JP2010144775A - Multistage transmission - Google Patents

Abstract

A gear having a greater number of stages than the number of gear trains can be achieved without increasing the shaft length of the transmission.
A transmission includes a first input shaft 11 for fixing drive gears G1a and G3a, a second input shaft 12 for fixing drive gears G2a and G4a, and power of a drive source to the input shafts 11 and 12. Free first or second clutch C1, C2, first intermediate shaft 31 supporting driven gears G1b, G3b, second intermediate shaft 32 supporting driven gears G2b, G4b, first or second A first synchronous meshing mechanism SM1 that selectively establishes gear trains G1 and G3, a second synchronous meshing mechanism SM2 that selectively establishes second or fourth gear trains G2 and G4, and a double pinion type planetary gear 5; A third clutch C3 that can freely connect the ring gear Ri of the planetary gear 5 and the carrier Ca, the first intermediate shaft 31 to the carrier Ca, the second intermediate shaft 32 to the sun gear Sa, and the output gear 6 to the ring gear Ri. Linking That.
[Selection] Figure 1

Description

  The present invention relates to a multi-stage transmission in which a plurality of gear trains having different gear ratios are interposed between an input shaft rotated by power of a drive source and an output member.

  Conventionally, as this type of transmission, first and second intermediate shafts connected to the input shaft via first and second separate clutches are arranged on the same axis as the input shaft. In addition, the first and second output shafts connected to the output member are arranged, the drive gear of the odd-numbered gear train in the gear ratio order is fixed to the first intermediate shaft, and the gear ratio is fixed to the second intermediate shaft. Drive gears of even-numbered gear trains are fixed in order, driven gears that mesh with drive gears of a plurality of low-speed gear trains are supported on the first output shaft, and a plurality of high-speed gears are supported on the second output shaft. Driven gears that mesh with the drive gears of the row are pivotally supported, and the driven gears on the first and second output shafts are selectively connected to the output shafts via a synchronous meshing mechanism, A so-called dual clutch transmission (DCT) is known (see, for example, Patent Document 1).

  In this case, when power is transmitted through the odd-numbered gear train in the gear ratio order (the first clutch is engaged and the second clutch is released at this time), the driven gear of the even-numbered gear train is used. Can be coupled to the corresponding output shaft via a synchronous meshing mechanism. Therefore, by releasing the first clutch and engaging the second clutch at the time of shifting, it is possible to switch to a power transmission state via the even-numbered gear train with good responsiveness. Similarly, when the power is transmitted through the even-numbered gear train in the gear ratio order, the driven gear of the odd-numbered gear train is connected to the corresponding output shaft via the synchronous meshing mechanism, and the second clutch is used during the gear shifting. By disengaging and engaging the first clutch, it is possible to switch to the power transmission state via the odd-numbered gear train with good responsiveness.

By the way, recently, it is desired to increase the number of shift stages of the transmission in order to improve fuel efficiency. Here, the above conventional example requires as many gear trains as the number of gears. Further, the shaft length of the transmission cannot be increased so much in terms of in-vehicle space. For this reason, in order to increase the number of shift stages, it is necessary to reduce the gear width of each gear train and to secure an arrangement space for the increased gear train. However, if the gear width is reduced, the gear strength is reduced, so it is difficult to increase the number of shift stages without increasing the shaft length of the transmission.
JP 2005-172220 A

  In view of the above points, the present invention is capable of performing gear shifting with a number of gears greater than the number of gear trains, and suppresses the extension of the shaft length, the increase in the number of shafts, and the expansion of the outer shape, thereby reducing the gear number An object of the present invention is to provide a multi-stage transmission that can be increased.

