KR19980046731A - Power train for automatic transmission - Google Patents

Abstract

In order to reduce the number of planetary gear sets and at the same time, to achieve the 5th forward and the 1st reverse speed by using a small number of friction elements, the engine receives the rotational power from the torque converter's turbine and rotates. A double pinion planetary gear set having elements connected variably with the transmission housing to adjust the rotational speed of the output to the input by receiving rotational power of the input shaft, the fixed and variable elements of the double pinion planetary gear set A single pinion planetary gear set having an element connected to the gearbox and an element variablely connected to the transmission housing and outputting a shift according to the power transmitted from the double pinion planetary gear set, and the rotational force of the input shaft described above as a double pinion planetary gear set. Element of a single pinion planetary gear set Clutch means that are variablely installed between each element of the two planetary gear sets to transfer to more elements, one element of the double pinion planetary gear set described above and one of the single pinion planetary gear sets that are variably connected to the clutch means. Variablely installed between the element of the double pinion planetary gear set and the single pinion planetary gear set and the transmission housing to respectively fix one element of the element and the single pinion planetary gear set and the element of the double pinion planetary gear set fixed thereto. And a brake means and other clutch means that are variably installed between the input shaft and the elements of the double pinion planetary gear set so as to transmit the rotational power of the input shaft to one element of the double pinion planetary gear set.

Description

Power train for automatic transmission

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission for a vehicle, and more particularly, to a power train for an automatic transmission that realizes 5 forward speeds and 1 reverse speed by using two simple planetary gear sets.

BACKGROUND ART In general, an automatic transmission for a vehicle includes a transmission control unit (TCU) for automatically controlling a transmission ratio according to a change in a traveling speed and an engine load of a vehicle.

The transmission control unit (TCU) inputs any one of three elements of the planetary gear set (i.e., sun gear, planet carrier, and ring gear) by controlling a plurality of friction elements installed in the gear train in an active or non-operating state. Element, and control the other element as the reaction element to adjust the number of rotation of the output stage.

A power train capable of outputting a transmission ratio of substantially five forward speeds and one reverse speed has at least two planetary gear sets constituting the peripheral speed and one planet gear set constituting the sub transmission, and operates the planetary gear sets. 6 and 7 friction elements are used.

Therefore, such a power train for automatic transmissions uses a lot of planetary gear sets, and thus requires a large number of friction elements, which causes a limitation of miniaturization of automatic transmissions.

Therefore, the present invention has been invented to overcome the above problems, the object of the present invention is to reduce the number of planetary gear sets and at the same time using a small number of friction elements to implement the 5 forward and 1 reverse speed automatic The present invention provides a power train for an automatic transmission capable of miniaturizing a transmission.

A specific object of the present invention is to variably connect the ring gear and the planet carrier of the double pinion planetary gear set to the planet carrier of the single pinion planetary gear set, and to fix the sun gear of the double pinion planetary gear set and the sun gear of the single pinion planetary gear set. By connecting it, it is possible to prevent the rotational elements of the two planetary gear sets at higher speeds than the input shaft or the output shaft at the forward 4 and 5 speeds, thereby providing a power train for the automatic transmission, miniaturizing the automatic transmission and minimizing power loss. It is.

In order to realize this, the power train for an automatic transmission according to the present invention is a transmission housing which receives rotational power of an engine from a turbine of a torque converter and rotates the transmission shaft, and adjusts the number of rotations of the output to the input by receiving the rotational power of the input shaft. A double pinion planetary gear set having elements variably connected thereto, the element being fixed and variably connected to the elements of the double pinion planetary gear set and the element variably connected to the transmission housing and being transmitted from the double pinion planetary gear set. A single-pinion planetary gear set that shifts and outputs according to the power applied, and two planetary gears to transmit the rotational power of the input shaft to one element and more of the single-pinion planetary gear set through the double-pinion planetary gear set. Variable between each element of the set One element of the double pinion planetary gear set described above and one element of the single pinion planetary gear set variably connected to the clutch means and one element of the single pinion planetary gear set and the double pinion planetary gear set fixedly connected thereto Brake means which are variably installed between the elements of the double pinion planetary gear set and the single pinion planetary gear set and the transmission housing to fix one element respectively, and transmit the rotational power of the input shaft to one element of the double pinion planetary gear set. Other clutch means variably installed between the input shaft and the elements of the double pinion planetary gear set.

