KR100199177B1 - Power train for automatic transmission of a vehicle - Google Patents

Abstract

A powertrain of an automatic transmission for a vehicle having a compound planetary gear set comprising a single pinion planetary gear set and a double pinion planetary gear set, the powertrain comprising: An input shaft that receives rotational power of the engine from the turbine of the torque converter and rotates; A single pinion planetary gear set for adjusting an output rotation speed with respect to an input according to the number of elements to which rotational power of the input shaft is transmitted; A double pinion planetary gear set which receives the output of the single pinion planetary gear set and is capable of outputting at different speed change ratios in the single pinion planetary gear set while at least one element acts as a reaction force element at each speed change stage ; Clutch means for transmitting the rotational power of the input shaft to select any one of the three elements of the single and double pinion planetary gearset or the two elements simultaneously as inputs; Another clutch means for selectively connecting any one element of the single pinion planetary gear set and any one element of the double pinion planetary gear set; And brake means operable to select one element of the double pinion planetary gear set as a reaction element when the input is selected by the clutch means or to stop the operation of the double pinion planetary gear set Thereby providing a powertrain of the automatic transmission.

Description

Automotive powertrain powertrain

FIG. 1 is a view showing a power train of a transmission according to the present invention; FIG.

FIG. 2 shows a friction element operation table for each gear range of the transmission according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission, and more particularly, to an automatic transmission that minimizes frictional loss of a friction element that does not operate in a powertrain employing a compound planetary gear set including a single pinion planetary gear set and a double pinion planetary gear set Gt; powertrain. ≪ / RTI >

BACKGROUND ART [0002] In general, a vehicular automatic transmission includes a transmission control unit that automatically controls a transmission ratio according to a running speed of a vehicle and a variation in load.

The transmission control unit controls any one of the three elements (sun gear, ring gear, and planetary carrier) of the planetary gear set as an input element by controlling a plurality of friction elements provided on the gear train to be in an operating or non-operating state, Is selected as a reaction force element to adjust the output stage revolution speed.

In order to design a gear train capable of outputting a forward speed ratio of substantially forward 4th speed and reverse 1 speed, one compound planetary gear device and at least five friction elements must be used.

Of these friction elements, the turning radius of the friction element used as the clutch means has a structural constraint that the clutch means must be smaller than the turning radius of the output element to be connected to the input shaft and smaller than the turning radius of the reaction force element.

Generally, a compound planetary gear device has a direct-coupled structure in which at least two different elements can be used in common with each other.

Since a compound planetary gear unit has four independent speeds in the case of a 4-speed automatic transmission, a compound planetary gear unit using two simple planetary gear units having three independent speeds can not achieve six independent speeds Because.

2. Description of the Related Art [0002] Generally, a compound planetary gear device used as an automatic transmission of a vehicle includes a rabbit type, a quadruple type, and a two simple type planetary gear device.

Such a compound planetary gear device may have a structure in which the planetary carriers are connected to each other so as to be used as a transmission means of a vehicle or may have a structure in which the planetary carrier and the ring gear are directly connected with each other, As shown in FIG.

Therefore, at any gear stage, the clutch means or brake means which does not substantially affect the shifting causes friction between the driving side and the driven side, resulting in power loss.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art as described above, and it is an object of the present invention to provide a clutch hook up which has not been proposed so far so as to minimize frictional loss of a non- The powertrain of the vehicle automatic transmission.

Specifically, the clutch hook-up provided by the present embodiment directly connects the sun gear of the single pinion planetary gear set to the planetary carrier of the double pinion planetary gear set, and the planetary carrier of the single pinion planetary gear set and the planetary carrier of the double pinion planetary gear set The ring gear is connected in a variable manner, and the most important purpose is to provide a power train that minimizes the frictional loss of the friction element at the fourth forward gear position.

