JP3102047B2 - Planetary gear train of automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary gear train of an automatic transmission comprising two sets of simple planetary gear mechanisms and another set of transmission means such as a simple planetary gear mechanism.

[0002]

2. Description of the Related Art A conventional planetary gear train of an automatic transmission, particularly a planetary gear train of an automatic transmission having three sets of simple planetary gear mechanisms, is disclosed in, for example, U.S. Pat. No. 4,070,927.
No. 6,397,859, which uses three sets of simple planetary gear mechanisms to enable six gears.

[0003]

However, in the planetary gear train of the conventional automatic transmission, all three simple planetary gear mechanisms are operated at the fifth speed, which is frequently used, in power transmission. Since two sets of simple planetary gear mechanisms operate at the sixth speed, there are problems in terms of power transmission efficiency and gear noise.

[0004] There is also a problem that there is a component rotating at a high speed in the fifth speed and the sixth speed. The present invention has been made in view of the above problems,
It is an object of the present invention to improve the efficiency of power transmission at the fifth speed and the sixth speed, reduce gear noise, and reduce the number of rotations of components that rotate at high speed.

[0005]

To achieve the above object, a planetary gear train of an automatic transmission according to the present invention has a first transmission means and a second transmission means interposed between an input shaft and an output shaft. Let
A second simple planetary gear mechanism having a second sun gear, a second ring gear and a second planet carrier as the second transmission means, and a third simple planetary gear having a third sun gear, a third ring gear and a third planet carrier; The input shaft and the second sun gear are connected or connectable by using a planetary gear train including a mechanism, and the second planet carrier and the third planet carrier are connected and the connection shaft is connectable to the input shaft. , The second ring gear and the third sun gear can be connected, and the third sun gear and the third planet carrier can be fixed to the stationary portion, respectively.
The ring gear is connected to the output shaft, and the input shaft and the third sun gear can be connected via the first transmission means.

[0006] As the first transmission means, a first sun gear,
A first simple planetary gear mechanism having a first ring gear and a first planet carrier is provided, and the first sun gear is connected or connectable to the input shaft, and the first planet carrier is connected to the third sun gear. One ring gear may be fixed to the stationary part.

In addition, a first simple planetary gear mechanism having a first sun gear, a first ring gear, and a first planet carrier is provided as the first transmission means, and the first ring gear is connected to or connectable to an input shaft, The first planet carrier may be connectable to the third sun gear, and the first sun gear may be fixed to the stationary part.

A first simple planetary gear mechanism of a double pinion type provided with a first sun gear, a first ring gear and a first planet carrier is provided as the first speed change means.
The first sun gear is connected or connectable to the input shaft,
The first ring gear may be connectable to the third sun gear, and the first planet carrier may be fixed to the stationary part.

[0009]

The second planetary carrier is connected to the third planetary carrier, and the second ring gear can be connected to the third sun gear, so that the second simple planetary gear mechanism is connected to the third simple planetary gear mechanism and the second speed change is performed. Means, a power input from an input shaft to a second sun gear or a third planet carrier is enabled for the second transmission means, and a third ring gear is integrally connected to an output shaft to form a power output side. Further, the planet carrier or the sun gear of the third simple planetary gear mechanism can be fixed, and the power from the input shaft shifted by the first transmission means can be transmitted to the third sun gear, as described later. Advance 6 as shown in 2
Get the number of speeds.

In order to obtain the fifth speed, only the third simple planetary gear mechanism and the first speed change means are operated to transmit the power from the input shaft shifted by the first speed change means to the third sun gear. The power from the input shaft that is not shifting is transmitted to the carrier.

To obtain the sixth speed, only the third simple planetary gear mechanism is operated, the third sun gear is fixed, and power from the input shaft that does not shift is transmitted to the third planet carrier.

