JP2000199552A - Half toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a half toroidal type continuously variable transmission to secure excellent durability, perform transmission of a high power, and have excellent transmission efficiency. SOLUTION: Provided a cavity diameter is D, a half apex angle is θ0, and the curvatures of radius of the sectional shapes of the inside surfaces 2a and 4a of a disc 2 on the input side and a disc 4 on the output side are r0, a formula of k0=(D/2r0)-1 is established. Further, provided the spin angular speed of a contact oblong present at a contact part between the inside surfaces 2a and 4a of the discs 2 and 4 and the peripheral surfaces 8a and 8a of power rollers 8 and 8 is ωsp, the rotational angular speed of the disc 2 on the input side is ω1. All of k0>=0.5, θ0>=58 deg., and |ωsp/ω1|<=0.25 are satisfied. Further, traction oil is stored in a casing. The traction oil has a traction factor of 0.06 or more at an oil temperature of 100 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The half-toroidal type continuously variable transmission according to the present invention is used, for example, as a transmission unit constituting a transmission for an automobile or as a transmission for various industrial machines.

[0002]

2. Description of the Related Art The use of a half-toroidal type continuously variable transmission as schematically shown in FIGS. 1 and 2 has been studied as a transmission unit constituting a transmission for an automobile. This half toroidal type continuously variable transmission is disclosed, for example, in Japanese Utility Model Laid-Open No. 62-7146.
As disclosed in Japanese Patent Application Publication No. 5 (1994), an input disk 2 is supported concentrically with an input shaft 1, and an output disk 4 is fixed to an end of an output shaft 3 arranged concentrically with the input shaft 1. . Inside the casing containing the half-toroidal-type continuously variable transmission, trunnions 6, 6 swinging about pivots 5, 5 which are twisted with respect to the input shaft 1 and the output shaft 3, are provided.
Is provided.

That is, these trunnions 6, 6 arranged at portions off the central axis of the two disks 2, 4 have the pivots 5, 5 on the outer surfaces of both ends, respectively, and the center of the two disks 2, 4 They are provided in a direction perpendicular to the direction of the axis and concentric with each other. In addition, the trunnions 6 and 6 support the base ends of the displacement shafts 7 and 7 at the intermediate portions thereof, and swing the trunnions 6 and 6 about the pivots 5 and 5 so that the respective displacements can be adjusted. The inclination angles of the shafts 7, 7 can be adjusted freely. Power rollers 8 are rotatably supported around the displacement shafts 7 supported by the trunnions 6 respectively. The power rollers 8, 8 are sandwiched between the inner surfaces 2a, 4a of the input and output disks 2, 4 facing each other. Each of the inner side surfaces 2a, 4a has a concave section obtained by rotating an arc around the pivot 5 as described above. Then, the peripheral surfaces 8a, 8a of the power rollers 8, 8, which are formed into spherical convex surfaces, are connected to the inner surfaces 2a, 4a.
a.

A loading cam device 9 is provided between the input shaft 1 and the input disk 2, and the loading cam device 9 elastically presses the input disk 2 toward the output disk 4. The input side disk 2 is freely rotatable. The loading cam device 9 includes a loading cam 1 that rotates with the input shaft 1.
0 and a plurality (for example, four) of rollers 12, which are rotatably held by a retainer 11. One side of the loading cam 10 (right side in FIGS. 1 and 2)
A cam surface 13 which is uneven in the circumferential direction,
A cam surface 14 having a similar shape is also formed on the outer side surface (the left side surface in FIGS. 1 and 2) of the input side disk 2. Then, the plurality of rollers 12 are connected to the input shaft 1.
Are rotatably supported about a radial axis.

When the loading cam 10 rotates with the rotation of the input shaft 1 when using the half toroidal type continuously variable transmission having the above-described configuration, the cam surface 13 causes the plurality of rollers 12, 12 to move to the input side. It is pressed against a cam surface 14 formed on the outer surface of the disk 2. As a result, the input side disk 2
Is pressed by the plurality of power rollers 8, 8 and simultaneously, the two cam surfaces 13, 14 and the plurality of rollers 12, 1,
2 on the input side disk 2
Rotates. Then, the rotation of the input side disk 2 is
The output shaft 3 is transmitted to the output side disk 4 via the plurality of power rollers 8, 8 and is fixed to the output side disk 4.
Rotates.

