KR101305640B1 - 8-speed power train of automatic transmission - Google Patents

Abstract

PURPOSE: An 8-speed power train of an automatic transmission improves fuel efficiency by forming a gear shift stage with forward 8-speed and backward 1-speed. CONSTITUTION: A first line gear (S1) is selectively connected to a second line gear through a first clutch (CL1). A first ring gear (R1) is always connected to a transmission case. A second ring gear is selectively connected to the first line gear through a second clutch. A second planetary carrier (PC2) is selectively connected to an input shaft through a third clutch. A third line gear is directly connected to the second planetary carrier, and a third ring gear is directly connected to the second line gear. A third planetary carrier (PC3) is selectively connected to the input shaft through a fourth clutch. A fourth line gear is directly connected to the second line gear and the third ring gear. A fourth ring gear (R4) is directly connected to the third planetary carrier.

Description

8-speed power train of automatic transmission {8-SPEED POWER TRAIN OF AUTOMATIC TRANSMISSION}

The present invention relates to a power train of an automatic transmission, and more particularly, to an eight speed power train of an automatic transmission that implements a forward eight speed reverse one speed.

In general, a multi-stage shifting mechanism of an automatic transmission is implemented by combining a plurality of planetary gear sets, and a power train in which the plurality of planetary gear sets is combined receives torque from a torque converter included in the automatic transmission and shifts it to the output shaft. It will serve to deliver.

However, the more transmission stages that can be implemented in transmission, the more appropriate transmission ratio can be designed, and the vehicle can be realized in terms of power performance and fuel efficiency. Therefore, an automatic transmission that implements more transmission stages is of interest for continuous research. have.

In addition, even if the same number of gear stages are implemented, the durability, power transmission efficiency, size, etc. of the powertrain are changed according to the combination method of the planetary gear set, thereby inventing a more robust, no power loss, and a compact powertrain configuration. Efforts are always underway.

In particular, unlike a manual transmission in which the driver has to shift frequently when there are too many shift stages, the automatic transmission performs transmission by controlling the operation of the power train by the transmission control unit according to the driving condition. Efforts have been made to find a configuration of a powertrain that can implement many shift stages.

From this point of view, the four-speed and five-speed automatic transmissions are the mainstream automatic transmissions currently used, but recently, six-speed automatic transmissions have been developed and applied to vehicles, while improving power transmission performance and fuel economy. The development of an automatic transmission of 8 speeds or more that can reduce the speed is required.

Therefore, the present invention was created to solve the above problems, and an object of the present invention is to provide an eight-speed power train of an automatic transmission that implements eight forward and one reverse speed.

The eight-speed power train of the automatic transmission according to the embodiment of the present invention for achieving this object is a first planetary gear set, a second sun gear, a second ring gear consisting of a first sun gear, a first ring gear and a first planet carrier. And a third planetary gear set comprising a second planetary carrier, a third sun gear, a third ring gear, and a third planetary gear set consisting of a third planetary carrier and a fourth sun gear, a fourth ring gear, and a fourth planetary carrier. 4. A powertrain of an automatic transmission comprising a planetary gear set, wherein the first sun gear is selectively connected to the second sun gear through a first clutch, and the first ring gear is always fixedly connected to the transmission case. The first planet carrier is fixedly connected to the input shaft, the second ring gear is selectively connected to the first sun gear via a second clutch, and the second planet carrier is connected to the third clutch. And the third sun gear is directly connected to the second planetary carrier, the third ring gear is directly connected to the second sun gear, and the third planet carrier is connected to the input shaft through a fourth clutch. And optionally connected to the fourth sun gear, directly connected to the second sun gear and the third ring gear, the fourth ring gear is directly connected to the third planet carrier, and the fourth planet carrier is directly connected to the output shaft. It is done.

