JP2009222165A - Continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve transmission efficiency, while miniaturizing a continuously variable transmission. <P>SOLUTION: This continuously variable transmission has an input shaft 20 rotatably supported around the predetermined axis to a housing, a shift unit U for continuously variably shifting rotation of the input shaft by traction force, an output shaft 120 rotatably supported by the housing, and a loading cam mechanism 110 interposed between the shift unit and the output shaft and generating a pressing load in the axial direction, and a speed increasing mechanism 90 is arranged between the input shaft and the shift unit, for increasing and transmitting a rotating speed of the input shaft to the shift unit. Thus, since the rotating speed of the input shaft is increased by the speed increasing mechanism and is transmitted to the shift unit, transmission torque by the traction forced is reduced by a speed increase quantity, and a rate of a thrust load by the loading cam mechanism can be reduced to transmission output, and a loss of a bearing for supporting the input shaft can be reduced, and the transmission efficiency can be particularly improved in a small area of the gear ratio. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a continuously variable transmission that continuously changes the rotational speed of an input shaft and transmits it to an output shaft by a traction drive that uses a traction force. The present invention relates to a continuously variable transmission that performs step shifting.

As a conventional continuously variable transmission, as shown in FIG. 6, an input shaft 3 and an output which are rotatably supported via flange bearings 1 a connected to both sides of a cylindrical housing 1 via angular bearings 2. The shaft 4, a frustoconical sun roller (inner ring) 5 connected by a key 3 a so as to rotate integrally with the input shaft 3, and a holder (rotatably supported by the input shaft 3 via a bearing 3 b ( Cage) 6, a plurality of taper rollers (planetary rollers) 7 that are rotatably supported by the holder 6 and roll on the outer peripheral surface of the sun roller 5, an output ring that rotates integrally with the output shaft 4 and circumscribes the taper roller 7. (Driving outer ring) 8, which is provided with a transmission ring (rotating fixed outer ring) 9 which circumscribes a conical portion 7a provided integrally with the taper roller 7 and which is reciprocated only in the generatrix direction of the conical portion 7a is known. The That (for example, see Patent Document 1).
In this continuously variable transmission, when the input shaft 3 rotates, the sun roller 5 rotates integrally, the taper roller 7 circumscribing the sun roller 5 rotates and revolves, and the output ring 8 rotates due to the rotation of the taper roller 7. The output shaft 4 rotates together with the output shaft 4, and the rotational speed of the output shaft 4 is increased or decreased according to the position of the transmission ring 9.

However, in this continuously variable transmission, the normal load on the contact surface between the taper roller (planetary roller) 7 and the sun roller 5, the normal load on the contact surface between the taper roller 7 and the output ring 8, and the conical portion 7 a of the taper roller 7. The normal load on the contact surface of the transmission ring 9 depends on the initial assembly accuracy, and since there is no means for correcting fluctuations in the normal load due to changes over time, the necessary traction force cannot be obtained. There is a risk that the shifting operation may not be performed reliably. In particular, since the tapered roller 7 is supported in a cantilever manner by the holder 5, the conical portion 7 a side of the tapered roller 7 is easily bent, and it is difficult to increase the contact pressure with the transmission ring 9.
Along with the increase of the normal load, a thrust load is generated in the axial direction of the input shaft 3 and the output shaft 4, and this thrust load is received by the bearing 2 or the housing 1 of the input shaft 3 and the output shaft 4. Therefore, the angular bearing 2 and the housing 1 may be deformed over time or the lubricating oil temperature may be increased due to heat generation in the bearing region, which may cause wear and decrease in power transmission efficiency. On the other hand, if the rigidity of the housing 1 is increased in order to cope with deformation and the like, an increase in size or weight will be caused.

As another continuously variable transmission, an input shaft rotatably supported by a casing via a bearing, a sun roller that rotates integrally with the input shaft, a contact with the sun roller, and a reciprocating motion in the axial direction of the input shaft A double cone, an outer ring that contacts the double cone from the outside and rotates around the input shaft, a planetary gear that meshes with a sun gear sun gear provided on the input shaft, a ring gear that meshes with the planetary gear, a clutch drum that holds the ring gear, A cam disk that rotates integrally with the clutch drum, a loading cam mechanism that generates an axial pressing force interposed between the outer ring and the cam disk, a clutch mechanism provided in the clutch drum, and a bearing on the casing The transmission of the driving force is turned on / off by switching the clutch mechanism. Those with an output shaft or the like which is is known (e.g., see Patent Document 2).
In this continuously variable transmission, since a loading cam mechanism is provided, it is possible to adjust the fluctuation of the traction force (normal load) in the region of the traction transmission unit as compared with the continuously variable transmission described above. it can.

