JPH0472095B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic transmission having a gear train with four forward speeds and one reverse speed with overdrive.

(Conventional technology) Automatic transmissions with overdrive improve fuel efficiency and
Since they are excellent in terms of noise reduction, various types of them have been developed in the past. When creating a gear train with four forward speeds and one reverse speed with an overdrive, the gear train described in US Pat. No. 2,725,762 is known, for example. This gear train is operated as shown in Attached Table 1 by adding a clutch _C3 connected to the input shaft IS to the carrier PC of the Lavigneaux type gear train with three forward speeds and one reverse speed as shown in Figure 1. . Here, in Attached Table 1, ○ marks indicate engagement of clutches C ₁ to _{C 3} or operation of brakes B ₁ to _{B 2} , and no marks indicate release of clutches C ₁ to _{C 3} or release of brakes B ₁ to _{B 2} . . Although the gear train with four forward speeds and one reverse speed with overdrive configured as described above has a simple structure, the rear sun gear _S2 has a rotation speed approximately 2.2 times the rotation speed of the input shaft _A1 , that is, the slip rate of the torque converter. If you ignore the engine output shaft A ₀ per minute
When rotating at 6,000 rpm, the sun gear S ₂ rotates at a high rotation speed of 13,200 rpm, which was disadvantageous in terms of vibration and durability.

Here, the concept of a collinear chart for determining each gear ratio and the rotation speed of each member in a gear train will be explained. As is well known, the planetary gear set consists of a ring gear R, a carrier PC connected to a planetary pinion,
It consists of a sun gear S, and the rotational speeds of these are N _R , N _PC , and N _S respectively, and (number of sun gear teeth) / (number of ring gear teeth) is α (positive in the case of a single pinion,
(in the case of a double pinion, it is taken as negative), then the relational expression N _R +α・N _S −(1+α)・N _PC =0 holds true between them. Therefore, as shown in Fig. 2, the rotational speed of each member of ring gear R, carrier PC, and sun gear S is taken as the vertical axis, and the vertical axes [R], [PC], and [S] are expressed as [] []: [ ] [
]
If they are drawn apart from each other so that =α:1, the coordinates of the intersection of any straight line and each vertical axis in this coordinate plane will satisfy the above equation.

When this collinear chart is applied to the Lavigneaux-type gear train of 3 forward speeds and 1 reverse speed shown in FIG. 1, the result is as shown in FIG. 3. To obtain this alignment chart, follow the steps below.

Here, ring gear R and pinion carrier PC
Looking at the ring gear R and pinion carrier PC, the sun gear S ₁ constitutes a simple planetary gear set on the front side, while the pinion pin PP ₂ and sun gear S ₂ constitute a front simple planetary gear set.
The ring gear R and the pinion carrier PC constitute the rear double pinion planetary gear set, so for convenience of gear ratio calculation, the ring gear R and the pinion carrier PC are the parts that act as the front planetary gear set R ₁ , PC ₁ and the rear side We will proceed with the discussion by replacing the parts that act as a planetary gear set with R ₂ and PC ₂ .

(a) First, front ring gear R ₁ , carrier PC ₁ ,
Set the coordinate axes of sun gear S ₁ [R ₁ ], [PC ₁ ], and [S ₁ ] as shown in Figure 2: [ ₁ ] [ ₁ ]: [ ₁ ] [ ₁ ] =
Draw so that α ₁ :1. Here, α ₁ is the ratio of the number of teeth between the ring gear R ₁ and the sun gear S ₁ of the front planetary gear set.

(b) Since the rear carrier PC ₂ and ring gear R2 are connected to the front carrier PC ₁ and ring gear R 1 respectively, the coordinate axes of the rear carrier PC ₂ and ring gear _{R 2 are} [PC ₂ ] [R ₂ ] is [PC ₁ ], [R ₁ ]
The same coordinate axes as The coordinate axis [S ₂ ] of the rear sun gear S ₂ is [ ₂ ] [ ₂ ]: [ ₂ ] [ ₂ ] = -
Draw at a position where α ₂ :1.