When the rotational speed ratio (speed change ratio) between the input shaft 1 and the output shaft 3 is changed, and when deceleration is first performed between the input shaft 1 and the output shaft 3, each of the pivots 5 The trunnions 6, 6 are swung in a predetermined direction as a center. The peripheral surfaces 8a, 8a of the power rollers 8, 8 are shown in FIG.
As shown in FIG. 5, the displacement shafts 7, 7 are inclined so as to abut against the central portion of the inner surface 2a of the input disk 2 and the outer peripheral portion of the inner surface 4a of the output disk 4, respectively. Conversely, when increasing the speed,
, Each of the trunnions 6 is swung in the opposite direction. The peripheral surface 8 of each of the power rollers 8
As shown in FIG. 2, each of the displacement shafts 7a and 8a comes into contact with a portion of the inner surface 2a of the input disk 2 near the outer periphery and a portion of the inner surface 4a of the output disk 4 near the center. , 7 are tilted. If the inclination angle of each of the displacement shafts 7, 7 is set between those of FIGS. 1 and 2, an intermediate speed ratio can be obtained between the input shaft 1 and the output shaft 3.

FIGS. 3 and 4 show Japanese Utility Model Application No. 63-69293.
1 shows an example of a more specific half toroidal type continuously variable transmission described in the microfilm of Japanese Utility Model Application Laid-Open No. 1-173552. The input-side disc 2 and the output-side disc 4, which are arranged in the casing 35 with the inner side surfaces 2a and 4a facing each other, are provided with needle bearings 16 and 16 around a circular input shaft 15 respectively. It is rotatably supported via That is, in the center of the input side disk 2 and the output side disk 4, through holes 17, 17 each having a circular cross-sectional shape are formed in the axial direction (FIG. 3). Left and right directions)
Is formed so as to penetrate through. Each of the above needle bearings 1
Reference numerals 6 and 16 are provided between the inner peripheral surfaces of the through holes 17 and 17 and the outer peripheral surface of the intermediate portion of the input shaft 15. Also, retaining rings 19, 19 are locked in locking grooves 18, 18 formed in the inner peripheral surface of the end portions of the through holes 17, 17 near the inner side surface, and the needle bearings 16, 16 are fixed to the respective through holes. Hole 17, 17
From the inner surfaces 2a and 4a of the disks 2 and 4 are prevented. The loading cam 10 is spline-engaged with the outer peripheral surface of the input shaft 15 at the end (the left end in FIG. 3), and is prevented from moving away from the input side disk 2 by the outward flange-shaped flange 20. ing. Then, the loading cam 10 and the roller 12,
12 constitutes a loading cam device 9 for rotating the input side disk 2 while pressing the input side disk 2 toward the output side disk 4 based on the rotation of the input shaft 15. The output side disk 4 is provided with an output gear 21 and a key 2
The output side disk 4 and the output gear 21 rotate in synchronization with each other.

Both ends of the pair of trunnions 6, 6 are supported on a pair of support plates 23, 23 so as to be swingable and displaceable in the axial direction (front and back directions in FIG. 3, and left and right directions in FIG. 4). I have.
The displacement shafts 7, 7 are supported in circular holes 24, 24 formed in the middle portions of the trunnions 6, 6, respectively. Each of these displacement shafts 7 has a support shaft 25, 25 and a pivot shaft 26, 26 which are parallel and eccentric to each other. Each of the support shaft portions 25, 25 is connected to each of the circular holes 2 described above.
It is rotatably supported inside 4 and 24 via radial needle bearings 27 and 27. The power rollers 8, 8 are rotatably supported around the pivot shafts 26, 26 via other radial needle bearings 28, 28, respectively.

