CN114011041A

CN114011041A - Tennis serving device

Info

Publication number: CN114011041A
Application number: CN202111437959.8A
Authority: CN
Inventors: 李康; 李健; 许强
Original assignee: Ningbo University
Current assignee: Ningbo University
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2022-02-08
Anticipated expiration: 2041-11-30
Also published as: CN114011041B

Abstract

The invention discloses a tennis serving device, which relates to the technical field of tennis equipment and adopts the technical scheme that: the device comprises a rack, a first pressing wheel mechanism, a second pressing wheel mechanism and a ball feeding track, wherein the first pressing wheel mechanism, the second pressing wheel mechanism and the ball feeding track are arranged on the rack; the ball delivery track is used for delivering the tennis ball into the ball delivery gap; the first pressing wheel mechanism comprises a first rotating shaft, a first pressing wheel and a first driving device, and the first pressing wheel is installed through the first rotating shaft and is driven to rotate through the first driving device; the second pressing wheel mechanism comprises a second rotating shaft, a first half wheel, a second half wheel and a second driving device, wherein the first half wheel and the second half wheel are coaxially arranged through the second rotating shaft and are driven to rotate through the second driving device; a spherical shaft sleeve is arranged between the first half wheel and the second rotating shaft, the periphery of the spherical shaft sleeve and the inner periphery of the first half wheel are spherical surfaces which are matched with each other, and a ball head on the inner periphery of the first half wheel is connected to the periphery of the spherical shaft sleeve. The tennis serving device can adjust the rotating direction of the serving tennis, and the application range of the tennis serving device is widened.

Description

Tennis serving device

Technical Field

The invention relates to the technical field of tennis equipment, in particular to a tennis serving device.

Background

In the process of tennis, tennis lovers often carry out tennis training, or double-person pair-play training, or adopt tennis serving equipment to train; because the double persons are limited by the persons for playing, the service robot training which can be carried out by a single person is welcomed by tennis lovers.

The Chinese invention patent with the publication number of CN110124293A discloses a tennis ball serving machine, which adopts the technical scheme that: the device comprises a base, an annular slide block, a first sleeve, a slide rod, a first spring, a transmitting tube, a rack, a second spring, a discharging tube, a discharging hopper, a handle, a push block and the like; open in the middle of the base top has annular spout, and annular spout internal sliding formula is equipped with annular slider, and annular slider and annular spout sliding fit, the first sleeve that plays the guide effect is two.

The existing tennis ball launching equipment can only throw tennis balls, the tennis ball launching process is single, and the tennis ball launching equipment can only be simply adjusted in position or power, so that the direction and the parabola height of launched tennis balls are changed, the tennis ball launching equipment can only meet simple training requirements, and the use requirements of sports enthusiasts or professional athletes cannot be met.

Therefore, a new solution is needed to solve this problem.

Disclosure of Invention

The present invention has been made to solve the above problems, and an object of the present invention is to provide a tennis serving device capable of adjusting the direction of rotation of a serving ball and increasing the range of applicability of a tennis serving apparatus.

The technical purpose of the invention is realized by the following technical scheme: a tennis serving device comprises a rack, a first pressing wheel mechanism, a second pressing wheel mechanism and a ball feeding track, wherein the first pressing wheel mechanism, the second pressing wheel mechanism and the ball feeding track are arranged on the rack; the first pressing wheel mechanism and the second pressing wheel mechanism are driven to rotate by the first driving device and the second driving device respectively and are used for launching tennis balls; the ball feeding track is used for feeding the tennis ball into the ball serving gap; the first pressing wheel mechanism comprises a first rotating shaft, a first pressing wheel and a first driving device, and the first pressing wheel is installed through the first rotating shaft and is driven to rotate through the first driving device; the second pressing wheel mechanism comprises a second rotating shaft, a first half wheel, a second half wheel and a second driving device, wherein the first half wheel and the second half wheel are coaxially arranged through the second rotating shaft and are driven to rotate through the second driving device; a spherical shaft sleeve is arranged between the first half wheel and the second rotating shaft, the inner periphery of the spherical shaft sleeve is axially and limitedly connected outside the rotating shaft in a rotating mode, the outer periphery of the spherical shaft sleeve and the inner periphery of the first half wheel are spherical surfaces matched with each other, and a ball head on the inner periphery of the first half wheel is connected to the outer periphery of the spherical shaft sleeve.