In addition, the eight-speed powertrain of the automatic transmission according to another embodiment of the present invention is a first planetary gear set, a second sun gear, a second ring gear and a second planetary gear set comprising a first sun gear, a first ring gear and a first planet carrier. A second planetary gear set consisting of a planet carrier, a third sun gear, a third ring gear, and a third planet gear set having a double pinion structure composed of a third planet carrier;

In a powertrain of an automatic transmission comprising a fourth planetary gear set comprising a fourth sun gear, a fourth ring gear, and a fourth planetary carrier, the first sun gear is selectively connected to the second sun gear through a first clutch. The first ring gear is always fixedly connected to the transmission case, the first planet carrier is fixedly connected to the input shaft, the second sun gear is directly connected to the third planet carrier, and the second ring gear is the second clutch. Selectively connected to the first sun gear via the second planetary carrier, the second planetary carrier is selectively connected to the input shaft via a third clutch, the third sun gear is directly connected to the second planetary carrier, and the third ring gear Is directly connected to the fourth ring gear, a third planet carrier is directly connected to the second sun gear, and the fourth sun gear is directly connected to the second sun gear and the third planet carrier, 4, the ring gear is selectively connected to the input shaft via a first clutch in a state of direct connection with the third ring gear and the fourth planet carrier may be configured to be directly connected to the output shaft.

In addition, a brake may be further included to restrain rotation of the second sun gear and the fourth sun gear.

As described above, according to the eight-speed power train of the automatic transmission according to the present invention, by using four planetary gear sets, four clutches and one brake, the eighth forward speed and the first reverse speed are implemented to realize power transmission performance. It has the effect of improving and improving fuel economy.

1 is a block diagram of an eight-speed power train of an automatic transmission according to an embodiment of the present invention.
2 is an operation table for operating an eight-speed power train of an automatic transmission according to an embodiment of the present invention.
FIG. 3 is a lever analysis diagram illustrating a relationship between a speed ratio between eight forward speeds and one reverse speed implemented by an eight-speed power train of an automatic transmission according to an embodiment of the present invention.
4 is a configuration diagram of an eight-speed power train of an automatic transmission according to another embodiment of the present invention.

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

1 is a block diagram of an eight-speed power train of an automatic transmission according to an embodiment of the present invention. As shown in FIG. 1, an eight-speed power train of an automatic transmission according to an embodiment of the present invention includes an input shaft 10, an output shaft 20, a transmission case 30, and a first planetary gear set disposed on the same axis. PG1, second planetary gear set PG2, third planetary gear set PG3, fourth planetary gear set PG4, first clutch CL1, second clutch CL2, third clutch CL3 ), A fourth clutch CL4 and a brake BK.

The first planetary gear set PG1, the second planetary gear set PG2, the third planetary gear set PG3, and the fourth planetary gear set PG4 are sequentially disposed on the same axis from the engine side to form an input shaft ( The rotational power of the engine transmitted from 10) is shifted and output to the output shaft 20.

The input shaft 10 refers to a turbine shaft of the torque converter as an input member, which is input while the rotational power from the engine crankshaft is converted into torque through the torque converter, and is not shown via the output shaft 20 as an output member. One known differential is used to drive the drive wheels.

The first, second, third, and fourth planetary gear sets PG1, PG2, PG3, and PG4 are formed of a simple planetary gear set. The first planetary gear set PG1 is a single pinion planetary gear set. (S1), a first planet carrier PC1 supporting the first pinion P1 circumscribed to the first sun gear S1, and a first ring gear R1 in which the first pinion P1 is inscribed. It includes three operating elements consisting of.

The second planetary gear set PG2 is a single pinion planetary gear set, and includes a second sun gear S2 and a second planet carrier PC2 that supports the second pinion P2 circumscribed to the second sun gear S2. ) And three actuating elements consisting of a second ring gear R2 in which the second pinion P2 is inscribed.

The third planetary gear set PG3 is a single pinion planetary gear set, and includes a third sun gear S3 and a third planet carrier PC3 that supports the third pinion P3 external to the third sun gear S3. ) And three operating elements consisting of a third ring gear R3 in which the third pinion P3 is inscribed.