[0012] In the planetary gear train of the automatic transmission according to the second aspect,
As the first transmission means, a first simple planetary gear mechanism for shifting by fixing a ring gear is provided, the first sun gear is used as a power input side connected to an input shaft, and the first planet carrier is used as a power output side after shifting. To transmit the shifted power from the input shaft to the third sun gear.

[0013] In the planetary gear train of the automatic transmission according to the third aspect,
As the first transmission means, a first simple planetary gear mechanism for shifting by fixing a sun gear is provided, the first ring gear is used as a power input side connected to an input shaft, and the first planet carrier is used as a power output side after shifting. To transmit the shifted power from the input shaft to the third sun gear.

[0014] In the planetary gear train of the automatic transmission according to the fourth aspect,
As the first speed change means, a double pinion type first simple planetary gear mechanism for shifting by fixing the planet carrier is provided, the first sun gear is used as a power input side connected to the input shaft, and the first ring gear is shifted after shifting. As a power output side, the power from the input shaft that has been shifted can be transmitted to the third sun gear.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of a planetary gear train of an automatic transmission according to the present invention.

First, the configuration will be described. In the figure, N indicates an input shaft connected to an output shaft on the engine (not shown).
U designates an output shaft, and three sets of simple planetary gear mechanisms G1 to G3, first and second brakes B are provided between the input shaft N and the output shaft U.
1, B2 and first to third clutches C1 to C3.

In the three sets of simple planetary gear mechanisms, the first simple planetary gear mechanism G1 includes a first sun gear S1, a first ring gear R1, and a first planet carrier PC1.
The second simple planetary gear mechanism G2 includes a second sun gear S2, a second ring gear R2, and a second planet carrier PC2, and the third simple planetary gear mechanism G3 includes a third sun gear S3.
3. Third ring gear R3 and third planet carrier P
C3. Note that the first simple planetary gear mechanism G1 forms the first speed change means of the present invention, and the planetary gear train constituted by the second and third simple planetary gear mechanisms G2 and G3 forms the second speed change means of the present invention.

The input shaft N is connected to a first sun gear S
1 and the second sun gear S2 via the first
It is also connected to a second planet carrier PC2 in parallel with the second sun gear S2 via a clutch C1. The second planet carrier PC2 is connected to the third planet carrier PC3 and is connected to the third planet carrier PC3.
Numeral 3 can be fixed to a case K which is a stationary portion via a third brake B3.

The first planet carrier PC1 is connected to a third sun gear S3, and the third sun gear S3 is
It can be fixed to the case K, which is a stationary part, via the second brake B2, and is connected to the second ring gear R2 via the second clutch C2 in an intermittent manner.

Further, the first ring gear R1 can be fixed to the case K which is a stationary part via the first brake B1. The third ring gear R3 is connected to the output shaft U.

In the planetary gear train of the automatic transmission having the above configuration, each clutch C1 and C2 and each brake B1 to B3 are used.
Are selectively operated in the combinations shown in FIG. 2 so that the number of shift stages of six forward speeds and one reverse speed as shown in FIG. 2 can be obtained.

In FIG. 2, a circle indicates a fastened state, and a blank indicates an open state. Α1 represents the ratio of the number of gears of the first sun gear S1 to the number of gears of the first ring gear R1, α2 represents the ratio of the number of gears of the second sun gear S2 to the number of gears of the second ring gear R2, and α3 represents the third number of gears.
The ratio of the number of gears of the third sun gear S3 to the number of gears of the ring gear R3 is shown.

As apparent from FIG. 2, three sets of simple planetary gear mechanisms G1 to G3 and five friction elements C1, C
By combining 2, B1 to B3, the number of shift stages of six forward speeds becomes possible. Moreover, when power is transmitted,
At the commonly used fifth speed, two sets of simple planetary gear mechanisms G1, G
In the third and sixth speeds, only one set of the simple planetary gear mechanism G3 operates, so that gear noise is small and power transmission efficiency is good.

