JPH0567822B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a transmission that is used as an automatic transmission in which the gear ratio changes automatically according to the load or a continuously variable transmission in which the gear ratio is changed steplessly. Regarding.

Prior Art and Problems of the Invention As a transmission used as an automatic transmission or a continuously variable transmission, a plurality of spherical or conical rolling elements that rotate and revolve are interposed between an input shaft and an output shaft. One using a friction planetary mechanism is known.

However, such conventional transmission devices have the following problems.

That is, due to its structure, the speed change range is relatively small.
In addition, a spring such as a disc spring is required to maintain the sliding state of the rolling elements, and since the sliding contact point with the rolling elements is always constant, local wear occurs and the service life is short.

An object of the present invention is to provide a transmission that solves all of the above problems.

Means for Solving the Problems A transmission device according to the present invention includes an input shaft, an output shaft disposed coaxially with the input shaft, and a retainer coaxially and rotatably disposed around the input shaft and the output shaft. , a cylindrical member arranged around a cage so as to be movable coaxially and in the axial direction, and a plurality of rolling elements held by the cage so as to be able to rotate about their own axis. A first guide surface perpendicular to the axis of the input shaft is provided on the input shaft or a part that rotates together with the input shaft, and a second guide surface tapered at 45 degrees is provided on the output shaft or a part that rotates together with the input shaft. An annular guide groove having an arcuate cross-sectional shape is provided on the inner peripheral surface of the cylindrical member, the rolling element has a substantially cylindrical shape, and a rounded part is provided around the entire outer periphery of one end of the rolling element. , a spherical part having a center on the axis of the rolling element is provided on the other end surface, two symmetrical places of the rounded part of the rolling element contact the first guide surface and the bottom of the guide groove, and the spherical part of the rolling element contacts the second symmetrical part of the rounded part of the rolling element. It is brought into contact with the guide surface.

Function Since the rounded portion of the rolling element fits into the guide groove of the cylindrical member, the inclination of the rolling element changes as the cylindrical member moves in the axial direction. By appropriately determining the radius of the spherical part of the rolling element,
Even if the inclination of the rolling element changes, the rolling element can always be kept in contact with the first guide surface, the second guide surface, and the guide groove. Therefore, there is no need for a disc spring or the like to maintain the sliding state of the rolling elements, and there is no need to consider deterioration of the spring. Furthermore, when the inclination of the rolling elements changes, the contact points of the rolling elements and the contact points with the rolling elements change, thereby reducing local wear.

The rotation of the input shaft is transmitted to the rolling elements, and the rolling elements rotate while contacting the first guide surface, the second guide surface, and the guide groove, and the differential action at this time causes the input shaft to rotate. The rotation is changed in speed and transmitted to the output shaft. As the inclination of the rolling elements changes, the gear ratio changes, and the inclination of the rolling elements can be changed significantly, resulting in a very wide speed change range.

Embodiment Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The drawing shows an example of an automatic transmission that automatically changes the gear ratio depending on the load. In addition, in the following explanation, upper, lower, left, and right refer to FIG. 1.

1 and 2, the transmission includes a case 1, an input shaft 2, an output shaft 3, a cage 4, a cylindrical member 5, and a plurality of rolling elements 6, for example, five.

The case 1 has a cylindrical shape and is arranged so that the axis C is a horizontal line in the left-right direction. An end wall 1a having a circular hole 7 in the center is provided at the left end of the case 1. The right end of case 1 is open,
A cylindrical bearing housing 8 is coaxially fixed inside this part. A flange portion 8a is integrally formed at the right end of the housing 8, and this portion is fitted inside the right end portion of the case 1. The input shaft 2 and the output shaft 3 are coaxially arranged on the axis C of the case 1 so that the input shaft 2 is on the left and the output shaft 3 is on the right.

