JP2006118540A - Disc/roller type continuously variable transmission using trunnion and v-link ring for supporting roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disc/roller type continuously variable transmission having three rollers pushed between a pair of discs, eliminating the need for or reducing the weight of triple links which support a trunnion at its adjacent ends and hold a V-link. <P>SOLUTION: Adjacent ends of the trunnion are connected to each other via legs 20a, 20c, 22a, 22b, 28b, 28c of V-links 20, 22, 28 and radial/thrust bearings 24, 26, 30, 32, 34, 36, 64, 66, 68, 70, 72, 74 in a ring shape to develop hoop tension which allows the tilting of rollers 12a, 12b, 12c to a pair of discs 10. Thus, the rollers 12a, 12b, 12c are pushed between the pair of discs and outward force in the radial direction of the discs on the rollers 12a, 12b, 12c is supported by the hoop operation of the ring. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a disk / roller type continuously variable transmission, and more particularly to an improvement of a gear ratio changing mechanism thereof.

  As one of continuously variable transmissions, a pair of disks having an operating surface whose radius changes along an axis, and a plurality of rollers pressed between the operating surfaces of the pair of disks coaxially opposed to each other And a rotational force is transmitted between the pair of disks via the rollers, and the center axis of each roller is displaced with respect to the center axis of the pair of disks. 2. Description of the Related Art A disk / roller type continuously variable transmission is known that changes the speed ratio of rotational force transmitted between the pair of disks by causing the disk to tilt relative to the disk. In this case, since the working surface of the disk whose radius changes along the axis is usually a part of the toroidal curved surface, this type of disk / roller type continuously variable transmission is generally called a toroidal continuously variable transmission. Yes.

Regarding the disk / roller type continuously variable transmission as described above, many invention proposals have been made so far regarding the detailed structure based on the basic structure, but most of them have two rollers between a pair of disks. This is a two-roller type provided 180 degrees apart from each other. However, there is also known a three-roller type in which three rollers are provided 120 degrees apart from each other between a pair of disks. Also, for example, as shown in the following Patent Documents 1 and 2 Invention proposals have been made.
JP-A-8-14350 JP-A-8-135747

  As described in the above-mentioned publication, in the conventional three-roller type disk / roller type continuously variable transmission, the adjacent ends of the trunnion have three roots where two legs meet. Each leg portion of the V-shaped link pivotally supported by the crotch link is connected by a radial bearing.

  FIG. 3 attached herewith is a diagram schematically showing the basic structure of such a conventional three-roller disk / roller type continuously variable transmission. In the figure, reference numeral 10 denotes one of a pair of disks each having an operating surface whose radius changes along the axis, and a point 10C is a view of the central axis of the disk along the disk. The three rollers 12a, 12b, and 12c are pressed and held between the pair of discs while the working surfaces of the pair of discs face each other, and are supported by the trunnions 14a, 14b, and 14c, respectively, and transmit rotational force between the pair of discs. It is supposed to be. The rollers 12a, 12b, and 12c are respectively supported by the trunnions via radial / thrust bearings 16a, 16b, and 16c and eccentric shafts 18a, 18b, and 18c.

  The trunnion 14a is a radial bearing 24 that is concentrically aligned with each other by one leg 20a of the V-shaped link 20 and one leg 22a of the V-shaped link 22 on both sides of the roller bearing that carries the eccentric shaft 18a with respect to the roller 12a. 26 is supported. Similarly, the trunnion 14b is a radial that is concentrically aligned by the other leg portion 22b of the V-shaped link 22 and the one leg portion 28b of the V-shaped link 28 on both sides of the roller bearing portion that carries the eccentric shaft 18b with respect to the roller 12b. It is supported via bearings 30 and 32. Similarly, the trunnion 14c is a radial that is concentrically aligned by the other leg portion 28c of the V-shaped link 28 and the other leg portion 20c of the V-shaped link 20 on both sides of the roller bearing portion that carries the eccentric shaft 18c with respect to the roller 12c. It is supported via bearings 34 and 36. Thus, the trunnions 14a, 14b, and 14c are supported on both sides of the roller support portion by the V-type links 20 and 22, the V-type links 22 and 28, and the V-type links 28 and 20, respectively. Since 24, 26, 30, 32, 34, and 36 are incorporated, it is possible to rotate around the connecting portion with the V-shaped link, and each roller carried by each trunnion is moved with respect to a pair of disks. It can be tilted.

