JP2002295621A - Power transmitting mechanism and vehicle using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a current AT vehicle, using an epicyclic gear as a transmission that a change gear ratio is hard to be freely designed, in relation to the characteristic of a desirable vehicle because the epicyclic gear forming condition is hard, and to provide a power transmitting mechanism facilitated in design, by using an epicyclic roller transmitting mechanism. SOLUTION: The epicyclic roller transmitting mechanism 14, having a sun roller 21, an epicyclic gear 22, a ring roller 23 and a carrier 24, is used as a single structural element of a power transmitting means. The epicyclic roller transmitting mechanism 14, a clutch 15, a band brake 16 and a one-way clutch 17 are immersed with the traction oil which is used shared, and the sufficient frictional force can be generated at a small oil pressure in comparison with an AT power transmitting mechanism used in a current vehicle, and a compact power transmitting mechanism at a low cost can be thereby realized. Furthermore, loss of the oil pressure is reduced, and the transmission efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission mechanism for a vehicle and a vehicle using the same, and more particularly to a power transmission mechanism for a vehicle, which has improved design flexibility and reduced physique, and uses the same. About the vehicle that was.

[0002]

2. Description of the Related Art As a power transmission means of a vehicle, there are a stepped transmission that changes stepwise and a continuously variable transmission (C) that changes steplessly.
VT) is known. Examples of the stepped transmission include a manual transmission (MT) using a gear train and an automatic transmission (AT) using a planetary gear.
There is. About this, "Mitsuhiko Kuroda: Introduction to Automotive Engineering: Grand Prix Publishing (1990) pp. 114-124"
It is described in. The principle of automatic transmission of an AT car is described in detail in "Kenichi Sakamoto: Introduction to Automatic Transmission: Grand Prix Publishing (1995)".

On the other hand, as examples of the CVT, a belt type CVT using the principle of a friction wheel and a toroidal CVT using a traction drive are known. About this, "Car & Maintenance Magazine Vol. 54 No. 6 (200
0) pages 50 to 63 ".

Further, in recent years, hybrid vehicles having two types of power sources such as an engine and a motor and transmitting power to a final-stage reduction gear through power transmission means have appeared. This is described in, for example, JP-A-5-319110.

[0005]

In a conventional vehicle, a stepped transmission transmits torque by gears, and a continuously variable transmission transmits torque by friction. The power transmission mechanism using gears has a simple mechanism and does not require much processing accuracy, but since the speed ratio is determined by the gear ratio, the speed ratio cannot be freely designed. For example, it is impossible to create a mechanism in which the speed ratio is an irrational number. In particular, since the conditions for establishing a planetary gear are strict, this restriction is remarkable in a vehicle power transmission mechanism using a planetary gear. Further, the stepped transmission achieves a desired gear ratio by changing the connection state of gears having various gear ratios. However, the size of the connecting means cannot be ignored, and it is desired to reduce the size of the connecting means.

On the other hand, a CVT using the principle of a friction wheel has an advantage that the required gear ratio can be freely realized, but in order for the friction wheel to transmit torque, a sufficient pressing force is applied in a direction perpendicular to the friction surface. It is necessary, and the hydraulic system and mechanism system for that are complicated. Therefore, at present, there is a problem that the price of the CVT is higher than that of the stepped transmission.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to realize a power transmission mechanism which is relatively small and inexpensive and has a high degree of freedom in designing a gear ratio, and a vehicle using the same. That is.

[0008]

In order to achieve the above object, according to the present invention, there is provided a power transmission mechanism for inputting mechanical power from a heat engine and outputting mechanical power, wherein the power transmission mechanism includes a plurality of planetary drive units. The power transmission mechanism has a connection mechanism that connects the rotating shaft of the constituent rollers of the planetary drive mechanism to another rotating shaft or a casing, and the connecting mechanism is realized by a wet friction element, and the wet friction One of the friction surfaces of the element is in contact with the other friction surface via the oil of the planetary drive mechanism, and the constituent rollers of the planetary drive mechanism are constituted by a sun roller, a planetary roller, a ring roller carrier, and the planetary roller At least one of the planetary rollers circumscribes the sun roller.
One is inscribed in the ring roller, and the carrier is held so as to revolve the planetary roller around the central axis of the sun roller and to be able to rotate around the central axis of the planetary roller. A restraint means is fitted between the planetary rollers and between the planetary rollers and the ring rollers so as to generate a pressing force, and any one of the plurality of sun rollers, the plurality of ring rollers, and the plurality of carriers is restrained by the casing. And
The power transmission mechanism is used for a vehicle.

