JP2003269557A - Power roller supporting structure for toroidal-type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To position a link connecting a trunnion for supporting a power roller in a direction crossing a trunnion axis against a spherical joint part of a fixed link post without backlash. <P>SOLUTION: The outer diameter of a link post (spherical joint) 17 fixed to a servo piston body 15 (transmission case) is larger than the inner radious of a cylinder hole 8b of a link 8. In a cavernous area formed in the spherical joint part of the link post 17, a vertical slit 17b in an axial direction of the cylinder hole 8b is formed in the spherical joint part of the link post 17. When the spherical joint part of a link post 17 is fitted in the cylinder hole 8b, the spherical joint part is fitted in the cylinder hole 8b with elastic deformation in a radially inward direction of the cylinder hole 8b, so that it is fitted in a pre-loading state. Therefore, even if the sizes of the spherical joint part of the link post 17 and the cylinder hole 8b are not, strictly managed, a backlash does not occur in the fitting part between them. The position accuracy of the link 8 against the servo piston body 15 (transmission case) is enhanced inexpensively and surely to improve speed control performance. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power roller support structure for a toroidal type continuously variable transmission, and more particularly, to a link for connecting trunnions that rotatably support the power roller.
The present invention relates to an improvement proposal that improves gear shift control performance by allowing the gearbox to be mounted without play.

[0002]

2. Description of the Related Art A toroidal continuously variable transmission normally has a pair of power rollers between input and output disks arranged coaxially.
The pair of power rollers are arranged on both sides of the rotation axis of the input / output disk and are rotatably supported by the individual trunnions. Upon transmission, the power roller is squeezed between the input and output disks by a force corresponding to the transmission torque, and the power roller transfers the power between the input and output disks by shearing the oil film according to the squeezing pressure.

Therefore, in order to prevent the power roller from being ejected between the input and output disks due to the thrust in the direction of being ejected between the input and output disks due to the above-mentioned clamping force, the power rollers are individually rotatable. The upper ends and the lower ends of the trunnions supported by the above are connected to each other by links.

When shifting, each trunnion is driven by a servo piston from the non-shift position where the rotation axis of the power roller intersects with the rotation axis of the input / output disk in the same phase (same shift) in the swing axis direction orthogonal to the rotation axis of the power roller. By synchronously offsetting (in the direction), tilting of the trunnion and the power roller about the swing axis can be caused to shift.

For this reason, both links and each trunnion are connected by a joint structure so that the above-mentioned offset and tilting can be performed, and each trunnion forming a pair so that each link can swing with the above-mentioned offset. Support the transmission case at the center of the space. By the way, in the case of swingably supporting the link to the transmission case in the center between the trunnions, conventionally, as described in, for example, JP-A-1-216158, a spherical joint on a link post fixed to the transmission case is used. By fitting with the cylindrical hole provided in the link, the link is positioned in a direction crossing the trunnion axis (pivoting axis) while enabling the above swing.

[0006]

However, in the prior art, strict dimensional control is required in order to prevent looseness in the fitting portion between the spherical joint and the cylindrical hole, which is disadvantageous in terms of cost. The fact is that the above-mentioned backlash cannot be completely eliminated. By the way, if there is play in the fitting part between the spherical joint and the cylindrical hole, when the direction of the transmission torque is switched due to the transition from drive running to engine braking, the link is displaced by the above-mentioned play. There has been a problem that a sudden change in the gear ratio is caused and the shift control performance is deteriorated.

According to the present invention, a power roller supporting structure is provided in which the looseness never occurs in the fitting portion between the spherical joint and the cylindrical hole without strict dimensional control as in the conventional case. It is an object of the present invention to improve the shift control performance inexpensively and surely and solve the above problem.

[0008]

To this end, the power roller supporting structure of the toroidal type continuously variable transmission according to the present invention has a cylindrical hole on the link side and a spherical surface on the transmission case side as described in claim 1. Fit the joint with the pre-loaded state,
As a result, it is possible to prevent backlash between them without strict dimensional control, and to improve the positioning accuracy of the link with respect to the transmission case inexpensively and reliably.