The rotating shaft II comprises a first half shaft and a second half shaft which are coaxially arranged, one end of the first half shaft, which is opposite to the second half shaft, is rotatably supported through a first rotating bearing, a connecting sleeve is arranged at one end of the first half shaft, which faces the second half shaft, and the second half shaft extends into the connecting sleeve of the first half shaft; the first half shaft is connected with the second driving device, the first half shaft is fixedly connected with a driving disc, and the driving disc is connected and driven with the outer side of the first half wheel through a plurality of driving belts distributed in an annular array.

The invention is further provided that the end surface of the driving disc facing the first half wheel is fixedly connected with a plurality of first springs distributed in an annular shape, and the first springs elastically press against the end surface of the outer side of the first half wheel.

The invention is further provided that one side of the driving disc, which is opposite to the first half wheel, is provided with a first adjusting ring, the first adjusting ring is connected outside the first half wheel in a threaded manner, one end of the driving belt is fixedly connected to the end surface of the outer side of the first half wheel, and the other end of the driving belt penetrates through the through hole in the driving disc and is fixedly connected with the periphery of the first adjusting ring.

The invention is further arranged in that a second adjusting ring is arranged between the first driving disc and the first adjusting ring, the second adjusting ring is rotatably sleeved on the step bulge of the second half shaft and is pressed and locked with the driving disc through the first adjusting ring; and a second through hole corresponding to the first through hole is formed in the second adjusting ring.

The invention is further provided that the half wheel II can be sleeved on the periphery of the half shaft II to keep synchronous rotation and can axially slide relative to the half shaft II; one side of the half wheel II, which faces the half shaft, is provided with a first stepped hole for the connecting sleeve to extend into, and the end surface of the connecting sleeve is abutted against the bottom surface of the first stepped hole, so that axial rotation transmission is realized; one side of the half wheel II, which is back to the half shaft, is elastically pressed by the spring II, and the end surface of the connecting sleeve is pressed against the bottom surface of the stepped hole I.

The invention is further provided that a second key groove used for accommodating the connecting key is formed in the periphery of the second half shaft, and a first key groove matched with the connecting key in a sliding mode is formed in a shaft hole of the second half shaft.

The invention is further arranged in such a way that the end surface of the connecting sleeve and the bottom surface of the stepped hole are inclined surfaces which are matched with each other, and the end surface of the connecting sleeve and the bottom surface of the stepped hole are pressed against each other through the inclined surfaces for transmission.

The end face of the connecting sleeve and the bottom face of the stepped hole are provided with end face ratchets which are matched with each other, and the end face of the connecting sleeve and the bottom face of the stepped hole are mutually pressed and driven through the end face ratchets.

The invention is further arranged in that one end of the half wheel II, which is far away from the half wheel I, is fixedly connected with a support sleeve, the support sleeve is sleeved on the outer periphery of the half shaft II, a convex ring is formed on the end surface of the support sleeve, one side of the support sleeve, which is far away from the half wheel II, is provided with a driving wheel II, and the inner periphery of the driving wheel II is rotationally connected to the half shaft II through a rotary bearing II; one side of the driving wheel II facing the support sleeve is provided with a first stepped hole, the inner periphery of the first stepped hole is fixedly connected with a baffle ring, and a spring II is elastically abutted between the baffle ring and the convex ring.

The invention is further provided that the periphery of the support sleeve is fixedly connected with a transmission sleeve, and the transmission sleeve is used for moving towards two sides of the transmission wheel and realizing the friction transmission of the transmission sleeve and the transmission wheel II; the driving wheel II is connected with the driving wheel I on the rotating shaft I through a belt, so that the driving of the driving wheel I and the driving wheel II is realized; the belt is tensioned through a tensioning wheel.

The invention is further provided that a thrust bearing is arranged between the second spring and the baffle ring, and the thrust bearing comprises a seat ring, a shaft ring, a rolling body between the seat ring and the shaft ring.

The invention is further provided that one end of the transmission sleeve opposite to the transmission wheel II is respectively provided with a conical friction surface I and a conical friction surface II which are matched with each other, and the conical friction surface I and the conical friction surface II are used for mutually abutting and friction transmission.

The invention is further arranged in such a way that the transmission sleeve can axially slide on the periphery of the support sleeve and is locked by the locking bolt, and the sections of the transmission sleeve and the support hole are hexagonal, so that axial rotation and fixation can be realized.