However, in the continuously variable transmission having a configuration that secures a normal load in the region of the traction transmission unit by providing a loading cam mechanism on the output shaft side and generating a thrust load in this manner, The thrust load increases in proportion to the magnitude (in the axial direction of the input shaft). In particular, the output torque increases in a region where the gear ratio is small, and the thrust load is also very large.
Therefore, although bearings (angular bearings, thrust bearings, etc.) are provided on the input shaft and the output shaft to receive a large thrust load, transmission force loss occurs in the bearings. As shown in FIG. 7, the loss (decrease in transmission efficiency) is slight and constant in the output side bearing, but in the input side bearing, the low speed range (for example, the gear ratio) with a large torque is obtained. This is remarkable in a region where i is 0.05 or less.
That is, with respect to the input side bearing, the load applied to the bearing increases as the rotational speed is constant and the speed ratio i is smaller, so that the amount of work to be lost increases. On the other hand, with respect to the output side bearing, The smaller the gear ratio is, the larger the load applied to the bearing is. However, since the rotational speed is smaller in proportion to the gear ratio, the loss of work is offset and becomes a constant value. Therefore, in particular, in order to increase the torque transmission efficiency in the entire speed ratio, it is necessary to reduce the loss (bearing loss) in the bearing on the input side.

JP-A-6-280961 JP 2003-227559 A

  The present invention has been made in view of the circumstances of the above-described conventional apparatus, and its object is to simplify the structure, reduce the size, reduce the cost, improve the functional reliability, and the like. Continuously variable transmission that ensures sufficient traction force or transmission torque, reduces bearing loss and improves transmission efficiency, and can stably shift to a desired gear ratio. To provide an apparatus.

The continuously variable transmission according to the present invention includes an input shaft that is rotatably supported about a predetermined axis with respect to a housing, a transmission unit that continuously changes the rotation of the input shaft by a traction force, and a housing that is freely rotatable. A continuously variable transmission comprising: an output shaft supported on the transmission shaft; and a loading cam mechanism that is interposed between the transmission unit and the output shaft and generates a pressing load in an axial direction. The speed increasing mechanism for increasing the rotational speed of the input shaft and transmitting it to the transmission unit is provided.
According to this configuration, the rotational speed of the input shaft is increased through the speed increasing mechanism, and is continuously shifted by the speed change unit. The changed rotational speed is output from the output shaft via the loading cam mechanism.
Here, since the rotational speed of the input shaft is increased by the speed increasing mechanism and transmitted to the speed change unit, the transmission torque due to the traction force is reduced by the increased speed, and the ratio of the axial thrust load generated by the loading cam mechanism Can be reduced with respect to the transmission output (output torque), and therefore the loss of the bearing supporting the input shaft (bearing loss) can be reduced, and the transmission efficiency is improved especially in the region where the gear ratio is small. Can be made. Further, since the rotational speed of the input shaft is increased by the speed increasing mechanism, the transmission output (output torque) is also improved by the speed increase, and the transmission output can be improved as a whole.

In the above configuration, the transmission unit includes a truncated cone-shaped sun roller that is accelerated by the speed increasing mechanism and rotates around the axis, a plurality of planetary rollers that roll on the outer peripheral surface of the sun roller, and the planetary roller that is inscribed and rotated. Shifting provided in a movable manner in the axial direction so that the output ring provided movably and the conical part formed integrally with the planetary roller can be inscribed in a freely rolling manner and the inscribed position is moved to change the speed. Configurations including rings can be employed.
According to this configuration, the rotational driving force transmitted from the input shaft through the speed increasing mechanism is transmitted to the output shaft through the sun roller → the plurality of planetary rollers → the output ring → the loading cam mechanism, and the transmission ring By appropriately moving the position in the axial direction, it is possible to change the speed steplessly and to output the rotational driving force changed from the output shaft.

In the above configuration, the speed increasing mechanism rolls on the input roller that can rotate integrally with the sun roller, the inner peripheral surface of the fixed cylindrical portion formed on the housing so as to be coaxial with the axis, and the outer peripheral surface of the input roller. A configuration including a plurality of revolving rollers connected to the input shaft to revolve around the axis can be employed.
According to this configuration, when the input shaft rotates, the plurality of revolving rollers roll on the inner peripheral surface of the fixed cylindrical portion while revolving around the axis, and the revolving and revolving (rotating) rotation of the revolving roller causes the input roller ( And the sun roller) are rotated at an increased speed.
As described above, by employing the traction planetary mechanism that transmits the driving force using the traction force as the speed increasing mechanism, the speed can be increased smoothly.

In the above-described configuration, the speed increasing mechanism can employ a configuration that is formed to receive an axial load applied toward the input shaft in the traction planetary mechanism as described above.
According to this configuration, since the speed increasing mechanism receives not only a radial load but also a thrust load in the axial direction in the area of the input shaft, the conventional angular bearing can be eliminated, and the loading cam mechanism By receiving the thrust load that increases in proportion to the output torque due to the action of the torque with the speed increasing mechanism and collecting it as the normal load required for traction transmission for speed increasing, the loss is reduced and the entire transmission is transmitted. Efficiency can be improved.

