JP2015007481A - Continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuously variable transmission having a variator for providing stepless variation in a drive ratio, and a launch device, and having a control structure for applying same control signals to the variator for setting required torque and the launch device for setting a torque capacity.SOLUTION: The transmission has a variator which is coupled between a rotary transmission input and a rotary transmission output, to provide continuous variation in a transmission drive ratio, via a launch device such as a clutch. The variator and the launch device are constructed and arranged to exert a required torque defined by an input signal. The same control signal is used for controlling both of the variator torque and a torque capacity of the launch device. The vehicle launch can be controlled in a simple manner by progressively raising the relevant control signal, preferably a hydraulic signal. Furthermore, the present invention includes a method for applying a traction load onto a race of the variator, and setting a torque of the launch device larger than that of the variator.

Description

The present invention relates to a continuously variable transmission. One aspect of the present invention relates to the control of a starting device and the control of a variator of such a transmission.

In any continuously variable transmission, there are devices that provide a continuously variable transmission ratio. Such a device is referred to herein as a “variator”. In a vehicle transmission, provisions must be made for “launch”, ie for accelerating the vehicle from a stationary departure. In this connection, some transmissions rely on the use of “starting devices” such as clutches. This device serves to disconnect the engine from the driven wheels of the vehicle while the vehicle is stationary. In order to move the vehicle from the departure standby state, the transmission is set to low gear, the engine is set to generate an appropriate torque, and the starting device is gradually engaged to increase the speed of the driven wheels of the vehicle. However, the management of this process can be complicated.

An alternative approach that is well known in continuously variable transmissions is to apply the output of the variator to an epicyclic mixing gear, which physically decouples the output of the transmission from the input of the transmission. Without allowing the transmission to achieve a condition referred to as "geared neutral" that provides a virtually infinite speed reduction. This type of transmission does not require a starting device. Start is achieved simply by moving the variator ratio from the “gear neutral” value. However, such transmissions necessarily include structural complexity for certain problems with transmissions and controls.

It is useful to make a distinction between “ratio controlled” and “torque controlled” variators. A ratio controlled variator has some physical mechanism to adjust its own ratio to achieve the setpoint. For example, "half toroidal (half
-toroidal) "known variators of the rolling traction type typically have one part (eg, valve spool) operatively coupled to a variator roller with a position corresponding to the variator ratio, A valve is utilized that has another part that moves to set the ratio (eg, a movable sleeve that forms a valve port). The state of the valve depends on the relative position of these two parts, and the valve controls the pressure applied to the piston / cylinder structure acting on the variator roller. The result is a hydromechanical feedback loop in which the valve always compares the variator ratio to the desired value,
Adjust the variator ratio to achieve that value. The associated electronics selects the desired variator ratio and sends a signal representing it to the transmission.

In torque controlled variators there is no such physical configuration to adjust the variator ratio to a desired value. Instead, the variator receives a control signal representing the torque to be generated. International Application Publication WO2006 / 0275540 (PCT / GB2005
In the known all toroidal type variator as described in US / 03098), this signal is in the form of a hydraulic pressure. In response to this pressure, the variator produces the required torque at its input / output. The actual drive ratio of the variator can be changed automatically to adjust for speed changes resulting from the application of this torque to the associated inertial body.

Therefore, on the engine / input side of the transmission, the torque produced by the variator and the engine output torque are summed to determine the net torque that affects the rotational inertia of the engine and related parts, and so on. Determine the acceleration of the engine. On the wheel / output side of the transmission, the torque produced by the variator is summed together with the externally applied torque due to braking, road gradient, etc., to determine the torque used to accelerate the vehicle itself. The resulting speed change at both input and output includes changes in the variator ratio, and the variator automatically adjusts for such changes.

In known all toroidal rolling traction variators of the torque controlled type, the variator serves to generate a “reaction torque” corresponding to the control signal. Reaction torque is the sum of torque at the input and output of the variator. Equivalently, this can be defined to be the torque that must be applied to the variator mounting body in order to prevent the variator mounting body from turning.