  The V-shaped links 20, 22, and 28 are pivotally supported by the leg portions 38a, 38b, and 38c of the trifurcated link 38 via the pivot shafts 40a, 40b, and 40c, respectively. The trifurcated link 38 has leg portions 38a, 38b, and 38c and an annular portion 38d that supports the base portion thereof, and pins 42a, 42b, and 42c at the distal end portions of the leg portions 38a, 38b, and 38c, and the housing of the transmission. 44 is supported.

  The trunnion 14a is displaced along the alignment direction of the radial bearings 24 and 26 that are concentrically aligned by a cylinder / piston hydraulic actuator 46a supported by the housing 44 at one end thereof. Is positioned at a normal position where the central axis 48a intersects the disk central axis 10C, and is temporarily displaced from the normal position to either side in accordance with the increase or decrease of the transmission ratio only when the transmission ratio is changed. It has become. Similarly, the trunnion 14b is displaced along the alignment direction of the radial bearings 30 and 32 concentrically aligned by a cylinder / piston hydraulic actuator 46b supported by the housing 44 at one end thereof. The roller 12b is positioned at a normal position where its central axis 48b intersects the disk central axis 10C, and is temporarily displaced from the normal position to either side according to the increase or decrease of the gear ratio only when the gear ratio is changed. It has become so. Similarly, the trunnion 14c is displaced along the alignment direction of the radial bearings 34 and 36 concentrically aligned by a cylinder / piston hydraulic actuator 46c supported by the housing 44 at one end thereof. The roller 12c is positioned at a normal position where its center axis 48c intersects the disk center axis 10C, and is temporarily displaced from the normal position to either side according to the increase or decrease of the speed ratio only when the speed ratio is changed. It has become so.

  Further, the connection relationship between the trunnions 14a, 14b, 14c and the V-shaped links 20, 22, 28 is stably maintained in a normal state as shown in the drawing, that is, for example, the V-shaped link 22 is connected to the trunnions 14a, 14b. In order to prevent only the V-shaped link 22 from tilting leftward or rightward from the normal posture shown in the figure by sliding in the axial direction of the radial bearings 26 and 30 at the connecting portion, the trunnion 14a, Thrust bearings 50, 52, 54, 56, 58, 60 are further provided at the connecting portions of 14 b, 14 c and the V-shaped links 20, 22, 28. Such a thrust bearing has an arcuate shape in which the trunnion is generally curved outward at the roller bearing portion, and has shoulder portions 62af, 62ar, 62bf, 62br, 62cf, 62cr in the vicinity of the connecting portion with the V-shaped link, Since the cross-section of the trunnion is increased at the shoulder, it is generally incorporated between the shoulder and the leg of the V-shaped link, and each trunnion is a leg of two V-shaped links. It is pressed in the axial direction between the parts via a thrust bearing.

  The displacement of the roller center axes 48a, 48b, 48c relative to the disk center axis 10C for changing the transmission ratio is determined by the actuator 46a. 46b and 46c are simultaneously operated in the same direction. At this time, each V-shaped link tilts around a pivot point by pivots 40a, 40b, and 40c from a normal neutral posture as shown in accordance with the displacement of the actuator, and at this time, radial bearings 24, 26, 30, 32, and 34 , 36 and the thrust bearings 50, 52, 54, 56, 58, 60 are subjected to inclined displacement, but the roller center axes 48a, 48b, 48c with respect to the disk center axis 10C for changing the transmission gear ratio. The displacement is extremely small, and the angle of the above-described tilt displacement is very small, and is sufficiently released by play in the radial bearing and the thrust bearing.

