JP2000291759A - Continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a weight and to improve the efficiency and durability by mounting an input cone inside a ring, mounting an output cone outside the ring for holding the ring by both cones, frictionally transmitting the rotary torque of the input cone to the output cone, and changing a gear by longitudinally moving the ring. SOLUTION: A continuously variable transmission is formed by mounting an input shaft 2 to a machine frame 1, and connecting an input cone 4 to an end of the input shaft 2. A first ring 7 for transmitting rotation is held by the input cone 4 and a first output cone 5, a second ring 10 for transmitting rotation is held by the input cone 4 and a second output cone 8, and an output shaft 11 is rotatably mounted on the machine frame 1 coaxially with the input core 4. A ring holding mechanism 16 converts the rotary torque of the input shaft 2 into the thrust force, and presses the input cone 4 in the axial longitudinal direction for holding the first ring 7 and the second ring 10 with the output cones 5, 8 with a predetermined surface pressure. The output shaft 11 is rotated by the rotation of the output cones 5, 8 through the gears 13, 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission used for trackless transport machines such as automobiles and ships, various manufacturing machines, processing machines and the like.

[0002]

2. Description of the Related Art In general, an electric motor which is a driving source of a rotary driving device used for a track transport machine, various manufacturing machines, etc.
2. Description of the Related Art A gear that efficiently shifts with an electric transmission device such as an inverter has become widespread.

[0003] However, in trackless transport machines that cannot easily receive power, various manufacturing machines installed in places where power cannot be easily received, or mobile processing machines, diesel engines and gasoline engines are used. In order to shift the power of the prime mover to a predetermined number of revolutions, a transmission is required, and development of a lightweight, highly efficient, and durable mechanical continuously variable transmission is desired.

The mechanical type continuously variable transmission has been developed and put to practical use as one of important mechanical devices for a long time, and the main one is a combination of a belt and a pool or a combination of a cone and a ring. is there.

[0005] The above-described continuously variable transmission combining a cone and a ring has, for example, an input cone 80 as shown in FIGS.
, An output cone 81, a ring 82, and a ring guide mechanism 83.
And the output cone 81 are arranged so that the taper directions are opposite to each other, and the outer peripheral surfaces of the input cone 80 and the output cone 81 are brought into contact with the inner peripheral surface of the ring 82. , Ring 82 and output cone 8
The rotation of the input cone 80 is transmitted to the output cone 81 by the frictional force with the output cone 81.

In the continuously variable transmission having the above configuration, the input cone 8
When the rotation speed of the output cone 81 is changed with respect to the rotation speed of 0, the ring 82 is moved in the longitudinal direction of the axis of each cone.

[0007] In a continuously variable transmission of a friction transmission system, traction oil is used for the purpose of preventing wear of a contact point and increasing transmission force.

[0008]

In the former case of the above-mentioned continuously variable transmission, in order to improve the durability, the contact area between the cone and the ring is increased or the pressing force is reduced to reduce the pressure at the contact point. It is necessary to reduce the size of the continuously variable transmission, which causes a problem that the size and weight of the continuously variable transmission are increased.

If the contact area is simply increased to improve the durability, the contact at a portion having a different speed ratio with respect to the pitch line which determines the speed ratio increases, the friction due to slip increases, and the rotation transmission efficiency decreases. Therefore, there is a problem that a device for increasing the contact area having the same speed ratio along the pitch line is required.

Further, of the stresses applied to the components constituting the apparatus, the pressing force of the contact portion for transmitting the power and the range for applying the frictional force are narrowed as much as possible, so that the working range of the unnecessary stress is applied. There is a problem that must be devised to narrow the.

Further, when shifting the output shaft, the ring is moved in the direction of rotation of the ring by a ring guide mechanism. However, when the rotation axis of the ring is tilted, the contact point of either the input cone or the output cone is reduced. Although a force acts in the direction in which it is desired to move, a force acts in the opposite direction at the other contact point, so that the ring is in a stiff state and cannot be moved smoothly. Therefore, high precision to move so that the rotation axis of the ring does not tilt,
There is a problem that it is necessary to install a highly rigid ring guide mechanism.

In the case of the above-described continuously variable transmission, although the traction oil has been developed and its performance has been improved, the traction coefficient has a value of at most 0.1. It is necessary that the frictional force transmitting the pressing force in the section be at least 10 times the frictional force. Rings and the like need to have sufficient rigidity to cope with this pressing force, but the transmission is limited by the material, strength, etc. There is a problem that the transmission capacity is relatively small as compared with the weight of the.