The pair of displacement shafts 7, 7 are provided at positions opposite to the input shaft 15 by 180 degrees. or,
The direction in which the respective pivot shafts 26, 26 of the respective displacement shafts 7, 7 are eccentric with respect to the respective support shafts 25, 25 is the same as the rotation direction of the input side and output side disks 2, 4. 4 (reverse direction in FIG. 4). The eccentric direction is a direction substantially orthogonal to the direction in which the input shaft 15 is provided. Accordingly, the power rollers 8 are supported to be slightly displaceable in the direction in which the input shaft 15 is provided.
As a result, due to the elastic deformation of these constituent members based on a large load applied to the constituent members in the transmission state of the rotational force, each of the power rollers 8, 8 is moved in the axial direction of the input shaft 15 (see FIG. 3). Even in the case of displacement in the left-right direction (the front-back direction in FIG. 4), this displacement can be absorbed without applying an unreasonable force to each of the above components.

Further, between the outer surface of each of the power rollers 8, 8 and the inner surface of the intermediate portion of each of the trunnions 6, 6, a thrust ball bearing 29, 29 and thrust needle bearings 30, 30 are provided. Of these, the thrust ball bearings 29, 29 allow rotation of the power rollers 8, 8 while supporting the load in the thrust direction applied to the power rollers 8, 8. Also, each of the above thrust needle bearings 3
0, 30 support the thrust loads applied from the power rollers 8, 8 to the outer races 31, 31 constituting the respective thrust ball bearings 29, 29 while supporting the pivot shaft portions 26, 2,
6 and the outer races 31, 31 are supported by the support shafts 25, 25.
Swinging around the center.

Further, drive rods 32, 32 are connected to one end (the left end in FIG. 4) of each of the trunnions 6, 6, and drive pistons 33, 32 are attached to the outer peripheral surfaces of the intermediate portions of these drive rods 32, 32. 33 is fixed. Each of the drive pistons 33 is fitted in the drive cylinders 34 in an oil-tight manner.

In the case of the half toroidal type continuously variable transmission configured as described above, the rotation of the input shaft 15 is transmitted to the input side disk 2 via the loading cam device 9. And
The rotation of the input disk 2 is transmitted to the output disk 4 via the pair of power rollers 8, 8, and the rotation of the output disk 4 is extracted from the output gear 21. When changing the rotation speed ratio between the input shaft 15 and the output gear 21, the pair of drive pistons 33 are displaced in opposite directions. Each of these drive pistons 33,
The pair of trunnions 6, 6 are displaced in opposite directions with the displacement of 33, for example, the lower power roller 8 in FIG. 4 is on the right side in FIG. 4, and the upper power roller 8 in FIG. Displaced to the left of the figure. As a result, the direction of the tangential force acting on the contact portions between the peripheral surfaces 8a, 8a of the power rollers 8, 8 and the inner surfaces 2a, 4a of the input disk 2 and the output disk 4 changes. I do. Then, with the change in the direction of the force, each of the trunnions 6,
6 swing in opposite directions about the pivots 5, 5 pivotally supported by the support plates 23, 23. As a result, as shown in FIGS. 1 and 2 described above, the contact position between the peripheral surfaces 8a, 8a of the power rollers 8, 8 and the inner surfaces 2a, 4a changes, and the input shaft 15 The rotation speed ratio with the output gear 21 changes.

Incidentally, the input shaft 15 and the output gear 2
When transmitting the rotational force between the power rollers 8, the power rollers 8, 8 are displaced in the axial direction of the input shaft 15 based on the elastic deformation of the constituent members. Each of the displacement shafts 7 that pivotally support 8 rotates slightly about each of the support shaft portions 25. As a result of this rotation, the outer ring 3 of each of the thrust ball bearings 29, 29
The outer surfaces of the trunnions 6 and 6 are relatively displaced from each other. Since the thrust needle bearings 30, 30 exist between the outer surface and the inner surface, the force required for the relative displacement is small. Therefore, the force for changing the inclination angle of each of the displacement shafts 7 can be small as described above.

The transmission efficiency of the half toroidal type continuously variable transmission configured and operated as described above is ensured, and the inner surfaces 2a, 4a of the input side disk 2 and the output side disk 4 and the power rollers 8, 8 In order to secure the rolling fatigue life of the peripheral surfaces 8a, 8a, it is necessary to appropriately regulate the shape and dimensions (geometric parameters) of each part. Such geometric parameters that affect the performance of the half toroidal type continuously variable transmission include a cavity diameter D, a half apex angle θ ₀ , and a radius of curvature r ₀ . Each of these geometric parameters D, θ ₀ , and r ₀ will be described with reference to FIG.