A hole 9 is formed on the axis C of the input shaft 2, extending from the left end surface to the middle of the length. A flange portion 2a is coaxially formed at the middle part of the length of the input shaft 2, an input member support shaft portion 2b is on the right side of the flange portion 2a, and a connecting shaft portion 2c with a smaller outer diameter is further on the right side of the flange portion 2a.
are formed coaxially. Support shaft part 2 of input shaft 2
A perforated disk-shaped input member 10 is rotatably fitted on the outside of b. Flange part 2 of input shaft 2
A plurality of sets of conical recesses 11 and 12 are formed on the facing surface of the input member 10 so as to face each other at equal intervals in the circumferential direction, and the opposite recesses 11 and 12
A steel ball 13 is fitted between them. The right end surface of the input member 10 serves as a first guide surface 14 orthogonal to the axis C of the input shaft 2. The rotation of the input shaft 2 is transmitted to the input member 10 via the steel ball 13 between the recesses 11 and 12. At this time, the steel ball 13 hits the conical walls of the recesses 11 and 12, so the input shaft 2
Due to the rotation, the input member 10 receives a force in the direction away from the flange portion 2a, that is, in the right direction.

On the axis C of the output shaft 3, a first hole 15 reaching the middle part of the length from the left end face and a second hole 16 reaching the middle part of the length from the right end face are formed. Output shaft 3
A large diameter part 3a having a larger outer diameter than other parts is located at the left end of the
are formed coaxially, and a second guide surface 17 tapered at 45 degrees is formed at the left end of the outer periphery of the large diameter portion 3a.

Connecting shaft portion 2 of input shaft 2 to first hole 15 of output shaft 3
c is rotatably fitted into the case 1 and the housing 8 via bearings 18, 19, 20 so that the input shaft 2 and output shaft 3 connected in this way can rotate independently of each other. Supported. That is, the first thrust ball bearing 18 is located between the left side portion of the flange portion 2a of the input shaft 2 and the inner peripheral portion of the left end portion 1a of the case 1;
A second thrust ball bearing 19 is provided between the right side portion of the output shaft 3 and the left end portion of the housing 8, and a radial ball bearing 20 is provided between the right side portion of the output shaft 3 and the right side portion of the housing 8. It is being
The input shaft 2 projects slightly from the left end wall 1a of the case 1, and a seal 21 is provided between them. The output shaft 3 protrudes a little from the right end of the housing 8, and a seal 22 is also provided between them.

The cage 4 has a cylindrical shape with steps on the inner and outer surfaces, as shown in the cross-sectional shape at the bottom of FIG. It is rotatably received on the outer surface of the large diameter portion 3a. Five pockets 23 for supporting the rolling elements 6 are formed in the cage 4 at equal intervals in the circumferential direction.

The cylindrical member 5 is arranged on the inner surface of the case 1 around the retainer 4 so as to be rotatable and axially movable. As shown in FIG. 3, the cylindrical member 5 is formed with a long hole 24 that is inclined with respect to a direction parallel to the axis C. On the inner surface of the case 1, a pin 25 is fixedly provided in the elongated hole 24 and for regulating the movement of the cylindrical member 5. Furthermore, a shallow guide groove 26 having an arcuate cross section is formed in an annular shape on the inner surface of the cylindrical member 5 on the right side of the elongated hole 24 .

As shown in detail in FIG. 4, the rolling element 6 has a short cylindrical shape, and has a rounded part 6a with a radius a around the entire outer periphery of one end, and a radius b centered on the axis A on the other end surface. A spherical portion 6b is provided. The rolling element 6 has the first guide surface 1 at two symmetrical locations of the rounded portion 6a.
4 and the bottom of the guide groove 26, and the spherical part 6b is accommodated in the pocket 23 of the retainer 4 with the axis A tilted so that it contacts the second guide surface 17. The outer surface of the intermediate cylindrical portion of the rolling element 6 is received by walls on both circumferential sides of the pocket 23, so that the rolling element 6 rotates about its axis A. Furthermore, the rolling elements 6 revolve around the input shaft 2 and the output shaft 3 as the cage 4 rotates. In the cross-sectional view of FIG. 4, a vertical line L1 is located on the right side of the first guide surface 14 and is spaced apart by the radius a of the rounded portion 6a, and a horizontal line L2 is located below the bottom of the guide groove 26 and spaced apart by the radius a of the rounded portion 6a. Assuming that the intersection point is 0, the distance from this intersection point 0 to the second guide surface 17 is the radius b of the spherical portion 6b.