The fourth planetary gear set PG4 is a single pinion planetary gear set, and includes a fourth sun gear S4 and a fourth planet carrier PC4 supporting a fourth pinion P4 circumscribed to the fourth sun gear S4. ) And a fourth ring gear R4 in which the fourth pinion P4 is inscribed.

2 is an operation table for operating an eight-speed power train of an automatic transmission according to an embodiment of the present invention. Referring to Figure 2, it can be seen that the friction member, that is, the clutch and the brake applied to the eight-speed power train of the automatic transmission according to an embodiment of the present invention operates in each shift stage.

That is, the third clutch CL3 and the brake BK operate at the first forward speed,

At the second forward speed, the second clutch CL2 and the brake BK operate.

The fourth clutch CL4 and the brake BK operate at the third forward speed,

The second clutch CL2 and the fourth clutch CL4 operate at the fourth forward speed,

The third clutch CL3 and the fourth clutch CL4 operate at five forward speeds,

The first clutch CL1 and the fourth clutch CL4 operate at six forward speeds,

The first clutch CL1 and the third clutch CL3 operate at seven forward speeds,

The first clutch CL1 and the second clutch CL2 operate at eight forward speeds,

The shift is performed while the second clutch CL2 and the third clutch CL3 are operated in the reverse direction.

3 is a lever analysis diagram showing a speed ratio relationship between eight forward speeds and one reverse speed implemented by an eight-speed power train of an automatic transmission according to an embodiment of the present invention. Referring to Figure 3, it can be seen visually the shifting process of the eight-speed power train of the automatic transmission according to an embodiment of the present invention. Here, the vertical line is sequentially set from the left to the first operating element (N1) to the eighth operating element (N8), the operating element of the first, second, third, fourth planetary gear set (PG1, PG2, PG3, PG4) It depends on each gear ratio (number of teeth of sun gear / number of rings).

Positioning of each operating element in the shift diagram as described above is well known to those skilled in the art of the powertrain, so a detailed description thereof will be omitted.

[1st speed forward]

In the forward 1 speed, as shown in FIG. 2, the third clutch CL3 and the brake BK are operated and controlled.

That is, as shown in FIG. 3, when the input is made to the first planet carrier PC1, which is the second operating element N2, the second clutch, which is the fifth operating element N5, is operated by the operation of the third clutch CL3. The planet carrier PC2 and the third sun gear S3 are rotated at constant speed, and the second sun gear S2, the third ring gear R3, and the eighth operating element N8 are operated by the brake BK. 4 Sun gear (S4) is to operate as a fixed element. Accordingly, the rotational power of the first forward speed is realized through the fourth planet carrier PC4 of the fourth planetary gear set PG4 having the constant deceleration output.

[2 speed forward]

At the second forward speed, as shown in FIG. 2, the second clutch CL2 and the brake BK are operated and controlled.

That is, as shown in FIG. 3, the first sun gear S1, which is the third operating element N3, and the second ring gear R2, which is the fourth operating element N4, rotate at a constant speed. Element, and the second sun gear S2, the third ring gear R3, and the fourth sun gear S4, which are the eighth operating element N8, are operated as the fixed element by the operation of the brake BK. . Therefore, the rotational power of the second forward speed is realized through the fourth planetary carrier PC4 of the fourth planetary gear set PG4 having the constant deceleration output.

[3 speed forward]

At the third forward speed, as shown in FIG. 2, the fourth clutch CL4 and the brake BK are operated and controlled.

That is, as shown in FIG. 3, the third planet carrier PC3 and the fourth ring gear R4, which are the sixth operating element N6, are directly connected to the input shaft 10 by the operation of the fourth clutch CL4. The second sun gear S2, the third ring gear R3, and the fourth sun gear S4, which are the eighth operating element N8, are operated as the fixed element by the operation of the brake BK. Through the fourth planet carrier PC4 of the fourth planetary gear set PG4, rotational power of three forward speeds is realized.

[4 forward speed]

At 4th forward speed, as shown in FIG. 2, the 2nd clutch CL2 and the 4th clutch CL4 are operationally controlled.

