KR100803303B1 - A 8th-speed power train of an automatic transmission - Google Patents

Abstract

An 8-speed power train of an automatic transmission is provided to decrease a speed shifting time by changing only one of two or three operation elements during a speed shifting process. A single pinion planetary gear set(SPG) includes a first linear gear, a first planetary carrier, and a first ring gear. A Ravigneaux gear set(RG) includes second and third linear gears, second to fourth planetary carriers, and second and third ring gears. The second linear gear is connected to the first planetary carrier through a second clutch. The fourth planetary carrier is gear-coupled with the second linear gear and connected to a case through a first one-way clutch and a second brake. The third linear gear is gear-coupled with the second and third planetary carriers. The second and third ring gears are gear-coupled with the second and third planetary carriers and connected to the case through the second brake. A double pinion planetary gear set(DPG) includes a fourth linear gear, fifth and sixth planetary carriers, and a fourth ring gear. The fifth and sixth planetary carriers are gear-coupled with the fourth linear gear and directly connected to the second and third planetary carriers. The fourth ring gear is gear-coupled with the fifth and sixth planetary carriers and directly connected to an output shaft.

Description

8th speed train of automatic transmission {A 8TH-SPEED POWER TRAIN OF AN AUTOMATIC TRANSMISSION}

1 is a schematic diagram showing a conventional six-speed powertrain.

Figure 2 is a table of the operation element of the conventional six-speed powertrain.

3 is a schematic diagram showing an eight-speed powertrain according to the present invention;

Figure 4 is a table of the operating elements of the eight-speed powertrain according to the present invention.

Figure 5 is a graph of the relationship between the operating element and the speed of the eight-speed powertrain according to the present invention.

※ Explanation of symbols about main part of drawing ※

1 case 2 output shaft

3: input shaft B1: first brake

B2: 2nd brake C1: 1st clutch

C2: Second Clutch C3: Third Clutch

DPG: Double pinion planetary gear set F1: 1st one-way clutch

PC1: 1st planetary carrier PC2: 2nd planetary carrier

PC3: 3rd planetary carrier PC4: 4th planetary carrier

PC5: 5th planetary carrier PC6: 6th planetary carrier

R1: first ring gear R2: second ring gear

R3: 3rd Ring Gear R4: 4th Ring Gear

RG: Avenue gear set S1: First sun gear

S2: Second Sun Gear S3: Third Sun Gear

S4: 4th Sun Gear SPG: Single Pinion Planetary Gear Set

The present invention relates to an eight-speed power train of an automatic transmission, and more particularly, to an eight-speed power train of an automatic transmission for a vehicle capable of implementing a shift stage of eight forward speeds and one reverse speed.

In general, a vehicle is provided with an automatic transmission capable of automatically controlling the traveling speed of the vehicle, and the multi-speed transmission mechanism of the automatic transmission consists of a combination of a plurality of planetary gear sets.

When a plurality of planetary gear sets are combined, the power train performs a function of shifting the multi-stage transmission to the output side when rotation power is input from a torque converter that converts and transmits engine torque.

Since the power train of the automatic transmission has more shift stages, it is advantageous in terms of power performance and fuel consumption rate, and thus, a power train capable of implementing more shift stages is required.

Also, even if the same number of gear stages are implemented, durability, power transmission efficiency, size and weight vary greatly depending on the combination method of the planetary gear set. Therefore, the power train can be more robust and compact while minimizing power loss. Efforts for development are ongoing.

In developing a power train using planetary gear sets, rather than developing any new planetary gear sets, a combination of existing single pinion planetary gear sets, double pinion planetary gear sets, or single and double pinion planetary gear sets The combination of a planet type planetary gear set and the accompanying clutches, brakes, and one-way clutches can be arranged at any position to achieve the desired speed and the gear ratio without any power loss. Various studies are aimed at improving the target.

In particular, in the case of a manual transmission, if there are too many shift stages, the driver should shift frequently. However, in the case of an automatic transmission, the transmission control unit automatically controls the operation of the power train in accordance with the driving state to change the shift. As a practice, developing a power train that can implement more shifts is of great value.

In order to cope with this trend, various studies on the 4th and 5th speed power trains are being conducted, and recently, the power train of the automatic transmission that can realize the 6th forward and 1st speed shift stages has been developed.

As an example, as shown in FIG. 1, three single pinion planetary gear sets SPG1, SPG2 and SPG3 are combined from the front to the rear, and the first sun gear S1 of the first single pinion planetary gear set SPG1 is Variablely fixed to the transmission case 1 through the first brake B1, the first planet carrier PC1 is fixedly connected to the third ring gear R3 of the third single-pinion planetary gear set SPG3. Low output gear (OUT) is installed to operate as an output element.

In addition, the first ring gear R1 of the first single pinion planetary gear set SPG1 is directly connected to the second planet carrier PC2 of the second single pinion planetary gear set SPG2.

