Ball serving machine

Abstract

This invention provides a ball-launching machine, including a launching tube, an electromagnetic ejection mechanism, and a control mechanism. The launching tube has interconnected inlet and outlet channels. The electromagnetic ejection mechanism includes an outer cylinder, a stator unit, and a moving unit. The outer cylinder is connected to the launching tube. Both the stator unit and the moving unit are located inside the outer cylinder. The stator unit is fixedly connected to the outer cylinder, and the moving unit is movably connected to the outer cylinder and / or the stator unit. The moving unit can move along the axial direction of the outer cylinder. The control mechanism can output a variable frequency and variable voltage current to the stator unit, causing the stator unit to generate a moving traveling wave magnetic field. The traveling wave magnetic field interacts with the moving unit and generates an electromagnetic thrust to drive the moving unit to move towards the outlet channel. This ball-launching machine can achieve high-speed ball launching, high ball quality, and easy control.

Description

Technical Field

[0001] This invention relates to the field of training equipment technology, specifically to a ball-serving machine. Background Technology

[0002] The mainstream drive solutions for existing ball-serving machines (such as those used to launch tennis balls, table tennis balls, pickles, or badminton shuttlecocks) include dual-roller drive and compressed air drive, with the following specific characteristics: The dual-roller drive method uses two counter-rotating rollers to clamp and launch the ball, which has the advantages of controllable ball rotation and relatively stable trajectory; however, the dual-roller drive is difficult to achieve high ball speed and is prone to accelerating the wear of rollers and / or ball.

[0003] Compressed air drive accelerates the ball by releasing high-pressure gas instantaneously, which can achieve a high ball speed. However, compressed air drive is noisy and can easily interfere with the training environment. In addition, pressure fluctuations during the gas storage and release process may lead to insufficient ball speed and trajectory stability. Furthermore, compressed air drive requires precise timing coordination between gas supply and valve control, resulting in a complex and costly system. Summary of the Invention

[0004] The main objective of this invention is to provide a ball-serving machine that can achieve high-speed ball serving, high ball quality, and easy control.

[0005] To achieve the main objective of this invention, a ball-launching machine is provided, comprising a launching tube, an electromagnetic launching mechanism, and a control mechanism. The launching tube has interconnected ball-in channel and ball-out channel. The electromagnetic launching mechanism includes an outer cylinder, a stator unit, and a moving unit. The outer cylinder is connected to the launching tube. Both the stator unit and the moving unit are located inside the outer cylinder. The stator unit is fixedly connected to the outer cylinder, and the moving unit is movably connected to the outer cylinder and / or the stator unit. The moving unit can move along the axial direction of the outer cylinder. The control mechanism can output a variable frequency and variable voltage current to the stator unit, causing the stator unit to generate a moving traveling wave magnetic field. The traveling wave magnetic field interacts with the moving unit and generates an electromagnetic thrust to drive the moving unit to move towards the ball-out channel.

[0006] As can be seen from the above, the ball-serving machine is equipped with an electromagnetic catapult mechanism. The electromagnetic thrust generated by the electromagnetic catapult mechanism drives the moving sub-unit to move along a predetermined trajectory, so as to apply a high-speed impact force to the ball located in the ball release channel. Since the electromagnetic catapult mechanism can output high acceleration in a short stroke, the ball-serving machine can generate a sufficiently large impact thrust in a short distance, so that the ball release speed reaches or exceeds the serving speed of an excellent athlete.

[0007] A further design includes a main spindle platform at one end of the launching tube, an outer cylinder mounted on the main spindle platform, a rotating shaft on the main spindle platform perpendicular to the axial direction, and a column and a first drive mechanism. The rotating shaft is rotatably connected to the column, the first drive mechanism drives the main spindle platform to rotate, and the control mechanism is electrically connected to the first drive mechanism.

[0008] As can be seen from the above, the main spindle table can achieve high-precision alignment and assembly of the launching tube and the outer cylinder, ensuring the coaxiality of the motion trajectory of the moving sub-unit and the ball launching channel, thereby ensuring accurate firing of the ball in the ball launching channel; on the other hand, through the linkage of the main spindle table, the column and the first drive mechanism, the launching tube and the electromagnetic catapult unit can be driven to adjust the angle around the axis of rotation, so as to adjust the pitch position of the ball launch as needed, thereby improving the practicality and functionality of the ball launching machine.

[0009] A preferred embodiment is that the stator unit is cylindrical and the mover unit is shaft-shaped, with the stator unit sleeved on the mover unit.

[0010] As can be seen from the above, this design helps to simplify the structure of the electromagnetic catapult mechanism, reduce assembly difficulty, and lower costs.

[0011] A further proposed solution is that the stator unit includes multiple first stator modules and multiple isolation modules, which are arranged alternately. The first stator module includes a first iron core assembly and a coil, with the coil wound on the first iron core assembly in a three-phase six-pole configuration. The isolation module includes an isolation ring and a magnetic guide ring, with the magnetic guide ring located on the inner ring of the isolation ring. The mover unit includes a hollow tube and multiple sets of magnetic tile groups circumferentially distributed around the hollow tube. Each set of magnetic tile groups includes multiple S-pole magnetic tiles and multiple N-pole magnetic tiles, which are arranged alternately, with adjacent sets of magnetic tile groups staggered from each other.

[0012] As can be seen above, when a symmetrical sinusoidal current is simultaneously applied to the three-phase windings of the stator unit or a DC current is applied using a three-phase six-step commutation method, the traveling wave magnetic field generated by the windings interacts with the permanent magnet magnetic field formed by the magnetic tile assembly of the mover unit. This forces the mover unit to move axially in the outer shell at a corresponding speed and direction, thereby applying a precise impact force to the ball in the ball launch channel. The control mechanism can adjust parameters such as the target azimuth angle, pitch angle, and electromagnetic thrust according to preset requirements. By precisely adjusting the electrical parameters such as the frequency, voltage amplitude, and phase of the three-phase AC current of the coil windings, the change law of the magnetic field is controlled, thereby controlling the movement speed, thrust magnitude, and stroke of the mover unit to achieve precise firing of the ball.

