JP2002340121A - Toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toroidal type continuously variable transmission capable of providing stability of a speed change by making rigidity of trunnions and yokes uniform by differentiating the shapes of left and right yokes and lengthening a durability life by equalizing deformation of the yokes. SOLUTION: In this toroidal type continuously variable transmission in which the trunnions L and R provided with each of power rollers 15 are provided so as to face each other between input/output discs facing each other and coaxially arranged, shaft parts of upper parts of the trunnions L and R and shaft parts of lower parts are supported by an upper yoke 50 and a lower yoke 51, respectively, and outward load is applied to the trunnions L and R facing each other when load is inputted, shapes with respect to thickness of parts for receiving load of each trunnion L and R in each of the yokes 50 and 51 are made different on a side for receiving load of the one trunnion L of the trunnions L and R facing each other and a side for receiving load of the other trunnion R.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toroidal type continuously variable transmission used as a transmission mechanism of, for example, an automobile.

[0002]

2. Description of the Related Art Toroidal-type continuously variable transmissions have been developed and put into practical use as transmission mechanisms for automobiles and the like.

FIG. 7 shows an example of a double cavity type half toroidal type continuously variable transmission. This toroidal-type continuously variable transmission 10 includes a first cavity 11 and a second cavity 14, and these cavities 11, 1
Reference numerals 4 denote input disks 1 arranged opposite to each other.
2 and an output disk 13.

[0006] A pair of power rollers 15 are provided between the input / output disks 12 and 13, that is, in the cavities 11 and 14 so as to face each other.
5 is in contact with the traction surface of each of the disks 12 and 13.

The power rollers 15 are mounted via pivot shafts 19 on trunnions 17 provided in the cavities 11 and 14 so as to face each other, and are rotatably supported by power roller bearings 16.

[0006] The trunnion 17 is provided with the input / output disks 12 and 1.
3 and is supported so as to be capable of tilting displacement rotating about its axis and axial displacement moving in the axial direction about a pivot 18 mounted on the lower part thereof. . The traction surface of each of the discs 12 and 13 has a concave shape obtained by rotating an arc around the pivot 18 about an axis perpendicular to the pivot 18.

Each input disk 12 is mounted on the input shaft 20 so as to be movable in the axial direction thereof while being prevented from rotating by the ball splines 21 and 22 respectively.

Therefore, each input disk 12 is connected to the input shaft 2
0 and rotate together. The input shaft 20 is provided with a bearing 26 on a drive shaft 25 rotated by a drive source such as an engine.
Are rotatably connected via a.

Each output disk 13 is rotatably supported on an input shaft 20 via bearings 30 and 31.
The output disks 13 are connected by a connecting member 32 and rotate in synchronization with each other. The connection member 32 is provided with an output gear 33.

A pressing mechanism 40 is provided on the back side of the input disk 12 in the first cavity 11, and the pressing mechanism 40 includes a cam disk 41 and a roller 42. The cam disk 41 is rotatably supported on the input shaft 20 via a thrust bearing 43.
Opposite surfaces of the cam disk 41 and the input disk 12 are cam surfaces 44 and 45, respectively. A plurality of rollers 42 are sandwiched between the cam surfaces 44 and 45.

When the drive shaft 25 rotates while the rollers 42 are sandwiched between the cam surfaces 44 and 45, the cam disk 41 rotates integrally with the drive shaft 25, and the first cavity is formed via the rollers 42. The input disk 12 at 11 is pressed toward the output disk 13 side, and the input disk 12 rotates integrally with the cam disk 41.

Further, since the reaction force received by the cam disk 41 is applied to the input shaft 20 via the thrust bearing 43, the input disk 12 in the second cavity 14 is pressed toward the output disk 13.

In this way, the cam disk 41 is
, The input disks 12 rotate, and the rotational force of each input disk 12 is transmitted to the output disk 13 via the power roller 15 and output via the output gear 33.

Each trunnion 17 is, as shown in FIG.
It comprises a main portion 17a and shaft portions 17b and 17c integrally formed on the upper and lower portions of the main portion 17a. Shafts 17b, 17
c protrudes from one side of the main portion 17a and is disposed coaxially with the pivot 18.

