JP2004239349A - Transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission which allows increase in the number of gear stages without increasing an axial length and width dimensions. <P>SOLUTION: A transmission has a transmission input shaft 10 and a transmission intermediate output shaft 20 of a transmission output shaft which are mutually disposed in parallel. A single pinion type planetary gear 40 provided to an engine output shaft 30 is equipped with a sun gear 41 fixed to the engine output shaft 30, a ring gear 42 arranged outside the sun gear 41 and fixed thereto, and a carrier 43 for supporting a pinion gear 44. A first multiple disc clutch 31 is arranged between the engine output shaft 30 and the transmission input shaft 10. A second multiple disc clutch 32 is arranged between the transmission input shaft 10 and the single pinion type planetary gear 40. A transmission path for transmitting engine output to the transmission input shaft 10 is provided with a first transmission path for executing transmission through the medium of the first multiple disc clutch 31, the single pinion type planetary gear 40, and a second transmission path for executing transmission through the medium of the second multiple disc clutch 32. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transmission of a parallel shaft type, and more particularly to a transmission capable of increasing the number of gears without increasing the shaft length.
[0002]
[Prior art]
As a transmission, there is a parallel shaft type in which a plurality of constantly meshing transmission gear trains are provided between an input shaft and an output shaft arranged in parallel with each other. The transmission gear train for transmitting power is switched by a meshing clutch such as a synchronous meshing mechanism. The parallel shaft type transmission becomes a manual transmission when the switching operation is performed by a driver's shift lever operation, and becomes an automatic transmission when the switching operation is automatically performed by a hydraulic actuator.
[0003]
To increase the number of gears of the transmission in order to improve the power performance, fuel efficiency, and the like of the vehicle, it is necessary to increase the number of transmission gear trains. However, if the number of speed change gear trains is increased to increase the number of shift speeds, the shaft length of the transmission becomes longer, so that the protruding portion, that is, the tunnel, which protrudes into the vehicle interior, becomes large, and the comfortability deteriorates. Further, when the input torque increases, the required shaft diameter of the shaft constituting the transmission increases, and the diameter of the tunnel further increases, thereby deteriorating the livability.
[0004]
In order to increase the number of gears without increasing the shaft length, a transmission having a three-shaft configuration having two input shafts parallel to each other and an output shaft parallel to each other is disclosed in, for example, Patent Document 1.
[0005]
[Patent Document 1]
JP 2001-99246 A
[Problems to be solved by the invention]
However, in such a three-shaft transmission, although the shaft length of the transmission can be shortened, the width of the transmission becomes large because the number of input shafts is two.
[0007]
An object of the present invention is to provide a transmission capable of increasing the number of gears without increasing the shaft length and the vertical width.
[0008]
[Means for Solving the Problems]
The transmission of the present invention includes a transmission input shaft provided with a plurality of drive gears, a transmission output shaft provided with a driven gear meshing with the drive gear, the drive gear and the driven gear. A transmission switching mechanism that switches a transmission gear train that transmits the transmission input shaft to the driven gear, an engine output shaft that outputs engine output to the transmission input shaft, and the transmission input. A first multi-plate clutch provided between the shaft, a sun gear, a ring gear disposed outside the sun gear, and a carrier supporting a pinion gear meshing with the sun gear and the ring gear; Of the three components, a ring gear and a carrier, one of a sun gear and a ring gear is a fixed component, and one of the remaining two components is the engine output shaft. A single pinion type planetary gear having input elements to be connected and one remaining component being an output element; and a second multi-plate clutch provided between the transmission input shaft and the output element. A transmission path for transmitting an engine output to the transmission input shaft, a first transmission path for transmitting the engine output shaft from the engine output shaft via the first multiple disc clutch, and a single pinion type transmission for transmitting the engine output from the engine output shaft. It is characterized in that it is formed by a planetary gear and a second transmission path for transmission via the second multi-plate clutch.
[0009]
In the transmission according to the present invention, the transmission output shaft may include a transmission intermediate output shaft provided with the driven gear and arranged in parallel with the transmission input shaft, and a power output from the transmission intermediate output shaft via a gear train. And a transmission final output shaft which is transmitted and is arranged in parallel with the transmission input shaft.