The variator typically relies on traction between the rotating parts to transmit the driving force. For example, in the case of a toroidal race rolling traction variator, the roller frictionally engages a troidal concave variator race, through which the driving force is variable from the variator input to its output. Communicated. In order to provide traction between the rollers and the race, they must be biased towards each other. The biasing force used to cause traction in the variator is referred to herein as “traction load”. In principle, a fixed traction load can be used. However, this needs to be set high enough to avoid excessive slip between the roller and the race under all conditions. As a result, the selected traction load value is excessive for most conditions, resulting in reduced energy efficiency and premature wear on the rotating parts.

Therefore, conventionally, the traction load has been changed in synchronization with the applied torque. Particularly in a torque-controlled variator, the traction load is typically changed in proportion to the traction torque. This has the advantage of providing a constant traction factor. Adjustments to traction loads must sometimes be made very quickly to prevent slipping in the case of sudden “instantaneous” events such as emergency braking. In some existing devices, this is done by using hydraulic equipment to apply the traction load. In particular, the hydraulic pressure applied to control the piston coupled to the variator roller is also directed to the hydraulic actuator used to generate the traction load, and thus the force applied to the variator roller. And the traction load varies synchronously.

In this type of hydraulic device, it is common to provide a hydraulic “end stop” to limit the movement of the variator roller and prevent the roller from exiting the race. This may be useful, for example, by closing the fluid outlet from the cylinder containing one of the pistons mentioned above by the piston when it reaches the end of its intended travel, thereby constraining the movement of the piston. This can be done by increasing the pressure in the cylinder. The increased pressure also applies to the traction load actuator, which must be done when the change in reaction torque due to the action of the end stopper should be balanced by the corresponding change in traction load, which is This is necessary when slipping should not occur during the action of the stopper.

  WO2006 / 0275540 (PCT / GB2005 / 03098)

The present invention is intended to provide an improved CVT. In particular (but not exclusively), the present invention is intended to provide a CVT whose structure and control method is simple.

According to the first aspect of the present invention, the rotation input connectable to the rotation driver, the rotation output connectable to the wheel of the vehicle, and the rotation input and the rotation output to provide a stepless change in the drive ratio. And a launcher configured to selectively couple / decouple the rotational input and rotational output, the launcher being configured to provide the required torque capacity. A continuously variable vehicle transmission as arranged is provided. This transmission is characterized by having a control configuration in which the same control signal is applied to the variator to set the required torque and to the starting device to set its torque capacity.

The torque capacity of the starting device, which can take the form of a clutch, can be transmitted to the variator and is determined by the degree of its engagement in the hydraulically controlled clutch, for example by the applied fluid pressure It is. Controlling the clutch and variator torque using a single signal not only greatly simplifies the equipment needed to control the transmission,
Control of the starting process is also facilitated.

According to a second aspect of the present invention, at least a pair of partially toroidal recessed races that together define a generally toroidal variator cavity and are mounted for rotation on a common variator axis ( races) and at least two rollers that move between the races to move on the partially toroidal race and transmit the driving force at the variator drive ratio, the roller axis relative to the variator axis Provides a variator that can be tilted to change the slope of the variator and is mounted in such a way as to allow for a stepless change in the variator drive ratio. Are connected to the connection shaft via a mechanical traction load structure that helps to transmit torque between the connection shaft and the variator race and to provide the traction load force to the race as a function of the transmitted torque. Pressing the variator race so that the traction load force engages the roller to provide the traction required to transmit the driving force, and the variator has a mechanical abutment that limits the tilt of the roller That is.

The combination of a mechanical traction load device (instead of a hydraulic device) and a mechanical end stopper (instead of a hydraulic end stopper) is very advantageous. The mechanically generated traction load can vary depending on the required speed. Because the traction load occurs in response to the torque acting on the associated variator race and does not respond to the force applied to the rollers, the change in variator torque resulting from the action of the end stopper pulls the end stopper itself. Appropriate changes in traction load are automatically provided without the need for operative coupling to the load device.