The invention is further provided that an expansion mechanism is arranged at the lower position between the first half wheel and the second half wheel, the expansion mechanism comprises an arc-shaped expansion frame and two expansion half wheels arranged between the expansion frames, an expansion shaft capable of being axially adjusted is arranged between the expansion frames, and the expansion shaft is adjusted through a second expansion rod; the two expansion half wheels are respectively and rotatably connected to the expansion shaft and are used for respectively abutting against the peripheries of the half wheel I and the half wheel II.

The expansion mechanism further comprises a third expansion rod, wherein the third expansion rod is arranged on the rack and used for adjusting the position of the expansion frame relative to the second pressing wheel mechanism; the expansion frame is arranged at the telescopic end of the telescopic rod III.

In conclusion, the invention has the following beneficial effects:

the first half wheel and the second half wheel are independent structures in the second pinch roller mechanism, and the first half wheel is movably arranged; after the tennis ball enters the serving gap, the first half wheel is squeezed to swing and expand towards one side, so that certain outward swing is formed in the launching process of the tennis ball, the tennis ball is laterally rotated, and the tennis serving device has a wide application range.

By driving the half wheel I by a flexible driving belt, the transmission between the half wheel I and the driving wheel I can be still maintained during the process that the half wheel I launches a certain lateral swing, and flexible transmission is formed. The flexible transmission mode can be used for the half wheel I to generate lateral deflection, and the stability in the ball serving process is kept.

The first adjusting ring and the second adjusting ring are connected with each other, so that the working degree of the flexible driving belt can be adjusted, and the movement change condition of the first half wheel in the ball serving process can be adjusted; the tennis ball has richer serving states by adjusting the lateral rotation amplitude of the adjustable tennis ball.

Drawings

FIG. 1 is a schematic structural view of a tennis ball serving device according to the present invention;

FIG. 2 is a schematic structural diagram of a first pinch roller mechanism and a second pinch roller mechanism of the present invention;

FIG. 3 is a schematic structural view of a half wheel I, a half shaft I and a driving disk of the present invention;

FIG. 4 is a schematic view of the construction of the connection between the first half shaft and the second half shaft of the present invention;

FIG. 5 is a schematic structural diagram of a second driving wheel and a second supporting sleeve on a second half wheel of the present invention;

FIG. 6 is a schematic structural diagram of a first driving wheel, a second driving wheel and a tensioning wheel according to the present invention;

fig. 7 is a schematic structural diagram of a first pinch roller mechanism, a second pinch roller mechanism and an expansion mechanism of the invention.

Reference numerals: 1. a frame; 2. a first pressing wheel mechanism; 21. a first pressing wheel; 22. a first rotating shaft; 23. a serving gap; 3. a first driving device; 4. a second pinch roller mechanism; 40. a second rotating shaft; 41. half a round one; 411. a spherical surface; 42. a second half wheel; 421. a first stepped hole; 422. a bevel; 423. a first key groove; 43. a first half shaft; 431. connecting sleeves; 44. a first rotating bearing; 45. a half shaft II; 451. a second key groove; 452. a connecting bond; 46. a spherical shaft sleeve; 47. a drive disc; 471. a drive belt; 472. a first spring; 473. a first through hole; 474. adjusting a ring I; 475. a step protrusion; 476. adjusting a ring II; 477. a second through hole; 48. a support sleeve; 481. a convex ring; 49. a transmission sleeve; 491. a conical friction surface I; 492. locking the screw hole; 493. locking the bolt; 5. a second driving device; 6. a ball delivery track; 71. a first transmission wheel; 72. a second driving wheel; 73. a belt; 74. a tension wheel; 75. a first telescopic rod; 721. a second stepped hole; 722. a baffle ring; 723. a thrust bearing; 724. a seat ring; 725. a collar; 726. a second spring; 727. a second rotating bearing; 728. a conical friction surface II; 8. an expansion mechanism; 81. an expansion frame; 82. expanding the half wheel; 83. an expansion shaft; 84. a sliding sleeve; 85. a second telescopic rod; 86. and a third telescopic rod.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

The embodiment discloses a tennis serving device, as shown in fig. 1, which comprises a frame 1, and a first pressing wheel mechanism 2, a second pressing wheel mechanism 4 and a ball delivery track 6 which are arranged on the frame 1; the first pinch roller mechanism 2 and the second pinch roller mechanism 4 are driven to rotate by a first driving device 3 and a second driving device 5 respectively; the first pressing wheel mechanism 2 and the second pressing wheel mechanism 4 can rotate in opposite directions, a service gap 23 capable of containing tennis balls is formed between the first pressing wheel mechanism and the second pressing wheel mechanism, and the tennis balls are launched in a matching mode after entering the gap; the ball feeding track 6 is inclined, and the lower end position thereof is connected to the ball serving gap 23 between the first pressing wheel mechanism 2 and the second pressing wheel mechanism 4, so that the tennis ball can be fed into the ball serving gap 23 and then launched.

