Wheel arrangement

Abstract

In a wheel device, a first elastic body connects a middle member and a wheel rim to each other in such a manner that the middle member is movable with respect to the wheel rim along a first imaginary straight line orthogonal to an axis of the middle member. A second elastic body connects the middle member and a main body rotating portion to each other in such a manner that the middle member is movable with respect to the main body rotating portion along a second imaginary straight line orthogonal to the axis of the middle member and intersecting the first imaginary straight line. A damping structure portion has a counterweight that rotates in the same direction as a rotation direction of the main body rotating portion at a rotational speed that is 2 times a rotational speed of the main body rotating portion. When a direction along the second imaginary straight line coincides with a vertical direction, a position of a center of gravity of the counterweight becomes a position that is lower than a rotational center line of the counterweight.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a wheel device having a ring-shaped rim (Japanese: tire). BACKGROUND

[0002] In the past, in order to achieve low-flooring of a car body of a railway vehicle, a wheel device that houses a drive device inside a ring-shaped rim is known. In such a conventional wheel device, at the time of running of the railway vehicle, an impact force from a track is easily transmitted to the drive device via the rim. In particular, at the time of passing through a joint between two continuous tracks, at the time of generation of abnormal wear on an outer peripheral surface of the rim, or the like, the impact force received by the drive device housed inside the rim becomes large. Therefore, in the conventional wheel device, there is a concern that the drive device easily fails.

[0003] In the past, a wheel device in which, in order to suppress an impact force transmitted from a rim to a drive device, a circular ring-shaped intermediate member is provided between the drive device housed inside the rim and the rim, and the intermediate member is connected to the drive device and the rim by a plurality of spring elements has been proposed (for example, refer to Non-Patent Literature 1).

[0004] PRIOR ART DOCUMENTS

[0005] NON-PATENT LITERATURE

[0006] Non-Patent Literature 1: Japan Society of Mechanical Engineers Dynamics and Design Conference 2019, Presentation Number 520 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] In the conventional wheel device shown in Non-Patent Literature 1, at the time of rotation of the rim, a phenomenon in which the intermediate member greatly swings with respect to the rim, that is, a swing rotation of the intermediate member occurs, and the entire wheel device easily vibrates.

[0009] The present disclosure was completed in order to solve the above-described problems, and aims to obtain a wheel device capable of suppressing vibration.

[0010] MEANS FOR SOLVING THE PROBLEMS

[0011] The wheel device of the present disclosure includes a main body having a main body rotation portion that is rotatable; a ring-shaped intermediate member that surrounds the main body rotation portion; a ring-shaped rim that surrounds the intermediate member; a first elastic body that connects the intermediate member and the rim to each other in such a manner that the intermediate member is movable with respect to the rim along a first imaginary straight line that is orthogonal to an axis line of the intermediate member; a second elastic body that connects the intermediate member and the main body rotation portion to each other in such a manner that the intermediate member is movable with respect to the main body along a second imaginary straight line that is orthogonal to the axis line of the intermediate member and intersects the first imaginary straight line; and a damping structure portion that is provided to the main body, the damping structure portion having a counterweight that rotates in the same direction as a rotation direction of the main body rotation portion at a rotational speed that is 2 times a rotational speed of the main body rotation portion, the position of a center of gravity of the counterweight being a position that is lower than a rotational center line of the counterweight when a direction along the second imaginary straight line coincides with a vertical direction.

[0012] Effects of the Invention

[0013] According to the wheel device of the present disclosure, it is possible to suppress vibration of the wheel device. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a front view that shows the wheel device of Embodiment 1.

[0015] Figure 2 is a cross-sectional view along the line II-II of Figure 1

[0016] Figure 3 is a cross-sectional view along the line III-III of Figure 1

[0017] Figure 4 is a front view that shows the speed change mechanism of Figure 2

[0018] Figure 5 is a perspective view that shows the first elastic plate of Figure 1

[0019] Figure 6 is a perspective view that shows a state in which the first elastic plate of Figure 1 is fixed to the rim.

[0020] Figure 7 is a perspective view that shows the second elastic plate of Figure 1

[0021] Figure 8 is a perspective view that shows a state in which the second elastic plate of Figure 1 is fixed to the intermediate member.

[0022] ​​​​​Figure 9 It means to Figure 1 A schematic diagram of the wheel assembly model obtained by modeling the wheel assembly.

[0023] Figure 10 It means Figure 1 A front view of the wheel assembly moving on the track.

[0024] Figure 11 It means to Figure 10 A schematic diagram of the wheel assembly model obtained by modeling the wheel assembly.

[0025] Figure 12 It indicates being in a position with Figure 10 A front view of the wheel assembly when the wheel rim is subjected to impact forces from the track at different rotational positions.

[0026] Figure 13 It means to Figure 12 A schematic diagram of the wheel assembly model obtained by modeling the wheel assembly.

[0027] Figure 14 It means Figure 9 A schematic diagram illustrating the changes in the state of the wheel assembly as it rotates and moves along the track.

[0028] Figure 15 This is a graph showing the relationship between the rotational speed R [Hz] and time t [sec] of the wheel assembly in Comparative Example A1, Example B1, and Example C1 in the numerical analysis.