According to the third aspect of the present invention, the rotation input connectable to the rotation driver, the rotation output connectable to the wheel of the vehicle, and the rotation input and the rotation output to provide a stepless change in the drive ratio. There is provided a method of controlling a continuously variable vehicle transmission having a variator coupled between and a launching device configured to selectively couple / decouple rotational input and rotational output, the method comprising: Control the variator to provide the desired reaction force torque and tune the variator reaction torque so that the torque applied to the starter by the variator is always less than the torque capacity of the starter And controlling the torque capacity of the starting device.

Therefore, the integrated control of the reaction force torque and the torque capacity of the starting device is simplified. Furthermore, this method facilitates a very advantageous method of managing start-up by progressively increasing the counter-reaction torque of the variator and the torque capacity of the starter, where the torque capacity of the starter is at least a slip of the starter. The torque applied to the starting device by the variator is always exceeded until it is gone, so until that time the transmission is maintained at its minimum ratio by the torque applied to it via the starting device.

1 is a schematic diagram illustrating a continuously variable transmission (“CVT”) constructed in accordance with the present invention. FIG. FIG. 2a is a more detailed view of a traction load device for use with a CVT as viewed along the radial direction, and FIG. 2b is a perspective view of a variator race showing its rear surface. It is the schematic which shows the hydraulic pressure control structure of CVT. It is a figure which shows the element with the variator used for CVT seen along the axial direction.

Specific embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings. FIG. 1 shows a CVT utilizing a toroidal race rolling traction type variator 10. More particularly, this is a double cavity full toroidal variator. The variator has first and second input races 12, 14 with respective faces 16, 18 that are recessed in a semi-toroidal manner. Between the input races, there are first and second output races 20, 22 which have respective semi-toroidal concave surfaces 24, 26, so that the first input and output races 12, A first toroidal cavity 28 is formed between 20 and a second toroidal cavity 30 is formed between the second input and output races 22, 14. The races have a common axis of rotation defined by a main shaft, indicated schematically at 32, about which the race rotates.

Each cavity 28, 30 includes a respective set of rollers 34, 36. Each roller is mounted for rotation about a roller axis such as 38 and moves on its associated input and output race toroidal surfaces to transmit drive force from one to the other. The roller mount (not shown in FIG. 1 but briefly described) can change its slope according to the change in the variator drive ratio, i.e. between the roller axis 38 and the main shaft 32. The angle can be changed. The main shaft 32 acts as a rotational input to the variator, which in this particular embodiment is directed to a rotary driver such as an engine in the form of an internal combustion engine, indicated schematically at 40 (directly or intermediately). (Via not shown).

The present invention can equally well be implemented using different types of rotary drivers such as electric motors, external combustion engines and the like. The variator input races 12, 14 are fixed to the main shaft 32 so as to rotate together and are therefore driven by the engine 40. Output race 20,
22 can rotate with respect to the main shaft 40. In the embodiment shown, this is provided by roller bearings 42, 44, through which the output races are each mounted on the main shaft 32. The driving force is transmitted from the input races 12 and 14 to the output races 20 and 22 through the rollers 34 and 36 at a variable drive ratio (or vice versa in the “overrun” state). The output races 20, 22 are also the final driver 46 leading to the vehicle wheels.
This will be briefly described.

In the illustrated variator 10, the variator races 12, 14, 16, 18 are such that the traction load engages the variator rollers 34, 36 with a force proportional to the output torque of the variator (“traction load”).
Is provided by a mechanical (non-hydraulic) traction load device 48 that helps to bias This is done by pressing the two innermost races (in the illustrated embodiment, output races 20, 22) away from each other. The traction load is transmitted via rollers 34, 36 to the outermost race, which in this embodiment is the input race 12, 14, which then applies force to the main shaft 32 so that the main shaft is in tension. It is burned. By applying a traction load to the main shaft 32 in this manner, any need for a thrust bearing to withstand the traction load is avoided.