As shown in fig. 2, the first pinch roller mechanism 2 and the second pinch roller mechanism 4 are arranged in an up-down structure, and the first pinch roller mechanism 2 is positioned on the upper side of the second pinch roller mechanism 4; the pinch roller mechanism I2 comprises a rotating shaft I22, a pinch roller I21 and a driving device I3, wherein the pinch roller I21 is installed through the rotating shaft I22 and is driven to rotate through the driving device I3; the first driving device 3 can be connected with the first rotating shaft 22 in a belt 73 transmission or speed reducer transmission mode to realize transmission.

The second pinch roller mechanism 4 comprises a second rotating shaft 40, a first half wheel 41, a second half wheel 42 and a second driving device 5, wherein the first half wheel 41 and the second half wheel 42 are coaxially arranged through the second rotating shaft 40 and are driven to rotate through the second driving device 5; the driving device II 5 can also be driven by adopting a belt 73 transmission mode, a speed reducer mode and the like; the peripheries of the half wheel I41, the half wheel II 42 and the upper side pinch wheel I21 are sunken to form a ball serving gap 23.

As shown in fig. 2 and 3, the first half wheel 41 is connected with the second rotating shaft 40 through a spherical shaft sleeve 46, wherein the inner periphery of the spherical shaft sleeve 46 is axially and limitedly connected to the outside of the second rotating shaft 40 in a rotating manner, and the spherical shaft sleeve 46 can only rotate on the outer periphery of the second rotating shaft 40; the outer periphery of the spherical shaft sleeve 46 is a spherical surface 411, the inner periphery of the half wheel 41 is also provided with concave spherical surfaces 411 which are matched with each other, the spherical surfaces 411 and the half wheel 41 are assembled with each other to form a ball head connection structure, and the half wheel 41 can rotate and swing on the outer side of the spherical shaft sleeve 46; after the tennis ball enters the ball serving gap 23, the half wheel 41 is squeezed to swing and expand to one side, so that certain outward swinging is formed during the launching process of the tennis ball, and the tennis ball is laterally rotated.

The second rotating shaft 40 comprises a first half shaft 43 and a second half shaft 45 which are coaxially mounted, and one end of the first half shaft 43, which is opposite to the second half shaft 45, is rotatably supported through a first rotating bearing 44; one end of the first half shaft 43, which faces the second half shaft 45, is coaxially connected with a connecting sleeve 431, the second half shaft 45 partially extends into the connecting sleeve 431 of the first half shaft 43 and is connected with the opposite end, so that relative rotation can be performed, and a certain degree of bearing is realized to keep the stability of the rotation process;

the first half shaft 43 in the second rotating shaft 40 is connected with the second driving device 5, the first half shaft 43 is driven by the second driving device 5 to rotate, the first half shaft 43 is fixedly connected with a driving disc 47, a plurality of driving belts 471 are connected between the driving disc 47 and the outer end face of the first half wheel 41, the driving belts 471 are distributed in an annular array, and the first half wheel 41 is driven to rotate when the driving disc 47 rotates along with the first half shaft 43; due to the connection of the flexible driving belt 471, the transmission between the half wheel 41 and the driving belt can be maintained during the launching of a certain lateral swing of the half wheel 41, so that the flexible transmission is formed. The flexible transmission mode can generate lateral deflection for the half wheel 41, thereby providing technical conditions for lateral rotation of tennis balls.

The half wheel II 42 is arranged on the half shaft II 45, and the half shaft II 45 is not driven by power and only keeps driven rotation; and the half wheels are mutually transmitted with the half shafts 43 through the connecting structure.

In order to keep the amplitude of the deflection process of the first half wheel 41 and maintain certain stability, the first spring 472 can be pressed between the first half wheel 41 and the driving disc 47, which are faced by the driving disc 47, so that the first half wheel 41 has certain automatic recovery effect; the number of the first springs 472 is four to eight, and the first springs are stably supported at each circumferential position in an annular array structure; one end of the first spring 472 is specifically connected to the end face of the driving disc 47, and the other end of the first spring is abutted against the outer end face of the first half wheel 41, so that elastic support is formed. The first spring 472 can adopt a common spring, and can also adopt structures such as an inflatable air bag with adjustable elasticity or an air spring and the like to adjust the elastic supporting force of the first spring 472 so as to adapt to more adjusting conditions.