(c) When clutches C ₁ , C ₂ , and C ₃ are engaged, they connect to the front sun gear S ₁ and the rear sun gear, respectively.
S ₂ , both the front and rear carriers PC ₁ and PC ₂ are rotated at the same number of revolutions as the engine output shaft A ₀ , so if the number of revolutions of the input shaft A ₁ is set to 1 in Fig. 3, then correspond to this [S ₁ ] , [S ₂ ], [PC ₁ ], [PC ₂ ], mark the 1 position.

(d) When the brakes B ₁ and B ₂ are activated, both the front and rear carriers PC ₁ , PC ₂ ,
Since the front sun gears S ₁ and S ₂ are fixed and their rotational speed is zero, in Fig. 3, [PC ₁ ],
Mark the zero position of [PC ₂ ] [S ₁ ].

(e) Clutches C ₁ to _{C 3} and brakes in Attached Table 1
Depending on the operating state of B ₁ and B ₂ , mark ○ and mark ● in a straight line (1st speed), (2nd speed), (3rd speed),
Connect in (4th gear) and (reverse).

(f) The coordinate axis of the front ring gear R ₁ and the rear ring gear R ₂ from which the straight line ~ takes out the output [R ₁ ],
If you mark ◎ at the point where it intersects with [R ₂ ], you can calculate each gear ratio from each ◎ mark. That is, in the figure, if the rotation speed of the input shaft A ₁ is set to 1, the reciprocals of the longitudinal lengths of G ₁ to _{G 5} are respectively 1st speed, 2nd speed, 3rd speed, 4th speed,
This is the reverse gear ratio, and this value can be obtained from the proportional calculation in FIG.

The gear ratio determined by the above procedure is shown in Attached Table 1. In this table, the minus sign attached to the reverse gear ratio means that the output shaft _A2 rotates in the opposite direction to the first to fourth forward speeds. In addition, in Fig. 3, each coordinate axis [S ₂ ], [R ₁ ]-[R ₂ ], [PC ₁ ]-
Each intersection of [PC ₂ ], [S ₁ ] and the straight line ~ represents the rotational speed of each member in 1st to 4th forward speed and in reverse, so from now on, when in 4th forward speed (i.e. overdrive), the rear The side sun gear S ₂ has the highest rotational speed N _S2 of each member, that is, the input shaft
Rotates at (1+α ₁ /α ₂ ) times A ₁ . In this case, the values of α ₁ and α ₂ must be the highest for each gear ratio, so they cannot be arbitrarily selected and are limited to approximately constant values. In this gear train, α ₁ = 0.5, α ₂ = 0.417
(values actually used by Ford), each gear ratio will be as listed in Attached Table 1, and sun gear S ₂ will rotate at 2.2 times that of input shaft A ₁ .

(Problem to be Solved by the Invention) As described above, in the conventional gear train with four forward speeds and one reverse speed with overdrive, which uses only two planetary gear sets, the gear train is connected to the input shaft _A1 via the forward clutch _C1 . The first shaft is connected to the input shaft A1 via a direct connection/reverse clutch _C2 , and the brake _B2 is connected to the input shaft _A1 in second gear.
A gear train with three forward speeds and one reverse speed has a second shaft fixed by the brake _B1 in the first gear and a third shaft fixed by the brake B1 in reverse, and a fourth shaft connected to the output shaft _A2 . , a clutch _C3 is provided that connects the third shaft and the input shaft _A1 at the fourth speed, and a gear train that operates the brake _B2 to obtain overdrive, that is, two planetary gear sets (rotating element 6, free Rotating element 4 is a gear train with 2 degrees of freedom, which combines two pairs of rotating elements of degree 4), so the first axis is input axis A ₁ and 2.
I couldn't avoid spinning at more than double the number of revolutions.