The plurality of virtual straight lines representing the central axes of the pivots 5 and 5 (see FIGS. 1 to 4) for swingably displacing the trunnions 6 and 6 are tangent to the cavity diameter D. It is represented as the diameter of a virtual circle that can be drawn as
As shown in FIGS. 1 to 4, in the case of a structure in which a pair of trunnions 6, 6 are arranged in a cavity in parallel with each other, the cavity diameter D is equal to the distance between the central axes of the pivots 5, 5. I do. The radius of curvature r ₀ refers to the radius of curvature of the cross-sectional shape of the inner surfaces 2a and 4a of the input side disk 2 and the output side disk 4, and the center point of the radius of curvature r ₀ is:
It is a point O on an extension of the central axis of each of the pivots 5,5.
The half apex angle θ ₀ is defined as a portion where the point O and the peripheral surfaces 8a, 8a of the power rollers 8, 8 abut on the inner side surfaces 2a, 4a of the input side disk 2 and the output side disk 4 ( Virtual line α connecting the center point o of the traction contact part)
Is an angle formed between the power rollers 8 and 8 and the central axis β. Further, as represented by _{k 0 = (D / 2r 0} ) -1, k 0
Since the following numerical values are convenient for expressing the speed ratio of the half-toroidal type continuously variable transmission and the magnitude of spin at the traction contact portion, they are generally used as the above geometric parameters.

As publications defining such geometric parameters, those described in Japanese Utility Model Laid-Open No. Sho 62-158250 and Japanese Patent Publication No. 6-72563 are known. In Japanese Utility Model Laid-Open Publication No. Sho 62-158250, the half-vertical angle θ ₀ is set to 52.5 to 65 degrees, while in Japanese Patent Publication No. 6-72563, k ₀ ≧ 0.6,
It is described that θ ₀ ≧ 50 degrees and | ω _sp / ω ₁ | ≦ 0.3, respectively. Here, ω _sp is a spin angular velocity of a contact ellipse existing at a traction contact portion between the inner surfaces 2a, 4a of the disks 2, 4 and the peripheral surfaces 8a, 8a, and ω ₁ is the input side disk. 2 is the rotational angular velocity. By restricting the geometric parameters of the half-toroidal type continuously variable transmission to the above ranges, the durability of the thrust bearing supporting the power rollers 8, 8 is ensured, and the half-toroidal type continuously variable transmission is controlled. It is said to ensure the transmission efficiency of

[0017]

In the case of the half-toroidal-type continuously variable transmission described in each of the above publications, it is not always possible to secure a sufficient transmission efficiency. The reason will be described below. In the half toroidal type continuously variable transmission, the magnitude of the spin at the traction contact portion is determined by the geometric shapes of the input and output disks 2 and 4 and the power rollers 8 and 8. This spin is a rotational slip component in the contact elliptical surface of the traction contact portion, and is a loss because it is a slip in a direction unrelated to power transmission. Therefore, in the half toroidal type continuously variable transmission, if the spin is large, the power transmission efficiency is reduced, and the life is shortened due to the heat generated by the traction portion (the inner surfaces 2a, 4a of the input and output disks 2, 4 and 4). The rolling fatigue life of the peripheral surfaces 8a of the power rollers 8, 8 may be reduced.

When viewing the inventions described in the above publications on such a premise, in the invention described in Japanese Utility Model Laid-Open No. Sho 62-158250, the half toroidal shape is limited only by limiting the half apex angle θ _0. The cavity diameter D and the radius of curvature r ₀ of the cross-sectional shapes of the inner surfaces 2a and 4a of the input-side disk 2 and the output-side disk 4 that are the remaining two geometric parameters that determine the characteristics of the type continuously variable transmission are optimized. Is not considered. Therefore, it cannot be said that the transmission efficiency of the half toroidal type continuously variable transmission can be sufficiently increased.