[0010]
The transmission of the present invention is characterized in that the input element is a sun gear, the output element is a carrier, and the fixed element is a ring gear.
[0011]
According to the present invention, between the engine output shaft and the transmission input shaft, a transmission path transmitting from the engine output shaft via the first multiple disc clutch, and a single pinion type planetary gear from the engine output shaft to the And a transmission path for transmitting the engine output to the transmission input shaft at different rotational speeds via the respective paths, so that a plurality of transmission gear trains are provided. In each of the above, two speed shifts of a high speed stage and a low speed stage can be performed. As a result, it is possible to obtain a transmission that performs a multi-stage transmission without increasing the shaft length and the width.
[0012]
Further, the transmission of the present invention is a parallel shaft type in which the transmission input shaft and the transmission output shaft are arranged in parallel with each other, and the members used for the manual transmission can be shared with the automatic transmission. Thus, an automatic transmission can be manufactured at low cost.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a skeleton diagram showing a transmission according to an embodiment of the present invention. The transmission has a transmission input shaft 10 and a transmission intermediate output shaft 20 which forms a transmission output shaft. They are rotatably mounted parallel to each other in a transmission case (not shown). A first drive gear 11 and a second drive gear 12 having a larger diameter than this are fixed to the transmission input shaft 10. Further, the transmission input shaft 10 is provided with a third drive gear 13 having a larger diameter than the second drive gear 12 and a fourth drive gear 14 having a larger diameter than the second drive gear 12 so as to be relatively rotatable. Mounted on the shaft 10.
[0014]
A first driven gear 21 that constantly meshes with the drive gear 11 to form a first transmission gear train, and a second gear train that constantly meshes with the drive gear 12 is formed on the transmission intermediate output shaft 20. The second driven gear 22 is mounted so as to be relatively rotatable. Further, a third driven gear 23 that constantly meshes with the drive gear 13 to form a third transmission gear train, and a fourth driven gear 24 that constantly meshes with the drive gear 14 to form a fourth transmission gear train. Each is fixed to the transmission intermediate output shaft 20. The speed ratio of each speed change gear train is represented by the ratio Zout / Zin between the number of teeth Zout of the driven gear and the number of teeth Zin of the drive gear, and the speed ratio decreases from the first to the fourth speed change gear train. ing.
[0015]
In order to switch the power transmission from the transmission input shaft 10 to the transmission intermediate output shaft 20 to one of the first transmission gear train and the second transmission gear train, the transmission intermediate output shaft 20 has a first switching mechanism. A mechanism 15 is provided, and a second switching mechanism 16 is provided on the transmission input shaft 10 to switch between the third transmission gear train and the fourth transmission gear train. Each of the switching mechanisms 15 and 16 is formed by a synchromesh, that is, a synchronous meshing mechanism, and the first switching mechanism 15 is meshed with a switching hub 27 fixed to the transmission intermediate output shaft 20 and is always in axial engagement with the switching hub 27. And a slidable switching sleeve 28. When the switching sleeve 28 is engaged with the spline 21a integrated with the driven gear 21, the first transmission gear train is in a power transmission state, and when the switching sleeve 28 is engaged with the spline 22a integrated with the driven gear 22, The second speed change gear train enters a power transmission state.
[0016]
The second switching mechanism 16 has a switching hub 17 fixed to the transmission input shaft 10 and a switching sleeve 18 constantly meshed with the switching hub 17 and slidable in the axial direction. When the switching sleeve 18 is engaged with the spline 13a integrated with the drive gear 13, the third transmission gear train is in a power transmission state, and when the switching sleeve 18 is engaged with the spline 14a integrated with the drive gear 14, The fourth speed change gear train enters the power transmission state. The switching sleeves 18 and 28 of the switching mechanisms 15 and 16 are automatically switched by a hydraulic actuator (not shown) according to the running state of the vehicle. In addition, the first switching mechanism 15 may be mounted on the transmission input shaft 10, and the second switching mechanism 16 may be mounted on the transmission intermediate output shaft 20.