[0029] Figure 16 This is a graph showing the relationship between the displacement D1 [mm] of the main body of Comparative Example A1 in the Z-axis direction and time t [sec] in numerical analysis.

[0030] Figure 17 This is a graph showing the relationship between the displacement D1 [mm] of the main body of Example B1 in the Z-axis direction and time t [sec] in the numerical analysis.

[0031] Figure 18 This is a graph showing the relationship between the displacement D1 [mm] of the main body of embodiment C1 in the Z-axis direction and time t [sec] in the numerical analysis.

[0032] Figure 19 This is a cross-sectional view showing the wheel device of Embodiment 2.

[0033] Figure 20 This is a cross-sectional view showing the wheel device of Embodiment 3.

[0034] Figure 21This is a front view showing the wheel device of embodiment 4.

[0035] Figure 22 It is along Figure 21 A sectional view of the XXII-XXII line.

[0036] Figure 23 This is a cross-sectional view showing the wheel device of embodiment 5.

[0037] Figure 24 This is a cross-sectional view showing the wheel device of embodiment 6.

[0038] Figure 25 This is a cross-sectional view showing the wheel device of embodiment 7. Detailed Implementation

[0039] The embodiments will now be described with reference to the accompanying drawings.

[0040] Implementation method 1.

[0041] Figure 1 This is a front view showing the wheel assembly of Embodiment 1. Additionally, Figure 2 It is along Figure 1 A cross-sectional view along line II-II. And, Figure 3 It is along Figure 1 The figure shows a cross-sectional view along line III-III. In the figure, the wheel assembly 1 includes a rim 2, a main body 3, an intermediate component 4, a first connecting structure 5, a second connecting structure 6, and a vibration damping structure 7. In this embodiment, a railway vehicle wheel assembly installed on the body of a railway vehicle is used as the wheel assembly 1.

[0042] The rim 2 is annular in shape with axis P as its center. Furthermore, the inner circumferential surface 21 of the rim 2 is a cylindrical surface with axis P as its center. The rim 2 is made of metal such as iron. The wheel assembly 1 is mounted on the track with the outer circumferential surface of the rim 2 in contact with the track. The wheel assembly 1, mounted on the track, moves along the track according to the rotation of the rim 2.

[0043] The wheel assembly 1 is configured in an XYZ orthogonal coordinate system, which serves as a fixed coordinate system, with the axis P of the wheel rim 2 aligned with the Y-axis. The XYZ orthogonal coordinate system is set such that the Z-axis direction is the vertical direction, and the Y-axis direction is the width direction of the vehicle body. On the Z-axis, the upper vertical direction is designated as the positive side. On the Y-axis, the inner width direction of the vehicle body is designated as the positive side.

[0044] The main body 3 is disposed on the inner side of the wheel rim 2. In its natural state, without loads such as vehicle weight applied to the wheel assembly 1, the axis of the main body 3 is aligned with the axis P of the wheel rim 2. That is, the main body 3 is coaxially disposed with the wheel rim 2. In this embodiment, when the direction along the axis P of the wheel rim 2 is defined as the axial direction of the wheel rim 2, such as...Figure 2 as well as Figure 3 As shown, the size of the main body 3 in the axial direction of the wheel rim 2 is larger than the size of the wheel rim 2 in the axial direction of the wheel rim 2.

[0045] In addition, such as Figure 2 as well as Figure 3 As shown, the main body 3 has a fixed frame 31, a main shaft 32, a main motor 33, a rotating frame 34, and a speed change mechanism 35.

[0046] The fixed frame 31 is fixed to the body of the railway vehicle. The fixed frame 31 is a plate-shaped component orthogonal to the axis of the main body 3. A through hole 311 is provided on the fixed frame 31.

[0047] The spindle 32 is coaxially arranged with the axis of the main body 3. Furthermore, the spindle 32 has a first end 321 and a second end 322. The first end 321 is located on the positive side in the Y-axis direction compared to the second end 322. The first end 321 is disposed in a through hole 311. The first end 321 is rotatably mounted to the fixed frame 31 via a bearing 301 embedded in the through hole 311.

[0048] The main motor 33 and the speed change mechanism 35 are positioned between the first end 321 and the second end 322 along the axis of the main body 3, i.e., the Y-axis direction. The main motor 33 is positioned between the fixed frame 31 and the speed change mechanism 35.

[0049] The main motor 33 has a rotor 331 and an annular stator 332 surrounding the outer periphery of the rotor 331, which serves as the armature. Therefore, the main motor 33 is an internal rotor type motor. The axes of the rotor 331 and the stator 332 are aligned with the axis of the main motor 3.

[0050] The rotor 331 is fixed to the middle part of the main shaft 32 by means of thermoforming or other means. The middle part of the main shaft 32 is the portion of the main shaft 32 located between the first end 321 and the second end 322.

[0051] The stator 332 is fixed to the fixed frame 31. By supplying power to the stator 332, the rotor 331 rotates integrally with the main shaft 32 about the axis of the main body 3, relative to the fixed frame 31 and the stator 332. As a result, the main motor 33 generates torque that causes the rotating frame 34 to rotate.

