JP2017031994A - Continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve power transmission efficiency, in a continuously variable transmission.SOLUTION: A continuously variable transmission is equipped with a first ball 20 and a second ball 30 which are tiltably provided between an input shaft 10 and a sub shaft 14; a first disc 40 and a second disc 42 which have friction surfaces capable of transmitting power between the input shaft 10, and the first ball 20 and the second ball 30; and a third disc 44 and a fourth disc 46 which have friction surfaces capable of transmitting power between the sub shaft 14, and the first ball 20 and the second ball 30. Thrust which the first ball 20 and the third ball 30 receive from the first to the fourth discs 40, 42, 44, and 46 is cancelled at a contact E between the first ball 20 and the second ball 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a continuously variable transmission (CVT) used in an automobile driven by an engine.

  Conventionally, this type of continuously variable transmission includes a power roller that is in contact with a curved surface formed in a toroidal shape between an input disk and an output disk that are arranged to face each other, and the power roller is supported by a trunnion and tilts. There is known one that obtains a stepless speed ratio (speed ratio) (see, for example, Patent Document 1).

However, the toroidal curved surface formed on the input disk and the output disk in the toroidal-type continuously variable transmission provided with the power roller in contact with the curved surface formed in the toroidal shape of the input disk and the output disk arranged opposite to each other. It is also related to the fact that a power roller is installed on the outside in the radial direction and the same outer surface on the inside in the radial direction of the power roller is in contact with both the input disk and the output disk to transmit power, so that a large thrust acts on the transmission of these power There were the following problems.
That is, since the input disk and the output disk rotate in opposite directions, the bearing loss that receives the thrust acting between the two is large, and the power transmission efficiency is lowered accordingly.
Furthermore, the bearing loss that supports the radial thrust acting on the power roller is large, and the power transmission efficiency is reduced.

JP 2013-213563 A

The problem to be solved is that the bearing loss between the input shaft and the output shaft, which receives each thrust of the input disc, the output disc and the power roller, is combined with the rotation of the input shaft and the output shaft in opposite directions. It is large and the power transmission efficiency is low.
The purpose of the present invention is to make the input shaft and the output shaft rotate in the same direction and not to receive the thrust acting on the power roller by the roller support bearing, thereby greatly reducing the rotation loss of each support bearing. There is to make it.

  A continuously variable transmission according to the present invention includes an input shaft, an output shaft, a sub shaft arranged in parallel with the input shaft and the output shaft, a case, a stator that can be locked to the case, and an input shaft and a sub shaft. A first ball shaft and a second ball shaft, which are disposed between the pair and are provided to be tiltable on the stator, are rotatably supported by the first ball shaft and the second ball shaft, respectively, and directly or through a bearing or the like. Two first balls and second balls that are in contact with each other at the contact points, a first disk having a friction surface capable of transmitting power in contact with the first ball, the rotation direction being integrated with the input shaft or the output shaft, and the second disk A second disk having a friction surface capable of power transmission in contact with the ball; a third disk having a friction surface capable of power transmission in contact with the first ball; And a friction surface capable of transmitting power. A thrust that acts on the first ball and the second ball from the first disk and the second disk, and a thrust that acts on the first ball and the second ball from the third disk and the fourth disk. It is characterized in that it is canceled out at the contact point between the first ball and the second ball.

  The continuously variable transmission according to the present invention rotates when the first ball and the second ball are in contact with each other, and the first ball is moved continuously between the input shaft and the auxiliary shaft via the first to fourth disks. The thrust that the second ball receives from the first to fourth disks cancels out at the contact point between the first ball and the second ball.

Therefore, in the continuously variable transmission of the present invention, the input shaft and the output shaft rotate in the same direction, and the thrust acting on the two balls corresponding to the power roller of the conventional example cancels each other. Loss of the bearing that supports the ball is reduced, and power transmission efficiency can be improved.

FIG. 3 shows a main part of the continuously variable transmission according to the first embodiment of the present invention, and is a cross-sectional view taken along line AA in FIG. 2. Example 1 It is sectional drawing along the BB line in FIG. It is sectional drawing which shows the operation state in the continuously variable transmission of FIG. FIG. 6 is a cross-sectional view showing another operating state of the continuously variable transmission of FIG. 1. FIG. 7 is a cross-sectional view taken along the line CC of FIG. 6, illustrating a main part of the continuously variable transmission according to the second embodiment of the present invention. It is sectional drawing along the DD line in FIG. It is the skeleton figure which showed the continuously variable transmission of Example 3 of this invention. It is the skeleton figure which showed the continuously variable transmission of Example 4 of this invention.

