JP2009138829A - Automatic transmission for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the flexibility of setting the ratio of respective shift stages, while enhancing mechanical transmission efficiency, by eliminating a Ravigneau type shifting planetary gear unit from a shifting planetary gear unit. <P>SOLUTION: An automatic transmission T of forward 7 stages and backward 1 stage has a double pinion type speed reduction planetary gear unit PUr, the shifting planetary gear unit PUs constituted by combining first and second planetary gear units PU1 and PU2 of a single pinion type in both and having four differential rotary elements, and six frictional engaging elements Ca, Cb, Cc, C1, B1 and B2 of a wet multiple disc type or a band brake type. The shift stage of forward 1 speed-forward 7 speed and backward 1 speed is established by selectively fastening three pieces of the six frictional engaging elements. Since a Ravigneau type planetary gear unit is not used, the mechanical transmission efficiency is enhanced, and the flexibility of setting the ratio of the respective shift stages can also be enhanced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a planetary gear unit for reduction provided with three differential rotating elements, a planetary gear unit for transmission including four differential rotating elements, which is composed of a combination of a first planetary gear unit and a second planetary gear unit, and a wet type. The present invention relates to an automatic transmission for a vehicle in which at least five frictional engagement elements composed of a multi-plate type clutch or brake are arranged around the axis of an input shaft.

By combining a planetary gear unit for deceleration, a planetary gear unit for Ravigneaux type shifting, and six friction engagement elements comprising a wet multi-plate type clutch or brake, a forward 1st speed to a forward 7th speed and a reverse 1st speed An automatic transmission capable of establishing a gear position is known from Patent Document 1 and Patent Document 2 below.
Japanese Patent No. 3736481 JP 2005-54824 A

By the way, the Ravigneaux type planetary gear unit for transmission used in Patent Documents 1 and 2 is a combination of a single-pinion type first planetary gear unit and a double-pinion type second planetary gear unit, and is a double-pinion type. The one planetary gear unit of the second planetary gear unit and the pinion of the single-pinion type first planetary gear unit are made of a common member, or are joined together so as to be able to rotate integrally. There was a problem of low transmission efficiency.

Further, the Ravigneaux type planetary gear unit for speed change used in Patent Documents 1 and 2 has two carriers shared among six differential rotation elements in total and two ring gears shared. For this reason, there is a problem in that the coupling relationship between the remaining four differential rotation elements is determined, and the ratio setting freedom of each gear is reduced.

The present invention has been made in view of the above-described circumstances, and is intended to increase the degree of freedom in setting the ratio of each gear stage while eliminating the Ravigneaux-type planetary gear unit for shifting from the planetary gear unit for shifting and increasing the mechanical transmission efficiency. Objective.

In order to achieve the above object, according to the first aspect of the present invention, a reduction planetary gear unit including three differential rotation elements, and a combination of a first planetary gear unit and a second planetary gear unit are configured. This is an automatic transmission for a vehicle in which a planetary gear unit for speed change having four differential rotation elements and at least six friction engagement elements made of a wet multi-plate type clutch or brake are arranged around the axis of the input shaft. Connecting a third differential rotation element of the first planetary gear unit and a second differential rotation element of the second planetary gear unit to an output shaft, and a first differential rotation element of the second planetary gear unit;
The first and second clutches are respectively disposed between the second differential rotation element and the first differential rotation element of the first planetary gear unit, and the reduction output of the reduction planetary gear unit connected to the input shaft is A third clutch is disposed between the input third differential rotation element of the second planetary gear unit and the first differential rotation element of the first planetary gear unit;
A fourth clutch and a first brake are arranged between the second differential rotation element of the first planetary gear unit, the input shaft and the housing, respectively, and three differentials in the speed diagram of the speed reduction planetary gear unit are provided. The rotating elements are arranged in the order of a first differential rotating element, a third differential rotating element, and a second differential rotating element, and the first differential rotating element is an input element from an input shaft, and the second difference A vehicular automatic transmission is proposed, in which a second brake is disposed between the dynamic rotation element and the housing, and the third differential rotation element is used as an output element to the transmission planetary gear unit.

