CN110725876A - Centrifugal speed-increasing liquid inlet system for hydraulic retarder - Google Patents

Abstract

The invention relates to the technical field of vehicle retarding braking, in particular to a centrifugal speed-increasing liquid inlet system for a hydraulic retarder. The system comprises a partition board coaxially and fixedly connected to the liquid inlet end of a front end cover of the hydraulic retarder, wherein a pump cover covers the outer side surface of the partition board, so that a cavity formed by enclosing the pump cover and the partition board forms a pump cavity for arranging a centrifugal impeller, and a transmission shaft of the hydraulic retarder coaxially penetrates through the partition board and then forms a fixedly connected fit relation with the centrifugal impeller; a pore passage axially penetrates through the pump cover to form a liquid inlet flow passage communicated with the inlet end of the centrifugal impeller in the pump cavity; the baffle is axially provided with a communicating hole in a penetrating way, so that the outlet end of the centrifugal impeller in the pump cavity is communicated with the retarding cavity of the hydraulic retarder. The centrifugal speed-increasing retarder has the advantages of low cost, compact structure and convenience in installation, and can skillfully utilize the self-power of the transmission shaft to provide a centrifugal speed-increasing structure to drive power, so that the problems of low working liquid backflow and liquid inlet flow speed when the traditional hydraulic retarder works are effectively solved.

Description

Centrifugal speed-increasing liquid inlet system for hydraulic retarder

Technical Field

The invention relates to the technical field of vehicle retarding braking, in particular to a centrifugal speed-increasing liquid inlet system for a hydraulic retarder.

Background

When the vehicle is continuously braked for a long time, is braked at high intensity or is frequently braked, the temperature of a brake disc or a brake drum is greatly increased, so that the friction factor is reduced, the abrasion degree is increased, and the dangerous heat fading phenomenon that the braking efficiency is partially or even completely lost occurs. Although the application of an anti-lock braking system (ABS), an electronic brake force distribution system (EBD), and the like, improves the stability and reliability of vehicle braking, they have little effect on improving the heat fade phenomenon of the brakes. At present, many countries including China clearly stipulate that passenger cars and heavy-duty trucks with more than a certain specification must be provided with auxiliary braking devices so as to effectively shunt the load of a brake and improve the braking safety performance of the vehicle. The hydraulic retarder is one of vehicle auxiliary brake devices, and mainly comprises two types, namely a hydraulic retarder and an eddy current retarder. In foreign countries, the hydraulic retarder basically replaces an eddy current retarder due to the advantages of large braking torque, low energy consumption, good reliability and the like; in China, the eddy current retarder is still the leading product, but the rapid development of the hydraulic retarder becomes an inevitable trend.

The hydraulic retarder, also known as a hydraulic retarder, is an effective auxiliary braking device for vehicles. The hydrodynamic retarder can obtain the best retarding combination by working together with the engine retarding. Because the hydrodynamic retarder is provided with an oil supply system, a large amount of kinetic energy of the vehicle can be converted into heat energy in the shortest time, and the heat energy is dissipated through a cooling system of the engine, so that the hydrodynamic retarder has no overheating problem, and can keep the thermal state of the engine in the process of descending a long slope of the vehicle, thereby saving fuel and protecting the engine. Because the hydraulic retarder utilizes the cooling system heat dissipation of engine, can not increase the heat load of engine, and the retarding moment can not descend along with the temperature rising, consequently can keep stable retarding ability again, and this makes hydraulic retarder still keep the slow down effect in the twinkling of an eye of shifting, and the slow down effect is continuous to very big improvement the security of traveling. On the premise of having such many advantages, the disadvantages of the hydrodynamic retarder are quite obvious: on one hand, as the liquid inlet pipeline of the hydraulic retarder is directly connected to an external hydraulic source, the possibility of liquid return exists during working, and the actual braking effect can be influenced. On the other hand, the hydraulic retarder has small braking torque at low speed, and can not meet the braking requirement. In addition, during actual braking, working fluid needs a certain time to enter the retarding cavity, namely the fluid inlet speed is relatively slow, so that the braking response time is long, and the popularization and the application of the conventional hydrodynamic retarder are greatly restricted.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a centrifugal speed-increasing liquid inlet system for a hydraulic retarder. The centrifugal speed-increasing retarder has the advantages of low cost, compact structure and convenience in installation, and can skillfully utilize the self-power of the transmission shaft to provide a centrifugal speed-increasing structure to drive power, so that the problems of low working liquid backflow and liquid inlet flow speed when the traditional hydraulic retarder works are effectively solved.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a centrifugal acceleration rate feed liquor system for hydraulic retarder which characterized in that: the system comprises a partition board coaxially and fixedly connected at the liquid inlet end of a front end cover of the hydraulic retarder, wherein one side surface of the partition board facing the front end cover is taken as an inner side surface, a pump cover covers the outer side surface of the partition board, so that a cavity formed by enclosing the pump cover and the partition board forms a pump cavity for arranging a centrifugal impeller, and a transmission shaft of the hydraulic retarder coaxially penetrates through the partition board and then forms a fixedly connected fit relation with the centrifugal impeller; a pore passage axially penetrates through the pump cover to form a liquid inlet flow passage communicated with the inlet end of the centrifugal impeller in the pump cavity; the baffle is axially provided with a communicating hole in a penetrating way, so that the outlet end of the centrifugal impeller in the pump cavity is communicated with the retarding cavity of the hydraulic retarder.