[0052] The rotating frame 34 is arranged coaxially with the axis of the main body 3 as a rotating part of the main body. Furthermore, the rotating frame 34 is arranged to cover the main motor 33 and the transmission mechanism 35. The rotating frame 34 has a cylindrical portion 341 and a rotating plate portion 342 fixed to the cylindrical portion 341.

[0053] The cylindrical portion 341 surrounds the main motor 33 and the transmission mechanism 35. The outer peripheral surface 344 of the cylindrical portion 341 is a cylindrical surface centered on the axis of the main body 3. The outer diameter of the cylindrical portion 341 is smaller than the inner diameter of the wheel rim 2. The cylindrical portion 341 is rotatably mounted on the stator 332 via a bearing 302 embedded in the outer peripheral surface of the stator 332.

[0054] The rotating plate portion 342 is positioned closer to the second end 322 of the transmission mechanism 35, specifically on the negative side of the transmission mechanism 35 in the Y-axis direction. Furthermore, the rotating plate portion 342 is orthogonal to the axis of the main body 3. A through hole 343 is provided in the rotating plate portion 342 for the main shaft 32 to pass through. The rotating plate portion 342 is rotatably mounted to the main shaft 32 via a bearing 303 fitted into the through hole 343. Thus, the rotating frame 34 can rotate about the axis of the main body 3, respectively, relative to the fixed frame 31, the stator 332, and the main shaft 32.

[0055] A speed-changing mechanism 35 is disposed between the main motor 33 and the rotating plate portion 342. Furthermore, the speed-changing mechanism 35 transmits the torque of the main motor 33 to the rotating frame 34, such that the rotational speed of the rotating frame 34 is half the rotational speed of the rotor 331. Thus, by supplying power to the stator 332, the rotating frame 34 rotates in the same direction as the rotor 331 at half the rotational speed. The speed-changing mechanism 35 is a planetary gear mechanism having a sun gear 351, an internal gear 352, and multiple planetary gears 353.

[0056] Here, Figure 4 It means Figure 2 The front view of the transmission mechanism 35. The sun gear 351 is fixed to the middle part of the main shaft 32 by means of thermoforming or other means. Thus, the sun gear 351 rotates integrally with the main shaft 32 and the rotor 331 around the axis of the main body 3.

[0057] The internal gear 352 is an annular gear surrounding the sun gear 351. The internal gear 352 is coaxially arranged with the axis of the main body 3. Furthermore, the internal gear 352 is fixed to the stator 332. Therefore, when the main shaft 32 rotates relative to the stator 332, the sun gear 351 rotates relative to the internal gear 352. In this embodiment, as... Figure 2 as well as Figure 3 As shown, the outer diameter of the internal gear 352 is the same as the outer diameter of the stator 332.

[0058] like Figure 2 as well as Figure 3As shown, the cylindrical portion 341 of the rotating frame 34 is rotatably mounted on the internal gear 352 via a bearing 304 embedded in the outer peripheral surface of the internal gear 352. In this embodiment, ball bearings are used as each of the bearings 301 to 304. Each of the bearings 301 to 304 is not limited to ball bearings; for example, it may also be a radial bearing.

[0059] Each planetary gear 353 is disposed between the sun gear 351 and the internal gear 352. In this embodiment, the transmission mechanism 35 has four planetary gears 353. Each planetary gear 353 meshes with both the sun gear 351 and the internal gear 352. Each planetary gear 353 revolves around the sun gear 351 as a planetary gear carrier, with the sun gear 351 rotating relative to the internal gear 352. Each planetary gear 353 has a gear shaft 353a, a first gear portion 353b, and a second gear portion 353c.

[0060] The axis of the gear shaft 353a is aligned with the axis of the planetary gear 353. The gear shaft 353a is arranged parallel to the axis of the main body 3. Furthermore, the gear shaft 353a is rotatably mounted on the rotating plate portion 342 of the rotating frame 34. As a result, the rotational speed of the rotating frame 34 is synchronized with the revolution speed of each planetary gear 353 relative to the sun gear 351. The rotating frame 34 rotates together with each planetary gear 353 around the axis of the main body 3 while being synchronized with the revolution speed of each planetary gear 353 relative to the sun gear 351.

[0061] The first gear portion 353b and the second gear portion 353c are both external gears with multiple teeth on their outer periphery. The first gear portion 353b and the second gear portion 353c are fixed to the gear shaft 353a. Thus, the first gear portion 353b is coaxially fixed to the second gear portion 353c. The gear shaft 353a, the first gear portion 353b, and the second gear portion 353c rotate integrally around the axis of the planetary gear 353. The first gear portion 353b and the second gear portion 353c are adjacent to each other along the axial direction of the gear shaft 353a.

[0062] The first gear section 353b is located closer to the rotating plate section 342 than the second gear section 353c, that is, on the negative side of the second gear section 353c in the Y-axis direction. It should be noted that the first gear section 353b can also be located closer to the main motor 33 than the second gear section 353c, that is, on the positive side of the second gear section 353c in the Y-axis direction.

[0063] The first gear section 353b meshes with the internal gear 352. The second gear section 353c meshes with the sun gear 351. The number of teeth in the first gear section 353b and the number of teeth in the second gear section 353c are different. In this embodiment, the first gear section 353b has more teeth than the second gear section 353c.