According to the second aspect of the present invention, in addition to the configuration of the first aspect, the distance between the first differential rotation element and the third differential rotation element in the velocity diagram of the speed reduction planetary gear unit is calculated. A vehicular automatic transmission is proposed in which the distance is set equal to the distance between the third differential rotation element and the second differential rotation element.

According to the invention described in claim 3, in addition to the structure of claim 1, the third brake is arranged between the third differential rotation element of the second planetary gear unit and the housing. An automatic transmission for a vehicle is proposed.

According to the invention described in claim 4, in addition to the configuration of claim 1, the second brake is abolished and the second differential rotation element of the speed reduction planetary gear unit is always restrained to the housing. A feature of an automatic transmission for a vehicle is proposed.

According to the configuration of the first aspect, since it is not necessary to configure the planetary gear unit for reduction with a Ravigneaux-type planetary gear unit having a complicated structure and low mechanical transmission efficiency, the mechanical transmission is compared with a case where a Ravigneaux-type planetary gear unit is used. Efficiency can be increased. Further, by selectively engaging the first to third clutches, the coupling relationship of the four differential rotation elements of the shifting planetary gear unit can be changed to three types, and the degree of freedom in setting the ratio of each gear can be increased. In addition, in the case of having six or more frictional engagement elements, three frictional engagement elements are fastened when each gear is established. The number of open frictional engagement elements that generate drag resistance can be reduced, and loss due to oil friction can be reduced. In addition, the speed reduction planetary gear unit that decelerates the rotation of the input shaft and transmits it to the speed change planetary gear unit is composed of a double pinion type planetary gear unit. In addition, the degree of freedom in setting the common ratio can be increased.

According to the second aspect of the present invention, the first speed diagram of the speed reduction planetary gear unit is shown.
Since the distance between the differential rotation element and the third differential rotation element is set equal to the distance between the third differential rotation element and the second differential rotation element, the output is output with respect to the input rotation speed of the speed reduction planetary gear unit. The number of revolutions can be set to one half. As a result, the input to the first differential rotation element or the input to the second differential rotation element can be switched without changing the ratio of the planetary gear unit for reduction, and the degree of freedom in layout is improved and the automatic transmission It becomes easy to set a preferable ratio.

According to the third aspect of the present invention, since the third brake is disposed between the third differential rotation element of the second planetary gear unit and the housing, only the third brake is added to the seven-speed automatic transmission. Thus, an automatic transmission with 8 forward speeds can be obtained.

According to the fourth aspect of the present invention, the second brake is abolished and the second differential rotation element of the speed reduction planetary gear unit is always restrained by the housing, so the second brake is abolished from the automatic transmission of the seventh forward speed. Thus, an automatic transmission with six forward speeds can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 and 2 show a first embodiment of the present invention. FIG. 1 is a skeleton diagram of a vehicle automatic transmission, and FIG. 2 is a speed diagram of the vehicle automatic transmission.

As shown in FIG. 1, the automatic transmission T for forward 1st to 7th forward and 1st reverse for automobiles is
Reduction planetary gear unit P composed of double pinion type planetary gear unit
Ur and a transmission planetary gear unit PUs each composed of a first planetary gear unit PU1 and a second planetary gear unit PU2 each formed of a single pinion type planetary gear unit.

The planetary gear unit PUr for reduction includes a sun gear Sf, a carrier Cf, a ring gear Rf, a plurality of outer pinions Pfo and an inner pinion P that are supported by the carrier Cf and mesh with the sun gear Sf and the ring gear Rf, respectively.
fi. The first planetary gear unit PU1 includes a sun gear Sm and a carrier Cm
And a ring gear Rm and a plurality of pinions Pm supported by the carrier Cm and simultaneously meshed with the sun gear Sm and the ring gear Rm. The second planetary gear unit PU2 is
A sun gear Sr, a carrier Cr, a ring gear Rr, and a plurality of pinions Pr supported by the carrier Cr and simultaneously meshed with the sun gear Sr and the ring gear Rr are provided.

A power source (not shown), for example, an input shaft IS driven by an engine, is always connected to the sun gear Sf of the speed reduction planetary gear unit PUr, and an output shaft OS that drives a wheel (not shown) is a ring gear Rm of the first planetary gear unit PU1. And always connected to the carrier Cr of the second planetary gear unit PU2.