SUMMARY OF THE INVENTION An object of the present invention is to provide a continuously variable transmission capable of simultaneously achieving weight reduction, efficiency improvement and durability improvement.

[0014]

According to a first aspect of the present invention, there is provided a continuously variable transmission in which one of an input cone and an output cone is disposed at a position inside the ring. The other of the input cone or the output cone is disposed so as to be located outside the ring, and the cross-sectional shape of the ring is adjusted so that the surfaces contacting the input cone and the output cone are respectively convex smooth curves. The ring is pressed between the input cone and the output cone to transmit the rotational torque of the input cone to the output cone via the ring, and the ring guide mechanism is used to adjust the rotation axis of the input cone and the output cone. In the space divided into two by the geometric plane including the ring, the ring is installed in a space in front of a clamping portion where the ring is clamped by the input cone and the output cone. By Gugaido mechanism is characterized in that so as to shift by moving in the axial longitudinal direction of the input cone and output cone ring.

The continuously variable transmission according to the present invention comprises a plurality of units, one of an input cone and an output cone, a ring, and a ring guide mechanism. The ring guide mechanism according to claim 3, wherein the other one of the output cones is one, wherein the ring guide is constrained in a geometric plane perpendicular to a speed change movement direction of the ring guide, and The ring guide may be rotatably supported at a position for guiding the ring in the geometric plane.

[0016]

FIG. 1 is a schematic sectional view showing a first embodiment of the configuration of a continuously variable transmission according to the present invention, and FIG. 2 is a view taken along the line II in FIG. An input shaft 2 rotatably mounted on a machine frame 1 by a bearing 3, an input cone 4 connected to an end of the input shaft 2, and a first ring 7 for transmitting rotation are connected to the input cone 4. A first rotatably mounted by a bearing 6 on the machine frame 1 so as to be sandwiched by
An output cone 5, a second output cone 8 rotatably mounted on the machine frame 1 by a bearing 9 such that a second ring 10 for rotation transmission is sandwiched by the input cone 4, and a coaxial shaft with the input cone 4. An output shaft 11 rotatably mounted on the machine frame 1 by bearings 12 so as to be centered, and a gear 13 for transmitting rotation of the first output cone 5 and the second output cone 8 to a gear 15 mounted on the output shaft 11, respectively. 14
The first ring is provided between the input shaft 2 and the input cone 4 and converts the rotational torque of the input shaft 2 into a thrust force acting in the axial longitudinal direction to press the input cone 4 in the axial longitudinal direction. A ring narrow pressure mechanism 16 for narrowing the first ring 7 and the second ring 10 with a predetermined surface pressure by the first output cone 5 and the second output cone 8, and a shaft of the input cone 4 for the first ring 7 and the second ring 10. It comprises ring guide mechanisms 17 and 18 for moving in the longitudinal direction of the heart.

As shown in FIG. 3, the sectional shapes of the first ring 7 and the second ring 10 are the outer peripheral surface of the first ring 7 and the second output cone 8 which are in contact with the outer peripheral surface of the input cone 4. The radius of curvature between the inner peripheral surface and the inner peripheral surface is R1, R2.
Are each processed into a smooth convex surface. When the curvature radii R1 and R2 are increased, the input cone 4 or the first
The area of the Hertzian stress ellipse formed at the contact portion between the output cone 5 and the second output cone 8 can be increased and the load capacity can be increased, but the contact at a point away from the pitch line that determines the gear ratio increases. As a result, the rotation transmission efficiency is reduced. Therefore, it is preferable that the curvature radii R1 and R2 be set in a range of 1/10 to 10 times the radius of the ring.

In order to make the magnitude of the Hertzian stress acting on the front and back of the contact portion of the ring as uniform as possible, the radius of curvature is smaller in the case of inscribed than in the case of circumscribed by the contact method with the counterpart cone. It is desirable.

The first ring 7 and the second ring 10 are generally made of a material such as bearing steel used for a rolling bearing in view of wear resistance, load resistance, deformation resistance and the like, and the convex portion has a roughness. The mirror surface is processed so as to have a hardness of HRC60 or more.