Therefore, conventionally, in order to prevent certain rotating elements from rotating at high speeds as mentioned above, as disclosed in Japanese Patent Publication No. 51-9092, one set of planetary gears was added to the Simpson type gear train with three forward speeds and one reverse speed. There is also a gear train with four forward speeds and one reverse speed with an overdrive by adding a brake and one brake, but this requires a large number of parts and is disadvantageous in terms of weight, space, and cost. It was hot.

(Object of the Invention) The present invention was made in view of the above-mentioned conventional problems, and its purpose is to eliminate high-speed rotating elements and make it advantageous in terms of vibration and durability.

(Means for Solving the Problems) The above object is to provide a first planetary gear set including a first ring gear R ₁ , a first pinion carrier PC ₁ and a first sun gear S ₁ and a second ring gear R ₂ , second pinion carrier PC ₂ and second sun gear S ₂
a second planetary gear set including: a first brake B ₁ capable of fixing the first pinion carrier PC ₁ ;
a second brake _B2 capable of fixing the first sun gear _S1 , and the first pinion carrier _PC1 ;
and a second pinion carrier _P2 are connected to form an integral rotating element, the second sun gear _S2 and the output shaft of the engine are connected via a torque converter, and the second pinion carrier PC ₂ and the output shaft of the engine are connected via the first clutch _C1 ,
The first ring gear R ₁ is connected to an output shaft of a transmission, and the first sun gear S ₁ and the second sun gear S ₂ are connected to the output shaft of a transmission.
This can be achieved by connecting the first ring gear _R1 and the second ring gear _R2 through a _third clutch _C3 .

Alternatively, a first ring gear R ₁ , a first pinion carrier PC ₁ and a first sun gear S ₁
A second planetary gear set including a second ring gear R ₂ , a second pinion carrier PC ₂ and a second sun gear S ₂ and the first pinion carrier PC ₁ can be fixed. a first brake _B1 , and a second brake capable of fixing the first sun gear _S1 .
B ₂ , the second ring gear R ₂ and the first pinion carrier PC ₁ are connected to form an integral rotating element, and the first sun gear S ₁ and the second sun gear
_S2 is connected via a second clutch _C2 , the second sun gear _S2 and the engine output shaft are connected via a torque converter, and the second ring gear _R2 and the engine output shaft are connected via a torque converter. and the first clutch C ₁
The first ring gear _R1 is connected to the output shaft of the transmission, and the first sun gear _S1 and the second pinion carrier _PC2 are connected to each other via a third clutch.
This can be achieved by linking via _C3 .

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

[Case 1] One simple planetary gear set and one double pinion planetary gear set are provided, and a clutch is connected to the output shaft. FIG. 4 is a diagram showing an embodiment of Case 1.
In Fig. 4, T/C is a torque converter whose pump impeller is connected to an engine output shaft _A0 , and an input shaft _A1 of this torque converter T/C is connected to a turbine runner T.
It is coupled to sun gear S ₁ as a reaction force element via C ₂ and also coupled to sun gear S ₂ as a first element. The sun gear _S1 can be fixed by a brake _B2 . Engine output shaft A ₀ is connected via clutch C ₁ to carrier PC ₂ as the second element.
and pinion pin PP ₂ , these carrier PC ₂ and pinion pin PP ₂ are connected to carrier PC ₁ as an input element, and this carrier
PC ₁ can be fixed by means of brake B ₁ . U is a stator. A planetary pinion P ₁ supported by a carrier PC ₁ is meshed with both a sun gear S ₁ and a ring gear R ₁ as an output element.
Pinion gear PG ₂ supported by pinion pin PP ₂
meshes with sun gear S ₂ and also meshes with planetary pinion P ₂ which is pivotally supported by carrier PC ₂ . A ring gear R ₂ as a third element meshing with the planetary pinion P ₂ is connected to the ring gear R ₁ and the output shaft A ₂ via a clutch C ₃ . As mentioned above, one clutch _C3 is connected to the output shaft. Note that the output shaft _A2 is connected to a final reduction gear (not shown). The sun gear mentioned above
S ₁ , planetary pinion P ₁ , carrier PC ₁ and ring gear R ₁ constitute a first simple planetary gear set G, and sun gear S ₂ , pinion gear PG ₂ , pinion pin PP ₂ , planetary pinion P ₂ , carrier PC ₂ and Ring gear _R2 constitutes a second double pinion planetary gear set W.

