JP2005195111A - Power transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission system capable of improving starting capability of a vehicle at a bad road and escaping capability from the bad road. <P>SOLUTION: The power transmission system comprises a differential mechanism 43 distributing driving force of an engine 3 to left and right wheels 19 and 21, and a coupling limiting differential rotation between the wheels 19 and 21. The coupling is a rotation-sensing type or torque-sensing type differential motion limiting means, and the coupling and a connecting and disconnecting device of driving force are arranged in series between the differential mechanism and one of the left and right wheels. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a power transmission device that improves the escape performance and running performance of a vehicle on, for example, a rough road.

Japanese Patent Application Laid-Open No. H10-228561 describes a differential device. This differential device is disposed on the front wheel side or the rear wheel side that is separated during two-wheel drive in a four-wheel drive vehicle. It consists of a differential case, a differential mechanism connected to the inner differential case, a dog clutch that intermittently connects the outer differential case and the inner differential case, and an actuator that intermittently operates the dog clutch. The force is distributed from the differential mechanism to the left and right wheels so that the vehicle is in a four-wheel drive state, and when the dog clutch is disengaged, the separation-side wheel is disconnected and the vehicle is in a two-wheel drive state.
JP 2002-213573 A (FIG. 1)

  The four-wheel drive vehicle is set to a four-wheel drive state in order to improve escape and running performance on rough roads.

  However, for example, in the case of an FR-based four-wheel drive vehicle, even if the space between the front wheels and the rear wheels is rigid, the left and right rear wheels run idle on a rough road, and if one of the front wheels runs idle, Due to the differential rotation of the differential device, the torque is lost from the idle front wheel, so that the driving force of the engine is not transmitted to the other front wheel, and as a result, the vehicle may not be able to escape from the rough road.

  Accordingly, an object of the present invention is to provide a power transmission device that improves vehicle startability, rough road escape performance, and the like on rough roads.

  The power transmission device according to claim 1 includes a differential mechanism that distributes the driving force of the prime mover to the left and right wheels, and a coupling that limits differential rotation between the wheels.

  The invention according to claim 2 is the power transmission device according to claim 1, wherein the coupling is a differential limiting means of rotation difference sensitive type.

  The invention of claim 3 is the power transmission device according to claim 1, wherein the coupling is a torque-sensitive differential limiting means.

  The invention according to claim 4 is the power transmission device according to any one of claims 1 to 3, wherein the coupling and the driving force are between the differential mechanism and the left or right wheel. The intermittent device is arranged in series.

  The invention according to claim 5 is the power transmission device according to claim 4, wherein the coupling and the driving force interrupting device are integrally provided.

  The power transmission device according to the present invention includes the coupling for limiting the differential rotation between the wheels as in the configuration of the first aspect, so that even if one of the left and right wheels idles on a rough road, the coupling With this differential limiting function, the driving force of the prime mover is reliably transmitted to the road surface from the wheels on the other side, and the vehicle startability and rough road escape properties are kept high, thereby preventing the stacking.

  In the power transmission device according to the second aspect, the coupling is a differential limiting means whose rotational difference is sensitive, and an effect equivalent to that of the first aspect can be obtained.

  In the power transmission device according to the third aspect, the coupling is a torque-sensitive differential limiting means, and the same effect as that of the first aspect can be obtained.

  In the power transmission device according to the fourth aspect of the present invention, when the driving force interrupting device is connected, the coupling is activated, and the effect equivalent to that of the first to third embodiments can be obtained by the differential limiting function.

  The power transmission device according to claim 5 has the same effect as the configuration of claim 4, and is configured to be small and light by providing the coupling and the driving force interrupting device integrally (unitized). It is excellent in in-vehicle performance.

(First embodiment)
The power transmission device 1 (first embodiment of the present invention) will be described with reference to FIG. FIG. 1 is a skeleton mechanism diagram showing a power transmission device 1 and a power system of a four-wheel drive vehicle using the same. In the following description, the left and right directions are the left and right directions of the four-wheel drive vehicle, and members and the like that are not given reference numerals are not shown.

[Configuration of Power Transmission Device 1]
The power transmission device 1 includes a differential mechanism 43 that distributes the driving force of the engine 3 (prime mover) to the left and right front wheels 19 and 21, and a coupling 45 that restricts differential rotation between the front wheels 19 and 21 (rotational difference sensitive). Type differential limiting means).