In the above configuration, it is possible to employ a configuration including a trigger mechanism that turns on / off the transmission of the rotational force by the traction force between the sun roller and the planetary roller according to the rotational speed of the input shaft.
According to this configuration, the sun roller and the planetary roller are not always directly connected (in close contact with each other so as to generate traction force), but when the rotation speed of the input shaft (sun roller) increases, the trigger mechanism is turned on and the sun roller Since the rotational driving force of the (input shaft) is transmitted to the planetary roller via the traction force, the rotation of the sun roller, that is, the input shaft can be interlocked with the output shaft at a desired timing, while the input shaft (sun roller) When the rotational speed decreases, the trigger mechanism is turned off and the rotational driving force of the sun roller (input shaft) is not transmitted to the planetary roller, so the output shaft is free regardless of the rotation of the input shaft (sun roller) (can be rotated by external force) Can be.

In the above configuration, the trigger mechanism changes a pressing load in the axial direction in accordance with the centrifugal force around the axis, and a configuration arranged between the input roller and the sun roller can be adopted.
According to this configuration, since the trigger mechanism is configured to turn on / off the transmission of the rotational force in the acceleration state after the rotation speed of the input shaft is increased by the acceleration mechanism, the rotation of the input shaft Compared to the case where the speed is directly received, a centrifugal force N times proportional to the square of the rotational speed can be obtained, and therefore the mass of the weight or the like that receives the centrifugal force can be reduced to 1 / N times.

In the above configuration, the input roller has a shaft portion centered on the axis, and the sun roller is connected to the shaft portion so as to rotate integrally and move in the axial direction. Can do.
According to this configuration, since the sun roller is configured to rotate integrally around the axis while being able to move relative to the input roller in the axial direction, the axial direction using the centrifugal force of the trigger mechanism By increasing or decreasing the load, it is possible to reliably control the contact pressure (load for turning on / off the transmission of rotational force) between the sun roller and the plurality of planetary rollers.

In the above configuration, it is possible to adopt a configuration including an annular movable holder that supports a plurality of planetary rollers so as to be capable of rotating and revolving around an axis, and the speed increasing mechanism is disposed in an inner region of the movable holder. it can.
According to this configuration, it is possible to arrange the speed increasing mechanism by effectively using the space while achieving the integration of parts, and it is possible to reduce the size of the entire apparatus.

In the above-described configuration, an annular movable holder that supports a plurality of planetary rollers so as to be capable of rotating and revolving around an axis is provided, the sun roller has a cylindrical portion centered on the axis, and the movable holder is a fixed cylinder of the housing. The structure which is rotatably supported by the cylindrical part of the part and the sun roller can be adopted.
According to this configuration, the movable holder is rotatably supported around the axis by the fixed cylindrical portion of the housing and the cylindrical portion of the sun roller on the outside of the speed increasing mechanism, and a plurality of planetary rollers are formed by the rotation of the movable holder. Revolve around the axis. Thus, by arranging the speed increasing mechanism and the speed change unit (movable holder, sun roller, and a plurality of planetary rollers) on the same axis (on the axis), it is possible to achieve integration and downsizing of the entire apparatus.

  According to the continuously variable transmission configured as described above, the structure is simplified, reduced in size, reduced in cost, improved in functional reliability, etc., and sufficient traction force or transmission torque is ensured. Loss (bearing loss) can be reduced, transmission efficiency can be improved, and a continuously variable transmission that can stably shift to a desired gear ratio can be obtained.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.
1 to 5 show an embodiment of a continuously variable transmission according to the present invention. FIG. 1 is a partial sectional view showing the inside of the device, FIG. 2 is a sectional view showing the inside of the device, and FIG. Is a cross-sectional view showing a part of the apparatus, FIG. 4 is a schematic view showing the outline of the apparatus, and FIG. 5 is a schematic view showing a loading cam mechanism forming a part of the apparatus.

As shown in FIGS. 1 and 2, the continuously variable transmission includes a housing 10, an input shaft 20, a transmission unit U, a speed increasing mechanism 90, a trigger mechanism 100, a loading cam mechanism 110, an output shaft 120, and the like. .
As shown in FIGS. 1 and 2, the transmission unit U has a sun roller 30 formed in a truncated cone shape, a plurality of planetary rollers 40 rolling around the sun roller 30, and rotating the planetary roller 40 inwardly. A freely supported output ring 50 and planetary roller 40 are inscribed in a freely rolling manner, and a transmission ring 60 for changing speed by moving the inscribed position, a driving mechanism 70 for driving the transmission ring 60, and the planetary roller 40 are rotated. A movable holder 80 or the like that supports the revolving around the axis L is possible.

As shown in FIG. 2, the housing 10 includes a housing body 11, a flange wall portion 12 connected to the housing body 11, a radial bearing 13 and ring seal 14 that support the input shaft 20, and an angular bearing 15 that supports the output shaft 120. And a ring seal 16, a connecting guide rod 17 that connects the flange wall 12 to the housing body 11, a fixed cylindrical portion 18 that protrudes inward from the flange wall 12 and that is formed around the axis L, and the like.
In the housing 10, lubricating oil supplied to a contact interface where the traction force of the transmission unit U is generated, other sliding surfaces, rolling surfaces, and the like is injected.