  In order to achieve the above-described object, the present invention provides a multi-stage that changes the rotational speed of an input shaft rotated by the power of a drive source to a plurality of stages via a plurality of gear trains having different speed ratios and outputs the result from an output member. A first input shaft that fixes or pivotally supports the drive gears of the odd-numbered gear trains in the gear ratio order, and fixed or pivotally supports the drive gears of the even-numbered gear trains in the gear ratio order. A second input shaft; a first friction engagement mechanism for releasably transmitting the power of the drive source to the first input shaft; and a second friction engagement mechanism for releasably transmitting the power of the drive source to the second input shaft. A first intermediate shaft that pivotally supports or fixes a driven gear that meshes with the drive gear of each odd-numbered gear train in the gear ratio order, and a driven gear that meshes with the drive gear of each even-numbered gear train in the gear ratio order. A second intermediate shaft for supporting or fixing the shaft, and a drive gear of each odd-numbered gear train in the gear ratio order A first synchronous mesh that selectively establishes one of the odd-numbered gear trains in the gear ratio order by connecting a gear supported by the first input shaft or the first intermediate shaft of the driven gear to the shaft. A mechanism and a gear supported by the second input shaft or the second intermediate shaft among the drive gear and the driven gear of each even-numbered gear train in the gear ratio order are connected to the shaft, and the even number in the gear ratio order. A second synchronous mesh mechanism that selectively establishes one of the second gear trains, and first, second, and third rotational elements that are rotatable relative to each other, the first rotational element and the second rotational element A differential mechanism configured to rotate at a speed between the rotation speed of the first rotation element and the rotation speed of the second rotation element when the third rotation element rotates at a different speed; A third friction engagement mechanism that connects two of the three rotation elements, and the first rotation element of the differential mechanism and the first rotation element Respectively a first intermediate shaft and the second intermediate shaft is coupled to a rotating element, wherein the third rotating element of the differential mechanism is connected to the output member.

  According to the present invention, for example, when the first friction engagement mechanism is engaged and the first first gear train positioned at the lowest speed in the gear ratio order is established, the first rotation element outputs the output speed of the first gear train. In this state, the third friction engagement mechanism is engaged, whereby the third rotation element rotates at the same speed as the first rotation element, and power transmission at the first speed stage is performed. When the engagement of the third friction engagement mechanism is released from this state and the second second gear train is established in the gear ratio order, the second rotation element rotates at the output speed of the second gear train. Here, since the first rotating element rotates at the output speed of the first gear train, the third rotating element rotates at a speed between the output speed of the first gear train and the output speed of the second gear train. In other words, power transmission at the second gear is performed. Thus, since the third rotation element can be rotated at a speed between the output speed of the odd-numbered gear train and the output speed of the even-numbered gear train, N is the total number of gear trains (2N− 1) A step shift can be performed.

  Here, in the present invention, a differential mechanism and a third friction engagement mechanism are required, but the number of shift stages can be dramatically increased as compared with the number of shift gear trains as described above. Therefore, it is possible to increase the number of shift stages without increasing the shaft length, the number of axes, and the outer shape of the transmission as compared with the conventional multi-stage transmission.

  Further, in the present invention, one of the drive gear and the driven gear of the gear train excluding the lowest gear and the fastest gear train is set to the gear stage established only by the gear train and the two gears adjacent in the gear ratio order. It can remain connected to the corresponding shaft for a total of three speeds of the two speeds established by the combination with the train, and the drive and driven gears of the lowest and fastest gear trains. One of the gears may remain connected to the corresponding shaft over two gear stages of one gear stage established by a combination of the corresponding gear stage and one gear train adjacent in the gear ratio ratio of the gear stage. it can. Therefore, the number of intermittent engagement of the synchronous meshing mechanism is greatly reduced, and the consumption of the synchronous meshing mechanism can be remarkably reduced.

  Further, in the conventional dual clutch transmission (DCT), when the two-speed shift is performed, the friction engagement mechanism cannot be switched, and it is necessary to switch the engagement state of the synchronous meshing mechanism. It cannot be switched smoothly. For this reason, in the case of performing the two-speed shift with the conventional DCT, the responsiveness is lowered, so that it is difficult to realize. According to the present invention, at the shift speed at which the third friction engagement mechanism is engaged, the two-speed shift is performed only by switching the engagement between the first friction engagement mechanism and the second friction engagement mechanism. Can do. For this reason, the two-speed shift can be performed with good responsiveness.

  In the present invention, it is desirable that the first intermediate shaft and the second intermediate shaft are disposed on the same axis as the differential mechanism. According to this, since the first intermediate shaft and the second intermediate shaft are disposed on the same axis, the outer diameter in the radial direction of the transmission can be reduced and the size can be reduced. In addition, gears for connecting the first and second intermediate shafts to the first and second rotating elements of the differential are not necessary, and the number of parts can be reduced to reduce costs and weight. it can.