The input shaft IS can be coupled to the carrier Cm of the first planetary gear unit PU1 via the fourth clutch C1, and the carrier Cm of the first planetary gear unit PU1 is coupled to the sun gear Sr of the second planetary gear unit PU2 via the first clutch Ca. The sun gear Sr of the second planetary gear unit PU2 can be coupled to the sun gear Sm of the first planetary gear unit PU1 via the second clutch Cb. The sun gear Sm of the first planetary gear unit PU1 can be coupled via the third clutch Cc. Reduction planetary gear unit PUr
Can be coupled to the ring gear Rf of the second planetary gear unit PU2 and the ring gear Rr of the second planetary gear unit PU2.

The carrier Cm of the first planetary gear unit PU1 can be coupled to the housing H via the first brake B1, and the carrier Cf of the deceleration planetary gear unit PUr can be coupled to the housing H via the second brake B2.

The first to fourth clutches Ca, Cb, Cc, C1 are all configured by a wet multi-plate type, and the first and second brakes B1, B2 are configured by a wet multi-plate type or a band brake type. Is done.

FIG. 2 shows a speed diagram of the automatic transmission T. The upper speed diagram is for the speed reduction planetary gear unit PUr, and the middle speed diagram is for the first planetary gear unit PU1 of the speed change planetary gear unit PUs. The lower speed diagram is for the second planetary gear unit PU2 of the speed-changing planetary gear unit PUs.

In Table 1, i, j, and k represent the gear ratios of the ring gear and the sun gear of the reduction planetary gear unit PUr, the first planetary gear unit PU1, and the second planetary gear unit PU2, respectively.

In the reduction planetary gear unit PUr, the number of teeth of the ring gear Rf is ZRf,
When the number of teeth of the sun gear Sf is ZSf, the gear ratio i is set to ZRf / ZSf = 2.000.

In the first planetary gear unit PU1, when the number of teeth of the ring gear Rm is ZRm and the number of teeth of the sun gear Sm is ZSm, the gear ratio j is set to ZRm / ZSm = 2.000.

In the second planetary gear unit PU2, when the number of teeth of the ring gear Rr is ZRr and the number of teeth of the sun gear Sr is ZSr, the gear ratio k is set to ZRr / ZSr = 1.700.

In the speed diagram of the speed reduction planetary gear unit PUr, the first planetary gear unit PU1 and the second planetary gear unit PU2 in FIG. 2, when the distance between the vertical line of the carrier and the vertical line of the ring gear is 1.000, the vertical line of the carrier And the distance between the vertical line of the sun gear
The tooth number ratios i, j, and k are set, respectively.

In FIG. 1, the first planetary gear unit P of the transmission planetary gear unit PUs.
U1 includes three differential rotating elements, a sun gear Sm, a carrier Cm, and a ring gear Rm.
The second planetary gear unit PU2 includes a sun gear Sr, a carrier Cr, and a ring gear Rr.
The ring gear Rm of the first planetary gear unit PU1 and the carrier Cr of the second planetary gear unit PU2 are always coupled.

When the first clutch Ca is engaged, the carrier C of the first planetary gear unit PU1.
m and the sun gear Sr of the second planetary gear unit PU2 are integrated, and the second clutch C
When b is engaged, the sun gear Sm of the first planetary gear unit PU1 and the sun gear Sr of the second planetary gear unit PU2 are integrated, and when the third clutch Cc is engaged, the first gear
The sun gear Sm of the planetary gear unit PU1 and the ring gear Rr of the second planetary gear unit PU2 are integrated. Thus, a total of 6 differential rotation elements of the first planetary gear unit PU1 and 3 differential rotation elements of the second planetary gear unit PU2 are obtained.
By constantly integrating two of the differential rotation elements and selectively integrating the other two, the transmission planetary gear unit PUs has four differential rotation elements. .

In FIG. 2, “engaged state a” indicates a state where the first clutch Ca is engaged, “engaged state b” indicates a state where the second clutch Cb is engaged, and “engaged state c” indicates a state where the third clutch Cc is engaged. The shape of the speed diagram of the planetary gear unit PUs for shifting can be changed into three types according to the engaged state of the first to third clutches Ca to Cc.