[0064] In the transmission mechanism 35, the number of teeth in the sun gear 351, internal gear 352, first gear section 353b, and second gear section 353c is determined such that the rotational speed of the rotating frame 34 is half the rotational speed of the main shaft 32. That is, in the transmission mechanism 35, the number of teeth in each of the sun gear 351, internal gear 352, first gear section 353b, and second gear section 353c is determined such that the speed transmission ratio of the rotational speed of the rotating frame 34 to the rotational speed of the main shaft 32 is half. Therefore, when the rotor 331 and the main shaft 32 rotate one revolution as a unit, the rotating frame 34 rotates 1 / 2 revolution in the same direction as the rotation of the rotor 331 and the main shaft 32.

[0065] Here, the number of teeth of the sun gear 351 is set as z1, the number of teeth of the first gear section 353b is set as z2, the number of teeth of the second gear section 353c is set as z3, and the number of teeth of the internal gear 352 is set as z4. In this case, the speed transmission ratio i of the rotational speed of the rotating frame 34 relative to the rotational speed of the main shaft 32, that is, the speed transmission ratio i of the transmission mechanism 35, is expressed by the following equation (1).

[0066] i=1 / ((z2 / z1)·(z4 / z3)+1)…(1)

[0067] Assuming that the number of teeth z2 of the first gear section 353b is the same as the number of teeth z3 of the second gear section 353c, i.e., the relationship z2 = z3 holds, the speed transmission ratio i of the rotational speed of the rotating frame 34 relative to the rotational speed of the main shaft 32 is expressed by the following equation (2).

[0068] i = 1 / ((z4 / z1) + 1)…(2)

[0069] In this case, in order to make the speed transmission ratio i 1 / 2, the condition z1 = z4 needs to be met, that is, the number of teeth z1 of the sun gear 351 is the same as the number of teeth z4 of the internal gear 352, which makes it impossible to realize the speed change mechanism 35.

[0070] In contrast, in this embodiment, the number of teeth of the first gear section 353b and the number of teeth of the second gear section 353c are different. As a result, the number of teeth z1 of the sun gear 351 and the number of teeth z4 of the internal gear 352 can be different, and a speed change mechanism 35 in which the speed transmission ratio i of the rotational speed of the rotating frame 34 relative to the speed of the main shaft 32 is 1 / 2 can be realized.

[0071] like Figure 1 As shown, the intermediate component 4 is an annular component surrounding the rotating frame 34. The intermediate component 4 is disposed inside the rim 2. That is, the rim 2 is an annular component surrounding the intermediate component 4. In this embodiment, the wheel-mounted motor, including the main body 33, disposed inside the rim 2, is called the wheel assembly 1. The intermediate component 4 is a component distinct from both the rim 2 and the main body 3. In this embodiment, as... Figure 2 as well as Figure 3 As shown, the intermediate component 4 is positioned in the same location as the wheel rim 2 in the Y-axis direction, i.e., the axial direction of the wheel rim 2.

[0072] In its natural state, without any load such as the vehicle body weight applied to the wheel assembly 1, the axis of the intermediate component 4 is aligned with the axis P of the wheel rim 2. That is, the intermediate component 4 is coaxially arranged with the wheel rim 2. The inner circumferential surface 41 and the outer circumferential surface 42 of the intermediate component 4 are cylindrical surfaces centered on the axis of the intermediate component 4. The outer diameter of the intermediate component 4 is smaller than the inner diameter of the wheel rim 2. In addition, the inner diameter of the intermediate component 4 is larger than the outer diameter of the rotating frame 34. Therefore, the annular intermediate component 4 is arranged in the space between the wheel rim 2 and the main body 3.

[0073] The first connecting structure 5 is disposed between the wheel rim 2 and the intermediate component 4. In addition, the first connecting structure 5 has a pair of first elastic plates 51 that serve as first elastic bodies to connect the wheel rim 2 and the intermediate component 4 to each other.

[0074] The second connecting structure 6 is disposed between the intermediate component 4 and the rotating frame 34. In addition, the second connecting structure 6 has a pair of second elastic plates 61 that serve as second elastic bodies to connect the intermediate component 4 and the rotating frame 34 to each other.

[0075] Here, the structures of the pair of first elastic plates 51 and the pair of second elastic plates 61 will be described using the XYZ orthogonal coordinate system, which is the fixed coordinate system mentioned above, and the circumferential angle θ of the rim 2 relative to the reference position A set on the Z-axis of the XYZ orthogonal coordinate system.

[0076] like Figure 1As shown, when a specific straight line among the straight lines orthogonal to the axis of the intermediate component 4 is designated as the first imaginary straight line, a pair of first elastic plates 51 are respectively positioned at the intersection with the first imaginary straight line. The first imaginary straight line coincides with the straight line along the X-axis direction. Furthermore, the pair of first elastic plates 51 are positioned on opposite sides of each other relative to the axis of the intermediate component 4 in the direction along the first imaginary straight line, i.e., the X-axis direction. That is, one of the pair of first elastic plates 51 is positioned at a position where it has advanced θ = 90° circumferentially from the reference position A towards the rim 2, and the other first elastic plate 51 is positioned at a position where it has advanced θ = 270° circumferentially from the reference position A towards the rim 2. Since the rim 2 is coaxial with the intermediate component 4, the axis P of the rim 2 and the axis of the intermediate component 4 are located between the pair of first elastic plates 51.