A compression coil spring 27 that urges the cylindrical member 5 leftward is provided between the flange portion 8a around the housing 8 and the right end surface of the cylindrical member 5.

In the above-described transmission, when the cylindrical member 5 moves left and right, the rounded portion 6a of the rolling element 6, which is fitted in the guide groove 26, moves left and right while remaining in the guide groove 26, thereby causing the rolling element 6 to move left and right. The inclination of (the inclination of axis A) changes. However, since there is the above-mentioned dimensional relationship between the first guide surface 14, the second guide surface 17, the guide groove 26, the rounded part 6a and the spherical part 6b of the rolling element 6, as shown in FIG. Even if the inclination of the rolling element 6 changes, the contact state between the rolling element 6 and the guide surfaces 14, 17 and the guide groove 26 is always maintained. Furthermore, as described above, due to the rotation of the input shaft 2, the input member 10 receives a rightward force that causes it to approach the rolling elements 6, so that the rolling elements 6 are prevented from coming into contact with the guide surfaces 14, 17 and the guide grooves 26. Become more certain. Therefore, there is no need to use a disc spring or the like to bring the rolling elements 6 into contact, and it is no longer necessary to consider deterioration of the spring. Then, the rotation of the input member 10 due to the rotation of the input shaft 2 is transmitted to the rolling elements 6, and the rolling elements 6 rotate while contacting the guide surfaces 14, 17 and the guide grooves 26, and the difference at this time is Depending on the operation, the rotation of the input shaft 2 is changed in speed and transmitted to the output shaft 3.

In FIG. 5, the rolling elements 6 and the first guide surface 14
The distance from the contact point (first contact point) P1 with the axis C is R1, the distance from the first contact point P1 to the axis A is r1, and the contact point between the rolling element 6 and the second guide surface 17 (the second The distance from contact point) P2 to axis C is R
2. The distance from the second contact point P2 to the axis A is r
2. Contact point between rolling element 6 and guide groove 26 (third
Contact point) The distance from P3 to axis C is R3, the third
The distance from the contact point P3 to the axis A is defined as r3.
When the inclination of the rolling element 6 changes, R3 remains constant, but
R1, R2, r1, r2, and r3 change, thereby changing the speed ratio (ratio of the rotational speed of the output shaft 3 and the rotational speed of the input shaft 2). Regarding the second contact point p2, when the inclination of the rolling element 6 is small, the fifth contact point p2
As shown in figures a and b, the first
Although it is on the same side as the contact point P1, when the inclination of the rolling element 6 is large, as shown in c and d of the figure,
The second contact point P
2 changes significantly, it becomes possible to change the gear ratio over a wide range. Moreover, when the inclination of the rolling element 6 changes, the first contact point P on the first guide surface 14
1. The second contact point P2 on the second guide surface 17, the first contact point P1, the second contact point P2, and the third contact point P3 on the rolling element 6 also change, and therefore local wear occurs. becomes smaller.

In the above transmission, when the load on the output shaft 3 changes, the torque acting on the cylindrical member 5 changes, so the position of the cylindrical member 5 in the axis C direction changes due to the action of the pin 25 and the elongated hole 24. As a result, the inclination of the rolling elements 6 changes automatically as described above.
That is, when no load is acting on the output shaft 3, the cylindrical member 5 is moved by the spring 2 as shown in FIG. 5a.
7 to the left end position, and the rolling element 6
The slope of is small. When a load acts on the output shaft 3,
The cylindrical member 5 moves to the right against the spring 27, and the inclination of the rolling element 6 increases. The amount of movement of the cylindrical member 5 at this time corresponds to the magnitude of the load, and as the load increases, the inclination of the rolling element 6 increases in the order of FIGS. 5b, 4, 5c and d.