The traction load device 48 uses a simple ramp configuration to transmit the output torque, which is a function of the transmitted torque (particularly in this embodiment, proportional to the transmitted torque) A traction load is generated along the axial direction.

2a and 2b reveal the structure of the traction load device 48. FIG. The output drive gear 50 is fixed to the rear surface of the output race 22. On the side far from the output race 22, the output drive gear 5
0 has a set of sloping indentations as indicated by the dashed line 52 in FIG. On its own rear face, the output race 20 has a corresponding set of sloped depressions 54 as clearly shown in FIG. 2b. Recesses 52, 54 have a partially circular cross section (when viewed along the circumferential direction in FIG. 1) to accept rollers 56, which in this embodiment are formed as spherical balls. When viewed along the radial direction, the indentations 52, 54 appear to have a shallow “V” shape. The separation of the output drive gear 50 and the output race 20 is minimized when the deepest areas of the depressions 52, 54 are aligned as in FIG. 2a, in which case the position of the ball 56 itself is within these areas.

However, consider that variator output occurs when necessary to maintain torque. Note that the output race 20 can rotate relative to the output drive gear 50 due to the bearings 42, 44. When the output torque causes relative rotation of these parts, the indentations 52, 54
The deepest section of the rim is misaligned, so that the ball 56 rides in the “V” shaped indentation and pushes the output race 20 away from the output drive gear 50, thereby creating the required traction load. This relative rotation stops when the resulting traction load is balanced with the transmitted torque. Therefore, the traction load is a function of the output torque as described above. The exact nature of this function depends on the formation of the indentations 52, 54, but in the illustrated embodiment, one is proportional to the other.

The illustrated transmission can provide both forward and reverse gears, i.e., the final driver 46.
The direction of rotation can be reversed. This is accomplished by providing two paths for power drawn from the output races 20,22. One of these paths is omitted in FIG. 1 for the sake of clarity, but is formed on an output drive gear 50 that drives the chain gear 60 through a drive chain that moves on the teeth 58 and the chain gear 60. Through one set of teeth 58. The chain gear 60 is operatively coupled to one side of the forward clutch 62 and the other side is operatively coupled to the final driver 46. The second path for power extraction is through a second set of teeth 64 formed on the output drive gear 50. These teeth 64 mesh with a gear wheel 66 operatively coupled to one side of the reverse clutch 68 and the other side is operatively coupled to the final driver 46.

Note that the first path 58, 60, 62 for power extraction does not provide reversal of the direction of rotation for the use of chain drive. Second path 64 for power extraction
, 66, 68 cause a reversal of direction for the use of a pair of gears. Therefore, engagement of forward clutch 62 causes rotation of the final driver in one direction and engagement of clutch 68 causes rotation of the final driver in the opposite direction. It should be noted that in this particular embodiment, forward and reverse clutches 62, 68 are configured in such a way as to prevent them from engaging simultaneously. The final driver 46 has a transmission device 70 that finally communicates with a vehicle wheel (not shown).

As described above, the mounting bodies for the rollers 34 and 36 are not shown in FIG. One suitable form of mounting is shown in FIG. In this figure, one of the variator races 12, 14, 20
Or 22 and one of two rollers 34 or 36. Its position is influenced via a control lever 72 which is pivotally mounted on a pendulum 74 received in a slot 76 of the control lever. The control lever has a substantially radially projecting lever arm 78 integrally formed with the crosspiece 80 to form an inverted “T” shape. Ball couplings 82 and 84 at both end portions of the crosspiece 80 carry the respective rollers and couple the crosspieces to respective roller bearings 86 and 88 which are rotatably mounted. It should also be noted that the two ball couplings 82, 84 are not in a common radial plane (not visible in FIG. 4).