Attached Table 2 shows the clutches C ₁ , C ₂ , C ₃ at each gear stage of the embodiment having rotating elements in the coupling relationship shown in FIG.
and the operating status of brakes B ₁ and B ₂ , and
The gear ratio is shown using a general formula and a numerical example when α ₁ =α ₂ =0.45. In this case, the rotating element that rotates at the highest speed is ring gear R ₁ , which is connected to the engine output shaft.
Rotates at 1.45 times A ₀ . In addition, in this example, the speed is 55% in 3rd gear.
It is a power split type with a direct connection ratio of 100% in 4th gear.

[Case 2] One set of simple planetary gear sets and one set of double pinion planetary gear sets are provided, and a clutch is connected between rotating elements other than the output shaft. Fig. 5 is a diagram showing an example of case 2. It is.
In FIG. 5, T/C is a torque converter whose pump impeller is connected to an engine output shaft _A0 , and an input shaft _A1 of this torque converter T/C is connected to a turbine runner T.
It is coupled to sun gear S ₁ as a reaction force element via C ₂ , and sun gear S ₂ as the first element.
is combined with U is a stator. sun gear
Both a carrier PC ₂ as a third element and a pinion pin PP ₂ are connected to S ₁ via a clutch C ₃ , and a pinion gear PG ₂ in mesh with a sun gear S ₂ is pivotally supported on the pinion pin PP ₂ . A planetary pinion _P2 meshing with a pinion gear _PG2 is pivotally supported on the carrier _PC2 . Sun gear S ₁ and pinion pin PP ₂ mentioned above, carrier
PC ₂ can be fixed by means of brake B ₂ . A ring gear R ₂ as a second element meshing with a planetary pinion P ₂ is coupled to an engine output shaft A ₀ via a clutch C ₁ and also to a carrier PC ₁ as an input _element . can be fixed by brake B ₁ . A planetary pinion _P1 that meshes with a sun gear _S1 is pivotally supported on the carrier _PC1 , and a ring gear _R1 as an output element coupled to an output shaft _A2 meshes with this planetary pinion _P1 . In this embodiment, all clutches C ₁ , C ₂ and C ₃ are coupled between rotating elements other than the output shaft. Note that the output shaft _A2 is connected to a final reduction gear (not shown).

The aforementioned sun gear S ₁ , planetary pinion P ₁ ,
The carrier PC ₁ and the ring gear R ₁ constitute the first simple planetary gear set G, and the sun gear S ₂ and the pinion gear
PG ₂ , pinion pin PP ₂ , planetary pinion
P ₂ , carrier PC ₂ and ring gear R ₂ are the second
It constitutes a heavy pinion planetary gear set W.

Attached Table 3 shows the clutches C ₁ , C ₂ , C ₃ at each gear stage of the embodiment having rotating elements in the coupling relationship shown in FIG.
and the operating status of brakes B ₁ and B ₂ , and
The gear ratio is shown using a general formula and a numerical example when α ₁ =α ₂ =0.45. In this case, the rotating element that rotates at the highest rotational speed is the ring gear _R1 , which rotates at 1.45 of the engine output shaft _A0 when in fourth gear. Note that this embodiment is a power split type with a direct coupling ratio of 63% in third gear and 100% in fourth gear.