Table 2 is an operation table of the automatic transmission T according to the first embodiment. In the left column, 1 to 7 represent the first forward speed to the seventh forward speed, and R represents the reverse speed. Further, ◯ indicates that the friction engagement element is in a fastening state, and (◯) indicates a state in which the friction engagement element does not relatively rotate. If the frictional engagement element does not rotate relative to it, there is no difference in operation whether it is fastened or not fastened. However, the consumption of hydraulic pressure generated by the oil pump and the solenoid valve that controls the hydraulic pressure are not affected. It is more economical not to conclude from the viewpoint of reducing power consumption.

Further, in Table 2, “common ratio” is the ratio of the ratios of the adjacent forward shift speeds, and “reci orange” is the ratio of the ratio between the first forward speed and the seventh forward speed.

Next, the establishment of each gear stage will be described with reference to the operation table of the automatic transmission T shown in Table 2.

As is apparent from Table 2, among the first forward speed to the seventh forward speed and the reverse speed,
The second brake B2 is engaged at the speeds other than the sixth forward speed. Therefore, since the carrier Cf of the speed reduction planetary gear unit PUr is constrained by the housing H, when the rotation of the input shaft IS is input to the sun gear Sf of the speed reduction planetary gear unit PUr, the ring gear Rf of the speed reduction planetary gear unit PUr, The ring gear Rr of the directly connected second planetary gear unit PU2 rotates at a predetermined rotational speed (hereinafter referred to as a reduced rotational speed N2) reduced with respect to the rotational speed of the input shaft IS (hereinafter referred to as a full speed rotational speed N1). To do. In the present embodiment, when the full-speed rotation speed N1 is 1.00, the reduction speed N2 is 0.50 (that is, N2 is one half of N1) due to the gear ratio i = 2.000, and the single pinion It is possible to obtain a reduction rotational speed N2 that is impossible with the type of planetary gear unit PUr for speed reduction.

When establishing the first forward speed, the second clutch Cb and the first brake B1 are engaged in addition to the second brake B2.

By engaging the second clutch Cb, the sun gear Sm of the first planetary gear unit PU1 and the sun gear Sr of the second planetary gear unit PU2 are integrated, and the transmission planetary gear unit PUs is in the engaged state b of FIG. Further, when the first brake B1 is engaged, the carrier Cm of the first planetary gear unit PU1 is restrained by the housing H and stops rotating. Therefore, in the speed diagram, the rotation speed of the ring gear Rr of the second planetary gear unit PU2 becomes the reduction rotation speed N2, and the rotation speed of the carrier Cm of the first planetary gear unit PU1 becomes 0, so that the ratio is 5.529. The first gear is established.

When establishing the second forward speed, the first clutch Ca and the first brake B1 are engaged in addition to the second brake B2.

By engaging the first clutch Ca, the carrier Cm of the first planetary gear unit PU1 and the sun gear Sr of the second planetary gear unit PU2 are integrated, and the speed-change planetary gear unit PUs is in the engaged state a in FIG. Further, when the first brake B1 is engaged, the carrier Cm of the first planetary gear unit PU1 is restrained by the housing H and stops rotating, whereby the sun gear of the second planetary gear unit PU2 connected to the carrier Cm via the first clutch Ca. Sr also stops rotating. Therefore, in the speed diagram, the rotation speed of the ring gear Rr of the second planetary gear unit PU2 becomes the reduction rotation speed N2, and the rotation speed of the sun gear Sr of the second planetary gear unit PU2 becomes 0, so that the forward ratio is 3.176. A second gear is established.

When establishing the third forward speed, the first clutch Ca and the second clutch Cb are engaged in addition to the second brake B2.