  Hereinafter, a continuously variable transmission according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a main part of a continuously variable transmission according to Embodiment 1 of the present invention, and is a cross-sectional view taken along line AA of FIG. FIG. 2 is a cross-sectional view taken along line BB in FIG. 1 excluding the case 3 described later. In both figures, the upper half of the center line of the input shaft 10 and the output shaft 12 described later is drawn.
3 and 4 are operation diagrams showing a state in which a speed ratio described later is changed from the state of FIG.

The input shaft 10 and the output shaft 12 that are rotatably supported by the first plate 4 and the second plate 5 that are integral with the case 3 are the same center of rotation.
In the following description, unless otherwise specified, the expressions “axial direction” and “radial direction” are intended for the input shaft 10.
Four sub-shafts 14 are arranged in parallel with the input shaft 10 and the output shaft 12 at equidistant positions on the pitch circle centered on the input shaft 10 and the output shaft 12, and both end portions thereof are the first plate 4. The second plate 5 is rotatably supported by bearings 4a and 5a.

Between the input shaft 10 and each sub-shaft 14, the 1st ball | bowl 20 and the 2nd ball | bowl 30 are arrange | positioned along with the axial direction, respectively, and these balls | bowls 20 and 30 are in contact with the contact E. The first ball 20 and the second ball 30 are rotatably supported on the first ball shaft 22 and the second ball shaft 32 by bearings 22a and 32a, respectively.
Referring to FIG. 2, the first ball shaft 22 and the second ball shaft 32 are fixed to the first trunnion 24 and the second trunnion 34, respectively.
The first ball 20 and the second ball 30 have a gap that can move slightly in the axial direction of the first ball shaft 22 and the second ball shaft 32 with respect to the first trunnion 24 and the second trunnion 34. have.

As shown in FIGS. 1 and 2, the first trunnion 24 and the second trunnion 34 are supported by the first holder 26 and the second holder 36 so as to be tiltable by pins 26a and 36a, respectively.
The first holder 26 and the second holder 36 are supported by the first stator 28 and the second stator 38 so as to be swingable by pins 28a and 38a (indicated by a two-dot chain line in FIG. 1).
Since the pins 26a, 36a and the pins 28a, 38a are slightly separated from each other, the first ball 20 and the second ball 30 move in the axial direction when the first holder 26 and the second holder 36 are swung. Is possible.
Although the detailed illustration is omitted, the first stator 28 and the second stator 38 are respectively engaged with the first plate 4 and the second plate 5, and as described later, a little (predetermined predetermined) about the input shaft 10 (Rotation range) It can be rotated.
2 is a cross section on the first ball 20 side, the cross section on the second ball 30 side is the same as this. Accordingly, the pin 38a corresponds to the pin 28a.

A guide sleeve 16 is provided between the input shaft 10 and each of the first balls 20 and the second balls 30, and the guide sleeve 16 is formed with four first guide grooves 16a and four second guide grooves 16b. The first and second guide grooves 16a and 16b are engaged with end portions 22b and 32b on the input shaft 10 side of the first ball shaft 22 and the second ball shaft 32, respectively. The end portions 22b and 32b are partially formed into a spherical shape.
The first and second guide grooves 16a and 16b are helical grooves. As shown in FIGS. 3 and 4, the first ball shaft 22 and the second ball shaft 32 are tilted and the guide sleeve 16 is tilted. Rotates about the input shaft 10.

A first disk 40 is provided on the input shaft 10 via a ball spline 10a so that the rotation direction is integral and the axial direction is movable, and the second disk 42 is provided integrally by a spline 10b and a snap ring 10c.
The first disk 40 and the second disk 42 are respectively in contact with the outer surfaces 20a and 30a of the first ball 20 and the second ball 30 to form friction surfaces 40a and 42a capable of transmitting torque.

  The input shaft 10 is provided with a cylinder 10d and a piston 10e. A hydraulic pressure, which will be described later, is applied to the piston 10e to press the first disk 40 against the first ball 20, and at the same time, the second through the snap ring 10f. A so-called thrust that draws the disk 42 toward the second ball 30 can be applied.