Further, in the planetary gear train of the automatic transmission according to this embodiment, the first ring gear R1 rotates faster than the input shaft N at the first speed, and the third ring gear R3 rotates at the fifth speed and the sixth speed. Although rotating at a higher speed than the input shaft N, other components do not rotate at a higher speed than the input shaft N.

This will be described with reference to the diagram shown in FIG. The diagram in FIG. 3 shows the relationship between the rotational speeds of the components of the simple planetary gear mechanisms G1 to G3. That is, if the rotation speeds of the ring gear, the planet carrier, and the sun gear are NR, NPc, and NS, and (the number of gears of the sun gear) / (the number of gears of the ring gear) is α, NR + α × NS− (1 + α) ) X NPc = 0 holds. Accordingly, the vertical axes indicating the rotational speeds of the ring gear, the planet carrier, and the sun gear are indicated by the R axis and PC
If the ratio of the distance between the PC axis and the R axis to the distance between the PC axis and the S axis is set to α, an arbitrary straight line on this coordinate and the R axis, the PC axis, and the S axis Will satisfy the relationship shown in the above equation. In addition, the vertical axes indicating the components connected to each other in two or more simple planetary gear mechanisms are drawn at the same position. For example, the second and third simple planetary gear mechanisms G2, G
The three planet carriers PC2 and PC3 are coaxial.

Explaining the first speed, FIG. 3A is a diagram showing the state of the first and second second and third simple planetary gear mechanisms G2 and G3. In this case, the second simple planetary gear is used. In the mechanism G2, the second planet carrier PC2 is fixed, so that a point having a rotation speed of 0 is set on the PC shaft, and the second sun gear S2 is integrally connected to the input shaft N so that the second sun gear S2 has a rotation speed of 1 on the S shaft. A point is taken, and an intersection between the straight line connecting these two points and the R axis indicates the rotation speed of the second ring gear R2 with respect to the input shaft N.

Also, in the third simple planetary gear mechanism G2, the third planet carrier PC3 is fixed integrally with the second planet carrier PC2.
And the third sun gear S3 has the same rotational speed as the second ring gear R2 because of the second clutch C2, so that the third sun gear S3 is set at the same point as the second ring gear R2, and a straight line connecting the two points and R
The intersection with the shaft indicates the rotation speed of the third ring gear R3. Since the third ring gear R3 and the output shaft U are integrally connected, the rotation speed of the third ring gear R3 becomes the rotation speed of the output shaft U. Thus, it can be seen from the diagram of FIG. 3 described above that in the first speed, the rotation of the output shaft U is decelerated with respect to the rotation of the input shaft N.

FIGS. 3 (b) to 3 (d) and FIG. 3 (g) show diagrams for the second to fourth speeds and the reverse speed, respectively. As can be seen from these diagrams, it is clear that there is no component rotating at a higher speed than the input shaft N except for the first speed.

Next, the case of the fifth speed will be described. FIG.
(E) shows a diagram of the fifth speed. In this case, since the first clutch C1 and the first brake B1 are operated, the first and third simple planetary gear mechanisms G1 and G3 are operated, and the first sun gear S1 and the third planet carrier PC3 are operated.
Rotates integrally with the input shaft N, and the first ring gear R1
Is fixed, the power from the input shaft N is shifted by the first simple planetary gear mechanism G1 and transmitted to the third sun gear S3. At this time, as shown in the diagram of FIG. 3E, the third ring gear R3 enters an overdrive state in which the third ring gear R3 rotates at a rotation speed higher than the rotation speed of the input shaft N. However, other than the third ring gear R3 integrated with the output shaft U, there is no member that rotates at a higher speed than the input shaft N.

FIG. 3F shows a diagram of the sixth speed. At the sixth speed, only the third simple planetary gear mechanism G3 operates, and similarly to the fifth speed, a member rotating at a higher speed than the input shaft N, except for the third ring gear R3 integrated with the output shaft U. Does not exist.