That is, by using the planetary roller mechanism, it is possible to secure a low cost and a high degree of freedom in gear shifting design. Also, by using a wet friction element as the connection mechanism and providing it in the same casing as the planetary roller mechanism, the connection mechanism can use the traction oil of the traction roller, and a higher frictional force can be generated,
The power transmission capacity per physique can be improved.

[0010]

Embodiments of the present invention will be described below.

FIGS. 1 to 3 show an example of the structure of a vehicle power transmission means according to the present invention.

FIG. 1 is an overall configuration diagram of a vehicle power transmission means according to the present invention. FIG. 2 is a configuration diagram of a planetary roller transmission mechanism serving as a planetary drive mechanism which is a feature of the present invention.
FIG. 3 is a configuration diagram showing connection means for connecting a rotating shaft to another rotating shaft or a casing to switch a gear ratio. For simplicity, bearings, holding mechanisms, and the like are omitted.

In FIG. 1, 1 is an input shaft and 2 is an output shaft. In the present embodiment, the mechanical power input from the input shaft 1 is shifted and transmitted to the output shaft 2. 11 is a torque converter, 12 is a torque converter casing, 13 is a roller casing, 14 is a planetary roller transmission mechanism, 15 is a clutch, 16 is a band brake, 17 is a one-way clutch, and 18 is an oil seal. The configuration of the planetary roller transmission mechanism 14 will be described later with reference to FIG. The clutch 15 is realized by a wet friction element such as a wet multi-plate clutch, which will be described later with reference to FIG.

In the configuration shown in FIG. 1, mechanical power output from an engine (not shown) is input from an input shaft 1 to a planetary roller transmission mechanism 14 via a torque converter 11. Here, the clutch 15, the band brake 16,
Planetary roller transmission mechanism 14 by one-way clutch 17
Is changed, and the mechanical power is transmitted to the output shaft 2 at a certain speed ratio. Clutch 15, Band brake 1
6. The operation of the one-way clutch 17 is the same as that described in the above-mentioned document "Kenichi Sakamoto: Introduction to Automatic Transmission: Grand Prix Publishing (1995)", and thus the details are omitted. Traction oil (not shown) is sealed in the roller casing 13 and functions as a power transmission medium. The oil seal 18 is provided to prevent the traction oil from leaking outside the roller casing 13.

A feature of the present invention is that the planetary roller transmission mechanism 14 is provided.
Is used as one component of the vehicle power transmission means. The planetary roller transmission mechanism 14 implements a planetary mechanism using a traction drive. The traction drive transmits mechanical power between two objects using the shear resistance of traction oil. Traction oil has the property that the shear resistance becomes very large when pressure is applied. An example using the traction drive is the toroidal CVT described above.

Hereinafter, the planetary roller transmission mechanism 1 will be described with reference to FIG.
4 will be described.

In FIG. 2, 21 is a sun roller, 22 is a planetary roller, 23 is a ring roller, and 24 is a carrier. The planetary roller transmission mechanism 14 has a plurality of planetary rollers 22. The planetary rollers 22 circumscribe the sun roller 21, and the planetary roller 22 inscribes the ring roller 23. The carrier 24 revolves the planetary rollers 22 around the central axis of the sun roller 21 and holds the planetary rollers 22 so as to be able to rotate around the central axes of the respective planetary rollers 22. The inscribed surface radius of the ring roller 23 is made smaller than the sum of the radius of the sun roller 21 and the radius of the planetary roller 22 under the same environmental conditions. A pressing force can be generated between the planetary roller 22 and the ring roller 23. The ring roller 23 can be fitted by, for example, shrink fitting or tapering.