On the other hand, a third disk 44 and a fourth disk 46 are integrally provided on the countershaft 14, and, like the first disk 40 and the second disk 42, the outer surfaces 20 a of the first ball 20 and the second ball 30, respectively. , 30a, and friction surfaces 44a and 46a capable of transmitting torque are formed.
Therefore, when a thrust is applied to the first disk 40 by the piston 10e, the first disk 40 and the second disk 42 sandwich the two first balls 20 and the second ball 30 in the axial direction. The friction surfaces 40 a and 42 a are pressed against the outer surfaces 20 a and 30 a of the first ball 20 and the second ball 30.

  Here, since the first ball 20 and the second ball 30 can move slightly in the axial direction of the first ball shaft 22 and the second ball shaft 32 as described above, the first ball 20 and the second ball 30 can be moved from the first disk 40 and the second disk 42. The thrust received by the first ball 20 and the second ball 30 causes the first ball 20 and the second ball 30 to move radially outward and be pressed against the third disk 44 and the fourth disk 46.

  That is, the thrust generated by the piston 10e is the friction surfaces 40a, 42a, 44a, 46a of the four first to fourth disks 40, 42, 44, 46, and the two first balls 20 and the second balls 30. The outer surfaces 20a and 30a of each other are pressed against each other, and the thrust acts on the contact point E between the first ball 20 and the second ball 30 to be offset.

  The four countershafts 14 respectively form a first outer surface 14a and a second outer surface 14b, and a first support ring 50 and a second support ring 52 that surround and contact the first outer surface 14a and the second outer surface 14b. Is provided. That is, the inner surface 50a of the first support ring 50 and the inner surface 52a of the second support ring 52 are in contact with the first outer surface 14a and the second outer surface 14b of the four countershafts 14, respectively. A cylindrical spacer 50 b is inserted between the first support ring 50 and the second support ring 52.

As described above, the thrust acting on the first ball 20 and the second ball 30 from the four friction surfaces 40a, 42a, 44a, and 46a is offset by the contact point E, but the four first surfaces are accompanied by the thrust. The radial force acting on the fourth discs 40, 42, 44, and 46 is as follows.
That is, since the first and second disks 40 and 42 are in contact with the four first balls 20 and the second balls 30 disposed around the first and second disks 40 and 42, respectively, the radial force due to the thrust is They cancel each other out.

On the other hand, since the third and fourth disks 44 and 46 receive radial force from the first ball 20 and the second ball 30 respectively, their radial loads are applied to the first through the bearings 4a and 5a. It acts on the plate 4 and the second plate 5.
However, since the first support ring 50 and the second support ring 52 in contact with the four countershafts 14 are provided, the diameters of the third and fourth disks 44 and 46 received from the first ball 20 and the second ball 30 by them. Can handle loads in the direction.
That is, since the first support ring 50 and the second support ring 52 receive a part or most of the radial load received from the four countershafts 14, this can be offset.

  A driving gear 46 b is integrated with the fourth disk 46, and meshes with the driven gear 12 a integrated with the output shaft 12. That is, the driven gear 12 a is driven from the four countershafts 14.

Next, the operation of the continuously variable transmission of the first embodiment shown in FIGS. 1 and 2 will be described with reference to FIGS.
Although not shown, the continuously variable transmission shown in FIG. 1 can include a hydraulic pump and a controller, and the following operations may be performed based on instructions from the controller. In addition, the continuously variable transmission of the first embodiment uses an appropriate hydraulic oil that also serves as a lubricant.
The rotation direction in the following description indicates a case where it is viewed from the left side in FIG.

  When the input shaft 10 rotates and a hydraulic pressure corresponding to the torque is supplied to the cylinder 10d, the piston 10e pushes the first disk 40 toward the first ball 20 and pulls the second disk 42 toward the second ball 30. As described above, the contact surfaces of the four third and fourth disks 44 and 46 are also combined, and the friction surfaces 40a, 42a, 44a, and 46a, and the outer surfaces of the two first balls 20 and the second balls 30 are combined. 20a and 30a are pressed against each other.

Thus, when the input shaft 10 is rotated clockwise, the first disk 40 rotates the first ball 20 clockwise, and the second disk 42 rotates the second ball 30 counterclockwise.
The first and second balls 20 and 30 rotate the countershaft 14 counterclockwise via the third and fourth disks 44 and 46. Although not involved in power transmission, the first and second support rings 50 and 52 rotate counterclockwise.