In this type of disc / roller type continuously variable transmission, force transmission between the disc and the roller is performed by frictional contact between the smooth curved surfaces of the two, so that a large amount of power required for driving the vehicle is generated. In order to transmit, the disk and roller must be pressed together with a very strong force. The opposing roller pressing surfaces of a pair of discs are generally toroidal surfaces with a medium and high height in the shape of Mt.Fuji, so when a pair of discs are pressed against each other with a strong force across the rollers, As shown by the arrow F in FIG. 3, a large force acts radially outward from the center of the disk. These forces F are received by the V-shaped links 20, 22, and 28, and the leg portions 20a, 20c, 22a, 22b, 28b, and 28c are directed from the pivot portions by the respective pivot shafts 40a, 40b, and 40c toward the leg ends. The direction force f (= F / 2) acts, and the legs 20a and 20c, 22a and 22b, and 28b and 28c are V-shaped, respectively, so that the pivots 40a, 40b, and 40c are connected to the center 10C of the disk. A force of 2 f cos 60 ^o (= f) acting outward in the radial direction acts.

  Since the force F is very strong as described above, the force f, which is a half of the force F, is still strong. Conventionally, the pivots 40a, 40b, and 40c are supported by three types of links such as the trifurcated link 38. Means are used to cancel the force f between them so that the force f does not act directly on the housing 44. However, such a trifurcated link requires a fairly robust structure and is a costly member, and the space in which such a trifurcated link is provided is the upper limit of the structure of the disk / roller type continuously variable transmission. The need for the arrangement of a three-way link having a robust structure in this space greatly limits the degree of freedom in designing this type of disk / roller type continuously variable transmission.

  The present invention pays attention to the above situation, and an object of the present invention is to improve this type of disk / roller type continuously variable transmission so that the three-way link can be omitted or reduced in weight.

  In order to solve the above-described problems, the present invention provides a pair of disks each having an operating surface whose radius changes along an axis, and the operating surfaces of the pair of disks are coaxially opposed to each other. And at least three rollers carried by the trunnion, and a rotational force is transmitted between the pair of disks via each of the rollers. At this time, the center axis of each roller is in relation to the center axis of the pair of disks. The disc / roller type continuously variable transmission is configured to change the speed ratio of the rotational force transmitted between the pair of disks by causing the rollers to tilt with respect to the pair of disks by being displaced. The ends of the trunnions adjacent to each other are connected to each leg of a V-shaped link pivotally supported at the base where two legs meet by a radial / thrust bearing, The rollers are allowed to tilt with respect to the disk, and when the rollers are pressed between the pair of disks, the outward force in the disk radial direction acting on the rollers causes the trunnion and the V-shaped link to be alternately connected. The present invention proposes a disc / roller type continuously variable transmission which is supported by a ring.

  The base part of the V-shaped link may be pivotally supported by the housing of the continuously variable transmission.

  The actuator may be provided only for selected ones of the trunnions.

  As described above, a pair of discs having an operating surface whose radius changes along the axis, and at least three discs sandwiched between the operating surfaces of the pair of discs coaxially opposed to each other and supported by trunnions And a rotational force is transmitted between the pair of discs via the rollers, and the center axis of each roller is displaced with respect to the center axis of the pair of discs. In a disc / roller type continuously variable transmission which is tilted with respect to the pair of discs to change a gear ratio of a rotational force transmitted between the pair of discs, adjacent ends of the trunnion Tilts of the rollers with respect to the pair of disks are connected to each leg part of the V-shaped link pivotally supported at the base part where the two leg parts meet by a radial / thrust bearing. Allowing each of the rollers to be held between the pair of disks so that the outward force in the radial direction of the disk acting on the rollers is supported by the ring formed by alternately connecting the trunnion and the V-shaped link. If a pair of discs are pressed against each other with a strong force with a roller sandwiched between them, a force directed radially outward from the center of the disc acting on the rollers is applied to both legs of the V-shaped link. A means that can be supported without depending on the pivot at the root portion, and that counteracts the force radially outward from the center of the disk acting on each roller, such as the above-mentioned trifurcated link, between them. Omitted or reduced in weight. In this case, the pivotal support at the base of both legs of the V-shaped link is required to guide the movement of the ring that is slightly rotated by the alternate connection of the trunnion and the V-shaped link when changing the gear ratio. It can be a light pivot.

