JP2654187B2 - Continuously variable transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a continuously variable transmission, and more particularly, to a frictionless continuously variable transmission having a tapered cone.

[Conventional technology]

Conventionally, as the continuously variable transmission, for example,
There was one disclosed in Japanese Patent No. 270858. That is, the tapered cone rotates following the inner surface of the ring-shaped transmission member, and the rotational force of the tapered cone is taken out from the output rotating body geared to one end of the tapered cone.

[Problems to be solved by the invention]

Conventionally, since the rotational force of the taper cone is transmitted to the output rotating body via a gear, the structure of the gear transmission system tends to be complicated, and there is room for improvement.

It is conceivable to simplify the structure by contacting the taper cone with the rotating body and transmitting power by frictional force.However, simply contacting makes it easy for slip to occur when the load increases. Was.

An object of the present invention is to provide a continuously variable transmission that can be advantageously obtained in terms of structure, assembly, and transmission.

[Means for solving the problem]

A feature of the continuously variable transmission according to the present invention is that the small diameter side of the tapered cone is freely rotatably and integrally supported on a carrier to which rotational power around the shaft is transmitted, and the free rotating shaft of the tapered cone is attached to the carrier. The carrier is engaged with the holding portion that engages and supports the taper cone in a state where the taper cone is allowed to move relative to the carrier in the direction of swinging and sliding, and the carrier contacts the outer peripheral portion on the small diameter side of the taper cone. A support member that supports the tapered cone, a rotary member that frictionally transmits the tapered cone with the tapered cone at the contact portion by pressing against a surface in a direction intersecting the conical surface on the large diameter side of the tapered cone, and a state of contacting the conical surface of the tapered cone; A ring-shaped speed change member that moves along the axis to set a speed change rate between the carrier and the rotating body to an arbitrary value. A transmission member that is located on the same axis as the rotating body on the opposite side to the tapered cone and that is linked to the output unit, the transmission member being in contact with a cam surface formed on at least one of the transmitting member and the rotating body. An automatic pressure adjusting mechanism is provided for holding the ball between the rotating body and the contact pressure of the rotating body against the tapered cone as the load increases. And a continuously variable transmission system that changes the speed of the rotating body and outputs the rotating body via the transmission member, and in the non-transmission state, the urging force from the urging means for generating pressure to contact the rotating body with the tapered cone. The point is that it acts on the transmission member. Its action,
And the effect is as follows.

[Operation] The carrier rotates due to the introduced rotational force to orbit the taper cone around the rotation axis of the carrier, and the taper cone rotates due to friction with the transmission member. Then, the rotation force of the taper cone is transmitted to the rotating body by friction, and the rotating force of the rotating body is transmitted to the transmission member via the ball of the automatic pressure adjusting mechanism. When the speed change member is moved, the speed ratio between the carrier and the rotator changes, and the rotation speed of the rotator changes, so that the rotation speed of the transmission member changes. This makes it possible to take out a rotational force whose rotational speed changes steplessly with the transmission member as the output side.

Even if the load on the transmission destination increases, the automatic pressure adjusting mechanism increases the frictional force between the rotation body and the taper cone due to the transmission member, the cam surface of the surface of the rotation body, and the ball. As a result, even when the load is high, slippage between the rotating body and the tapered cone hardly occurs, and power is transmitted reliably. Since the frictional force between the rotating body and the tapered cone increases in proportion to the magnitude of the load, the pressure contact force between the rotating body and the tapered cone becomes relatively weak during non-transmission.

Since the urging force from the urging means acts on the transmission member even in the non-transmission state, the cam surface and the ball are in contact with each other even at the time of starting, and the automatic pressure adjusting mechanism functions.

That is, when the rotating body and the taper cone are always brought into contact with each other with a constant urging force so that no slip occurs even under a high load, the urging force increases even at a low load such as at the time of starting. On the other hand, in the case of the present invention, the power can be transmitted without causing a slip by causing the tapered cone and the rotating body to come into contact with an appropriate pressure regardless of the magnitude of the load.

The support member contacts the small diameter side of the taper cone, the transmission member contacts the conical surface of the taper cone, and the rotating body contacts the surface that intersects the conical surface of the taper cone. The three members support the tapered cone in a stable posture such that it smoothly revolves and rotates. Thereby, a simple structure in which the carrier engages and supports the structure for supporting the tapered cone by the holding portion, that is, only that the carrier and the tapered cone rotate integrally around the rotation axis of the carrier and that the tapered cone rotates on its own. Power can be transmitted as desired without causing a power loss due to slippage such as frictional transmission.

Further, since the carrier engages and supports the tapered cone with the holding portion, and the tapered cone can swing or slide with respect to the carrier, the support member, the speed change member, and the rotating body When the assembling is performed so as to make contact with the tapered cone as desired, the tapered cone moves freely with respect to the carrier due to the contact reaction force of the support member, the speed change member, and the rotating body, so that a stable assembling posture is achieved.
In other words, no twisting occurs in the connecting portion between the carrier and the tapered cone, and the assembly state in which the support member, the speed change member, and the rotating body contact the tapered cone as desired and each member operates smoothly as desired is naturally obtained.