In FIG. 1, the radial surface at the center of the toroidal cavity 30 is indicated by a dotted line 90.
The two ball couplings 86, 88 are each displaced from this central plane 90 and are present on either side thereof, so the line from the center of each ball coupling to the center of each roller 34, 36 is a radial plane. Tilt against. This inclination is called “caster angle”. Control lever 7
When 2 is moved, as is apparent from the figure, both rollers move correspondingly around the axis of the main shaft 32 either clockwise or counterclockwise. When moving like this,
The rollers are subjected to steering effects by variator races (in a manner well known to those skilled in the art). as a result,
Both rollers are tilted around the aforementioned line / axis passing through the ball coupling and the center of the roller. The steering effect on the roller always has a tendency to carry the roller at an inclination angle such that the axis of the roller intersects the axis of the main shaft 32. Because of the caster angle, the roller can always find the tilt angle that provides this intersection. The result is that the roller tilt and hence the variator ratio is a function of the position of the control lever 72.

The loads supported by the individual rollers are equal, and in the configuration of FIG. 4, it is important that the movement of the control lever 72 along the substantially radial direction defined by the slot 76 allows the roller loads to be equalized.

Actuator 92 is used to apply a controllable biasing force to lever arm 78. In this embodiment, the actuator 92 is a double acting hydraulic device. That is, the actuator receives two opposite hydraulic pressures and the force applied to it is determined by the difference between these two pressures, which can be left or right in FIG. It should also be noted that a single actuator in this embodiment controls the respective lever 72 of both variator cavities 28,30. Although the second control lever is not shown in FIG. 4, it should be understood that the bar 94 leads from one control lever 72 to the other, and the piston 96 of the actuator 92 is pivotally connected to the midpoint of this bar. . Therefore, the position of the piston 96 corresponds to the position of the midpoint of the bar, but if it is necessary to equalize the roller load between the two cavities, 2
The relative position of the two control levers can vary slightly.

Here, with reference to FIG. 3, the hydraulic equipment used in order to control CVT is demonstrated. In this figure, box 98 schematically illustrates a configuration for providing hydraulic fluid at an adjustable pressure. Suitable means for accomplishing this are known to those skilled in the art. This pressure is directed to the variator crossover valve 100, through which pressure can be applied to either side of the piston 96 to push the control lever 72 in one direction or in the opposite direction.
In FIG. 3, the exhaust stream from the low pressure side of the piston is shown as leading to sump 102, but in practice the exhaust stream is instead replaced by a low pressure source to avoid the entire chamber from being completely emptied. Can lead to. Actuator 92 applies a force to both control levers 72, the magnitude of which is determined by pressure source 98, the direction of which is the variator crossover valve 100.
Controlled by By adjusting this force, control is performed over the reaction force torque of the variator.

The pressure from the source 98 is also directed to the clutch selection valve 104. This valve selectively applies the above-described hydraulic pressure to either the forward clutch 62 or the reverse clutch 68.
Inoperative clutch pressure is discharged to sump 102 through the same valve. Therefore, the clutch selection valve 104 determines whether the transmission operates forward or reverse, and the pressure source 98 determines the force that engages the operating clutch and hence its torque capacity. The isolation valve 105 between the pressure source 98 and the clutch selection valve 104 is used when the vehicle is in a neutral state.
Helps selectively disconnect these components.

As noted above, some means is usually provided to limit the minimum and maximum variator ratios. In the absence of such means, the roller 34 is sufficient to leave the variator races 12, 14, 20, and 22.
, 36 can incline and can have catastrophic consequences. As mentioned above,
Such “end stops” are typically implemented hydraulically in the prior art. But,
In the illustrated embodiment of the invention, a simple mechanical stopper is placed in the path of movement of the roller. In particular, these stoppers limit the movement of a single actuator used to control all the rollers. In principle, the stopper can take any number of different forms, but FIG. 3 shows buffers 106, 108 in the actuator 92 that simply abut against the piston 96 when the end of its travel is reached. As shown.

