Ball launcher and rotor

Abstract

An object of the present invention is to provide a technology capable of suppressing wear of balls caused by rotors in a ball launching device that launches balls using the rotational force of multiple rotors. [Solution] In a ball launching device, at least one of the rotors has a rotor body supported on the main body of the ball launching device via a rotating shaft member, and an outer peripheral member formed of an elastic body and attached to the rotor body so as to cover the outer peripheral surface of the rotor body. In at least one rotor, the outer peripheral member is attached to the rotor body so that the outer peripheral portion, which is the portion of the outer peripheral member that covers the outer peripheral surface of the rotor body, is displaceable relative to the outer peripheral surface of the rotor body. Furthermore, a non-contact portion is formed on at least a portion of the outer peripheral surface of the rotor body that is not in contact with the inner peripheral surface of the outer peripheral member.

Description

[Technical Field]

[0001] The present invention relates to a ball launching device. [Background technology]

[0002] Conventionally, ball launching devices have been known that sandwich a ball between multiple rotors and launch the ball using the rotational force of the multiple rotors (see, for example, Patent Documents 1 to 3). Patent Document 1 discloses a pitching machine in which three pitching rotors are arranged in a Y-shape. In the pitching machine disclosed in Patent Document 1, the rotor shaft of the lower central rotor, which is located at the bottom of the three rotors, is attached to a rotor support structure via a cushioning device. The cushioning device is configured to be movable up and down relative to the rotor support structure.

[0003] Also, in the past, a ball launching device has been known in which the outer circumferential surface of the rotor is covered with an elastic body (see, for example, Patent Document 4). Patent Document 4 discloses a rotor in which the outer circumferential surface of a metal wheel is covered with urethane rubber. In the rotor disclosed in Patent Document 4, the urethane rubber ring is configured to be separable from the metal wheel. The urethane rubber ring is attached to the metal wheel and is held down by a ring-shaped urethane rubber retainer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-057544 [Patent Document 2] Special Publication No. 08-503390 [Patent Document 3] Japanese Utility Model Application Publication No. 02-114082 [Patent Document 4] Japanese Patent Application Laid-Open No. 2009-183379 Summary of the Invention [Problem to be solved by the invention]

[0005] In a ball launching device that launches a ball using the rotational force of multiple rotors, the ball is sent between the multiple rotors that are rotating at high speed when the ball is launched. The ball that is sandwiched between the multiple rotors is then launched from between the multiple rotors at a speed that corresponds to the rotational speed of the multiple rotors. At this time, the rotors slip on the surface of the ball until the moving speed of the ball sent between the multiple rotors reaches a speed that corresponds to the rotational speed of the rotors. This may cause the surface of the ball to rub against the rotors, resulting in wear of the ball.

[0006] The present invention was made in consideration of the above-mentioned problems, and its purpose is to provide a technology that can suppress wear on balls caused by rotors in a ball launching device that launches balls using the rotational force of multiple rotors. [Means for solving the problem]

[0007] A ball launching device according to a first aspect of the present invention is a ball launching device that sandwiches a ball between a plurality of rotors and launches the ball by the rotational force of the plurality of rotors, wherein at least one of the plurality of rotors has a rotor body supported on a main body of the ball launching device via a rotating shaft member, and an outer peripheral member formed of an elastic body and attached to the rotor body so as to cover the outer peripheral surface of the rotor body, and The outer peripheral member is attached to the rotor body so that the outer peripheral portion, which covers the circumferential surface, can be displaced relative to the outer peripheral surface of the rotor body, and a non-contact portion that is not in contact with the inner peripheral surface of the outer peripheral member is formed on at least a portion of the outer peripheral surface of the rotor body.

[0008] In a ball launching device according to a first aspect of the present invention, a plurality of rotors are supported on the main body of the ball launching device via a rotating shaft member, and a ball is caught between the rotors that rotate at high speed around the rotation axis of the rotating shaft member, and the ball is launched by the rotational force of the rotors.

[0009] At least one rotor among the multiple rotors has a rotor body and an outer circumferential member. The rotor body is supported on the main body of the ball launching device via a rotating shaft member. The outer circumferential member is formed of an elastic body. The outer circumferential member is attached to the rotor body so as to cover the outer circumferential surface of the rotor body. Therefore, in at least one rotor, the outer circumferential surface of the outer circumferential portion, which is the portion of the outer circumferential member that covers the outer circumferential surface of the rotor body, comes into contact with the ball. In other words, friction occurs between the outer circumferential surface of the outer circumferential portion of the outer circumferential member and the ball.

[0010] Here, the outer peripheral member is formed of an elastic material. The outer peripheral member is attached to the rotor body, but the outer peripheral portion of the outer peripheral member is displaceable relative to the outer peripheral surface of the rotor body. Therefore, when the balls come into contact with the outer peripheral surface of the outer peripheral member and friction occurs between them while the rotor is rotating at high speed, the outer peripheral portion of the outer peripheral member temporarily displaces relative to the outer peripheral surface of the rotor body in the opposite direction to the rotational direction of the rotor. When the outer peripheral portion of the outer peripheral member displaces in the opposite direction to the rotational direction of the rotor relative to the outer peripheral surface of the rotor body while in contact with the balls, the outer peripheral member is less likely to rub against the surface of the balls.

[0011] In addition, at least one rotor has a non-contact portion formed on at least a portion of the outer circumferential surface of the rotor body that is not in contact with the inner circumferential surface of the outer circumferential member. This makes it easier for the outer circumferential portion of the outer circumferential member to displace relative to the outer circumferential surface of the rotor body in the event of friction between the balls sandwiched between the rotors and the outer circumferential portion of the outer circumferential member. This further reduces the friction of the balls with the outer circumferential member.

[0012] Even if the outer periphery of the outer member is displaced relative to the outer periphery of the rotor body, the rotational force of the rotor increases the moving speed of the ball while the displaced outer periphery of the outer member is in contact with the ball.The ball is then launched from the ball launching device at a speed corresponding to the rotational speed of the rotor.Furthermore, when the ball is launched from the ball launching device and separated from the outer periphery of the outer member in at least one rotor, the displacement of the outer periphery of the outer member relative to the outer periphery of the rotor body is eliminated.

[0013] As described above, in the ball launching device according to the first aspect of the present invention, at least one rotor can suppress the rubbing of the surface of the ball by the rotor or the outer peripheral member of the rotor that occurs when a ball is caught between multiple rotors rotating at high speed, thereby suppressing wear of the ball by the rotor.

[0014] In the ball launching device according to the first aspect of the present invention, the non-contact portion may be formed by a through hole that penetrates from the outer peripheral surface to the inner peripheral surface of the rotor body in the at least one rotor. When such a through hole is provided in the rotor body, the opening of the through hole on the outer peripheral surface side of the rotor body becomes the non-contact portion.

[0015] Furthermore, when a non-contact portion is formed by such through holes, air is supplied from the inside of the rotor body through the through holes between the outer peripheral surface of the rotor body and the inner peripheral surface of the outer peripheral member. As a result, when an air layer is formed between the outer peripheral surface of the rotor body and the inner peripheral surface of the outer peripheral member, when friction occurs between the balls sandwiched between the multiple rotors and the outer peripheral portion of the outer peripheral member, the outer peripheral portion of the outer peripheral member becomes more likely to displace relative to the outer peripheral surface of the rotor body in at least one rotor. Therefore, rubbing of the ball surface by the outer peripheral member can be further suppressed.

[0016] Here, in the at least one rotor, a plurality of the through holes may be provided on the outer peripheral surface of the rotor body at approximately equal intervals in the circumferential direction, whereby when the rotor rotates, air supplied from the inside of the rotor body through the plurality of through holes can form an approximately uniform air layer in the circumferential direction between the outer peripheral surface of the rotor body and the inner peripheral surface of the outer peripheral member.

[0017] In the ball launching device according to the first aspect of the present invention, the non-contact portion may be formed by a plurality of recesses provided on the outer peripheral surface of the rotor body in the at least one rotor. When such a plurality of recesses is provided in the rotor body, the opening of each recess serves as the non-contact portion.