That is, as shown in FIG. 3, the third planet carrier PC3 and the fourth ring gear R4, which are the sixth operating element N6, are directly connected to the input shaft 10 by the operation of the fourth clutch CL4. The rotational power input through the first planet carrier PC1, which is the second operating element N2, is transmitted to the second clutch CL2 at a speed ratio increased via the first sun gear S1, which is the third operating element N3. By output to the second ring gear (R2) that is the fourth operating element (N4), the rotational power of the fourth forward speed is realized through the fourth planetary carrier (PC4) of the fourth planetary gear set (PG4) that is always decelerated output do.

[5th forward]

At the 5th forward speed, as shown in FIG. 2, the third clutch CL3 and the fourth clutch CL4 are controlled to operate.

That is, as shown in FIG. 3, the first planet carrier PC1 and the fifth actuating element N5, which are the second actuating element N2, are operated by the third clutch CL3 and the fourth clutch CL4. 2 The planetary carrier PC2, the third planet carrier PC3 as the sixth operating element N6 and the third ring carrier R4 and the third planet carrier PC3 as the seventh operating element N7 are directly connected. 2 Since the operating element N2, the fifth operating element N5, the sixth operating element N6, and the seventh operating element N7 all rotate at constant speed, the rotational power of the fifth forward speed through the fourth planet carrier PC4 is Is implemented.

[6th forward]

At 6th forward speed, as shown in FIG. 2, the 1st clutch CL1 and the 4th clutch CL4 are operationally controlled.

That is, as shown in FIG. 3, the third planet carrier PC3 and the fourth ring gear R4, which are the sixth operating element N6, are directly connected to the input shaft 10 by the operation of the fourth clutch CL4. The second sun gear S2, the third ring gear R3, and the fourth sun gear S4 of which the first sun gear S1 of the first planetary gear set PG1, which is always at the speed increase output, is the eighth operating element N8. Since the increased rotational power is inputted through the fourth planetary carrier PC4 of the fourth planetary gear set PG4 which is always decelerated, the rotational power of six forward speeds is realized.

[7th forward]

At 7th forward speed, as shown in FIG. 2, the 1st clutch CL1 and the 3rd clutch CL3 are operationally controlled.

That is, as shown in FIG. 3, the second planet carrier PC2 and the third sun gear S3, which are the fifth operating element N5, are directly connected to the input shaft 10 by the operation of the third clutch CL3. The second sun gear S2 and the third ring gear whose rotational power is increased by the first sun gear S1 of the first planetary gear set PG1 by the operation of the first clutch CL1 are the eighth operating elements N8. Since it is output to R3) and the fourth sun gear S4, the rotational power of the seventh forward speed is realized through the fourth planetary carrier PC4 of the fourth planetary gear set PG4 which is always decelerated.

[8th forward]

At 8th forward speed, as shown in FIG. 2, the 1st clutch CL1 and the 2nd clutch CL2 are operationally controlled.

That is, as shown in FIG. 3, the first sun gear whose power is input to the first planet carrier PC1, which is the second actuation element N2, by the operation of the second clutch CL2, is the third actuation element N3. The second sun gear (8) is input to the second ring gear (R2), which is the fourth operating element (N4), by the increased rotational power via S1), and the eighth operating element (N8), by the operation of the first clutch (CL1). S2), the third ring gear (R3) and the fourth sun gear (S4) is in direct rotation with the fourth operating element (N4) is rotated through the fourth planet carrier (PC4) which is the seventh operating element (N7) Eight-speed rotational power is realized.

[apse]

In the reverse shift stage, as shown in FIG. 2, the second clutch CL2 and the third clutch CL3 are controlled to operate.

That is, as shown in FIG. 3, the first sun gear whose rotational power input to the first planet carrier PC1, which is the second actuation element N2, by the operation of the second clutch CL2 is the third actuation element N3. The second planetary carrier PC2 which is increased through the S1 and is input to the second ring gear R2, which is the fourth operating element N4, and is operated by the third clutch CL3, which is the fifth operating element N5. ) And the third sun gear S3 are directly connected to the input shaft 10, so that the reverse shift is realized through the fourth planet carrier PC4 of the fourth planetary gear set PG4 having constant deceleration output.