[0013] A further improvement is to have end caps at both ends of the hollow tube, with guide rollers rotatably mounted on the end caps, and the guide rollers contacting the inner wall of the outer cylinder.

[0014] As can be seen from the above, the design of the end cap and its guide rollers can help the moving unit move more smoothly and reliably in the axial direction of the housing, while ensuring the effectiveness and stability of the stator unit's drive on the moving unit.

[0015] Another preferred embodiment is that the stator unit includes multiple sets of second stator modules, each second stator module including a magnetic steel ring and a coil. The magnetic steel ring has an annular groove, and the coil is located in the annular groove. The mover unit includes a hollow magnetic tube, the outer periphery of which is provided with a copper or aluminum sleeve. The mover unit can extend through the main spindle table into the ejection channel.

[0016] As can be seen from the above, when a symmetrical sinusoidal current is simultaneously applied to the three-phase windings of the stator unit or a DC current is applied using a three-phase six-step commutation method, the stator unit generates a traveling wave magnetic field. Under the action of electromagnetic induction, the moving unit will reciprocate along the axial direction of the outer shell at a certain slip velocity, thereby applying a precise impact force to the ball in the ball launch channel. The control mechanism can adjust parameters such as the target azimuth angle, pitch angle, and electromagnetic thrust according to preset requirements. By precisely adjusting the electrical parameters such as the frequency, voltage amplitude, and phase of the three-phase AC current of the coil windings, the magnetic field variation law is controlled, thereby controlling the movement speed, thrust magnitude, and stroke of the moving unit to achieve precise firing of the ball.

[0017] Another preferred embodiment is that the stator unit includes two sets of spaced-apart third stator modules. Each third stator module includes a second core assembly, a coil, and a drive plate. The second core assembly includes multiple axially distributed bosses, with the coil wound around each boss. The drive plate is electrically connected to the coil and the control mechanism, respectively. The mover unit includes a trolley and a wheel assembly. The trolley is located between the two sets of third stator modules. One end of the trolley facing the main shaft is provided with an impact head. The wheel assembly is mounted on the trolley and connected to an axially extending guide rail provided inside the outer cylinder. The mover unit also includes an S-pole magnet and an N-pole magnet. The S-pole magnet and the N-pole magnet are located on opposite sides of the trolley and are respectively positioned opposite one set of third stator modules. Alternatively, the trolley may be made of copper or aluminum.

[0018] As can be seen from the above, when a three-phase symmetrical sinusoidal current is passed through the three-phase winding of the stator unit, an air gap magnetic field (i.e., a traveling wave magnetic field) will be generated. Without considering the longitudinal end effect caused by the disconnection at both ends of the second iron core assembly, the distribution of the air gap magnetic field can be regarded as a sinusoidal distribution along the axial direction of the outer cylinder. When the three-phase current changes with time, the air gap magnetic field will move in a straight line according to the A, B, C phase sequence. The excitation magnetic field generated by the S-pole magnet and N-pole magnet on the mover unit interacts with the traveling wave magnetic field to generate an electromagnetic thrust. Under the action of this electromagnetic thrust, since the stator is fixed, the mover unit will move in a straight line along the direction of the traveling wave magnetic field.

[0019] A further proposed solution is to have an impact hammer and an elastic element on the main spindle platform. The impact hammer is slidably connected to the main spindle platform along the axial direction. The impact hammer includes a pushing part located in the ejection channel and a pushed part located in the outer cylinder. The moving part can impact the pushed part, and the elastic element forces the impact hammer to move into the outer cylinder.

[0020] As can be seen from the above, this design eliminates the need for the moving sub-unit to penetrate into the launch channel, which helps to reduce the size and volume of the moving sub-unit and optimize the structure of the ball launcher.

[0021] A further proposed solution is to install a pressure sensor on the launch tube, with the detection end of the pressure sensor facing the goal channel. The pressure sensor and the goal channel are located on opposite sides of the launch channel. The ball machine also includes a latch mechanism, a base, and a second drive mechanism. The latch mechanism includes a tongue and a first drive unit. The tongue is axially slidably mounted on the main shaft. The first drive unit can drive the tongue to insert into the goal channel. The first drive unit is electrically connected to the control mechanism. The column is mounted on the base and rotates around its own axis. The second drive mechanism can drive the column to rotate. The second drive mechanism is electrically connected to the control mechanism.

[0022] As can be seen from the above, the pressure sensor serves two purposes: firstly, it detects the presence of a ball in the launch channel, allowing the control mechanism to release the balls one by one via the latch mechanism, ensuring only one ball remains in the launch channel; secondly, the ball pressure value measured by the pressure sensor can be used to adjust and correct the electromagnetic thrust. Furthermore, the second drive mechanism rotates the column, enabling automatic adjustment of the ball's circumferential launch orientation, enriching the ball-launching machine's functionality and enhancing its practicality.

[0023] A further proposed solution is that the ball-serving machine also includes a ball-spinning mechanism, a speed sensor, and a detection sensor. The ball-spinning mechanism includes a sleeve, a second drive unit, and two sets of rotating units. The sleeve is rotatably mounted on the exit end of the launching tube. The second drive unit can drive the sleeve to rotate and is electrically connected to the control mechanism. The rotating unit includes a rolling roller and a first motor. A portion of the rolling roller extends into the sleeve. The first motor drives the rolling roller to rotate and is electrically connected to the control mechanism. The rolling rollers of the two sets of rotating units are symmetrically arranged on opposite sides of the sleeve. The speed sensor is installed at the exit end of the sleeve and is electrically connected to the control mechanism. The detection sensor is also electrically connected to the control mechanism and is used to detect the phase of the traveling wave magnetic field.

[0024] As can be seen from the above, the ball-spinning mechanism enables the launched ball to rotate in a specific direction, better simulating real-world conditions and significantly improving the practical performance of the ball-launching machine. The speed sensor monitors the ball's launch speed in real time, providing accurate feedback data for the control mechanism to adjust the electromagnetic catapult. The detection sensor monitors the phase change of the traveling wave magnetic field, ensuring the control mechanism can precisely control the timing of the launch. Attached Figure Description

[0025] Figure 1 This is a structural diagram of the first omitted component of the ball-serving machine according to the first embodiment of the present invention.

