KR100279408B1 - Power train for automatic transmission - Google Patents

Abstract

In order to reduce the number of planetary gear sets and at the same time achieve the 5th forward and the 1st reverse speed by using a small number of friction elements, and to miniaturize the automatic transmission; In forming a power train of an automatic transmission for a vehicle that can obtain a shift stage of forward 1 speed and reverse 1 speed by combining first and second double pinion planetary gear sets on the same axis as the input shaft that receives rotational power from the engine, A first double pinion planetary gear set in which a planet carrier and a sun gear are variably connected to an input shaft via a clutch means, and a second double pinion planetary gear set in which a planet carrier acts as an output element, the first double pinion planet Ring gear of the second double pinion planetary gear set is fixedly connected to the sun gear of the gear set and the sun gear of the second double pinion planetary gear set, and the planetary carrier and the ring gear of the first double pinion planetary gear set are interposed by clutch means. And a ring gear of the first double pinion planetary gear set and a second double pinion planetary By a brake means interposed respectively the sun gear of the set in connection with the transmission housing to provide a power train for an automatic transmission made.

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 the three elements of the planetary gear set (ie, 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 planetary gear set constituting the sub transmission, and operates the planetary gear sets. 6,7 friction elements are used.

Therefore, such a powertrain for automatic transmissions uses a lot of planetary gear sets, which causes a lot of frictional elements, thereby causing 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 set 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.

And 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 ring gear of another double pinion planetary gearset, respectively, and fixedly connect the sun gears of the 2 double pinion planetary gear set, 4 forward It is to provide a power train for an automatic transmission that minimizes power loss while miniaturizing the automatic transmission by preventing rotation of the planetary gear set of the second planetary gear set at a higher speed than the input shaft or the output shaft at the fifth speed.

In order to realize this, the power train for the automatic transmission according to the present invention combines the first and second double pinion planetary gear sets on the same axis as the rotating input shaft by receiving rotational power from the engine, and thus the gear stages of the forward 1 speed and the reverse 1 speed. In forming a power train of a vehicular automatic transmission that can be obtained, a first double pinion planetary gear set in which a planetary carrier and a sun gear are variably connected to an input shaft via a clutch means, and a second double in which the planetary carrier acts as an output element. Combining the pinion planetary gear set, but fixedly connecting the sun gear of the first double pinion planetary gear set and the sun gear of the second double pinion planetary gear set, clutching the planet carrier and the ring gear of the first double pinion planetary gear set Variably connected to the ring gear of the second double pinion planetary gear set via the means, and Provided is a power train for an automatic transmission, in which a ring gear of a first double pinion planetary gear set and a sun gear of a second double pinion planetary gear set are respectively connected to a transmission housing via brake means.

The power train for the automatic transmission configured as described above operates 5 speeds and 1 reverse speed by operating or deactivating the clutch means and the brake means, and at the forward speeds 4 and 5, the rotary element of the double-pinion planetary gear set is input shaft or Prevents rotation at higher speeds than the output shaft.

Hereinafter, the preferred configuration and operation of the present invention will be described in more 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.

FIG. 1 is a first configuration diagram of a power train for an automatic transmission according to the present invention, in which a rotational power of the engine E is torque converted from a torque converter T to be transmitted to an input shaft 1 of a gear train. consist of.

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

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

The sun gear 15 of the first double pinion planetary gear set 3 and the sun gear 17 of the second double pinion planetary gear set 5 are always fixed by the power transmission member 19 so that they can be integrally driven. It is connected by a coupling structure.

On the other hand, the gear train configured by connecting two planetary gear sets 3 and 5 in a variable and fixed coupling structure as described above, when the gear shift is realized, the ring gear 7 of the first double pinion planetary gear set 3. And the ring gear 9 of the second double pinion planetary gear set 5 connected to the first clutch C1 to stop the ring gear 9 so that they act as reaction elements (the ring gear of the first double pinion planetary gear set 3). 7) a second brake B1 is variably installed between the transmission housing 21 and a second gear connected to the sun gear 15 of the first double pinion planetary gear set 3 and the power transmission member 19 thereto. A second brake (B2) between the sun gear 17 of the second double pinion planetary gear set 5 and the transmission housing 21 such that the sun gear 17 of the double pinion planetary gear set 5 is stopped so that they act as reaction elements. ) Is configured to install variable.

In addition, the input shaft 1 and the first double pinion planetary gear set are realized by the first and second clutches C1 and 2 and the first and second brakes B1 and B2 to realize the shifting of the 5th forward and the 1st reverse speed. A third clutch C3 is variably provided between the planetary carriers 13 in the forward shift stage to enable power transmission and interruption therebetween, and the input shaft 1 and the first double pinion planetary gear set 3 are provided. A fourth clutch C4 is variably provided between the sun gears 15 of the crank wheels 15 to enable power transmission and blocking between them at the reverse gear stage.

Meanwhile, the transfer drive gear 27 formed integrally with the planetary carrier 25 in which the pinion gear 23 of the second double pinion planetary gear set 5 is installed is geared with a transfer driven gear (not shown) for final deceleration. The transmission of the shifted power to the differential through the gears is omitted in this configuration because such a structure can be known and any structure can be used to achieve the intended purpose of the present invention.

The power train for the automatic transmission of the present invention made as described above is composed of two planetary gear sets (3,5) and three elements (sun gears) by friction elements (clutch and brake), which are selectively activated or deactivated by the transmission control unit. , 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].

If 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 may allow the gear train to output the first and third clutches C1 and 3 so as to output a gear ratio of one speed. 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 ring gear 7 and the second double pinion planetary gear set 5 of the first double pinion planetary gear set 3 are operated. ) Ring gear 9 is connected.