  As shown in FIGS. 2 and 3A, the input shaft 20 is rotatably supported by a reduced diameter shaft portion 21 that protrudes to the outside of the housing 10 and a radial bearing 13 that is fitted to the housing 10. A speed increasing mechanism 90, which is formed on the end face of the diameter portion 22 and the diameter increasing portion 22, is formed to protrude from the diameter expanding portion 22, and is formed to protrude from the diameter increasing portion 22, a support portion 23 that rotatably supports a revolving roller 92 of the speed increasing mechanism 90 described later. The holding portion 93 for fixing the holding ring 93 is provided.

As shown in FIG. 2, the sun roller 30 is formed in a substantially truncated cone shape and forms a part of a conical surface on which the planetary roller 40 rolls, and is formed on the input shaft 20 side after the outer peripheral surface 31. A skirt portion 32, a cylindrical portion 33 formed on the output shaft 120 side with a diameter smaller than that of the outer peripheral surface 31, a through hole 34 formed on the axis L, and the like.
The skirt portion 32 is formed so as to accommodate a part of the trigger mechanism 100 therein.
The cylindrical portion 33 is formed so as to rotatably support the movable holder 80 on the outer peripheral surface thereof and to accommodate a part of the trigger mechanism 100 on the inner side thereof.
As shown in FIG. 2, the through hole 34 is formed so that a shaft portion 91 c of an input roller 91 to be described later is fitted to be movable in the direction of the axis L and to rotate integrally around the axis L.

  As shown in FIGS. 1 and 2, the planetary roller 40 is circumscribed with the sun roller 30 (the outer peripheral surface 31) and also in contact with the output ring 50 (the inner peripheral surface 51). A second conical portion 42 that rolls in contact with the transmission ring 60 (inner peripheral surface 61), a first conical portion 41, a shaft portion 43 that passes through the rotation center of the second conical portion 42, and the like are provided.

As shown in FIG. 4, the first conical portion 41 is formed so as to taper toward the vertex A1 on the axis L, and is formed on the sun roller 30 (the outer peripheral surface 31) and the output ring 50 (the inner peripheral surface 51). It is touching so that it is pinched.
As shown in FIG. 4, the second conical portion 42 is formed to taper in the reverse direction (on the opposite side to the apex A1) following the first conical portion 41, and is formed on the transmission ring 60 (the inner peripheral surface 61 thereof). In contact.
As shown in FIG. 2, the shaft portion 43 is rotatably supported at both ends by a movable holder 80 so that both ends can move slightly.

Here, as shown in FIG. 4, the second conical portion 42 in all the planetary rollers 40 is a generatrix (the ridgeline with which the inner peripheral surface 61 of the transmission ring 60 contacts) at a position furthest away from the axis L in the radial direction. M2 is formed to extend in parallel with the axis L (the axis of the input shaft 20).
Further, the relationship between the planetary roller 40 and the transmission ring 60 will be further described. As shown in FIG. 4, the transmission ring 60 is located at a point Pn where the generatrix M1 defining the first conical portion 41 intersects the second conical portion 42. When the inner peripheral surface 61 is located, the planetary roller 40 rolls with respect to the output ring 50 and corresponds to the neutral position N where the output ring 50 is stopped.
Therefore, when the transmission ring 60 moves from the neutral position N to the left side in FIG. 4 (smaller diameter side of the second conical portion 42 as shown by the arrow D), the output ring 50 is continuously accelerated. To the top position. On the other hand, when the transmission ring 60 moves from the neutral position N to the right side (the larger diameter side of the second conical portion 42 as shown by the arrow R) in FIG. 4, the output ring 50 rotates in the reverse direction. It has become.

  2 and 4, the output ring 50 includes an inner peripheral surface 51 on which the first conical portion 41 of the planetary roller 40 is inscribed and rolls, and a first cam rotating plate 111 of the loading cam mechanism 110 described later. An annular end surface portion 52 and the like to be connected are provided. The output ring 50 rotates around the axis L by the traction force of the planetary roller 40 rotating and revolving, and rotates the output shaft 120 via the loading cam mechanism 110. Therefore, by increasing the normal force on the inner peripheral surface 51, a larger traction force is obtained, and the rotational force is reliably transmitted to the output shaft 120.

As shown in FIGS. 1 and 2, the transmission ring 60 includes an inner peripheral surface 61 that defines a cylindrical surface that is coaxial with the axis L so as to contact the second conical portion 42 of the planetary roller 40, and a part of the drive mechanism 70. And a guided portion 63 that is externally fitted to the connecting guide rod 17 and guided in the direction of the axis L.
The transmission ring 60 is supported in the housing 10 so as to reciprocate within a predetermined movement range in the direction of the axis L (input shaft 20) while being held in a non-rotatable manner around the axis L (input shaft 20). ing.