[0009]

According to the structure of the present invention, since the cylindrical hole on the link side and the spherical joint on the transmission case side are fitted in a pre-loaded state, the spherical joint and the cylindrical hole are strictly dimensioned. Even if it is not managed, there is no backlash in the fitting portion between them, and it is possible to improve the positioning control accuracy of the link with respect to the transmission case at low cost and surely to improve the shift control performance.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a toroidal-type continuously variable transmission equipped with a power roller supporting structure according to an embodiment of the present invention, and FIGS. 2 and 3 show an enlarged view of essential parts of the present invention. .

As shown in FIG. 1, the toroidal type continuously variable transmission includes an input disk 1 and an output disk coaxially opposed to the input disk 1 (not shown because it is located in front of the input disk 1 in the drawing). The power rollers 2 and 3 between these input / output disks are the main constituent elements. The power rollers 2 and 3 are interposed between the input / output disks so as to transmit power by shearing an oil film between the input / output disks, and are arranged on opposite sides of the rotation axis O ₃ of the input / output disks.

The power rollers 2 and 3 are rotatably supported by individual trunnions 4 and 5, respectively.
5 is arranged so that its axis (oscillation axis) O ₂ extends at right angles to the input / output disk rotation axis O ₃ .
The trunnions 4 and 5 have upper ends adjacent to each other on the same side (upper side near the top wall of the transmission case 6) connected to the plate-like upper link 7, and further adjacent to each other on the lower side. The matching lower ends are also connected to the plate-like lower link 8.

At the time of connecting these joints, the plate-like links 7, 8
The outer spherical surfaces of the spherical joints 9 and 10 are fitted into the openings 7a and 8a formed at both ends of the spherical joints 9 and 10 and the trunnions 4 and 5, respectively.
The rotary bearings 11 and 12 are interposed between the upper and lower ends of the trunnions 4 and 5, and the plate-shaped links 7 and 7 are connected to the trunnions 4 and 5 by a composite joint (joint structure).
It is articulated so as to be rotatable with respect to 8 and capable of changing the crossing angle. The plate-shaped links 7 and 8 hold the trunnions 4 and 5 in the direction of the power roller rotation axis O ₁ so that the power rollers 2 and 3 will not be ejected from between the input and output disks even if they are pinched. .

Servo pistons 13 and 14 are fixed to the lower ends of the trunnions 4 and 5, and these servo pistons are slidably fitted in a common servo piston body 15. The servo piston body 15 is installed horizontally across the bottom opening of the transmission case 6 so as to close it, and the bolt 16 is attached.
To the transmission case 6.

Between the lower ends of the trunnions 4 and 5, a spherical joint type link post 17 is mounted upright on the servo piston body 15 (transmission case 6), and the transmission case 6 is located between the upper ends of the trunnions 4 and 5. The spherical joint type link post 18 is attached to the top wall of the above to stand upright.

A cylindrical hole 8b into which the link post 17 is fitted is formed in the central portion of the plate-like lower link 8, and the fitting causes the lower link 8 to move in the direction of the disk rotation axis O ₃ and the power roller rotation axis O _1. In both directions (so
The power roller can be swung in a state of being positioned (in all directions across the swing axis O ₂ ).

A link is provided at the center of the plate-like upper link 7.
A cylindrical hole 7b into which the post 18 is fitted is formed and
The upper link 7 from the disk rotation axis O_ThreeDirection
And power roller rotation axis O₁In both directions (follow
Power roller swing axis O _TwoAll directions across
(2) It is possible to swing while it is positioned.

According to the above power roller support structure, the plate-like links 7 and 8 can be displaced in the longitudinal direction of the trunnions 4 and 5, so that there is a risk that they will interfere with the parts other than the trunnions 4 and 5 to hinder their movement. There is. In order to eliminate this concern, it is necessary that the plate-shaped links 7 and 8 are displaced in the same direction as trunnions 4 and 5.
It is better to regulate by Because of this, trunnion 4,
5, stepped portions 4a and 5a provided to receive the spherical joint 9 and the rotary bearing 11 at the upper end of the plate 5, and the plate-like upper link 7
The plate-shaped upper link 7 is sandwiched between the upper ends of the trunnions 4 and 5 protruding from the opening 7a of the trunnion 4 and 5 and the stopper plate 20 attached by the bolts 19, so that the plate-shaped upper link 7 is displaced in the longitudinal direction of the trunnion. regulate.