[Configuration of power system of a four-wheel drive vehicle using the power transmission device 1]
This power system includes a longitudinal engine 3 (prime mover), a transmission 5 and a transfer 7, a 2-4 switching mechanism 9 constituting a part of the transfer 7, a front wheel side propeller shaft 11, and a front differential 13 (prime mover). ), Front axles 15 and 17, left and right front wheels 19 and 21, rear wheel propeller shaft 23, and rear differential 25 (the driving force of the prime mover on the left and right rear wheels). Differential device), rear axles 27, 29, left and right rear wheels 31, 33, a controller, and the like.

  The 2-4 switching mechanism 9 constitutes the transfer 7 together with the chain transmission mechanism 35. The output shaft 37 of the transmission 5 and the chain transmission mechanism 35 are intermittently connected to the propeller shaft 23 on the rear wheel side. 3, the chain transmission mechanism 35 transmits the driving force to the propeller shaft 11 on the front wheel side.

  The front differential 13 includes an outer differential case 39 that rotates in response to the driving force of the engine 3, an inner differential case 41 that is relatively rotatably disposed within the outer differential case 39, and a bevel gear type differential coupled to the inner differential case 41. A mechanism 45, a coupling 45 that limits the differential of the differential mechanism 43, a meshing clutch 47 that intermittently connects the outer differential case 39 and the inner differential case 41, an electromagnetic actuator 49 that meshes the meshing clutch 47, and an electromagnetic actuator 49 When stopped, the clutch comprises a return spring that releases the engagement of the meshing clutch 47, and a controller that operates the electromagnetic actuator 49 to connect and disconnect the meshing clutch 47.

  A ring gear 51 is fixed to the outer differential case 39, and the ring gear 51 meshes with a drive pinion gear 53 connected to the propeller shaft 11 side of the front wheel. The differential mechanism 43 includes output side gears 55 and 57 connected to the left and right front axles 15 and 17, respectively.

  The coupling 45 is a differential limiting unit that obtains a rotation differential-sensitive differential limiting function by shear resistance of a viscous fluid, and oil that limits differential rotation between differential rotary members based on the discharge pressure resistance of the oil pump. A pump system is employed and is disposed between the side gears 55 and 57 of the differential mechanism 43.

  When the vehicle travels on four wheels, the controller connects the 2-4 switching mechanism 9 of the transfer 7, and the front differential 13 operates the electromagnetic actuator 49 to connect the meshing clutch 47. The driving force of the engine 3 input from the transmission 5 to the transfer 7 is transmitted from the propeller shaft 23 to the rear differential 25 via the output shaft 37, and from the rear differential 25 to the left and right rear wheels 31, 33 via the rear axles 27, 29. The 2-4 switching mechanism 9, the chain transmission mechanism 35, and the propeller shaft 11 are rotated, and the drive pinion gear 53, the ring gear 51, the outer differential case 39, the meshing clutch 47, and the inner differential case 41 are rotated. Via the side gears 55 and 57 and the front axles 15 and 17 to the left and right front wheels 19 and 21.

  Further, when a driving resistance difference occurs between the front wheels 19 and 21 or between the rear wheels 31 and 33 while traveling on a rough road, the engine 3 is driven by the distribution function to the front differential 13 and the rear differential 25. The force is differentially distributed to the front wheels 19 and 21 and the rear wheels 31 and 33, respectively. At this time, even if one of the front wheels 19 and 21 slips, the driving force is sent to the other of the front wheels 19 and 21 by the differential limiting function of the coupling 45, and the rough road escape performance and running performance of the vehicle are improved. .

  Further, even when the rear wheels 31 and 33 are idled during starting or acceleration, the slip between the front wheels 19 and 21 is suppressed by the differential limiting function of the coupling 45, and the driving force is reliably transmitted to the road surface. Acceleration is improved, driving force loss is reduced, and fuel efficiency is improved.

  Further, as described above, the coupling 45 is arranged between the side gears 55 and 57 (SS arrangement), and when the same rotational speed differential occurs between the front wheels 19 and 21, the coupling 45 is connected to the inner side. Compared with the case where the differential case 41 and one of the side gears 55 and 57 are arranged (HS arrangement), since the differential rotational speed is doubled, a larger differential limiting function can be obtained.