  In the present invention, an idle shaft disposed in parallel with the first and second input shafts, a first idle gear that is pivotally supported or fixed to the idle shaft and meshes with a drive gear of any gear train, A second idle gear fixed to the shaft or pivotally supported and meshed with the driven gear of any gear train; and a third synchronous mesh mechanism for releasably coupling the idle gear pivotally supported by the idle shaft to the idle shaft. It is desirable to provide According to this, if the idle gear supported by the idle shaft is connected to the idle shaft by the third synchronous meshing mechanism, the rotation of the first input shaft or the second input shaft is performed via the idle shaft through the first intermediate shaft. The shaft or the second intermediate shaft can reversely rotate to establish a reverse gear.

  Here, as the differential mechanism of the present invention, for example, it is conceivable to use a planetary gear composed of a sun gear, a carrier, and a ring gear. However, the outer diameter of the differential mechanism becomes large, and other vehicle parts such as a differential gear. It is also possible to interfere with. In this case, the differential mechanism meshes with the first sun gear, which is the first rotating element connected to the first intermediate shaft, and the second sun gear, which is the second rotating element connected to the second intermediate shaft. The first sun gear is composed of a planetary gear comprising a carrier that is a third rotating element that supports a pair of pinions meshed with the second sun gear so as to rotate and revolve freely, and the third friction engagement mechanism is formed between the carrier and the first intermediate gear. If the shaft or the second intermediate shaft is configured to be releasably connected, the pair of pinions can be meshed in the circumferential direction, thereby reducing the outer diameter of the differential mechanism by the amount of the ring gear and one pinion. It can be made small, and interference with other members in the radial direction of the differential mechanism can be suppressed.

  Further, when a planetary gear is used as the differential mechanism of the present invention, for example, by providing a fourth friction engagement mechanism that can fix the second rotating element connected to the second intermediate shaft to the transmission case, for example, By engaging the fourth friction engagement mechanism and establishing the first first gear train that is positioned at the lowest speed in the gear ratio order, a gear position that is lower than the gear ratio of the first gear train is established. The total number of gear trains is N, and (2N) speed shifts can be performed.

  FIG. 1 shows a multi-stage transmission according to a first embodiment of the present invention. The transmission includes a first input shaft 11, a hollow second input shaft 12 that is disposed on the same axis line as the first input shaft 11 and in which the first input shaft 11 is inserted, and a transmission gear ratio (driven gear). The first input shaft 11 can freely release the rotation of the first to fourth four gear trains G1 to G4 having different number of teeth / number of teeth of the drive gear and the drive wheel 2 (flywheel) of the engine as the drive source. A first clutch C1 as a first friction engagement mechanism for transmission and a second clutch C2 as a second friction engagement mechanism for releasably transmitting the rotation of the flywheel 2 to the second input shaft 12 are provided.

  The drive gears G1a, G3a of the odd-numbered gear trains G1, G3 in the gear ratio order are fixed to the first input shaft 11. The drive gears G2a, G4a of the even-numbered gear trains G2, G4 in the gear ratio order are fixed to the second input shaft 12. The first and second intermediate shafts 31 and 32 are provided, and the driven gears G1b and G3b that mesh with the drive gears G1a and G3a of the odd-numbered gear trains G1 and G3 in the gear ratio order are connected to the first intermediate shaft 31. The driven gears G2b and G4b that mesh with the drive gears G2a and G4a of the even-numbered gear trains G2 and G4 in the gear ratio order are supported on the second intermediate shaft 32. Then, on the first intermediate shaft 31, a first synchronous mesh mechanism SM1 (synchronized gear) that selectively connects the driven gear G1b of the first gear train G1 and the driven gear G3b of the third gear train G3 to the first intermediate shaft 31. A mesh mechanism) and a second intermediate shaft 32 that selectively connects the driven gear G2b of the second gear train G2 and the driven gear G4b of the fourth gear train G4 to the second intermediate shaft 32. A synchronous meshing mechanism SM2 is provided.