[0026] Figure 2 This is a structural diagram of the second omitted component of the first embodiment of the ball-serving machine of the present invention.

[0027] Figure 3 This is a cross-sectional view of the second omitted component of the first embodiment of the ball-serving machine of the present invention.

[0028] Figure 4 This is a structural diagram of the electromagnetic catapult mechanism of the first embodiment of the ball-launching machine of the present invention, with some components omitted.

[0029] Figure 5 This is a structural diagram of the first stator module of the first embodiment of the ball-launching machine of the present invention.

[0030] Figure 6 This is a structural diagram of the isolation module of the first embodiment of the ball-serving machine of the present invention.

[0031] Figure 7 This is a structural diagram of the moving part of the ball-serving machine according to the first embodiment of the present invention.

[0032] Figure 8 yes Figure 3 Enlarged view of point D in the middle.

[0033] Figure 9 This is a structural diagram of the sensor isolation ring and Hall plate of the first embodiment of the ball-serving machine of the present invention.

[0034] Figure 10 This is a structural diagram of the electromagnetic catapult mechanism of the second embodiment of the ball-launching machine of the present invention, with the first part of the components omitted.

[0035] Figure 11 This is a structural diagram of the electromagnetic catapult mechanism of the second embodiment of the ball-launching machine of the present invention, with the second part of the component omitted.

[0036] Figure 12 This is a structural diagram of the second stator module of the second embodiment of the ball-launching machine of the present invention.

[0037] Figure 13 This is a structural diagram of the electromagnetic catapult mechanism of the third embodiment of the ball-launching machine of the present invention, with the first part of the components omitted.

[0038] Figure 14 This is a structural diagram of the electromagnetic catapult mechanism of the third embodiment of the ball-launching machine of the present invention, with the second omitted component.

[0039] Figure 15 This is a structural diagram of the moving part of the ball-serving machine according to the third embodiment of the present invention.

[0040] The present invention will be further described below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0041] First embodiment of ball-serving machine Reference Figure 1 The ball-launching machine 100 includes a launching tube 1, a column 21, a base 22, an electromagnetic catapult mechanism 3, a latch mechanism 4, a ball-spinning mechanism 5, a first drive mechanism 61, a second drive mechanism 62, a control mechanism 63, a speed sensor 71, and a detection sensor 72.

[0042] Combination Figure 2 and Figure 3 The launching tube 1 is provided with a ball-in channel 11 and a ball-out channel 12, and the ball-in channel 11 and the ball-out channel 12 are connected to each other. The ball-in channel 11 allows the ball 10 to enter the ball-out channel 12, and the ball-out channel 12 is used to guide and limit the ball 10 so that the ball 10 can be launched by the electromagnetic catapult mechanism 3.

[0043] A main spindle platform 13 is provided at the end of the launching tube 1 away from the launching port of the launching channel 12. The main spindle platform 13 has a rotating shaft, which allows the launching tube 1 to be rotatably connected to the column 21 via the rotating shaft; wherein, the rotating shaft is perpendicular to the axis of the launching tube 1. The first drive mechanism 61 is used to drive the main spindle platform 13 to rotate relative to the column 21, so that the launching tube 1 can adjust its pitch angle around the rotating shaft, thereby flexibly adjusting the pitch position of the ball 10 to meet the serving angle requirements in different training scenarios. Preferably, the first drive mechanism 61 includes a first transmission wheel set 611 and a second motor. The input wheel of the first transmission wheel set 611 is connected to the drive shaft of the second motor, and the output wheel of the first transmission wheel set 611 is connected to the rotating shaft; the first transmission wheel set 611 is preferably a gear set, and the second motor is preferably a servo motor or a stepper motor to precisely adjust the pitch angle of the launching tube 1. The second motor is electrically connected to the control mechanism 63, so that the control mechanism 63 can precisely control the start, stop, and rotation of the second motor.

[0044] The column 21 is rotatably mounted on the base 22 around its own axis. A second drive mechanism 62 drives the column 21 to rotate and is electrically connected to the control mechanism 63. The second drive mechanism 62 includes a second transmission wheel set 621 and a third motor. The input wheel of the second transmission wheel set 621 is connected to the drive shaft of the third motor, and the output wheel of the second transmission wheel set 621 is coaxially arranged with and fixedly connected to the column 21. By driving the column 21 to rotate through the second drive mechanism 62, the circumferential direction of the ball 10's launch can be automatically adjusted, enriching the functions of the ball launcher 100 and improving its practicality. Preferably, the second transmission wheel set 621 is a gear set, and the third motor is preferably a servo motor or a stepper motor to precisely adjust the circumferential direction of the launch tube 1. The third motor is electrically connected to the control mechanism 63, enabling the control mechanism 63 to precisely control the start, stop, and rotation of the third motor.

[0045] Combination Figure 4 The electromagnetic catapult mechanism 3 includes an outer cylinder 31, a stator unit 32, and a mover unit 33. The outer cylinder 31 is connected to the main shaft 13 of the launching tube 1 to achieve high-precision alignment and assembly between the outer cylinder 31 and the launching tube 1, ensuring their coaxiality. This, in turn, ensures the coaxiality of the movement trajectory of the mover unit 33 with the ball release channel, enabling the ball 10 in the ball release channel to be accurately launched. Simultaneously, it reduces the assembly difficulty and complexity of both components. The outer cylinder 31 is preferably made of aluminum alloy, and a thin-walled carbon steel layer is preferably provided on the outer periphery of the outer cylinder 31 to achieve magnetic shielding.

