JP2001330096A - Continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an arrangement space for a transmission mechanism to transmit the drive power of a motor for speed change to the speed change gear of each pulley. SOLUTION: A continuously variable transmission comprises a drive pulley 11 having a speed change gear 14d and a screw mechanism 14; a driven pulley 21 having a speed change gear 22d and a screw mechanism 22; and a belt 15 running around and between the drive pulley and the driven pulley. The speed change gears 14d and 22d are rotated by a motor 40 for speed change and moving sheaves 11b and 21b are axially moved through the screw mechanisms 14 and 22. The speed change gears 14d and 22d form a gear having diameter larger than that of the moving sheave of each pulley. The drive force of the motor 40 for speed change is transmitted to a speed change shaft 45 and transmitted to the speed change gear 14d from a gear 45a mounted on the speed change shaft 45 and to the speed change gear 22d of the driven pulley 21 through idler gears 46a and 46b. This constitution synchronously rotates the speed change gears 14d and 22d by the single motor 40 for speed change.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a continuously variable transmission, and more particularly to a V-belt type continuously variable transmission for a vehicle.

[0002]

2. Description of the Related Art Various types of continuously variable transmissions have been proposed and some of them have been put to practical use. The continuously variable transmission includes a drive shaft having a drive pulley, a driven shaft having a driven pulley, and a belt wound between the drive pulley and the driven pulley, and is provided on each of the drive pulley and the driven pulley. The gear ratio can be varied steplessly by operating the actuator to change the belt winding diameter of each pulley in the opposite direction. Therefore, there is an advantage that smooth running can be realized without any shift shock.

In Japanese Patent Application Laid-Open No. 64-58848, a ball screw mechanism is provided as an actuator for changing the belt winding diameter of a driving pulley and a driven pulley, and the ball screw mechanisms of both pulleys are operated by one speed change motor. There has been proposed a continuously variable transmission in which a movable sheave is moved in an axial direction. In the case of this continuously variable transmission, the driving force of a speed change motor is transmitted to an operation shaft via a reduction gear mechanism, and two gears provided on the operation shaft are a transmission gear of a driving pulley and a transmission gear of a driven pulley. , The transmission gears of both pulleys are synchronously rotated, and the movable sheave is moved in the axial direction via a ball screw mechanism.

[0004]

However, the transmission gear of the driving pulley and the transmission gear of the driven pulley are smaller in diameter than the movable sheave, and the two gears of the operation shaft overlap the movable sheave in the radial direction. Since the gear has a large diameter, the gear of the operating shaft must be arranged at a position where it does not interfere with the movable sheave when the movable sheave moves in the axial direction. The movable sheave is provided at the reciprocal position of each pulley, and the transmission gear of the driving pulley and the transmission gear of the driven pulley are provided behind the movable sheave. Overhang. Therefore, the transmission mechanism for transmitting the driving force of the transmission motor to the transmission gear of each pulley occupies a large space, and has a disadvantage that the entire continuously variable transmission becomes large.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a continuously variable transmission which can reduce the space for disposing a transmission mechanism for transmitting the driving force of a speed change motor to a speed change gear of each pulley, thereby reducing the size as a whole. .

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to a driving pulley having a transmission gear and a screw mechanism, a driven pulley having a transmission gear and a screw mechanism, and a driving pulley. A belt wound around a driven pulley, and a transmission motor synchronously rotates a transmission gear of the driving pulley and a transmission gear of the driven pulley, whereby a movable sheave of the driving pulley and a driven pulley are driven via a screw mechanism. In the continuously variable transmission in which the movable sheave is moved in the axial direction and the speed ratio is continuously variable, the transmission gear of the driving pulley and the transmission gear of the driven pulley have a larger diameter than the movable sheave of each pulley. A first transmission shaft having a gear to which a driving force is transmitted from the transmission motor and meshing with a transmission gear of a driving pulley or a driven pulley; Providing CVT is characterized by providing a second transmission shaft having an idler gear meshing with the respective gear of the driven pulley, the.

