JPH0425648A - Planetary gear transmission - Google Patents

Abstract

PURPOSE:To make it compact in size and lighter in weight by setting up a first planetary gear train made up of a first sun gear element, a carrier element and a ring gear element and a second planetary gear train made up of a second sun gear element, the carrier element and the ring gear element on the same axis in parallel. CONSTITUTION:Both first and second planetary gear trains G1, G2 are set up on the same axis in parallel, and each of them is made up of first and second sun gears S1, S2, first and second pinions P1, P2 engaging these sun gears and revolving as rotating around the sun gears, first and second carrier C holding these pinions free of rotation and revolving at the same speed as these pinions P1, P2 centering on each axis of the sun gears S1, S2, and first and second ring gears R1, R2 with internal gears in mesh with the pinions P1, P2 and rotatable with each axis of the sun gears S1, S2 as the center. Engaging control over first-third clutches K1-K3 and first-third brakes B1-B3 is performed, through which the setting of shift speeds and shift control should be done.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a planetary gear transmission configured using a plurality of sets of planetary gear trains.

(Prior Art) Planetary gear transmissions are widely used as automatic transmissions for automobiles. Many conventional planetary gear transmissions are constructed by combining two sets of planetary gears, such as Ravigneau gear train and Simpson gear train, and in this case, the gears can be up to 4 forward speeds. were common. However, there is a demand for multi-speed gears for the purpose of improving driving characteristics, etc., and for this reason, transmissions having five or more forward speeds have been proposed and some have been put into practical use.

Examples of such multi-stage transmissions include JP-A-1-105043, JP-A-1-312267, JP-A-61-103654, JP-A-61-104854, and JP-A-1048.
There is a transmission disclosed in Publication No. 55 and the like. These transmissions use a Simpson gear train, which combines two planetary gear trains with three clutches and brakes each to form a transmission with five (or six) forward speeds and one reverse speed. There is. In the case of a transmission having such a configuration, only two sets of planetary gear trains are required as in the conventional transmission, and there is an advantage that parts can be shared with conventional transmissions.

(Problem to be solved by the invention) However, in order to increase the number of speed stages in this way,
It is necessary to add a clutch, brake, etc. to a conventional transmission, which tends to complicate the structure of the transmission and cause the transmission to become larger and heavier. Efforts have been made to simplify the structure of the transmission and make it smaller and lighter.

For this reason, the present invention is capable of setting five forward speeds using two sets of planetary gear trains, has a different configuration from the above-mentioned conventional proposal, and has a simplified transmission configuration and is smaller and lighter. It is an object of the present invention to provide a planetary gear transmission that can achieve the following.

Structure of the Invention Below, the structure of the present invention will be explained along with its operation based on embodiments.

As shown in FIG. 1, the planetary gear transmission of the present invention has a first
and second planetary gear trains Gl and G2 are arranged coaxially and in parallel. Double inverted star gear train G1. G2 are first and second sun gears 81 and 82, and first and second pinions Pi and P that mesh with and rotate around the first and second sun gears S1 and G2, respectively.
2, and the first and second pinions PL, P2 are rotatably held, and the first and second pinions P1. The first and second carriers C1 and C2 that revolve at the same rotation speed as P2, and the first
and first and second ring gears R1 and R2 that have internal teeth that mesh with second pinions pt and p2 and are rotatable around the axes of first and second sun gears Sl and 82.

The first sun gear Sl is detachably connected to the transmission input shaft 3 via the first clutch Kl, and a first brake B1 capable of holding the first sun gear S1 fixed is attached to the first sun gear S1.

The first carrier C1 is directly connected to the second sun gear S2, and the first carrier C1 and the second sun gear S2 are directly connected to each other.
is detachably connected to the transmission input shaft 3 via the second clutch 2, and a second brake B2 is attached to the first carrier C1 and the second sun gear S2, which can hold them fixedly. There is.

A first ring gear R1 and a second ring gear R2 are directly connected, and both of these directly connected ring gears R1°R2 are removably connected to a transmission input shaft 3 via a third clutch 3. Furthermore, a third brake B3 that can fix these ring gears R1 and R2 is attached to both ring gears R1 and R2.

The second carrier C2 is directly connected to the transmission output gear 5.

The transmission input shaft 3 is connected to an engine output shaft l via a torque converter 2. The torque converter 2 includes a pump 2a, a stator≦b, and a turbine 2c. The pump 2a is connected to the engine output shaft 1, and the turbine 2c is connected to the transmission shaft 3.

On the other hand, the transmission output gear 5 meshes with the first counter gear 6, and the output rotation of the transmission output gear 5 is directly transmitted to the first counter gear 6. This e output rotation is transmitted to the second counter gear 8 via the counter shaft 7, transmitted to the differential mechanism 10 via the final gear 9 meshing with the second counter gear 8, and from the differential mechanism 10 to the left and right axle shafts. It is divided into 11 and 12 parts and transmitted.