[0077] Figure 5 It means Figure 1 A perspective view of the first elastic plate 51. Each first elastic plate 51 is a rectangular flat plate. The direction along the short side of the rectangle of the first elastic plate 51 is the width direction of the first elastic plate 51. The direction along the long side of the rectangle of the first elastic plate 51 is the length direction of the first elastic plate 51. Furthermore, the direction orthogonal to both the width and length directions of the first elastic plate 51 is the thickness direction of the first elastic plate 51.

[0078] like Figure 1 As shown, each of the first elastic plates 51 is orthogonal to a first imaginary straight line. That is, the thickness direction of each first elastic plate 51 is aligned with the direction along the first imaginary straight line, i.e., the X-axis direction. Furthermore, the width direction of each first elastic plate 51 is aligned with the axial direction of the rim 2, i.e., the Y-axis direction. Consequently, the length direction of each first elastic plate 51 is aligned with the Z-axis direction, which is orthogonal to both the X-axis and Y-axis directions. In other words, a pair of first elastic plates 51 are arranged parallel to a YZ plane orthogonal to the X-axis direction.

[0079] The two ends 511 of each first elastic plate 51 along its length are fixed to the inner circumferential surface 21 of the wheel rim 2 as a pair of fixing ends. The middle part 512 of each first elastic plate 51 along its length is fixed to the outer circumferential surface 42 of the intermediate component 4 as a single fixing plate part.

[0080] The rigidity of the first elastic plate 51 in the direction orthogonal to the thickness direction, i.e., the in-plane rigidity of the first elastic plate 51, is sufficiently higher than the rigidity of the first elastic plate 51 in the thickness direction, i.e., the out-of-plane rigidity of the first elastic plate 51. Therefore, it can be considered that the state in which the wheel rim 2 and the intermediate component 4 are connected via the first elastic plate 51 is equivalent to the state in which the wheel rim 2 and the intermediate component 4 are rigidly connected in the direction orthogonal to the thickness direction of the first elastic plate 51.

[0081] In contrast, since the out-of-plane stiffness of the first elastic plate 51 is sufficiently low compared to its in-plane stiffness, the first elastic plate 51 can elastically deform in its thickness direction. Through the elastic deformation of each first elastic plate 51 in its thickness direction, the intermediate component 4 can move relative to the rim 2 in the direction along the first imaginary straight line, i.e., the X-axis direction. That is, each first elastic plate 51 connects the intermediate component 4 and the rim 2 in such a way that the intermediate component 4 can move relative to the rim 2 along the first imaginary straight line. The rim 2 and the intermediate component 4 have a degree of freedom that allows them to move relative to each other only in the direction along the first imaginary straight line, i.e., the X-axis direction, due to the elastic deformation of each first elastic plate 51 in its thickness direction.

[0082] like Figure 1 As shown, at the position where the middle portion 512 of each first elastic plate 51 in the longitudinal direction is fixed as a single fixing plate portion on the outer peripheral surface 42 of the intermediate component 4, an outer peripheral planar portion 421 is formed. In this embodiment, two outer peripheral planar portions 421 are formed on the outer peripheral surface 42 of the intermediate component 4. The outer peripheral planar portions 421 are respectively formed at a position where the circumferential movement θ = 90° from the reference position A toward the rim 2 and at a position where the circumferential movement θ = 270° from the reference position A toward the rim 2. Each outer peripheral planar portion 421 is a planar portion orthogonal to the direction along the first imaginary straight line, i.e., the X-axis direction.

[0083] The middle portion 512 of the first elastic plate 51 along its length is fixed to the outer peripheral surface 42 of the intermediate member 4 in such a state that the surface orthogonal to the thickness direction of the first elastic plate 51 is in close contact with the outer peripheral plane portion 421 without gap. As a method for fixing the middle portion 512 of the first elastic plate 51 along its length to the outer peripheral surface 42 of the intermediate member 4, a fixing method using screws, bolts, welding, adhesives, etc. is used.

[0084] At the positions on the inner circumferential surface 21 of the rim 2 where each of the first elastic plates 51 is fixed as a pair of fixing ends along its length, a pair of stepped portions 211 are formed. Therefore, the inner circumferential surface 21 of the rim 2 has a pair of stepped portions 211 in the same number as the first elastic plates 51. In this embodiment, two sets of the pair of stepped portions 211 are formed on the inner circumferential surface 21 of the rim 2.

[0085] Figure 6 It means Figure 1A perspective view of the first elastic plate 51 fixed to the rim 2. A pair of stepped portions 211 are respectively embedded at both ends 511 along the length direction of the first elastic plate 51. The pair of stepped portions 211 face each other in the circumferential direction of the rim 2. Each pair of stepped portions 211 is composed of a bottom surface 211a of the stepped portion orthogonal to the direction along the first imaginary straight line, i.e., the X-axis direction, and an end surface 211b of the stepped portion extending from the bottom surface 211a toward the inner side of the rim 2.

