
gear ratios of the odd-numbered level reverse rotation transmission gear train and the even-numbered level transmission gear train are approximately equal to each other and gear ratios of the even-numbered level reverse rotation transmission gear train and the odd-numbered level transmission gear train are approximately equal to each other; and
when the output shaft is rotated in the second direction,
the odd-numbered level speed change mechanism performs a speed change of an even-numbered level and the even-numbered level speed change mechanism performs a speed change of an odd-numbered level.
12. The twin clutch transmission according to claim 9 , wherein
the synchronizing speed change mechanism includes:
a first synchronizing gear train for coupling the odd-numbered level transmission shaft and the even-numbered level transmission shaft so as to obtain a first rotation ratio therebetween;
a first synchronizing clutch for selecting coupling by the first synchronizing gear train;
a second synchronizing gear train for coupling the odd-numbered level transmission shaft and the even-numbered level transmission shaft so as to obtain a second rotation ratio therebetween;
a second synchronizing clutch for selecting coupling by the second synchronizing gear train;
a third synchronizing gear train for coupling the odd-numbered level transmission shaft and the even-numbered level transmission shaft so as to obtain a third rotation ratio therebetween; and
a third synchronizing clutch for selecting coupling by the third synchronizing gear train.
13. The twin clutch transmission according to claim 12 , wherein:
in the synchronizing speed change mechanism the first rotation ratio is approximately 1, the second rotation ratio is approximately equal to a square of an interlevel ratio between adjacent speed levels, and the third rotation ratio is approximately equal to an inverse of the square of the interlevel ratio;
when the output shaft is rotated in the first direction, a shift-up or a shift-down is performed while achieving synchronization between the odd-numbered level speed change mechanism and the even-numbered level speed change mechanism by selectively coupling the first synchronizing gear train with the second synchronizing gear train; and
when the output shaft is rotated in the second direction, a shift-up or a shift-down is performed while achieving synchronization between the odd-numbered level speed change mechanism and the even-numbered level speed change mechanism by selectively coupling the first synchronizing gear train with the third synchronizing gear train.