Further, the plate-like lower link 8 is attached to the trunnion 4,
As for the configuration for restricting the position with respect to 5, the trunnions protruding from the openings 8a of the plate-like lower link 8 and the step portions 4b and 5b provided at the lower ends of the trunnions 4 and 5 to receive the spherical joint 10 and the rotary bearing 12 are provided. The plate-like lower link 8 is sandwiched between the tilt-synchronizing wire pulleys 21 fixed to the lower ends of the plates 4 and 5, and these restrict the plate-like lower link 8 from being displaced in the trunnion longitudinal direction. However, a gap is set between the plate-like links 7 and 8 and the portions sandwiching them as described above, to such an extent that the trunnions 4 and 5 and the plate-like links 7 and 8 do not obstruct this when the crossing angle changes. Of course.

The transmission operation and the speed change action of the toroidal type continuously variable transmission will be described below. In the toroidal type continuously variable transmission, the engine rotation is input to the input disk 1 via a loading cam (not shown). The loading cam generates thrust corresponding to the transmitted torque to urge the input disc 1 toward the output disc, and presses the power rollers 2 and 3 between these input and output discs. Thus, the rotation to the input disk 1 is transmitted to the power rollers 2 and 3 which are in contact with the input disk 1 via the oil film, and the power rollers 2 and 3 are connected to the axis O
_When rotated around ₁ , the power rollers 2 and 3 can transmit the rotation to an output disk that is in contact therewith via an oil film, and power can be taken out therefrom.

During the transmission, the power rollers 2 and 3 are synchronized by the servo pistons 13 and 14 via the trunnions 4 and 5 in the same phase in the direction of the swing axis O ₂ orthogonal to the power roller rotation axis O ₁ . When the power roller rotation axis O ₁ is offset from the disk rotation axis O ₃ by making a stroke from the non-shift position shown in the figure, the power rollers 2 and 3 are tilted in the same phase synchronously around the swing axis O _2. . As a result, the radius of the contact locus circle of the power rollers 2 and 3 with respect to the input / output disks continuously changes, and the transmission ratio (gear ratio) between the input / output disks can be continuously changed. When the transmission ratio reaches the target transmission ratio, the target transmission ratio can be maintained by returning the power rollers 2 and 3 to the initial stroke position where the offset is 0.

By the way, in the present embodiment, the links 8 and 7 are fixed between the trunnions 4 and 5 on the servo piston body 15 (transmission case 6) and the top wall of the transmission case 6, respectively. Link posts 17 and 18 and cylindrical holes 8b and 7b provided in the links 8 and 7.
2 and FIG. 3 are adopted for positioning in a direction traversing the trunnion axis O ₂ while allowing the transmission case 6 to swing with respect to the transmission case 6.

2 and 3 show a fitting structure of a spherical joint type link post 17 relating to the lower link 8 and a cylindrical hole 8b provided in the link 8, which shows a spherical joint portion of the link post 17. As shown in FIG. The outer diameter is made larger than the inner diameter of the cylindrical hole 8b. In order to fit the spherical joint portion of the link post 17 into the cylindrical hole 8b, a blind hole-shaped cavity 17a is formed in the spherical joint portion of the link post 17, and the link post 17 is formed in the cavity region. A vertical slit 17b extending in the axial direction of the cylindrical hole 8b is formed in the spherical joint portion. It is preferable that a plurality of vertical slits 17b are provided as one set and these are arranged at equal intervals in the circumferential direction of the cylindrical hole 8b.

Thus, when the spherical joint portion of the link post 17 is fitted into the cylindrical hole 8b, the spherical joint portion is fitted into the cylindrical hole 8b while being elastically deformed radially inward of the cylindrical hole 8b. This means that the cylindrical hole 8b and the link post 1
The fitting with the spherical joint portion 7 can be performed in a preloaded state. Therefore, even if the spherical joint portion of the link post 17 and the cylindrical hole 8b are not strictly dimensioned, no looseness will occur in the fitting portion between them.
The positioning accuracy of the link 8 with respect to the transmission case 6 can be enhanced inexpensively and reliably, and the shift control performance can be improved.