  Each of the synchronous mesh mechanisms SM1 and SM2 is provided with synchronous sleeves 41 and 42 that are prevented from rotating by the intermediate shafts 31 and 32 and are movable in the axial direction by an actuator (not shown). Then, the driven gear G1b or the driven gear G3b is connected to the first intermediate shaft 31 by moving the synchronous sleeve 41 of the first synchronous mesh mechanism SM1 from the illustrated neutral position NT to the driven gear G1b side or the driven gear G3b side. The first gear train G1 or the third gear train G3 is selectively established. Similarly, the driven gear G2b or the driven gear G4b is connected to the second intermediate shaft 32 by moving the synchronous sleeve 42 of the second synchronous meshing mechanism SM2 from the illustrated neutral position NT to the driven gear G2b side or the driven gear G4b side. Then, the second gear train G2 or the fourth gear train G4 is selectively established. The establishment of the gear train means that power is transmitted from the input shafts 11 and 12 to the corresponding intermediate shafts 31 and 32 via the gear trains G1 to G4.

  The transmission also includes a planetary gear 5 that is a differential mechanism. This planetary gear 5 is a double gear comprising a sun gear Sa, a ring gear Ri, and a carrier Ca that supports a pair of pinions Pi1 and Pi2 that are meshed with each other and one meshed with the sun gear Sa and the other meshed with the ring gear Ri. Consists of a pinion type planetary gear. As an example, when the gear ratio of the planetary gear 5 (the number of teeth of the ring gear Ri / the number of teeth of the sun gear Sa) is set to “2.0”, the ring gear Ri is intermediate between the rotational speed of the sun gear Sa and the rotational speed of the carrier Ca. Rotates at a speed (1/2 of the total rotational speed).

  The first intermediate shaft 31 is formed hollow and the second intermediate shaft 32 is inserted, and both the intermediate shafts 31 and 32 are arranged on the same axis. The first intermediate shaft 31 and the second intermediate shaft 32 are arranged on the same axis as the planetary gear 5. The first intermediate shaft 31 is connected to the carrier Ca, the second intermediate shaft 32 is connected to the sun gear Sa, and the output gear 6 that is an output member is connected to the ring gear Ri. That is, in the first embodiment, the carrier Ca is the first rotation element, the sun gear Sa is the second rotation element, and the ring gear Ri is the third rotation element. The rotation of the output gear 6 is transmitted to the left and right drive wheels of the vehicle via a differential gear (not shown). The sun gear Sa may be connected to the first intermediate shaft 31, and the second intermediate shaft 32 may be connected to the carrier Ca. In this case, the sun gear Sa is the first rotating element, and the carrier Ca is the second rotating element.

  Further, the ring gear Ri of the planetary gear 5 and the carrier Ca are freely connectable by a third clutch C3 as a third friction engagement mechanism. When the third clutch C3 is engaged to connect the ring gear Ri and the carrier Ca, the rotating elements of the planetary gear 5 are locked so that they cannot be rotated relative to each other, and the three rotating elements rotate at a constant speed. The third clutch C3 may be configured such that the ring gear Ri and the sun gear Sa or the carrier Ca and the sun gear Sa can be connected.

  Further, the transmission of the first embodiment is provided with a first brake B1 as a fourth friction engagement mechanism capable of fixing the sun gear Sa as the second rotation element to the transmission case 7. Further, the transmission is provided with a first idle gear GR1 that is supported by an idle shaft 8 parallel to the input shafts 11 and 12, and meshes with the drive gear G2a of the second gear train G2. The first idle gear GR1 is set to have the same number of teeth as (or in the vicinity of) the second drive gear G2a. Further, a second idle gear GR2 that meshes with the driven gear G1b of the first gear train G1 is fixed to the idle shaft 8. The second idle gear GR2 is set to the same number of teeth as (or the vicinity of) the first drive gear G1a. The idle shaft 8 is provided with a third synchronous meshing mechanism SM3 that connects the first idle gear GR1 to the idle shaft 8.

