JP2015145682A - Power-split continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power-split continuously variable transmission capable of increasing a transmission gear ratio width while avoiding expansion of the placement space of a constant transmission mechanism, and also simplifying the structure of a mode switching mechanism.SOLUTION: A power-split continuously variable transmission comprises: a continuously variable transmission mechanism 10 capable of continuously changing the speed of input rotation; a constant transmission mechanism 13 changing the speed of the input rotation at a predetermined transmission gear ratio and transmitting the resultant input rotation to an output side of the continuously variable transmission mechanism 10; and a synthesizing planetary gear mechanism 15 synthesizing the output rotation of the continuously variable transmission mechanism 10 with the rotation transmitted from the constant transmission mechanism 13, the constant transmission mechanism 13 including a transmission-gear-change planetary gear mechanism 14 provided on an input side of the continuously variable transmission mechanism 10, accelerating or decelerating the input rotation, and transmitting the resultant input rotation to the synthesizing planetary gear mechanism 15, and the transmission-gear-change planetary gear mechanism 14 including a wet brake 14d fixing a ring gear 14f.

Description

  The present invention relates to a continuously variable transmission mechanism, a constant transmission mechanism, and a power split type continuously variable transmission apparatus including a planetary gear mechanism for synthesis that combines outputs of both transmission mechanisms.

  As a conventional power split type continuously variable transmission, a continuously variable transmission mechanism (for example, a belt-type continuously variable transmission mechanism) that allows the input rotation from the engine to be continuously variable, and the input rotation is shifted at a predetermined gear ratio. Some of them have a constant speed change mechanism (for example, a gear mechanism) that transmits to the output side of the continuously variable speed change mechanism, and a synthesizing planetary gear mechanism that combines and outputs the rotations from both mechanisms. In this type of continuously variable transmission, a continuously variable transmission mode in which the input rotation from the engine is transmitted only to the continuously variable transmission mechanism, and a power split mode in which the transmission is divided and transmitted to the continuously variable transmission mechanism and the constant transmission mechanism. The switching is performed as appropriate according to the driving state of the vehicle (see, for example, Patent Document 1).

In the continuously variable transmission mode in the power split type continuously variable transmission, the speed is changed at a normal belt ratio (lowest speed ratio to highest speed ratio). When the belt ratio is the highest gear ratio or the lowest gear ratio, the power split mode is established by selectively operating the fastening element and the fixed element. In this power split mode, when the belt ratio is changed from the highest gear ratio to the lowest gear ratio, or from the lowest gear ratio to the highest gear ratio, the planetary gear mechanism makes a difference, so that the ring gear rotates at an increased or reduced speed. Therefore, the total transmission ratio width is expanded as compared with the case of only belt driving.

Japanese Patent No. 4552376

By the way, in the conventional power split type continuously variable transmission, in order to increase the total speed ratio range, the speed ratio of the constant speed change mechanism is set to the highest speed ratio or the lowest speed ratio of the belt type continuously variable speed change mechanism. And the speed must be greatly increased or decreased, and it is difficult to secure the arrangement space. As a result, there is a problem that the apparatus becomes larger.

In addition, when a wet clutch is used as the mode switching mechanism, a clutch drum, a centrifugal hydraulic canceller, and a clutch hydraulic oil seal member are required, and it is necessary to form an oil passage in the rotating shaft, resulting in a complicated structure. There's a problem.

The present invention has been made in view of the above-described conventional situation, and can increase the gear ratio width while avoiding the enlargement of the arrangement space of the constant transmission mechanism and the enlargement of the device, and the structure of the mode switching mechanism can be simplified. It is an object to provide a power split type continuously variable transmission.

The invention according to claim 1 is a continuously variable transmission mechanism capable of continuously changing the input rotation, a constant transmission mechanism that shifts the input rotation at a predetermined transmission ratio and transmits it to the output side of the continuously variable transmission mechanism, and the continuously variable transmission. A planetary gear mechanism for synthesis that combines the output rotation of the transmission mechanism and the rotation transmitted by the constant transmission mechanism; a continuously variable transmission mode in which the input rotation is transmitted only to the continuously variable transmission mechanism; and the constant transmission In a power split continuously variable transmission that can be switched to a power split mode that is split and transmitted to both the mechanism and the continuously variable transmission mechanism,
The constant speed change mechanism is provided on the input side of the continuously variable speed change mechanism, and has a speed change planetary gear mechanism that increases or decreases an input rotation and transmits the rotation to the synthesis planetary gear mechanism.
The planetary gear mechanism for speed change has a wet brake for fixing a ring gear or a sun gear.