[0086] Each of the two stepped portions 211 has a stepped end face 211b that is parallel to a plane containing the axis of the intermediate component 4 and a first imaginary straight line. Therefore, each of the stepped end faces 211b of the two stepped portions 211 is orthogonal to the Z-axis direction. The two stepped portions 211 are formed on the inner circumferential surface 21 of the rim 2 such that the two stepped end faces 211b face each other in the Z-axis direction.

[0087] The two ends 511 of the first elastic plate 51 along its length direction are fixed to the inner circumferential surface 21 of the wheel rim 2 in such a state that the surface orthogonal to the thickness direction of the first elastic plate 51 is in close contact with the bottom surface 211a of the step portion and the end face of the first elastic plate 51 along its length direction is in close contact with the end face 211b of the step portion. As a method for fixing the two ends 511 of the first elastic plate 51 along its length direction to the inner circumferential surface 21 of the wheel rim 2, fixing methods using screws, bolts, welding, adhesives, etc. are used.

[0088] When a line orthogonal to the axis of the intermediate component 4 but different from the first imaginary line is designated as the second imaginary line, a pair of second elastic plates 61 are respectively positioned at points intersecting the second imaginary line. In this embodiment, a line orthogonal to both the first imaginary line and the axis of the intermediate component 4 is designated as the second imaginary line. That is, in this embodiment, the second imaginary line is consistent with the line along the Z-axis direction. The pair of second elastic plates 61 are positioned on opposite sides of each other relative to the axis P of the rim 2 in the direction of the second imaginary line, i.e., the Z-axis direction. Therefore, one of the pair of second elastic plates 61 is positioned at a reference position A with θ = 0°, and the other second elastic plate 61 is positioned at a position θ = 180° forward from the reference position A toward the circumference of the rim 2. Since the rim 2 and the intermediate component 4 are coaxial, the axis P of the rim 2 and the axis of the intermediate component 4 are located between the pair of second elastic plates 61.

[0089] Figure 7 It means Figure 1A perspective view of the second elastic plate 61. Each second elastic plate 61 is a rectangular flat plate. The direction along the short side of the rectangle of the second elastic plate 61 is the width direction of the second elastic plate 61. The direction along the long side of the rectangle of the second elastic plate 61 is the length direction of the second elastic plate 61. Furthermore, the direction orthogonal to both the width and length directions of the second elastic plate 61 is the thickness direction of the second elastic plate 61.

[0090] like Figure 1 As shown, each of the second elastic plates 61 is orthogonal to a second imaginary straight line. That is, the thickness direction of each second elastic plate 61 is aligned with the direction along the second imaginary straight line, i.e., the Z-axis direction. Furthermore, the width direction of each second elastic plate 61 is aligned with the axial direction of the rim 2, i.e., the Y-axis direction. Consequently, the length direction of each second elastic plate 61 is aligned with the X-axis direction, which is orthogonal to both the Y-axis and Z-axis directions. In other words, a pair of second elastic plates 61 are arranged parallel to an XY plane orthogonal to the Z-axis direction.

[0091] The two ends 611 of each second elastic plate 61 along its length are fixed to the inner circumferential surface 41 of the intermediate component 4 as a pair of fixing ends. The middle part 612 of each second elastic plate 61 along its length is fixed to the outer circumferential surface 344 of the rotating frame 34 as a single fixing plate part.

[0092] The rigidity of the second elastic plate 61 in the direction orthogonal to the thickness direction, i.e., the in-plane rigidity of the second elastic plate 61, is sufficiently higher than the rigidity of the second elastic plate 61 in the thickness direction, i.e., the out-of-plane rigidity of the second elastic plate 61. Therefore, it can be considered that the state in which the intermediate component 4 and the rotating frame 34 are connected via the second elastic plate 61 is equivalent to the state in which the intermediate component 4 and the rotating frame 34 are rigidly connected in the direction orthogonal to the thickness direction of the second elastic plate 61.

[0093] In contrast, since the out-of-plane stiffness of the second elastic plate 61 is sufficiently low compared to its in-plane stiffness, the second elastic plate 61 can elastically deform in its thickness direction. Through the elastic deformation of each second elastic plate 61 in its thickness direction, the main body 3 can move relative to the intermediate member 4 in the direction along the second imaginary straight line, i.e., the Z-axis direction. That is, each second elastic plate 61 connects the intermediate member 4 and the rotating frame 34 to each other in such a way that the intermediate member 4 can move relative to the main body 3 along the second imaginary straight line. The intermediate member 4 and the main body 3 have a degree of freedom that allows them to move relative to each other only in the direction along the second imaginary straight line, i.e., the Z-axis direction, through the elastic deformation of each second elastic plate 61 in its thickness direction.

[0094] In the outer peripheral surface 344 of the rotating frame 34, at the position where the middle portion 612 of each second elastic plate 61 is fixed as a single fixing plate portion, an outer peripheral plane portion 345 is formed. In this embodiment, two outer peripheral plane portions 345 are formed on the outer peripheral surface 344 of the rotating frame 34. The outer peripheral plane portions 345 are respectively formed at a reference position A with θ = 0° and a position θ = 180° forward circumferentially from the reference position A towards the rim 2. Each outer peripheral plane portion 345 is a plane portion orthogonal to the direction along the second imaginary straight line, i.e., the Z-axis direction.