[0017]
As described above, the illustrated transmission is a parallel-shaft type automatic transmission in which a shift operation is automatically performed, and can share members constituting a manual transmission in which a shift operation is performed by a driver's manual operation. As a result, the transmission can be manufactured at low cost.
[0018]
An engine output shaft 30 arranged coaxially with the transmission input shaft 10 is connected to a crankshaft of the engine via a damper or the like. Between them, first and second multi-plate clutches 31 and 32 are provided to set a path for transmitting the engine output to the transmission input shaft 10 in two systems. Reference numeral 32 denotes a wet clutch.
[0019]
The first multi-plate clutch 31 has a clutch hub 33 integrated with the engine output shaft 30 and a clutch drum 34 integrated with the transmission input shaft 10. A plurality of drive-side clutch discs 33a are arranged outside the clutch hub 33, and when these clutch discs 33a come into close contact with the plurality of clutch discs 34a arranged inside the clutch drum 34, the engine output becomes the first multiple. The transmission is directly connected to the transmission input shaft 10 via the plate clutch 31 and transmitted. When the contact is released, the power transmission is cut off.
[0020]
The second multi-plate clutch 32 is disposed coaxially outside the first multi-plate clutch 31, and includes a clutch drum 35 integrated with the transmission input shaft 10 and a clutch hub 36 disposed inside the clutch drum 35. And A plurality of drive-side clutch disks 36a are arranged outside the clutch hub 36, and a plurality of driven-side clutch disks 35a are arranged inside the clutch drum 35. A single pinion type planetary gear 40 is mounted between the transmission input shaft 10 and the engine output shaft 30. The planetary gear 40 is a sun gear or sun gear 41 that rotates integrally with the engine output shaft 30, and is not shown. A pinion gear 44 meshing with the sun gear 41 and the ring gear 42 is rotatable on a carrier 43 having an annular gear or a ring gear 42 fixed to the transmission case and integrated with the clutch hub 36 of the second multiple disc clutch 32. It is attached to.
[0021]
When the engine output shaft 30 is rotating, the carrier 43 is also rotating. When the clutch disks 35a and 36a of the second multiple disk clutch 32 are brought into close contact with each other, the engine output is transmitted through the second multiple disk clutch 32. When power is transmitted to the transmission input shaft 10 and the contact state is released, power transmission is interrupted. As shown in FIG. 1, when the ring gear 42 of the single pinion type planetary gear 40 is fixed, the following relationship is established between the rotation Ns of the sun gear 41 and the rotation Nc of the carrier 43. Nc = {ρ / (1 + ρ)} × Ns where ρ is ρ = Zs / Zr, where Zs is the number of teeth of the sun gear 41 and Zr is the number of teeth of the ring gear 42.
[0022]
Therefore, when power is transmitted through the second multi-plate clutch 32, the rotation speed of the engine output shaft 30 is reduced and transmitted to the transmission input shaft 10. However, the single pinion type planetary gear has three configurations: an input element that rotates integrally with the engine output shaft 30, an output element that is connected to the transmission input shaft 10, and a sun gear, a ring gear, and a carrier for a fixed element that is fixed to the transmission case. Since the gear ratio can be changed by a combination of the elements (all six types), other combinations can be applied except for at least combinations (all two types) in which the carrier whose speed ratio is-(reverse rotation) is a fixed element. .
[0023]
Each of the multi-plate clutches 31 and 32 is automatically set to the engaged state and the released state by a hydraulic actuator (not shown) according to the running state. Hydraulic actuators for driving the multi-plate clutches 31 and 32 and hydraulic actuators for driving the switching mechanisms 15 and 16 are supplied with hydraulic oil from a hydraulic pump driven by an engine or an electric motor. .
[0024]
As described above, between the engine output shaft 30 and the transmission input shaft 10, the first transmission path having the first multiple disk clutch 31 and the second multiple disk clutch 32 are provided. A second transmission path is provided for transmitting the output to the transmission input shaft 10 at a lower speed than the transmission path. Accordingly, the first speed change gear train including the drive gear 11 and the driven gear 21 has a high speed stage determined by the speed change ratio of the drive gear 11 and the driven gear 21 by the switching operation of the two multi-plate clutches 31 and 32, and And the speed ratio of the planetary gears, so that two speed stages of the low speed stage determined by the sum of the speed ratio and the speed ratio of the planetary gears are formed. A gear stage is formed. As a result, this transmission becomes a transmission having a total of eight gears by the first to fourth gear trains.