The invention of claim 2 is the power split type continuously variable transmission according to claim 1,
The planetary gear mechanism for speed change is characterized in that the input rotation is input to a carrier and the ring gear is fixed by the wet brake to increase the speed from the sun gear and output.

According to a third aspect of the present invention, in the power split type continuously variable transmission according to the first aspect,
The planetary gear mechanism for speed change is characterized in that the input rotation is input to a carrier and the sun gear is fixed by the wet brake to increase the speed from a ring gear for output.

In the first aspect of the invention, since the constant speed change mechanism has a structure having a planetary gear mechanism for speed change, the input rotation can be increased or decreased and transmitted to the output side of the continuously variable speed change mechanism. Thus, the transmission ratio width of the entire apparatus can be increased while avoiding an increase in the size of the apparatus and, consequently, an increase in the size of the apparatus.

Also, the power split mode can be achieved by fixing the ring gear or sun gear with the wet brake of the continuously variable transmission mechanism for shifting, and the clutch drum, centrifugal hydraulic canceller, hydraulic oil for mode switching with the conventional wet clutch The oil passage configuration in the seal member and the rotating shaft can be eliminated, and the structure can be simplified.

In the invention of claim 2, the input rotation can be input to the carrier and the ring gear can be fixed to increase the output from the sun gear, and in the invention of claim 3, the input rotation can be output to the carrier. By inputting and fixing the sun gear, it is possible to output from the ring gear at an increased speed, and the gear ratio width of the entire device can be increased.

1 is a configuration diagram of a power split continuously variable transmission according to Embodiment 1 of the present invention. FIG. FIG. 3 is a velocity diagram of a planetary gear mechanism for shifting of the continuously variable transmission according to the first embodiment. FIG. 3 is a velocity diagram of a synthesis planetary gear mechanism of the continuously variable transmission according to the first embodiment. FIG. 3 is a cross-sectional development view of the continuously variable transmission according to the first embodiment. It is a block diagram of the power division type continuously variable transmission which concerns on Example 2 of this invention. It is a speed diagram of the planetary gear mechanism for shifting of the continuously variable transmission according to the second embodiment. FIG. 6 is a cross-sectional development view of a shifting planetary gear mechanism portion of the continuously variable transmission according to the second embodiment. It is a block diagram of the transmission-like planetary gear mechanism part of the continuously variable transmission which concerns on Example 3 of this invention. It is a speed diagram of the planetary gear mechanism for shifting according to the third embodiment. It is a velocity diagram of the planetary gear mechanism for synthesis according to the third embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1-4 is a figure for demonstrating the continuously variable transmission which concerns on Example 1 of this invention.

In the figure, reference numeral 1 denotes a power split type continuously variable transmission for an automobile. The continuously variable transmission 1 is a belt type in which engine rotation is input via a torque converter 2 and the input rotation is continuously and continuously variable. A continuously variable transmission mechanism 10, a constant transmission mechanism 13 that shifts the input rotation at a predetermined transmission ratio and transmits it to the output side of the belt-type continuously variable transmission mechanism 10, and an output rotation of the belt-type continuously variable transmission mechanism 10. A synthesizing planetary gear mechanism 15 for synthesizing the transmission rotation of the constant speed change mechanism 13;

An engine crankshaft 2e is connected to the drive plate 2a of the torque converter 2, and an input shaft 5 is connected to the turbine runner 2b. A forward drive unit 9 is disposed on the input shaft 5. The forward drive unit 9 includes a forward drive gear 9a rotatably mounted on the input shaft 5 and a forward clutch 9b that couples or releases the forward drive gear 9a to or from the input shaft 5. Yes.