Further, in the case of the invention described in Japanese Patent Publication No. 6-72563, an additive-free turbine oil is used as the lubricating oil stored in the casing 35 (FIG. 4) to lubricate the traction contact portion. Is assumed to be used. However, if mineral oil such as turbine oil is used for a traction drive device such as a half toroidal type continuously variable transmission, a large transmission capacity cannot be obtained. That is, for example, as described in “Idemitsu Tribo Review No. 12-1986” issued by Idemitsu Kosan Co., Ltd., the traction coefficient (μ) that affects the transmission efficiency at the traction contact portion differs depending on the oil type. Mineral oils such as turbine oils have a traction coefficient less than half that of traction oil, which is a synthetic oil developed exclusively for traction drives. This means that under the same contact pressing force, when using mineral oil, less than half of the power when using traction oil is transmitted. Therefore,
When a mineral oil is used as a lubricating oil, a large power cannot be transmitted in a half-toroidal type continuously variable transmission which needs to be installed in a limited installation space such as a transmission for an automobile. In view of such circumstances, the present invention secures excellent durability and allows for greater power transmission.
The present invention was invented to realize a half toroidal type continuously variable transmission having excellent transmission efficiency.

[0020]

The half toroidal type continuously variable transmission according to the present invention is configured as shown in FIGS. 3 and 4, for example, similarly to the above-mentioned conventional half toroidal type continuously variable transmission. That is, the half-toroidal continuously variable transmission of the present invention
The casing 35 has a casing 35 in which lubricating oil is stored. The input side disk 2 and the output side disk 4 are supported concentrically and rotatably inside the casing 35 with the inner side surfaces 2a and 4a facing each other. A plurality of trunnions 6, 6 are provided between the input side disk 2 and the output side disk 4 so as not to intersect with the central axes of the input side disk 2 and the output side disk 4. The pivots 5 and 5 are provided so as to be swingable about the pivots 5 and 5 which are located in a twisted position which is a position perpendicular to the direction of the central axis of. Displacement shafts 7, 7 are supported at the intermediate portions of the trunnions 6, 6 in such a manner as to protrude from the inner surfaces of the trunnions 6, 6, respectively. Power rollers 8, 8 are rotatably supported around portions of the displacement shafts 7, 7 protruding from the inner surfaces of the trunnions 6, 6, respectively. These power rollers 8 are sandwiched between the input disk 2 and the output disk 4.

The inner surfaces of the input-side disk 2 and the output-side disk 4 are concave surfaces each having a circular cross section.
The peripheral surfaces 8a, 8a of the power rollers 8, 8 are spherical convex surfaces. The peripheral surfaces 8a, 8a and the inner surfaces 2a, 4a of the disks 2, 4 are in contact with each other. As shown in FIG. 5 described above, each of these inner surfaces 2a,
The center point O of the curvature radius r ₀ of the cross-sectional shape of 4a is present on an extension line of the center axis of the pivot shafts 5, 5. The radius of curvature r 8a of the cross-sectional shape of the peripheral surfaces 8a, 8a of the power rollers 8, ₈ is slightly smaller than the radius of curvature r ₀ of the cross-sectional shape of each of the inner side surfaces 2a, 4a (r _8a <r ₀ ).

In particular, in the half toroidal type continuously variable transmission according to the present invention, the lubricating oil stored in the casing 35 has a traction coefficient of 0.06 at an oil temperature (oil supply temperature) of 100 ° C. It is a synthetic traction oil that is at least (preferably at least 0.07). Further, the cavity diameter described in the above-mentioned FIG.
₀ , the radius of curvature of the cross-sectional shape of the inner surfaces 2a, 4a of the disks 2, 4 is r _0, and k ₀ = (D / 2r ₀ ) −
1, the spin angular velocity of a contact ellipse existing at a contact portion between the inner surfaces 2a, 4a of the disks 2, 4 and the peripheral surfaces 8a, 8a of the power rollers 8, 8, is ω _sp , and the input side disk the second rotation angular velocity in the case of the ω _1, k ₀ ≧
0.5, θ ₀ ≧ 58 degrees, and | ω _sp / ω ₁ | ≦ 0.25. The traction coefficient is measured using a widely known two-cylinder tester or four-cylinder tester.