By engaging the first clutch Ca and the second clutch Cb, the carrier Cm of the first planetary gear unit PU1, the sun gear Sr of the second planetary gear unit PU2, and the sun gear Sm of the first planetary gear unit PU1 are integrated. The first planetary gear unit PU1 is in a locked state where differential rotation is impossible by integrating the carrier Cm and the sun gear Sm, and the ring gear Rm is also integrated. Since the ring gear Rm is always integrated with the carrier Cr of the second planetary gear unit PU2, the sun gear Sr and the carrier Cr of the second planetary gear unit PU2 are integrated to achieve a locked state in which differential rotation is impossible. The ring gear Rr is also integrated. That is, at the third forward speed, the first and second planetary gear units PU1 and PU2 are both locked, and the third clutch Cc that is not engaged is in a substantially engaged state in which the third clutch Cc is not relatively rotated. As a result, the rotation of the ring gear Rr of the second planetary gear unit PU2 rotating at the decelerating speed N2 is output as it is to the output shaft OS, and the forward third speed gear stage with a ratio of 2.000 is established.

When establishing the fourth forward speed, the first clutch Ca and the fourth clutch C1 are engaged in addition to the second brake B2.

By engaging the first clutch Ca, the carrier Cm of the first planetary gear unit PU1 and the sun gear Sr of the second planetary gear unit PU2 are integrated, and the speed-change planetary gear unit PUs is in the engaged state a in FIG. In addition, when the fourth clutch C1 is engaged, the carrier Cm of the first planetary gear unit PU1 is connected to the input shaft IS, so that the carrier Cm rotates at the same full-speed rotation speed N1 as that of the input shaft IS. Therefore, in the speed diagram, the rotation speed of the ring gear Rr of the second planetary gear unit PU2 becomes the reduction rotation speed N2, and the rotation speed of the carrier Cm of the first planetary gear unit PU1 becomes the full speed rotation speed N1, so that the ratio is 1. The forward 4th speed of 459 is established.

When establishing the fifth forward speed, the second clutch Cb and the fourth clutch C1 are engaged in addition to the second brake B2.

By engaging the second clutch Cb, the sun gear Sm of the first planetary gear unit PU1 and the sun gear Sr of the second planetary gear unit PU2 are integrated, and the transmission planetary gear unit PUs is in the engaged state b of FIG. In addition, when the fourth clutch C1 is engaged, the carrier Cm of the first planetary gear unit PU1 is connected to the input shaft IS, so that the carrier Cm rotates at the same full-speed rotation speed N1 as that of the input shaft IS. Therefore, in the speed diagram, the rotation speed of the ring gear Rr of the second planetary gear unit PU2 becomes the reduction rotation speed N2, and the rotation speed of the carrier Cm of the first planetary gear unit PU1 becomes the full speed rotation speed N1, so that the ratio is 1. The fifth forward speed 221 is established.

When the forward sixth speed is established, the second brake B2 is exceptionally released, and the second clutch Cb, the third clutch Cc, and the fourth clutch C1 are engaged.

By engaging the second clutch Cb and the third clutch Cc, the ring gear Rr and the sun gear Sr of the second planetary gear unit PU2 are integrated, so that the second planetary gear unit PU2 enters a locked state in which differential rotation is impossible. Further, the engagement of the second clutch Cb results in the sun gear Sr of the second planetary gear unit PU2 and the first planetary gear unit PU.
1 sun gear Sm and the carrier C of the second planetary gear unit PU2
Since r is always integrated with the ring gear Rm of the first planetary gear unit PU1,
By integrating the sun gear Sm and the ring gear Rm of the first planetary gear unit PU1, the first planetary gear unit PU1 is also in a locked state in which differential rotation is impossible. That is, at the sixth forward speed, the first and second planetary gear units PU1 and PU2 are both locked, and the first clutch Ca that is not engaged is in a substantially engaged state in which it does not rotate relatively.
And, by engaging the fourth clutch C1, the carrier C of the first planetary gear unit PU1
When the full-speed rotation speed N1 of the input shaft IS is input to m, the rotation of the carrier Cm is output to the output shaft OS as it is, and a forward sixth speed gear stage with a ratio of 1.000 is established.

When establishing the seventh forward speed, the third clutch Cc and the fourth clutch C1 are engaged in addition to the second brake B2.