In order to achieve the object of the present invention as described above, there is provided a torque converter comprising an input shaft that receives rotation power of an engine from a turbine of a torque converter,

A single pinion planetary gearset set for adjusting an output rotation speed with respect to an input according to a number of elements to which rotational power of the input shaft is transmitted;

A double pinion planetary gear set that receives the output of the single pinion planetary gear set and that at least one element acts as a reaction force element at each speed change stage so that output can be made at different speed change ratios in the single pinion planetary gear set Wow;

Clutch means for transmitting the rotational power of the input shaft to select any one of the three elements of the single and double pinion planetary gearset or the two elements simultaneously as inputs;

A clutch mechanism selectively connecting one of the elements of the single pinion planetary gear set to one of the elements of the double pinion planetary gear set;

And brake means operable to select one element of the double pinion planetary gear set as a reaction element when the input is selected by the clutch means or to stop the operation of the double pinion planetary gear set Thereby providing a powertrain of the automatic transmission.

Wherein the clutch means comprise first clutch means for transmitting power between the input shaft and the sun gear of the single pinion planetary gear set;

Second clutch means for selectively transmitting power between the planetary carrier of the single pinion planetary gear set and the ring gear of the double pinion planetary gear set;

And a third clutch that selectively transmits power between the input shaft and the planetary carrier of the single pinion planetary gear set. The powertrain of the vehicle automatic transmission includes:

The brake means comprise first brake means for selecting the sun gear as a reaction force element between the sun gear of the double pinion planetary gear set and the transmission housing;

And a second brake means for selecting the ring gear as a reaction force element between the ring gear of the double pinion planetary gear set and the transmission housing.

The planetary carrier of the sun gear and double pinion planetary gear set of the single pinion planetary gear set described above provides a powertrain of a vehicular automatic transmission having a fixed engagement structure by a power transmitting member.

The planetary carrier of the single pinion planetary gear set and the ring gear of the double pinion planetary gear set described above provide the powertrain of the vehicular automatic transmission having the variable engagement structure by the clutch means.

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

1 is a view showing a powertrain of an automatic transmission according to the present invention and has a structure in which the rotational power of an engine E can be torque-converted by a torque converter T and transmitted to an input shaft 2 of a transmission portion.

In the present embodiment, the input shaft 2 transmits torque from the turbine of the torque converter T to the single pinion planetary gear set 4. The single pinion planetary gear set 4 includes a double pinion planetary gear set 4, The torque is transmitted to the set 6 and the clutch hook-up is performed in which the ring gear 8 and the transfer drive gear 10 are integrally formed.

The sun gear 12 of the single pinion planetary gear set 4 and the planetary carrier 14 of the double pinion planetary gear set 6 are directly connected to each other through the power transmitting member 16, do.

The sun gear 12 of the single pinion planetary gear set 4 is configured to receive the rotational power through the first clutch means 18 provided between the sun gear 12 and the input shaft 2.

The planetary carrier 20 of the single pinion planetary gear set 4 is rotated integrally with the ring gear 22 of the double pinion planetary gearset 6 by the second clutch means 24, As shown in Fig.

The single pinion planetary gear set 4 described above is provided with the third clutch means 26 between the input shaft 2 and the planetary carrier 20 so that two elements can be selected as inputs to be rotated integrally.

The first, second and third clutch means described above may be used with a generally used multi-disc clutch.

Braking means are provided in order to enable the planetary gear set to regulate the number of rotations of the output to the input when one or more of the clutch means are in operation.

The first brake means 28 is provided between the transmission housing 30 and the sun gear 32 of the double pinion planetary gear set 6 so as to select the sun gear 32 as a reaction element .

The second brake means 34 is provided between the transmission housing 32 and the ring gear 22 of the double pinion planetary gear set 6 so that the ring gear can be selected as a reaction force element.

1, the structure in which the transfer drive gear 10 of the power train is engaged with a transfer driven gear (not shown) and transmits the power to the differential gear through the final reduction gear is omitted. And even if a structure having any structure is used, the object of the present invention can be realized, and a description thereof will be omitted.

The powertrain of the automatic transmission according to the present invention having the above structure is configured such that the friction clutches (brake means and brake means), which are selected by the transmission control unit (not shown) (Forward gear, planetary carrier, ring gear) as the input and the other element as the reaction force element, and outputs the following forward gear 4 speed and reverse 1 speed gear ratio.

An operation table relating to the friction elements for which operation and deactivation are selected by the transmission control unit is shown in FIG.

When the selector lever (not shown) is selected as the forward (D) range and the amount of opening of the throttle valve starts to increase, the transmission control unit controls the hydraulic pressure control system (not shown) The first clutch means 18 first supplies the hydraulic pressure to operate the clutch means.