[0046] Both the stator unit 32 and the mover unit 33 are located inside the outer cylinder 31. The stator unit 32 is fixedly connected to the outer cylinder 31, while the mover unit 33 is movably connected to the outer cylinder 31 and / or the stator unit 32, allowing the mover unit 33 to move along the axial direction of the outer cylinder 31. The axial direction of the outer cylinder 31 is parallel to the axial direction of the transmitting tube 1. The stator unit 32 is electrically connected to the control mechanism 63, enabling the control mechanism 63 to output a variable frequency and variable voltage current to the stator unit 32. This causes the stator unit 32 to generate a traveling wave magnetic field that moves along the axial direction of the outer cylinder 31. This traveling wave magnetic field interacts with the mover unit 33 and generates an electromagnetic thrust that drives the mover unit 33 to move towards the emission channel 12.

[0047] In this embodiment, the stator unit 32 is cylindrical, while the mover unit 33 is shaft-shaped, and the stator unit 32 is sleeved on the mover unit 33. This design helps simplify the structure of the electromagnetic catapult mechanism 3, reducing assembly difficulty and cost. The stator unit 32 includes multiple first stator modules 321 and multiple isolation modules 322, which are arranged alternately in the axial direction of the outer cylinder 31, with adjacent first stator modules 321 and isolation modules 322 being adjacent to each other. The mover unit 33 includes a hollow tube 331 and multiple sets of magnetic tile groups 332, which are circumferentially distributed around the hollow tube 331, with adjacent sets of magnetic tile groups 332 being adjacent to each other.

[0048] Combination Figure 5 The first stator module 321 includes a first core assembly 3211 and a coil 3212. The coil 3212 is wound on the first core assembly 3211 in a three-phase, six-pole configuration. The number of pole pairs can be increased appropriately based on the thrust required by the electromagnetic catapult mechanism 3. In this embodiment, the number of first stator modules 321 is six. However, it is understood that in other embodiments, the number of first stator modules 321 may be four or other numbers. The number of first stator modules 321 can be increased or decreased according to the thrust required by the electromagnetic catapult mechanism 3.

[0049] Combination Figure 6 The isolation module 322 includes an isolation ring 3221 and a magnetic ring 3222, with the magnetic ring 3222 disposed within the inner ring of the isolation ring 3221. Preferably, the outer diameter of the isolation ring 3221 is equal to the outer diameter of the first core assembly 3211, and preferably, the inner diameters of the isolation ring 3221, the magnetic ring 3222, and the first core assembly 3211 are also equal. Preferably, the number of isolation modules 322 is one less than the number of first stator modules 321. Combination Figure 7 The magnetic tile group 332 includes multiple N-pole magnetic tiles 3321 and multiple S-pole magnetic tiles 3322. These N-pole and S-pole magnetic tiles 3321 are arranged alternately along the axial direction of the outer cylinder 31, with an adjacent N-pole magnetic tile 3321 and an adjacent S-pole magnetic tile 3322 being adjacent to each other. Furthermore, adjacent groups of magnetic tile groups 332 are staggered; for example, along the axial direction of the outer cylinder 31, adjacent groups of magnetic tile groups 332 are staggered by one-third of the magnet pole pitch. It is understood that the staggered distance between adjacent groups of magnetic tile groups 332 can be changed according to design requirements. Moreover, the number of magnetic tile groups 332 is equal to the number of pole pairs in the first stator module 321. For example, in this embodiment, both the number of pole pairs in the first stator module 321 and the number of magnetic tile groups 332 are 12. Multiple groups of magnetic tile groups 332 cover the surface of the hollow tube 331 along its circumference.

[0050] Furthermore, carbon fiber is wound around the outer diameter surface of the magnetic tile assembly 332 to enhance the adhesion of the magnet assembly and to protect the magnetic tile.

[0051] Both ends of the hollow tube 331 are provided with end caps 333, and multiple guide rollers 3331 are rotatably mounted on the end caps 333. The guide rollers 3331 contact the inner wall of the outer cylinder 31. Through the design of the end caps 333 and the guide rollers 3331 thereon, the moving unit 33 can be assisted to move more smoothly and reliably in the axial direction of the outer shell, while ensuring the effectiveness and stability of the stator unit 32 driving the moving unit 33. Preferably, an electromagnetic air gap of about 1 mm is maintained between the outer diameter of the magnetic tile assembly 332 and the inner diameter of the first iron core assembly 3211; the hollow tube 331 is made of hollow aluminum tube.

[0052] In this embodiment, the main spindle platform 13 is also provided with an impact hammer 131 and an elastic element 132. The impact hammer 131 is slidably connected to the main spindle platform 13 along the axial direction of the outer cylinder 31. The impact hammer 131 includes a pushing part 1311 and a pushed part 1312. The pushing part 1311 is located inside the ejection channel 12. Preferably, when the impact hammer 131 is in the initial state, the side of the impact hammer 131 facing the ejection channel 12 is flush with the inner wall of the launching tube 1, and the pushed part 1312 extends into the outer cylinder 31. The elastic element 132 is used to force the impact hammer 131 to move towards the electromagnetic catapult mechanism 3, so that the pushed part 1312 extends into the electromagnetic catapult mechanism 3, so that the moving part 33 can strike the pushed part 1312, thereby pushing the impact hammer 131 to move into the ejection channel 12 and strike the ball 10, so that the ball 10 is launched from the ejection channel 12. By setting the impact hammer 131 on the main spindle 13, the moving part 33 does not need to penetrate into the launch channel 12, which helps to reduce the size and volume of the moving part 33 and optimize the structure of the ball launching machine 100. Furthermore, an impact head 3332 is formed protruding from the end cap 333 near the impact hammer 131 towards the push part 1312. This design helps to reduce the size of the impact hammer 131, improve the structural strength of the impact hammer 131, prevent the impact hammer 131 from deforming during impact and movement, and ensure the reliability and stability of the ball launching 10.

[0053] The principle of the electromagnetic catapult mechanism 3 in this embodiment will be briefly described below: Reference Figure 5When the coils 3212 are arranged in a circumferential order according to abcabc and the three-phase windings are connected in a Y-type configuration, after a symmetrical sinusoidal current is simultaneously applied to the three-phase windings of the coils 3212 of the stator unit 32 or a DC current is applied using a three-phase six-step commutation method, the traveling wave magnetic field generated by the stator unit 32 interacts with the permanent magnet magnetic field formed by the magnetic tile group 332 of the moving unit 33, thereby forcing the moving unit 33 to move in the axial direction of the outer shell at a corresponding speed and direction, so as to apply a precise impact force to the push part 1312 of the impact hammer 131, thereby causing the push part 1311 of the impact hammer 131 to strike the ball 10 and launch the ball 10 out of the launch tube 1.