By engaging the third clutch Cc, the ring gear Rr of the second planetary gear unit PU2
Are integrated with the sun gear Sm of the first planetary gear unit PU1, and the planetary gear unit for shifting PUs is in the engaged state c in FIG. Further, the first clutch C1 is engaged to engage the first.
When the carrier Cm of the planetary gear unit PU1 is connected to the input shaft IS, the carrier Cm rotates at the full speed rotation speed N1. Therefore, in the speed diagram, the rotation speed of the ring gear Rr of the second planetary gear unit PU2 becomes the reduction rotation speed N2, and the rotation speed of the carrier Cm of the first planetary gear unit PU1 becomes the full speed rotation speed N1, so that the ratio becomes 0. 800
The forward seventh gear is established.

When the reverse speed is established, the third clutch Cc and the first brake B1 are engaged in addition to the second brake B2.

By engaging the third clutch Cc, the ring gear Rr of the second planetary gear unit PU2
Are integrated with the sun gear Sm of the first planetary gear unit PU1, and the planetary gear unit for shifting PUs is in the engaged state c in FIG. Also, the first brake B1 is engaged and the first
When the carrier Cm of the planetary gear unit PU1 is connected to the housing H, the carrier Cm stops rotating. Therefore, in the speed diagram, the second planetary gear unit PU
The rotation speed of the ring gear Rr of No. 2 becomes the reduction speed N2, and the first planetary gear unit PU
When the number of rotations of one carrier Cm becomes zero, a reverse speed gear ratio of -4.0000 is established.

As described above, according to the present embodiment, the first planetary gear unit PU1 and the second planetary gear unit PU2 constituting the planetary gear unit PUs for shifting are both configured as a single pinion type planetary gear unit, and the Ravigneaux type gear shifting is performed. Because no planetary gear unit is used, the mechanical transmission efficiency can be increased and the fuel consumption of the engine can be reduced.

In addition, by selectively engaging the first to third clutches Ca to Cc, the shape of the speed diagram of the planetary gear unit PUs for shifting is changed into three types, and the degree of freedom in setting the ratio of each gear stage is increased. Can do. Usually, for that purpose, 4 planetary gear units PUs for shifting are installed.
According to the present embodiment, this can be achieved by the two planetary gear units of the first planetary gear unit PU1 and the second planetary gear unit PU2. Therefore, the automatic transmission This can contribute to the downsizing of T.

In addition, when establishing the forward 1st speed shift stage to the forward 7th speed shift stage and the reverse shift speed, three of the six frictional engagement elements are always engaged, and therefore, in the open state. The number of frictional engagement elements that increase the friction caused by oil is reduced by one compared to those described in the cited document 1 and cited document 2, and the friction is reduced by that amount, thereby reducing the fuel consumption of the engine. be able to.

Furthermore, since the double planetary gear unit PUr with the outer pinion Pfo and the inner pinion Pfi is used for the deceleration planetary gear unit PUr, the degree of freedom in setting the deceleration speed N2 is much greater than when using a single pinion type. To improve. For example, in the embodiment, it becomes possible to set the decelerating speed N2 to 0.50 with respect to the full speed speed N1 = 1.00, and the degree of freedom for setting the ratio and the common ratio of each gear stage can be set. Can be increased.

It is also possible to set all the gear ratios to be the same as in the second embodiment to be described later. In this case, by unifying the specifications of the teeth of the ring gear and sun gear, It is possible to reduce the cost by sharing the cutter.

  Next, a second embodiment of the present invention will be described based on FIG. 3 and FIG.

In the first embodiment, four clutches Ca, Cb, Cc, C1 and two brakes B are used.
1 and B2 can be used to establish the first forward speed to the seventh forward speed and the first reverse speed. The second embodiment is different from the first embodiment in that the third brake B3 is used. By adding, it is possible to establish a shift stage from the first forward speed to the eighth forward speed and the first reverse speed. That is, the automatic transmission T according to the first embodiment includes a total of six friction engagement elements and can establish the first forward speed to the seventh forward speed and the first reverse speed. The automatic transmission T of the form is provided with a total of seven friction engagement elements, and can establish the first forward speed to the eighth forward speed and the first reverse speed.

As is apparent from FIG. 3, the third brake B3 is a planetary gear unit PUs for shifting.
The ring gear Rr of the second planetary gear unit PU2, that is, the ring gear Rf of the speed reduction planetary gear unit PUr integrated with the ring gear Rr is constrained with respect to the housing H, and other configurations are the same as those of the first embodiment. It is.