[0023]

The half-toroidal type continuously variable transmission of the present invention configured as described above transmits the rotational force between the input side disk 2 and the output side disk 4; The effect of changing the speed ratio between the two is the same as that of the conventionally known half toroidal type continuously variable transmission. In particular, in the case of the half toroidal type continuously variable transmission of the present invention, k ₀ ≧ 0.
5. By satisfying all of θ ₀ ≧ 58 degrees and | ω _sp / ω ₁ | ≦ 0.25, excellent durability is ensured, and excellent power transmission efficiency that enables larger power transmission is achieved. A half toroidal type continuously variable transmission can be realized.

Hereafter, k ₀ ≧ 0.5, θ ₀ ≧ 58 degrees, | ω
By satisfying all the conditions of _sp / ω ₁ | ≦ 0.25, it is possible to realize a half-toroidal type continuously variable transmission that has excellent durability and secures a large power transmission and has excellent transmission efficiency. I explain why. First, | ω _sp / ω ₁
A description will be given of | ≦ 0.25. As described above, in order to ensure the transmission efficiency and to ensure the durability of the inner surfaces 2a, 4a and the peripheral surfaces 8a, 8a constituting the traction contact portion, the spin generated at the traction contact portion is required. Need to be smaller. Therefore, in the case of the present invention,
| Ω _sp / ω ₁ | ≦ 0.25.

The reason why | ω _sp / ω ₁ | ≦ 0.25 is described with reference to FIG. FIG. 6 shows the characteristics of "Santo Truck 50", a type of traction oil, manufactured by Idemitsu Kosan Co., Ltd. This figure 6
Are obtained using a two-cylinder traction model tester as shown in FIG.
6, the vertical axis represents the traction coefficient μ, and the horizontal axis represents the slip ratio. The solid line connecting the □ marks is 2
Characteristic when the angle of intersection α between the contact surface of the cylinder and the rotation axis is 0 degree, the broken line connecting the mark △ indicates the characteristic when the angle is also 20 °,
The chain lines connecting the circles indicate the characteristics at 30 degrees, respectively. The larger the intersection angle α, the larger the spin generated at the contact point between the two cylinders.

As is apparent from FIG. 6, the traction characteristics (traction coefficient) change depending on the magnitude of the spin. As is clear from FIG. 6, when the spin is large (intersection angle α is large), the slip ratio for the same traction coefficient increases. An increase in the slip ratio means a decrease in transmission efficiency, which is not preferable for a traction type power transmission device such as a half toroidal type continuously variable transmission.

FIG. 8 shows the relationship between the magnitude of the spin and the slip ratio. FIG. 8 is read from the data of the experiment whose results are shown in FIG. 6 described above. As is clear from FIG. 8, when | ω _sp / ω ₁ | is larger than 0.25, the slip ratio sharply increases with the increase in spin.
In other words, the transmission efficiency is significantly reduced based on the increase in the spin. On the other hand, | ω _sp / ω ₁ |
In the case of 5 or less, the increase in the slip ratio is small even if the spin increases. Therefore, | ω _sp / ω ₁ | at a ≦ 0.25 area, as long as driving a half-toroidal type continuously variable transmission, spin never lead to a large power loss.

Next, a geometrical shape for _satisfying | ω _sp / ω ₁ | ≦ 0.25, that is, a cavity diameter D, a half apex angle θ ₀ ,
The value to be taken as the radius of curvature r ₀ of the cross-sectional shape of the inner surfaces 2a, 4a of the disks 2, 4 will be described. First, the gear ratio i between the input side disk 2 and the output side disk 4 constituting the half toroidal type continuously variable transmission is shown in FIG.
As is apparent from the above, i = r ₃ / r ₁ = {1 + k ₀ −cos (2θ ₀ −ψ)} / (1 + k ₀ −cos}) (1) Also, the spin angular velocity ω _{sp at the} traction contact portion is input. the ratio of the rotational angular velocity omega ₁ of the side disks 2, spin ratio | ω _sp / ω ₁ | _{is, | ω sp / ω 1 |} = | {sinψ · sinθ 0 - (1 + k 0 - cosψ) · cosθ 0} / Sin θ ₀ | −−− (2) In the half toroidal type continuously variable transmission, the range of the inclination angle 採 that can be taken in relation to the thickness of the shaft and the thickness required at the top of the disk is about ψ = 20 ° to (2θ ₀ -20 °).