The spherical post type link post 17 relating to the lower link 8 and the cylindrical hole 8b provided in the link 8 have a fitting structure of a spherical post type link post 18 relating to the upper link 7, It goes without saying that the same action and effect can be obtained by directly applying the same to the fitting structure with the cylindrical hole 7b provided in the link 7.

Furthermore, the cavities 17a and the vertical slits 17b shown in FIGS. 2 and 3 do not necessarily have to be a combination of the two, and even if each is used alone, the cavities 1 are also used.
Even without both 7a and the vertical slit 17b, the spherical joint portion of the link post 17 can be fitted into the cylindrical hole 8b under elastic deformation. In these cases, the rigidity of the spherical joint portion of the link post 17 becomes high in the radial direction of the cylindrical hole 8b, so that the fitting work between the two becomes difficult, but the positioning rigidity of the link 8 with respect to the transmission case 6 increases and the gear shift operation is performed. Further improvement of control performance can be realized.

In any case, as in the above embodiment, the outer diameter of the spherical joint portion of the link post 17 (18) is made larger than the inner diameter of the cylindrical hole 8b (7b) so that the spherical joint portion is elastically deformed. Link post 1
When the spherical joint portion 7 (18) is fitted in the cylindrical hole 8b (7b) in a preloaded state, no change is required in the work of attaching the links 7 and 8 to the transmission case 6, so that the conventional assembly The work procedure can be followed as it is, and the structure is such that the outer diameter of the spherical joint portion of the link post 17 (18) is made larger than the inner diameter of the cylindrical hole 8b (7b), and if necessary, the cavity 17a. And / or the above-mentioned effects can be achieved with a simple and inexpensive structure in which only the vertical slit 17b is provided.

FIG. 4 shows another embodiment of the present invention. In this embodiment, the link post 17 is mounted on the bottom of the blind hole-shaped cavity 17a in the spherical joint of the link post 17 by means of a bolt 23 which is seated via a washer 22. It is attached to the servo piston body 15 (transmission case 6). Therefore bolt 2
3 extends in the axial direction of the cylindrical hole 8b and penetrates the link post 17 from the bottom of the cavity 17a, and then is screwed into the servo piston body 15 (transmission case 6), and the head of the bolt 23 and the bottom of the cavity 17a. The above washer 22 is interposed between and.

By the way, the bolt insertion hole of the link post 17 has an end portion 17c opened at the bottom of the cavity 17a.
The diameter of the bolt 23 is tapered toward the bottom, and the end 23a of the bolt 23 closer to the head is also tapered. Thus, the bolt 23 is inserted into the link post 17 from the bottom of the cavity 17a and the servo piston body 15 is inserted.
When the link post 17 is screwed into the (transmission case 6) and the link post 17 is attached to the servo piston body 15 (transmission case 6), the spherical joint portion of the link post 17 is fitted into the cylindrical hole 8b in a preloaded state as follows. Can be made.

That is, when the bolt 23 is screwed in, the tapered end portion 23a near the head of the bolt 23 cooperates with the similar tapered bolt insertion hole end portion 17c to perform a wedge action, thereby forming a spherical surface of the link post 17. The joint portion is elastically deformed so that the outer diameter is increased, and by this elastic deformation, the spherical joint portion of the link post 17 can be fitted into the cylindrical hole 8b in a preloaded state, and the same effect as the above can be achieved. .

The amount of deformation when the spherical joint portion of the link post 17 is elastically deformed as described above is determined by the screwing amount of the bolt 23, and this screwing amount is determined by the washer 2
It is possible to adjust the preload state by adjusting the plate thickness of No. 2 to adjust the elastic deformation amount of the spherical joint portion of the link post 17 to adjust.

When it is required to easily deform the spherical joint portion of the link post 17 when elastically deforming,
As described above with reference to FIGS. 2 and 3, the link post 1
Cavities 17a and vertical slits 17b can be selectively formed in the spherical joint portion of No. 7.

By the way, in the present embodiment, the link post 17 fitted in the cylindrical hole 8b in a preloaded state.
Since the spherical joint portion of R is made to have high rigidity in the diameter reducing direction by the tapered end portion 23a near the head of the bolt 23, the positioning rigidity of the link 8 with respect to the transmission case 6 is further increased as compared with the above-described embodiment. Therefore, the shift control performance can be further improved and the shift control performance can be further improved.