Since the driving disc 47 and the first half wheel 41 are driven by the flexible driving belt 471, after tennis balls enter the position before the first half wheel 41 and the second half wheel 42, the first half wheel 41 will receive a certain frictional resistance, a certain rotation resistance will be generated between the first half wheel 41 and the driving disc 47, and the second half wheel 42 side will continue to rotate synchronously with the rotating shaft, so that a certain rotation speed difference will be generated between the first half wheel 41 and the second half wheel 42 at the moment of serving tennis, a certain lateral rotation is formed, and the speed is faster at the second half wheel 42 side.

In order to adjust the difference in rotational speed between the drive disc 47 and the half-wheel 41, the drive belt 471 can be provided in a slightly adjustable configuration; specifically, an adjusting ring one 474 can be arranged on the side of the driving disc 47, which is opposite to the half wheel one 41, and the inner circumference of the adjusting ring one 474 is in threaded connection with threads on the outer side of the half shaft one 43; one end of each driving belt 471 is fixedly connected to the outer end face of the half wheel I41, and the other end of each driving belt 471 passes through the through hole I473 in the driving disc 47 and is fixedly connected with the outer periphery of the adjusting ring I474, so that the driving belts 471 are installed;

a second adjusting ring 476 can be continuously installed between the driving disc 47 and the first adjusting ring 474, and the second adjusting ring 476 is rotatably sleeved on the stepped protrusion 475 of the second half shaft 45 to form a rotating adjusting structure; a second through hole 477 corresponding to the driving belt 471 in a one-to-one manner is formed in the adjusting ring II 476, and the driving belt 471 passes through the second through hole 477; during the adjustment process, the position of the second adjusting ring 476 can be adjusted in a rotating way, so that the length of the driving belt 471 extending between the driving disc 47 and the first half wheel 41 is increased or decreased, after the adjustment is completed, the first adjusting ring 474 is rotated through threads, and the second adjusting ring 476 is pressed and locked between the first adjusting ring 474 and the driving disc 47 to be kept fixed;

in the adjusting process, the length of the driving belt 471 extended between the driving disc 47 and the half wheel I41 is increased, so that the rotation deviation of the driving disc 47 and the half wheel I41 can be increased, the deceleration of the half wheel I41 at the ball serving moment can be increased, the deviation of the speeds at two sides in the ball serving process is increased, and the amplitude of the lateral rotation is increased; and reducing the length of the drive belt 471 extending between the drive disc 47 and the half wheel 41 correspondingly reduces the lateral rotation amplitude of the serve, thereby enabling the amplitude of the serve to be adjusted.

Example two

The present embodiment discloses a tennis ball serving device, which is described with reference to fig. 4-6 on the basis of the first embodiment; the embodiment describes the mounting structure of the second half wheel 42 in detail, and the adjustable structure is adopted between the second half wheel 42 and the first half shaft 43 and the second half shaft 45 for connection transmission.

The half wheel II 42 is sleeved on the periphery of the half shaft II 45, the synchronous rotation of the half wheel II 42 and the half shaft II 45 is kept through a rotary limiting structure, and the half wheel II 42 can axially slide on the half shaft II 45 in a certain range; specifically, the connection can be performed by adopting a sliding key structure, a second key groove 451 for accommodating the connection key 452 is formed in the outer periphery of the second half shaft 45, a first key groove 423 which is matched with the connection key 452 in a sliding manner is arranged in the shaft hole of the second half wheel 42, and the structure capable of sliding in the axial direction is formed after assembly.

A first stepped hole 421 is formed in the side, facing the first half shaft 43, of the second half wheel 42, the first stepped hole 421 can be used for a connecting sleeve 431 at the end part of the first half shaft 43 to extend into, the end surface of the connecting sleeve 431 is abutted against the stepped surface of the first stepped hole 421, and the two are connected through a connecting structure to realize axial rotation transmission; and a second spring 726 is arranged on the side of the second half wheel 42 opposite to the first half shaft 43, and under the elastic action of the second spring 726, the second half wheel 42 can be pushed towards the first half shaft 43, so that the end surface of the connecting sleeve 431 and the step surface of the step hole one 421 are stably pressed against each other, and the stable transmission between the connecting sleeve 431 and the second half wheel 42 can be maintained.