  As a matter of course, as described above, the ends of the trunnion adjacent to each other are connected to each leg of the V-shaped link pivotally supported at the root where the two legs intersect with each other by a radial / thrust bearing. The structure in which the outward force in the radial direction of the disk acting on the roller by being pressed between a pair of disks is supported by the ring by alternately connecting the trunnion and the V-shaped link is a V-shaped structure rather than a trunnion as seen in FIG. The thrust bearing can support the above-mentioned resultant force f acting on the link base, and the thrust bearing at the connecting portion between the end of the trunnion and the leg of the V-shaped link is shown in FIG. Unlike thrust bearings 50, 52, 54, 56, 68, 60, these thrust bearings are thrust bearings provided on the opposite side to the leg of the V-shaped link. It means.

  Therefore, the pivoting of such a light V-shaped link is also permitted by pivoting the root of the V-shaped link only with the housing of the continuously variable transmission.

  Further, as described above, adjacent ends of the trunnion are connected to each leg portion of the V-shaped link pivotally supported at the base portion where the two leg portions intersect with each other by a radial / thrust bearing, and each roller is connected between a pair of disks. In the structure in which the outward force in the disk radial direction acting on the roller by being held between the trunnion and the V-link is alternately supported by the ring, the ring operates the continuously variable transmission. Because it is always urged in the expanding direction, the play of the radial / thrust bearing is all biased in a certain direction, and the shape of the entire ring is highly stable, so the gear ratio of the continuously variable transmission When changing, a force or displacement for displacing the center axis of each of the three or more rollers with respect to the disk center axis can be applied to all the rollers if applied to one location of the above ring. And it exerted evenly. Therefore, in this case, the actuators for roller bias such as the actuators 46a, 46b, 46c in FIG. 3 do not necessarily have to be provided for all trunnions, only for the selected trunnions. In other words, the continuously variable transmission can be operated without any trouble by providing it for all trunnions or less than all trunnions.

  FIG. 1 is an exploded sectional view showing an embodiment in which a disk / roller type continuously variable transmission according to the present invention is implemented as a three-roller disk / roller type continuously variable transmission. The cross section shown in the figure is also perpendicular to the central axis of a pair of discs whose working surfaces are coaxially opposed, as in FIG. 3 which schematically shows the basic structure of a conventional three-roller disc / roller type continuously variable transmission. This is due to the cross section. In order to avoid duplicating the description of the same structure, the same reference numerals as those in FIG. 3 are assigned to the portions corresponding to the portions described in FIG. The overlapping description of the parts to be omitted is omitted unless particularly necessary.

  In the disk / roller type continuously variable transmission according to the present invention shown in FIG. 1, the thrust bearings at the connecting portions between the trunnions 14a, 14b, 14c and the leg portions of the V-shaped links 20, 22, 28 are: Thrust bearings 64, 66, 68, 70, 72, 74 that come into contact with the leg portions 20 a, 20 c, 22 a, 22 b, 28 b, 28 c of the V-shaped link from the side opposite to the side where the trunnion roller bearing portion is located. The leg portion of the V-shaped link is restricted from moving in the direction away from the trunnion roller bearing portion with respect to the trunnion at the connecting portion between each leg portion of the V-shaped link and the trunnion. The ring is held against the force acting on the V-shaped link described with reference to FIG. 3 so that the ring due to the alternate connection of the links does not expand. In the structure of FIG. Ri force has been canceled is canceled by the action tension other of said rings.

  In this case, the pivots 40a, 40b, and 40c that pivotally support the V-shaped links 20, 22, and 28 maintain the position of the ring by the alternate connection of the trunnion and the V-shaped link as a whole, and change the gear ratio. When the trunnions 14a, 14b, and 14c move in accordance with the operation of the actuators 46a, 46b, and 46c so that the central axes 48a, 48b, and 48c of the respective rollers 12a, 12b, and 12c are biased with respect to the disk central axis 10c, Since it is only necessary to provide support for stably rotating the V-shaped links 20, 22, and 28 around their pivot points, no force is exerted on the pivots 40 a, 40 b, 40 c, and these are the rib portions. It may be supported directly from the housing 44 by means such as 76, 78, 80, 82. In the illustrated embodiment, the conventional trifurcated link 38 described with reference to FIG. 3 is completely eliminated, but the conventional trifurcated link is left in a reduced form, thereby The pivots 40a, 40b, and 40c may be supported. In short, an annular body formed by alternately connecting the trunnions 14a, 14b, 14c and the V-shaped links 20, 22, 28 can carry the force acting in the expanding direction by the thrust bearing acting between the trunnion and the V-shaped link. It is whether or not.