Hereinafter, the clutch means or the brake means means that the hydraulic pressure is supplied from the hydraulic control system.

When the first clutch means 18 is operated, the rotational power of the input shaft 2 is transmitted to the sun gear 12 of the single pinion planetary gear set 4, and the sun gear 12 and the power transmitting member 16 of the sun gear 12, To the planetary carrier 14 of the double pinion planetary gear set 6 via the planetary gear set 6.

The planetary carrier 20 of the single pinion planetary gear set 4 and the ring gear 22 of the double pinion planetary gear set 6 are engaged because the second clutch means 24 operates. Since the brake means 28 is operating, the sun gear 32 of the double pinion planetary gear set 6 acts as a reaction force element.

The ring gear 8 of the single pinion planetary gear set 4 rotates in the same direction as the input shaft 2 and outputs the largest reduction ratio that can be provided by the gear train of the present embodiment, .

When the vehicle speed is increased in this first speed control state, the transmission control unit newly activates the third clutch means 26 while interrupting the operation of the first clutch means 18 that selected the reaction force element.

The power is transmitted from the planetary carrier 20 of the single pinion planetary gear set 4 to the ring gear 22 of the double pinion planetary gear set 6 to be input and the double pinion planetary gear set The sun gear 32 of the sun gear 6 acts as a reaction force element.

With this operation, the ring gear 8 of the single pinion planetary gear set 4 rotates faster than the first speed and outputs the second speed ratio.

When the vehicle speed is increased in this second speed control state, the transmission control unit newly activates the first clutch means 18 while releasing the second clutch means 24, so that the input is transmitted to the single pinion planetary gear set 4, The sun gear 12 and the planet carrier 20 of the single pinion planetary gear set 4 are simultaneously rotated together.

With the above action, the ring gear 8 outputs a speed change ratio of the third speed rotating at the same rotational speed as that of the input shaft 2.

When the vehicle speed further increases in the three-speed control state in which the number of rotations of the input and the output is the same, the transmission control unit interrupts the operation of the first clutch means 18 and activates the second brake means 34 newly .

The operation of the sun gear 32 and the ring gear 22 of the double pinion planetary gear set 6 is stopped by this action to stop the overall operation of the double pinion planetary gear set 6, An input is made through the planetary carrier 20 of the single pinion planetary gear set 4 in a state where the sun gear 12 of the single pinion planetary gear set 4 connected to the pinion gear 14 acts as a reaction force element.

Therefore, the ring gear 8 of the single pinion planetary gear set 4 outputs the gear ratio of the fourth speed rotating at a speed higher than the speed of the input shaft 2.

The second clutch means 24 is not operated in the fourth speed change process as described above so that the double pinion planetary gear set 6 can be operated even if the input is made to the planetary carrier 20 of the single pinion planetary gear set 4, The power is not transmitted to the ring gear 22 of the ring gear.

When the selector lever is selected as the reverse range, the transmission control unit activates the first and second clutch means 18 and 24 to select the input element and operate the second brake means 34 to set the reaction element .

Therefore, the rotational power of the input shaft 2 is input to the sun gear 12, and the carrier 20 acts as a reaction force element, and the ring gear 8 as the output element rotates in the opposite direction to the input shaft 2, .

As described above, the powertrain according to the present invention can provide four forward shift stages and one reverse shift stage. In particular, by stopping the operation of the double pinion planetary gear set at the 4th-speed gear stage, The slip of the element can be reduced and the friction loss due to the slip of the friction element can be minimized.

Claims (1)

An input shaft that receives rotational power of the engine from the turbine of the torque converter and rotates; A single pinion planetary gear set in which the sun gear and the planetary carrier are variably connected through the input shaft and the first and third clutch means, and the ring gear acts as an output element; Wherein the sun gear and the planetary carrier of the single pinion planetary gear set are fixedly connected through a power transmitting member, the planetary carrier and the ring gear of the single pinion planetary gear set are variably connected through the second clutch means, A double pinion planetary gear set for combining the ring gear so as to selectively act as a fixed element through the first and second brake means; Powertrain of an automotive automatic transmission including.