Next, a second embodiment will be described. FIG. 4 is a view showing a second embodiment of the present invention. In this embodiment, the second sun gear S2 is directly connected to the input shaft N without passing through the first sun gear S1, and the first clutch S3 is connected to the input shaft N in parallel with the second sun gear S2. The first ring gear R1 is directly fixed to the case K, which is a stationary portion, while being intermittently connected via the first ring gear R1. Other configurations and operations are the same as those of the first embodiment. With this configuration, the same effects as those of the first embodiment can be obtained.

The operation of the first brake B1 of the first embodiment is performed by the third clutch C3. In FIG. 2, the friction element B1 becomes C3. Next, a third embodiment will be described. FIG. 5 is a view showing a third embodiment of the present invention.

In this embodiment, the first ring gear R1 is directly fixed to the case K, which is a stationary portion, without going through a brake, and instead, the first planet carrier PC1 and the third sun gear S
3 is intermittently connected via a third clutch C3. Other configurations and operations are the same as those of the first embodiment. With this configuration, the same effects as those of the first embodiment can be obtained.

The operation of the first brake B1 of the first embodiment is performed by the third clutch C3, and in FIG. 2, the friction element B1 becomes C3. Next, a fourth embodiment will be described. FIG. 6 is a diagram showing a fourth embodiment of the present invention.

In this embodiment, the second sun gear S2 is directly connected to the input shaft N without passing through the first sun gear S1, and the second sun gear S2 is connected to the first simple planetary gear mechanism G1.
2 in parallel with the first ring gear R1 and the input shaft N,
The first planet carrier PC1 is connected to a third sun gear S3 via a third clutch C3, and the first sun gear S1 is fixed to a case K which is a stationary portion. Other configurations are the same as those of the first embodiment.

Even if the first simple planetary gear mechanism G1 as the first speed change means is constructed in this manner, the same effect as that of the first embodiment can be obtained. The operation of the first brake B1 of the first embodiment is performed by the third clutch C3, and a speed ratio of six forward speeds as shown in FIG. 7 is obtained.

Next, a fifth embodiment will be described. FIG. 8 is a view showing a fifth embodiment of the present invention. This embodiment employs a double pinion type simple planetary gear mechanism for the first simple planetary gear mechanism G1 of the first embodiment, fixes the first planet carrier PC1 to the case K which is a stationary part, and 1
The ring gear R1 is intermittently connected to the third sun gear S3 via a third clutch C3. Other configurations are the same as those of the first embodiment.

Even if the first simple planetary gear mechanism G1 as the first speed change means is constructed in this manner, the same effect as that of the first embodiment can be obtained. The operation of the first brake B1 of the first embodiment is performed by the second clutch C2, and a speed ratio of six forward speeds as shown in FIG. 9 is obtained.

The first speed change means is not limited to the first simple planetary gear mechanism G1 of the present embodiment, but may employ another known mechanism. In addition, a one-way clutch may be provided in parallel with each of the friction elements to facilitate shift control.

When a torque converter is provided between the planetary teeth and the engine, as shown in FIG.
A lock-up clutch T connects the input shaft T1 of the torque converter T to the second and third planet carriers PC2 and PC3.
2 so that the turbine liner T3 of the torque converter T and the second sun gear S2 can be connected or connectable with each other through five friction elements including the lock-up clutch T2 of the torque converter T. Can be configured. In this case, in the fourth speed and the fifth speed, a part of the power is transmitted without passing through the torque converter T, resulting in a so-called power split transmission. In the sixth speed, all the power is transmitted without passing through the torque converter T. Is done.

[0041]

As described above, the planetary gear train of the automatic transmission according to the present invention has two sets of simple planetary gear mechanisms and another set of first speed change means such as a simple planetary gear, and five sets of simple planetary gears. With the friction element, there is an effect that the number of shift stages of six forward speeds can be obtained.