Preferably, the communication holes are round holes, and the communication holes form a group; the distance between the communicating hole and the axis of the transmission shaft is larger than or equal to the distance between the top edge of the impeller blade of the centrifugal impeller and the axis of the transmission shaft.

Preferably, the liquid inlet end cavity of the front end cover is provided with a fillet so as to form a drainage cavity channel capable of smoothly draining with the rotor of the hydraulic retarder and the inner side surface of the partition plate, the drainage cavity channel is in the shape of an annular cavity coaxial with the transmission shaft, one end of the drainage cavity channel is connected with the communicating hole, and the other end of the drainage cavity channel is communicated with the retarding cavity of the hydraulic retarder.

Preferably, the centrifugal impeller is constrained from circumferential movement relative to the drive shaft by a keyed connection, and is constrained from axial movement relative to the drive shaft by clamping the centrifugal impeller by engagement of a cap nut with a shoulder.

Preferably, an oil seal ring is arranged at a gap between the partition plate and the shaft body of the transmission shaft.

Preferably, the fastening screw axially penetrates through the pump cover and the partition plate in sequence and is fixedly connected to the end face of the liquid inlet end of the front end cover in a threaded manner, and an O-shaped ring for sealing a gap between the pump cover and the partition plate is arranged between the pump cover and the partition plate.

The beneficial effect of above-mentioned scheme lies in:

1) on the basis of the inherent structure of the existing hydrodynamic retarder, a partition plate with a communicating hole and a pump cover with a pore passage are sequentially and axially added at the liquid inlet end of a front end cover of the hydrodynamic retarder, and a centrifugal impeller is arranged in a pump cavity enclosed by the pump cover and the partition plate, so that the pump cover, the partition plate and the centrifugal impeller are combined to form a centrifugal pump type speed-increasing liquid inlet mechanism. When the hydraulic retarder is started, the transmission shaft of the hydraulic retarder drives the centrifugal impeller to rotate so as to absorb liquid. After the working liquid enters the pump cavity, the centrifugal impeller pushes the working liquid to change the movement direction and speed of the working liquid, so that the working liquid firstly accelerates and then enters the retarding cavity of the hydraulic retarder. At the moment, the centrifugal pump can effectively achieve the purpose of preventing liquid return due to the centrifugal drainage characteristic of the centrifugal pump. More importantly, in the working process, the working liquid can be continuously accelerated and changed in direction by the centrifugal impeller and then gushes out to the retarding cavity of the hydraulic retarder at a high speed along the unique communication hole. The change of velocity of flow and the change of flow direction at every turn all can effectual promotion working fluid pump go into the feed liquor velocity of flow in the hydraulic retarber, and this not only makes the hydraulic retarber also can possess higher braking moment when low speed, also can effectively shorten the braking response time of hydraulic retarber simultaneously, and the result is showing.