[0018] In a ball launching device according to a first aspect of the present invention, the non-contact portion may be formed by the fact that, in the at least one rotor, the cross-sectional shape of the outer surface of the rotor body in the direction of the rotational axis of the at least one rotor has a V-shape or a concave shape, and the cross-sectional shape of the outer portion of the outer member in the direction of the rotational axis of the at least one rotor is approximately linear.

[0019] In addition, in the ball launching device of the first aspect of the present invention, the cross-sectional shape of the outer surface of the rotor body in the direction of the rotation axis of the at least one rotor may be approximately linear, and the cross-sectional shape of the outer portion of the outer member in the direction of the rotation axis of the at least one rotor may be V-shaped or concave, thereby forming the non-contact portion.

[0020] In the ball launching device according to the first aspect of the present invention, in the at least one rotor, a portion of the outer peripheral member other than the outer peripheral portion, or a portion of the outer peripheral portion of the outer peripheral member other than a contact portion where the outer peripheral surface comes into contact with the ball, may be fixed to the rotor body. In this way, in at least one rotor, by fixing a predetermined portion of the outer peripheral member to the rotor body, it becomes possible to efficiently transmit the rotational force of the rotor body to the ball via the outer peripheral member. On the other hand, if the fixed position of the outer peripheral member to the rotor body is a portion other than the outer peripheral portion, the outer peripheral portion can be displaced relative to the outer peripheral surface of the rotor body. Furthermore, if the fixed position of the outer peripheral member to the rotor body is a portion other than a contact portion of the outer peripheral portion of the outer peripheral member, the contact portion of the outer peripheral portion of the outer peripheral member can be displaced relative to the outer peripheral surface of the rotor body.

[0021] Here, when the outer peripheral member extends to the vicinity of the outer periphery on both side surfaces of the rotor main body, the portions of the outer peripheral member other than the outer peripheral portions may be portions that cover the vicinity of the outer periphery on both side surfaces of the rotor main body. Also, when the contact portion is a central portion of the outer peripheral portion of the outer peripheral member in the direction of the rotation axis of the at least one rotor, the portions of the outer peripheral portion of the outer peripheral member other than the contact portion may be lateral portions of the outer peripheral portion of the outer peripheral member located on both sides of the contact portion in the direction of the rotation axis of the at least one rotor.

[0022] In addition, a rotor according to a second aspect of the present invention is a rotor for a ball launching device that sandwiches a ball between multiple rotors and launches the ball using the rotational force of the multiple rotors, and has a rotor main body supported on the main body of the ball launching device via a rotating shaft member, and an outer peripheral member formed of an elastic body and attached to the rotor main body so as to cover the outer peripheral surface of the rotor main body, wherein the outer peripheral portion, which is the portion of the outer peripheral member that covers the outer peripheral surface of the rotor main body, is displaceable relative to the outer peripheral surface of the rotor main body, and a non-contact portion that is not in contact with the inner peripheral surface of the outer peripheral member is formed on at least a part of the outer peripheral surface of the rotor main body. [Effects of the Invention]

[0023] According to the present invention, in a ball launching device that launches balls using the rotational force of multiple rotors, it is possible to suppress wear of the balls caused by the rotors. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a front view of the ball launching device. [Figure 2] FIG. 2 is a side view of the ball launching device. [Figure 3] FIG. 3 is a side view of the rotor support portion. [Figure 4] FIG. 4 is a diagram for explaining the configuration of the rotor mounting portion of the rotor support portion. [Figure 5] Figure 5 is a diagram for explaining the configuration of the rotor. Figure 5(a) is a side view of the rotor as viewed from the right side. Figure 5(b) is a cross-sectional view of the rotor in the direction of its rotation axis. [Figure 6] FIG. 6 is a diagram for explaining the configuration of the attachment portion of the outer peripheral member to the rotor body. [Figure 7] FIG. 7 is a front view of the rotor body showing the appearance of the rotor body. [Figure 8]FIG. 8 is a diagram showing the rotor and the ball when the ball is launched by the ball launching device. [Figure 9] FIG. 9 is a diagram illustrating the configuration of a rotor according to a first modified example. [Figure 10] FIG. 10 is a diagram illustrating the configuration of a rotor according to a third modified example. [Figure 11] FIG. 11 is a diagram illustrating the configuration of a rotor according to a fourth modified example. [Figure 12] FIG. 12 is a diagram illustrating the configuration of a rotor according to the fifth modified example. [Figure 13] FIG. 13 is a diagram showing an example of scratches on the surface of the ball caused by rubbing of the rotor. DETAILED DESCRIPTION OF THE INVENTION

[0025] Specific embodiments of the present invention will be described below with reference to the drawings. The dimensions, materials, shapes, and relative positions of the components described in the present embodiments are not intended to limit the technical scope of the present invention unless otherwise specified.

[0026] <Embodiment> [Overall configuration] The schematic configuration of the ball launching device according to this embodiment will be described with reference to Figs. 1 and 2. Figs. 1 and 2 are diagrams showing an example of the schematic configuration of the ball launching device according to this embodiment. Fig. 1 is a front view of the ball launching device 1. In Fig. 1, the direction perpendicular to the up-down direction is the left-right direction. In the following description, the left side of Fig. 1 is the left direction, and the right side of Fig. 1 is the right direction. Fig. 2 shows the ball launching device 1 as viewed from the right side. 2 is a side view of the ball launching device 1. In the following description, the left side of FIG. 2 is the front, and the right side of FIG. 2 is the rear. In addition, in FIGS. 1 and 2, a circle V represents a ball to be launched by the ball launching device 1.

[0027] The ball launching device 1 includes a main body 2 and two rotors 3. The rotor 3 has a substantially cylindrical shape with a rotation axis as its central axis. The two rotors 3 are attached to the main body 2 so that their rotation axes (central axes) are substantially parallel to each other. The two rotors 3 are also arranged side by side in the vertical direction with a predetermined distance between their outer circumferential surfaces. In the ball launching device 1, a ball V to be launched is sent from behind between the two rotors 3, which are rotating at high speed. The ball V is then sandwiched between the two rotors 3, and the rotational force of the two rotors 3 causes the ball V to be launched forward.

[0028] 1 and 2, the distance between the outer circumferential surfaces of the two rotors 3 of the ball launching device 1 is smaller than the outer diameter of the ball V. Therefore, the ball V is sandwiched between the two rotors 3 in a compressed state. For example, the distance T between the outer circumferential surfaces of the two rotors 3 (the distance at the narrowest point between the outer circumferential surfaces of the two rotors 3) may be set as follows: T=K×D1 D1: Outer diameter of ball V K: Coefficient (0.5 to 0.99)

[0029] The main body 2 of the ball launching device 1 includes a base 21, a rotor support part 22, and a rotor cover 23. An attachment part 211 for attaching the rotor support part 22 is provided at the upper end of the base 21. The rotor support part 22 has a support shaft 221, a support plate 222, and a support frame 223. A rotor cover 23 is provided for each of the two rotors 3.

[0030] A support shaft 221 of the rotor support part 22 is attached to the mounting part 211 of the base 21. The support shaft 221 is attached with a left portion of the support shaft 221 extending in the left-right direction inserted into the mounting part 211. In the rotor support part 22, the right end of the support shaft 221 is connected to the left side surface of a support plate 222, and the right side surface of the support plate 222 is connected to the support frame 223.

[0031] The support frame 223 of the rotor support part 22 is a frame assembled in a substantially rectangular shape with the vertical direction as the longitudinal direction. A rotor 3 is attached to each of the upper and lower ends of the support frame 223. The two rotors 3 are disposed on the right side of the support frame 223. Two motors 4 for driving and rotating each rotor 3 are attached to the left side of the support frame 223. In the following description, when the two rotors 3 are to be distinguished from one another, the rotor 3 attached to the upper end of the support frame 223 will be referred to as the first rotor 3a, and the rotor 3 attached to the lower end of the support frame 223 will be referred to as the second rotor 3b.

[0032] A rotor cover 23 is attached to the support frame 223 to cover each rotor 3. The rotor cover 23 is provided at the upper end of the support frame 223 so as to cover the first rotor 3a except for the lower portion thereof. The rotor cover 23 is provided at the lower end of the support frame 223 so as to cover the second rotor 3b except for the upper portion thereof.