Here, as shown in FIGS. 3 and 4, the contact point between the first disk 40 and the first ball 20 is F, the contact point between the second disk 42 and the second ball 30 is G, and the third disk 44 and the first ball 20. , And the contact point between the fourth disk 46 and the second ball 30 is I. Strictly speaking, it is difficult to specify the position of each contact point. However, as shown in the drawing, the vicinity of the center of each contact portion will be described as a contact point.
The distance between the contact F and the center of the input shaft 10 is R1, the distance between the contact F and the center of the first ball shaft 22 is R2, the distance between the contact G and the center of the first ball shaft 22 is R3, and the contact G. Is defined as R4. Note that the contacts H and I are regarded as symmetrical with the contacts F and G with the contact E between the first and second balls 20 and 30 as the center, and the description thereof is omitted.

  As a result, the rotational speed ratio between the input shaft 10 and the auxiliary shaft 14 (the speed of the input shaft 10 / the speed of the auxiliary shaft 14) can be defined as R2 / R4 / R1 / R3 if there is no slip at each contact. . Further, the rotational speed of the output shaft 12 can be calculated by adding the gear ratio of the drive gear 46b and the driven gear 12a to this. The rotation direction of the output shaft 12 is the same as that of the input shaft 10.

Next, a case where the rotational speed ratio between the input shaft 10 and the auxiliary shaft 14 is changed will be described.
In FIG. 1, the first and second ball shafts 22 and 32 are perpendicular to the input shaft 10 and the auxiliary shaft 14, and the first ball shaft 22 and the second ball shaft 32 are parallel to each other, and the distance R2 And R3 can be said to have the same value, and the speed ratio in this case is approximately the center value of the speed ratio range described later.
Subsequently, as shown in FIG. 3, when the first ball shaft 22 is tilted counterclockwise and the second ball shaft 32 is tilted in the opposite direction, the above-mentioned distances R3 and R2 change from FIG. R3 is smaller than R2. Similarly, the distances R3 and R4 change, but the description is omitted. As a result, in the state of FIG. 3, it changes to the deceleration side compared with FIG.
At this time, it can be seen that the guide sleeve 16 rotates from the position shown in FIG.

Next, FIG. 4 shows the case where the first ball shaft 22 is tilted clockwise and the second ball shaft 32 is tilted counterclockwise, contrary to FIG. As apparent from FIG. 4, since the distance R3 is larger than the distance R2, the state in FIG. 4 is on the speed increasing side as compared with FIG.
Also at this time, it can be seen that the guide sleeve 16 is rotating from the position shown in FIGS.
In this manner, the first ball shaft 22 and the second ball shaft 32 are tilted symmetrically about the contact point E with the center in FIG. 1, so that the speed ratio is not changed from the state in FIG. 3 to the state in FIG. Can be changed in stages.

Next, a method for changing the tilt angles of the first ball shaft 22 and the second ball shaft 32 will be described.
As described above, the tilt angle between the first ball shaft 22 and the second ball shaft 32 changes, and the guide sleeve 16 rotates. Therefore, it is possible to change the tilt angles of the first ball shaft 22 and the second ball shaft 32 by rotating the guide sleeve 16, and it can be said to be an effective means particularly when the transmission torque is small.

However, when the transmission torque is large, the tilt angle between the first ball shaft 22 and the second ball shaft 32 is changed by the following method.
As can be seen from FIG. 2, in a steady state in which a constant speed ratio is maintained, a line connecting the center of the input shaft 10 and the center of the auxiliary shaft 14 and the center lines of the first ball shaft 22 and the second ball shaft 32 are one. However, it is possible to change the tilt angle of the first ball shaft 22 and the second ball shaft 32 by changing this.

That is, the first and second stators 28 and 38 that substantially support the first ball shaft 22 and the second ball shaft 32 described above are slightly rotated around the input shaft 10. The following description will be made on the first ball 20 side. As a result, the positional relationship between the center line of the first ball shaft 22 and the contacts F and G as seen in FIG. As a result, a couple force that tilts the first ball shaft 22 acts on the contacts F and G to tilt them. When the desired speed ratio is reached, the first stator 28 is returned to the position shown in FIG. As a result, a steady state is obtained in which the speed ratio is changed.
The same thing also works on the second ball 30 side that is symmetrically arranged.
At this time, the guide sleeve 16 has a function of regulating the tilt angles of the total eight ball shafts 22 and 32 so as not to deviate from each other.

The method of rotating the first and second stators 28 and 38 is one means, and as another method, for example, the first ball shaft 22 and the second ball shaft 32 are translated in the left and right directions in FIG. You may make it move close to it.
Although the method for rotating the first and second stators 28 and 38 is not shown, it may be moved by hydraulic pressure or by an electric motor.