The end face of the connecting sleeve 431 and the bottom face of the stepped hole can be connected by adopting various connecting structures, for example, a structure which can realize friction transmission by parallel pressing can be directly adopted between the end face of the connecting sleeve 431 and the bottom face of the stepped hole; or the end surface of the connecting sleeve 431 and the bottom surface of the stepped hole are processed to form mutually matched inclined surfaces 422, and after the positions of the two inclined surfaces 422 are mutually pressed, certain torque transmission can be kept, so that the synchronous transmission device has better synchronism and stability compared with simple friction transmission; or end face ratchets which are mutually matched are processed and formed between the end face of the connecting sleeve 431 and the bottom face of the stepped hole, only unidirectional transmission can be realized through the matching of the end face ratchets, and different transmission states can be realized according to the elastic action of the second spring 726 in the reverse transmission process.

After the tennis ball is squeezed into the serving gap 23, a certain outward expansion effect is formed on the first half wheel 41 and the second half wheel 42, and the second half wheel 42 can be pushed to move axially to a certain degree; therefore, the connecting structure between the end face of the connecting sleeve 431 and the bottom face of the stepped hole can be separated, the speed of the half wheel I41 is reduced, the half wheel I41 can be mainly driven to rotate, and a certain lateral rotating effect can be formed.

A support sleeve 48 is fixedly connected to one end of the second half wheel 42, which is far away from the first half wheel 41, the support sleeve 48 is sleeved on the periphery of the second half shaft 45, and a convex ring 481 is formed on the end surface of the support sleeve 48; a second transmission wheel 72 is arranged on one side of the support sleeve 48 far away from the second half wheel 42, and the inner periphery of the second transmission wheel 72 is rotationally connected to the second half shaft 45 through a second rotary bearing 727; a first stepped hole 421 is formed on one side of the second transmission wheel 72 facing the support sleeve 48, a stop ring 722 protruding inwards is formed on the inner circumference of the first stepped hole 421, and the second spring 726 can be pressed between the stop ring 722 and the convex ring 481, so that the stability of the second spring 726 can be maintained; the second spring 726 can adopt a common spring, or can adopt an inflatable air bag or a gas spring with adjustable elasticity, and the like, and the size of the elastic supporting force of the second spring 726 is adjusted to adapt to more adjusting conditions, so that the size of the axial displacement of the second half wheel 42 in the process of squeezing tennis balls into the serving gap 23 is adjusted, and the connecting state between the second half wheel 42 and the connecting sleeve 431 is adjusted.

In order to maintain the installation stability of the spring II 726, a thrust bearing 723 can be arranged between the spring II 726 and the retainer ring 722, and the thrust bearing 723 comprises a seat ring 724, a collar 725, rolling bodies between the seat ring 724 and the collar 725, so that the condition of abrasion generated on the end face of the spring II 726 is avoided.

A driving sleeve 49 is fixedly connected to the periphery of the supporting sleeve 48, the driving sleeve 49 can move towards the second driving wheel 72 synchronously with the second half wheel 42, and friction transmission between the driving sleeve 49 and the second driving wheel 72 is realized, so that the second half wheel can be driven through the second driving wheel 72.

The second transmission wheel 72 can be connected with the first transmission wheel 71 on the first rotating shaft 22 through a belt 73, so that the transmission of the first transmission wheel 71 and the second transmission wheel 72 is realized, the second half wheel 42 can be driven through the first transmission device, the rotation speed difference between the second half wheel 42 and the first half wheel 41 is adjusted, and the lateral rotation condition in the tennis serving process is adjusted; the belt 73 is tensioned by a tension pulley 74, and the position of the tension pulley 74 can be adjusted by a telescopic rod 75, so that the tension of the belt 73 is maintained.

The opposite ends of the transmission sleeve 49 and the second transmission wheel 72 can be processed to form a conical friction surface 491 and a conical friction surface 728 which are mutually matched, the conical friction surface 491 and the conical friction surface 728 have good friction stability, and friction transmission can be realized after mutual abutting, so that switching between different power sources of the second half wheel 42 is realized.