[0033] In the ball launching device 1, the rotation speed of each rotor 3 can be adjusted by controlling the output of each motor 4 with a control device (not shown). By adjusting the rotation speed of each rotor 3, the launch speed and rotation state of the ball V can be changed. The rotation speeds of the two rotors 3 may be controlled independently.

[0034] The ball launching device 1 may also be provided with a ball guide frame for sending the ball V between the two rotors 3. The rotor support part 22 may also be attached to the base 21 so that its height position and angle can be changed. By changing the height position and angle of the rotor support part 22, the height of the launch position and the launch angle of the ball V can be changed.

[0035] It is also possible to adopt a configuration including three or more rotors in the ball launching device 1. In this case, the three or more rotors are arranged at a predetermined distance from each other, and the ball V is sandwiched between the three or more rotors.

[0036] The ball launching device 1 can be used, for example, as a baseball pitching machine, a tennis ball serving machine, a volleyball serving machine, or a soccer machine. The shape of the ball to be launched by the ball launching device 1 is not limited to a spherical shape with a circular cross section like ball V. For example, a ball with an oval cross section may also be launched.

[0037] [Configuration of rotor support part] Next, a more detailed configuration of the rotor support part 22 will be described with reference to Figs. 3 and 4. Fig. 3 is a side view of the rotor support part 22 when viewed from the right side. Fig. 4 is a diagram for explaining the configuration of the attachment part of the rotor 3 in the rotor support part 22. In Fig. 4, the vicinity of the attachment part of the rotor 3 in the rotor support part 22 is shown as a cross-sectional view of the cross-section indicated by AA in Fig. 3. For convenience, Figs. 3 and 4 show the state without the rotor cover 23. Also, in Figs. 3 and 4, a circle V represents a ball to be launched by the ball launching device 1.

[0038] A motor 4 is attached from the left side to each of the upper and lower ends of the support frame 223. A rotor attachment portion 225 is provided at each of the upper and lower ends of the support frame 223 at a position facing the motor 4. A rotor 3 is attached to each rotor attachment portion 225. The rotor 3 is attached to the rotor attachment portion 225 via a rotating shaft member 33. One end 331 of the rotating shaft member 33 is connected to the rotor body 31 of the rotor 3. The rotor 3 rotates around the central axis of the rotating shaft member 33. The detailed configuration of the rotor 3 will be described later.

[0039] The other end 332 of the rotating shaft member 33 of the rotor 3 is connected to the drive shaft 41 of the motor 4 provided at the opposite position via a coupling portion 42. As a result, the driving force of the motor 4 is transmitted from the drive shaft 41 via the coupling portion 42 to the rotating shaft member 33. In addition, the rotating shaft member 33 is rotatably supported by the rotor mounting portion 225 via a bearing portion 226. As a result, the rotor main body 31 of the rotor 3 is rotatably supported by the rotor support portion 22 via the rotating shaft member 33.

[0040] [Rotor configuration] Next, the detailed configuration of the rotor 3 will be described with reference to Figs. 5, 6, and 7. Fig. 5 is a diagram for explaining the configuration of the rotor 3. Fig. 5(a) is a side view of the rotor 3 when viewed from the right side. Fig. 5(b) is a cross-sectional view of the rotor 3 in the rotational axis direction. Fig. 5(b) is a cross-sectional view of the cross section indicated by BB in Fig. 5(a). Fig. 6 is a diagram for explaining the configuration of the attachment portion of the outer peripheral member 32 to the rotor main body 31 in the rotor 3. Fig. 6 shows the attachment portion of the outer peripheral member 32 to the rotor main body 31 in the rotor 3 as a cross-sectional view in the rotational axis direction. Fig. 7 shows the attachment portion of the rotor 3 in the rotational axis direction. FIG. 2 is a front view of the rotor body 31 showing the appearance of the body 31.

[0041] The rotor 3 has a rotor body 31 and an outer peripheral member 32. The rotor body 31 is a member having a substantially cylindrical shape. The rotor body 31 may be formed of a metal such as aluminum or iron. The rotor body 31 may also be formed of a resin to reduce its weight. The outer peripheral member 32 is a member that covers the outer peripheral surface 31A of the rotor body 31. The outer peripheral member 32 has a cylindrical shape and is formed of an elastic body.

[0042] The outer peripheral member 32 may be formed of rubber such as natural rubber, nitrile rubber, urethane rubber, silicone rubber, fluororubber, isoprene rubber, styrene rubber, or butadiene rubber. Furthermore, when the outer peripheral member 32 is formed of cylindrical rubber, its thickness may be 0.5 to 3.0 mm. More preferably, the thickness of the cylindrical rubber may be 1.0 to 2.0 mm. Furthermore, when the outer peripheral member 32 is formed of cylindrical natural rubber, the durometer hardness (Type A) of the natural rubber may be 10 to 50. More preferably, the durometer hardness (Type A) of the natural rubber may be 20 to 40.

[0043] The outer peripheral member 32 is attached to the rotor body 31 so as to cover the outer peripheral surface 31A of the rotor body 31. Therefore, in the ball launching device 1, the outer peripheral surface 32A of the outer peripheral part 321 of the outer peripheral member 32 comes into contact with the ball V sandwiched between the two rotors 3.

[0044] More specifically, as shown in FIG. 5(b), the rotor body 31 has a cylindrical member 311, a first side surface member 312, and a second side surface member 313. The cylindrical member 311 is a cylindrical member that forms the outer peripheral surface 31A of the rotor body 31. In other words, the outer peripheral wall surface of the cylindrical member 311 forms the outer peripheral surface 31A of the rotor body 31. Furthermore, the inner peripheral wall surface of the cylindrical member 311 forms the inner peripheral surface 31C of the rotor body 31. The first side surface member 312 is attached to the right end of the cylindrical member 311, and the second side surface member 313 is attached to the left end of the cylindrical member 311. The first side surface member 312 and the second side surface member 313 are fastened to each end of the cylindrical member 311 by a plurality of screws 314 arranged circumferentially.

[0045] Here, the first side surface member 312 has a disk shape and is attached to the right end of the cylindrical member 311 so as to cover the entire right opening of the cylindrical member 311. Also, a mounting hole 312A for mounting one end of the rotating shaft member 33 of the rotor 3 is formed in the center of the first side surface member 312. One end of the rotating shaft member 33 is mounted in the mounting hole 312A of the first side surface member 312 from the left side (i.e., the inner side of the rotor main body 31).

[0046] On the other hand, the second side surface member 313 has a ring shape. Therefore, the second side surface member 313 is attached to the left end of the cylindrical member 311 so as to cover only the portion of the left opening of the cylindrical member 311 near the inner circumferential surface of the cylindrical member 311. As a result, an opening 31B is formed on the left side surface of the rotor main body 31. Then, as shown in FIG. 4 , when the rotor 3 is attached to the rotor attachment portion 225 of the rotor support part 22, the rotor attachment portion 225 protrudes from the opening 31B of the rotor main body 31 into the internal space of the rotor 3. Then, in the internal space of the rotor 3, the rotating shaft member 33 is supported by the bearing portion 226.

[0047] Furthermore, in the rotor 3, the width of the outer peripheral member 32 (the width in the rotational axis direction of the rotor 3) is greater than the width of the rotor main body 31. Therefore, in the outer peripheral member 32, end portions 322 located on both sides of the outer peripheral portion 321, which is the portion that covers the outer peripheral surface 31A of the rotor main body 31, extend to the vicinity of the outer periphery on both sides of the rotor main body 31. Then, on both side surfaces of the rotor main body 31, the end portions 322 on both sides of the outer peripheral member 32 are fixed to the rotor main body 31 using fixing ring members 34, 35.

[0048] Here, a detailed description will be given of how the outer peripheral member 32 is attached to the rotor body 31 of the rotor 3. Note that Fig. 6 shows the attachment portion of the outer peripheral member 32 on the right side surface side (first side surface member 312 side) of the rotor 3.