The second sun gear S2 of the second single pinion planetary gear set SPG2 is directly connected to the input shaft 3, and the second ring gear R2 is the third of the third single pinion planetary gear set SPG3. It is directly connected to the planet carrier PC3.

Here, the second ring gear R2 and the third planet carrier PC3 are variably connected to the input shaft 3 through the second clutch C2, and at the same time, the transmission case 1 through the second brake B2. Is fixed variably).

In addition, the third sun gear S3 of the third single pinion planetary gear set SPG3 is variably connected to the input shaft 3 through the first clutch C1, and at the same time, the transmission case is connected through the third brake B3. It is fixedly fixed to (1).

In this power train, as shown in FIG. 2, the first brake B1 and the second brake B2 operate at the first forward speed, and the first brake B1 and the third brake B3 operate at the second forward speed. The first brake B1 and the first clutch C1 operate at the third forward speed, and the first brake B1 and the second clutch C2 operate at the fourth forward speed, and the first and second clutch C1 at the fifth forward speed. (C2) is operated, the second clutch (C2) and the third brake (B3) operate at the forward 6 speed, and the first clutch (C1) and the second brake (B2) operate at the forward 1 speed, the forward 6 This will realize the gearshift of the speed 1 and the speed 2 reverse.

In the power train as described above, the first, second, and third ring gears R1, R2, and R3 are connected to the second, third, and first planet carriers PC2, PC3, and PC1, respectively. There is a disadvantage in that the total length of the automatic transmission is separated, which causes a problem that a lot of the transmission weight.

In addition, the output gear 2 is connected to the first planetary carrier PC1 to increase its working torque, thereby causing a problem of reducing the durability of the planetary carrier.

In addition, since the shift stage is limited to six speeds in the related art, there is a limit to improving power performance and fuel consumption rate.

The present invention has been invented to solve the above problems, the object of which is to implement a double-pinion planetary gear set, a single pinion planetary gear set and a lave gear set to implement a shift speed of 8 forward speed and 1 reverse speed. The present invention provides an eight-speed power train of an automatic transmission that can improve a shifting feeling and shorten a shift time while driving a vehicle, and minimize impact force when a skip shift occurs in which the speed of a vehicle is drastically reduced.

Referring to the characteristic configuration of the present invention for achieving the above object is as follows.

The eight-speed power train of the automatic transmission according to the present invention includes a first sun gear connected directly to the case, a first planet carrier geared to the first sun gear, and a first ring gear coupled to the first planet carrier and directly connected to the input shaft. Single pinion planetary gear set consisting of gears; A second sun gear connected to the first planetary carrier via a second clutch, a fourth planet carrier geared to the second sun gear and connected to the case via a first one-way clutch and the first brake, and the fourth A second planetary carrier and a third planetary carrier coupled to and directly connected to the planetary carrier; a third sun gear geared to the second planetary carrier and the third planetary carrier; and the second planetary carrier and the third planetary carrier. A rev gear set comprising a second ring gear and a third ring gear which are gear-coupled and connected to the case via a second brake; And a fourth sun gear connected directly to the third sun gear and connected to an input shaft via a first clutch, and gear-coupled to the fourth sun gear and directly connected to a second planetary carrier and a third planet carrier, and simultaneously carrying a third clutch. And a double pinion planetary gear set including a fifth planetary carrier and a sixth planetary carrier connected to the furnace input shaft, and a fourth ring gear connected to the output shaft and directly geared to the fifth planetary carrier and the sixth planetary carrier.

Referring to the present invention having such characteristics in detail as follows.

Figure 3 is a schematic diagram showing an eight speed power train according to the present invention, Figure 4 is an operating element table of the eight speed power train according to the present invention, Figure 5 is a diagram of the operating elements and speed of the eight speed power train according to the present invention. Relationship graph.

As referred to herein, the present invention allows the single pinion planetary gear set (SPG), the rev gear gear set (RG) and the double pinion planetary gear set (DPG) to be connected to the case 1 via a plurality of clutches and brakes. It is installed sequentially.

The single pinion planetary gear set SPG is provided with a first sun gear S1 directly connected to the case 1, and a first planet carrier PC1 is gear-coupled to the first sun gear S1.

The first ring gear R1 is gear-coupled to the first planetary carrier PC1, and the first ring gear R1 is directly connected to the input shaft 3.

The second gear set RG is provided with a second sun gear S2 connected to the first planetary carrier PC1 via a second clutch C2, and the second sun gear S2 has a fourth planet carrier. PC4 is gear-coupled, but the fourth planetary carrier PC4 is connected to the case 1 via the first one-way clutch F1 and the first brake B1.

On the other hand, the second planetary carrier (PC4) and the second planetary carrier (PC2) and the third planetary carrier (PC3) is coupled directly and at the same time connected directly, the second planetary carrier (PC2) and the third planetary carrier ( The third sun gear S3 is gear-coupled to PC3).