Absolute value of spin ratio ω _sp / ω ₁ | ω _sp /
ω ₁ | becomes the maximum at the time of maximum deceleration (ψ = 20 degrees) or maximum acceleration (最大 = 2θ ₀ -20 degrees).
When ψ = 20 degrees or ψ = 2θ ₀ -20 degrees, | ω _sp
/ Ω ₁ | should not exceed 0.25 described above.
The point at which | ω _sp / ω ₁ | is 0.25 is represented by k ₀ on the vertical axis.
Is plotted on a coordinate plane representing the half vertex angle θ ₀ on the horizontal axis, as shown in FIG. If the values of k ₀ and θ ₀ are within the range of the oblique line in FIG. 9, | ω _sp / ω
₁ | ≦ 0.25 is satisfied. However, in the range shown by oblique lines in FIG. 9, the region where k ₀ and the half apex angle θ ₀ can be taken is too wide, and when designing the half toroidal type continuously variable transmission, these k ₀ and It is difficult to set the half apex angle θ ₀ .

Therefore, in the present invention, these k ₀ and the half apex angle θ
The selection range of ₀ is limited to facilitate selection of parameters. From the gear ratio i determined by the above equation (1),
The width of the gear ratio that can be designed in the half toroidal type continuously variable transmission (maximum reduction ratio × maximum speed increase ratio = i ² ) can be calculated. Then, if the values of k ₀ and θ ₀ existing on the two solid lines shown in FIG. 9 are applied to the calculated value of the gear ratio width i ² , ω _sp / ω ₁ = 0.25 Speed ratio width i ^{2 when}
And the gear ratio width i ² when ω _sp / ω ₁ = −0.25
Can be calculated. Then, the above k ₀ and the half apex angle θ ₀ are these two values (ω _sp / ω ₁ = 0.25
K ₀ if it is, theta ₀ and ω _sp / ω ₁ = k ₀ if a -0.25, if between _{θ 0) | ω sp / ω} 1 | ≦
This means that a high-efficiency half-toroidal-type continuously variable transmission that satisfies 0.25 can be designed.

The ratio R of the two speed ratio widths described above, that is, the speed ratio width i when R = (ω _sp / ω ₁ = 0.25)
² ) The ratio R expressed by ( ² ) / (transmission ratio width i ² when ω _sp / ω ₁ = −0.25) is an index indicating the degree of freedom when designing a half toroidal type continuously variable transmission. Become. FIG. 10 shows the relationship between the half apex angle θ ₀ and the ratio R. As is apparent from FIG. 10, if the half apex angle θ ₀ is set to θ ₀ ≧ 58 °, the amount of change in the ratio R can be suppressed small, and the degree of freedom in design is limited. It can be seen that the parameters for the half vertex angle θ ₀ and the above k ₀ can be easily selected.

FIG. 11 shows the relationship between k ₀ and the ratio R. As is apparent from FIG.
_0, if k ₀ ≧ 0.5, still to be able to suppress the variation of the ratio R, for limited freedom of design, the semi-apex angle theta ₀
And the selection of the parameter k ₀ is facilitated.

To summarize the above, the half vertex angle θ ₀ and k ₀
By limiting the value of k ₀ represented by == (D / 2r ₀ ) -1 to the ranges of θ ₀ ≧ 58 degrees and k ₀ ≧ 0.5, | By ensuring that _sp / ω ₁ | ≦ 0.25 (while keeping the spin low), a highly efficient half-toroidal-type continuously variable transmission can be realized.

[0034]

The half toroidal type continuously variable transmission according to the present invention is constructed and operates as described above, so that it has excellent durability and excellent power transmission efficiency capable of transmitting more power. , A practical half-toroidal-type continuously variable transmission can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a half toroidal type continuously variable transmission to which the present invention is applied in a state of maximum deceleration.