However, in the first embodiment, the gear ratio of the second planetary gear unit PU2 is k = ZRr /
What was ZSr = 1.700 (see Table 1) is changed to a tooth number ratio k = ZRr / ZSr = 2.000 in the second embodiment, as shown in Table 3.

As is obvious from comparison between Table 4 which is the operation table of the second embodiment and Table 2 which is the operation table of the first embodiment, the forward 8-speed gear stage of the second embodiment is shown. Operation is the same except when established. When the forward eighth speed is established, the second brake B2 is released, and the third clutch C
c, the fourth clutch C1 and the third brake B3 are engaged.

By engaging the third clutch Cc, the ring gear Rr of the second planetary gear unit PU2
And the sun gear Sm of the first planetary gear unit PU1 are integrated, and the shifting planetary gear unit PUs is in the engaged state c of FIG. Further, the first clutch C1 is engaged to engage the first.
When the carrier Cm of the planetary gear unit PU1 is connected to the input shaft IS, the carrier Cm rotates at the full speed rotation speed N1. In addition, the ring gear Rr of the second planetary gear unit PU2 is restrained by the housing H by the engagement of the third brake B3 and stops rotating. Therefore, in the speed diagram, the rotation speed of the ring gear Rr of the second planetary gear unit PU2 is 0.
Thus, when the rotation speed of the carrier Cm of the first planetary gear unit PU1 becomes the full speed rotation speed N1, a forward 8-speed gear stage with a ratio of 0.667 is established.

As described above, in the second embodiment, the forward 8-speed shift is performed only by adding the third brake B that restrains the ring gear Rf of the speed reduction planetary gear unit PUr (that is, the ring gear Rr of the second planetary gear unit PU2) to the housing H. A stage can be established.

Other functions and effects of the second embodiment are the same as the functions and effects of the first embodiment described above.

  Next, a third embodiment of the present invention will be described with reference to FIGS.

In the first embodiment, four clutches Ca, Cb, Cc, C1 and two brakes B are used.
1, B2 can be used to establish the first forward speed to the seventh forward speed and the first reverse speed, but the third embodiment uses the second brake B2 of the first embodiment. By abolishing and always restraining the carrier Cf of the planetary gear unit PUr for deceleration to the housing H, the forward 1
It is possible to establish a speed range from high speed to 6 forward speeds and 1 reverse speed. In other words, the automatic transmission T according to the first embodiment includes a total of six friction engagement elements and can establish the first forward speed to the seventh forward speed and the first reverse speed. The automatic transmission T of the form is provided with a total of five friction engagement elements, and can establish the first forward speed to the sixth forward speed and the first reverse speed.

As is apparent from a comparison between Table 5 which is the operation table of the third embodiment and Table 2 which is the operation table of the first embodiment, in the third embodiment, in the first embodiment, The forward seventh speed gear stage is deleted, and the forward seventh speed stage is moved up to the sixth forward speed stage.

Other functions and effects of the third embodiment are the same as the functions and effects of the first embodiment described above. However, in the third embodiment, since the number of frictional engagement elements to be fastened at each shift stage is two, the number of frictional engagement elements that are in an open state and increase the friction due to oil is reduced. The effect of reducing the friction and reducing the fuel consumption of the engine cannot be expected.

The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

For example, the numerical values of the tooth number ratios i, j, and k and the numerical values of the ratios in each embodiment are merely examples, and can be changed as appropriate.

In the planetary gear unit PUr for reduction of the first to third embodiments described above, the sun gear Sf is an input element, the carrier Cf is a fixed element, and the ring gear Rf is an output element. Like the speed reduction planetary gear unit PUr, the sun gear Sf can be changed to a fixed element, the carrier Cf can be changed to an input element, and the ring gear Rf can be changed to an output element. In this case, the carrier Cf is not necessarily restricted to the housing H via the second brake B2, and may be always restricted to the housing H as in the third embodiment.

When the reduction rotation speed N2 is set to one half of the full speed rotation speed N1 by the double pinion type reduction planetary gear unit PUr, the sun gear S is not changed without changing the ratio.
The input to f or the input to the carrier Cf can be exchanged, so that the degree of freedom in layout is improved and the preferred ratio of the automatic transmission T can be easily set.