The power input to the driving pulley is transmitted to a driven pulley via a belt. At this time, the transmission gears provided on the two pulleys are synchronously rotated by the transmission motor via the first transmission shaft and the second transmission shaft, so that the movable sheaves of the two pulleys are axially moved via the screw mechanism. To change the gear ratio steplessly. In the case of the present invention, the transmission gear of the driving pulley and the transmission gear of the driven pulley are gears having a larger diameter than the movable sheave of each pulley, so that the gear provided on the first transmission shaft and the second transmission shaft are provided. The provided idler gear,
A small-diameter gear that does not overlap with the movable sheave of each pulley in the radial direction can be provided. Therefore, the space for disposing the transmission mechanism that transmits the driving force of the speed change motor to the speed change gear of each pulley can be reduced.

In the case of the conventional example (Japanese Patent Laid-Open Publication No. Sho 64-58848), the driving force of the speed change motor is distributed to the speed change gears provided on both pulleys via the operation shaft. Not only the shaft, but also the speed change motor and the mechanism that transmits the driving force of the motor to the operation shaft must be located near the intermediate position between the two pulleys, which easily interferes with other drive mechanisms, and the degree of freedom of arrangement is low. . On the other hand, in the present invention, the driving force of the speed change motor is transmitted in a tandem transmission path such as the first speed change shaft, the speed change gear of one pulley, the second speed change shaft, and the speed change gear of the other pulley. Since the transmission is performed, the speed change motor can be arranged at a position outside one of the pulleys, and the degree of freedom of arrangement is high.

According to a second aspect of the present invention, the screw mechanism comprises a female screw member rotatably attached to the movable sheave of each pulley via a bearing, and a male screw member fixed to the transmission case. Then, the transmission gear of the driving pulley and the transmission gear of the driven pulley are fixed to the female screw member.
The gear of the transmission shaft and the idler gear of the second transmission shaft,
It is preferable that the gears have an axial dimension corresponding to the axial displacement of the movable sheave of each pulley. That is, when the transmission gear of the pulley is smaller in diameter than the movable sheave as in the conventional example, an axially longer gear must be used as the transmission gear of the pulley in order to mesh with the gear of the operating shaft. Since this transmission gear moves in the axial direction together with the movable sheave, a large axial movement space must be ensured. On the other hand, in the present invention, since the transmission gear of the pulley is a gear having a larger diameter than the movable sheave, by using a gear that is long in the axial direction as the gear of the transmission shaft, the transmission gear can be a thin gear. Thus, the axial movement space of the transmission gear can be reduced.

According to a third aspect of the present invention, a speed change motor and a gear mechanism for transmitting the driving force of the speed change motor to the first speed change shaft are provided in a motor housing, and the motor housing is attached to a transmission case, so that the output of the gear mechanism is obtained. Preferably, the shaft is configured to be connected to the first transmission shaft. That is, the transmission motor and the gear mechanism are integrally provided in the motor housing to form an assembly, and the motor housing is attached to the transmission case and the output shaft of the gear mechanism is connected to the first transmission shaft. In addition to improving workability, when it is desired to change the reduction ratio from the speed change motor to the first speed change shaft, simply change the speed change ratio of the gear mechanism to the changed motor housing, and the transmission case and the first and first gear ratios are changed. There is no need to change the second transmission shaft, and the change can be made at low cost. Further, since the motor housing and the inside of the transmission case are separated from each other, it is possible to prevent the lubricating oil in the motor housing from flowing into the transmission case even when the inside of the transmission case is a non-lubricated space. Is also possible.

[0011]

1 to 4 show a specific structure of an example of a continuously variable transmission according to the present invention, and FIG. 5 shows a skeleton structure thereof. This continuously variable transmission is an FF horizontal type transmission, and generally includes a starting mechanism 2 driven by an engine output shaft 1, an input shaft 3 as an output shaft of the starting mechanism 2, a power shaft 4,
A drive shaft 10 having a drive pulley 11, a driven shaft 20 having a driven pulley 21, a V-belt 15 wound around the drive pulley 11 and the driven pulley 21, a reduction shaft 30, an output shaft 32 connected to wheels, a speed change motor. 40, a tensioner device 50 and the like. The input shaft 3, the power shaft 4, the drive shaft 10, the driven shaft 20, the reduction shaft 30, and the output shaft 32 are all non-coaxial and arranged in parallel.