As shown in FIG. 4, the ring guide mechanism 17 includes a ball screw shaft 19 rotatably mounted on the machine frame 1 in a state parallel to the outer peripheral surfaces of the input cone 4 and the first output cone 5, A bracket 21 is attached to the ball screw shaft 19 by a ball screw nut 20 so as to be movable in the longitudinal direction of the axis of the ball screw shaft 19 and to be rotatable on the ball screw shaft 19. An arm member 22 movably attached and a ring guide rotatably supporting the first ring 7 and rotatably attached to the arm member 22 in the X-axis direction, the Y-axis direction, and the Z-axis direction. When the ball screw shaft 19 is rotated forward and backward by a driving device (not shown), the bracket 21 moves in the longitudinal direction of the axis of the ball screw shaft 19. It has become way.

The spherical guide 23 is provided with a through-hole so that the first ring 7 can rotate smoothly in the circumferential direction. The spherical guide 23 has an input cone 4 and each output cone 5.
Is restricted in a geometric plane perpendicular to the direction of movement for shifting gears, but is rotatable, and changes the attitude of the first ring 7 slightly by changing the frictional transmission force of the power applied to the first ring 7. Is rotatably supported on the geometric plane while maintaining the gear ratio.

The spherical guide 23 of the ring guide mechanism 17
As shown in FIG. 2, the first ring 7 is divided into two parts (both sides of the dashed line) in a space in which the first ring 7 is bisected by a geometric plane including the axis of the input cone 4 and the axis of the first output cone 5. The first ring 7 is arranged at a position on the near side of a position where the pressure is narrowed by the input cone 4 and the first output cone 5, that is, an upstream position in the rotation direction of the first ring 7. When the spherical guide 23 is disposed at this position, the spherical guide 23 rotates stably at a position guided by the spherical guide 23 without providing another member for determining the rotational position of the first ring 7.
Is moved along the input cone 4 and the first output cone 5, the point where the first ring 7 is narrowed by the input cone 4 and the first output cone 5 follows the spherical guide 23 and moves to output. The shift of the shaft 11 is performed.

The spherical guide 23 is manufactured so that it can be divided into two in the above-mentioned geometric plane.

The above-described ring guide mechanism 18 has the same configuration as the ring guide mechanism 17, and is configured to move the second ring 10 along the outer peripheral surfaces of the input cone 4 and the second output cone 8. The ring guide mechanism 18 is configured to control each driving device (not shown) so as to operate in synchronization with the ring guide mechanism 17 or to operate two ring guide mechanisms by one driving device.

When the output shaft 11 of the continuously variable transmission rotates forward and backward, a ring guide mechanism is provided on each side of a geometrically divided space including the rotation shafts of the input cone and the output cone, respectively, so as to press the ring. The ring guide mechanism arranged on the front side of the section is operated to move the ring, and the ring guide mechanism on the opposite side is made to follow the ring.

It goes without saying that in the above-described continuously variable transmission, the output shaft can be changed to the input shaft and the input shaft can be changed to the output shaft.

In the above-described continuously variable transmission, the ring is formed such that the surfaces contacting the input cone and the output cone have smooth convex curves, respectively, so that the ring is pressed by the input cone and the output cone. Because
The pressing force required to transmit the transmission force due to friction is concentrated so as to penetrate both surfaces of the narrow pressure portion of the ring, and generates compressive stress and shear stress inside the narrow pressure portion. The ring does not need to have great rigidity because it is limited to the pressure section and does not cover the entire ring. Therefore, the thickness can be reduced and the weight can be reduced.

Also, the ring guide mechanism is provided in a space divided into two by a geometric plane including the rotation axes of the input cone and the output cone, before the clamping portion where the ring is clamped by the input cone and the output cone. It is installed in the space on the side, and the ring is moved by the ring guide mechanism in the longitudinal direction of the axis of the input cone and output cone, so that there is no other member to determine the rotational position of the ring. Even when the spherical guide rotates stably at a predetermined position guided by the spherical guide, which is a ring guide, and the spherical guide is moved along the input cone and the output cone, the ring is narrowed by the input cone and the first output cone. Point can follow the spherical guide to shift the output shaft, and a simple continuously variable transmission having a small number of parts can be formed. In both cases, the ring is inclined in the moving direction of the ring guide mechanism (spherical guide), and follows the moving direction of the spherical guide in a state where the pressure is narrow, so that the ring can be moved with a small force and the ring guide mechanism is downsized. ,
The weight can be reduced.