  Further, when the vehicle travels on a two-wheel drive, the controller releases the connection of the 2-4 switching mechanism 9 and stops the electromagnetic actuator 49, thereby releasing the engagement of the engagement clutch 47 by the return spring. It becomes a two-wheel drive state of wheel drive. At this time, the inner differential case 41 to the front wheels 19 and 21 are in a free rotating state, and the 2-4 switching mechanism 9 to the outer differential case 39 of the front differential 13 are separated from the driving force of the engine 3 and the rotation of the front wheels 19 and 21. This prevents rotation and reduces vibration and noise and improves fuel efficiency.

  In addition, the coupling 45 can alleviate the impact caused by the meshing of the side gears 55 and 57 and the pinion 56 due to the differential rotation between the front wheels 19 and 21 when the vehicle is in a two-wheel drive state. It arrange | positions between a pair of side gears. In addition, by arranging the rotation-sensitive coupling 45 on the front wheel side, when the vehicle is in a two-wheel drive state, the rolling of the outer wheel of the left and right wheels can be restricted by the inner wheel, and the vehicle overload Steer (moment in the rotational direction) can be suppressed.

[Effect of power transmission device 1]
The power transmission device 1 includes the coupling 45 that restricts differential rotation between the front wheels 19 and 21, so that, for example, the rear wheels 31 and 33 are idled when starting or on a rough road. Even if one of the wheels 21 is idling, the differential limiting function of the coupling 45 ensures that the driving force of the engine 3 is reliably transmitted from the other front wheels 19 and 21 to the road surface, and the vehicle has high startability, escape performance, running performance, etc. Thus, stacking is prevented, loss of driving force is reduced, and fuel efficiency is improved.

(Second Embodiment)
The power transmission device 101 (second embodiment of the present invention) will be described with reference to FIG. The power transmission device 101 is used in place of the power transmission device 1 in a vehicle having the same configuration as that of FIG. 1. Hereinafter, members having the same functions as those of the power transmission device 1 are given the same reference numerals, and are cited. Differences from the power transmission device 1 will be described.

[Configuration of Power Transmission Device 101]
The power transmission device 101 includes a differential mechanism 43 that distributes the driving force of the engine 3 to the left and right front wheels 19 and 21, and a coupling 103 that restricts differential rotation between the front wheels 19 and 21 (rotational difference-sensitive difference). Motion limiting means).

  The coupling 103 is a differential limiting unit that obtains a rotation differential type differential limiting function by the shear resistance of the viscous fluid, and is disposed between the inner differential case 41 and the right side gear 57 of the differential mechanism 43 so that the vehicle is Even if one of the front wheels 19 and 21 slips while traveling on a rough road or the like, a driving force is sent to the other of the front wheels 19 and 21 due to the differential limiting function, thereby improving the vehicle's ability to escape on rough roads and driving performance. .

  Further, even when the rear wheels 31 and 33 are idled when starting or accelerating, the differential limiting function of the coupling 103 suppresses the slip between the front wheels 19 and 21, and the driving force is reliably transmitted to the road surface. Acceleration is improved, driving force loss is reduced, and fuel efficiency is improved.

  In addition, the coupling 45 can alleviate the impact caused by the meshing of the side gears 55 and 57 and the pinion 56 due to the differential rotation between the front wheels 19 and 21 when the vehicle is in a two-wheel drive state. It is disposed between the inner differential case 41 and the side gear 57. In addition, by arranging the rotation-sensitive coupling 45 on the front wheel side, when the vehicle is in a two-wheel drive state, the rolling of the outer wheel of the left and right wheels can be restricted by the inner wheel, and the vehicle overload Steer (moment in the rotational direction) can be suppressed.

[Effect of power transmission device 101]
The power transmission device 101 includes the coupling 103 that restricts differential rotation between the front wheels 19 and 21, so that, for example, the rear wheels 31 and 33 are idled when starting or on a rough road. Even if one of the wheels 21 is idling, the differential limiting function of the coupling 45 ensures that the driving force of the engine 3 is reliably transmitted from the other front wheels 19 and 21 to the road surface, and the vehicle has high startability, escape performance, running performance, etc. Thus, stacking is prevented and loss of driving force is reduced to improve fuel efficiency.