The starting mechanism 2 of this embodiment is constituted by a dry clutch, and by operating the release fork 2a by a starting control motor (not shown), it is possible to perform connection / disconnection control and half-clutch control. . The input shaft 3 is rotatably supported by a transmission case 6 via a bearing, and a forward gear 3a and a reverse gear 3b provided so as to be integrally rotatable with the input shaft 3 are connected to a second gear chamber of the transmission case 6. 6c.

The power shaft 4 is provided so as to span the left and right side walls of the transmission case 6, and both ends are rotatably supported by bearings. A forward gear 4a that meshes with a forward gear 3a of the input shaft 3 is integrally provided at an end of the power shaft 4 on the engine side, and a reduction gear 4b is fixed to an opposite end of the power shaft 4 on the engine side. The reduction gear 4b of the power shaft 4 is a reduction gear 1 rotatably supported at an end of the drive shaft 10 on the side opposite to the engine.
0a, and the driving force is transmitted from the power shaft 4 to the drive shaft 10 at a reduction ratio suitable for belt driving. Reduction gear 10
a is selectively connected to the drive shaft 10 by a synchro-type forward switching unit 12 provided on the side of the drive shaft 10 opposite to the engine. That is, the switching unit 12 can switch between two positions, that is, the forward position D and the neutral position N. The reduction gear 4b, the reduction gear 10a, and the forward switching unit 12 constitute a forward direct coupling transmission mechanism 13. The forward direct coupling transmission mechanism 13 includes a first gear chamber 6 formed on the side of the transmission case 6 opposite the engine.
a. The inside of the first gear chamber 6a is lubricated with oil.

The drive pulley 11 includes a fixed sheave 11a fixed on the drive shaft 10, a movable sheave 11b supported on the drive shaft 10 so as to be movable in the axial direction, and a movable sheave 11b.
, And the actuator 14 is disposed on the engine side of the V-belt 15. The actuator 14 of this embodiment is a ball screw mechanism that is moved in the axial direction by a speed change motor 40. The actuator 14 has a female screw member 14b rotatably supported by a movable sheave 11b via a bearing 14a, and a transmission case 6. The transmission gear 14d is fixed to an outer peripheral portion of the female screw member 14b.
The transmission gear 14d is a gear having a larger diameter and a smaller thickness than the movable sheave 11b constituting the drive pulley 11.

The driven pulley 21 includes a fixed sheave 21a fixed on the driven shaft 20, a movable sheave 21b supported on the driven shaft 20 so as to be movable in the axial direction, and a movable sheave 21b.
And an actuator 22 provided behind the V-belt 15, and the actuator 22 is disposed on the side opposite to the engine with respect to the V-belt 15. This actuator 22 is also used as the drive pulley 11
A ball screw mechanism having a configuration similar to that of the actuator 14, comprising a female screw member 22 b rotatably supported by a movable sheave 21 b via a bearing 22 a, and a male screw member 22 c supported by the transmission case 6. A transmission gear 22d is fixed to an outer peripheral portion of the female screw member 22b. The transmission gear 22d is also a gear having a larger diameter and a smaller thickness than the movable sheave 21b constituting the driven pulley 21.

A reverse gear 24 is rotatably supported at a portion of the driven shaft 20 closer to the engine than the driven pulley 21. The reverse gear 24 meshes with a reverse gear 3 b fixed to the input shaft 3. . The gear 24 is selectively connected to the driven shaft 20 by a synchro-type reverse switching means 25. That is, the switching unit 25 is configured to switch the reverse position R and the neutral position N
Can be switched to the two positions. The reverse gear 3b, the gear 24, and the reverse switching means 25 constitute a reverse direct transmission mechanism 26.

A reduction gear 27 is formed integrally with the end of the driven shaft 20 on the engine side. The reduction gear 27 meshes with a gear 30 a fixed to the reduction shaft 30, and is formed integrally with the reduction shaft 30. And the ring gear 31a of the differential 31 via the gear 30b. Reduction axis 3
The speed reduction mechanism 29 is constituted by the zero gears 30a and 30b and the ring gear 31a. And the differential device 3
The wheels are driven via an output shaft 32 provided on the vehicle.
The reverse direct connection transmission mechanism 26, the reduction shaft 30, and the differential device 31 are formed on a second side formed on the engine side of the transmission case 6.
It is housed in the gear chamber 6b. The gear chamber 6b is lubricated with oil. The gear chamber 6b also accommodates a forward gear 3a of the input shaft 3 and a forward gear 4a of the power shaft 4, and is similarly lubricated.