The power train for the automatic transmission configured as described above automatically or deactivates the clutch means and the brake means to realize the 5th forward and the 1st reverse speed, and at the 4th and 5th forward speeds, the rotational elements of the two planetary gear sets are greater than the input shaft or the output shaft. Prevents rotation at high speed.

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

1 is a configuration diagram of a power train for an automatic transmission according to the present invention.

1 is a configuration diagram of a power train for an automatic transmission according to the present invention, and has a structure in which the torque of the engine E can be converted into torque in the torque converter T to be transmitted to the input shaft 1 of the gear train. .

The input shaft 1 receives torque from the turbine of the torque converter T to transmit torque to the double pinion planetary gear set 3 of the gear train, and the double pinion planetary gear set 3 is a single pinion planetary gear. A clutch hook-up is achieved to transmit the torque shifted to the set 5.

That is, between the ring gear 7 of the double pinion planetary gear set 3 and the planetary carrier 11 on which the pinion gear 9 of the single pinion planetary gear set 5 is installed, power transmission and blocking between them are possible. The first clutch C1 is installed, and between the planetary carrier on which the pinion gear 13 of the double pinion planetary gear set 3 is installed and the planetary carrier 11 of the single pinion planetary gear set 5 are the power between them. A second clutch C2 is provided to enable transmission and interruption to constitute a gear train.

In addition, the sun gear 17 of the double pinion planetary gear set 3 and the sun gear 19 of the single pinion planetary gear set 5 are fixedly coupled by the power transmission member 21 so that they can always be integrally driven. It is connected.

On the other hand, the gear train configured by connecting the two planetary gear sets 3 and 5 in a variable and fixed coupling structure as described above, when the shift is realized, the ring gear 7 of the double pinion planetary gear set 3 and The ring gear 7 of the double pinion planetary gear set 3 and the transmission housing 23 stop the planet carrier 11 of the single pinion planetary gear set 5 connected by one clutch C1 so that they act as reaction elements. The first brake B1 is variably installed between the first gear B1 and the sun gear 17 of the double pinion planetary gear set 3 and the sun gear of the single pinion planetary gear set 5 connected to the power transmission member 21. 19), the second brake B2 is variably installed between the sun gear 19 and the transmission housing 23 of the single pinion planetary gear set 5 so that they act as a reaction force element.

In addition, the input shaft 1 and the double pinion planetary gear set 3 are realized by the first and second clutches C1 and 2 and the first and second brakes B1 and 2 so as to realize a shift of 5 forward speeds and 1 reverse speed. A third clutch C3 is variably installed between the planet carriers 15 of the planetary carriers 15 to allow power transmission and interruption therebetween in the forward shift stage, and the sun gear of the input shaft 1 and the double pinion planetary gear set 3 17), a fourth clutch C4 is variably provided in the reverse shift stage to enable power transmission and interruption therebetween.

Meanwhile, the transfer drive gear 27 formed integrally with the ring gear 25 of the single-pinion planetary gear set 5 is gear-coupled with a transfer driven gear (not shown) to transfer the power shifted to the differential device through the final reduction gear. In the present configuration, such a structure is omitted since a known one can be used, and any structure can be used to realize the object intended by the present invention.

The power train for the automatic transmission of the present invention made as described above comprises three elements of the two planetary gear sets 3 and 5 by means of friction elements (clutch and brake) which are selectively activated or deactivated by the transmission control unit (sun gear). , One or more elements of the planetary carrier and ring gear) are selected as the input element, and the other element is selected as the reaction force element, thereby outputting a transmission ratio of 5 forward speeds and 1 reverse speed.

The transmission control unit activates or deactivates the friction element as shown in [Table 1].

TABLE 1

Friction element operating table for each gear.

When the shift lever (not shown) is selected as the forward D range and the opening amount of the throttle valve is increased, the transmission control unit causes the gear train to output the first and third clutches C1 and 3 so that the gear train outputs the first speed ratio. Hydraulic pressure is supplied to one brake B1 to operate these friction elements.

Hereinafter, the first, second, third, and fourth clutches C1, 2, 3, and 4 and the first and second brakes B1 and 2 mean that hydraulic pressure is supplied from the hydraulic control system.