Further, one of the input cone and the output cone, the ring, and the ring guide mechanism are connected to each other by two.
A unit or a plurality of units such as three units, and the other of the input cone or the output cone is configured as one, so that high load transmission can be achieved and the plurality of units can be arranged at equal intervals. , The pressing force acting on the narrow pressure section becomes symmetrical with respect to the axis of the input cone or the output cone, making it possible to easily design the structure of the machine frame that receives the reaction force and reduce the weight. be able to.

The above-described continuously variable transmission can be said to be a circumscribed type continuously variable transmission because the ring needs to contact the outer peripheral surfaces of the input cone and the output cone.

The continuously variable transmission of the present invention can also be implemented with an inscribed type configuration. FIG. 5 is a schematic sectional view showing a second embodiment of the configuration of the continuously variable transmission of the present invention, and FIG. I in FIG.
FIG. 2 is a view taken in the direction of arrows I-II, wherein an input shaft 32 rotatably mounted on the machine frame 31 by a bearing 33, a conical input cone 34 rotatably mounted on the machine frame 31 by a bearing 35, A first output cone 36 and a spacer 37 that are inserted into a shaft 38 that is rotatably mounted on a machine frame 31 by bearings 39 so that a first ring 40 for transmission is sandwiched by the inner peripheral surface of the input cone 34. And a second output cone 41 and a spacer 42, which are inserted into a shaft 43 rotatably attached to the machine frame 31 by a bearing 44 so as to sandwich the second ring 45 with the inner peripheral surface of the input cone 34. And the third ring 47 is inserted into a shaft (not shown) rotatably mounted on the machine frame 31 by a bearing (not shown) so as to be sandwiched by the inner peripheral surface of the input cone 34. A third output cone 46 and a spacer (not shown), an output shaft 48 rotatably mounted on the machine frame 31 by a bearing 49 so as to be located at the center of each of the output cones 36, 41, 46, and an input shaft. A gear 50 attached to the input shaft 32 that transmits the rotation of the output cone 32 to a gear 34a formed on the input cone 34;
The gears 5 attached to the output shaft 48 rotate the rotations 41 and 46.
3, the gears 51 and 52 (bearings of the third output cone 46 are not shown), between the first output cone 36 and the spacer 37, between the second output cone 41 and the spacer 42, and between the third output cone 46 and Attached to the shafts 38, 43 and the like so as to be positioned between spacers (not shown), the rotational torque of each output cone 36, 41, 46 is converted into a thrust force acting in the longitudinal direction of the axis, and each output cone 36 , 41, 46 in the longitudinal direction of the axis to make the first ring 40 and the second ring 45
Ring narrowing mechanisms 54 and 55 (the ring narrowing mechanism provided between the third output cone 46 and a spacer (not shown)) for narrowing the third ring 49 with the input cone 34 with a predetermined surface pressure. A ring guide mechanism 5 for moving the first ring 40, the second ring 45, and the third ring 47 along the inner peripheral surface of the input cone 34 in the axial longitudinal direction.
6, 57, and 58.

The above-described rings 40, 45, 47 and the respective ring guide mechanisms 56, 57, 58 are the same as the respective rings 7, 10 and the ring guide mechanism 17 in the first embodiment, and will not be described.

An input cone 34 and each output cone 36,
There are three geometric planes including the rotation axes 41 and 46, as indicated by the chain line.

The internal-type continuously variable transmission is characterized in that the contact between the input cone 34 and each of the rings 40, 45 and 47 and the contact between each of the rings 40, 45 and 47 and each of the output cones 36, 41 and 46 are made. It is inscribed, and all the contact parts that transmit power frictionally are inscribed.

It is generally known that when a bearing is a rolling bearing, a Hertzian stress is generated at a contact point of the rolling bearing, and its magnitude determines the bearing load capacity and life. .

In the case of the inscribed type continuously variable transmission, the contact area on which the Hertzian stress acts is larger in the inscribed type continuously variable transmission than in the circumscribed type continuously variable transmission. The stress is reduced, the load capacity is increased, and the life is extended.

Further, since the contact area is long along the pitch line that determines the gear ratio, the transmission efficiency, which is an important measure for the transmission, can be maintained at a high level, and a long life with a high load can be achieved. .

Further, it goes without saying that the same operation and effect as those of the circumscribed continuously variable transmission of the first embodiment can be obtained.