[0049] In the first side surface member 312 of the rotor body 31, a step portion 3121 is formed around the entire circumference in a portion near the outer periphery connected to the cylindrical member 311. The step portion 3121 is formed by recessing the portion near the outer periphery of the first side surface member 312 toward the inside of the rotor 3 so that it conforms to the inner circumferential surface of the cylindrical member 311. Also, as shown in FIG. 6, a portion of the wall surface of the step portion 3121 is tapered. Hereinafter, the tapered portion of the wall surface of the step portion 3121 will be referred to as tapered portion 3121a. The wall surface of tapered portion 3121a of the step portion 3121 is inclined in a direction such that the diameter of the inner circumferential circle formed by the wall surface gradually decreases from the outside to the inside of the rotor 3 (from the right side to the left side in FIG. 6).

[0050] The fixing ring member 34 is fitted into the stepped portion 3121 of the first side surface member 312 with the right end portion 322 of the outer peripheral member 32 sandwiched therebetween. More specifically, as shown in FIG. 6, the outer peripheral surface 341 of the fixing ring member 34 is tapered, and the inclination corresponds to the inclination of the tapered portion 3121a of the stepped portion 3121 of the first side surface member 312. In other words, the outer peripheral surface 341 of the fixing ring member 34 is inclined in a direction such that the outer diameter of the fixing ring member 34 gradually decreases from the outside to the inside of the rotor 3 (from right to left in FIG. 6). The fixing ring member 34 is then fastened to the first side surface member 312 with screws 36 with the right end portion 322 of the outer peripheral member 32 sandwiched between the tapered portion 3121a of the stepped portion 3121 of the first side surface member 312 and the outer peripheral surface 341 of the fixing ring member 34. As shown in FIG. 5(a), the fixing ring member 34 is screwed to the first side surface member 312 by a plurality of screws 36 arranged on the circumference.

[0051] Similarly to the first side surface member 312, the second side surface member 313 of the rotor body 31 also has a step portion 3131 formed around the entire circumference in the vicinity of the outer periphery connected to the cylindrical member 311. The step portion 3131 is formed by recessing the portion of the second side surface member 313 in the vicinity of the outer periphery toward the inside of the rotor 3 so as to fit along the inner periphery of the cylindrical member 311. The step portion 3131 of the second side surface member 313 also has a tapered portion formed therein similar to the tapered portion 3121a of the step portion 3121 of the first side surface member 312.

[0052] Furthermore, a fixing ring member 35 is fitted into the stepped portion 3131 of the second side surface member 313 in a state in which the left end portion 322 of the outer peripheral member 32 is sandwiched therebetween. Like the fixing ring member 34, the outer peripheral surface of the fixing ring member 35 is tapered, and the inclination of the tapered portion corresponds to the inclination of the tapered portion of the stepped portion 3131 of the second side surface member 313. The fixing ring member 35 is then screwed to the second side surface member 313 with screws 37, with the left end portion 322 of the outer peripheral member 32 sandwiched between the tapered portion of the stepped portion 3131 of the second side surface member 313 and the outer peripheral surface of the fixing ring member 35. The fixing ring member 35 is screwed to the second side surface member 313 with a plurality of screws 37 arranged circumferentially.

[0053] As described above, in the rotor 3, both end portions 322 of the outer peripheral member 32 are fixed to the rotor main body 31. On the other hand, as shown in FIG. 5(b), the cross section of the outer peripheral surface 31A of the rotor main body 31 in the direction of the rotation axis of the rotor 3 is substantially linear. The inner peripheral surface 32B of the outer peripheral portion 321 of the outer peripheral member 32 is in contact with the outer peripheral surface 31A of the rotor main body 31. However, the outer peripheral portion 321 of the outer peripheral member 32 is not fixed to the rotor main body 31. Therefore, the outer peripheral portion 321 of the outer peripheral member 32 is displaceable relative to the outer peripheral surface 31A of the rotor main body 31. In other words, in the ball launching device 1 according to this embodiment, the rotor 3 is provided with an elastic body. The outer peripheral member 32 is attached to the rotor body 31 so that an outer peripheral portion 321 of the outer peripheral member 32 formed by the outer peripheral portion 321 is displaceable relative to the outer peripheral surface 31A of the rotor body 31. Furthermore, the rotor 3 is configured so that the outer peripheral portion 321 of the outer peripheral member 32 can be separated from the outer peripheral surface 31A of the rotor body 31 by displacing the outer peripheral portion 321 of the outer peripheral member 32 relative to the outer peripheral surface 31A of the rotor body 31.

[0054] In the rotor 3, the method for fixing the both side end portions 322 of the outer peripheral member 32 to the rotor body 31 is not limited to the method using the fixing ring members 34, 35 as described above. For example, the both side end portions 322 of the outer peripheral member 32 may be directly screwed to the first side member 312 and the second side member 313 of the rotor body 31, respectively.

[0055] As shown in FIGS. 5(b) and 7, a plurality of through holes 311A ​​are formed in the cylindrical member 311 of the rotor body 31. The through holes 311A ​​penetrate from the outer peripheral surface 31A to the inner peripheral surface 31C of the rotor body 31 (cylindrical member 311). The through holes 311A ​​are arranged at approximately equal intervals in the circumferential direction on both the right and left sides of the outer peripheral surface 31A of the rotor body 31. That is, the plurality of through holes 311A ​​arranged at approximately equal intervals in the circumferential direction are arranged in two rows in the direction of the central axis of the rotor body 31. The cross-sectional shape of the through holes 311A ​​in a direction perpendicular to the central axis is approximately circular. The diameter of the through holes 311A ​​may be, for example, 0.1 mm to 20.0 mm. However, the cross-sectional shape of the through holes 311A ​​in a direction perpendicular to the central axis is not limited to a substantially circular shape and may be a polygonal shape such as a square. It should be noted that a through-hole having a substantially circular cross-sectional shape is easier to process than a through-hole having a polygonal cross-sectional shape. Furthermore, the through-hole 311A ​​may be formed in a slit shape.

[0056] [Actions and Effects] In the ball launching device 1, when the rotor 3 is rotating without the ball V being sandwiched between the two rotors 3 (i.e., without the ball V contacting the outer circumferential surface 32A of the outer circumferential member 32 of the rotor 3), the rotor main body 31 and the outer circumferential member 32 rotate integrally. In other words, the outer circumferential portion 321 of the outer circumferential member 32 and the rotor main body 31 rotate at the same rotational speed. When the ball V is sent between the two rotors 3 rotating at high speed, the outer circumferential surface 32A of the outer circumferential portion 321 of the outer circumferential member 32 of the rotor 3 comes into contact with the ball V. This generates friction between the outer circumferential surface 32A of the outer circumferential portion 321 of the outer circumferential member 32 of the rotor 3 and the ball V.

[0057] Here, the coefficient of friction between the balls V and the outer peripheral surface 32A of the outer peripheral member 32 of the rotor 3 is greater than the coefficient of friction between the inner peripheral surface 32B of the outer peripheral member 32 and the outer peripheral surface 31A of the rotor main body 31. Furthermore, as described above, in the rotor 3, the outer peripheral portion 321 of the outer peripheral member 32 is displaceable with respect to the outer peripheral surface 31A of the rotor main body 31. Therefore, when the balls V come into contact with the outer peripheral surface 32A of the outer peripheral portion 321 of the outer peripheral member 32 while the rotor 3 is rotating at high speed and friction occurs therebetween, the outer peripheral portion 321 of the outer peripheral member 32 is temporarily displaced relative to the outer peripheral surface 31A of the rotor main body 31 in the direction opposite to the rotation direction of the rotor 3.

[0058] Furthermore, a plurality of through holes 311A ​​are provided in the outer peripheral surface 31A of the rotor body 31. At the openings of these through holes 311A ​​on the outer peripheral surface 31A side, the outer peripheral surface 31A is not present, and therefore the rotor body 31 does not come into contact with the inner peripheral surface 32B of the outer peripheral member 32. In other words, the rotor 3 has a plurality of non-contact portions where the outer peripheral surface 31A of the rotor body 31 does not come into contact with the inner peripheral surface 32B of the outer peripheral member 32. The formation of such non-contact portions makes it easier for the outer peripheral portion 321 of the outer peripheral member 32 to displace relative to the outer peripheral surface 31A of the rotor body 31 when friction occurs between the balls V and the outer peripheral surface 32A of the outer peripheral portion 321 of the outer peripheral member 32.