  The third synchromesh mechanism SM3 is provided with a synchronizer sleeve 43 that is prevented from rotating around the idle shaft 8 and is movable in the axial direction by an actuator (not shown). The synchronizer sleeve 43 of the third synchromesh mechanism SM3 is moved from the neutral position NT shown in the figure. The first idle gear GR1 is connected to the idle shaft 8 by moving to the first idle gear GR1 side.

  Next, the shifting operation of the transmission according to the first embodiment will be described with reference to FIG. First, at the time of start, the driven gear G1b of the first gear train G1 is connected to the first intermediate shaft 31 by the first synchronous meshing mechanism SM1 to establish the first gear train G1 and the first brake B1 is engaged. Thus, the sun gear Sa of the planetary gear 5 is fixed to the transmission case 7, and the engaging force of the first clutch C1 is gradually increased.

  At this time, the rotational speed of the carrier Ca is equal to the output speed of the first gear train G1, the rotational speed of the sun gear Sa is zero, and the ring gear Ri is increased as the engagement force of the first clutch C1 increases. The rotational speed rises from zero to the first speed stage that is a rotational speed that is ½ of the output speed of the first gear train G1. According to this, power transmission can be started from a region having a gear ratio lower than the first gear stage at the time of starting, and fuel consumption at the time of starting can be reduced without causing an unnecessary increase in engine speed. .

  When the first clutch C1 is completely engaged, the rotational speed of the ring gear Ri becomes a rotational speed that is ½ of the output speed of the first gear train G1, and power is transmitted at the first gear. From this state, the fixing of the sun gear Sa by the first brake B1 is released, and the engagement force of the third clutch C3 is gradually increased. At this time, the rotational speed of the carrier Ca becomes equal to the output speed of the first gear train G1, and the rotational speed of the ring gear Ri increases from zero to the second gear train G1 as the engagement force of the third clutch C3 increases. It rises to the 2nd gear stage which is equal to the output speed. According to this, as in the case of establishing the first gear, the fuel consumption at the time of starting can be reduced also in the second gear.

  When the third clutch C3 is completely engaged, that is, when the ring gear Ri and the carrier Ca are completely connected, the rotational speed of the ring gear Ri becomes equal to the output speed of the first gear train G1, and the second speed Power transmission at high speed is performed. From this state, the second driven gear G2b is connected to the second intermediate shaft 32 via the second synchronous meshing mechanism SM2 to establish the second gear train G2, and the third clutch C3 is released to release the second clutch C2. Is engaged, the sun gear Sa rotates at the output speed of the second gear train G2. Here, since the carrier Ca rotates at the output speed of the first gear train G1, the ring gear Ri rotates at an intermediate speed between the output speed of the first gear train G1 and the output speed of the second gear train G2. Thus, power transmission at the third gear is performed.

  Next, when the first clutch C1 is released and the third clutch C3 is engaged, the ring gear Ri rotates at the output speed of the second gear train G2, and power transmission at the fourth gear stage is performed. From this state, the third driven gear G3b is connected to the first intermediate shaft via the first synchronous meshing mechanism SM1 to establish the third gear train G3, and the third clutch C3 is released to engage the first clutch C1. When combined, the carrier Ca rotates at the output speed of the third gear train G3. Here, since the sun gear Sa rotates at the output speed of the second gear train G2, the ring gear Ri rotates at an intermediate speed between the output speed of the second gear train G2 and the output speed of the third gear train G3. Thus, power transmission at the fifth gear is performed.

  Next, when the second clutch C2 is released and the third clutch C3 is engaged, the ring gear Ri rotates at the output speed of the third gear train G3, and power transmission at the sixth gear stage is performed. From this state, the fourth driven gear G4b is connected to the second intermediate shaft through the second synchronous meshing mechanism SM2 to establish the fourth gear train G4, and the third clutch C3 is released to engage the second clutch C2. When combined, the sun gear Sa rotates at the output speed of the fourth gear train G4. Here, since the carrier Ca rotates at the output speed of the third gear train G3, the ring gear Ri rotates at an intermediate speed between the output speed of the third gear train G3 and the output speed of the fourth gear train G4. Thus, power transmission at the seventh gear is performed.