[0039]

According to the continuously variable transmission of the present invention, one of the input cone and the output cone is located at the position inside the ring and the other of the input cone and the output cone is located at the inside of the ring. The ring is disposed outside the ring, and the cross-sectional shape of the ring is formed so that the surfaces contacting the input cone and the output cone are respectively convex smooth curves, and the ring is sandwiched between the input cone and the output cone. Pressure to cause the rotational torque of the input cone to be frictionally transmitted to the output cone via the ring, and the ring guide mechanism is divided into two parts by a geometric plane including the rotation axes of the input cone and the output cone. The ring is installed in the space on the front side of the clamping section where the ring is clamped by the input cone and the output cone, and the ring is guided by the ring guide mechanism. Because you have to shift by moving in the axial longitudinal direction of the auxiliary output cone, lightweight, efficient, can be obtained with a continuously variable transmission can simultaneously satisfy improvement in durability.

The continuously variable transmission according to the present invention comprises a plurality of units, one of the input cone and the output cone, a ring, and a ring guide mechanism. When the other of the output cones is configured as one, the number of rotation transmission points can be increased and high load transmission can be achieved, and when a plurality of these units are arranged at equal intervals, the output cone becomes narrower. The pressing force acting on the pressure portion is symmetrical with respect to the axis of the input cone or the output cone, so that the structural design of the machine frame receiving the reaction force can be easily performed, and the weight can be reduced.
In the ring guide mechanism as described in the above, the ring guide is constrained in a geometric plane perpendicular to the direction of speed change movement of the ring guide, and the ring guide is rotatable at a position for guiding the ring in the geometric plane. With the supported configuration, a simple continuously variable transmission having a small number of parts can be formed, and the ring can be moved with a small force, and the ring guide mechanism can be reduced in size and weight. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of a configuration of a continuously variable transmission according to the present invention.

FIG. 2 is a view taken in the direction of the arrow II in FIG. 1;

FIG. 3 is a schematic view showing one embodiment of a cross-sectional shape of a ring.

FIG. 4 is a schematic perspective view showing one embodiment of a configuration of a ring guide mechanism.

FIG. 5 is a schematic sectional view showing a second embodiment of the configuration of the continuously variable transmission according to the present invention.

6 is a view taken in the direction of arrows II-II in FIG. 5;

FIG. 7 is a schematic sectional view showing one embodiment of a configuration of a conventional continuously variable transmission.

FIG. 8 is a view taken in the direction of arrows III-III in FIG. 7;

[Explanation of symbols]

 1,31 Machine frame 2,32 Input shaft 4,34 Input cone 5,36 First output cone 7,40 First ring 8,41 Second output cone 10,45 Second ring 11,47 Output shaft 13,14, 15, 50, 51, 52 Gear 16, 54, 55 Ring narrowing mechanism 17, 18, 56, 57, 58 Ring guide mechanism 19 Ball screw shaft 20 Ball screw nut 21 Bracket 22 Arm member 23 Spherical guide 38, 43 Shaft 46 Third output cone 47 Third ring 34a Gear

Claims (3)

[Claims] 1. A transmission comprising: an input cone for rotation input; an output cone for rotation output; a ring for rotation transmission; and a ring guide mechanism for moving the ring along each of the cones. Either the input cone or the output cone is disposed at the inner position of the ring, and the other of the input cone or the output cone is disposed at the outer position of the ring. The surfaces in contact with the output cone are formed so that each has a smooth convex curve, and the ring is pressed between the input cone and the output cone so that the rotational torque of the input cone is transmitted to the output cone via the ring. In addition, the ring guide mechanism is divided into two parts by a geometric plane including the rotation axes of the input cone and the output cone.
The ring is installed in a space on the front side of a clamping portion that is clamped by the input cone and the output cone, and the ring is moved by the ring guide mechanism in the longitudinal direction of the axis of the input cone and the output cone to change the speed. A continuously variable transmission characterized in that: 2. The method according to claim 1, wherein one of the input cone or the output cone, the ring, and the ring guide mechanism are formed as a plurality of units, and the other of the input cone or the output cone is formed as a single unit. Claim 1
Continuously variable transmission. 3. The ring guide mechanism, wherein the ring guide is constrained in a geometric plane perpendicular to the speed-change movement direction of the ring guide, and the ring guide is rotatable at a position for guiding the ring in the geometric plane. 3. The continuously variable transmission according to claim 1, wherein the continuously variable transmission has a supported structure.