[0059] Furthermore, in the rotor body 31, each through-hole 311A ​​penetrates from the outer peripheral surface 31A to the inner peripheral surface 31C. Therefore, when the rotor 3 rotates, air is supplied from the inside of the rotor body 31 through each through-hole 311A ​​between the outer peripheral surface 31A of the rotor body 31 and the inner peripheral surface 32B of the outer peripheral member 32. As a result, an air layer is formed between the outer peripheral surface 31A of the rotor body 31 and the inner peripheral surface 32B of the outer peripheral member 32. When such an air layer is formed, when friction occurs between the ball V and the outer peripheral surface 32A of the outer peripheral member 32, the outer peripheral portion 321 of the outer peripheral member 32 is more likely to displace relative to the outer peripheral surface 31A of the rotor body 31. Therefore, rubbing of the surface of the ball V by the outer peripheral member 32 can be further suppressed.

[0060] The arrangement of the multiple through holes 311A ​​in the rotor body 31 is not limited to the arrangement shown in Figures 5(b) and 7. The multiple through holes 311A ​​may be provided near the center of the outer peripheral surface 31A of the rotor body 31 in the direction of the central axis of the rotor body 31. The multiple through holes 311A ​​do not have to be arranged in a row on the outer peripheral surface 31A of the rotor body 31. Furthermore, the rotor body 31 does not necessarily have to have multiple through holes 311A, and the above-mentioned effects can be obtained even if there is only one through hole 311A. 5(b) and 7, by providing a plurality of through holes 311A ​​in the outer peripheral surface 31A of the rotor body 31 at approximately equal intervals in the circumferential direction, when the rotor 3 rotates, air is supplied from the inside of the rotor body 31 through the plurality of through holes 311A, thereby forming an approximately uniform air layer in the circumferential direction between the outer peripheral surface 31A of the rotor body 31 and the inner peripheral surface 32B of the outer peripheral member 32. Therefore, in order to suppress rubbing of the surface of the ball V by the outer peripheral member 32, such an arrangement of the plurality of through holes 311A ​​in the rotor body 31 is more suitable.

[0061] FIG. 8 is a diagram showing the state of the rotor 3 and the ball V when the ball V is launched by the ball launching device 1. FIGS. 8(a) to 8(c) show the state of the rotor 3 (first rotor 3a) and the ball V when the ball V is caught between two rotors 3 rotating at high speed. Note that in FIGS. 8(a) to 8(c), the arrows indicate the direction of rotation of the rotor 3. In FIG. 8, time progresses in the order of (a), (b), and (c). Therefore, in FIG. 8, the ball V moves from rear to front as time passes from (a) to (c).

[0062] When the ball V is sandwiched between the two rotors 3, friction occurs between the outer peripheral surface 32A of the outer peripheral portion 321 of the outer peripheral member 32 and the ball V, and the rotation speed of the contact portion of the outer peripheral portion 321 of the outer peripheral member 32 with the ball V decreases. As a result, the outer peripheral portion 321 of the outer peripheral member 32 is displaced relative to the outer peripheral surface 31A of the rotor main body 31 in the opposite direction to the rotation direction of the rotor 3. At this time, the amount of displacement of the outer peripheral portion 321 of the outer peripheral member 32 with respect to the outer peripheral surface 31A of the rotor main body 31 is greater in the vicinity of the contact portion of the outer peripheral portion 321 of the outer peripheral member 32 with the ball V.

[0063] Then, as the amount of displacement of the outer peripheral portion 321 of the outer peripheral member 32 relative to the outer peripheral surface 31A of the rotor main body 31 increases, a portion of the outer peripheral portion 321 separates from the outer peripheral surface 31A of the rotor main body 31. In FIGS. 8(a) to 8(c), the area surrounded by dashed lines indicates the portion of the outer peripheral portion 321 of the outer peripheral member 32 that has separated from the outer peripheral surface 31A of the rotor main body 31. As shown in FIGS. 8(a) to 8(c), the rear portion of the portion of the outer peripheral portion 321 of the outer peripheral member 32 that is in contact with the ball V in the rotation direction of the rotor 3 separates from the outer peripheral surface 31A of the rotor main body 31. Furthermore, as shown in FIGS. 8(a) to 8(c), when a portion of the outer peripheral portion 321 of the outer peripheral member 32 separates from the outer peripheral surface 31A of the rotor main body 31, the separated portion of the outer peripheral portion 321 bulges outward in the radial direction of the rotor 3.

[0064] As described above, when the outer peripheral portion 321 of the outer peripheral member 32 is displaced in the direction opposite to the rotation direction of the rotor 3 relative to the outer peripheral surface 31A of the rotor body 31 while in contact with the ball V, the outer peripheral member 32 of the rotor 3 is less likely to slip on the surface of the ball V. Therefore, the outer peripheral member 32 of the rotor 3 is less likely to rub against the surface of the ball V. Therefore, wear of the ball V by the rotor 3 can be suppressed.

[0065] Furthermore, by separating a part of the outer peripheral portion 321 of the outer peripheral member 32 from the outer peripheral surface 31A of the rotor body 31, the outer peripheral portion 321 of the outer peripheral member 32 can be displaced relatively more with respect to the outer peripheral surface 31A of the rotor body 31. Therefore, rubbing of the surface of the ball V by the outer peripheral member 32 can be further suppressed.

[0066] Even if the outer peripheral portion 321 of the outer peripheral member 32 is displaced relative to the outer peripheral surface 31A of the rotor main body 31 in the direction opposite to the rotation direction of the rotor 3, the rotational force of the rotor 3 increases the forward moving speed of the ball V. Then, the ball V is launched from the ball launching device 1 at a speed corresponding to the rotation speed of the rotor 3. Furthermore, when the ball V is launched from the ball launching device 1 and moves away from the outer peripheral portion 321 of the outer peripheral member 32 in the rotor 3, the displacement of the outer peripheral portion 321 of the outer peripheral member 32 relative to the outer peripheral surface 31A of the rotor main body 31 is eliminated.

[0067] In the ball launching device 1, it is not necessary for both of the two rotors 3 to have the above-described configuration. In other words, only one of the first rotor 3a and the second rotor 3b may have the above-described configuration. In this case, the other of the first rotor 3a and the second rotor 3b may have a configuration in which, for example, an outer peripheral member 32 is bonded to the entire outer peripheral surface 31A of the rotor body 31. Even if only one of the first rotor 3a and the second rotor 3b has the above-described configuration, it is possible to suppress wear of the ball V caused by the rotor 3. Furthermore, even if the ball launching device 1 has three or more rotors 3, as long as at least one rotor 3 has the above-described configuration, it is possible to obtain the effect of suppressing wear of the ball V caused by the rotor 3.

[0068] [Variation 1] Next, a first modified example of the rotor of the ball launching device according to this embodiment will be described with reference to Fig. 9. Fig. 9 is a diagram for explaining the configuration of the rotor 3 according to the first modified example. Fig. 9 shows a front view of the rotor body 31 showing the appearance of the rotor body 31. In this modified example, the configuration of the rotor body 31 is different from that of the above-described embodiment.

[0069] In this modification, a plurality of recesses 311B are provided on the outer peripheral surface 31A of the rotor main body 31 (cylindrical member 311) instead of the plurality of through holes 311A ​​according to the above embodiment. The plurality of recesses 311B are provided over the entire surface of the outer peripheral surface 31A of the rotor main body 31 (cylindrical member 311). In other words, the outer peripheral surface 31A of the rotor main body 31 has a so-called dimple structure.