Further, when a set of simple planetary gear mechanisms is applied as the first speed change means, the number of simple planetary gear mechanisms that operate by power transmission is two in the commonly used fifth gear and only one in the sixth gear. Because of the small number, the gear noise is small, the power transmission efficiency is high, and in addition to the third ring gear connected to the output shaft, it rotates at a higher speed than the input shaft at the commonly used fifth and sixth speeds. There is also an effect that no member exists.

[Brief description of the drawings]

FIG. 1 is a schematic skeleton diagram showing a planetary dentition of an automatic transmission according to a first embodiment.

FIG. 2 is a table showing combinations of operating elements in a planetary gear train of the automatic transmission according to the first embodiment and gear ratios thereof.

FIG. 3 is a diagram showing a relationship between rotation speeds of respective components of the simple planetary gear mechanism.

FIG. 4 is a schematic skeleton diagram showing a planetary dentition of an automatic transmission according to a second embodiment.

FIG. 5 is a schematic skeleton diagram showing a planetary dentition of an automatic transmission according to a third embodiment.

FIG. 6 is a schematic skeleton diagram showing a planetary dentition of an automatic transmission according to a fourth embodiment.

FIG. 7 is a table showing combinations of operating elements in a planetary gear train of an automatic transmission according to a fourth embodiment and gear ratios thereof.

FIG. 8 is a schematic skeleton diagram showing a planetary dentition of an automatic transmission according to a fifth embodiment.

FIG. 9 is a table showing combinations of operating elements in a planetary gear train of an automatic transmission according to a fifth embodiment and gear ratios thereof.

FIG. 10 is a schematic skeleton diagram showing a planetary dentition of an automatic transmission according to a sixth embodiment.

[Explanation of symbols]

 N input shaft U output shaft G1 first simple planetary gear mechanism (first transmission means) G2 second simple planetary gear mechanism G3 third simple planetary gear mechanism S1 first sun gear S2 second sun gear S3 third sun gear R1 first ring gear R2 Second ring gear R3 Third ring gear PC1 First planet carrier PC2 Second planet carrier PC3 Third planet carrier B1 First brake B2 Second brake B3 Third brake C1 First clutch C2 Second clutch C3 Third clutch K Case (stationary) Part)

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16H 3/44-3/78

Claims (4)

(57) [Claims] 1. A first transmission unit and a second transmission unit are interposed between an input shaft and an output shaft.
A second simple planetary gear mechanism having a second sun gear, a second ring gear, and a second planet carrier;
The input shaft and the second sun gear are connected or connectable using a planetary gear train including a third ring planetary gear mechanism and a third simple planetary gear mechanism having a third planetary carrier. A planet carrier, and the coupling shaft can be coupled to the input shaft; the second ring gear and the third sun gear can be coupled; and the third sun gear and the third planet carrier can be fixed to the stationary portion, respectively. A planetary gear train for an automatic transmission, wherein a third ring gear is connected to an output shaft, and an input shaft and a third sun gear are connectable via the first transmission means. 2. A first transmission having a first sun gear, a first ring gear, and a first planet carrier as first transmission means.
A simple planetary gear mechanism is provided, the first sun gear of which can be connected or connectable to the input shaft, the first planet carrier is connected to the third sun gear, and the first ring gear can be fixed to the stationary part. Claim 1 characterized by the following:
3. The planetary gear train of the automatic transmission according to claim 1. 3. A first transmission having a first sun gear, a first ring gear, and a first planet carrier as first transmission means.
A simple planetary gear mechanism is provided, the first ring gear of which is connected or connectable to an input shaft, the first planet carrier is connectable to a third sun gear, and the first sun gear is fixed to a stationary portion. The planetary gear train of the automatic transmission according to claim 1. 4. A double-pinion type first simple planetary gear mechanism having a first sun gear, a first ring gear, and a first planet carrier is provided as a first transmission means, and
2. The automatic transmission according to claim 1, wherein the sun gear is connected or connectable to the input shaft, the first ring gear is connectable to the third sun gear, and the first planet carrier is fixed to the stationary part. Planetary gear train.