4 is a configuration diagram of an eight-speed power train of an automatic transmission according to another embodiment of the present invention. As shown in FIG. 4, the eight-speed power train of the automatic transmission according to another embodiment of the present invention applies the third planetary gear set PG3 as a double pinion planetary gear set.

Here, the friction member operates as shown in FIG. 2 except that the sixth operating element is changed to the third ring gear and the fourth ring gear, and the eighth operating element is changed to the second sun gear, the third planet carrier, and the fourth sun gear. And, in the shift process is made to the same principle as shown in Figure 3, the detailed description thereof will be omitted.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, And all changes to the scope that are deemed to be valid.

10: input shaft
20: output shaft
30: transmission case
PG1: 1st planetary gear set
PG2: 2nd Planetary Gear Set
PG3: Third Planetary Gear Set
PG4: 4th Planetary Gear Set
CL1: First clutch
CL2: second clutch
CL3: third clutch
CL4: fourth clutch
BK: brake
S1: first sun gear
S2: 2nd Sun Gear
S3: third sun gear
S4: 4th Sun Gear
R1: first ring gear
R2: second ring gear
R3: third ring gear
R4: 4th ring gear
PC1: first planet carrier
PC2: second planetary carrier
PC3: Third Planetary Carrier
PC4: fourth planetary carrier
P1: first pinion
P2: second pinion
P3: third pinion
P4: fourth pinion

Claims (3)

A first planetary gear set comprising a first sun gear, a first ring gear, and a first planetary carrier;
A second planetary gear set comprising a second sun gear, a second ring gear, and a second planetary carrier;
A third planetary gear set including a third sun gear, a third ring gear, and a third planetary carrier; And
In the powertrain of an automatic transmission comprising a fourth planetary gear set comprising a fourth sun gear, a fourth ring gear and a fourth planetary carrier,
The first sun gear is selectively connected to the second sun gear through a first clutch, the first ring gear is always fixedly connected to the transmission case, the first planet carrier is fixedly connected to the input shaft, and the second ring The gear is selectively connected to the first sun gear via a second clutch, the second planet carrier is selectively connected to the input shaft via a third clutch, and the third sun gear is directly connected to the second planet carrier, A third ring gear is directly connected to the second sun gear, the third planet carrier is selectively connected to the input shaft via a fourth clutch, and the fourth sun gear is directly connected to the second sun gear and the third ring gear, The fourth ring gear is directly connected to the third planet carrier, and the fourth planet carrier is directly connected to the output shaft. A first planetary gear set comprising a first sun gear, a first ring gear, and a first planetary carrier;
A second planetary gear set comprising a second sun gear, a second ring gear, and a second planetary carrier;
A third planetary gear set having a double pinion structure including a third sun gear, a third ring gear, and a third planet carrier; And
In the powertrain of an automatic transmission comprising a fourth planetary gear set comprising a fourth sun gear, a fourth ring gear and a fourth planetary carrier,
The first sun gear is selectively connected to the second sun gear through a first clutch, the first ring gear is always fixedly connected to a transmission case, the first planet carrier is fixedly connected to an input shaft, and the second sun gear Is directly connected to the third planet carrier, the second ring gear is selectively connected to the first sun gear through a second clutch, and the second planet carrier is selectively connected to the input shaft through a third clutch, The third sun gear is directly connected to the second planetary carrier, the third ring gear is directly connected to the fourth ring gear, the third planet carrier is directly connected to the second sun gear, and the fourth sun gear is the second Directly connected to the sun gear and the third planet carrier, the fourth ring gear is selectively connected to the input shaft via a fourth clutch in a state directly connected to the third ring gear, and the fourth planet carrier The rear 8-speed power train of the automatic transmission, characterized in that directly connected to the output shaft. 3. The method according to claim 1 or 2,
The eight-speed power train of the automatic transmission, characterized in that the brake is further included to restrain the rotation of the second sun gear and the fourth sun gear.

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