The first gear chamber 6a and the second gear chamber 6b of the transmission case 6 are lubricated as described above, and the drive pulley 11 and the driven pulley 21 are divided into the first gear chamber 6a and the second gear chamber. 6b is disposed in a pulley chamber 6c sandwiched between the pulley chamber 6c and the pulley chamber 6b. In this embodiment, the pulley chamber 6c is a non-lubricated space,
The V belt 15 is also a dry drive belt.

To circulate the lubricating oil in the first gear chamber 6a and the lubricating oil in the second gear chamber 6b separated in the axial direction,
A supply oil passage and a return oil passage are formed by a shaft hole (first oil passage) 4c of the power shaft 4 and a radial gap (second oil passage) 5 between a second transmission shaft 46 and the power shaft 4 described later. Are formed. Either the shaft hole 4c or the radial gap 5 may be a supply oil passage or a return oil passage. By circulating the oil in the gap 5 between the power shaft 4 and the second transmission shaft 46 in this manner, the space between the two shafts can be lubricated.

The power transmission paths of the continuously variable transmission having the above-described configuration during forward movement and reverse movement will be described with reference to FIGS. At the time of forward travel, the shift lever is operated to switch the forward switching means 12 to the forward position D. At this time, the reverse switching means 25 automatically switches to the N position. As shown in FIG. 6, the power input from the starting mechanism 2 via the input shaft 3 is transmitted by a forward gear 3a, a forward gear 4a, a power shaft 4, a forward direct transmission mechanism 13 as shown by a thick arrow.
(Reduction gear 4b, reduction gear 10a, forward switching means 1
2), drive shaft 10, drive pulley 11, V-belt 15, driven pulley 21, driven shaft 20, reduction gear 27, reduction shaft 3
0, transmitted to the output shaft 32 via the differential device 31. On the other hand, at the time of reverse travel, the shift lever is operated to switch the reverse switching means 25 to the reverse position R. At this time, the forward switching means 12 automatically switches to the N position. As shown in FIG. 7, the power input from the starting mechanism 2 via the input shaft 3 is transmitted to the reverse direct transmission mechanism 26 as shown by the thick arrow.
(Reverse gear 3b, reverse gear 24, reverse switching means 2
5), transmitted to the output shaft 32 via the driven shaft 20, the reduction gear 27, the reduction shaft 30, and the differential device 31. As described above, the continuously variable transmission unit including the driving pulley 11, the driven pulley 21, and the V-belt 15 is driven only when the vehicle is moving forward, and is not driven when the vehicle is moving backward, so that no reverse load is applied to the V-belt 15 and the load can be reduced. That is, as described later, the V belt 1
5, a tensioner device 50 for pressing the loose side to apply a belt thrust is provided, but when the V-belt 15 rotates in the reverse direction, the loose side also reverses, so that the tensioner device 50 presses the tension side, and the V-belt 15 Because an excessive load is applied to the

Next, the speed change mechanism of the continuously variable transmission will be described. A speed change motor 40 is attached to an outer portion of the transmission case 6, particularly a portion obliquely above the drive pulley 11 (see FIG. 8). The speed change motor 40 is a servomotor having a brake 41, and its output gear 4
2 meshes with a reduction gear 43, and these gears 42, 43 are housed in a motor housing 44 lubricated with oil and are assembled in advance. The shaft 43a of the reduction gear 43 projects from the motor housing 44, and the motor housing 4
When the transmission 4 is fixed to the transmission case 6, the shaft portion 43a is spigot-fitted to a sleeve-shaped first transmission shaft 45 rotatably supported by the transmission case 6, and is connected to be integrally rotatable. Thus, the motor housing 44 and the transmission case 6
Is isolated from the inside of the motor housing 44.
It is possible to prevent the lubricating oil inside the casing from flowing into the transmission case 6. The gear 45a provided on the first transmission shaft 45 is a trapezoidal gear having a length corresponding to the movement stroke of the movable sheave 11b, and meshes with the transmission gear 14d provided on the drive pulley 21. When the gear 45a of the first speed-change shaft 45 is rotated, the speed-change gear 14d is rotated to follow, so that the movable sheave 11b can be moved in the axial direction by the action of the ball screw mechanism (actuator 14). That is, the belt winding diameter of the driving pulley 11 can be continuously changed.