FIG. 2 is a schematic side view similarly showing a state at the time of maximum speed increase.

FIG. 3 is a sectional view showing an example of a specific structure of a half-toroidal type continuously variable transmission.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a schematic side view of a main part for explaining geometric parameters of each part.

FIG. 6 is a diagram showing characteristics of a typical traction oil.

FIG. 7 is a schematic diagram showing the principle of a two-cylinder testing machine used to determine the characteristics of FIG.

FIG. 8 is a diagram showing a relationship between a spin ratio and a slip ratio.

FIG. 9 shows that the absolute value of the spin ratio is 0.25,
The k ₀ on the vertical axis, the half apex angle theta ₀ on the horizontal axis, and plotted on a coordinate plane expressed respectively FIG.

FIG. 10 is a diagram showing a relationship between a half apex angle θ ₀ and a speed ratio width ratio R.

FIG. 11 shows a relationship between a value k ₀ represented by (D / 2r ₀ ) -1 and a ratio R of a speed ratio width from a cavity radius D and a curvature radius r ₀ of a cross-sectional shape of an inner surface of each disk. FIG.

[Explanation of symbols]

 Reference Signs List 1 input shaft 2 input side disk 2a inner surface 3 output shaft 4 output side disk 4a inner surface 5 pivot 6 trunnion 7 displacement shaft 8 power roller 8a peripheral surface 9 loading cam device 10 loading cam 11 retainer 12 roller 13, 14 cam surface Reference Signs List 15 input shaft 16 needle bearing 17 through hole 18 locking groove 19 retaining ring 20 flange 21 output gear 22 key 23 support plate 24 circular hole 25 support shaft 26 pivot shaft 27 radial needle bearing 28 radial needle bearing 29 thrust ball Bearing 30 Thrust needle bearing 31 Outer ring 32 Drive rod 33 Drive piston 34 Drive cylinder 35 Casing

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J051 AA03 BA03 BE09 EC07 FA02 3J063 AA02 AB33 AC03 BA11 CB36 XD03 XD15 XD72 XE02 4H104 EA01A EB02 LA20 PA03

Claims (1)

[Claims] 1. An input-side disk rotatably supported concentrically with a casing, lubricating oil stored in the casing, and with the inner surfaces facing each other inside the casing. And the output side disk and the center axis of the input side disk and the output side disk but do not intersect, but swing about a pivot axis at a twist position which is a position perpendicular to the direction of the center axis of the both side disks. A trunnion, a displacement shaft supported at a middle portion of the trunnion so as to protrude from the inner surface of the trunnion, and rotatably supported around a portion of the displacement shaft protruding from the inner surface of the trunnion. A power roller sandwiched between the input side disk and the output side disk, and the inner surfaces of the input side disk and the output side disk. Is a concave surface having an arc-shaped cross section, the peripheral surface of the power roller is a spherical convex surface, and the half toroidal type continuously variable transmission in which this peripheral surface and the inner surfaces of both disks are in contact with each other. In the above, the lubricating oil is
The traction coefficient is 0.06 when the oil temperature is 100 ° C.
The synthetic traction oil described above, and D is a cavity diameter that is a diameter of a virtual circle that can draw a plurality of virtual straight lines representing the central axes of the pivots as tangents thereof,
The angle formed by a virtual straight line connecting the center point of the radius of curvature of the inner surface of each disk and the center point of the portion where the peripheral surface of each power roller comes into contact with the inner surface of each disk with the center axis of the power roller , Θ ₀ , the radius of curvature of the cross-sectional shape of the inner surface of each disk is r _0, and k ₀
= (D / 2r ₀ ) −1, the spin angular velocity of the contact ellipse existing at the contact portion between the inner surface of each of the disks and the peripheral surface is ω _sp, and the rotational angular velocity of the input-side disk is ω ₁
Where k ₀ ≧ 0.5, θ ₀ ≧ 58 degrees, | ω _sp /
A half toroidal type continuously variable transmission characterized by satisfying all ω ₁ | ≦ 0.25.