In addition, by adopting a configuration in which the carrier engages and supports the taper cone, slip generation in this portion can be avoided as compared with, for example, a configuration in which the transmission from the carrier to the taper cone is friction transmission. It is useful for further improving efficiency.

〔The invention's effect〕

Therefore, since the transmission between the taper cone and the rotating body can be transmitted by a simple transmission structure by friction, the carrier can support the taper cone by the simple engagement support. The transmission structure with less noise can be obtained.

In addition, the frictional force between the taper cone and the rotating body can be increased or decreased according to the load by the action of the automatic pressure adjustment mechanism. This is advantageous in that power can be suppressed and transmitted reliably, and friction can be reduced when power is not transmitted or when the load is low, and durability can be improved compared to the case where a large friction force is constantly applied. It is.

Furthermore, as the support member, the speed change member and the rotating body come into contact with the tapered cone, the tapered cone becomes stable to the carrier and becomes self-attaching without any twisting. Since the pressing force can be reduced, the assembling work can be efficiently and easily performed as a whole.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 1, a case (1) is provided with a main shaft (3) whose both ends are supported via bearings (2) and (2), and an input gear is provided for the main shaft (3). (4) supports the carrier (5) formed integrally with the carrier (5), and the support shaft (6) is engaged with and supported by the holding portions (5a) formed on the carrier (5). , A disk-shaped rotating body (8) that comes into contact with the large-diameter side of these tapered cones (7) and is slidable along the axis (P) of the main shaft (3); An automatic pressure adjusting mechanism (A) for adjusting the contact pressure between the rotating body (8) and the taper cone (7) is provided on the same axis as the main shaft (3). ) Is arranged so as to be adjustable along a rod (9) parallel to the taper cone (7). A ring-shaped transmission member (10) and a tapered cone (7) having a protruding edge (11a) in contact with an annular recess (7a) formed on each of the small diameter sides, and freely rotating on the main shaft (3). A friction type continuously variable transmission is provided by providing a supporting member (11) for supporting and a sprocket (12) for extracting power from the main shaft (3).

Further, in this transmission, a needle bearing (13) is disposed between the carrier (5) at the portion where the input gear (4) is formed and the main shaft (3), and the support shaft (6) and the taper cone (7) are arranged. ) And a needle bearing (15) ...
Between the support member (11) and the main shaft (3), the support member (1
A needle bearing (16) and a thrust bearing (17) are arranged between 1) and the carrier (5), respectively, and the automatic pressure regulating mechanism (A) is arranged as shown in FIGS. 1 and 5. A transmission member (18) that is slidably movable along the axis (P) and that is capable of transmitting torque to the main shaft (3), and a plurality of cams formed on the transmission member (18). Surface (18a) and sleeve part (8s) of rotating body (8)
Ball (19) sandwiched between a plurality of cam surfaces (18a) formed in the above, and a compression coil spring (20) for setting an initial pressure
When the load is small, the automatic pressure adjusting mechanism (A) moves the balls (19)... At the bottom of the cam surfaces (18a) and (8a) by the urging force of the coil spring (20). As a result of maintaining a stable state, a low pressure contact force is applied between the rotating body (8) and the tapered cone (7), and when the load increases, the rotating body (8 ) And the transmission member (18) have a larger rotational phase difference, and as shown in FIG. 5, the balls (19)... Move more in relation to the cam surfaces (18a) and (8a) in proportion to the load value. As a result,
Appropriate pressing force corresponding to the value of the load is applied between the rotating body (8) and the tapered cone (7) to suppress a slip between the rotating body (8) and the tapered cone (7). I have.

This coil spring (20) is an example of a biasing means,
This coil spring (20) consists of a transmission member (18) and a ball (19)
They are arranged at positions where pressure is applied to the rotating body (8) via each of them.

Further, a fork (22) connected to the operation shaft (21) is engaged with the sleeve portion (8s) of the rotating body (8), and even during transmission, the fork (22) is rotated by pulling the operation shaft (21). The contact between the body (8) and the tapered cone (7) is released to shut off the power.

As shown in FIG. 4, flat surfaces (6a) are formed at both ends of the support shaft (6) so as to contact the holding portions (5a) with a wide surface. Thus, the carrier (5) engages and supports the small diameter side of the tapered cone (7) by the holding portion (5a). The engagement of the holding portion (5a) with the flat surface (6a) enables the carrier (5) to rotate integrally with the taper cone (7) around the axis (P), and the play of the taper cone (7). The taper cone (7) is allowed to move with respect to the carrier (5) in a direction in which the rotation axis swings and slides with respect to the carrier (5).