When the first and third clutches C1 and 3 and the first brake B1 are operated, the planetary carrier of the ring gear 7 and the single pinion planetary gear set 5 of the double pinion planetary gear set 3 is operated. 11 is connected.

Accordingly, since the ring gear of the double pinion planetary gear set 3 and the planet carrier 11 of the single pinion planetary gear set 5 act as reaction elements by the first brake B1, the rotational force of the input shaft 1 is reduced to zero. It is transmitted to the planet carrier 15 of the double pinion planetary gear set 3 which is an input element by the three clutch C3 and rotates it forward.

Accordingly, the rotational power transmitted to the planet carrier 15 is a single pinion planetary gear set connected to the sun gear 17 and the power transmission member 21 through the pinion gear 13 installed in the double pinion planetary gear set 3. It is transmitted to the sun gear 19 of 5) to reverse it.

The reverse rotational force transmitted to the sun gear 19 is transmitted to the ring gear 25 while forwardly rotating its ring gear 25 through the pinion gear 9 of the single-pinion planetary gear set 5. It is transmitted to the formed transfer drive gear 27 to output a speed ratio of one speed.

When the vehicle speed is increased in the first speed state, the transmission control unit deactivates the first brake B1 and operates the second brake B2 while the first and third clutches C1 and 3 are operated. .

Since the sun gear 17 of the double pinion planetary gear set 3 and the sun gear 19 of the single pinion planetary gear set 5 act as a reaction element by the above-described action, the planets of the double pinion planetary gear set 3 are operated. The rotational power transmitted to the carrier 15 is transmitted to the ring gear 7 through its pinion gear 13 to rotate it forward.

Accordingly, the rotational power transmitted to the ring gear 7 is transmitted to the planet carrier 11 of the single pinion planetary gear set 5 connected to the ring gear 7 by the first clutch C1 to rotate them forward.

Therefore, the forward rotational power transmitted to the planet carrier 11 of the single pinion planetary gear set 5 is transmitted to the ring gear 25 while forwardly rotating the ring gear 25 through the pinion gear 9 thereof. It is transmitted to the transfer drive gear 27 formed as is to output the speed ratio of the second speed.

When the vehicle speed increases in the second speed state, the transmission control unit deactivates the second brake B2 and operates the second clutch C2 while the first and third clutches C1 and 3 operate. .

The rotational force of the input shaft 1 transmitted to the planet carrier 15 of the double pinion planetary gear set 3 by the third clutch C3 while the two planetary gear sets 3 and 5 are locked by the above operation. Is transmitted to the ring gear 25 of the single-pinion planetary gear set 5 as it is (transmission ratio 1: 1) while being transmitted to the transfer drive gear 27 formed integrally therewith, thereby outputting a transmission ratio of three speeds.

When the vehicle speed increases in the third speed state, the transmission control unit deactivates the first clutch C1 and operates the second brake B2 in the state where the second and third clutches C2 and 3 operate. .

By the above-described action, since the sun gear 17 of the double pinion planetary gear set 3 and the sun gear 19 of the single pinion planetary gear set 5 act as reaction elements, the rotational power transmitted to the input shaft 1 is The third and second clutches C3 and 2 are transmitted to the planet carrier 15 of the double pinion planetary gear set 3 and the planet carrier 11 of the single pinion planetary gear set 5 to rotate them forward.

The rotational power transmitted to the planet carrier 11 of the single-pinion planetary gear set 5 is transmitted to the ring gear 25 while being increased through the pinion gear 11 thereof and integrally formed as a transfer drive gear 27. It transmits and outputs a gear ratio of 4 speeds.

In the four-speed state as described above, the sun gear 17 of the double pinion planetary gear set 3 and the single pinion planetary gear set 5 that are operated by the second brake B2 are fixed and connected by the power transmission member 21. The power loss is reduced by fixing (19) to remove the high speed rotating elements.

When the vehicle speed increases in the fourth speed state, the transmission control unit deactivates the second brake B2 and operates the first brake B1 while the second and third clutches C2 and 3 operate. .

Since the ring gear 7 of the double pinion planetary gear set 3 acts as a reaction element by the above action, the rotational power transmitted to the input shaft 1 is transmitted as in the fourth speed, and the double pinion planetary gear set is The rotational force of the pinion gear 13 of (3) is transmitted to its sun gear 17 and is transmitted to the sun gear 19 of the single pinion planetary gear set 5 connected thereto by the power transmission member 21 to reverse it.