The speed change gear 14d of the drive pulley 11 meshes with a first idler gear 46a of a sleeve-shaped second speed change shaft 46 which is inserted into the outer periphery of the power shaft 4 so as to be relatively rotatable. The idler gear 46b meshes with the transmission gear 22d of the driven pulley 21. These idler gears 46a and 46b are also provided on the gear 4 of the first transmission shaft 45.
Like 5a, it is configured by a trapezoidal gear having a length corresponding to the moving stroke of the movable sheaves 11b and 21b. In this embodiment, two idler gears 46
Although the a and 46b are formed individually, these idle gears may be a single gear extending in the axial direction. Speed change motor 4
The zero rotational force is transmitted to the transmission gear 22d of the driven pulley 21 via the first transmission shaft 45, the transmission gear 14d of the drive pulley 11, and the second transmission shaft 46. Therefore, the movable sheave 11a of the driving pulley 11 and the movable sheave 21a of the driven pulley 21 can move in the axial direction while synchronizing with each other and changing the belt winding diameter in the opposite direction.

The reason for using a motor with a brake as the speed change motor 40 is that the gear train (42, 43, 45, 14d, 46a, 46a,
46b and 22d) are all constituted by reversible gears, and the gear train may rotate due to the reaction force of the movable sheave due to the belt tension and the gear ratio may change. This is to prevent rotation.

Next, a mechanism for applying a belt thrust to the V-belt 15 will be described. Pulleys 11, 21 as described above
The belt winding diameter of the V belt 15 is varied by the speed change motor 40, but the belt winding diameter of the V belt 15
And the pulleys 11 and 21 slip. Therefore, a tensioner device 50 as shown in FIGS. 3 and 4 is provided to apply a belt thrust (belt tension) according to the transmission torque. The tensioner device 50 includes a tension roller 51, and the tension roller 51 is swingably supported by an arm 53 via a link 52. The swing shaft 53a of the arm 53 is
Of the V-belt 1
It is biased in five directions. Therefore, the tension roller 51 presses the loose side of the V-belt 15 inward with a predetermined load. By pressing the V-belt 15 from the outside to the inside in this way, a predetermined belt thrust is obtained, and the V-belt 15 with respect to the pulleys 11 and 21 is obtained.
The length of the wrapping is increased to increase the transmission efficiency. A gear portion 53b is formed on the outer peripheral surface of the distal end portion of the arm 53, and a pinion gear 56 of a tension adjustment assist motor 55 meshes with the gear portion 53b. The spring 54 provides an initial thrust. By driving the assist motor 55 in either the forward or reverse direction, the motor thrust is adjusted with respect to the initial thrust so that an optimum belt thrust is obtained. I have. In the case of a vehicle having a relatively small change in transmission torque, the assist motor 55 may be omitted, and the thrust may be applied only by the spring 54. Further, the tension roller 51 is not limited to pressing the V belt 15 from the outside to the inside, but may press from the inside to the outside.

In the case of the tensioner device 50 described above, the tension roller 51 does not interfere with the pulleys 11 and 21.
The tension roller 51 is connected to an arm 53 through a link 52.
Attached to. The reason will be described with reference to FIGS. That is, when the tension roller 51 is directly attached to the arm 53 as in the related art, the tension roller 51 moves on a rotation locus about the swing shaft 53a of the arm 53, so that the continuously variable transmission changes from low to high.
When the gear is shifted to h, the tension roller 51 may interfere with one of the pulleys. In particular, in order to reduce the load on the V-belt 15, interference is likely to occur when a large-diameter tension roller 51 is used. On the other hand, when the tension roller 51 is attached to the arm 53 via the link 52, a two-degree-of-freedom link structure is obtained, and the Low roller shown in FIG.
In each speed ratio in the (lowest speed ratio) state, the Mid (intermediate ratio) state shown in FIG. 10, and the High (highest speed ratio) state shown in FIG. 11, the angle θ between the arm 53 and the link 52 is automatically set. And the tension roller 51 can automatically move to a position where there is no interference with the pulleys 11 and 21. Therefore, even when the large-diameter tension roller 51 is used as in the embodiment, the tension roller 51 and the pulleys 11 and 21 are not used.
Interference can be reliably prevented. The link structure is not limited to the two-degree-of-freedom link structure, but may be a three-degree-of-freedom link structure using two links.