As shown in FIG. 5a, when no load is acting on the output shaft, the gear ratio is greater than 1, and the output shaft 3 rotates in the same direction as the input shaft 2 at a speed greater than that of the input shaft 2. That is, the rotation of the input shaft 2 is accelerated in the same direction and transmitted to the output shaft 3. For example, the gear ratio at this time is approximately 1.12.

When the load increases from a no-load state, the gear ratio gradually decreases, and when the state shown in Fig. 5b is reached, the gear ratio becomes 1, and the rotation of the input shaft 2 is directly transmitted to the output shaft 3. 3 rotates in the same direction and at the same speed as the input shaft 2.

When the load becomes larger, the gear ratio becomes smaller than 1, and the output shaft 3 rotates in the same direction as the input shaft 2 at a speed lower than that of the input shaft 2. That is, the rotation of the input shaft 2 is decelerated in the same direction and transmitted to the output shaft 3. For example, in the state shown in FIG. 4, the gear ratio becomes approximately 0.61, and as the load increases further, the gear ratio becomes even smaller.

When the state shown in Fig. 5c is reached, the gear ratio becomes 0,
The output shaft 3 stops when its rotational speed becomes 0.

In the state shown in FIG. 5d, the gear ratio becomes a negative value, and the output shaft 3 rotates in the opposite direction to the input shaft 2 at a speed lower than that of the input shaft 2. That is, the rotation of the input shaft 2 is decelerated in the opposite direction and transmitted to the output shaft 3. For example, the gear ratio at this time is approximately -0.1.

In this way, in the above-mentioned transmission, the gear ratio changes automatically according to the load on the output shaft 3, and moreover, the gear ratio changes over a very wide range, for example, from about -0.1 to about 1.12.

Although the automatic transmission is shown in the above embodiment, if the cylindrical member 5 is moved in the axial direction by an appropriate means and fixed at a predetermined position, the gear ratio can be changed steplessly from the outside. It becomes a transmission.

Effects of the Invention According to the transmission device of the present invention, as described above,
The speed change range can be made very wide, and local wear of the rolling elements can be reduced. Further, there is no need for a disc spring or the like to maintain the sliding state of the rolling elements, and there is no need to consider deterioration of the spring.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an automatic transmission showing one embodiment of the present invention, FIG. 2 is a sectional view taken along the line shown in FIG. 1, FIG. 3 is a sectional view taken along the line taken in FIG. 1, and FIG. An enlarged sectional view of the rolling element part in Figure 1, Figure 5 is 4
FIG. 3 is a cross-sectional view of a portion of the rolling element showing two different speed change states. 2...Input shaft, 3...Output shaft, 4...Retainer,
5... Cylindrical member, 6... Rolling element, 6a... Rounded part, 6b... Spherical part, 10... Input member, 14...
...First guide surface, 17...Second guide surface, 26...
...Guide groove, A...Axis line, C...Axis line.

Claims (1)

[Claims] 1. An input shaft, an output shaft disposed coaxially with the input shaft, a retainer coaxially and rotatably disposed around the input shaft and the output shaft, and a retainer coaxially disposed around the retainer. It is equipped with a cylindrical member arranged so as to be able to move in the axial direction, and a plurality of rolling elements held in a cage so as to be able to rotate about its own axis, and is connected to the input shaft or integrally therewith. A first guide surface perpendicular to the axis of the input shaft is provided on the part that rotates, and a second guide surface tapered at 45 degrees is provided on the output shaft or a part that rotates integrally with the output shaft. An annular guide groove with an arcuate cross-sectional shape is provided on the circumferential surface, the rolling element is approximately cylindrical, a rounded portion is provided around the entire outer periphery of one end of the rolling element, and a rounded portion is provided on the other end surface of the rolling element. A spherical part having a center on the axis is provided, two symmetrical places of the rounded part of the rolling element are in contact with the first guide surface and the bottom of the guide groove, and the spherical part of the rolling element is brought into contact with the second guide surface. transmission gear.