[0095] The middle portion 612 of the second elastic plate 61 along its length is fixed to the outer peripheral surface 344 of the rotating frame 34 in a state where the surface orthogonal to the thickness direction of the second elastic plate 61 is in close contact with the outer peripheral plane portion 345 without gap. As a method for fixing the middle portion 612 of the second elastic plate 61 along its length to the outer peripheral surface 344 of the rotating frame 34, a fixing method using screws, bolts, welding, adhesives, etc. is used.

[0096] At the positions where the two ends 611 of each second elastic plate 61 are fixed as a pair of fixing ends on the inner peripheral surface 41 of the intermediate component 4, a pair of stepped portions 411 are formed. Therefore, a pair of stepped portions 411, the same number as the second elastic plates 61, are formed on the inner peripheral surface 41 of the intermediate component 4. In this embodiment, two sets of the pair of stepped portions 411 are formed on the inner peripheral surface 41 of the intermediate component 4.

[0097] Figure 8 It means Figure 1 The second elastic plate 61 is fixed to the intermediate component 4 in a perspective view. A pair of stepped portions 411 are embedded at both ends 611 along the length direction of the second elastic plate 61. The pair of stepped portions 411 face each other in the circumferential direction of the intermediate component 4. Each pair of stepped portions 411 is composed of a bottom surface 411a of the stepped portion orthogonal to the direction along the second imaginary straight line, i.e., the Z-axis direction, and an end surface 411b of the stepped portion extending from the bottom surface 411a toward the inner side of the intermediate component 4.

[0098] Each of the two stepped portions 411 has a stepped end face 411b that is parallel to a plane containing the axis of the intermediate member 4 and a second imaginary straight line. Therefore, each of the stepped end faces 411b of the two stepped portions 411 is orthogonal to the X-axis direction. The two stepped portions 411 are formed on the inner circumferential surface 41 of the intermediate member 4 such that the two stepped end faces 411b face each other in the X-axis direction.

[0099] The two ends 611 of the second elastic plate 61 along its length are fixed to the inner peripheral surface 41 of the intermediate member 4 in such a state that the surface orthogonal to the thickness direction of the second elastic plate 61 is in contact with the bottom surface 411a of the step portion without gap, and the end face of the second elastic plate 61 along its length is in contact with the end face 411b of the step portion without gap. As a method for fixing the two ends 611 of the second elastic plate 61 along its length to the inner peripheral surface 41 of the intermediate member 4, a fixing method using screws, bolts, welding, adhesives, etc. is used.

[0100] like Figures 1-3 As shown, the vibration damping structure 7 is provided on the main body 3. In addition, the vibration damping structure 7 has a counterweight 71 as a balancer. The counterweight 71 is fixed to the second end 322 of the main shaft 32. Thus, the counterweight 71 is positioned further away from the position of the rotating plate 342 than the speed change mechanism 35, that is, on the negative side of the rotating frame 34 in the Y-axis direction.

[0101] The counterweight 71 rotates integrally with the main shaft 32 and the rotor 331 around the axis of the main body 3. That is, the rotation center line of the counterweight 71 is aligned with the axis of the main body 3. In addition, the rotational speed of the counterweight 71 is the same as that of the main shaft 32 and the rotor 331. As a result, the counterweight 71 rotates in the same direction as the rotation of the rotating frame 34 at a speed twice that of the rotating frame 34.

[0102] The counterweight 71 extends from the main shaft 32 in a specific radial direction orthogonal to the rotation center line of the counterweight 71. Therefore, the position of the center of gravity 71a of the counterweight 71 is set away from the rotation center line of the counterweight 71 in a direction orthogonal to it. In this embodiment, the position of the center of gravity 71a of the counterweight 71 is set away from the rotation center line of the counterweight 71 in a direction along a second imaginary straight line. The center of gravity 71a of the counterweight 71 moves along a circle centered on the rotation center line of the counterweight 71 as the counterweight 71 rotates.

[0103] Wheel assembly 1 is configured such that its direction along the second imaginary straight line is consistent with the Z-axis direction. Figure 1 In this state, the center of gravity 71a of the counterweight 71 is located on the negative side of the rotation center line of the counterweight 71 in the Z-axis direction. Therefore, when the thickness direction of each of the pair of second elastic plates 61 is aligned with the Z-axis direction and the pair of second elastic plates 61 are located on the Z-axis, the center of gravity 71a of the counterweight 71 becomes a position on the negative side of the rotation center line of the counterweight 71 in the Z-axis direction. That is, in the wheel assembly 1, when the direction along the second imaginary straight line is aligned with the vertical direction, the center of gravity 71a of the counterweight 71 becomes a position lower than the rotation center line of the counterweight 71.

[0104] Next, the operation of the wheel device 1 will be explained. Figure 9 It means toFigure 1 A schematic diagram of the wheel assembly model obtained by modeling the wheel assembly 1. The intermediate component 4 can move relative to the main body 3 in a direction along a second imaginary straight line through the elastic deformation of a pair of second elastic plates 61. The movement of the intermediate component 4 relative to the main body 3 in directions other than along the second imaginary straight line is rigidly limited by the in-plane rigidity of the pair of second elastic plates 61.