As shown in FIG. 2, the drive mechanism 70 is disposed in the housing 10 so as to extend in parallel with the axis L (the input shaft 20 and the output shaft 120), and is a lead that is screwed into the female screw portion 62 of the transmission ring 60. A screw 71, a drive motor 72 that is connected to one end of the lead screw 71 and exerts a rotational driving force are provided.
When the drive motor 72 rotates in one direction, the transmission ring 60 is moved toward the left side (speed increasing side) in FIG. 4, while when the drive motor 72 rotates in the reverse direction, the transmission ring 60 is moved to FIG. It moves toward the right (deceleration->stop-> reverse side).
That is, by moving the speed change ring 60 in the direction of the axis L, the inscribed position where the second conical portion 42 of the planetary roller 40 is inscribed with the inner peripheral surface 61 is moved, thereby performing continuously variable transmission. ing.

Specifically, as shown in FIG. 4, when the transmission ring 60 is in contact at the neutral position N of the second conical portion 42, the planetary roller 40 rolls with respect to the output ring 50, and the output ring 50 Is stopped without rotating, that is, the output shaft 120 is also stopped.
Next, when the transmission ring 60 is moved to the left (toward the small-diameter end side of the second conical portion 42 as indicated by the arrow D in FIG. 4), the rotational speed of the output ring 50 is gradually increased. The output shaft 120 is also rotated at a higher speed. On the other hand, when the transmission ring 60 is moved to the right from the neutral position N (toward the large diameter end side of the second conical portion 42 as shown by the arrow R in FIG. 4), the output ring 50 is reversed. It is designed to rotate.

As shown in FIGS. 1 and 2, the movable holder 80 is formed in an annular frame structure (birdcage shape), and the fixed cylindrical portion 18 and the sun roller of the housing 10 so as not to contact other parts in the housing 10. 30 cylindrical portions 33 are held so as to be rotatable around an axis L via bearings.
As shown in FIGS. 2 and 4, the movable holder 80 moves a plurality of (here, six) planetary rollers 40 within a virtual conical surface having an apex A1 on the axis L (with respect to the axis L). It is formed so as to be able to rotate and revolve in a state of being arranged at equal intervals (with an axis S1 forming an angle θ1 as a rotation center axis).
Thus, since the movable holder 80 is rotatably supported by the fixed cylindrical portion 18 of the housing 10 and the cylindrical portion 33 of the sun roller 30 outside the speed increasing mechanism 90, the plurality of planetary rollers 40 have the axis L. The speed increasing mechanism 90 and the speed change unit U (the movable holder 80, the sun roller 30, and the plurality of planetary rollers 40) are arranged on the same axis (on the axis L). Centralization and miniaturization can be achieved.

  As shown in FIGS. 2 to 4, the speed increasing mechanism 90 includes an input roller 91 that can rotate integrally with the sun roller 30, an inner peripheral surface 18 a of the fixed cylindrical portion 18 formed on the housing 10, and an outer periphery of the input roller 91. A plurality (six in this case) of revolving rollers 92 connected to the input shaft 20 to roll around the surface 91a and revolve around the axis L, and the revolving rollers 92 are rotatably held and fixed to the input shaft 20 A retaining ring 93 and the like connected to the head 24 are provided.

As shown in FIGS. 3A, 3B, and 4, the input roller 91 includes a frustoconical outer peripheral surface 91a, a disc portion 91b that protrudes in a radial direction from the outer peripheral surface 91a, and a disc portion 91b. A shaft portion 91c that extends toward the output shaft 120 around the axis L is provided. That is, the input roller 91 can be rotated integrally with the sun roller 30 and can be moved relatively in the direction of the axis L.
In this way, the sun roller 30 is connected to the 91c shaft portion of the input roller 91 so as to rotate integrally and move in the direction of the axis L, that is, the sun roller 30 is connected to the axis L of the input roller 91. The sun roller 30 and the plurality of planets are increased by increasing or decreasing the load in the direction of the axis L using the centrifugal force of the trigger mechanism 100 because they rotate integrally around the axis L in a state where they can move relative to each other. Control of the contact pressure with the roller 40 (load for turning on / off the transmission of rotational force) can be reliably performed.
As shown in FIGS. 2 and 3A and 3B, the revolving roller 92 is formed so as to define a conical outer peripheral surface, and in a virtual conical surface having an apex A2 on the axis L. Are arranged at equal intervals (with an axis S2 forming an angle θ2 with respect to the axis L) as a rotation center axis, and are rotatably connected to the support portion 23 of the input shaft 20.
As shown in FIG. 2, the holding ring 93 is rotatably connected to the fixed portion 24 of the housing 10 while rotatably supporting the end portion of the revolving roller 92.