No matter which structure is shown in FIGS. 2, 3 or 4, the vertical slit 17b provided in the spherical joint portion of the link post 17 has a surface (including the axis O ₂ of the trunnions 4 and 5). It is preferable to dispose at a position deviating from the inside (cross section of FIG. 1). Since the spherical joint portion of the link post 17 receives a large load in the direction along the surface, when the vertical slit 17b provided in the spherical joint portion of the link post 17 is arranged in this surface, stress concentrates here. Although the durability of the spherical joint portion of the link post 17 may be reduced, as described above, the vertical slit 17b is located at a position deviated from the plane (cross section in FIG. 1) including the axis O ₂ of the trunnions 4 and 5. By arranging, it is possible to eliminate such a risk.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a toroidal type continuously variable transmission including a power roller support structure according to an embodiment of the present invention.

FIG. 2 is a detailed cross-sectional view showing a fitting structure of a lower link and a link post in the same power roller support structure as a cross section taken along the line II-II in FIG.

FIG. 3 is a plan view of a link post in the power roller support structure.

FIG. 4 is a detailed cross-sectional view showing a fitting structure of a lower link and a link post in a power roller supporting structure according to another embodiment of the present invention.

[Explanation of symbols]

1 input disk 2 power rollers 3 power rollers 4 trunnions 5 trunnion 6 transmission case 7 Upper link 7b cylindrical hole 8 Lower Link 8b cylindrical hole 13 Servo piston 14 Servo piston 15 Servo piston body 16 volt 17 Link post (spherical joint) 17a cavity 17b slit 17c Tapered end of bolt insertion hole 18 Link post (spherical joint) 22 washers 23 bolts 23a Bolt head side tapered end

Claims (8)

[Claims] 1. A pair of power rollers for transmitting and receiving power by shearing an oil film according to a pinching force between coaxially arranged input and output disks are rotatably supported on individual trunnions, and adjacent one ends of these trunnions are provided. A link that connects the parts and the other ends to each other is provided, and by fitting the spherical joint fixed to the transmission case and the cylindrical hole provided in the link between the trunnions,
In a toroidal type continuously variable transmission that is positioned in a direction transverse to the trunnion axis while being swingable with respect to the transmission case, the cylindrical hole of the link and the spherical joint are fitted in a preloaded state, and the positioning accuracy is set. The power roller support structure of the toroidal type continuously variable transmission, which is characterized by improving 2. The power roller support structure according to claim 1, wherein an outer diameter of the spherical joint is larger than an inner diameter of the cylindrical hole, and the spherical joint is elastically deformed to fit into the cylindrical hole. A power roller support structure for a toroidal type continuously variable transmission, which is configured to obtain a preloaded state. 3. The power roller support structure for a toroidal type continuously variable transmission according to claim 2, wherein a cavity is set in the spherical joint to enable the elastic deformation. . 4. The power roller support structure according to claim 2, wherein a slit extending in the axial direction of the cylindrical hole is formed in the spherical joint to facilitate the elastic deformation. Power roller support structure for toroidal type continuously variable transmission. 5. The power roller support structure according to claim 1, wherein the spherical joint is fixed to a transmission case with a bolt extending in an axial direction of the cylindrical hole, and the bolt and the spherical joint are inserted through the bolt. Between the hole and the hole, a tapered surface for elastically deforming the spherical joint so as to increase the outer diameter by the tightening force of the bolt is set, and the elastic deformation causes the preload state to be obtained. Power roller support structure for the speed change gear. 6. The power roller support structure according to claim 5, wherein a slit extending in the axial direction of the cavity or the cylindrical hole is selectively formed in the spherical joint,
A power roller support structure for a toroidal type continuously variable transmission, characterized in that elastic deformation of the spherical joint is facilitated. 7. The power roller support structure according to claim 5, wherein the bolt is tightened through a washer, and the elastic deformation amount of the spherical joint due to the tapered surface is adjusted by adjusting the plate thickness of the washer. A power roller support structure for a toroidal type continuously variable transmission, which is characterized in that 8. The power roller support structure according to claim 4, 6 or 7, wherein the slit provided in the spherical joint is arranged at a position out of a plane including both trunnion axes. Power roller support structure for continuously variable transmission.