[0070] According to the configuration of this modified example, the outer peripheral surface 31A of the rotor body 31 does not come into contact with the inner peripheral surface 32B of the outer peripheral member 32 at the openings of the multiple recesses 311B. In other words, even with the configuration of this modified example, multiple non-contact portions are formed in the rotor 3 where the outer peripheral surface 31A of the rotor body 31 does not come into contact with the inner peripheral surface 32B of the outer peripheral member 32. Furthermore, the formation of such non-contact portions makes it easier for the outer peripheral portion 321 of the outer peripheral member 32 to displace relative to the outer peripheral surface 31A of the rotor body 31 when friction occurs between the balls V and the outer peripheral surface 32A of the outer peripheral portion 321 of the outer peripheral member 32. Therefore, even with the configuration of this modified example, it is possible to further suppress rubbing of the surface of the balls V by the outer peripheral member 32. Note that in this modified example, the multiple recesses 311B do not necessarily come into contact with the outer peripheral surface 31A of the rotor body 31 (the cylindrical member 311). The recess 311B does not need to be provided over the entire surface of the outer circumferential surface 31A, and may be provided only in a partial region of the outer circumferential surface 31A. The cross-sectional shape of the recess 311B in a direction perpendicular to the central axis is not limited to a substantially circular shape, and may be a polygonal shape such as a square. The recess 311B may be provided in the outer circumferential surface 31A of the rotor body 31 (cylindrical member 311) in the form of a groove (for example, a groove that goes around the outer periphery of the cylindrical member 311).

[0071] [Variation 2] Next, a second modified example of the rotor of the ball launching device according to this embodiment will be described. In this modified example, instead of the multiple through holes 311A ​​formed in the outer peripheral surface 31A of the rotor main body 31 (cylindrical member 311) according to the above-described embodiment, multiple through holes are provided in the outer peripheral portion 321 of the outer peripheral member 32. Here, the multiple through holes may be provided over the entire outer peripheral portion 321, or may be provided only in a partial region of the outer peripheral portion 321. Furthermore, the cross-sectional shape of the through holes in a direction perpendicular to the central axis may be substantially circular, or may be polygonal, such as rectangular.

[0072] According to the configuration of this modification, the inner circumferential surface 32B of the plurality of through holes formed in the outer circumferential portion 321 of the outer circumferential member 32 is not present at the openings on the inner circumferential surface 32B side of the plurality of through holes formed in the outer circumferential portion 321 of the outer circumferential member 32, and therefore the outer circumferential surface 31A of the rotor main body 31 and the outer circumferential portion 321 of the outer circumferential member 32 do not come into contact with each other. In other words, even with the configuration of this modification, the rotor 3 has a plurality of non-contact portions where the outer circumferential surface 31A of the rotor main body 31 and the inner circumferential surface 32B of the outer circumferential member 32 do not come into contact with each other. Furthermore, when the rotor 3 rotates, air is supplied between the outer circumferential surface 31A of the rotor main body 31 and the inner circumferential surface 32B of the outer circumferential member 32 through the through holes formed in the outer circumferential portion 321 of the outer circumferential member 32. As a result, an air layer is formed between the outer circumferential surface 31A of the rotor main body 31 and the inner circumferential surface 32B of the outer circumferential portion 321 of the outer circumferential member 32.

[0073] Therefore, even with the configuration of this modified example, when friction occurs between the balls V and the outer peripheral surface 32A of the outer peripheral portion 321 of the outer peripheral member 32, the outer peripheral portion 321 of the outer peripheral member 32 is more likely to be displaced relative to the outer peripheral surface 31A of the rotor body 31. Therefore, rubbing of the surface of the balls V by the outer peripheral member 32 can be further suppressed.

[0074] In this modification, recesses may be provided on the inner circumferential surface 32B of the outer circumferential portion 321 of the outer circumferential member 32 instead of through holes. That is, the inner circumferential surface 32B of the outer circumferential portion 321 of the outer circumferential member 32 may have a so-called dimple structure. In this case, the recesses may have a substantially circular cross-sectional shape in a direction perpendicular to the central axis, or may have a polygonal shape such as a quadrangle. Furthermore, the recesses may be provided in the inner circumferential surface 32B of the outer circumferential portion 321 of the outer circumferential member 32 in the form of grooves (for example, grooves that surround the inner circumference of the outer circumferential portion 321). Furthermore, in this modification, the outer circumferential member 32 may be formed of a mesh-like member. These configurations also form non-contact portions in the rotor 3 where the outer circumferential surface 31A of the rotor body 31 and the inner circumferential surface 32B of the outer circumferential member 32 are not in contact with each other. Therefore, when friction occurs between the balls V and the outer peripheral surface 32A of the outer peripheral portion 321 of the outer peripheral member 32, the outer peripheral portion 321 of the outer peripheral member 32 is easily displaced relative to the outer peripheral surface 31A of the rotor body 31.

[0075] [Variation 3] Next, a third modified example of the rotor of the ball launching device according to this embodiment will be described with reference to Fig. 10. Fig. 10 is a diagram for explaining the configuration of the rotor 3 according to the third modified example. Fig. 10 shows a part of a cross-sectional view of the rotor 3 in the direction of the rotation axis.

[0076] In the rotor 3 according to this modification, the outer peripheral surface 31A of the rotor body 31 is also covered with the outer peripheral member 32. The rotor body 31 has a cylindrical member 311, a first side surface member 312, and a second side surface member 313. Both end portions 322 of the outer peripheral member 32 are fixed to the rotor body 31 using fixing ring members 34, 35. However, in this modified example, the shape of the outer peripheral surface 31A of the rotor body 31 is different from that of the above-described embodiment.

[0077] In the rotor 3 according to this modification, the outer peripheral wall surface of the cylindrical member 311 of the rotor body 31 has a constricted shape in the central portion in the direction of the rotational axis of the rotor 3 (the left-right direction in FIG. 10). As a result, as shown in FIG. 10, the cross-sectional shape of the outer peripheral surface 31A of the rotor body 31 in the direction of the rotational axis of the rotor 3 has a V-shape with the central portion recessed toward the inside of the rotor 3. Here, the inclination angle of the V-shaped portion of the outer peripheral surface 31A of the rotor body 31 may be, for example, 3° to 10°. However, the inclination angle of the V-shaped portion of the outer peripheral surface 31A of the rotor body 31 is not limited to 3° to 10°.

[0078] Meanwhile, in the rotor 3 according to this modification, the cross-sectional shape of the outer peripheral portion 321 of the outer peripheral member 32 in the rotational axis direction of the rotor 3 is substantially linear, as in the above-described embodiment. Therefore, in the rotor 3 according to this modification, a space S is formed between the outer peripheral surface 31A of the rotor main body 31 and the inner peripheral surface 32B of the outer peripheral portion 321 of the outer peripheral member 32. As a result, a non-contact portion, where the outer peripheral surface 31A of the rotor main body 31 and the inner peripheral surface 32B of the outer peripheral member 32 do not contact each other, is formed over a wide area of ​​the outer peripheral surface 31A of the rotor main body 31. The formation of such a non-contact portion makes it easier for the outer peripheral portion 321 of the outer peripheral member 32 to displace relative to the outer peripheral surface 31A of the rotor main body 31 when friction occurs between the balls V and the outer peripheral surface 32A of the outer peripheral portion 321 of the outer peripheral member 32. Therefore, the configuration according to this modification also further suppresses rubbing of the surfaces of the balls V by the outer peripheral member 32.

[0079] The size of the space S formed between the outer peripheral surface 31A of the rotor body 31 and the inner peripheral surface 32B of the outer peripheral portion 321 of the outer peripheral member 32 can be adjusted by the inclination angle of the V-shaped portion of the outer peripheral surface 31A of the rotor body 31. The size of the space S may also be determined depending on the material, shape, etc. of the outer peripheral member 32. In this modification, the cross-sectional shape of the outer peripheral surface 31A of the rotor body 31 in the direction of the rotation axis of the rotor 3 is not limited to a V-shape. For example, the cross-sectional shape of the outer peripheral surface 31A of the rotor body 31 in the direction of the rotation axis of the rotor 3 may have a concave shape with a central portion recessed toward the inside of the rotor 3. The concave shape may be, for example, a U-shape. Even in this case, a space is formed in a portion between the outer peripheral surface 31A of the rotor body 31 and the inner peripheral surface 32B of the outer peripheral portion 321 of the outer peripheral member 32. As a result, a non-contact portion where the outer peripheral surface 31A of the rotor body 31 and the inner peripheral surface 32B of the outer peripheral member 32 are not in contact with each other is formed over a wide area of ​​the outer peripheral surface 31A of the rotor body 31.