In summary, the invention combines the technical principle of a centrifugal pump in fluid machinery, and skillfully utilizes a centrifugal mechanism to enable the flowing liquid to have the characteristics of certain direction and flow speed, thereby effectively solving the problems of low flow speed of the working liquid and low flow speed of the liquid inlet when the traditional hydraulic retarder works. In practical use, the invention can not interfere the original structure of the original hydraulic retarder, can be directly used as an external hanging part of the original hydraulic retarder, has lower updating cost of products, and is obviously more beneficial to popularization and application of the invention.

2) And for the communicating holes, 1 to 4 or more groups may be taken as appropriate in actual use. The invention preferably uses a group of communication holes, which leads working liquid to be driven by the centrifugal impeller to circumferentially surround the pump cavity for a circle after entering the pump cavity of the invention, so as to obtain enough centrifugal acceleration and then throw the centrifugal acceleration into the speed-reducing cavity through the communication holes at the partition plate, and finally realize the purpose of maximizing the speed-increasing of the liquid inlet flow rate. The distance between the communicating hole and the axis of the transmission shaft is larger than or equal to the distance between the top edge of the impeller blade of the centrifugal impeller and the axis of the transmission shaft, so that the working liquid can smoothly and unimpededly flow through the pore channel, the pump cavity and the communicating hole in sequence, and the flow rate of the working liquid is ensured not to be subjected to additional resistance.

3) On the basis of the structure of a front end cover cylinder cavity of a cylindrical distribution cavity of the original hydraulic retarder, the end part of the front end cover cylinder cavity is designed with a smooth fillet, so that the fillet, a rotor of the hydraulic retarder and the inner side surface of a partition plate can jointly enclose to form an annular drainage cavity channel, and the smoothness of liquid inlet smoothness of working liquid can be further ensured.

4) The centrifugal impeller is fixedly connected in a manner of screwing and fixedly connecting the key connection and the cover type nut, so that the purpose of conveniently and rapidly fixing the centrifugal impeller relative to the transmission shaft in the circumferential direction and the axial direction is achieved. An oil seal ring is arranged at the gap between the partition plate and the shaft body of the transmission shaft, so that the purpose of sealing a matching gap between the transmission shaft serving as a movable part and the partition plate serving as a static part is achieved, and the independence of a flow channel between the drainage cavity channel and the pump cavity is guaranteed. As for the O-shaped ring which is arranged between the pump cover and the clapboard and is used for sealing the gap between the pump cover and the clapboard, the O-shaped ring can prevent the working liquid in the pump cavity from leaking outwards under high pressure so as to ensure the working reliability of the whole structure.

Drawings

FIG. 1 is a schematic view of an assembly structure of the present invention;

FIG. 2 is a fluid flow state diagram of a hydraulic damper incorporating the present invention;

FIG. 3 is a cross-sectional view of a centrifugal impeller;

FIG. 4 is a left side view of FIG. 3;

FIG. 5 is a cross-sectional view of a separator plate;

FIG. 6 is a left side view of FIG. 5;

FIG. 7 is a cross-sectional view of the rotor with the rotor blades removed;

FIG. 8 is a left side view of FIG. 7;

FIG. 9 is a cross-sectional view of the front end cap;

fig. 10 is a partial cross-sectional view of the end face of the barrel.

The actual correspondence between each label and the part name of the invention is as follows:

jk-working fluid inlet ck-working fluid outlet

a-front end cover b-cylinder c-rear end cover d-rotor e-transmission shaft

10-partition 11-communication hole

20-Pump Cap 21-pore channel

30-centrifugal impeller 31-wheel blade 32-liquid guide amplitude plate 33-liquid guide cone

40-fillet 50-cap nut

60-oil seal ring 70-fastening screw 80-O-shaped ring

Detailed Description

For convenience of description, the specific construction of the conventional hydraulic buffer will be described as follows:

the structure of a traditional hydrodynamic retarder is shown in a structure on the right side of fig. 1, and comprises a transmission shaft e, wherein a rotor d is sleeved on the transmission shaft e, and the transmission shaft e is matched with an automobile spindle through a clutch. The stator of the hydrodynamic retarder, namely the shell, is formed by matching a front end cover a, a cylinder b and a rear end cover c. The structure of the rotor d is shown in figures 7-8, the structure of the front end cover a is shown in figure 9, and the structure of the cylinder b is shown in figure 10. When the rotor d is matched with the stator to form a matching as shown in figures 1-2, once braking is needed, a gear is firstly engaged through the clutch, and the transmission shaft e is connected with a main shaft of the automobile. Then, the working fluid firstly enters the left inlet of the hydrodynamic retarder and gushes into the retarder cavity of the hydrodynamic retarder as shown in fig. 2 through a series of flow channels, so as to achieve the purpose of limiting the rotating speed of the rotor d through the formation of circulation. In the process that the working liquid flows in the retarding cavity, when the working liquid rotates to a position near the concave liquid collecting tank shown in fig. 10, a part of the working liquid flows out of the hydrodynamic retarder through the working liquid outlet ck shown in fig. 10, and then flows back to the liquid inlet at the left end of the hydrodynamic retarder after being cooled by the external radiator to continue working.

The specific structure and operation of the present invention will be further described with reference to the accompanying drawings, 1-6, based on the above structure:

the specific structure of the present invention is shown with reference to fig. 1-6, and the main structure thereof includes a pump cover 20, a centrifugal impeller 30 and a partition plate 10 which are sequentially arranged from left to right along the axial direction of a transmission shaft e, wherein:

the pump cover 20 is in a disc cover shape with the cover opening facing to the right side as shown in fig. 1-2, a duct 21 is coaxially and horizontally arranged at the pump cover 20 in a penetrating manner, and the left end of the duct 21 extends outwards along the axial direction to form a working liquid inlet jk with a cylindrical structure. The flange is arranged at the rim of the pump cover 20 so as to sequentially penetrate through the flange and the plate body of the partition plate 10 by fastening screws 70 and finally fasten the pump cover 20 and the partition plate 10 on the front end cover a of the hydrodynamic retarder. The O-ring 80 is disposed between the pump cover 20 and the diaphragm 10 to function as a seal for the gap therebetween. The partition plates 10 cooperate with the pump cover 20 to jointly enclose a pump chamber which is in the shape of a stepped annular cavity and can be accommodated by the centrifugal impeller 30.

For the centrifugal impeller 30, the transmission shaft e is coaxially arranged on the axis of the stepped annular cavity-shaped pump cavity, at this time, one end of the transmission shaft e extends out of the left end of the shell and serves as a transmission connecting end, and the transmission connecting end of the transmission shaft e is provided with threads so as to be in threaded fit with the cap nut 50 and a shaft shoulder at the transmission shaft e, so that the purpose of limiting the axial action of the centrifugal impeller 30 is achieved. Meanwhile, the centrifugal impeller 30 is fixedly connected with the transmission shaft e in a flat key or spline connection mode so as to limit the circumferential rotation motion of the centrifugal impeller 30 relative to the axis of the transmission shaft e. The centrifugal impeller 30 may be arranged in various manners, and when it is shown in the structure shown in fig. 1, a plurality of sets of impeller blades 31 are provided thereon, and each impeller blade 31 is fixed at the liquid guide web 32. In the structure of the centrifugal impeller 30 shown in fig. 3 to 4, each impeller blade 31 is formed of a curved thin plate having the same shape and size, and the impeller blades 31 are sequentially and uniformly distributed around the circumferential direction of the drive shaft e, eventually forming a scroll-like configuration as shown in fig. 4. Through the structure, once the centrifugal impeller 30 rotates under the driving of the transmission shaft e, the convex surfaces of the blades 31 always push the surface of the water body, and the concave surfaces of the blades 31 always form a water suction surface, so that the aims of preventing liquid return and increasing the flow rate of the inlet liquid are fulfilled. In actual manufacturing, the number of the blades 31 needs to be set according to design, the specific curvature of the blades 31 needs to be obtained according to a blade profile differential equation, and the size is determined by the liquid flow and the rotating speed of the hydraulic retarder. The liquid guide radial plate surface is vertical to the axis of the transmission shaft e, and a truncated cone-shaped liquid guide cone 33 is arranged at the axis position of the centrifugal impeller 30. The liquid guiding cone 33 is coaxially and fixedly connected with the transmission shaft e, and the conical surface of the liquid guiding cone also forms a certain angle with the axis of the transmission shaft e, so that the function of guiding the working liquid from the pore channel 21 to enter the impeller blade 31 is achieved.