  Thus, according to the first embodiment, the thrust that presses the friction surfaces 40a, 42a, 44a, 46a and the outer surfaces 20a, 30a of the two first balls 20 and the second balls 30 for power transmission is as follows. Since they cancel each other at the contact point E between the first ball 20 and the second ball 30, they do not act on the bearings 22a and 32a, and no loss associated with thrust occurs in the bearings 22a and 32a.

On the other hand, the radial force generated at each of the contacts F, G, H, and I cancels each other because the input shaft 10 acts from the four directions of the auxiliary shafts 14.
About each countershaft 14, since the 1st and 2nd support rings 50 and 52 can receive the load of the radial direction received from the 3rd disk 40 and the 4th disk 42, the load which acts on bearing 4a, 5a is greatly increased. Can be reduced.

That is, although the center-to-center distance between the input shaft 10 and the sub shaft 14 depends on the dimensional accuracy, rigidity, thermal expansion, and the like of related members, the first and second outer surfaces 14a and 14b of the sub shaft 14 and the first The inner diameters of the second support rings 50 and 52 are suitable for receiving the radial loads received from the third disk 40 and the fourth disk 42 because the dimensional accuracy is easily secured.
Further, by making the first plate 4 and the second plate 5 with a material having a large thermal expansion coefficient, the load acting on the bearings 4a and 5a is reduced particularly when the temperature is increased, and the first and second support rings 50 are reduced. , 52 can be increased and the loss of the bearings 4a and 5a can be reduced.

In addition, since the rotation directions of the input shaft 10 and the output shaft 12 are the same, and there is no bearing on which thrust acts, there is no loss even on this surface.
Therefore, it is possible to greatly reduce the rotational loss of the bearings at each part due to the thrust accompanying the power transmission, and improve the power transmission efficiency over the conventional example.
Further, since the thrust due to the thrust does not act on the first and second trunnions 24 and 34 and the first and second holders 26 and 36 at all, it is not necessary to make them ruggedly and make them lightweight and at low cost. It is also a merit to be able to.

Next, a continuously variable transmission according to Embodiment 2 of the present invention will be described.
5 is a cross-sectional view of the continuously variable transmission according to the second embodiment, taken along the line CC of FIG. 6, corresponding to FIG. 1. FIG. 6 is a cross-sectional view taken along the line DD of FIG. FIG.
However, in FIG. 5, the cylinder 10d and the piston 10e are not shown, but are the same as those described in the first embodiment.
Here, the description will focus on parts that are different from the first embodiment, and parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

The first difference between the second embodiment and the first embodiment is that the second disk 42 is integrated with the output shaft 12 in the rotation direction and integrated with the input shaft 10 only in the axial direction.
That is, a thrust bearing 10f is provided between the input shaft 10 and the second disk 42, and the second disk 42 is moved through the input shaft 10 by the action of the cylinder 10d and the piston 10e (not shown) as in the first embodiment. 2 pressed against the ball 30.
The second disk 42 is connected to the output shaft 12 by meshing the dog teeth 42b and 12b.

Accordingly, the first CVT 1 extending from the input shaft 10 and the first disk 40 to the auxiliary shaft 14 via the first ball 20 and the third disk 44, and the second ball 30 and the second disk 42 from the auxiliary shaft 14 and the fourth disk 46. The second CVT 2 reaching the output shaft 12 via the two-stage continuously variable transmission in series is performed. The first ball 20 and the second ball 30 are different in size.
In relation to these, the first ball 20 and the second ball 30 have a tilt direction and a rotational speed different from those of the first embodiment, and therefore a second thrust bearing 58 is provided between them. Further, there is no gear between the auxiliary shaft 14 and the output shaft 12.

  The second difference is that there are six sub-shafts 14, and accordingly, the first and second balls 20, 30, etc. are also in six pairs.

The third difference is around the first and second ball axes 22 and 32.
The trunnion in the first embodiment is omitted, and the first and second ball shafts 22 and 32 are directly supported by the first and second stators 28 and 38. That is, the first and second ball shafts 22 and 32 are respectively provided with two first rollers 22c and second rollers 32c. The first and second rollers 22c and 32c are engaged with grooves 28b and 38b formed in the first stator 28 and the second stator 38, respectively, so that the first and second ball shafts 22 and 32 are tilted. Along with this, the grooves 28b and 38b roll.
The first and second guide grooves 16a and 16b of the guide sleeve 16 are simply circumferential grooves, and the guide sleeve 16 moves in the axial direction as the first and second ball shafts 22 and 32 are tilted. To do.
Therefore, the first ball shaft 22 and the second ball shaft 32 are tilted while maintaining substantially parallel.