[0054] The velocity of the moving subunit 33 Where τ is the permanent magnet pole pitch and f is the frequency of the alternating magnetic field. The operating equations of the electromagnetic catapult mechanism 3 are as follows: (1) Voltage balance equation: Where R is the winding resistance, L is the winding inductance, Ia is the winding current, and K is the winding current. E Let be the winding electromotive force coefficient, and x be the mover displacement.

[0055] (2) Force equilibrium equations: Where M is the mass of the moving part group, and F L denoted as ρ, where ρ is the load force and c is the viscous damping coefficient.

[0056] (3) Equation of electromagnetic force: Where m is the number of phases of the driver, N1 is the number of turns, p is the number of pole pairs, and τ is the permanent magnet pole pitch. It is the phase angle of the current (i.e., the angle between the no-load electromotive force E of a single coil and the phase current Ia). The amplitude (Wb) of the unloaded magnetic flux of a single coil.

[0057] The control mechanism 63 can adjust parameters such as target azimuth angle, pitch angle, and electromagnetic thrust according to preset requirements. By precisely adjusting the electrical parameters such as frequency, voltage amplitude, and phase of the three-phase AC current of the coil winding, it can regulate the magnetic field change law, thereby controlling the movement speed, thrust magnitude, and stroke of the moving subunit 33 to achieve precise firing of the sphere 10.

[0058] See Figure 3A pressure sensor 14 is provided on the launching tube 1, with its detection end facing the ball-in channel 11. The pressure sensor 14 and the ball-in channel 11 are located on opposite sides of the exit channel 12. The detection end of the pressure sensor 14 protrudes slightly from the inner wall of the exit channel 12, so that when the ball 10 enters the exit channel 12 from the ball-in channel 11, the ball 10 presses against the detection end of the pressure sensor 14, allowing the pressure sensor 14 to detect the pressure applied by the ball 10. The pressure sensor 14 is electrically connected to the control mechanism 63 to feed back the detection data to the control mechanism 63 for decision-making and control of other mechanisms.

[0059] As can be seen, the pressure value of the ball 10 measured by the pressure sensor 14 can be used to adjust and correct the electromagnetic thrust. In addition, the pressure sensor 14 can also be used to detect whether there is a ball 10 in the ejection channel 12, so that the control mechanism 63 can control the latch mechanism 4 to release the balls 10 one by one, ensuring that there is only one ball 10 in the ejection channel 12.

[0060] The latching mechanism 4 includes a tongue 41 and a first drive unit. The tongue 41 is slidably connected to the main spindle table 13 along the axial direction of the launching tube 1 to optimize the structure and layout of the latching mechanism 4. The first drive unit is mounted on the main spindle table 13 and drives the tongue 41 to slide so that it extends into or out of the ball-scoring channel 11, thereby realizing the directional control of the ball 10 in the ball-scoring channel 11. The first drive mechanism 61 is electrically connected to the control mechanism 63. The first drive mechanism 61 preferably includes a gear 421 and a fourth motor 422. The gear 421 is mounted on the drive shaft of the fourth motor 422. Correspondingly, the tongue 41 is provided with a rack structure 411, which meshes with the gear 421 so that the first drive unit can smoothly and reliably drive the tongue 41 to move precisely. The fourth motor 422 is preferably a servo motor or a stepper motor. Understandably, as an alternative, the first drive unit can also be an electric cylinder. In this case, the tongue 41 is not connected to the spindle table 13, but is directly mounted on the push rod of the electric cylinder.

[0061] The spinning mechanism 5 includes a sleeve 51, a second drive unit 52, and a rotating unit 53. The sleeve 51 is rotatably mounted on the exit end of the launching tube 1. The second drive unit 52 can drive the sleeve 51 to rotate and is electrically connected to the control mechanism 63. Preferably, the second drive unit 52 includes a third transmission wheel set 521 and a fifth motor 522. The input wheel of the third transmission wheel set 521 is connected to the output shaft of the fifth motor 522, and the output wheel of the third transmission wheel set 521 is mounted on the sleeve 51. The fifth motor 522 is mounted on the launching tube 1 so that the fifth motor 522 can drive the third transmission wheel set 521 to rotate the sleeve 51 relative to the launching tube 1. The fifth motor 522 is preferably a servo motor or a stepper motor.

[0062] Furthermore, combined Figure 8 The sleeve 51 is provided with a bearing assembly 511. Correspondingly, the launching tube 1 is provided with an annular groove 15. A part of the bearing of the bearing assembly 511 is embedded in the annular groove 15 and abuts against the bottom wall of the annular groove 15, so that the sleeve 51 can rotate smoothly relative to the launching tube 1.

[0063] There are two sets of rotating units 53. Each rotating unit 53 includes a rolling roller 531 and a first motor 532. A portion of the rolling roller 531 extends into the sleeve 51. The first motor 532 is mounted on the sleeve 51, and the rolling roller 531 is mounted on the drive shaft of the first motor 532. The rolling rollers 531 of the two sets of rotating units 53 are symmetrically arranged on opposite sides of the sleeve 51, and the rotation directions of the rolling rollers 531 of the two sets of rotating units 53 are opposite. The first motor 532 is preferably a servo motor or a stepper motor. By setting the ball-spinning mechanism 5 and designing it with its rotating units 53, the launched ball 10 can generate rotation in a specific direction, better simulating actual combat situations and significantly improving the practical performance of the ball-launching machine 100.

[0064] A speed sensor 71 is installed at the launch end of the sleeve 51 and is electrically connected to the control mechanism 63. The speed sensor 71 is used to monitor the launch speed of the ball 10 in real time and provide accurate feedback data for the control mechanism 63 to adjust the electromagnetic catapult mechanism 43.