  Next, when the first clutch C1 is released and the third clutch C3 is engaged, the ring gear Ri rotates at the output speed of the fourth gear train G4, and power transmission at the eighth gear stage is performed. Further, the second clutch C2 is engaged, the first idle gear GR1 is connected to the idle shaft 8 via the third synchronous mesh mechanism SM3, and the first driven gear G1b is connected to the first synchronous mesh mechanism SM1 through the first synchronous mesh mechanism SM1. When connected to the intermediate shaft, the ring gear Ri rotates in reverse (rotation in the reverse direction) at the same speed as the output speed of the first gear train, thereby transmitting power in the reverse speed.

  As described above, the transmission according to the first embodiment can perform eight forward shifts using the four gear trains G1 to G4. Note that the number of gear trains is not limited to four, and may be five or six, for example. When five gear trains are used, a forward 10-speed shift can be performed, and when six gear trains are used, a forward 12-speed shift can be performed. In other words, assuming that the number of gear trains is N, (2N) speed shifts can be performed. Here, in the first embodiment, the planetary gear 5 and the third clutch C3 are required. However, since the number of gears can be dramatically increased as described above, the speed change can be performed without increasing the shaft length of the transmission. The number of stages can be increased.

  Further, in the first embodiment, the first driven gear G1b can be kept connected to the first intermediate shaft 31 over the three speed ranges from the first gear to the third gear, and the second driven gear G2b Can be kept connected to the second intermediate shaft 32 for three speeds from the third speed to the fifth speed, and the third driven gear G3b can be changed to three speeds from the fifth speed to the seventh speed. The fourth driven gear G4b can remain connected to the second intermediate shaft 32 over the two speeds of the seventh speed and the eighth speed. I can keep it. Accordingly, the number of times the first and second synchronous mesh mechanisms SM1 and SM2 are intermittently connected is greatly reduced, and consumption of the first and second synchronous mesh mechanisms SM1 and SM2 can be remarkably suppressed. In the third speed stage, the fifth speed stage, and the seventh speed stage, power is transmitted via two gear trains, so that the burden on each gear train can be reduced.

  Further, in the conventional dual clutch transmission (DCT), when the two-speed shift is performed, it is not possible to cope with the switching of the first and second clutches, and it is necessary to switch the engagement state of the synchronous meshing mechanism. Takes time and cannot be switched smoothly. Therefore, in the conventional DCT, if the two-speed shift is performed, the responsiveness is lowered, so that it is difficult to realize the two-speed shift. According to the automatic transmission of the present embodiment, the first friction engagement mechanism at the shift speeds (2, 4, 6, 8th speed) in which the third clutch C3 as the third friction engagement mechanism is engaged. A two-speed shift can be performed by simply switching the engagement between the first clutch C1 as the second clutch and the second clutch C2 as the second friction engagement mechanism. For this reason, the two-speed shift can be performed with good responsiveness.

  By the way, in 1st Embodiment, although the 1st and 2nd intermediate shafts 31 and 32 were arrange | positioned on the same axis line as the planetary gear 5, it is not restricted to this. For example, the input shafts 11 and 12 may be disposed on the same axis as the planetary gear 5, and the intermediate shafts 31 and 32 may be disposed in parallel with the axis of the planetary gear 5. In this case, a separate gear train for transmitting the rotation of the intermediate shafts 31 and 32 to the carrier Ca and the sun gear Sa of the planetary gear 5 may be provided.

  In the first embodiment, the differential mechanism is constituted by the double pinion type planetary gear 5, but a single gear comprising a sun gear, a ring gear, and a carrier that pivotally supports the sun gear and the pinion meshing with the ring gear so as to rotate and revolve. You may comprise with a pinion type planetary gear. In this case, the first intermediate shaft 31 may be connected to either the sun gear or the ring gear, the second intermediate shaft 32 may be connected to the other of the sun gear or the ring gear, and the output gear 6 serving as an output member may be connected to the carrier.

  Further, as in the second embodiment shown in FIG. 3, instead of the planetary gear 5 of the first embodiment, a pair of sun gears Sa1 and Sa2 mesh with each other and one is a first sun gear Sa1 and the other is a second sun gear Sa2. A pair of pinions Pi1 ′ and Pi2 ′ that mesh with each other may be constituted by a planetary gear 5 ′ that includes a carrier Ca that is pivotally supported so as to rotate and revolve.