The power roller 15 is provided between the upper shaft 17b and the lower shaft 17c of the trunnion 17,
The power roller 15 is rotatably supported by a pivot shaft 19 rotatably attached to the main portion 17a of the trunnion 17.

The upper and lower shaft portions 17b of each trunnion 17
17c are support portions 46, 4 in the casing of the transmission 10.
7 and the lower yoke 5
1 is supported. Shaft 17 of trunnion 17
Needle bearings 53 are provided at b and 17c, respectively. The needle bearings 53 include an outer ring 54 and a needle roller 55 as a rolling element interposed between the inner periphery of the outer ring 54 and the inner periphery of the shaft portions 17b and 17c. The needle bearings 53 are fitted into circular fitting holes 56 formed in the yokes 50 and 51, and the trunnions 17 are rotatably supported by the yokes 50 and 51 via the needle bearings 53. ing.

A circular fitting hole 57 is formed at an intermediate portion between the yokes 50 and 51, and the fitting hole 57 is
Is fitted on the outer periphery of the support shaft 58 attached to the shaft.

FIG. 9 shows the upper and lower yokes 50,5.
1, and upper and lower shaft portions 17b and 17c of four trunnions 17 disposed in the cavities 11 and 14, respectively.
Are supported by fitting holes 56 formed in the upper and lower yokes 50 and 51, respectively, and the upper and lower yokes 50 and 51 are connected to the four trunnions 17.
It has a role in stabilizing the gear shifting state.

Pulleys 59 are provided below the shaft portions 17c of the respective trunnions 17, and a synchronous cable 60 is provided between the pulleys 59 to synchronize and tilt the respective trunnions 17 mutually.
Is laid in a cross-shaped pattern.

A hydraulic cylinder mechanism 61 is provided on each pivot 18 of each trunnion 17, and these hydraulic cylinder mechanisms 61 are driven via one control valve (not shown).

When the gear ratio is switched, each cylinder mechanism 61 is driven by the control valve, and each trunnion 17 is displaced in the axial direction. In accordance with this displacement, the peripheral surface of each power roller 15 and the input disk 12 and output disk 13 The direction of the tangential force acting on the contact portion with the traction surface changes. Then, the trunnion 17 tilts around the axis in accordance with the change in the direction of the force, and the tilting displacement causes the circumferential surface of the power roller 15 to abut on the traction surfaces of the input disk 12 and the output disk 13. And the rotation speed ratio between the input shaft 20 and the output gear 33 changes. The displacement of one trunnion 17 is sequentially fed back to the control valve, and based on this feedback, each trunnion 1
7 is controlled to an amount corresponding to the shift command, and the gear ratio is set to the target value.

The trunnions 17 inserted into the cavities 11 and 14 are opposed to each other with a pair of them separated from each other. Here, one trunnion on the left side is L,
Assuming that the other right trunnion is R, the left trunnion L and the right trunnion R have different shapes as shown in FIG. That is, one trunnion L and the other trunnion R are pivot shaft 19
The position of the insertion port 19a for inserting the This is so that the direction of occurrence of the side slip generated on the left and right power rollers 15 at the time of load input is on the same shift side on the left and right (in the case of the figure, the speed increasing side).

When a load is input, the power roller 15 pivots about the pivot shaft 19 and shakes its head. The right and left power rollers 15 move in opposite directions (lower for the trunnion L and upper for the trunnion R) as indicated by broken lines in FIG.

Therefore, the positions of the load points received by the right and left trunnions L and R from the power roller 15 are different. Become closer to the upper side.

The four trunnions in each of the cavities 11 and 14 are supported by the yokes 50 and 51 at points S and T shown in FIG.
Since the positions of the load points received from the power rollers 15 are different, the magnitudes of the loads received by the yokes 50 and 51 naturally differ between the S point and the T point.

As shown in FIG. 12 (B), at the trunnion L, the load point is lower than the center, so that a larger load is applied to the point T than to the point S.
A large load is applied to the point. That is, the yoke 50,
The load applied to 51 is different between left and right.

[0027]

As described above, although the load applied to the yoke is different between the left and right, the yoke in the conventional toroidal type continuously variable transmission is disclosed in, for example,
As shown in 11-173393, the left and right shapes are the same.