[0065] The detection sensor 72 is mounted on the outer cylinder 31 of the electromagnetic catapult mechanism 3, and preferably located at the end of the outer cylinder 31 away from the main shaft table 13. The detection sensor 72 is electrically connected to the control mechanism 63. The detection sensor 72 is used to monitor the phase change of the traveling wave magnetic field in real time to ensure that the peak thrust is always in front of the mover unit 33 to achieve synchronous acceleration. At the same time, the output of the variable frequency power supply can be adjusted in time through phase comparison to prevent loss of synchronization, thereby achieving precise thrust phase control and closed-loop synchronous adjustment.

[0066] Combination Figure 9In this embodiment, the end of the stator unit 32 away from the main spindle stage 13 is provided with a sensor isolation ring 34 and a Hall plate 35. The Hall plate 35 is electrically connected to the control mechanism 63. The sensor isolation ring 34 and the Hall plate 35 are used to cooperate with the detection sensor 72 to achieve accurate monitoring of the phase change of the traveling wave magnetic field.

[0067] Furthermore, the ball-serving machine 100 provided by the present invention may also include a frame and a power supply unit, wherein the base 22 and the control mechanism 63 are both mounted on the frame, and the power supply unit is electrically connected to the control mechanism 63; furthermore, an automatic walking mechanism may also be provided on the frame, which is electrically connected to the control mechanism 63, so that the control mechanism 63 can control the automatic forming mechanism to perform automatic forming. Still further, the ball-serving machine 100 may also include a remote controller, which wirelessly communicates with the control mechanism 63, so that the user can control the ball-serving machine 100 to serve balls according to set parameters via the remote controller, and the ball-serving machine 100 can be moved along a set trajectory when the automatic walking mechanism is controlled by the remote controller.

[0068] In summary, the ball-serving machine 100, by configuring an electromagnetic catapult mechanism 3, utilizes the electromagnetic thrust generated by the electromagnetic catapult mechanism 3 to drive the moving subunit 33 along a predetermined trajectory, thereby applying a high-speed impact force to the ball 10 located in the ball-release channel. Because the electromagnetic catapult mechanism 3 can output high acceleration within a short stroke, the ball-serving machine 100 can generate a sufficiently large impact thrust within a short distance, enabling the ball 10 to reach or exceed the serving speed of an elite athlete. Furthermore, compared to the traditional dual-roller drive ball-serving machine 100, the ball-serving machine 100 provided by this invention, in addition to the advantages of controllable ball rotation and stable trajectory, can achieve high-speed serving and is less prone to wear on the ball 10. Compared to the traditional compressed air drive ball-serving machine 100, the ball-serving machine 100 provided by this invention operates with low noise, is less likely to interfere with the training environment, and has good ball speed and trajectory stability. It does not require precise timing coordination, simplifies the system, reduces costs, and further reduces the size and weight of the ball-serving machine 100, improving its portability and mobility.

[0069] It should be noted that the ball serving machine 100 provided by the present invention can be used with balls 10 including but not limited to tennis balls, table tennis balls, pickles, and badminton shuttlecocks.

[0070] Second embodiment of the ball-serving machine The difference between this embodiment and the first embodiment of the ball-launching machine lies in the structure of the electromagnetic catapult mechanism. Specifically, in this embodiment: Combination Figure 10The outer cylinder 31 of the electromagnetic catapult mechanism 3 is made of carbon steel; the stator unit 32 includes multiple sets of second stator modules 323, which are distributed along the axial direction of the outer cylinder 31, and adjacent sets of second stator modules 323 are adjacent to each other. Similarly, the stator unit 32 is fixedly connected to the outer cylinder 31.

[0071] Combination Figure 11 The second stator module 323 includes a magnetic steel ring 3231 and a coil 3212. The magnetic steel ring 3231 has an annular groove 15, and the coil 3212 is disposed within the annular groove 15. In this example, the number of second stator modules 323 is 12, but it is understood that the number of second stator modules 323 can be adjusted according to the thrust required by the electromagnetic catapult mechanism 3, such as 3, 6, 9, etc. The coil windings adopt a three-phase star connection.

[0072] Combination Figure 12 The moving part 33 includes a hollow magnetic tube 334, which is preferably made of hollow magnetic steel. The outer periphery of the hollow magnetic tube 334 is provided with a copper sleeve 335 or an aluminum sleeve.

[0073] Preferably, both ends of the hollow magnetic tube 334 are provided with end caps 333. In this embodiment, the end caps 333 are no longer provided with guide rollers 3331 and impact heads 3332. In addition, in this embodiment, the moving sub-unit 33 can extend through the main shaft 13 into the ejection channel 12. Correspondingly, the end of the outer cylinder 31 is provided with multiple guide wheels 311. The guide wheels 311 are adjacent to the copper sleeve 335 or aluminum sleeve to assist the moving sub-unit 33 in moving smoothly. It can be understood that, based on this embodiment, the moving sub-unit 33 can extend through the main shaft 13 into the ejection channel 12. Therefore, the main shaft 13 is no longer provided with impact hammers 131 and elastic elements 132. Instead, a through hole is directly provided for the moving sub-unit 33 to pass through, so that the moving sub-unit 33 can directly apply impact force to the ball 10.

[0074] The principle of the electromagnetic catapult mechanism 3 in this embodiment will be briefly described below: When a symmetrical sinusoidal current is simultaneously applied to the three-phase windings of the stator unit 32 coil 3212 or a DC current is applied using a three-phase six-step commutation method, the stator unit 32 generates a traveling wave magnetic field. Under the action of electromagnetic induction, the moving unit 33 will reciprocate along the axial direction of the outer shell at a certain slip velocity, thereby applying a precise impact force to the ball 10 in the ball outlet channel.

[0075] The velocity of the moving subunit 33 Where τ is the permanent magnet pole pitch and f is the frequency of the alternating magnetic field. The operating equations of the electromagnetic catapult mechanism 3 are as follows: (1) Voltage balance equation: Where R is the winding resistance, L is the winding inductance, Ia is the winding current, and K is the winding current. E Let be the winding electromotive force coefficient, and x be the mover displacement.