The fourth difference is around the countershaft 14.
Similarly to the first embodiment, the six countershafts 14 form a first outer surface 14a and a second outer surface 14b, respectively, and the support ring 50 that surrounds and contacts the first outer surface 14a and the second outer surface 14b is one. It has a cylindrical shape with flanges 50c and 50d at both ends.
The third disk 44 and the fourth disk 46 are respectively formed with conical surfaces 44c, 46c on the opposite sides in the axial direction of the friction surfaces 44a, 46a, and a conical inner surface 54a in contact with the conical surface 44c. And a third support ring 56 having a conical inner surface 56a in contact with the conical surface 46c.
The third support ring 54 and the third support ring 56 are connected.

Accordingly, the bearing 4a and the bearing 5a are respectively held by the bearing holder 6, and the bearing holder 6 is swingably attached to the case 3 via the pin 6a. Therefore, the auxiliary shaft 14 can move (swing) in the radial direction.
The third disk 44 is connected to the auxiliary shaft 14 and the ball spline 14c so as to be movable in the axial direction.

  The fifth difference is that the first and second stators 28 and 38 have a first control shaft 28c and a second control shaft 38c for rotating the first and second stators 28 and 38, respectively. That is, in the case of the first control shaft 28c, as shown in FIG. 6, the first control shaft 28c has an eccentric portion 28d of the eccentric shaft center K in addition to the rotation center J, and the first stator 28 has a long length. A hole 28e is formed.

Therefore, when the control arm 28f (see FIG. 5) integrated with the first control shaft 28c is operated to rotate the first control shaft 28c, the first stator 28 is slightly moved by the action of the eccentric portion 28d and the long hole 28e. Rotate to. The same applies to the second stator 38 and the second control shaft 38c, and the first stator 28 and the second stator 38 can operate independently of each other.
The second control shaft 38c of the second stator 38 is engaged with the second stator 38 through the hole 28g of the first stator.
The control arm 28f is operated by an actuator (not shown).

Next, the operation of the continuously variable transmission according to the second embodiment shown in FIGS. 5 and 6 will be described.
As described in the first embodiment, the contact points of the first to fourth disks 40, 42, 44, 46 and the first and second balls 20, 30 are F, G, H, and I, respectively. The distances between the contact points and the center lines of the input shaft 10, the auxiliary shaft 14, the first and second ball shafts 22 and 32 are R1 to R8 as shown in FIG.

In the same manner as in the first embodiment, the first disk 40 and the second disk 42 are pressed against each other so as to sandwich the first and second balls 20 and 30 in the same manner as in the first embodiment. 46 is also pressed against the first and second balls 20 and 30.
As a result, the torque of the input shaft 10 drives the auxiliary shaft 14 via the first disk 40, the first ball 20, and the third disk 44, and further via the fourth disk 46, the second ball 30, and the second disk 42. To drive the output shaft 12.

As a result, the speed ratio (speed of the input shaft 10 / speed of the output shaft 12) is (R2, R4, R6, R8) / (R1, R3, R5, R7), of which the first and second balls It is R2, R3, R6, and R7 that change due to the tilting of the shafts 22 and 32.
These continuously variable transmissions are controlled by rotating the first stator 28 and the second stator 38 as in the description of the first embodiment. Therefore, as described above, the first control shaft 28c and the second control shaft 38c are rotated.
Here, the difference from the first embodiment is that the first ball shaft 22 and the second ball shaft 32 are tilted while being substantially parallel. Therefore, the rotation directions of the first stator 28 and the second stator 38 are reversed. It is necessary to control both of them independently.
Further, as described above, the first ball shaft 22 and the second ball shaft 32 tilt with the axial movement of the guide sleeve 16.
The support ring 50, the third support ring 54, and the third support ring 56 do not participate in power transmission but rotate in reverse.

Next, the thrust associated with power transmission is as follows.
In the first thrust bearing 10g between the input shaft 10 and the second disk 42, since the input shaft 10 and the second disk 42 rotate in the same direction, for example, when the speed ratio is 1, there is a speed difference. The bearing loss is significantly reduced as compared with the conventional example in which the rotations are reversed to each other so as to be 0 (zero).
The thrust acts on a second thrust bearing 58 that is a contact point between the first ball 20 and the second ball 30. Here, unlike Example 1, there is a slight speed difference between the two, so a loss occurs according to the speed ratio. Again, the speed difference may be zero, and no loss occurs in that state.