As a result, the deformation of the yoke becomes non-uniform on the left and right, and the rigidity of the trunnion and the yoke becomes non-uniform. In addition, there is a problem that the durability life is shortened.

The present invention has been made in view of such a point. The object of the present invention is to make the shape of the yoke different on the left and right to make the rigidity of the trunnion and the yoke uniform so that the stability of gear shifting is improved. It is another object of the present invention to provide a toroidal-type continuously variable transmission which can extend the durable life by equalizing the deformation of the yoke.

[0030]

According to the present invention, in order to attain the above object, trunnions each having a power roller are opposed to each other between input and output disks arranged coaxially opposite to each other. In the toroidal type continuously variable transmission in which the upper shaft portions of these trunnions are supported by the upper yoke and the lower shaft portions are respectively supported by the lower yoke, and a load facing the outside is applied to the trunnions facing each other when a load is input, The shape of the thickness and width of the portion of each yoke that receives the load of each trunnion,
The side where the load of one trunnion opposing each other receives the load is different from the side where the load of the other trunnion receives the load.

The invention according to claim 2 is characterized in that a positioning means is provided for defining the orientation at the time of assembling each yoke in a predetermined direction.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the shape of the upper and lower yokes 50, 51 that receive the load of each trunnion L, R is changed between the portion that receives the load of one trunnion L and the other trunnion R. And the part that receives the load.

As shown in FIG. 1A, when the distance between the supporting points of the pair of trunnions L and R opposed to each other with respect to the yokes 50 and 51 is 2Y, as shown in FIG. In this case, the load point that the trunnions L and R receive from the power roller is shifted by y from the center O of the trunnions L and R. Considering the balance of moments of this time, the upper and lower yokes 50 and 51 thereof trunnion L, the load applied from the R _R A, the ratio of _{R B is, R A: R B = (} Y-y) :( Y +
y).

Therefore, in order to uniformly deform the yokes 50 and 51 that receive such a load difference, as shown in FIG. 1B, portions (yokes) of the yokes 50 and 51 that receive loads from the trunnions L and R are used. (Outer part) of the slab to change its shape with respect to its thickness and width.

First, a case where only the thickness is changed will be described.

[0036] Considering the top of the yoke 50, the upper portion of the yoke 50 joined by load _{R A} from the trunnion L, load of _{R B} is applied from the trunnion R. At this time, thicknesses h such that the maximum bending stresses of the left and right portions of the yoke 50 [the rectangular parallelepiped in FIG.

[0037]

(Equation 1)

When the lower yoke 51 is similarly considered, the lower yoke 51 has a left-right reversed relationship with the upper yoke 50.

For this reason, as a first embodiment of the present invention, as shown in FIG. 2, the upper yoke 50 has a portion that receives the load of the trunnion L (portion A indicated by oblique lines in FIG. 2). Is thinned (h ₁ ), and the thickness of the portion of the trunnion R that receives the load (portion B indicated by oblique lines in the figure) is increased (h ₂ ).

In the lower yoke 51, the portion receiving the load of the trunnion L (the portion C indicated by oblique lines in the drawing) is increased in thickness (h ₂ ), and the portion receiving the load of the trunnion R (oblique lines in the drawing). (Portion D shown by) is reduced (h ₁ ).

By making the shapes of the thicknesses of the yokes 50 and 51 right and left different in this way, the yokes 50
The load difference between the left and right of the load 51 can be absorbed. Thereby, the rigidity of the trunnions L and R and the yokes 50 and 51 becomes uniform, and the stability of the shift can be obtained. Also, since the deformation of the trunnions L and R can be made uniform, the yoke 5
The life of 0, 51, etc. can be extended.

Next, a case where only the width is changed will be described.

Left and right portions of yokes 50 and 51 [FIG. 1 (B)]
Are determined so that the maximum bending stress of the rectangular parallelepiped is equal.

[0044]

(Equation 2)

When the lower yoke 51 is similarly considered, the lower yoke 51 has a left-right reversed relationship with the upper yoke 50.