[0076] (2) Force equilibrium equations: Where M is the mass of the moving part group, and F L denoted as ρ, where ρ is the load force and c is the viscous damping coefficient.

[0077] (3) Equation of electromagnetic force: Where m is the number of phases of the driver, N1 is the number of turns, p is the number of pole pairs, and τ is the permanent magnet pole pitch. It is the phase angle of the current (i.e., the angle between the no-load electromotive force E of a single coil and the phase current Ia). The amplitude (Wb) of the unloaded magnetic flux of a single coil.

[0078] The control mechanism 63 can adjust parameters such as target azimuth angle, pitch angle, and electromagnetic thrust according to preset requirements. By precisely adjusting the electrical parameters such as frequency, voltage amplitude, and phase of the three-phase AC current of the coil winding, it can regulate the magnetic field change law, thereby controlling the movement speed, thrust magnitude, and stroke of the moving subunit 33 to achieve precise firing of the sphere 10.

[0079] In the first embodiment of the ball-launching machine, a permanent magnet is installed on the mover unit 33. Thrust is generated through the interaction between the permanent magnet's magnetic field and the traveling wave magnetic field of the stator unit 32. A potential drawback of this design is that the permanent magnet may experience a decrease in magnetic field strength or loss of magnetic energy during prolonged operation under high-impact conditions. However, the first embodiment of the ball-launching machine essentially involves the movement of the permanent magnet of the mover unit 33 and the moving traveling wave magnetic field cylinder, thus providing greater driving capability. In this embodiment, the mover unit 33 uses a hollow magnetic tube 334 and a copper sleeve 335 (or an aluminum sleeve) in a mating structure, without a permanent magnet. It is based on electromagnetic induction and is asynchronous with the traveling wave magnetic field generated by the stator unit 32, resulting in slippage. Within a certain range, the larger the slippage, the stronger the induced eddy currents on the mover surface, and the greater the generated electromagnetic driving force. The electromagnetic ejection mechanism 3 in this embodiment is designed to induce eddy currents on the mover surface using the traveling wave magnetic field, thereby generating a Lorentz force to drive the mover in reciprocating motion. Because the mover unit 33 does not contain permanent magnets, the problem of permanent magnet demagnetization is avoided, thus improving reliability.

[0080] Third embodiment of the ball-serving machine The difference between this embodiment and the first embodiment of the ball-launching machine lies in the structure of the electromagnetic catapult mechanism. Specifically, in this embodiment: Combination Figure 13The electromagnetic catapult mechanism 3 comprises two spaced-apart third stator modules 324, each including a second core assembly 3241, a coil 3212, and a drive plate 3242. Combined with... Figure 14 The second core assembly 3241 includes multiple axially distributed bosses 32411, with coils 3212 wound around each boss 32411. The bosses 32411 of the two sets of third stator modules 324 are arranged facing each other. The second core assembly 3241 of the two sets of third stator modules 324 is located between the drive plates 3242 of the two sets of third stator modules 324. The drive plates 3242 are electrically connected to the coils 3212 and the control mechanism 63, respectively. The second core assembly 3241 is made of laminated silicon steel sheets, and the coil windings are three-phase Y-connected.

[0081] Combination Figure 15 The moving unit 33 includes a trolley 336, a wheel assembly 337, an S-pole magnet 338, and an N-pole magnet. The trolley 336 is located between two sets of third stator modules 324, and an impact head 33361 is provided at the end of the trolley 336 facing the main shaft table 13. The wheel assembly 337 is mounted on the trolley 336, and there are two sets of wheel assemblies 337. The outer cylinder 31 is provided with a guide rail 312 extending axially along the outer cylinder 31 at each set of wheel assemblies 337. The wheel assembly 337 is connected to the guide rail 312, so that the trolley 336 can slide axially on the outer cylinder 31 through the cooperation of the wheel assembly 337 and the guide rail 312. The S-pole magnet 338 and the N-pole magnet are located on opposite sides of the trolley 336, and the S-pole magnet 338 and the N-pole magnet are respectively positioned opposite one set of third stator modules 324. The distribution directions of the S-pole magnet 338 and the N-pole magnet, the distribution directions of the two sets of wheel sets 337, and the axial direction of the outer cylinder 31 are preferably perpendicular to each other; the S-pole magnet 338 and the N-pole magnet are preferably both neodymium iron boron magnets.

[0082] The principle of the electromagnetic catapult mechanism 3 in this embodiment will be briefly described below: When a three-phase symmetrical sinusoidal current is passed through the three-phase winding of the coil 3212 of the stator unit 32, an air gap magnetic field (i.e., a traveling wave magnetic field; the air gap magnetic field of a linear motor translates along a straight line, hence the name traveling wave magnetic field) is generated. Without considering the longitudinal end effect caused by the disconnection at both ends of the second core assembly 3241, the distribution of this air gap magnetic field can be regarded as a sinusoidal distribution along the axial direction of the outer cylinder 31. When the three-phase current changes with time, the air gap magnetic field will move in a straight line according to the A, B, C phase sequence. The excitation magnetic field generated by the S pole magnet 338 and the N pole magnet on the mover unit 33 interacts with the traveling wave magnetic field to generate an electromagnetic thrust. Under the action of this electromagnetic thrust, since the stator is fixed, the mover unit 33 will move in a straight line along the direction of the traveling wave magnetic field.

[0083] The velocity of the moving subunit 33 Where τ is the permanent magnet pole pitch and f is the frequency of the alternating magnetic field. The operating equations of the electromagnetic catapult mechanism 3 are as follows: (1) Force balance equation: Where M is the mass of the moving part group, and F L denoted as ρ, where ρ is the load force and c is the viscous damping coefficient.

[0084] (2) Electromagnetic force equation: ; where n p The number of polar logarithms, τ is the polar moment, Ψ f i represents the flux linkage component of the permanent magnet on the direct axis of the stator winding. sq Let be the current on the q-axis.