In this transmission, in the state where power is transmitted to the input gear (4), when the transmission member (10) is operated in the transmission operation range (S), the transmission member (10) is brought into contact with the transmission member (10). Since the radius of the taper cone (7) from the rotation axis changes, that is, the circumferential length of the taper cone (7) at the position where the transmission member (10) contacts changes, the carrier (5) is used as a unit. When rotated by an amount, the amount of rotation of the tapered cone (7) that rotates following the inner surface of the transmission member (10) changes,
The rotation speed of the rotating body (8) to which power is transmitted from the taper cone (7) changes with respect to the rotation speed of the carrier (5). As a result, the sprocket (12) arranged in parallel with the input gear (4) continuously changes the rotation speed. The power that has been shifted is taken out.

Further, in this transmission, as shown in FIG. 2, the contact pressure of the rotating body (8) on the taper cone (7) is (F ₁ ), and the contact pressure of the transmission member (10) on the taper cone (7) is (F _2). ), The support members (1
The contact position of the taper cone (7) of 1) is set to
The contact pressure (F ₁ ), (F ₂ ) is set at a position where the moment acting on the taper cone (7) due to the _two contact pressures can be canceled out, so the taper cone (7) of the support member (11)
When the contact pressure with respect to is determined as (F ₃ ) and one of the holding portions (5a) is determined as the center, F ₁ × l ₁ + F ₃ × l ₃ −F ₂ × l ₂ = 0 holds and the moment The balance is maintained, and the vectors (F ₁ ), (F ₂ ) and (F ₃ ) are closed as shown in FIG.

Incidentally, in this transmission, the projecting edge (11a) of the support member (11) is fitted into the annular concave portion (7a) of the tapered cone (7). Therefore, when the position of the transmission member (10) is changed, At the same time as the attitude of the tapered cone (7) slightly changes, the pressing direction of the protruding edge (11a) against the annular recess (7a) changes in the direction in which the moment is balanced, and reaches a stable state in a very short time. When the contact pressure between the rotating body (8) and the tapered cone (7) changes, such as when the load changes, a pressure proportional to this contact pressure is applied from the support member (11) to the tapered cone (7). As they act, the moment balance is maintained.

(Another embodiment)

The present invention can be implemented in various ways other than the above-described embodiment, for example, the biasing unit is configured as a tension spring or a disc spring.
Further, the continuously variable transmission can be used in various fields such as being used for a self-propelled vehicle body, such as being provided in a traveling transmission system of an agricultural work vehicle, and used for a machine tool.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the structure shown in the attached drawings.

[Brief description of the drawings]

The drawings show an embodiment of the continuously variable transmission according to the present invention, and FIG.
FIG. 2 is a cross-sectional view of the device, FIG. 2 is a diagram showing a force acting on a taper cone, FIG. 3 is a diagram showing a vector, FIG. 4 is a diagram showing a holding portion, and FIG. FIG. (5) ... Carrier, (5a) ... holding part, (7) ... taper cone, (8) ... rotating body, (10) ... shifting member,
(11) ... support member, (12) ... output section, (18) ... transmission member, (19) ... ball, (20) ... urging means,
(A): Automatic pressure adjusting mechanism, (P): Shaft core.

Claims (1)

(57) [Claims] A small diameter side of a tapered cone (7) is supported on a carrier (5) to which rotational power about a shaft core (P) is transmitted so as to freely rotate and integrally rotate, and the taper cone (7) rotates freely. The carrier (5) is mounted on the taper cone (7) in a state where the taper cone (7) is allowed to move relative to the carrier (5) in a direction in which a shaft core swings and slides with respect to the carrier (5). And a support member (1) that supports the tapered cone (7) by contacting the outer peripheral portion on the smaller diameter side of the tapered cone (7).
1) a rotating body (8) that comes into pressure contact with a surface in a direction intersecting the conical surface on the large diameter side of the tapered cone (7) and frictionally transmits the tapered cone (7) at the contact portion; The carrier (5) and the rotating body (8) move along the axis (P) in contact with the conical surface of
A ring-shaped transmission member (10) for setting a transmission rate between the rotation member and the rotation member to an arbitrary value, and a coaxial core with the rotation member (8) on the opposite side of the taper cone (7) with respect to the rotation member (8). A transmission member (18) which is located above and is interlocked with the output portion (12),
The transmission member (18) is in contact with a cam surface formed on at least one of the transmission member (18) and the rotating body (8).
An automatic pressure adjusting mechanism (A) for sandwiching a ball (19) between the rotating body (8) and the rotating body (8) to increase the contact pressure of the rotating body (8) with respect to the tapered cone (7) as the load increases. )
And a rotational force is introduced into the carrier (5) to change the input rotation so that the transmission member (1) is moved from the rotating body (8).
8) constitutes a continuously variable transmission system that outputs
A continuously variable transmission, wherein an urging force from an urging means (20) for generating pressure for bringing the rotating body (8) into contact with the tapered cone (7) in a non-transmission state is applied to the transmission member (18).