Skeleton diagram of automatic transmission for vehicle according to first embodiment Speed diagram of vehicular automatic transmission according to first embodiment Skeleton diagram of automatic transmission for vehicle according to second embodiment Speed diagram of vehicular automatic transmission according to second embodiment Skeleton diagram of automatic transmission for vehicle according to third embodiment Speed diagram of vehicular automatic transmission according to third embodiment Skeleton diagram and velocity diagram of planetary gear unit for reduction according to fourth embodiment

Explanation of symbols

PUr Deceleration planetary gear unit PUs Shift planetary gear unit PU1 First planetary gear unit PU2 Second planetary gear unit Sf Sun gear (first differential rotation element of deceleration planetary gear unit)
Cf carrier (second differential rotation element of the planetary gear unit for reduction)
Rf ring gear (third differential rotation element of planetary gear unit for reduction)
Sm Sun gear (first differential rotating element of the first planetary gear unit)
Cm carrier (second differential rotating element of the first planetary gear unit)
Rm ring gear (third differential rotation element of the first planetary gear unit)
Sr sun gear (first differential rotation element of the second planetary gear unit)
Cr carrier (second differential rotating element of the second planetary gear unit)
Rr ring gear (third differential rotation element of the second planetary gear unit)
Ca First clutch Cb Second clutch Cc Third clutch C1 Fourth clutch B1 First brake B2 Second brake B3 Third brake IS Input shaft OS Output shaft H Housing

Claims (4)

A planetary gear unit for reduction (PUr) comprising three differential rotating elements;
1st planetary gear unit (PU1) and 2nd planetary gear unit (PU2)
A planetary gear unit for speed change comprising four differential rotating elements (
PUs)
At least five frictional engagement elements (Ca
, Cb, Cc, C1, B1, B2, B3), and
Is an automatic transmission for a vehicle that is arranged around the axis of the input shaft (IS),
A third differential rotation element (Rm) of the first planetary gear unit (PU1) and a second differential rotation element (Cr) of the second planetary gear unit (PU2) are connected to an output shaft (OS);
A first differential rotation element (Sr) of the second planetary gear unit (PU2);
The first and second clutches (Ca, Cb) are arranged between the second differential rotation element (Cm) and the first differential rotation element (Sm) of the planetary gear unit (PU1), respectively.
The third differential rotation element (Rr) of the second planetary gear unit (PU2) to which the deceleration output of the deceleration planetary gear unit (PUr) connected to the input shaft (IS) is input.
) And the first differential rotation element (Sm) of the first planetary gear unit (PU1), a third clutch (Cc) is disposed,
A fourth clutch (C1) and a first brake (B1) are respectively provided between the second differential rotation element (Cm) of the first planetary gear unit (PU1) and the input shaft (IS) and the housing (H). Place and
Three differential rotation elements in the speed diagram of the speed reduction planetary gear unit (PUr) are a first differential rotation element (Sf), a third differential rotation element (Rf), and a second differential rotation element (C
f), the first differential rotation element (Sf) is an input element from the input shaft (IS), and the second differential rotation element (Cf) and the housing (H) 2 brakes (B2)
And the third differential rotation element (Rf) is connected to the speed change planetary gear unit (PUs).
An automatic transmission for a vehicle, characterized in that it is an output element. The distance between the first differential rotation element (Sf) and the third differential rotation element (Rf) in the velocity diagram of the speed reduction planetary gear unit (PUr) is defined as the third differential rotation element (Rf).
f) and the distance between the second differential rotating element (Cf) is set equal to,
The automatic transmission for a vehicle according to claim 1. The vehicular vehicle according to claim 1, wherein a third brake (B3) is disposed between the third differential rotation element (Rr) of the second planetary gear unit (PU2) and the housing (H). Automatic transmission. The said 2nd brake (B2) was abolished and the 2nd differential rotation element (Cf) of the said planetary gear unit (PUr) for deceleration was always restrained by the housing (H), The Claim 1 characterized by the above-mentioned. Automatic transmission for vehicles.

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