  When the input shaft 20 rotates at a predetermined rotational speed, the revolving roller 92 rolls on the inner peripheral surface 18a of the fixed cylindrical portion 18 while revolving around the axis L together with the input shaft 20, and the revolving roller 92 The input roller 91 is accelerated to a predetermined value by revolving and rolling (spinning). That is, the speed increasing mechanism 90 increases the rotational speed of the input shaft 20 and transmits it to the sun roller 30 of the transmission unit U. As described above, by employing the traction planetary mechanism that transmits the driving force using the traction force as the speed increasing mechanism, the speed can be increased smoothly.

Further, as shown in FIGS. 2 and 4, the speed increasing mechanism 90 is formed so as to receive a load in the direction of the axis L applied to the input shaft 20. Therefore, in the area of the input shaft 20, the speed increasing mechanism 90 receives not only a radial load but also a thrust load in the direction of the axis L, so that the conventional angular bearing can be eliminated. In addition, due to the action of the loading cam mechanism 110 described later, a thrust load that increases in proportion to the output torque is received by the speed increasing mechanism and recovered as a normal load necessary for traction transmission for speed increasing. And the transmission efficiency as a whole can be improved.
Further, since the speed increasing mechanism 90 is arranged in the inner region of the movable holder 80, it is possible to arrange the components while effectively consolidating the parts, and to achieve the downsizing of the entire apparatus. be able to.

The trigger mechanism 100 changes the pressing load in the direction of the axis L according to the centrifugal force around the axis L, and the sun roller 30 and the planetary roller 40 according to the rotational speed of the input shaft 20 (that is, the input roller 91). The transmission of the rotational force due to the traction force between the two is turned on / off.
That is, as shown in FIG. 2, the trigger mechanism 100 includes a plurality of spherical weights 101 arranged between the disc portion 91b of the input roller 91 and the skirt portion 32 of the sun roller 30, the inclined plate 102, and the inclined plate. A spring 103 that urges 102 toward the weight 101, a spring 104 and a spring that are disposed inside the cylindrical portion 33 and urge the sun roller 30 away from the planetary roller 40 (leftward in the direction of the axis L in FIG. 2). The receiving part 105 etc. which receive 104 are provided.

  Then, when the rotation speed of the input shaft 20 (the input roller 91 and the sun roller 30) is increased from the state in which the sun roller 30 and the planetary roller 40 idle with respect to each other (the state in which the traction force on the contact surface does not act), The weight 101 moves outward in the radial direction and presses the inclined plate 102 (to the right in the direction of the axis L in FIG. 2), thereby pressing the sun roller 30 to the right in the direction of the axis L through the spring 103 ( On). That is, the sun roller 30 is pressed so as to bite into the plurality of planetary rollers 40. As a result, a traction force is generated, and the rotational driving force of the sun roller 30 is transmitted from the input shaft 20 through the input roller 91 to the planetary roller 40 and is transmitted to the output shaft 120 at a desired timing.

On the other hand, when the rotational speed of the input shaft 20 (sun roller 30) decreases, the weight 101 moves closer to the radial axis L due to the urging force of the spring 103, and the force pushing the inclined plate 102 becomes weaker. The force also acts, and the sun roller 30 slightly moves (turns off) so as to escape from the corresponding planetary rollers 40. As a result, the traction force is reduced, the rotational driving force of the input shaft 20 (sun roller 30) is not transmitted to the planetary roller 40, and the output shaft 120 rotates freely regardless of the rotation of the input shaft 20 (sun roller 30) ( It can be rotated by external force).
In this way, when the trigger mechanism 100 is turned on, the sun roller 30 is formed so as to enhance the wedge action, so that the normal force, that is, the traction force on the contact surface between the sun roller 30 and the planetary roller 40 can be reliably obtained. be able to.

  In addition, since the trigger mechanism 100 is disposed between the input roller 91 and the sun roller 30, the trigger mechanism 100 transmits the rotational force in a speed increasing state after the rotational speed of the input shaft 20 is increased by the speed increasing mechanism 90. Turns on / off. Therefore, compared to the case where the rotational speed of the input shaft 20 is directly received, a centrifugal force that is N times proportional to the square of the rotational speed is obtained, and hence the mass of the weight 101 and the like that receives the centrifugal force is reduced to 1 / N times. can do.

As shown in FIGS. 2 and 5A and 5B, the loading cam mechanism 110 is integrated with the first cam rotating plate 111 connected to the end face 52 of the output ring 50 and the end of the output shaft 120. A second cam rotating plate 112 formed in the above, a spherical rolling element 113 interposed between the first cam rotating plate 111 and the second cam rotating plate 112, and the like.
As shown in FIGS. 5A and 5B, the first cam rotating plate 111 has a plurality of (here, three) cam grooves 111a and a shaft portion 91c of the input roller 91 as shown in FIG. It has a cylindrical portion 111b that is rotatably fitted.
As shown in FIGS. 5A and 5B, the second cam rotating plate 112 has a plurality of (here, three) cam grooves 112a.