In addition, a second ring gear R2 and a third ring gear R3 are gear-coupled to the second planetary carrier PC2 and the third planetary carrier PC3, and the second ring gear R2 and the first The three ring gear R3 is connected to the case 1 via the second brake B2.

The double pinion planetary gear set DPG is provided with a fourth sun gear S4 connected directly to the third sun gear S3 and connected to the input shaft 3 via the first clutch C1, and the fourth sun gear ( In S4), the fifth planetary carrier PC5 and the sixth planetary carrier PC6 are gear-coupled.

The fifth planetary carrier PC5 and the sixth planetary carrier PC6 are directly connected to the second planetary carrier PC2 and the third planetary carrier PC3 and at the same time through the third clutch C3. Is connected to.

A fourth ring gear R4 is gear-coupled to the fifth planetary carrier PC5 and the sixth planetary carrier PC6, and the fourth ring gear R4 is directly connected to the output shaft 2. .

Referring to the present invention configured as described in detail as follows.

As shown in FIGS. 4 and 5, the rotational force of the power input through the input shaft 3 may include the first clutch C1, the second clutch C2, the third clutch C3, the first brake B1, and the first clutch. The output shaft 2 is shifted at a speed of 8 forward speeds and 1 reverse speed by any two or three operations of an operating element consisting of two brakes B2, a third brake B3, and a first one-way clutch F1. ) Is output through

First, the second clutch C2 and the first brake B1 are operated when the output is performed at the reverse 1 speed, and the first clutch C1, the first brake B1 and the first clutch C1 are operated when the output is performed at the forward 1 speed. The first one-way clutch F1 is operated, and when output at the second forward speed, the first clutch C1 and the second brake B2 are operated.

On the other hand, when output at the 3rd forward speed, the first clutch C1 and the third brake B3 are operated, and when output at the 4th forward speed, the first clutch C1 and the second clutch C2 are The first clutch C1 and the third clutch C3 are operated when output at the fifth forward speed.

When the sixth forward speed is output, the second clutch C2 and the third clutch C3 are operated. When the seventh forward speed is output, the third clutch C3 and the third brake B3 are operated. The third clutch C3 and the second brake B2 are operated when output at the eighth forward speed.

As described above, when shifting from the forward 1 speed state to the forward 1 speed state or when shifting from the 1st forward speed to the 8th forward speed, any one of two or three operating elements in each shift section is kept in operation and the other By changing the shift section, the shift time can be shortened, as well as to improve the transmission feeling transmitted to the driver.

In addition, during a skip shift operation in which the shift section is changed to two sections due to rapid deceleration while driving the vehicle, any one of the two or three operating elements maintains the operating state and the shift section is changed by the other change so that the vibration is caused by rapid deceleration. This is to be avoided.

Thus, the present invention is to change the speed of any one of the two or three operating elements when shifting from the 1st speed to the 8th forward speed, thereby reducing the shift time and improving the feeling of shifting can provide a comfortable driving environment. Has a unique effect.

In addition, the present invention is to maintain the operating state of any one of the two operating elements during the skip shift due to rapid deceleration while driving the vehicle has a unique effect of minimizing the vibration generated in the automatic transmission to prevent safety accidents in advance have.

Claims (2)

A first sun gear S1 directly connected to the case 1, a first planetary carrier PC1 geared to the first sun gear S1, and an input shaft 3 Single pinion planetary gear set (SPG) consisting of a first ring gear (R1) directly connected to the; A second sun gear S2 connected to the first planetary carrier PC1 via a second clutch C2, and a first one-way clutch F1 and a second brake gear-coupled to the second sun gear S2; The fourth planetary carrier PC4 connected to the case 1 via (B1), the second planetary carrier PC2 and the third planetary carrier PC3 connected to the fourth planetary carrier PC4 and connected directly at the same time. ), A third sun gear (S3) geared to the second planetary carrier (PC2) and the third planetary carrier (PC3), the gear coupling to the second planetary carrier (PC2) and the third planetary carrier (PC3). A revolve gear set RG having a second ring gear R2 and a third ring gear R3 connected to the case 1 via a second brake B2; And A fourth sun gear S4 connected directly to the third sun gear S3 and connected to the input shaft 3 via a first clutch C1, and gear coupled to the fourth sun gear S4 and having a second planetary carrier ( The fifth planetary carrier PC5 and the sixth planetary carrier PC6 connected directly to the PC2) and the third planetary carrier PC3 and connected to the input shaft 3 via the third clutch C3 and the fifth planetary carrier PC6; Automatic transmission characterized in that it comprises a double pinion planetary gear set (DPG) consisting of a fourth ring gear (R4) geared to the planet carrier (PC5) and the sixth planet carrier (PC6) and directly connected to the output shaft (2). 8-speed powertrain. The 8-speed power train of an automatic transmission according to claim 1, wherein the single pinion planetary gear set (SPG), the rev gear set (RG) and the double pinion planetary gear set (DPG) are sequentially installed.

Images