An idler shaft 8 is disposed in parallel with the input shaft 5. An idler gear 8a that meshes with a reverse input gear 5a fixed to the distal end portion 5 'of the input shaft 5 is fixed to the base end portion 8' of the idler shaft 8, and the distal end portion 8 of the idler shaft 8 is fixed. A reverse drive unit 12 is disposed at ″.

The reverse drive unit 12 is connected to a reverse drive gear 12a rotatably attached to the idler shaft 8, and the reverse drive gear 12a is coupled to the idler shaft 8 so as to be able to transmit a rotational force, or is released to be relatively rotatable. And a reverse clutch 12b.

The belt type continuously variable transmission mechanism 10 includes a drive pulley shaft 6 disposed in parallel with the input shaft 5 and a driven pulley shaft 7 having a left portion 7 'and a right portion 7' '. The output gear 7b of the driven pulley shaft 7 meshes with the input gear 16a of the differential mechanism 16.

The drive pulley shaft 6 has a forward input gear 6a meshed with a forward drive gear 9a of the input shaft 5 fixed to an input-side base end portion 6 ', and a drive pulley 19 attached to an output-side distal end portion 6 ″. Is attached, and a reverse driven gear 6 c is fixed to the opposite side of the drive pulley 19. The reverse drive gear 12a meshes with the reverse drive gear 6c.

A driven pulley 20 is attached to the driven pulley shaft 7, and the driven pulley 20 is connected to the driving pulley 19 through a metal belt 11.

Here, the drive pulley 19 is movable in the axial direction relative to the pulley shaft 6 on the input side of the drive pulley shaft 6 and a fixed pulley half 19a integrally formed on the opposite side of the drive pulley shaft 6. The movable pulley half 19b is mounted so as to be capable of transmitting rotational force, and an oil chamber 19c is formed on the back side of the movable pulley half 19b, that is, on the forward clutch unit 9 side. By supplying hydraulic pressure to the oil chamber 19c, the movable pulley half 19b moves forward, and the effective pulley diameter of the drive pulley 19 increases and changes to the high speed side.

The driven pulley 20 includes a fixed pulley half 20a formed integrally with the driven pulley shaft 7 and a movable pulley half 20b mounted so as to be movable in the axial direction and transmit rotational force. And an oil chamber 20c formed on the back side of the movable pulley half 20b. By supplying hydraulic pressure to the oil chamber 20c, the movable pulley half 20b moves forward, and the effective pulley diameter of the driven pulley 20 increases and changes to the low speed side.

Further, the synthetic planetary gear mechanism 15 has a sun gear 15a fixed to the left portion 7 'of the driven pulley shaft 7 and is rotatable on a carrier 15b supported relative to the right portion 7' 'of the driven pulley shaft 7. The pinion gear 15c supported by the pinion gear 15c is engaged with the sun gear 15a, and the ring gear 15d engaged with the pinion gear 15c is fixed to the right portion 7 '' of the pulley shaft 7. The ring gear 15d is connected to or released from the left portion 7 'of the driven pulley shaft 7 by a clutch 15f.

A driven sprocket 15e is formed on the carrier 15b, and the driven sprocket 15e is connected to a drive gear 14b of the constant speed change mechanism 13 by a chain 17.

The constant speed change mechanism 13 includes a speed change planetary gear mechanism 14 disposed on the input side of the drive pulley shaft 6 from the drive pulley 19. The planetary gear mechanism 14 for shifting has a sun gear 14a rotatably supported by the drive pulley shaft 6, and a pinion gear 14c rotatably supported by a carrier 14e fixed to the drive pulley shaft 6. The pinion gear 14c is supported by the sun gear 14a. The ring gear 14f is meshed with the pinion gear 14c so as to be relatively rotatable.

The ring gear 14f is fixed to the transmission case by a wet brake 14d, or is rotatably released. The drive gear 14b is formed on the sun gear 14a.

In the first embodiment, the continuously variable transmission mode or the power split mode is selected and controlled according to the engine speed, vehicle speed, and the like. During forward travel in the continuously variable transmission mode, the forward clutch 9b is turned on, the reverse clutch 12b is turned off, the brake 14d is turned off, and the clutch 15f is turned on. As a result, the engine is rotated from the input shaft 5 to the forward drive gear 9a and forward. Is transmitted only to the drive pulley shaft 6 via the input gear 6a, and is shifted by the belt-type continuously variable transmission mechanism 10, and is differentially transmitted from the left portion 7 'of the driven pulley shaft 7 via the clutch 15f and the right portion 7 ". It is transmitted from the mechanism 16 to the drive wheel.