In each of the above embodiments, the front planetary gear set located on the torque converter side is simply represented by adding a suffix [1] (for example, S ₁ , P _1, etc.) to each element code. The rear planetary gear set located on the output side is similarly indicated with the subscript [2]. Here, the correspondence relationship between the first and second planetary gear sets referred to in the claims is shown in Attached Table 4.

(Effects) As described above, according to the present invention, the element that rotates at the maximum rotation speed can be the first ring gear _R1 , and the rotation speed N _R1 of the first ring gear _R1 is the output of the transmission. Since the shaft rotational speed N _A2 is also high, it is possible to eliminate elements that rotate at a high speed exceeding the output shaft rotational speed N _A2 of the transmission, which is advantageous in terms of vibration and durability.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a gear train with four forward speeds and one reverse speed with overdrive used in a conventional automatic transmission, Fig. 2 is an explanatory diagram showing the concept of a collinear chart, and Fig. 3 is a diagram showing the gear train of four forward speeds and one reverse speed with overdrive. FIG. 4 is a diagram showing a collinear diagram of the gear train shown in FIG. Figure 5 shows an example of a gear train, one set of simple planetary gears and one set of double pinion planetary gears.
FIG. 3 is a diagram showing an embodiment of the gear train of the automatic transmission of the present invention in Case 2, in which the gear train is assembled and a clutch is installed on a member other than the output member. A ₀ ... Engine output shaft, A ₁ ... Input shaft (transmission input shaft), A ₂ ... Output shaft (transmission output shaft),
T/C...torque converter, _B1 ...brake (first brake), _B2 ...brake (second brake), _C1 ...clutch (first clutch),
C ₂ ... Clutch (second clutch), C ₃ ... Clutch (third clutch), S ₁ ... Sun gear (first
sun gear), S ₂ ... sun gear (second sun gear), R ₁ ... ring gear (first ring gear),
R ₂ ...Ring gear (second ring gear), PC ₁ ...
...pinion carrier (first pinion carrier),
PC ₂ ...Pinion carrier (second pinion carrier).

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Claims (1)

[Claims] 1. A first planetary gear set including a first ring gear R ₁ , a first pinion carrier PC ₁ and a first sun gear S ₁ ; a second ring gear R ₂ and a second pinion; a second planetary gear set including a carrier PC ₂ and a second sun gear S ₂ ; a first brake B ₁ capable of fixing the first pinion carrier PC ₁ ; and a first sun gear S _1. a fixable second brake _B2 , the first pinion carrier _PC1 and the second pinion carrier _P2 are connected to form an integral rotating element, and the second sun gear _S2 and the output shaft of the engine is connected via a torque converter; the second pinion carrier _PC2 and the output shaft of the engine are connected via a first clutch _C1 ; and the first ring gear _R1 is connected to the output shaft of a transmission, the first sun gear _S1 and the second sun gear _S2 are connected via a second clutch _C2 , and the first ring gear _R1 and the second ring gear
An automatic transmission with an overdrive, characterized in that _R2 is connected via a third clutch _C3 . 2 a first planetary gear set including a first ring gear R ₁ , a first pinion carrier PC ₁ and a first sun gear S ₁ ; a second ring gear R ₂ , a second pinion carrier PC ₂ and a first planetary gear set; a second planetary gear set including two sun gears _S2 ; a first brake _B1 capable of fixing the first pinion carrier PC1; and a second brake _B1 capable of fixing the first sun gear _S1 . a brake _B2 , the second ring gear _R2 and the first pinion carrier _PC1 are connected to form an integral rotating element, and the first sun gear _S1 and the second sun gear _S2 are connected to each other. The second sun gear _{S2 and} the engine output shaft are connected via a torque converter, and the second ring gear _R2 and the engine output shaft are connected to the first clutch C2. The first ring gear _R1 is connected to the output shaft of the transmission, and the first sun gear _S1 and _the second pinion carrier _PC2 are connected to each other via a third clutch C1. Automatic transmission with overdrive characterized by being connected via ₃ .