As shown in fig. 5-6, the partition plate 10 is a circular-wall thin-plate structure, and is designed to provide a certain liquid-proof effect for the fluid in the pump chamber, so as to prevent the working fluid from flowing back in the drainage channel and even the retarding chamber. The partition 10 is provided with a communication hole 11 in the axial direction, and the communication hole 11 should be not lower than the top edge of the vane 31 in the assembled condition to ensure thatThe smooth outflow of the working fluid is confirmed. The size of the communication holes 11 depends on the working medium and the required liquid flow rate, and in the structure shown in FIGS. 1-2, it is preferable that the number of the communication holes 11 is one and the diameter of the holes is set to

ToIt is preferable that the number and size of the communication holes 11 are not limited to these.

The shape of the drainage cavity is shown in fig. 1-2, and is in a stepped annular cavity layout with a left thick part and a right thin part, and the drainage cavity is formed by enclosing a baffle plate 10, a fillet 40 at a front end cover a and a rotor of the hydraulic retarder together. In actual use, due to the existence of the oil seal ring 60 and the partition plate 10, the working liquid in the pump cavity and the drainage cavity channel are isolated from each other and are communicated with each other only through the communication hole 11 at the partition plate 10.

In order to better illustrate the working effect of the present invention, the practical working flow of the present invention is further described herein with reference to fig. 1-2 as follows:

when the hydraulic retarder works, the hydraulic retarder is fixed at the liquid inlet end of the hydraulic retarder, and the shell of the hydraulic retarder, namely the stator, is fixed on a vehicle body. The transmission shaft e is in transmission connection with a vehicle main shaft; and completely emptying the working liquid in the hydraulic retarder in the initial state.

As shown in fig. 1-2, when the vehicle needs to be braked at a slow speed, firstly, the pressure valve is matched with the pressure pump in action, and the working fluid passively passes through the pump cavity, the communication hole 11 and the drainage cavity channel in sequence from the working fluid inlet jk, namely the left port of the pore channel 21 of the pump cover 20, and finally enters the slow speed cavity of the hydrodynamic retarder and is filled with the slow speed cavity of the hydrodynamic retarder quickly. The transmission shaft e in transmission connection with the vehicle main shaft drives the centrifugal impeller 30 in the pump cavity to synchronously rotate under the driving of the rotating force of the vehicle main shaft, so that negative pressure is formed in the pump cavity and working liquid is actively sucked in through the working liquid inlet jk. After the working fluid enters the pump cavity, the working fluid is pushed by the wheel blades 31 of the centrifugal impeller 30 to change the moving direction and speed of the working fluid. The working fluid is not only rotated at high speed by the centrifugal impeller 30, but also thrown out at high speed along the blades 31 of the centrifugal impeller 30 to the edges of the blades 31 by the centrifugal force. The working fluid is blocked and guided by the pump cover 20, and flows to the vicinity of the communication hole 11 of the partition plate 10 in a changed direction, flows out of the pump cavity to the drainage cavity channel through the communication hole 11, and then sequentially flows into the retarder cavities of the hydrodynamic retarder through the drainage cavity channel to form a fluid flow layout as shown in fig. 2.

In the working process, the working liquid is continuously accelerated and changed in direction by the centrifugal impeller 30 and then gushes out to the retarding cavity of the hydrodynamic retarder at a high speed along the only communication hole 11. The change of velocity of flow and the change of flow direction at every turn all can promote the feed liquor velocity of flow in the hydraulic retarber of working fluid pump income, and this not only makes the hydraulic retarber also can possess higher braking moment when low speed, also makes the braking response time of hydraulic retarber sharply shorten simultaneously. In addition, the centrifugal liquid throwing action of the centrifugal impeller 30 also prevents the liquid returning condition from happening, thereby achieving multiple purposes.