  On the other hand, during reverse travel, the forward clutch 9b is turned off, the reverse clutch 12b is turned on, the brake 14d is turned off, and the clutch 15f is turned on. As a result, the engine rotation is reversed from the input shaft 5 to the idler shaft 8, and the reverse drive gear. 12a, transmitted to the drive pulley shaft 6 via the reverse driven gear 6c, and transmitted to the drive wheels via the belt-type continuously variable transmission mechanism 10, the driven pulley shaft 7, the clutch 15f, and the differential mechanism 16.

  In the power split mode, the input rotation from the torque converter 2 is divided and transmitted to the belt type continuously variable transmission mechanism 10 and the constant transmission mechanism 13. Specifically, the brake 14d is turned on and the clutch 15f is turned off, and the input rotation is accelerated by the shifting planetary gear mechanism 14 and transmitted to the synthesizing planetary gear mechanism 15 via the chain 17, where the belt type It is combined with the output rotation from the continuously variable transmission mechanism 10 and output to the differential mechanism 16.

Specifically, in the planetary gear mechanism 14 for shifting, the ring gear 14f is fixed by a brake 14d, and the input rotation is input to the carrier 14e, and is accelerated and output from the sun gear 14a (see FIG. 2).

In this case, the speed increasing ratio of the speed changing planetary gear mechanism 14 is the same as the speed ratio of the belt type continuously variable transmission mechanism 10, and as shown in FIG. Is switched to the power split mode when is the highest gear ratio. As the belt-type continuously variable transmission mechanism 10 is shifted to the lowest gear ratio from this state, the output rotational speed of the ring gear 15d of the composing planetary gear mechanism 15 increases, and the gear ratio width increases accordingly.

As described above, in the first embodiment, the constant speed change mechanism 13 has the structure including the speed change planetary gear mechanism 14. Therefore, the input rotation can be accelerated and transmitted to the synthesizing planetary gear mechanism 15. Compared to a conventional device in which the speed change mechanism is constituted by a gear mechanism, the gear ratio width of the entire device can be increased to the highest speed ratio side while reducing the arrangement space.

More specifically, as described above, when the gear ratio of the belt-type continuously variable transmission mechanism 10 is the highest gear ratio, the power split mode is switched to, and in this state, the belt-type continuously variable transmission mechanism 10 is switched to the lowest speed. As the gear shifts to the specific side, the rotational speed of the ring gear 15d increases, and the gear ratio becomes high accordingly, and when the belt-type continuously variable transmission mechanism 10 is at the lowest gear ratio, the highest gear ratio is achieved as a unit.

Further, the power split mode can be set by fixing the ring gear 14f with the wet brake 14d of the planetary gear mechanism 14 for speed change, and the clutch drum, centrifugal hydraulic canceller, hydraulic oil for mode switching with the conventional wet clutch can be made. The oil passage configuration in the seal member and the rotating shaft can be eliminated, and the structure can be simplified.

Further, the required transmission torque capacity of the wet brake 14d can be reduced, the number of friction members can be reduced accordingly, the cost can be reduced, and the transmission efficiency can be improved.

  5-7 is a figure for demonstrating the power division type continuously variable transmission which concerns on Example 2 of this invention, and the same code | symbol as FIGS. 1-4 in the figure shows the same or equivalent part.

In the planetary gear mechanism 14 ′ for shifting in the second embodiment, the sun gear 14a is rotatably supported by the drive pulley shaft 6, and the pinion gear 14c rotatably supported by the carrier 14e fixed to the drive pulley shaft 6 is the sun gear. The ring gear 14f is engaged with the pinion gear 14c so as to be relatively rotatable, and a drive gear 14b is formed on the ring gear 14f. The sun gear 14a is fixed to the transmission case by a wet brake 14d or is released to be rotatable.