The power transmission characteristic of the planetary roller transmission mechanism 14 is the same as that of the planetary gear mechanism, but has an advantage different from that of the planetary gear. That is, the planetary roller transmission mechanism 14 has a higher degree of freedom in designing the gear ratio than the planetary gear. Since the gear ratio of the gear is determined by the gear ratio, only a simple fraction ratio can be obtained. Further, in a commonly used involute gear, it is difficult to obtain a gear having less than a certain number of teeth due to the interference with the down-coupling, and the range of possible gear ratios is limited. In addition to these restrictions, the conditions for forming a planetary gear are even more stringent.

In the planetary roller transmission mechanism 14, assuming that the radius of the sun roller 21 is Rs, the radius of the planetary roller is Rp, and the radius of the ring roller is Rr when the mechanical system assembly is completed, the constraint condition is a center distance condition of Rr = Rs + 2Rp. Although there are constraints such as non-interference conditions in which the planetary rollers do not interfere with each other, the constraints are less strict than those of the planetary gears, and the design is much simpler.

As described above, the use of the planetary roller transmission mechanism 14 has the advantage that the degree of freedom of the transmission ratio that can be taken as a vehicle transmission is increased and the design is facilitated.

Further, since the planetary roller transmission mechanism 14 has the same mechanical power transmission characteristics as the planetary gear, it can be easily replaced with an existing AT vehicle. Since the switching sequence of the clutch 15 and the band brake 16 for performing the shift is the same as that of the existing AT vehicle, many parts can be shared.
This indicates that many of the components currently mass-produced can be diverted, and can suppress an increase in cost. Further, the manufacture of the rollers is easier than that of the gears, and the cost of the entire transmission can be reduced.

Further, since the planetary roller transmission mechanism 14 has no backlash, there is an advantage that noise is reduced.
Therefore, an energy transmission efficiency is high, and an efficient transmission can be realized.

Next, the clutch 15 will be described with reference to FIG. 31 is an oil passage, 32 is a clutch piston, 33 is a driven plate, and 34 is a drive plate. In the structure of the clutch 15, the hydraulic pressure is applied to the clutch piston 32 from the oil passage 31 as in the prior art, and the driven plate 33
And the drive plate 34 is pressed to generate a frictional force.

In the present embodiment, the clutch 15 is located in the roller casing 13 and is filled with traction oil. Therefore, the driven plate 33 and the drive plate 34 are pressed via the traction oil. As described above, traction oil has the property of increasing the shear rigidity under high pressure and increasing the frictional force.

In this embodiment, the planetary roller transmission mechanism 1
4, clutch 15, band brake 16, and one-way clutch 17 are immersed in common traction oil. Therefore, a sufficient frictional force can be generated with a small oil pressure as compared with an AT power transmission mechanism used in a conventional vehicle, and a small and inexpensive power transmission mechanism can be realized. Also,
It also has the characteristics of reducing hydraulic pressure loss and improving transmission efficiency. In particular, when the present invention is applied as an AT power transmission mechanism for a vehicle as in the present embodiment, the effects of the present invention such as small size and high efficiency as described above are remarkably exhibited because there are many friction elements.

FIG. 4 shows an example in which the planetary roller transmission mechanism 14 is used in a hybrid vehicle (HEV). Although there are various configurations of the HEV, the feature of the present invention appears in a configuration in which a plurality of power generation sources and an output shaft are coaxially connected.

FIG. 4 shows an example in which a planetary roller transmission mechanism 14 is applied as a vehicle power transmission mechanism. 41 is an engine, 42 is a motor, and 43 is a wheel. The features of FIG.
The planetary gear portion described in JP-A-5-319110 is changed to a planetary roller transmission mechanism 14. Since the rotation axis of the planetary drive mechanism is coaxial, it is preferable that the rotation axes of the plurality of power generation sources are also coaxial with the rotation axis of the planetary drive mechanism. Even when this mechanism is applied to an HEV, there is an advantage that a compact and high-efficiency transmission mechanism that can easily design a power transmission ratio can be realized.