The pivot shaft 53a of the arm 53 is arranged near the driving pulley 11 for the following reason. That is, as shown in FIGS. 9 to 11, the V-belt 15
, The pressing force T1 in the vertical direction changes, and a belt tension proportional to the pressing load T1 is generated. The pressing load T1 is given as a vector sum of a spring load T2 of the spring 54 and a load T3 in a direction perpendicular to the spring load T2.
Here, the biasing force by the assist motor 55 is neglected. By arranging the swing shaft 53a of the arm 53 near the drive pulley 11 as described above, a low to high
h, the angle θ between the arm 53 and the link 52 changes, and the pressing load T1 is Mid, Hi compared to when the pressing load T1 is Low.
gh is smaller. Therefore, even when the assist motor 55 is not used, it is small during Mid and High,
It is possible to obtain a large belt tension at the time of Low.

As shown in FIGS. 2 and 3, the input shaft 3 and the power shaft 4 of this embodiment are arranged at an intermediate position between the drive shaft 10 and the driven shaft 20 in the vertical direction. In particular, the power shaft 4 is driven by a V wound around the driving pulley 11 and the driven pulley 21.
It is inserted and disposed within the circumference of the belt 15. for that reason,
The input shaft 3 and the power shaft 4 are arranged between the space in the vertical direction between the drive shaft 10 and the driven shaft 20, so that the size in the vertical direction can be reduced.

The second speed change shaft 46 inserted through the power shaft 4
It is inserted and disposed within the circumference of the belt 15. In particular, the second
Idler gears 46a, 46b provided on the transmission shaft 46
Are transmission gears 14d, 22 having a larger diameter than the pulleys 11, 21.
To engage with d, a small trapezoidal gear is used.
Therefore, the movable sheaves 11b, 2 of the pulleys 11, 21
When the first sheave 1b moves in the axial direction for shifting, the movable sheave 1
1b, 21b can overlap with these idler gears 46a, 46b in the axial direction, and the axial dimension can be reduced. In addition, the thickness of the transmission gears 14d, 22d does not require the length of the moving stroke of the movable sheaves 11b, 21b, and the gears can be made thinner, so that the axial movement space of the transmission gears 14d, 22d can be reduced. . As a result, a small continuously variable transmission can be realized.

The drive shaft 10 is disposed above the driven shaft 20. In other words, the driven shaft 20 is
Since it is disposed below, the driven shaft 20 and the reduction shaft 3
0 and the differential gear 31 are arranged at the lower part of the transmission case 6, and lubricity is improved. In addition, the driven shaft 20 is
And the output shaft 32 and the driven shaft 20
Are disposed at substantially the same height as the output shaft 32. Therefore, the drive shaft 10, the driven shaft 20, and the output shaft 32 have a triangular arrangement in which the drive shaft 10 is the apex and the line connecting the driven shaft 20 and the output shaft 32 is the base. Therefore, the position of the center of gravity is located below, and a stable continuously variable transmission can be obtained.

In the continuously variable transmission according to this embodiment, starting control,
No equipment requiring a hydraulic pressure such as a hydraulic servo mechanism, a hydraulic clutch, and a torque converter is used to perform the shift control and the forward / reverse switching, and a start control motor, a shift motor 40, and a tension control All controls can be performed only by the assist motor 65. Therefore, an extremely simple, compact, and low-cost continuously variable transmission can be obtained without requiring a complicated and large-sized hydraulic control device unlike a general automatic transmission. In addition, there are naturally no problems such as oil pump loss, power loss due to oil viscosity, and change in gear shifting performance.

The present invention is not limited only to the above embodiment. In the above embodiment, a dry belt is used as the V belt, but a wet belt lubricated with oil may be used.
Further, although a dry clutch is used as the starting mechanism, the present invention is not limited to this, and a fluid coupling such as a torque converter, a wet clutch, an electromagnetic clutch, or the like can be used. Further, as the forward / reverse switching mechanism, the forward switching means 12 is disposed on the side opposite to the engine with respect to the drive pulley 11 and the reverse switching means 25 is disposed on the engine side with respect to the driven pulley 21, respectively. The forward switching means and the reverse switching means may be arranged adjacently on the same axis.