The area of the piston 96 and the area of the piston in the forward and reverse clutches 62, 68 (the latter piston is not visible in the figure, but suitable clutch constructions are well known to those skilled in the art)
They are selected to ensure that the torque capacity of the actuating clutches 62, 68 exceeds the output torque of the variator, and of course both receive the same hydraulic pressure from the source 98. Therefore, consider what happens during the start of the vehicle. Prior to departure, the pressure on clutch select valve 104 is isolated valve 105.
Released by None of the clutches are engaged, so the vehicle wheels are decoupled from the variator.

To initiate a start, the clutch selection valve 104 is set to provide either forward or reverse, the pressure source 98 is set to a suitably low value, and then the state of the isolation valve 105 is related to this pressure. To be applied to the clutch to be. Since the torque capacity of the clutch always exceeds the output torque of the variator, the variator is first forced to adopt its minimum ratio as determined by the end stopper buffer 106. This occurs in any state of the variator crossover valve 100, but in fact the crossover valve 100 to avoid any "metal noise" caused by the clutch torque driving the variator to the end of its ratio range.
Is also initially set to push to its minimum ratio.

Engagement of the actuating clutch applies torque to the driven wheels and thus the vehicle begins to accelerate.
At some point during start-up, the state of the variator crossover valve 100 changes so that the applied hydraulic pressure tends to push the piston 96 away from its buffer 106 to increase the variator ratio. Have. As long as this change occurs while the actuating clutch is slipping, the timing of this change is not important. The reason is that during this time, the variator is kept in its minimum ratio by the torque generated by the actuating clutch 62 or 68 under any circumstances. As the vehicle accelerates, the pressure from the source 98 gradually increases and at some point the actuation clutch slips stop. Thereafter, with a continuous increase in hydraulic pressure, the piston 96 can be moved away from its end buffer 106, so that the variator ratio can increase as the vehicle accelerates.

During subsequent acceleration and braking, no slipping of the operating clutch can be expected. The reason is that the load applied to the clutch by the variator is smaller than its torque capacity. The effect can be controlled in a particularly simple manner in the management of the start-up, and the known CV for the hydraulic equipment
It is to provide a transmission that exhibits a greater simplification than T.

Modern vehicles typically use electronics to implement an integrated strategy for transmission and engine control. Here, the CVT under consideration is controlled in this way. The two most basic quantities to be controlled in this example are the variator reaction torque (set by pressure supply 98) and the engine output torque set by the torque demand supplied to the engine controller.

The embodiments described above are presented purely by way of example, and it will be apparent to the skilled reader that the present invention may actually be implemented in many different ways. For example, the illustrated embodiment utilizes a mechanical abutment to limit the roller travel and hence the variator ratio. However, in the industry, instead, an exit port from the actuator 92 is formed on the side of the cylinder so that excessive travel of the piston in either direction closes the exit port,
It is known to use a hydraulic arrangement that provides an end stop function. The same type of configuration can be used in the implementation of the present invention. Also, although the illustrated embodiment uses a mechanical ball and tilt configuration to provide traction load, this function can also be performed in other embodiments of hydraulic equipment. For example, it is well known to provide the same pressure to both the actuator 92 and the hydraulic piston / cylinder structure acting on one of the variator races to provide an end load, which is the same as the practice of the present invention. In the form of