  FIG. 2 shows that the ring formed by alternately connecting the trunnion and the V-shaped link is constrained by the thrust bearings 64, 66, 68, 70, 72, 74, and the V-shaped links 20, 22, 28 described with reference to FIG. Is constantly urged in the expanding direction during operation of the continuously variable transmission, and the radial bearings 24, 26, 30, 32, 34, 36 and the thrust bearings 64, 66, 68, 70, 72, 74 are urged. In view of the fact that all of the play is shifted in a certain direction and the shape of the entire ring is highly stable, each of the three rollers 12a, 12b, 12c In order to uniformly bias the central axes 48a, 48b, and 48c of the disk with respect to the disk central axis 10C, the actuator 46a for the three trunnions 14a, 14b, and 14c is not necessarily required. Even if all of 46b and 46c are not operated, if a displacement is applied to one position of the above-mentioned ring by the operation of any one of these actuators, it is equally applied to all the rollers. 1 is a view similar to FIG. 1 showing an embodiment in which only the actuator 46c is provided and 46a and 46b are eliminated. In FIG. 2, the same reference numerals as in FIG. 1 are assigned to the portions corresponding to the portions shown in FIG. Obviously, the omission of the actuator may be arbitrarily selected from 46a, 46b and 46c, and only one omission may be made.

  While the present invention has been described in detail with reference to two embodiments, it will be apparent to those skilled in the art that various modifications can be made to these embodiments within the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded sectional view showing an embodiment in which a disc / roller type continuously variable transmission according to the present invention is implemented as a three-roller disc / roller type continuously variable transmission. FIG. 3 is a similar exploded sectional view showing another embodiment in which a part of the embodiment shown in FIG. 1 is changed. The figure which shows in figure the basic structure of the conventional 3 roller type disc / roller type continuously variable transmission.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Disk, 12a, 12b, 12c ... Roller, 14a, 14b, 14c ... Trunnion, 16a, 16b, 16c ... Radial / thrust bearing, 18a, 18b, 18c ... Eccentric shaft, 20 ... V type link, 20a, 20c ... Legs of the V-shaped link 20, 22 ... V-shaped links, 22a, 22b ... legs of the V-shaped link 22, 24, 26 ... radial bearings, 28 ... V-shaped links, 28b, 28c ... legs of the V-shaped link 28 , 30, 32, 34, 36 ... radial bearings, 38 ... trifurcated links, 38a, 38b, 38c ... legs of the trifurcated links, 38d ... annular portions of the trifurcated links, 40a, 40b, 40c ... pivots 42a, 42b, 42c ... pin, 44 ... housing, 46a, 46b, 46c ... hydraulic actuator, 48a, 48b, 48c ... roller central axis, 50,52,5 , 56, 58, 60 ... thrust bearings, 62af, 62ar, 62bf, 62br, 62cf, 62cr ... shoulders of trunnions, 64, 66, 68, 70, 72, 74 ... thrust bearings, 76, 78, 80, 82 ... Rib part

Claims (3)

  A pair of discs having operating surfaces whose radii change along the axis, and at least three rollers which are sandwiched between the operating surfaces of the pair of discs and are carried by trunnions. Then, a rotational force is transmitted between the pair of disks via the rollers, and the center axis of each roller is displaced with respect to the center axis of the pair of disks. The disc / roller type continuously variable transmission device is configured to change the gear ratio of the rotational force transmitted between the pair of discs by tilting with respect to the two discs. The base part where the parts intersect is connected to each leg part of the V-link pivotally supported by a radial / thrust bearing, and the tilting of each of the rollers with respect to the pair of disks is allowed. Both of the rollers are supported by a ring formed by alternately connecting the trunnion and the V-shaped link so that the outward force in the disk radial direction acting on the roller is pressed between the pair of disks. Disc / roller type continuously variable transmission.   2. The disk / roller type continuously variable transmission according to claim 1, wherein a root portion of the V-shaped link is pivotally supported by a housing of the continuously variable transmission. 3. The disk / roller type continuously variable transmission according to claim 1, wherein the actuator is provided only for a selected one of the trunnions.

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