Therefore, since the ring gears 7 and 9 of the two planetary gear sets 3 and 5 act as reaction elements by the first brake B1, the rotational power of the input shaft 1 is input by the third clutch C3. It is transmitted to the planet carrier 13 of the double pinion planetary gear set 3 as an element to rotate it forward.

Accordingly, the rotational power transmitted to the planet carrier 13 is transmitted through the pinion gear 11 installed in the first double pinion planetary gear set 3 to the sun gear 15 and the second double pinion connected to the power transmission member 19. It is transmitted to the sun gear 17 of the planetary gear set 5 to reverse it.

In addition, the reverse rotational power transmitted to the sun gear 17 is transmitted to the planet carrier 25 while rotating the planet carrier 25 forward through the pinion gear 23 of the second double pinion planetary gear set 5. It is transmitted to the transfer drive gear 27 formed integrally to output a speed ratio of one speed.

When the vehicle speed increases 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 gears 15 and 17 of both double pinion planetary gear sets 3 and 5 act as reaction elements by the above-described action, they are transmitted to the planet carrier 13 of the first double pinion planetary gear set 3. Rotational power is transmitted to the ring gear 7 via its pinion gear 11 to rotate it forward.

Accordingly, the rotational power transmitted to the ring gear 7 is transmitted to the ring gear 9 of the second double pinion planetary gear set 5 connected to the ring gear 7 by the first clutch C1 to rotate them forward. Let's do it.

Therefore, the forward rotational power transmitted to the ring gear 9 of the second double pinion planetary gear set 5 is transmitted to the planet carrier 25 while rotating the planet carrier 25 forward through its pinion gear 23. It is transmitted to the transfer drive gear 27 formed integrally with this 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 input shaft 1 transmitted to the planet carrier 13 of the first double pinion planetary gear set 3 by the third clutch C3 while the two double pinion planetary gear sets 3 and 5 are locked by the above operation. Rotational power of) is transmitted to the planetary carrier 25 of the second double pinion planetary gear set 5 (shift ratio 1: 1) while being transmitted to the transfer drive gear 27 formed integrally therewith to output a three-speed transmission ratio. do.

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 while the second and third clutches C2 and 3 operate. .

Since the sun gears 15 and 17 of both double pinion planetary gear sets 3 and 5 act as reaction elements by the above-described action, the rotational power transmitted to the input shaft 1 is the third and second clutches C3 and 2. ) Is transmitted to the planet carrier 13 of the first double pinion planetary gear set 3 and the ring gear 9 of the second double pinion planetary gear set 5 to rotate them forward.

The rotational power transmitted to the ring gear 9 of the second double pinion planetary gear set 5 is transmitted to the planet carrier 25 while being increased through the pinion gear 23 thereof and integrally formed therewith. ) Is transmitted to output the gear ratio of 4 speed.

In the fourth speed state as described above, the second brake B2 is operated to fix the sun gears 15 and 17 of the double pinion planetary gear sets 3 and 5 fixedly connected by the power transmission member 21 to rotate at high speed. Eliminating the elements reduces power loss.

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 first 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. The rotational force of the pinion gear 11 of the double pinion planetary gear set 3 is transmitted to the sun gear 15 thereof and to the sun gear 17 of the second double pinion planetary gear set 5 connected thereto by the power transmission member 19. Delivered to reverse it.

The reverse rotational power of the sun gear 17 of the second double pinion planetary gear set 5 is further transmitted to the planet carrier 25 through its pinion gear 23 so as to rotate the planet carrier 25 further forward. It is transmitted to the transfer drive gear 27 formed integrally to output a speed ratio of five speeds.

In the fifth speed state as described above, the first brake B1 operates to fix the ring gear 7 of the first 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 gears 7 and 9 of both double pinion planetary gear sets 3 and 5 act as reaction elements by the above-described action, the input shaft transmitted to the sun gear 15 of the first double pinion planetary gear set 3 is transmitted. The rotational power of (1) is transmitted to the sun gear 17 of the second double pinion planetary gear set 5 connected to the power transmission member 19 to rotate it forward.

Therefore, the forward rotational power transmitted to the sun gear 17 of the second double pinion planetary gear set 5 is transmitted to the planet carrier 25 through the pinion gear 23 by the reaction force of the ring gear 9 of the planetary gear set 5. While the reverse rotation is transmitted to the ring gear 25 is transmitted to the transmission speed of the reverse 1 speed 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 five forward speeds and one reverse speed with two planetary gear sets and six friction elements, and in the forward four speeds, both double pinion planetary gear sets are used as brake means. The sun gears are fixed, and at the 5th forward speed, the ring gear of the first double pinion planetary gear set is fixed by the brake means, thereby miniaturizing the automatic transmission and minimizing power loss.

Claims (1)

In forming a power train of an automatic transmission for a vehicle that can obtain a shift stage of 4 forward speed and 1 reverse speed by combining the first and second double pinion planetary gear sets on the same axis as the rotating input shaft received from the engine. A first double pinion planetary gear set in which a planet carrier and a sun gear are variably connected to an input shaft via a clutch means, and a second double pinion planetary gear set in which a planet carrier acts as an output element, the first double pinion planet Ring gear of the second double pinion planetary gear set is fixedly connected to the sun gear of the gear set and the sun gear of the second double pinion planetary gear set, and the planetary carrier and the ring gear of the first double pinion planetary gear set are interposed by clutch means. And a ring gear of the first double pinion planetary gear set and a second double pinion planetary To the sun gear of each set via the brake means of the power train for an automatic transmission, characterized by yirueojim in connection with the transmission housing.