Therefore, the integrated control of the reaction force torque and the torque capacity of the starting device is simplified. Furthermore, this method facilitates a very advantageous method of managing start-up by progressively increasing the counter-reaction torque of the variator and the torque capacity of the starter, where the torque capacity of the starter is at least a slip of the starter. The torque applied to the starting device by the variator is always exceeded until it is gone, so until that time the transmission is maintained at its minimum ratio by the torque applied to it via the starting device. The present invention can also be realized as the following forms.
[Form 1]
Rotational input connectable to a rotational driver, rotational output connectable to a vehicle wheel, a variator coupled between the rotational input and the rotational output to provide a continuously variable drive ratio, and the rotational input And a starter configured to selectively couple / decouple the rotational output, and the variator is configured and arranged to provide the required torque, the starter providing the required torque capacity A continuously variable vehicle transmission configured and arranged as follows:
A continuously variable transmission having a control configuration in which the same control signal is applied to a variator for setting a required torque and to a starting device for setting its torque capacity.
[Form 2]
The continuously variable transmission according to mode 1, wherein the variator and the starting device are configured such that the torque capacity of the clutch always exceeds the output torque provided by the variator.
[Form 3]
The continuously variable transmission according to mode 1 or 2, wherein the control signal is a hydraulic pressure.
[Form 4]
The continuously variable transmission according to any one of aspects 1 to 3, wherein the starting device includes a clutch or a brake.
[Form 5]
The continuously variable transmission according to claim 3, wherein the hydraulic pressure is applied to a hydraulic actuator of a variator to determine a force applied to a movable torque transmitting portion of the variator.
[Form 6]
The variator has a movable roller that moves on a pair of races to transmit torque from one to the other, and a hydraulic actuator is coupled to the roller to exert a force on the roller, and the hydraulic pressure applies the force described above. A continuously variable transmission according to mode 3, which is applied to a hydraulic actuator for determination.
[Form 7]
The variator further includes a traction load device coupled to one of the pair of races for transmitting torque to the race, and applying the traction load determined by the torque transmitted by the traction load device to the race. A continuously variable transmission according to mode 1, wherein the continuously variable transmission is configured and arranged as described above.
[Form 8]
The traction load device has first and second portions mounted for rotation about a common axis, the first and second portions having one axial displacement with respect to the other and one axial displacement with respect to the other. The continuously variable transmission according to aspect 7, wherein the continuously variable transmission is configured to generate
[Form 9]
Defines toroidal variator cavities together and moves on at least one pair of partially toroidally recessed races mounted for rotation on a common variator axis and partially toroidally recessed races And at least two rollers positioned between the races so as to transmit the driving force with a variator drive ratio, and the rollers can be tilted to change the tilt of the roller axis with respect to the variator axis. A variator that is mounted in a way that allows a stepless change in the ratio,
Via a mechanical traction load structure that helps one of the races transmit torque between the connecting shaft and the variator race and impart a traction load force that is a function of the transmitted torque to the race, Coupled to the connecting shaft, it presses the variator race so that the traction load force engages the roller to provide the traction required to transmit the driving force, and the variator limits the tilt of the roller. A variator having a contact portion.
[Mode 10]
The traction load device has first and second portions mounted for rotation about a common axis, the first and second portions having one axial displacement with respect to the other and one axial displacement with respect to the other. The variator of form 9, wherein the variator is shaped to produce
[Form 11]
At least one cam surface on which the first portion of the traction load device extends circumferentially and is inclined with respect to a radial plane; and at least one follower that rides on the cam surface and contacts the second portion The variator according to aspect 10, characterized by comprising:
[Form 12]
The roller is operatively coupled to a hydraulic piston / cylinder structure and the mechanical abutment is positioned to abut the piston so as to limit its travel and limit the tilt of the roller. The variator according to any one of forms 9 to 11.
[Form 13]
Rotational input connectable to a rotational driver, rotational output connectable to a vehicle wheel, a variator coupled between the rotational input and rotational output to provide a stepless change in drive ratio, and rotational input And a continuously variable vehicle transmission having a starter configured to selectively couple / decouple the rotational output comprising:
Control the variator to provide the desired reaction force torque and tune the variator reaction torque so that the torque applied to the starter by the variator is always less than the torque capacity of the starter And controlling the torque capacity of the starting device.
[Form 14]
The method of aspect 13, comprising the step of applying the same control signal to the variator and the starting device.
[Form 15]
It has a step of managing the starting device by gradually increasing the reaction force torque of the variator and the torque capacity of the starting device, and the torque capacity of the starting device is applied by the variator until there is no slippage of the starting device. The method of embodiment 13 or 14, characterized in that the torque is always exceeded, so that until that time, the transmission is maintained at its minimum ratio by the torque applied via the starting device.