For this reason, as a second embodiment of the present invention, as shown in FIG. 3, a portion of the upper yoke 50 which receives the load of the trunnion L (portion A indicated by oblique lines in FIG. 3). Is narrowed (b ₁ ) and the trunnion R
(B ₂ ) of the portion receiving the load (part B shown by oblique lines in the figure).

The lower yoke 51 receives a load of the trunnion L (C shown by oblique lines in the figure).
Part) is widened (b ₂ ), and the part receiving the load of the trunnion R (part D shown by oblique lines in the figure) is narrowed (b ₁ ).
I do.

As described above, the shapes of the yokes 50 and 51 with respect to the width on the left and right are made different, so that the yokes 50 and 5 are formed.
1 can absorb the left and right load difference. Thereby, the rigidity of the trunnions L and R and the yokes 50 and 51 becomes uniform, and the stability of the shift can be obtained. Also, since the deformation of the trunnions L and R can be made uniform, the yoke 5
The life of 0, 51, etc. can be extended.

It is also possible to change the thickness and width, and this case will be described.

Left and right portions of yokes 50 and 51 [FIG. 1 (B)
The relationship between the thickness h and the width b is determined so that the maximum bending stress of the rectangular parallelepiped becomes equal.

[0051]

(Equation 3)

By making the shapes of the thicknesses and widths of the yokes 50 and 51 different from each other on the left and right as described above, it is possible to absorb the difference in load between the yokes 50 and 51 on the left and right.
Thereby, the rigidity of the trunnions L and R and the yokes 50 and 51 becomes uniform, and the stability of the shift can be obtained. Further, since the deformation of the trunnions L and R can be made uniform, the life of the yokes 50 and 51 can be extended.

By the way, the values of Y and y shown in FIG.
When 0 mm and y = 0.5 mm, (Y−y) :( Y + y) = 99.5: 100.5 ≒ 99: 100, and a load difference of about 1% occurs between the left and right sides of the yokes 50 and 51. Therefore, in this case, the thickness (h) of the yokes 50 and 51 is made to have a dimensional difference of about 1% between the left and right according to the equation (1), and the equation (2)
As a result, a dimension difference of about 0.5% occurs in the width (b).

As described above, by changing the shape of the yokes 50 and 51 with respect to the thickness and width on the left and right sides, the stability of the shift can be obtained and the life of the yokes 50 and 51 can be extended.

Here, if the yokes 50, 51 are mistakenly assembled in the right and left directions and the yokes 50, 51 are assembled, the stability of the gear shift is lost, and the yoke 5
The life of 0, 51, etc. is also shortened.

FIG. 4 shows a toroidal-type continuously variable transmission provided with a positioning means capable of assembling the yokes 50, 51 in a predetermined direction without confusing the right and left directions of the yokes 50, 51. Is shown.

In this toroidal type continuously variable transmission, a pin hole-shaped concave portion 50a is formed on one surface of the upper yoke 50 at a position deviated to one of the right and left sides with respect to the center thereof. A pin-shaped convex portion 46a corresponding to the concave portion 50a is formed. And the yoke 5
When the 0 concave portion 50a is fitted to the convex portion 46a of the support portion 46, the yoke 50 is oriented in a predetermined direction.

On one surface of the lower yoke 51, a pin hole-shaped concave portion is deviated to one of the left and right sides with respect to the center thereof and is point-symmetric with the concave portion 50 a of the upper yoke 50. 51a are formed, and a pin-shaped convex portion 47a corresponding to the concave portion 51a is formed on the support portion 47. When the concave portion 51a of the yoke 51 is fitted to the convex portion 47a of the support portion 47, the yoke 51 is oriented in a predetermined direction.

According to such a configuration, the yokes 50, 5
When assembling the yoke 5, unless the concave portions 50 a and 51 a and the corresponding convex portions 46 a and 47 a are fitted, the yoke 5
0, 51 interfere with the convex portions 46a, 47a, and the assembling cannot be achieved. Therefore, the concave portions 50a, 51a and the convex
The yokes 50 and 51 are assembled in a predetermined direction so that the yokes 50 and 51 are fitted with each other. This makes it possible to reliably prevent the yokes 50 and 51 from being incorrectly assembled. In this case, when the upper yoke 50 is rotated by 180 ° in the same plane, the position of the concave portion 50a coincides with the position of the concave portion 51a of the lower yoke 51. Can be used.