[0080] [Variation 4] Next, a fourth modified example of the rotor of the ball launching device according to this embodiment will be described with reference to Fig. 11. Fig. 11 is a diagram for explaining the configuration of the rotor 3 according to the fourth modified example. Fig. 11 shows a cross-sectional view of the rotor 3 in the vicinity of the outer circumferential surface 31A of the rotor main body 31 in the rotation axis direction.

[0081] In the rotor 3 according to this modification, the outer peripheral surface 31A of the rotor body 31 is also covered with the outer peripheral member 32. The cross-sectional shape of the outer peripheral surface 31A of the rotor body 31 in the direction of the rotation axis of the rotor 3 is substantially linear, as in the above-described embodiment. However, in this modification, the shape of the outer peripheral portion 321 of the outer peripheral member 32 is different from that in the above-described embodiment.

[0082] As shown in Fig. 11, in the rotor 3 according to this modification, the cross-sectional shape of the outer peripheral part 321 of the outer peripheral member 32 in the direction of the rotation axis of the rotor 3 has a V-shape in which the central part in the direction of the rotation axis of the rotor 3 (the left-right direction in Fig. 11) is recessed toward the inside of the rotor 3. Here, the inclination angle of the V-shaped part of the outer peripheral part 321 of the outer peripheral member 32 may be, for example, 2°. In this modification, the cross-sectional shape of the outer peripheral surface 31A of the rotor body 31 in the rotational axis direction of the rotor 3 has a concave shape in which both end portions in the rotational axis direction of the rotor 3 protrude toward the outside of the rotor 3. Here, in the rotor body 31, the outer peripheral portions of the first side surface member 312 and the second side surface member 313 may protrude toward the outside of the rotor 3 beyond the outer peripheral surface 31A of the tubular member 311, thereby forming the concave cross-sectional shape. Also in this modification, both end portions 322 of the outer peripheral member 32 are fixed to the rotor body 31 on both side surfaces of the rotor body 31. In addition, in the outer peripheral portion 321 of the outer peripheral member 32, the inner peripheral surface 32B contacts the outer peripheral surface 31A of the rotor body 31 only at both end portions and the central portion in the rotational axis direction of the rotor 3, and the inner peripheral surface 32B is separated from the outer peripheral surface 31A of the rotor body 31 in other portions.

[0083] Therefore, even with the configuration according to this modification, a space S is formed between the outer peripheral surface 31A of the rotor body 31 and the inner peripheral surface 32B of the outer peripheral portion 321 of the outer peripheral member 32. As a result, a non-contact portion where the outer peripheral surface 31A of the rotor body 31 and the inner peripheral surface 32B of the outer peripheral member 32 are not in contact with each other is formed over a wide area of ​​the outer peripheral surface 31A of the rotor body 31. Therefore, it is possible to obtain the same effect as in the second modification described above.

[0084] In this modification, the cross-sectional shape of the outer peripheral portion 321 of the outer peripheral member 32 in the rotational axis direction of the rotor 3 is not limited to a V-shape. For example, the cross-sectional shape of the outer peripheral portion 321 of the outer peripheral member 32 in the rotational axis direction of the rotor 3 may have a concave shape with a central portion recessed toward the inside of the rotor 3. Even in this case, in the outer peripheral portion 321 of the outer peripheral member 32, the inner peripheral surface 32B contacts the outer peripheral surface 31A of the rotor main body 31 in a portion near the center in the rotational axis direction of the rotor 3, and the inner peripheral surface 32B is separated from the outer peripheral surface 31A of the rotor main body 31 in other portions. Therefore, a space is formed in part between the outer peripheral surface 31A of the rotor main body 31 and the inner peripheral surface 32B of the outer peripheral portion 321 of the outer peripheral member 32. As a result, a non-contact portion where the outer peripheral surface 31A of the rotor main body 31 and the inner peripheral surface 32B of the outer peripheral portion 321 of the outer peripheral member 32 do not contact each other is formed over a wide range of the outer peripheral surface 31A of the rotor main body 31.

[0085] Furthermore, in the ball launching device 1, it is not necessary for both of the two rotors 3 to have the same configuration. In other words, one of the first rotor 3a and the second rotor 3b may employ the configuration according to the embodiment described above, and the other may employ the configuration according to one of the modifications described above. Similarly, when the ball launching device 1 is equipped with three or more rotors 3, it is not necessary for all of the three or more rotors 3 to have the same configuration.

[0086] [Variation 5] Next, a fifth modified example of the rotor of the ball launching device according to this embodiment will be described with reference to Fig. 12. Fig. 12 is a diagram for explaining the configuration of the rotor 3 according to the fifth modified example. Fig. 12 is a diagram showing the outer circumferential surface of the rotor 3. In Fig. 12, a circle V represents a ball sandwiched between two rotors 3.

[0087] In the rotor 3 according to this modification, the outer peripheral surface 31A of the rotor body 31 is also covered with the outer peripheral member 32. However, in this modification, the method of attaching the outer peripheral member 32 to the rotor body 31 differs from that in the above-described embodiment.

[0088] In this modified example, the width of the outer peripheral member 32 (the width in the rotational axis direction of the rotor 3) is equal to the width of the rotor main body 31. Here, when a ball V is sandwiched between the two rotors 3, the outer peripheral surface 32A in the central portion of the outer peripheral part 321 of the outer peripheral member 32 comes into contact with the ball V. Therefore, in the central portion of the outer peripheral part 321 of the outer peripheral member 32, a contact portion 321a is formed where the outer peripheral surface 32A comes into contact with the ball V. On the other hand, in the outer peripheral part 321 of the outer peripheral member 32, in side portions 321b located on both sides of the contact portion 321a, the outer peripheral surface 32A comes into contact with the ball V. It should be noted that the width of the area on the outer peripheral surface 32A of the outer peripheral portion 321 of the outer peripheral member 32 that actually comes into contact with the ball V varies depending on the diameter of the ball V and the degree to which the ball V is compressed when sandwiched between the two rotors 3. Therefore, the width of the contact portion 321a on the outer peripheral portion 321 of the outer peripheral member 32 is determined taking these factors into consideration.

[0089] In this modification, the side portions 321b of the outer peripheral portion 321 of the outer peripheral member 32 are screwed to the outer peripheral surface 31A of the rotor main body 31 with screws 38. As shown in FIG. 12 , the side portions 321b of the outer peripheral portion 321 of the outer peripheral member 32 are screwed to the outer peripheral surface 31A of the rotor main body 31 with a plurality of screws 38 aligned along the outer periphery of the side portions 321b. The method of fixing the side portions 321b of the outer peripheral portion 321 of the outer peripheral member 32 to the outer peripheral surface 31A of the rotor main body 31 is not limited to this screw fixing. For example, the side portions 321b of the outer peripheral portion 321 of the outer peripheral member 32 may be fixed by being sandwiched between a ring-shaped fixing member having approximately the same width as the side portions 321b and the outer peripheral surface 31A of the rotor main body 31.

[0090] According to this, in the rotor 3, side portions 321b located on both sides of the contact portion 321a in the outer peripheral portion 321 of the outer peripheral member 32 are fixed to the rotor main body 31. However, the contact portion 321a of the outer peripheral portion 321 of the outer peripheral member 32 is not fixed to the rotor main body 31. Therefore, the contact portion 321a of the outer peripheral portion 321 of the outer peripheral member 32 is displaceable with respect to the outer peripheral surface 31A of the rotor main body 31.

[0091] When the rotor 3 is rotating at high speed and the ball V comes into contact with the outer peripheral surface 32A of the contact portion 321a of the outer peripheral part 321 of the outer peripheral member 32, friction occurs between the outer peripheral surface 32A of the contact portion 321a and the ball V. At this time, in the configuration according to this modified example, the contact portion 321a of the outer peripheral part 321 of the outer peripheral member 32 is displaced relative to the outer peripheral surface 31A of the rotor main body 31 in the direction opposite to the rotation direction of the rotor 3. Furthermore, when the amount of displacement of the contact portion 321a of the outer peripheral part 321 of the outer peripheral member 32 relative to the outer peripheral surface 31A of the rotor main body 31 increases, a part of the contact portion 321a separates from the outer peripheral surface 31A of the rotor main body 31.