[0028]

As described above, according to the present invention, a vehicle power transmission mechanism having a high degree of design freedom can be obtained by the planetary roller transmission mechanism. For this reason, it becomes easy to design the power transmission ratio in accordance with the desired vehicle characteristics. Further, since the hydraulic pressure loss is reduced and the transmission efficiency is improved, a compact and highly efficient vehicle power transmission mechanism and a vehicle using the same can be realized.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a vehicle power transmission unit according to the present invention.

FIG. 2 is a configuration diagram of a planetary roller transmission mechanism that is a feature of the present invention.

FIG. 3 is a configuration diagram showing connection means for connecting a rotating shaft to another rotating shaft or a casing to switch a gear ratio.

FIG. 4 is an embodiment of a hybrid vehicle according to the present invention.

[Explanation of symbols]

1: input shaft, 2: output shaft, 11: torque converter, 1
2: Torque converter casing, 13: Roller casing, 14: Planetary roller transmission mechanism, 15: Clutch, 1
6 ... Band brake, 17 ... One-way clutch, 18
... oil seal, 21 ... sun roller, 22 ... planet roller, 23 ... ring roller, 24 ... carrier, 31 ... oil passage, 32 ... clutch piston, 33 ... driven plate, 34 ... drive plate, 41 ... engine, 42 ...
Motor, 43 ... wheels.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuo Morooka 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Kiyoji Minegishi 6-chome Asahimachi, Obu City, Aichi Prefecture 1st place Sumitomo Heavy Industries Machinery Co., Ltd. Nagoya Works (72) Inventor Atsushi Tomanaga 6-1, Asahimachi, Obu City, Aichi Prefecture Sumitomo Heavy Industries Machinery Co., Ltd. Nagoya Works F-term (reference) 3J051 AA02 AA06 AA09 BA03 BB04 BB08 BC03 BD02 BE03 CA10 CB01 DA09 ED04 ED17 FA01

Claims (2)

[Claims] 1. A power transmission mechanism for inputting mechanical power by a heat engine and outputting mechanical power, wherein the power transmission mechanism has a plurality of planetary drive mechanisms, and the power transmission mechanism is a drive mechanism of the planetary drive mechanism. A connecting mechanism for connecting the rotating shaft of the constituent roller to another rotating shaft or a casing, the connecting mechanism being realized by a wet friction element, wherein one of the friction surfaces of the wet friction element is connected to the other friction surface and the planet; The planetary drive mechanism comprises a sun roller, a planetary roller, a ring roller, and a carrier, wherein at least one of the planetary rollers is circumscribed by the sun roller; At least one is inscribed in the ring roller, and the carrier revolves the planetary roller around the central axis of the sun roller and the carrier of the planetary roller The ring roller is held so as to be able to rotate around a central axis, the ring roller is fitted between the sun roller and the planetary roller and between the planetary roller and the ring roller so as to generate a pressing force, and the plurality of sun rollers A power transmission mechanism characterized in that any one of a ring roller and a plurality of carriers is provided with a restraining means restrained by the casing. 2. A vehicle using a power transmission mechanism for inputting mechanical power from a heat engine and outputting mechanical power, wherein the power transmission receives mechanical power from the heat engine and outputs mechanical power. In the mechanism, the power transmission mechanism includes a plurality of planetary drive mechanisms, the power transmission mechanism includes a connection mechanism that connects a rotation shaft of a constituent roller of the planetary drive mechanism to another rotation shaft or a casing, and the connection includes: The mechanism is realized by a wet friction element, one of the friction surfaces of the wet friction element is in contact with the other friction surface via oil of the planetary drive mechanism, and the constituent rollers of the planetary drive mechanism are sun rollers.
It is composed of planetary rollers, ring rollers and carriers,
At least one of the planetary rollers is circumscribed by the sun roller, at least one of the planetary rollers is inscribed by the ring roller, and the carrier revolves the planetary roller around a central axis of the sun roller and the planetary roller The ring roller is held so as to be able to rotate around a central axis thereof, and the ring roller is fitted so as to generate a pressing force between the sun roller and the planetary roller and between the planetary roller and the ring roller, and the plurality of sun rollers A vehicle using a power transmission mechanism, wherein any one of the ring roller and the plurality of carriers is provided with a restraining means restrained by the casing.