[0025]
In FIG. 1, the first to eighth gears are indicated by reference numerals (1) to (8). In the odd gears of the first, third, fifth and seventh gears, The power transmission is performed via the second transmission path by engaging the second multiple disc clutch 32 and disengaging the first multiple disc clutch 31. On the other hand, in the second, fourth, sixth, and eighth even-numbered speeds, the first multiple disc clutch 31 is engaged and the second multiple disc clutch 32 is disengaged to release the second clutch. Power transmission is performed via one transmission path.
[0026]
In order to transmit the torque of the transmission intermediate output shaft 20 to the drive wheels, a reduction drive gear for forward use, that is, a reduction drive gear 45 attached to the transmission intermediate output shaft 20 is connected to the transmission input shaft 10 and the transmission intermediate shaft. The transmission is in mesh with a reduction driven gear (reduction driven gear) 47 attached to a transmission final output shaft 46 which constitutes a transmission output shaft arranged in parallel with the output shaft 20. A front wheel drive shaft 48a is rotatably incorporated in the hollow hole of the transmission final output shaft 46. The front wheel drive shaft 48a is connected to the transmission final output shaft 46 via a center differential 49. Is connected to the rear wheel drive shaft 48b.
[0027]
The front wheel drive shaft 48a is connected to a front wheel (not shown) by engaging a drive pinion 51 provided at the tip thereof with a hypoid gear 52 of a front wheel differential. On the other hand, the rear wheel drive shaft 48b is connected to the rear wheels via a propeller shaft (not shown) and a rear wheel differential. Therefore, the transmission shown in FIG. 1 is applied to a four-wheel drive vehicle with an engine installed vertically. However, if the drive pinion 51 is attached to the transmission final output shaft 46 to connect the transmission final output shaft 46 to the front wheels, and the center differential 49 is not provided, this transmission can be used as a transmission for driving the front wheels. .
[0028]
FIG. 2 is a skeleton diagram of the transmission as viewed from a direction along the line AA in FIG. 1. The drive-side reverse gear 54 attached to a reverse shaft 53 arranged in parallel with the transmission final output shaft 46 includes: The gear meshes with the driven gear 22 and also meshes with a driven reverse gear 55 rotatably mounted on the transmission final output shaft 46. The transmission final output shaft 46 is provided with a third switching mechanism 56 for moving the vehicle backward, and this switching mechanism 56 constantly meshes with a switching hub 57 provided on the transmission final output shaft 46. When the switching sleeve 58 is engaged with a spline 55a integrated with the reverse gear 55, the rotation of the transmission intermediate output shaft 20 is reversed to change the speed. It is transmitted to the machine final output shaft 46. Although the driven reverse gear 55 meshes with the driven gear 22 via the driving reverse gear 54, the reverse gear 55 may be meshed with the driven gear 21 or another driven gear. Further, a reverse shaft is provided between the transmission input shaft 10 and the transmission intermediate output shaft 20, and the drive gear 12 and the driven gear 22 are used as reverse gears, and the reverse gear 54 is driven by the reverse gear 54 and the driven gear 22 by the reverse gear 54. In this case, the transmission intermediate shaft 20 becomes the transmission final output shaft.
[0029]
In the transmission described above, by operating the three switching mechanisms 15, 16 and 56 and the two multi-plate clutches 31 and 32, the multi-stage of the forward speed and the reverse speed from the first speed to the eighth speed is realized. The speed change can be performed by four pairs of speed change gear trains. For example, in order to set the transmission to the first speed, the driven mechanism 21 and the transmission intermediate output shaft 20 are engaged by the switching mechanism 15, the first multi-plate clutch 31 is released, and the second Is fastened. As a result, the engine output is transmitted to the transmission input shaft 10 via the second transmission path on the low speed side, and is driven from the transmission input shaft 10 via the transmission intermediate output shaft 20 and the transmission final output shaft 46. Engine power is transmitted to the wheels.