(Third embodiment)
A power transmission device 201 (a third embodiment of the present invention) will be described with reference to FIG. FIG. 3 is a skeleton mechanism diagram showing a power transmission device 201 and a power system of a four-wheel drive vehicle using the same. In the following, differences from the power transmission device 1 will be described with reference to the vehicle and the power transmission device 1 shown in FIG.

[Configuration of Power Transmission Device 201]
The power transmission device 201 includes a differential mechanism 43 that distributes the driving force of the engine 3 to the left and right front wheels 19 and 21, and a coupling 203 that restricts differential rotation between the front wheels 19 and 21 (rotation difference-sensitive difference). Motion limiting means) and a driving force interrupting device 205 (axle disconnect mechanism: ADD mechanism) which is arranged in series with the coupling 203 and exposed to the atmosphere side and is integrated with the coupling 203. ing.

[Configuration of power system of four-wheel drive vehicle using power transmission device 201]
This power system includes an engine 3, a transmission 5, a transfer 7, a 2-4 switching mechanism 9 constituting a part of the transfer 7, a propeller shaft 11 on the front wheel side, a front differential 207, a front axle 15, 17, coupling 203 and interrupting device 205, left and right front wheels 19 and 21, rear wheel propeller shaft 23, rear differential 25, rear axles 27 and 29, left and right rear wheels 31 and 33, controller The front differential 207 includes a differential case 209 that rotates in response to the driving force of the engine 3 and a differential mechanism 43 connected to the differential case 209.

  The coupling 203 is a differential limiting unit that obtains a rotation differential type differential limiting function by the shear resistance of the viscous fluid. Further, a pair of separated axles 211 and 213 are disposed between the right side gear 57 of the differential mechanism 43 and the axle 17, and the intermittent device 205 moves the shift fork 217 and the shift sleeve 219 by the actuator 215. By operating, the coupling 203 is intermittently connected to the axles 211 and 213.

  When the vehicle travels on four wheels, the controller connects the 2-4 switching mechanism 9 of the transfer 7 and also connects the interrupting device 205 by the actuator 215 to enable the coupling 203. The driving force of the engine 3 is distributed from the output shaft 37, the propeller shaft 23, and the rear differential 25 to the rear wheels 31, 33, and from the 2-4 switching mechanism 9, the chain transmission mechanism 35, the propeller shaft 11, and the gears 53, 57. It is transmitted to the front differential 207 and distributed to the front wheels 19 and 21.

  Further, when a driving resistance difference occurs between the front wheels 19 and 21 and between the rear wheels 31 and 33 during traveling on a rough road, the driving force of the engine 3 is changed from the front differential 207 and the rear differential 25 to the front wheels 19 and 21 and the rear wheels. 31 and 33, respectively. At this time, even if one of the front wheels 19 and 21 idles, the driving force is sent to the other of the front wheels 19 and 21 by the differential limiting function of the coupling 203, and the rough road escape performance and running performance are improved.

  Further, even when the rear wheels 31 and 33 are idled at the time of starting or accelerating, slip between the front wheels 19 and 21 is suppressed by the differential limiting function of the coupling 203, and the driving force is reliably transmitted to the road surface. Acceleration is improved, driving force loss is reduced, and fuel efficiency is improved.

  When the vehicle travels on two wheels, the controller releases the connection between the 2-4 switching mechanism 9 and the interrupting device 205. When the connection of the interrupting device 205 is released, the driving force is not transmitted to any of the front wheels 19 and 21 due to the idling of the differential mechanism 43, and the vehicle enters a two-wheel drive state of rear wheel drive.

[Effect of power transmission device 201]
The power transmission device 201 includes a coupling 203 that restricts differential rotation between the front wheels 19 and 21, so that, for example, the rear wheels 31 and 33 are idled when starting or on a rough road. Even if one of the wheels 21 is idling, the differential limiting function of the coupling 45 ensures that the driving force of the engine 3 is reliably transmitted from the other front wheels 19 and 21 to the road surface, and the vehicle has high startability, escape performance, running performance, etc. Thus, stacking is prevented and loss of driving force is reduced to improve fuel efficiency.