The reverse rotational power of the sun gear 19 of the planetary gear set 5 of the single-pinion planetary gear set 5 is further transmitted to the ring gear 25 through its pinion gear 9 so that the ring gear 25 can be transferred to the ring gear 25. Further forward rotation is transmitted to the transfer drive gear 27 integrally formed in the ring gear 25 to output a speed ratio of five speeds.

In the fifth speed state as described above, the first brake B1 is operated to fix the ring gear 7 of the double pinion planetary gear set 3 to remove the high-speed rotating element, thereby reducing power loss.

On the other hand, when the reverse R range is selected by the shift lever, the transmission control unit TCU operates the first and fourth clutches C1 and 4 and the first brake B1.

Since the ring gear 7 of the double pinion planetary gear set 3 and the planet carrier 11 of the single pinion planetary gear set 5 act as a reaction element by the above-described action, the double pinion planetary gear set 3 The rotational power of the input shaft 1 transmitted to the sun gear 17 is transmitted to the sun gear 19 of the single-pinion planetary gear set 5 connected to the power transmission member 21 to rotate it forward.

Therefore, the forward rotational power transmitted to the sun gear 19 of the single-pinion planetary gear set 5 is reversed through the pinion gear 9 through the pinion gear 9 to the reaction force of the planetary carrier 11 of the planetary gear set 5. It is transmitted to the ring gear 25 while rotating, and outputs a speed ratio of reverse speed 1 through the transfer drive gear 27 formed integrally therewith.

As described above, the power train for the automatic transmission according to the present invention implements 5 forward speeds and 1 reverse speed with two planetary gear sets and six friction elements. In the forward 1 speed, the sun gear of the two planetary gear sets is used as a brake means. In the fifth forward speed, the ring gear of the double-pinion planetary gear set is fixed by the brake means, thereby miniaturizing the automatic transmission and minimizing the power loss.

Claims (4)

Double pinion planetary gear set having an input shaft that receives rotational power of the engine from the turbine of the torque converter and an element that is variably connected to the transmission housing to adjust the rotational speed of the input to the rotational power of the input shaft. A single pinion planetary gear set having an element fixedly and variably connected to an element of the double pinion planetary gear set and an element variably connected to the transmission housing and shifting and outputting according to the power transmitted from the double pinion planetary gear set. Clutch means that is variablely installed between each element of the two planetary gear set to transfer the rotational power of the input shaft to one element and more elements of the single pinion planetary gear set through the double pinion planetary gear set, One of the double pinion planetary gear sets Double pinion planetary gear sets and single to fix one element of the single pinion planetary gear set and the single pinion planetary gear set variablely connected to the saw and clutch means, and one element of the double pinion planetary gear set fixed thereto. Brake means which are variably installed between the elements of the pinion planetary gear set and the transmission housing, respectively, between the elements of the input shaft and the double pinion planetary gear set to transmit the rotational power of the input shaft to one element of the double pinion planetary gear set. A power train for an automatic transmission comprising other clutch means that are variably installed. 2. The planetary carrier of claim 1, wherein the clutch means is provided between the ring gear of the double pinion planetary gear set and the planet carrier of the single pinion planetary gear set to interlock power transmission therebetween. And a second clutch disposed therebetween to intermit power transmission between the planetary carrier of the single-pinion planetary gear set. The double gear pinion planetary gear set according to claim 1, wherein the brake means stops the planetary carrier of the double pinion planetary gear set and the planetary carrier of the single pinion planetary gear set which is variably connected via the clutch means. And a gear installed between the sun gear of the single-pinion planetary gear set and the transmission housing so that the sun gear of the first brake and double pinion planetary gear set and the sun gear of the single-pinion planetary gear set fixedly connected thereto can be stopped at the same time. Power train for automatic transmission with 2 brakes. The third clutch, the sunshaft of the input shaft and the double pinion planetary gear set according to claim 1, wherein the other clutch means is variably installed between the input shaft and the planetary carrier of the double pinion planetary gear set to enable transmission and interruption of rotational power of the input shaft. A power train for an automatic transmission comprising a fourth clutch variably installed therebetween.