[0030]
To switch from the first gear to the second gear, the first multiple disc clutch 31 is engaged while the driven gear 21 is engaged with the transmission output shaft 20 without operating the switching mechanism 15. Then, the second multiple disc clutch 32 is released. As a result, the engine output is transmitted to the transmission input shaft 10 at a higher speed than the second transmission path via the first transmission path on the high speed side, so that the gearshift operation can be performed without causing torque loss. Done. The same applies to the shift from the third speed to the fourth speed, and when shifting gears via the same speed change gear train, the gear shifting operation can be performed without causing torque loss.
[0031]
As described above, since two speeds of the high speed stage and the low speed stage are performed by each speed change gear train, a multi-stage speed change can be performed without increasing the shaft length and width of the transmission. This makes it possible to reduce the size of the tunnel in which the transmission case protrudes into the vehicle interior, and secure the livability in the vehicle interior.
[0032]
The present invention is not limited to the above embodiment, and can be variously modified without departing from the gist thereof. For example, in the illustrated transmission, four sets of transmission gear trains are provided, but five or more sets may be provided. Although this transmission is an automatic transmission that automatically switches a transmission gear train that transmits power, a manual transmission can be used if the switching operation is performed manually. It is. Further, the transmission output shaft may be constituted by one shaft, instead of being constituted by the transmission intermediate output shaft 20 and the transmission final output shaft 46.
[0033]
【The invention's effect】
According to the present invention, two transmission paths for transmitting the engine output to the transmission input shaft at different rotational speeds are provided between the engine output shaft and the transmission input shaft. Since two speeds, ie, the first speed and the lower speed, can be performed, the multi-speed can be performed without increasing the shaft length and the width.
[0034]
Since the transmission input shaft and the transmission output shaft are parallel-parallel transmissions, the members used for the manual transmission can be shared with the automatic transmission, thereby reducing the manufacturing cost of the transmission. It becomes possible to reduce.
[Brief description of the drawings]
FIG. 1 is a skeleton diagram showing a transmission according to an embodiment of the present invention.
FIG. 2 is a skeleton diagram of the transmission as viewed from a direction along line AA in FIG. 1;
[Explanation of symbols]
Reference Signs List 10 transmission input shafts 11 to 14 drive gear 15 first switching mechanism 16 second switching mechanism 20 transmission intermediate output shaft (transmission output shaft)
21 to 24 driven gear 30 engine output shaft 31 first multi-plate clutch 32 second multi-plate clutch 40 single pinion type planetary gear 41 sun gear 42 ring gear 43 carrier 44 pinion gear 46 transmission final output shaft (transmission output shaft)
56 Switching mechanism

Claims (3)

A transmission input shaft provided with a plurality of drive gears,
A transmission output shaft provided with a driven gear that meshes with the drive gear;
A transmission switching mechanism that switches a transmission gear train that transmits the transmission input shaft to the driven gear among a plurality of transmission gear trains configured by the drive gear and the driven gear;
A first multi-plate clutch provided between an engine output shaft that outputs engine output to the transmission input shaft and the transmission input shaft;
A sun gear, a ring gear disposed outside of the sun gear, and a carrier for supporting a pinion gear meshing with the sun gear and the ring gear; As a fixed element, one of the remaining two components as an input element connected to the engine output shaft, and a single pinion type planetary gear having the remaining one component as an output element;
A second multi-plate clutch provided between the transmission input shaft and the output element,
A first transmission path for transmitting an engine output to the transmission input shaft from the engine output shaft via the first multi-plate clutch; and a single-pinion type planetary gear from the engine output shaft. And a second transmission path for transmitting power via the second multi-plate clutch. The transmission according to claim 1, wherein the transmission output shaft is provided with the driven gear, a transmission intermediate output shaft arranged in parallel with the transmission input shaft, and a gear train from the transmission intermediate output shaft. And a transmission final output shaft which is driven by the power and is arranged in parallel with the transmission input shaft. 3. The transmission according to claim 1, wherein the input element is a sun gear, the output element is a carrier, and the fixed element is a ring gear.

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