FIG. 5 shows another positioning means.
The size of the inner diameter of one fitting hole 57 and the other fitting hole 57 arranged in the front-rear direction of the yokes 50 and 51, and the support shaft 58 into which the one fitting hole 57 fits and the other fitting hole The size of the outer diameter of each of the support shafts 58 into which the 57 is fitted is a size corresponding to the fitting hole 57. The upper yoke 50 and the lower yoke 51 are reversed in the front-rear relationship. The corresponding fitting hole 57 and the supporting shaft 5
The yoke 50, 51 is oriented in a predetermined direction when 8 is fitted.

Even in such a case, as long as the fitting hole 57 and the support shaft 58 corresponding to each other are not fitted, the yoke 5
The yokes 50 and 51 are assembled in a predetermined direction so that the fitting holes 57 and the supporting shafts 58 are fitted to each other so that the fittings 0 and 51 interfere with the supporting shafts 58 and cannot be achieved. This makes it possible to prevent a mistake in assembling the yoke.

However, in this case, if the yokes 50, 51 are mounted upside down, the yokes 50, 51 will be upside down. Therefore, at least one of the fitting holes 5
As shown in FIG. 6, projections 57a are provided on one side of the yokes 50, 51 on the periphery of the projection 7, so that the projections 57a can prevent the yokes 50, 51 from being mounted in an inverted state. What should I do?

Also in this case, when the upper yoke 50 is rotated by 180 ° in the same plane, the positions of the fitting holes 57 having different sizes are changed to the fitting holes 57 of the lower yoke 51.
, It is possible to use the same common yoke as the upper and lower yokes 50, 51.

[0064]

As described above, according to the present invention,
The difference in load between the left and right sides of the yoke can be absorbed and its deformation can be equalized.This makes the rigidity of the trunnion and the yoke uniform and achieves the stability of gear shifting. Can be extended.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining the theory of the present invention.

FIG. 2 is an explanatory diagram for explaining the first embodiment of the present invention.

FIG. 3 is an explanatory diagram for explaining a second embodiment of the present invention.

FIG. 4 is an explanatory view showing a configuration of a positioning means for defining a direction of a yoke.

FIG. 5 is an explanatory view showing another configuration of the positioning means for defining the direction of the yoke.

FIG. 6 is an enlarged sectional view showing a part of the configuration of the positioning means.

FIG. 7 is a sectional view showing the structure of a toroidal type continuously variable transmission.

FIG. 8 is a cross-sectional view showing a structure of a trunnion arrangement portion of the toroidal-type continuously variable transmission.

FIG. 9 is a plan view showing upper and lower yokes supporting the trunnion.

FIG. 10 is a cross-sectional view for explaining a difference in the shape of a pair of trunnions.

FIG. 11 is an explanatory diagram for explaining a difference in movement of a power roller provided on the trunnion.

FIG. 12 is an explanatory diagram for explaining a difference in load applied to a yoke.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Toroidal type continuously variable transmission 11, 14 ... Cavity 12 ... Input disk 13 ... Output disk 15 ... Power roller 17 ... Trunnion (L, R) 17b, 17c ... Shaft part 19 ... Pivot shaft 56, 57 ... Fitting hole 58: Support shaft 20: Input shaft 50, 51 ... Yoke

Claims (2)

[Claims] 1. A trunnion having a power roller is provided facing each other between input and output disks coaxially facing each other. An upper shaft of the trunnions is formed by an upper yoke by a lower shaft. Parts are supported by the lower yoke, and a load directed toward the outside is applied to the trunnions facing each other when a load is input. In the toroidal-type continuously variable transmission, the shapes of portions of the yokes receiving the loads of the trunnions are opposite to each other. A toroidal-type continuously variable transmission characterized in that the side receiving the load of one trunnion is different from the side receiving the load of the other trunnion. 2. The toroidal-type continuously variable transmission according to claim 1, further comprising positioning means for defining a predetermined orientation of each yoke when assembled. transmission.