In the planetary gear transmission configured as described above, the first to
1 to 3 to the third clutch and the first to third brakes B1
By performing the engagement/disengagement control of ~B3, it is possible to set the gear stage and perform speed change control. Specifically, as shown in the table in Fig. 2, if engagement/disengagement control is performed, 5th forward speed (LOW
, I.S.T.

2ND, 3RD, 4TH and 5TH), reverse 1st speed (
REV) can be set. In addition, in the table of Figure 2,
O indicates that the clutch and brake are engaged.

As you can see from this table, 5 forward speeds (LOW to 57H)
) is set by engaging two of the clutch and brake (these are referred to as retaining means). Also, when shifting between adjacent gear ranges other than between 1st and 2nd gears, one of these two locking means is released and the other locking means is engaged. The speed change control is simple during these speed changes.

On the other hand, a speed diagram showing the speed relationship of each element in the transmission with the above configuration is shown in FIG. 3, and based on this,
The reduction ratio in each speed range will be explained.

In the speed diagram of FIG. 3, the speed diagram of the first planetary gear train G1, which is composed of the first sun gear S1, the first carrier C1, and the first ring gear R1, and the speed diagram of the first planetary gear train G1, which is composed of the first sun gear S1, the first carrier C1, and the first ring gear R1, and the speed diagram of the Each speed diagram is shown separately from the speed diagram of the second planetary gear train G2 composed of two ring gears R2. In this diagram, each vertical line indicates its component, and the length of the vertical line corresponds to the number of rotations. The distance between each vertical line is proportional to the reciprocal of the number of strokes of the sun gear and the reciprocal of the number of teeth of the ring gear.

In the case of the speed diagram of the first planetary gear train G1 located at the upper side in the figure, the three vertical lines indicate the first sun gear 81. Corresponding to the first carrier c1 and the first ring gear R1, the upward length of each vertical line indicates the rotation speed n in the forward direction. Further, the interval “al” between the vertical line indicating the first sun gear S1 and the vertical line indicating the first carrier c1 is
The interval "bl" between the vertical line indicating the first carrier C1 and the vertical line indicating the first ring gear R1 corresponds to the reciprocal number ("1/Zss) of the number of teeth Zs1 of the first ring gear R1, which corresponds to the number of teeth Zr of the first ring gear R1. Corresponds to the reciprocal of □ (= 1 / Z r s ).For this reason, the first sun gear s1 is rotated at the rotation speed n,
When the first ring gear R1 is fixedly held by the second brake B2, a line connecting the points indicating both states and the first carrier C1
The rotational speed na at the intersection with the vertical line indicating the first carrier C1
The number of rotations will be.

On the other hand, the same applies to the speed diagram of the second planetary gear train G2 located at the bottom, and the three vertical lines correspond to the second sun gear S2, second carrier C2, and second ring gear R2 in order from the left. do. Therefore, the interval "a2" between the vertical line indicating the second sun gear S2 and the vertical line indicating the second carrier C2 corresponds to the reciprocal number (= 1 / Z S2) of the number of teeth ZS2 of the second sun gear S2, and The interval “b2” between the vertical line indicating the second carrier C2 and the vertical line indicating the second ring gear R2 is the distance “b2” between the vertical line indicating the second ring gear R2.
It corresponds to the reciprocal number (=1/Zr2) of the number of teeth Zrz of 2. Therefore, when the second sun gear S2 is held fixed by the second brake B2 and the second ring gear R2 is rotated at the rotation speed n, a line D' connecting the points indicating both states and a vertical line indicating the second carrier C2 are formed. The rotation speed nb at the intersection point is the rotation speed of the second carrier R2, that is, the transmission output gear 5.

Although FIG. 3 shows the planetary gear trains divided into two, the first carrier CI and the second sun gear S2 are directly connected, and the first ring gear R1 and the second ring gear R2 are connected directly to each other.
Since they are directly connected, the creation planetary gear train G1. The velocity diagram of G2 can be expressed as a combination, as shown in FIG. Therefore, the gear ratio at each speed stage is determined by plotting based on the diagram in FIG.

First, in the case of the LOW range, the first and third brakes B3 are engaged with the first clutch. As a result, the first sun gear S1 is rotationally driven at the same rotational speed nO as the transmission input shaft 3, and the first and second ring gears R1 and R2 are held fixed. Therefore, the rotation speed n1 at the intersection of the dotted straight line L1 connecting the point representing the state of the first sun gear S1 and the point representing the state of the first and second ring gears R1 and R2 and the vertical line representing the second carrier C2. is the rotation speed of the second carrier C2, and is the rotation speed of the transmission output gear 5 directly connected thereto. Then, the ratio of input and output rotation speeds at this time (= no
/nt) becomes the reduction ratio.