[0085] Among them, the thrust of the linear permanent magnet synchronous drive is only proportional to the amplitude of the armature quadrature axis current. As long as the current amplitude and phase of the stator unit 32 are well controlled in the control mechanism 63, satisfactory thrust control characteristics can be obtained.

[0086] It should be noted that in other embodiments, the trolley 336 in this embodiment can be made of copper or aluminum, and the S-pole magnet 338 and N-pole magnet in this embodiment can be removed, making it a double-sided induction electromagnetic drive trolley, which can avoid potential demagnetization problems.

[0087] Finally, it should be emphasized that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A ball-serving machine, characterized in that, include: The launching tube is provided with an interconnected ball-in channel and a ball-out channel; An electromagnetic catapult mechanism includes an outer cylinder, a stator unit, and a moving unit. The outer cylinder is connected to the launch tube. The stator unit and the moving unit are both located inside the outer cylinder. The stator unit is fixedly connected to the outer cylinder, and the moving unit is movably connected to the outer cylinder and / or the stator unit. The moving unit can move along the axial direction of the outer cylinder. The control mechanism can output variable frequency and variable voltage current to the stator unit, so that the stator unit generates a moving traveling wave magnetic field. The traveling wave magnetic field interacts with the mover unit and generates electromagnetic thrust to drive the mover unit to move towards the emission channel.

2. The ball-serving machine according to claim 1, characterized in that: One end of the launching tube is provided with a main shaft platform, the outer cylinder is mounted on the main shaft platform, the main shaft platform is provided with a rotating shaft, and the rotating shaft is perpendicular to the axis; The ball-launching machine also includes a column and a first drive mechanism. The rotating shaft is rotatably connected to the column. The first drive mechanism drives the main shaft table to rotate. The control mechanism is electrically connected to the first drive mechanism.

3. The ball-serving machine according to claim 2, characterized in that: The stator unit is cylindrical; The moving part is axial, and the stator is sleeved on the moving part.

4. The ball-serving machine according to claim 3, characterized in that: The stator unit includes multiple first stator modules and multiple isolation modules, which are arranged alternately. Each first stator module includes a first core assembly and a coil, which is wound on the first core assembly in a three-phase six-pole manner. Each isolation module includes an isolation ring and a magnetic ring, with the magnetic ring disposed in the inner ring of the isolation ring. The moving unit includes a hollow tube and multiple sets of magnetic tile groups distributed circumferentially around the hollow tube. Each set of magnetic tile groups includes multiple S-pole magnetic tiles and multiple N-pole magnetic tiles, which are arranged alternately, with adjacent sets of magnetic tile groups being staggered.

5. The ball-serving machine according to claim 4, characterized in that: Both ends of the hollow tube are provided with end caps, and guide rollers are rotatably mounted on the end caps. The rotation axis of the guide rollers is parallel to the rotating shaft, and the guide rollers are in contact with the inner wall of the outer cylinder.

6. The ball-serving machine according to claim 3, characterized in that: The stator unit includes multiple sets of second stator modules. Each second stator module includes a magnetic steel ring and a coil. The magnetic steel ring is provided with an annular groove, and the coil is disposed in the annular groove. The moving part includes a hollow magnetic tube, and the outer periphery of the hollow magnetic tube is provided with a copper sleeve or an aluminum sleeve. The moving part can pass through the main shaft table and extend into the ejection channel.

7. The ball-serving machine according to claim 2, characterized in that: The stator unit includes two sets of spaced third stator modules. The third stator module includes a second core assembly, a coil, and a drive plate. The second core assembly includes a plurality of bosses distributed along the axial direction. The coil is wound around each of the bosses. The drive plate is electrically connected to the coil and the control mechanism, respectively. The moving unit includes a trolley and a wheel assembly. The trolley is located between the two sets of the third stator modules. An impact head is provided at one end of the trolley facing the main shaft table. The wheel assembly is mounted on the trolley and connected to a guide rail extending along the axial direction provided inside the outer cylinder. The moving unit also includes an S-pole magnet and an N-pole magnet, which are located on opposite sides of the trolley and respectively facing a set of the third stator modules, or The trolley is made of copper or aluminum.

8. The ball-serving machine according to claim 4, 5 or 7, characterized in that: The main shaft platform is provided with an impact hammer and an elastic element. The impact hammer is slidably connected to the main shaft platform along the axial direction. The impact hammer includes a pushing part located in the ejection channel and a receiving part located in the outer cylinder. The moving part can impact the receiving part, and the elastic element forces the impact hammer to move into the outer cylinder.

9. The ball-serving machine according to any one of claims 2 to 6, characterized in that: The launching tube is equipped with a pressure sensor, the detection end of which is positioned facing the ball-shooting channel. The pressure sensor and the ball-shooting channel are located on opposite sides of the launching channel. The ball-serving machine also includes a latch mechanism, a base, and a second drive mechanism. The latch mechanism includes a tongue and a first drive unit. The tongue is slidably mounted on the main shaft platform along the axial direction. The first drive unit can drive the tongue to be inserted into the ball-sinking channel. The first drive unit is electrically connected to the control mechanism. The column is rotatably mounted on the base around its own axis. The second drive mechanism can drive the column to rotate. The second drive mechanism is electrically connected to the control mechanism.

10. The ball-serving machine according to any one of claims 1 to 6, characterized in that: The ball-launching machine also includes: A ball-spinning mechanism includes a sleeve, a second drive unit, and two sets of rotating units. The sleeve is rotatably mounted on the exit end of the launching tube. The second drive unit can drive the sleeve to rotate and is electrically connected to the control mechanism. The rotating unit includes a rolling roller and a first motor. A portion of the rolling roller extends into the sleeve. The first motor drives the rolling roller to rotate and is electrically connected to the control mechanism. The rolling rollers of the two sets of rotating units are symmetrically arranged on opposite sides of the sleeve. A speed sensor is installed at the exit end of the sleeve and is electrically connected to the control mechanism. A detection sensor is mounted on the outer cylinder and electrically connected to the control mechanism. The detection sensor is used to detect the phase of the traveling wave magnetic field.

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