When the loading cam mechanism 110 causes a relative rotational difference between the output ring 50 and the first cam rotating plate 111 and the second cam rotating plate 112 of the output shaft 120, the rolling element 113 moves and the cam groove moves. The cam action is received by 111a and 111b, and a pressing load (thrust load) is generated in the direction of the axis L. Then, the output ring 50 (the inner peripheral surface 51 thereof) is pressed against the first conical portion 41 of the planetary roller 40 to increase the normal force, and the output ring 50 and the output shaft 120 are integrated as a reaction force of the thrust load. Rotate.
Specifically, the rotational driving force of the input shaft 20 is transmitted to the output shaft 120 via the speed increasing mechanism 90 → the sun roller 30 → the planetary roller 40 → the output ring 50 → the loading cam mechanism 110, and conversely, the output shaft The load torque of 120 increases the pressing force (normal load), that is, the traction force that presses the output ring 50 against the planetary roller 40 via the loading cam mechanism 110. Therefore, even if a load torque is applied from the outside, the traction force is not increased. The output shaft is reliably rotated and driven at a predetermined speed ratio.

As shown in FIG. 2, the output shaft 120 is rotatably supported by a reduced diameter shaft portion 121 protruding to the outside of the housing 10 and an angular bearing 15 fitted to the housing 10, and the second cam rotation described above. A diameter-enlarged portion 122 that integrally forms the plate 112, a cylindrical fitting hole 123 that rotatably fits the cylindrical portion 111b of the first cam rotating plate 111, and the like are provided.
As shown in FIG. 2, the output shaft 120 is rotatably supported by the housing 10 via an angular bearing 15 and a ring seal 16, and rotates around the axis L (on the same axis as the input shaft 20). It is free to move.

Next, the operation of the continuously variable transmission will be described. First, when the input shaft 20 is stopped, no traction force is generated in the transmission unit U and no torque is transmitted, so that the output shaft 120 is in a freely rotatable state (off state).
Subsequently, the input shaft 20 starts rotating from a stopped state, and the rotation is accelerated to a predetermined speed by the speed increasing mechanism 90. When the rotational speed of the input shaft 20 increases, the trigger mechanism 100 is turned on ( The weight 101 moves outward in the radial direction to cause the sun roller 30 to enter the plurality of planetary rollers 40 by a wedge action), and the sun roller 30 is pressed against the planetary roller 40 to generate a normal force or traction force of a predetermined level or more. The torque (rotational driving force) is transmitted from the sun roller 30 to the planetary roller 40.

In the speed change unit U, the speed change ring 60 is appropriately driven by the drive mechanism 70, and the rotational speed changed through the sun roller 30 → the plurality of planetary rollers 40 → the output ring 50 is output via the loading cam mechanism 110 to the output shaft 120. Is output as a rotational driving force.
On the other hand, when a load torque is applied to the output shaft 120, the loading cam mechanism 110 is operated to increase the pressing force (normal load), that is, the traction force that presses the output ring 50 against the planetary roller 40. As a result, even when a load torque is applied from the outside, a traction force is reliably obtained, and the output shaft 120 is reliably rotated at a predetermined speed ratio.

  Here, since the rotational speed of the input shaft 20 is increased by the speed increasing mechanism 90 and transmitted to the speed change unit U, the transmission torque due to the traction force is reduced by the increased speed, and the direction of the axis L generated by the loading cam mechanism 110 is reduced. The ratio of the thrust load can be reduced with respect to the transmission output (output torque), and therefore the loss of the bearing supporting the input shaft 20 (bearing loss) can be reduced. In particular, transmission efficiency can be improved in a region where the gear ratio is small. Further, since the rotational speed of the input shaft 20 is increased by the speed increasing mechanism 90, the transmission output (output torque) is also improved by the speed increase, and the transmission output can be improved as a whole.

In the above-described embodiment, the configuration including the sun roller 30, the plurality of planetary rollers 40, the output ring 50, the transmission ring 60, and the like is shown as the transmission unit U that shifts using traction force. However, the present invention is not limited to this. Alternatively, as long as the traction force is used for continuously variable transmission, a transmission unit having another structure may be employed.
In the above-described embodiment, the case where the traction planetary mechanism including the input roller 91, the plurality of revolving rollers 92, and the like is employed as the speed increasing mechanism 90 is shown, but is not limited thereto, and the rotation of the input shaft 20 is not limited thereto. As long as the speed can be increased and transmitted to the transmission unit U, a speed increasing mechanism having another structure may be adopted.
Although the case where the trigger mechanism 100 is employed has been described in the above embodiment, the present invention is not limited to this, and the present invention may be employed in a configuration in which the trigger mechanism is eliminated.
In the above embodiment, the case where the output shaft 120 is arranged coaxially with the input shaft 20 is shown, but the present invention is not limited to this, and in the configuration in which the output shaft is arranged deviated from the input shaft, The present invention may be adopted.