Subsequently, with respect to the radial load accompanying the thrust, the load from the six pairs of first and second balls 20 and 30 cancels out in the input shaft 10 as in the first embodiment.
Further, in the auxiliary shaft 14, since the bearings 4a and 5a are supported by the bearing holder 6 so as to be swingable as described above, no radial load is applied. Accordingly, loads from the first and second balls 20 and 30 act on both the support ring 50, the third support ring 54, and the fourth support ring 56. The sharing ratio between the support ring 50 and the third and fourth support rings 54 and 56 varies depending on the setting of the angles of the conical surfaces 44c and 46c of the second disk 42 and the third disk 44.

  That is, as the conical surfaces 44c and 46c are brought closer to the plane, the load on the fourth support rings 54 and 56 is reduced, and the load on the support ring 50 is increased. Therefore, the angles of the conical surfaces 44c and 46c are set in consideration of the rigidity of the support ring 50 and the third and fourth support rings 54 and 56.

In the second embodiment, as described above, the first step continuously variable transmission is performed between the input shaft 10 and the sub shaft 14, and the second step continuously variable transmission is performed between the sub shaft 14 and the output shaft 12. Therefore, the greatest merit is that the speed ratio width is a value obtained by multiplying the speed ratio widths of the first stage and the second stage, and a large speed ratio width can be obtained.
As for power transmission efficiency, the bearing loss is slightly larger than that in the first embodiment, but it is significantly larger than that in the case where two conventional continuously variable transmissions are connected in series in order to secure the above-described large gear ratio range. It can be said that it will be higher.

Next, a continuously variable transmission according to Embodiment 3 of the present invention will be described below.
FIG. 7 is a skeleton diagram of the continuously variable transmission according to the third embodiment.
Here, the description will focus on parts that are different from the first embodiment, and parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

The difference between the third embodiment and the first embodiment is that the auxiliary shaft 14 drives the differential device 60 provided in parallel therewith. That is, the drive gear 46 b drives the driven gear 60 a that is integral with the differential device 60.
The differential device 60 drives a wheel (not shown) via the axles 60b and 60c.
Further, the number of the counter shaft 14 is one, the first ball 20 and the second ball 30 are also configured in a pair, and have the first and second support rings 50 and 52 and the like in the first embodiment. Not.
Others are the same as in the first embodiment, and a description thereof will be omitted.
When a plurality of the countershafts 14 are provided, the drive gears 46b of the respective subshafts 14 are connected to each other, and therefore, it is only necessary to additionally provide the driven gear 12a drawn by a broken line that meshes with them. Only one countershaft 14 needs to drive 60.

Next, the operation of the continuously variable transmission according to the third embodiment shown in FIG. 7 will be described. Basically, the continuously variable transmission between the input shaft 10 and the auxiliary shaft 14 is the same as described in the first embodiment. Therefore, the description is omitted.
The third embodiment is a configuration suitable for use in a front-wheel drive vehicle in which the engine is installed horizontally. In particular, when the number of the countershaft 14 is one, it can be made more compact and lighter than the conventional example.

Next, a continuously variable transmission according to Embodiment 4 of the present invention will be described below.
FIG. 8 is a skeleton diagram of the continuously variable transmission according to the fourth embodiment.
Here, the description will focus on parts that are different from the first embodiment, and parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

The difference of the fourth embodiment from the first embodiment is that, in addition to the first ball 20 and the second ball 30 provided between the input shaft 10 and the countershaft 14, the driving gear 46b and the driven gear 12a in the first embodiment are different. Instead, the third ball 64 and the fourth ball 66 are also provided between the auxiliary shaft 14 and the output shaft 12 whose axial length is extended, and the fifth disk 68 and the sixth disk 70 are provided on the auxiliary shaft 14. The seventh disk 72 and the eighth disk 74 are provided on the output shaft 12 respectively.
Although detailed illustration and description are omitted, the configuration between the output shaft 12 and the sub shaft 14 is basically symmetric and similar to the configuration between the input shaft 10 and the sub shaft 14. The sizes of the first ball 20, the second ball 30, the third ball 64, and the fourth ball 66 may be different.