The transmission sleeve 49 can be set into an adjustable structure, the transmission sleeve 49 can axially slide on the periphery of the support sleeve 48, and the sections of the transmission sleeve 49 and the support hole are hexagonal, so that axial rotation and fixation can be realized; a locking screw hole 492 is formed in the transmission sleeve 49, and the locking screw 493 is screwed into the locking screw hole 492 and is pressed against the end surface of the support sleeve 48 through the end surface of the locking screw 493, so that locking is realized; therefore, the friction pressing condition between the transmission sleeve 49 and the second driving wheel 72 can be adjusted, the adjustment can be carried out according to the abrasion condition generated in the using process, and the smooth friction transmission between the transmission sleeve 49 and the second driving wheel 72 can be always kept.

EXAMPLE III

The embodiment discloses a tennis serving device, which is described with reference to fig. 7 on the basis of the first embodiment and the second embodiment; in the embodiment, the expansion mechanism 8 is added, and the relative position between the first half wheel 41 and the second half wheel 42 can be adjusted and limited through the expansion mechanism 8, so that the elastic movement state of the first half wheel 41 and the second half wheel 42 after the tennis ball is squeezed into the serving gap 23 can be adjusted.

Specifically, the expanding mechanism 8 is arranged at a position lower between the first half wheel 41 and the second half wheel 42, the expanding mechanism comprises an arc-shaped expanding frame 81 and two expanding half wheels 82, the two expanding half wheels 82 are arranged between the arc-shaped expanding frames 81 through an expanding shaft 83, and the shape of the two half wheels is close to the outline of the tennis ball.

An expansion shaft 83 between the expansion frames 81 is parallel to the second rotating shaft 40, the expansion shaft 83 can axially slide in a certain range under the support of sliding sleeves 84 on two sides of the expansion frames 81, a second expansion rod 85 is installed on one side of the expansion frames 81, and the position of the expansion shaft 83 is adjusted through the second expansion rod 85. The expansion mechanism 8 further comprises a third telescopic rod 86, the third telescopic rod 86 is installed on the rack 1, the expansion frame 81 is installed at the telescopic end of the third telescopic rod 86, and the position of the expansion frame 81 relative to the second pressing wheel mechanism 4 can be adjusted through the third telescopic rod 86.

The two expansion half wheels 82 are respectively rotatably connected to the expansion shaft 83 and can respectively abut against the peripheries of the first half wheel 41 and the second half wheel 42, the positions of the two expansion half wheels 82 can be adjusted by adjusting the second expansion rod 85, the two expansion half wheels can abut against the first half wheel 41 and the second half wheel 42, and the action of pushing the first half wheel 41 and the second half wheel 42 can be adjusted outwards. For example, when the half wheel 41 is pressed outward against the half wheel one 41, the opening between the half wheel one 41 and the half wheel two 42 is smaller, the half wheel one 41 cannot swing and expand outward, the initial lateral extrusion of the tennis ball is increased, the elastic deformation of the tennis ball is larger during serving, and the tennis ball mainly pushes the half wheel two 42 to move; the tennis ball will press the second half wheel 42 by the proper elasticity of the second spring 726, and the second half wheel 42 will be pushed towards the second driving wheel 72, and the second half wheel 42 will be driven by the tennis belt 73, etc., thereby forming a lateral rotary launch.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims

1. A tennis serving device comprises a rack (1), and a first pressing wheel mechanism (2), a second pressing wheel mechanism (4) and a ball feeding track (6) which are arranged on the rack (1); the pressing wheel mechanism I (2) and the pressing wheel mechanism II (4) are driven to rotate by the driving device I (3) and the driving device II (5) respectively and are used for launching tennis balls; the device is characterized in that the first pinch roller mechanism (2) comprises a first rotating shaft (22), a first pinch roller (21) and a first driving device (3), wherein the first pinch roller (21) is installed through the first rotating shaft (22) and is driven to rotate through the first driving device (3); the second pinch roller mechanism (4) comprises a second rotating shaft (40), a first half wheel (41), a second half wheel (42) and a second driving device (5), wherein the first half wheel (41) and the second half wheel (42) are coaxially arranged through the second rotating shaft (40) and are driven to rotate through the second driving device (5); set up spherical axle sleeve (46) between half wheel (41) and pivot two (40), the axial of interior circumference of spherical axle sleeve (46) rotates limitedly and connects outside pivot two (40), and the interior circumference of spherical axle sleeve (46) periphery and half wheel (41) is spherical face (411) of mutual adaptation, the periphery bulb is connected in the periphery of spherical axle sleeve (46) in half wheel (41).