When the working fluid enters the retarding cavity of the hydrodynamic retarder under the combined action of the pre-pressure of the pressure pump and the retarding force of the centrifugal impeller 30, the pressed working fluid is driven by the rotor of the hydrodynamic retarder, so that the working fluid flows between each rotor blade and each stator blade at a high speed. Through the interaction of the rotor blades at the rotor and the stator blades at the stator on flowing liquid, the flowing speed and the flowing direction of the liquid are changed rapidly, so that braking torque is generated on the rotor blades, most energy input by the transmission shaft e is consumed, energy is consumed by forming vortex between the rotor and the stator, and the comprehensive effect of the flowing state forms a slow braking effect on a vehicle. Working liquid flows at a high speed in the retarding cavity, and is finally discharged from the working liquid outlet ck under the action of centrifugal force generated by rotation of the rotor, and simultaneously, the working liquid is continuously sucked from the working liquid inlet jk, namely the left port of the pore channel 21, by the vacuum degree generated after the working liquid is discharged from the retarding cavity, and finally, the working liquid forms benign liquid flow circulation liquid along the pore channel 21, the pump cavity, the communication hole 11, the drainage cavity channel and the retarding cavity. In the process that the working liquid flows in the hydraulic retarder, the mechanical energy input by the transmission shaft e can be converted into heat energy, and the working liquid after temperature rise flows out from a working liquid outlet ck on the hydraulic retarder shell through a pipeline. The effluent working liquid is cooled by an external fluid heat exchanger, and heat is dissipated to the air by cooling liquid in the external fluid heat exchanger; the cooled working liquid enters the hydraulic retarder again through the working liquid inlet, and the hydraulic retarder is ensured to work normally through the reciprocating circulation.

Claims (6)

1. The utility model provides a centrifugal acceleration rate feed liquor system for hydraulic retarder which characterized in that: the system comprises a partition plate (10) coaxially and fixedly connected at the liquid inlet end of a front end cover of the hydrodynamic retarder, wherein one side surface of the partition plate (10) facing the front end cover is an inner side surface, a pump cover (20) covers the outer side surface of the partition plate (10), so that a cavity formed by enclosing the pump cover (20) and the partition plate (10) forms a pump cavity for arranging a centrifugal impeller (30), and a transmission shaft of the hydrodynamic retarder coaxially penetrates through the partition plate (10) and then forms a fixedly connected fit relation with the centrifugal impeller (30); a pore passage (21) axially penetrates through the pump cover (20) to form a liquid inlet flow passage communicated with the inlet end of the centrifugal impeller (30) in the pump cavity; the axial direction of the partition plate (10) is provided with a communicating hole (11) in a penetrating way, so that the outlet end of the centrifugal impeller (30) in the pump cavity is communicated with the retarding cavity of the hydrodynamic retarder.

2. The centrifugal speed-increasing liquid inlet system for the hydraulic retarder according to claim 1, is characterized in that: the communication holes (11) are round holes, and the communication holes (11) form a group; the distance between the communication hole (11) and the axis of the transmission shaft is larger than or equal to the distance between the top edge of the blade of the centrifugal impeller (30) and the axis of the transmission shaft.

3. The centrifugal speed-increasing liquid inlet system for the hydraulic retarder according to claim 2, is characterized in that: fillet (40) are arranged at the liquid inlet end cavity of front end cover to enclose jointly with the rotor of hydraulic retarber and baffle (10) medial surface and close the drainage cavity way that forms drainage smoothly, the drainage cavity way appearance is the annular chamber form coaxial with the transmission shaft, the one end that the drainage cavity said links to each other with intercommunicating pore (11) and the slow speed chamber of other end intercommunication hydraulic retarber.

4. A centrifugal speed-increasing liquid inlet system for a hydraulic retarder according to claim 1, 2 or 3, characterized in that: the circumferential movement of the centrifugal impeller (30) relative to the drive shaft is restricted by a key connection, and the axial movement of the centrifugal impeller (30) relative to the drive shaft is restricted by clamping the centrifugal impeller (30) by the cooperation of the cap nut (50) and the shoulder.

5. A centrifugal speed-increasing liquid inlet system for a hydraulic retarder according to claim 1, 2 or 3, characterized in that: an oil seal ring (60) is arranged at the gap between the clapboard (10) and the shaft body of the transmission shaft.

6. A centrifugal speed-increasing liquid inlet system for a hydraulic retarder according to claim 1, 2 or 3, characterized in that: the fastening screw (70) sequentially and axially penetrates through the pump cover (20) and the partition plate (10) and is fixedly connected to the end face of the liquid inlet end of the front end cover in a threaded mode, and an O-shaped ring (80) used for sealing a gap between the pump cover (20) and the partition plate (10) is arranged between the pump cover (20) and the partition plate.

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