[0092] Therefore, the configuration according to this modified example also makes it difficult for the outer peripheral member 32 of the rotor 3 to slip on the surface of the ball V. As a result, the outer peripheral member 32 of the rotor 3 is less likely to rub against the surface of the ball V. Therefore, wear of the ball V by the rotor 3 can be suppressed.

[0093] [Test results of launch test] The results of a launch test conducted using an example and a comparative example of a ball launching device are described below. In this launch test, a volleyball was launched using a ball launching device equipped with two rotors. After launch, the presence of scratches on the surface of the ball due to friction between the rotors was confirmed.

[0094] <Configuration of ball launching device> Rotor body: Metal rotor Rotor outer diameter: 220mm Rotor width: 160mm Distance between two rotors (minimum distance between outer surfaces): 155 mm The ball used Volleyball size 5 (Mikasa V300W) Ball diameter: approx. 210mm Ball air pressure: 0.031 MPaG

[0095] Configuration of the rotor according to the embodiment The cylindrical natural rubber outer periphery was fixed to both sides of the rotor body (metal rotor). The dimensions of the cylindrical natural rubber were 1 mm thick and 127 mm in inner diameter (circumferential length 400 mm). The outer peripheral surface of the rotor body and the outer peripheral portion of the outer peripheral member have a cross-sectional shape in the direction of the rotation axis of the rotor that is substantially linear. On the outer surface of the rotor body, through holes (diameter 4 mm) were arranged in three rows in the direction of the central axis of the rotor body, with eight holes formed in each row at approximately equal intervals in the circumferential direction.

[0096] <Configuration of a rotor according to a comparative example> A 10 mm thick urethane rubber was fixed to the outer surface of the rotor body (metal rotor).

[0097] The launch test was conducted multiple times by changing the rotor rotation speed (number of rotations, peripheral speed). After each launch, the ball's surface was visually inspected, and if scratches of 1 mm or larger were found, the ball was evaluated as having scratches. Figure 13 shows an example of scratches on the ball's surface caused by rotor friction.

[0098] Table 1: Test results of the examples TIFF2026045270000002.tif33153

[0099] Table 2: Test results for comparative examples TIFF2026045270000003.tif33153

[0100] As shown in Table 1 above, in the Examples, no scratches were observed on the surface of the ball in any of the shots. On the other hand, as shown in Table 2 above, in the Comparative Examples, scratches were observed on the surface of the ball in all shots except for No. 5.

[0101] [Natural rubber evaluation results] The results of the evaluation tests carried out on the natural rubber used as the outer peripheral member in the above examples will be described below. As the evaluation tests, a tensile test was carried out on a test piece of natural rubber to measure the elongation of the test piece.

[0102] Tensile test method The test specimens used were rectangular plate-shaped specimens with a thickness of 1 mm, length of 60 mm, and width of 20 mm. In the tensile test, the test specimen was gripped near both ends (17.5 mm from the end) with the gripping tools of a testing machine (Shimadzu Corporation Autograph) and pulled at a specified speed (60 mm / min). At this time, the part of the test specimen with a distance of 25 mm between the fixed points of the gripping tools was The amount of elongation was measured. The test specimen was fixed in place by wrapping it around a stainless steel round bar (diameter 6 mm) and gripping it together with the round bar. The tensile test was carried out in an indoor environment at a temperature of 25°C.

[0103] Table 3 below shows the measurement results when tensile tests were carried out at tensile loads of 8N and 12N. Table 3: Tensile test results TIFF2026045270000004.tif22170

[0104] According to the results of the above-mentioned launch test, it is believed that if an elastic body having an elongation of 42% at a tensile stress of 0.4 MPa or an elongation of 88% at a tensile stress of 0.6 MPa in the above-mentioned tensile test is used as the outer peripheral member of the rotor according to the present invention, it is possible to suppress wear of the ball due to friction with the rotor.

[0105] The elastic body used as the outer peripheral member of the rotor according to the present invention preferably has an elongation of 16 to 95% at a tensile stress of 0.4 MPa, or an elongation of 24 to 143% at a tensile stress of 0.6 MPa, in the above-mentioned tensile test. Furthermore, considering that the elastic body used as the outer peripheral member of the rotor will be used repeatedly, it is desirable that the magnitude of plastic strain in response to tensile stress be as small as possible. For example, it is preferable that the plastic strain of the elastic body be 3% or less when a tensile load is applied to the elastic body until it elongates by 200% and then the tensile load is released. [Explanation of symbols]

[0106] 1. Ball launcher 2. Main unit 21 Mounting stand 22 Rotor support 221...Support shaft 222··Support plate 223··Support frame 3. Rotor 3a First rotor 3b Second rotor 31 Rotor body 31A...Outer surface 31C...Inner surface 311 Cylindrical member 311A...Through hole 311B··Concave 32. Peripheral member 32A...Outer surface 32B...Inner surface 321··Outer periphery 322··End 33 Rotating shaft member 34, 35 Fixing ring member 4. Motor

Claims

1. A ball launching device that sandwiches a ball between multiple rotors and launches the ball by the rotational force of the multiple rotors, At least one rotor of the plurality of rotors is a rotor body supported on the body of the ball launching device via a rotary shaft member; an outer peripheral member formed of an elastic body and attached to the rotor body so as to cover the outer peripheral surface of the rotor body; In the at least one rotor, The outer peripheral member is attached to the rotor body such that the outer peripheral portion of the outer peripheral member, which covers the outer peripheral surface of the rotor body, is displaceable relative to the outer peripheral surface of the rotor body. a non-contact portion that is not in contact with the inner peripheral surface of the outer peripheral member is formed on at least a part of the outer peripheral surface of the rotor body; Ball launcher.

2. In the at least one rotor, The non-contact portion is formed by a through hole that penetrates from the outer peripheral surface to the inner peripheral surface of the rotor body.

2. The ball launching device of claim 1.

3. In the at least one rotor, A plurality of the through holes are provided on the outer peripheral surface of the rotor body at approximately equal intervals in the circumferential direction.

3. The ball launching device of claim 2.

4. In the at least one rotor, The non-contact portion is formed by a plurality of recesses provided on the outer circumferential surface of the rotor body.

2. The ball launching device of claim 1.

5. In the at least one rotor, The non-contact portion is formed such that the cross-sectional shape of the outer circumferential surface of the rotor body in the direction of the rotation axis of at least one rotor is V-shaped or concave, and the cross-sectional shape of the outer circumferential portion of the outer circumferential member in the direction of the rotation axis of at least one rotor is substantially straight.

2. The ball launching device of claim 1.

6. Claim 3 of 24-022 In the at least one rotor, The portion of the outer peripheral member other than the outer peripheral portion, or the portion of the outer peripheral portion of the outer peripheral member other than the contact portion where the outer peripheral surface contacts the ball, is fixed to the rotor body.

2. The ball launching device of claim 1.

7. Claim 4 of 24-022 The outer peripheral member extends to the vicinity of the outer periphery of both side surfaces of the rotor body, The portions of the outer peripheral member other than the outer peripheral portion are portions that cover the outer peripheral vicinity of both side surfaces of the rotor body.

7. The ball launching device of claim 6.

8. Claim 5 of 24-022 In the outer peripheral portion of the outer peripheral member, a central portion in a rotation axis direction of the at least one rotor is the contact portion, the portions of the outer peripheral portion of the outer peripheral member other than the contact portion are side portions of the outer peripheral portion of the outer peripheral member located on both sides of the contact portion in a direction of a rotation axis of the at least one rotor.

7. The ball launching device of claim 6.

9. A rotor of a ball launching device that sandwiches a ball between multiple rotors and launches the ball by the rotational force of the multiple rotors, a rotor body supported on the body of the ball launching device via a rotary shaft member; an outer peripheral member formed of an elastic body and attached to the rotor body so as to cover the outer peripheral surface of the rotor body; The outer peripheral member is attached to the rotor body such that the outer peripheral portion of the outer peripheral member, which covers the outer peripheral surface of the rotor body, is displaceable relative to the outer peripheral surface of the rotor body. a non-contact portion that is not in contact with the inner peripheral surface of the outer peripheral member is formed on at least a part of the outer peripheral surface of the rotor body; rotor.

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