Claims (15)

Rotational input connectable to a rotational driver, rotational output connectable to a vehicle wheel, a variator coupled between the rotational input and the rotational output to provide a continuously variable drive ratio, and the rotational input And a starter configured to selectively couple / decouple the rotational output, and the variator is configured and arranged to provide the required torque, the starter providing the required torque capacity A continuously variable vehicle transmission configured and arranged as follows:
A continuously variable transmission having a control configuration in which the same control signal is applied to a variator for setting a required torque and to a starting device for setting its torque capacity. 2. The continuously variable transmission according to claim 1, wherein the variator and the starting device are configured such that the torque capacity of the clutch always exceeds the output torque provided by the variator.   3. The continuously variable transmission according to claim 1, wherein the control signal is a hydraulic pressure. 4. The continuously variable transmission according to claim 1, wherein the starting device has a clutch or a brake. 4. A continuously variable transmission according to claim 3, wherein said hydraulic pressure is applied to a hydraulic actuator of a variator to determine a force applied to a movable torque transmitting portion of the variator. The variator has a movable roller that moves on a pair of races to transmit torque from one to the other, and a hydraulic actuator is coupled to the roller to exert a force on the roller, and the hydraulic pressure applies the force described above. 4. The continuously variable transmission according to claim 3, wherein the continuously variable transmission is applied to a hydraulic actuator to determine. The variator further includes a traction load device coupled to one of the pair of races for transmitting torque to the race, and applying the traction load determined by the torque transmitted by the traction load device to the race. 2. The continuously variable transmission according to claim 1, wherein the continuously variable transmission is configured and arranged. The traction load device has first and second portions mounted for rotation about a common axis, the first and second portions having one axial displacement with respect to the other and one axial displacement with respect to the other. The continuously variable transmission according to claim 7, wherein the continuously variable transmission is configured to generate Defines toroidal variator cavities together and moves on at least one pair of partially toroidally recessed races mounted for rotation on a common variator axis and partially toroidally recessed races And at least two rollers positioned between the races so as to transmit the driving force with a variator drive ratio, and the rollers can be tilted to change the tilt of the roller axis with respect to the variator axis. A variator that is mounted in a way that allows a stepless change in the ratio,
Via a mechanical traction load structure that helps one of the races transmit torque between the connecting shaft and the variator race and impart a traction load force that is a function of the transmitted torque to the race, Coupled to the connecting shaft, it presses the variator race so that the traction load force engages the roller to provide the traction required to transmit the driving force, and the variator limits the tilt of the roller. A variator having a contact portion. The traction load device has first and second portions mounted for rotation about a common axis, the first and second portions having one axial displacement with respect to the other and one axial displacement with respect to the other. 10. The variator of claim 9, wherein the variator is shaped to produce At least one cam surface on which the first portion of the traction load device extends circumferentially and is inclined with respect to a radial plane; and at least one follower that rides on the cam surface and contacts the second portion 11. The variator of claim 10, comprising: The roller is operatively coupled to a hydraulic piston / cylinder structure and the mechanical abutment is positioned to abut the piston so as to limit its travel and limit the tilt of the roller. The variator according to any one of claims 9 to 11. Rotational input connectable to a rotational driver, rotational output connectable to a vehicle wheel, a variator coupled between the rotational input and rotational output to provide a stepless change in drive ratio, and rotational input And a continuously variable vehicle transmission having a starter configured to selectively couple / decouple the rotational output comprising:
Control the variator to provide the desired reaction force torque and tune the variator reaction torque so that the torque applied to the starter by the variator is always less than the torque capacity of the starter And controlling the torque capacity of the starting device. 2. The method of applying the same control signal to the variator and the starting device.
Method 3. It has a step of managing the starting device by gradually increasing the reaction force torque of the variator and the torque capacity of the starting device, and the torque capacity of the starting device is applied by the variator until there is no slippage of the starting device. 15. A method according to claim 13 or 14, characterized in that the torque is always exceeded so that, until that point, the transmission is maintained at its minimum ratio by the torque applied via the starting device.

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