2. A tennis ball serving device according to claim 1, wherein said second rotary shaft (40) comprises a first half shaft (43) and a second half shaft (45) which are coaxially arranged, the opposite ends of said first half shaft (43) and said second half shaft (45) are rotatably supported by a first rotary bearing (44), the end of said first half shaft (43) facing said second half shaft (45) is provided with a connecting sleeve (431), and said second half shaft (45) extends into the connecting sleeve (431) of said first half shaft (43); the first half shaft (43) is connected with the second driving device (5), the first half shaft (43) is fixedly connected with a driving disc (47), and the driving disc (47) and the outer side of the first half wheel (41) are connected and driven through a plurality of driving belts (471) distributed in an annular array.

3. A tennis ball serving device as defined in claim 2, wherein a plurality of annularly distributed springs (472) are fixedly connected to the end surface of the driving disc (47) facing the half wheel (41), and the springs (472) elastically press against the outer end surface of the half wheel (41).

4. A tennis ball serving device as defined in claim 2, wherein the side of the driving disc (47) facing away from the first half wheel (41) is provided with a first adjusting ring (474), the first adjusting ring (474) is screwed outside the first half wheel (43), one end of the driving disc (471) is fixedly connected to the outer end surface of the first half wheel (41), and the other end of the driving disc passes through the first through hole (473) of the driving disc (47) and is fixedly connected with the outer periphery of the first adjusting ring (474).

5. The tennis ball serving device as claimed in claim 4, wherein an adjusting ring II (476) is provided between the driving disc (47) and the adjusting ring I (474), the adjusting ring II (476) is rotatably sleeved on the stepped protrusion (475) of the half shaft II (45) and is pressed and locked with the driving disc (47) through the adjusting ring I (474); and a second through hole (477) corresponding to the first through hole (473) is formed in the second adjusting ring (476).

6. A tennis ball serving device according to claim 2, wherein said second half wheel (42) is rotatably mounted on the outer periphery of said second half shaft (45) in a synchronized manner and is axially slidable relative to said second half shaft (45); a first stepped hole (421) for the connecting sleeve (431) to extend into is formed in the side, facing the first half shaft (43), of the second half wheel (42), and the end face of the connecting sleeve (431) is abutted against the bottom face of the first stepped hole (421) to realize axial rotation transmission; the half wheel II (42) is elastically pressed by a spring II (726) back to the half shaft I (43) side, and is used for pressing the end face of the connecting sleeve (431) and the bottom face of the stepped hole I (421).

7. A tennis ball serving device as claimed in claim 6, wherein the end surface of the connecting sleeve (431) and the bottom surface of the stepped hole are mutually matched inclined surfaces (422), and the end surface of the connecting sleeve (431) and the bottom surface of the stepped hole are mutually pressed and driven through the inclined surfaces (422).

8. A tennis ball serving device as claimed in claim 6, wherein the end surface of the connecting sleeve (431) and the bottom surface of the stepped hole are provided with end surface ratchets which are matched with each other, and the end surface of the connecting sleeve (431) and the bottom surface of the stepped hole are pressed against each other through the end surface ratchets for transmission.

9. A tennis ball serving device according to claim 2, wherein a support sleeve (48) is fixedly connected to an end of the second half wheel (42) away from the first half wheel (41), the support sleeve (48) is sleeved on the outer periphery of the second half wheel (45), a convex ring (481) is formed on an end surface of the support sleeve (48), a second transmission wheel (72) is arranged on one side of the support sleeve (48) away from the second half wheel (42), and the inner periphery of the second transmission wheel (72) is rotatably connected to the second half wheel (45) through a second rotary bearing (727); one side of the second driving wheel (72) facing the support sleeve (48) is provided with a first stepped hole (421), the inner periphery of the first stepped hole (421) is fixedly connected with a baffle ring (722), and a second spring (726) is elastically pressed between the baffle ring (722) and the convex ring (481).

10. A tennis ball serving device according to claim 9, wherein a driving sleeve (49) is fixedly connected to the periphery of said supporting sleeve (48), said driving sleeve (49) is used for moving to the second driving wheel (72) side, and friction transmission between the driving sleeve (49) and the second driving wheel (72) is realized; the second driving wheel (72) is connected with the first driving wheel (71) on the first rotating shaft (22) through a belt (73), so that the transmission of the first driving wheel (71) and the second driving wheel (72) is realized; the belt (73) is tensioned by a tensioning wheel (74).