Next, the operation of the continuously variable transmission according to the fourth embodiment shown in FIG. 8 is similar to that explained in the second embodiment, and the first shaft 40, the first disk 40, and the second disk 42 The first CVT 1 reaching the auxiliary shaft 14 via the one ball 20, the second ball 30, the third disc 44, and the fourth disc 46, the extended auxiliary shaft 14, the fifth disc 68, the sixth disc 70, and the third ball 64 Then, two-stage continuously variable transmission of the second CVT 2 reaching the output shaft 12 through the fourth ball 66, the seventh disk 72 and the eighth disk 74 is performed.
Therefore, as in the second embodiment, the speed ratio can be increased.
Even in the fourth embodiment, a plurality of the countershafts 14 are provided, and the first and second support rings 50 and 52 as shown in the first embodiment can be provided to further improve the power transmission efficiency.

  As described above, the continuously variable transmission according to each embodiment of the present invention is provided with the first ball 20 and the second ball 30 as a pair between the input shaft 10 and the auxiliary shaft 14. Thrust received from these four discs 40, 42, 44, 46 between the first disc 40, the second disc 42 on the side and the third disc 44, the fourth disc 46 on the side of the countershaft 14 from four directions Is offset at the contact point between the first ball 20 and the second ball 30, and therefore, the thrust does not act on the bearing that supports the input shaft 10 and the auxiliary shaft 14.

Further, when a plurality of sub-shafts 14 are provided, it is possible to cancel the radial load between the plurality of sub-shafts 14 by the first support ring 50 or the like, all of which contribute to the improvement of power transmission efficiency. There is a merit.
In addition, as described in the second and fourth embodiments, it is a feature that a large speed ratio range can be secured even though it is a single continuously variable transmission, and there is an advantage in improving the fuel consumption of an automobile or the like.

  Based on the general knowledge of those skilled in the art, the continuously variable transmission of the present invention can be driven in reverse rotation in combination with a planetary gear train, or can be provided with a torque converter or the like to smoothly start the vehicle. It can implement in the aspect which added.

  The continuously variable transmission of the present invention can be widely applied to vehicles such as automobiles and bicycles that are particularly required to have high power transmission efficiency, and various rotating machines such as machine equipment and wind power generators.

DESCRIPTION OF SYMBOLS 10 Input shaft 12 Output shaft 14 Sub shaft 20 1st ball 22 1st ball shaft 28 1st stator 28
30 Second Ball 32 Second Ball Shaft 38 Second Stator 40 First Disc 42 Second Disc 44 Third Disc 46 Fourth Disc 50 First Support Ring 52 Second Support Ring

Claims (6)

An input shaft;
An output shaft;
A secondary shaft arranged parallel to the input shaft and the output shaft;
Case and
A stator that can be locked to the case;
A first ball shaft and a second ball shaft, which are disposed between the input shaft and the sub shaft so as to be tiltable to the stator;
Two first balls and second balls which are rotatably supported by the first ball shaft and the second ball shaft, respectively, and are in contact with each other directly or through a contact via a bearing,
A first disk having a friction surface capable of transmitting power in contact with the first ball, and a friction surface capable of transmitting power in contact with the second ball, the rotation direction being integrated with the input shaft or the output shaft. A disc,
A third disk having a friction surface in which the countershaft and the rotation direction are integral and having a friction surface capable of transmitting power in contact with the first ball; and a fourth disk having a friction surface capable of transmitting power in contact with the second ball; With
A thrust acting on the first ball and the second ball from the first disk and the second disk, and a thrust acting on the first ball and the second ball from the third disk and the fourth disk. The continuously variable transmission is offset by the contact points of the first ball and the second ball.   A plurality of the auxiliary shafts are provided, a guide groove is formed in a sleeve provided outside the input shaft, and the input shaft side end portions of the first ball shaft and the second ball shaft are engaged with the guide groove. The continuously variable transmission according to claim 1.   3. The input shaft, the first disk, and the second disk are integrated in a rotational direction, and the auxiliary shaft and the output shaft are connected by a gear. Continuously variable transmission.   The continuously variable transmission according to any one of claims 1 to 3, further comprising a ring or a sleeve having an outer periphery of the auxiliary shaft or an inner surface in contact with an outer surface of a cone formed on the third disk and the fourth disk. .   The continuously variable transmission according to claim 4, wherein the auxiliary shaft is supported by the case so as to be movable in a radial direction. The continuously variable transmission according to any one of claims 1 to 5, wherein the stator is rotatable in a predetermined range about the input shaft.

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