[0032]

As is apparent from the above description, claim 1
According to the invention described in (1), the transmission gear of the driving pulley and the transmission gear of the driven pulley are gears having a larger diameter than the movable sheave of each pulley, so that the gears of the first transmission shaft and the second transmission shaft are formed. The idler gear can be a small-diameter gear that does not overlap the movable sheave of each pulley in the radial direction. Therefore, the space for disposing the transmission mechanism for transmitting the driving force of the transmission motor to the transmission gear of each pulley can be reduced, and a small continuously variable transmission can be obtained as a whole. Further, since the driving force of the speed change motor is transmitted through a tandem transmission path of the first speed change shaft, the speed change gear of one pulley, the second speed change shaft, and the speed change gear of the other pulley, the speed change motor is driven. There is no need to dispose the transmission mechanism including at the intermediate position between the pulleys, and the transmission motor can be disposed at an outer position of one of the pulleys, and there is an advantage that the degree of freedom of arrangement is increased.

[Brief description of the drawings]

FIG. 1 is a developed sectional view of an example of a continuously variable transmission according to the present invention.

FIG. 2 is a side view of the internal structure of the continuously variable transmission of FIG.

FIG. 3 is a sectional view of a pulley portion of the continuously variable transmission of FIG.

FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a skeleton diagram of the continuously variable transmission of FIG. 1;

FIG. 6 is a skeleton diagram showing a power transmission path of the continuously variable transmission during forward movement.

FIG. 7 is a skeleton diagram showing a power transmission path of the continuously variable transmission during reverse travel.

FIG. 8 is a left side view of the continuously variable transmission of FIG.

FIG. 9 is a diagram illustrating a contact position between a tension roller and a belt at a low speed ratio.

FIG. 10 is a diagram illustrating a contact position between a tension roller and a belt at an intermediate ratio.

FIG. 11 is a diagram showing a contact position between a tension roller and a belt at a high speed ratio.

[Explanation of symbols]

 6 Transmission Case 10 Drive Shaft 11 Drive Pulley 14 Actuator (Screw Mechanism) 14b Female Thread Member 14c Male Thread Member 14d Transmission Gear 15 V Belt 20 Follower Shaft 21 Follower Pulley 22 Actuator (Screw Mechanism) 22b Female Thread Member 22c Male Thread Member 22d Transmission Gear 40 Transmission motor 45 First transmission shaft 45a Gear 46 Second transmission shaft 46a, 46b Idler gear

Claims (3)

[Claims] A driving pulley having a transmission gear and a screw mechanism; a driven pulley having a transmission gear and a screw mechanism;
A movable sheave of the drive pulley via a screw mechanism by synchronously rotating a shift gear of the drive pulley and a shift gear of the driven pulley by a speed change motor, comprising a belt wound around the drive pulley and the driven pulley. And the movable sheave of the driven pulley are moved in the axial direction, and the transmission gear of the driving pulley and the transmission gear of the driven pulley are moved from the movable sheave of each pulley in the continuously variable transmission in which the gear ratio is continuously variable. A first transmission shaft having a large-diameter gear, the driving force of which is transmitted from the transmission motor and meshing with a transmission gear of a driving pulley or a driven pulley; And a second transmission shaft having the following. 2. The screw mechanism comprises a female screw member rotatably mounted on a movable sheave of each pulley via a bearing, and a male screw member fixed to a transmission case. The transmission gear of the pulley and the transmission gear of the driven pulley are fixed to the female screw member, and the gear of the first transmission shaft and the idler gear of the second transmission shaft correspond to the axial displacement of the movable sheave of each pulley. The continuously variable transmission according to claim 1, wherein the continuously variable transmission is a gear having an axial dimension. 3. The speed change motor and its driving force are controlled by a first
A gear mechanism for transmitting to the transmission shaft is provided in the motor housing, and an output shaft of the gear mechanism is connected to the first transmission shaft by attaching the motor housing to a transmission case. Item 3. The continuously variable transmission according to item 1 or 2.