  Further, since the coupling 203 and the interrupting device 205 are unitized, it is configured to be small and light, and the in-vehicle performance is improved accordingly. Moreover, this unitization can avoid changes in the member shape and support structure on the front differential side. Further, by disposing the coupling so as to be exposed to the outside, the cooling performance by the outside air is improved, and the deterioration of the coupling function due to the high temperature state can be prevented.

  The coupling 203 and the interrupting device 205 may be arranged separately in series between any one of the front wheels 19 and 21 and the differential mechanism 43 without being unitized.

  Further, the coupling 203 may be provided on any of the hubs 221 and 223 of the front wheels 19 and 21.

(Fourth embodiment)
A power transmission device 301 (a fourth embodiment of the present invention) will be described with reference to FIG.

  The power transmission device 301 includes a power system 305 on the front wheel side as a main drive wheel that uses an engine 303 as a main drive power source as a prime mover, and a sub drive wheel that uses an electric motor 307 as a sub drive source as a prime mover. It is used in the rear wheel side power system 309 of the hybrid four-wheel drive vehicle constituted by the wheel side power system 309. The left and right directions are the left and right directions of the four-wheel drive vehicle.

[Configuration of Power Transmission Device 301]
The power transmission device 301 includes a differential mechanism 43 that distributes the driving force of the electric motor 307 (prime mover) to the left and right rear wheels 343 and 345 and a coupling 353 that restricts differential rotation between the rear wheels 343 and 345 ( It is composed of a rotation difference sensitive differential limiting means).

[Configuration of the hybrid four-wheel drive vehicle using the power transmission device 301]
The power system 305 on the front wheel side includes a horizontally installed engine 303 and transmission 311, a front differential 313 as a main drive side differential device, front axles 315 and 317, left and right front wheels 319 and 321, and the like. The driving force of the engine 303 is transmitted from the transmission 311 to the front differential 313 and distributed to the left and right front wheels 319 and 321 via the front axles 315 and 317.

  The rear-wheel-side power system 309 includes three reduction gear sets 323, 325, and 327, an intermittent mechanism 329, a rear differential 331 as a sub-drive-side differential device, an electric motor 307, a battery 333, and a sensor 335. And a controller 337, rear axles 339 and 341, left and right rear wheels 343 and 345, and the like.

  The reduction gear sets 323, 325, and 327 reduce the driving force of the electric motor 307 in three stages, and the intermittence mechanism 329 includes a multi-plate clutch 347 and an electromagnetic actuator 349 that intermittently operates the decelerating gear set 325 and the reduction gear set 325. The driving force is intermittently connected to the gear set 327.

  The rear differential 331 includes a differential case 351, a differential mechanism 43 connected to the differential case 351, and a coupling 353 that limits the differential of the differential mechanism 43. The coupling 353 is a differential limiting unit that obtains a rotation differential type differential limiting function by the shear resistance of the viscous fluid, and is disposed between the differential case 351 of the differential mechanism 43 and the left side gear 55.

  When the intermittent mechanism 329 is connected, the driving force of the electric motor 307 is decelerated by the reduction gear sets 323, 325, 327 to the traveling rotational speed range of the wheels (rear wheels 343, 345), and the torque is amplified to the rear differential 331. It is transmitted and distributed from the rear axles 339 and 341 to the left and right rear wheels 343 and 345.

  Based on the information from the sensor 335, the controller 337 performs driving of the electric motor 307, adjustment of the rotational speed, stop of driving, and intermittent operation of the multi-plate clutch 347 (interrupt mechanism 329) by the electromagnetic actuator 349 based on information from the sensor 335. The battery is charged by an electric generator attached to the engine or rotated from the rear wheels 343 and 345 when the vehicle is decelerated through the reduction gear sets 323, 325 and 327 and the multi-plate clutch 347. By being collected by the generator action of 307.

  During normal travel, the controller 337 stops driving the electric motor 307 and interrupts the driving force by the intermittent mechanism 329 to stop the operation of the rear wheel side power system 309 and drives the front wheels 319 and 321 with the engine 303. Then, the vehicle is brought into a two-wheel drive state by the front wheel side power system 305.