In the power split mode in the second embodiment, the input rotation from the torque converter 2 is divided and transmitted to the belt-type continuously variable transmission mechanism 10 and the constant transmission mechanism 13, and is accelerated by the planetary gear mechanism 14 'for transmission. Then, it is transmitted to the planetary gear mechanism 15 for synthesis via the chain 17. In the shifting planetary gear mechanism 14 ', the sun gear 14a is fixed by the brake 14d, and the input rotation is input to the carrier 14e and accelerated from the ring gear 14f (see FIG. 6).

  Also in the second embodiment, the same effect as the first embodiment can be obtained. In the case of the second embodiment, as shown in the figure, the drive gear 14b is formed on the outer peripheral portion of the ring gear 14f. In this case, the shaft length of the planetary gear mechanism 14 'for shifting can be shortened. Can be configured compactly.

  8 to 10 are diagrams for explaining a third embodiment of the present invention, in which the same reference numerals as those in FIGS. 1 and 2 indicate the same or corresponding parts.

In the shifting planetary gear mechanism 14 ″ in the third embodiment, the sun gear 14a is fixed to the drive pulley shaft 6, the carrier 14e is rotatably supported on the drive pulley shaft 6, and is rotatably supported on the carrier 14e. The pinion gear 14c meshes with the sun gear 14a, and the ring gear 14f meshing with the pinion gear 14c is fixed to the transmission case by a wet brake 14d or is rotatably released. A driving gear 14b is formed on the carrier 14e.

In the power split mode in the third embodiment, the input rotation from the torque converter 2 is divided and transmitted to the belt type continuously variable transmission mechanism 10 and the constant transmission mechanism 13 and decelerated by the planetary gear mechanism 14 ″ for transmission. And output to the synthesizing planetary gear mechanism 15 via the chain 17. That is, in the planetary gear mechanism for speed change 14 ″, the ring gear 14f is fixed by the brake 14d, and the input rotation is input to the sun gear 14a and is decelerated and output from the carrier 14e (see FIG. 9).

In the third embodiment, as shown in FIG. 10, when the speed ratio of the belt type continuously variable transmission mechanism 10 is the lowest speed ratio, the mode is switched to the power split mode. As the gear shifts to the high gear ratio side, the rotational speed of the ring gear 15d decreases, and the gear ratio becomes low accordingly, and when the belt-type continuously variable transmission mechanism 10 is at the highest gear ratio, the unit becomes the lowest gear ratio.

  Thus, in the third embodiment, the speed ratio width of the entire apparatus can be increased to the lowest speed ratio side while avoiding an increase in the arrangement space.

DESCRIPTION OF SYMBOLS 1 Power split type continuously variable transmission 10 Belt type continuously variable transmission mechanism (continuously variable transmission mechanism)
13 Constant transmission mechanism 14 Planetary gear mechanism for transmission 14a Sun gear 14d Wet brake 14f Ring gear 15 Planetary gear mechanism for synthesis

Claims (3)

A continuously variable transmission mechanism capable of continuously changing the input rotation, a constant transmission mechanism that shifts the input rotation at a predetermined transmission ratio and transmits the same to the output side of the continuously variable transmission mechanism, and an output rotation of the continuously variable transmission mechanism that is constant. A planetary gear mechanism for synthesis that combines the rotation transmitted by the speed change mechanism;
Power split capable of switching between a continuously variable transmission mode in which input rotation is transmitted only to the continuously variable transmission mechanism and a power split mode in which the input rotation is divided and transmitted to both the constant transmission mechanism and the continuously variable transmission mechanism In a continuously variable transmission,
The constant speed change mechanism is provided on the input side of the continuously variable speed change mechanism, and has a speed change planetary gear mechanism that increases or decreases an input rotation and transmits the rotation to the synthesis planetary gear mechanism.
The transmission planetary gear mechanism has a wet brake for fixing a ring gear or a sun gear, and is a power split type continuously variable transmission. The power split type continuously variable transmission according to claim 1,
The speed-change planetary gear mechanism is a power split type continuously variable transmission, wherein the input rotation is input to a carrier and the ring gear is fixed by the wet brake to increase the speed from the sun gear. The power split type continuously variable transmission according to claim 1,
The transmission planetary gear mechanism is a power-dividing continuously variable transmission, wherein the input rotation is input to a carrier and the sun gear is fixed by the wet brake to increase the speed from a ring gear.

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