  In the planetary gear 5 ', the first intermediate shaft 31 is connected to the first sun gear Sa1, the second intermediate shaft 32 is connected to the second sun gear Sa2, and the output gear 6 that is an output member is connected to the carrier Ca. Therefore, in the second embodiment, the first sun gear Sa1 is the first rotating element, the second sun gear Sa2 is the second rotating element, and the carrier Ca is the third rotating element. The number of teeth of the first sun gear Sa1 and the number of teeth of the second sun gear Sa2 are set to be the same, and the carrier Ca rotates at an intermediate speed between the rotational speed of the first sun gear Sa1 and the rotational speed of the second sun gear Sa2. . The third clutch C3, which is the third friction engagement mechanism, is configured to be able to engage the second sun gear Sa2 and the carrier Ca, and the first brake B1, which is the fourth friction engagement mechanism, is configured to move the second sun gear Sa2 to the transmission case. 7 is configured to be freely fixed. Other configurations are the same as those of the first embodiment.

  According to the multi-stage transmission of the second embodiment, the pair of pinions Pi1 ′, Pi2 ′ can be meshed in the circumferential direction, and compared with the first embodiment, the planetary gear is equivalent to the ring gear and one pinion. Can be reduced, and interference in the radial direction with other vehicle parts such as a differential gear can be suppressed.

  In both embodiments, a planetary gear is used as the differential mechanism. However, the differential mechanism is supported by a first side gear on one side in the axial direction, a second side gear on the other side in the axial direction, and a pinion that meshes with both side gears. A side gear and pinion gear type differential gear mechanism including a gear case that performs the above-described operation may be used. In this case, the first intermediate shaft is connected to the first side gear as the first rotating element, the second intermediate shaft is connected to the second side gear as the second rotating element, and the output gear as the output member is connected to the gear case. What is necessary is just to comprise so that it may be set as a 3rd rotation element, and both side gears may be connected by the 3rd clutch C3 which is a 3rd friction engagement mechanism. In this case, when the first side gear and the second side gear rotate at different speeds, the gear case rotates at an intermediate speed between the rotation speed of the first side gear and the rotation speed of the second side gear, and the same as in the first embodiment. Shifting can be performed.

  In the first embodiment, the drive gears G1a to G4a of the gear trains G1 to G4 are fixed to the corresponding input shafts 11 and 12, and the driven gears G1b to G4b are pivotally supported to the corresponding intermediate shafts 31 and 32. The driven gears G1b to G4b of the gear trains G1 to G4 may be supported by the corresponding intermediate shafts 31 and 32, and the drive gears G1a to G4a may be supported by the corresponding input shafts 11 and 12, respectively. In this case, a first synchronous mesh mechanism SM1 that selectively couples the first drive gear G1a and the third drive gear G3a to the first input shaft 11 is disposed on the first input shaft 11, and the second input shaft 12 The second synchronous gear mechanism SM2 that selectively connects the second drive gear G2a and the fourth drive gear G4a to the second input shaft 12 may be disposed. Alternatively, one of the synchronous mesh mechanisms SM1 and SM2 may be disposed on the first input shaft 11 or the first intermediate shaft 31, and the other may be disposed on the second input shaft 12 or the second intermediate shaft 32. Is possible.

  Moreover, in 1st, 2nd embodiment, although 1st brake B1 which is a 4th friction engagement element is provided, this 1st brake B1 does not need to be provided. According to this, the number of gear trains can be set to N, and (2N-1) stages of gear shifting can be performed, and the number of gear stages can be increased without increasing the shaft length, the number of axes, and the outer shape of the transmission. .

  Further, the gear ratio of the planetary gears 5 and 5 ′, which are the differential mechanisms of the first and second embodiments, is determined by comprehensive judgment in consideration of the transmission ratio setting of the entire transmission. With a gear ratio of 2.0 exemplified in the embodiment, the gear train can be established within a certain width (for example, 1.6 to 2.4). The same applies to other differential mechanisms such as a side gear / pinion gear type differential gear mechanism.