  In addition, when securing driving force as a vehicle, that is, four-wheel drive or rear-wheel drive is required, the electric motor 307 is driven and the intermittent mechanism 329 is connected to operate the rear-wheel side power system 309, and the rear The wheels 343 and 345 are driven auxiliary to bring the vehicle into a four-wheel drive state or a rear wheel drive state. The driving force of the front wheels 319 and 321 and the rear wheels 343 and 345 is ensured while traveling on a rough road or the like in such a driving state, and an optimal driving state as a vehicle can be obtained.

  At this time, even if one of the rear wheels 343, 345 slips, the driving force is sent to the other of the rear wheels 343, 345 by the differential limiting function of the coupling 353, and the rough road escape performance and running performance of the vehicle are improved. .

  Further, even when the front wheels 319 and 321 are idled at the time of starting or accelerating, the differential limiting function of the coupling 353 suppresses the slip of the rear wheels 343 and 345, so that the driving force of the electric motor 307 is reliably transmitted. Power loss is reduced and power consumption loss is improved.

  Further, the coupling 353 is configured to generate a rattling sound between the side gears 55 and 57 of the differential mechanism 329 of the rear differential 331 and the pinion 56 between the rear wheels 343 and 345 when the vehicle is in the front wheel driving state and the two wheel driving state. It acts to reduce the generated impact.

[Effect of power transmission device 301]
Since the power transmission device 301 is configured as described above, the following effects can be obtained.

  The power transmission device 301 includes a coupling 353 that restricts differential rotation between the rear wheels 343 and 345, so that, for example, the front wheels 319 and 321 idle on a start or a rough road, and the rear wheels 343 , 345 even if one of the wheels rotates idly, the driving force of the electric motor 307 is reliably transmitted from the other rear wheels 343, 345 to the road surface, and the startability, escape performance, running performance, etc. of the vehicle are kept high, and the stack is Is prevented.

[Other Embodiments Included within the Scope of the Present Invention]
In the power transmission device of the present invention, the coupling is not limited to the rotation-difference-sensitive differential limiting means as used in each embodiment, but may be another coupling mechanism having a rotation-difference-sensitive function, Torque sensitive differential limiting means or differential limiting means of operating a friction clutch with an actuator may be used. Further, as a driving form of the vehicle, there can be various vehicle forms having a main driving wheel side and a sub driving wheel side such as an RR base, an MR base, and an MF base.

  Further, unlike the embodiments, the power transmission device of the present invention can be applied to a four-wheel drive vehicle using a center differential to obtain the same effect.

It is a skeleton mechanism figure which shows the motive power system of the four-wheel drive vehicle using the power transmission device 1 of 1st Embodiment. It is a skeleton mechanism figure which shows the motive power system of the four-wheel drive vehicle using the power transmission device 101 of 2nd Embodiment. It is a skeleton mechanism figure which shows the motive power system of the four-wheel drive vehicle using the power transmission device 201 of 3rd Embodiment. It is a skeleton mechanism figure which shows the motive power system of the four-wheel drive vehicle using the power transmission device 301 of 4th Embodiment.

Explanation of symbols

1 Power transmission device 3 Engine (motor)
19, 21 Front wheel
43 Differential mechanism 45 Coupling (rotational difference sensitive differential limiting means)
101 Power transmission device 103 Coupling (rotational difference sensitive differential limiting means)
201 Power transmission device 203 coupling (rotational difference sensitive differential limiting means)
205 Driving force interrupting device 301 arranged in series with coupling 203 and integrally configured Power transmission device 307 Electric motor (prime mover)
343,345 Rear wheels (wheels)
353 Coupling (rotational difference sensitive differential limiting means)

Claims (5)

A differential mechanism that distributes the driving force of the prime mover to the left and right wheels;
A power transmission device comprising a coupling for limiting differential rotation between the wheels. The invention according to claim 1,
The power transmission device according to claim 1, wherein the coupling is a rotation-sensitive type differential limiting means. The invention according to claim 1,
The power transmission device, wherein the coupling is a torque-sensitive differential limiting means. The invention according to any one of claims 1 to 3,
The power transmission device, wherein the coupling and the driving force interrupting device are arranged in series between the differential mechanism and one of the left and right wheels. The invention according to claim 4,
The power transmission device, wherein the coupling and the driving force interrupting device are integrally provided.

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