  As described above, the continuously variable transmission of the present invention ensures sufficient traction force or transmission torque while achieving simplification of structure, size reduction, cost reduction, improvement in functional reliability, and the like. Because it can reduce transmission loss (bearing loss) and improve transmission efficiency, and can stably shift to a desired gear ratio, it can be mounted on vehicles such as motorcycles and four-wheelers. It can be applied as a transmission, and is useful for general-purpose machines, construction machines, agricultural machines, machine tools, and the like.

It is a fragmentary sectional view showing one embodiment of continuously variable transmission concerning the present invention. It is sectional drawing which shows the inside of the continuously variable transmission shown in FIG. FIGS. 3A and 3B show a speed increasing mechanism showing a part of the continuously variable transmission shown in FIG. 2, wherein FIG. 2A is a cross-sectional view taken along a plane including an axis, and FIG. . FIG. 3 is a schematic diagram showing a schematic configuration of the continuously variable transmission shown in FIG. 2. FIG. 3 shows a loading cam mechanism included in the continuously variable transmission shown in FIG. 2, (a) is an exploded perspective view showing an outline, and (b) is a partial sectional view. It is sectional drawing which shows the conventional continuously variable transmission. It is a graph which shows the transmission efficiency of the bearing in the conventional continuously variable transmission.

Explanation of symbols

L axis 10 housing 11 housing body 12 flange wall portion 13 radial bearing 14 ring seal 15 angular bearing 16 ring seal 17 coupling guide rod 18 fixed cylindrical portion 18a inner peripheral surface 20 input shaft 21 reduced diameter shaft portion 22 enlarged diameter portion 23 support portion 24 fixed portion U transmission unit 30 sun roller 31 outer peripheral surface 32 skirt portion 33 cylindrical portion 34 through hole 40 planetary roller 41 first conical portion 42 second conical portion 43 shaft portion 50 output ring 51 inner peripheral surface 52 end surface portion 60 transmission ring 61 Inner peripheral surface 62 Female threaded portion 63 Guided portion 70 Drive mechanism 71 Lead screw 72 Drive motor 80 Movable holder 90 Speed increasing mechanism 91 Input roller 91a Outer peripheral surface 91b Disk portion 91c Shaft portion 92 Revolving roller 93 Holding ring 100 Trigger mechanism 101 Weight 102 inclined plate 1 3,104 spring 105 receiving unit 110 loading cam mechanism 111 first cam rotating plate 111a cam groove 112 and the second cam rotating plate 112a cam groove 113 rolling element 120 output shaft 121 reduced diameter portion 122 enlarged diameter portion 123 fitting hole

Claims (9)

An input shaft that is rotatably supported around a predetermined axis with respect to the housing, a transmission unit that continuously changes the rotation of the input shaft by traction force, and an output shaft that is rotatably supported by the housing A continuously variable transmission comprising a loading cam mechanism that is interposed between the transmission unit and the output shaft and generates a pressing load in the axial direction;
A speed increasing mechanism is provided between the input shaft and the speed change unit to increase the rotational speed of the input shaft and transmit the speed to the speed change unit.
A continuously variable transmission. The transmission unit includes a frustoconical sun roller that is accelerated by the speed increasing mechanism and rotates about the axis, a plurality of planetary rollers that roll on the outer peripheral surface of the sun roller, and the planetary roller inscribed therein. A rotating output ring and a conical portion formed integrally with the planetary roller are inscribed in a freely rotatable manner, and the inscribed position is moved in the axial direction so as to change speed by moving. Including a modified transmission ring,
The continuously variable transmission according to claim 1. The speed increasing mechanism rolls on an input roller that can rotate integrally with the sun roller, an inner peripheral surface of a fixed cylindrical portion formed on the housing so as to be coaxial with the axis, and an outer peripheral surface of the input roller. A plurality of revolving rollers coupled to the input shaft to revolve around the axis,
The continuously variable transmission according to claim 2. The speed increasing mechanism is formed so as to receive a load in the axial direction applied toward the input shaft.
The continuously variable transmission according to claim 3. Including a trigger mechanism for turning on / off the transmission of the rotational force by the traction force between the sun roller and the planetary roller according to the rotational speed of the input shaft,
The continuously variable transmission according to claim 2. The trigger mechanism changes a pressing load in the axial direction according to a centrifugal force around the axis, and is arranged between the input roller and the sun roller.
The continuously variable transmission according to claim 3. The input roller has a shaft centered on the axis,
The sun roller is connected to the shaft portion so as to rotate integrally and move in the axial direction.
The continuously variable transmission according to claim 6. An annular movable holder that supports the plurality of planetary rollers so as to rotate and revolve around the axis;
The speed increasing mechanism is disposed in an inner region of the movable holder,
The continuously variable transmission according to claim 2. An annular movable holder that supports the plurality of planetary rollers so as to rotate and revolve around the axis;
The sun roller has a cylindrical portion centered on the axis,
The movable holder is rotatably supported by a fixed cylindrical portion of the housing and a cylindrical portion of the sun roller.
The continuously variable transmission according to claim 3.

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