The skeleton figure which shows the multi-stage transmission of 1st Embodiment of this invention. Explanatory drawing explaining the speed change operation | movement of the multistage transmission of 1st Embodiment. The skeleton figure which shows the multistage transmission of 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... 1st input shaft, 12 ... 2nd input shaft, 2 ... Spring wheel (flywheel), 31 ... 1st intermediate shaft, 32 ... 2nd intermediate shaft, 41-43 ... Synchronous sleeve, 5 ... Planetary gear, Sa ... Sun gear , Ri ... ring gear, Ca ... carrier, Pi1, Pi2 ... pinion, 6 ... output gear, 7 ... transmission case, 8 ... idle shaft, GR1 ... first idle gear, GR2 ... second idle gear, G1-G4 ... first 1st to 4th gear train, G1a to G4a ... 1st to 4th drive gear, G1b to G4b ... 1st to 4th driven gear, C1 to C3 ... 1st to 3rd clutch (1st to 3rd friction engagement) Mechanism), B1... First brake (fourth friction engagement mechanism), SM1 to SM3... First to third synchronous meshing mechanisms.

Claims (5)

A multi-stage transmission that outputs a rotation speed of an input shaft rotated by power of a drive source to a plurality of stages through a plurality of gear trains having different speed ratios, and outputs from the output member.
A first input shaft that fixes or pivotally supports the drive gear of each odd-numbered gear train in the gear ratio order; a second input shaft that fixes or pivotally supports the drive gear of each even-numbered gear train in the gear ratio order; A first friction engagement mechanism for releasably transmitting the power of the drive source to the first input shaft; a second friction engagement mechanism for releasably transmitting the power of the drive source to the second input shaft;
A first intermediate shaft that supports or fixes a driven gear that meshes with the drive gear of each odd-numbered gear train in the gear ratio order, and a driven gear that meshes with the drive gear of each even-numbered gear train in the gear ratio order. A second intermediate shaft to be supported or fixed;
Of the drive gear and the driven gear of each odd-numbered gear train in the gear ratio order, a gear supported by the first input shaft or the first intermediate shaft is connected to the shaft, and the odd-numbered gear in the gear ratio order. The first synchronous meshing mechanism that selectively establishes one of the rows and the drive gear and the driven gear of each even-numbered gear train in the gear ratio order are supported by the second input shaft or the second intermediate shaft. A second synchronous meshing mechanism that connects the gear to the shaft and selectively establishes one of the even-numbered gear trains in the gear ratio order;
The first rotation element has three rotation elements that can rotate relative to each other, and the third rotation element rotates at a different speed when the first rotation element and the second rotation element rotate at different speeds. A differential mechanism configured to rotate at a speed between the rotation speed of the first rotary element and the second rotary element, and a third friction engagement mechanism that connects two of the three rotary elements of the differential mechanism And
A first intermediate shaft and a second intermediate shaft are connected to the first rotating element and the second rotating element of the differential mechanism, respectively, and a third rotating element of the differential mechanism is connected to the output member. Multi-stage transmission.   2. The multi-stage transmission according to claim 1, wherein the first intermediate shaft and the second intermediate shaft are arranged on the same axis as the differential mechanism.   The multi-stage transmission according to claim 1 or 2, wherein the idle shaft is arranged in parallel with the first and second input shafts, and is supported by or fixed to the idle shaft and any gear train is provided. The first idle gear meshing with the drive gear, the second idle gear fixed or pivotally supported by the idle shaft and meshed with the driven gear of any gear train, and the idle gear pivotally supported by the idle shaft can be released freely. And a third synchromesh mechanism coupled to the idle shaft.   4. The multi-stage transmission according to claim 1, wherein the differential mechanism is connected to a first sun gear as a first rotating element connected to the first intermediate shaft and to a second intermediate shaft. A second sun gear as a second rotating element, and a carrier as a third rotating element that supports a pair of pinions that mesh with each other and one of them meshes with the first sun gear and the other meshes with the second sun gear. A multi-stage transmission comprising a planetary gear.   4. The multi-stage transmission according to claim 1, wherein the differential mechanism is constituted by a planetary gear, and a fourth friction engagement mechanism capable of fixing the second rotating element of the planetary gear to the transmission case. 5. A multi-stage transmission comprising:

Images