In the case of the second speed range, the first and third brakes B3 are disengaged from the first clutch, and instead, the third clutch and the second brake B2 are engaged. As a result, the first carrier C1 and the second sun gear S2 are held fixed, and the first and second ring gears R1 and R2 are rotationally driven at the same rotation speed n0 as the transmission input shaft 3. In this case, the rotation speed n2 at the intersection of the dotted straight line L2 and the vertical line indicating the second carrier C2 becomes the rotation speed of the transmission output gear 5.

In the case of the third speed range, the third clutch 3 remains engaged, the second brake B2 is released, and the first brake B1 is engaged instead. As a result, while the first sun gear S1 is held fixed, the first and second ring gears R1,
R2 has the same rotation speed n as the transmission input shaft 3. Rotationally driven. Therefore, the rotational speed n at the intersection of the dotted straight line L3 and the vertical line indicating the second carrier C2 becomes the rotational speed of the transmission output gear 5.

In the case of the 4th speed range, the first brake B1 is released while the third clutch 3 remains engaged, and the second clutch 2 is engaged instead. For this reason, the two-way star gear train G1.
The entire G2 rotates together with the transmission input shaft 3. On the diagram, the first carrier CL second sun gear S2f and the first and second ring gears R1 and R2 both rotate at the same time as the transmission input shaft 3, and a horizontal straight line L4 and a vertical line indicating the second carrier C2 The rotation speed n4 (=no) at the intersection of is the rotation speed of the transmission output gear 5.

In the case of the 5th speed range, the second clutch 2 remains engaged, the third clutch 3 is released, and the first brake B1 is engaged instead. As a result, the first carrier C1 and the second sun gear S2 are rotationally driven at the same rotational speed n0 as the transmission input shaft 3 while the first sun gear S1 is held fixed. Therefore, the rotational speed na at the intersection of the dotted straight line L5 and the vertical line indicating the second carrier C2 becomes the rotational speed of the transmission output gear 5.

In the case of reverse range, the first and second brakes B2 are engaged with the first clutch. Therefore, the first sun gear S1 is driven at the same rotation as the transmission input shaft 3, and the first carrier C1 and the second sun gear S2 are fixedly held. In this case, the rotation speed nR (a negative value and the rotation opposite to the input rotation) at the intersection of the dotted straight line LR and the vertical line indicating the first ring gear R1 and the second carrier C2 is the transmission output. This is the rotation speed of gear 5.

The rotation of the transmission output gear 5 shifted as described above is transmitted to the final gear 9 via the first counter gear 6, counter shaft 7 and second counter gear 8, as shown in FIG. The power is transmitted from the differential mechanism 10 to the left and right front wheels (not shown) via the left and right axle shafts 11 and 12. In addition, FIG. 1 shows the transmission arrangement of the FF horizontal type, and in this case, the transmission output gear 5
Since the is located near the center of the transmission, the counter shaft 7 that connects the differential mechanism 10 and the transmission output gear 5, which are disposed on the sides of the center of the transmission, can be made relatively short. The entire aircraft can be made smaller and lighter. It is also possible to use the transmission output gear 5 as a parking gear.

As described in detail, the present invention is comprised of two sets of planetary gear trains, three sets of clutches, and three sets of brakes arranged on the same axis, and is novel and unprecedented. It is possible to obtain a transmission which has a relatively small and compact configuration and can set a shift range of 5 forward speeds and 1 reverse speed. In addition,
When the transmission of the present invention is installed horizontally in an automobile, the output gear is located near the center of the transmission, so the axial length of the counter shaft that transmits power from the output gear to the differential gear may be short, and the transmission can be made compact.

[Brief explanation of the drawing]

FIG. 1 is a skeleton diagram showing the configuration of a planetary gear transmission according to the present invention, FIG. 2 is a surface diagram showing the relationship between clutch and brake operation and shift range in this planetary gear transmission, and FIGS. FIG. 4 is a speed diagram showing the rotational relationship of each element in the planetary gear transmission. 2... Torque converter 3... Transmission input shaft 7.
...Counter shaft 9...Final gear 10-
・Differential mechanism

Claims (1)

[Claims] 1) A first planetary gear train composed of a first sun gear element, a first carrier element, and a first ring gear element, and a second planetary gear train composed of a second sun gear element, a second carrier element, and a second ring gear element. are arranged coaxially and in parallel, the first sun gear element is removably connected to the input member via a first clutch, and a first brake capable of fixing and holding the first sun gear element is provided; Said first
A carrier element and the second sun gear element are directly coupled, and the directly coupled first carrier element and second sun gear element are detachably coupled to the input member via a second clutch, and the first carrier element and a second brake capable of fixing and holding a second sun gear element, directly connecting the first ring gear element and the second ring gear element, and engaging and disengaging both of the directly connected ring gear elements via a third clutch. while being freely connected to the input member;
A planetary gear transmission characterized in that a third brake capable of fixedly holding both ring gear elements is provided, and the second carrier element is directly connected to an output member.