[0105] The intermediate component 4 can move relative to the rim 2 in a direction along a first imaginary straight line through the elastic deformation of a pair of first elastic plates 51. The movement of the intermediate component 4 relative to the rim 2 in directions other than the first imaginary straight line is rigidly limited in the plane by the pair of first elastic plates 51.

[0106] Thus, in the wheel assembly 1, a vibration system with two translational degrees of freedom is formed in which the intermediate component 4 can move freely relative to the main body 3 and the wheel rim 2 within the XZ plane containing the first imaginary straight line and the second imaginary straight line.

[0107] Each of the first elastic plates 51 and each of the second elastic plates 61 is in-plane rigid in the circumferential direction of the rim 2. Therefore, the elastic deformation of each of the first elastic plates 51 and each of the second elastic plates 61 is restricted in the circumferential direction of the rim 2. Consequently, the connection state of the intermediate component 4 relative to the rim 2 and the connection state of the intermediate component 4 relative to the rotating frame 34 can be considered as a rigid connection in the circumferential direction of the rim 2. Therefore, the rotational speed of the rim 2 is the same as the rotational speed of the intermediate component 4. Furthermore, the rotational speed of the intermediate component 4 is the same as the rotational speed of the rotating frame 34.

[0108] Figure 10 It means Figure 1 A front view of the wheel assembly 1 moving on the track. Additionally, Figure 11 It means to Figure 10 A schematic diagram of the wheel assembly model obtained by modeling the wheel assembly 1. With the wheel assembly 1 placed on the track 10, the outer circumferential surface of the wheel rim 2 is in contact with the track 10. The wheel assembly 1 moves on the track 10 by rotating the wheel rim 2.

[0109] When the rotor 331 rotates by supplying power to the stator 332, the main shaft 32 and the sun gear 351 rotate integrally with the rotor 331. As the sun gear 351 rotates, each planetary gear 353 revolves around the sun gear 351. Consequently, the rotating frame 34 rotates about the axis of the main body 3. Thus, the torque of the main motor 33 is transmitted to the rotating frame 34.

[0110] The torque of the main motor 33 transmitted to the rotating frame 34 is transmitted from the rotating frame 34 to the intermediate component 4 via a pair of second elastic plates 61. At this time, the direction of the torque transmitted from the rotating frame 34 to each of the second elastic plates 61 is consistent with the direction of the in-plane rigidity of each of the second elastic plates 61. As a result, the elastic deformation of each of the second elastic plates 61 is restricted, and the torque of the rotating frame 34 is effectively transmitted to the intermediate component 4.

[0111] The torque transmitted to the intermediate component 4 is transmitted to the wheel rim 2 via a pair of first elastic plates 51. At this time, the direction of the torque transmitted from the intermediate component 4 to each of the first elastic plates 51 is consistent with the direction of the in-plane rigidity of each first elastic plate 51. Therefore, the elastic deformation of each first elastic plate 51 is restricted, and the torque transmitted to the intermediate component 4 is effectively transmitted to the wheel rim 2. Consequently, the wheel rim 2 rotates. Therefore, in the wheel assembly 1, when the rotating frame 34 rotates, the wheel rim 2 and the intermediate component 4 rotate in the same direction as the rotation of the rotating frame 34.

[0112] The track 10 is composed of multiple unit tracks 10a connected continuously. Steps may sometimes form at the joints between two adjacent unit tracks 10a. In this case, when the wheel assembly 1 passes through the joint between two unit tracks 10a, the wheel rim 2 is subjected to an impact force from the track 10.

[0113] like Figure 10 as well as Figure 11 As shown, when the rim 2 is subjected to an impact force along the direction of the second imaginary straight line, i.e., the direction consistent with the Z-axis, the intermediate component 4 moves only relative to the main body 3 in the direction along the second imaginary straight line due to the elastic deformation of each of the second elastic plates 61. Therefore, the impact force on the rim 2 is absorbed by the pair of second elastic plates 61 and is difficult to transmit to the main body 3.

[0114] in addition, Figure 12 It indicates being in a position with Figure 10 A front view of the wheel assembly 1 when the wheel rim 2 is subjected to impact force from the track 10 at different rotational positions. Furthermore, Figure 13 It means to Figure 12 A schematic diagram of the wheel assembly model obtained by modeling the wheel assembly 1. For example... Figure 12 as well as Figure 13As shown, when the rim 2 is subjected to an impact force from the track 10 in a direction inconsistent with both the direction along the first imaginary straight line and the direction along the second imaginary straight line, the intermediate component 4 moves relative to the rim 2 in the direction along the first imaginary straight line, and moves relative to the main body 3 in the direction along the second imaginary straight line. When the intermediate component 4 moves relative to the rim 2 in the direction along the first imaginary straight line, each of the first elastic plates 51 elastically deforms. When the intermediate component 4 moves relative to the main body 3 in the direction along the second imaginary straight line, each of the second elastic plates 61 elastically deforms. Therefore, the impact force received by the rim 2 is absorbed by each of the first elastic plates 51 and each of the second elastic plates 61, making it difficult to transmit to the main body 3.

[0115] Figure 14 It means Figure 9 This is a schematic diagram illustrating the changes in the state of the wheel assembly 1 as it rotates and moves on the track 10. It should be noted that... Figure 14 In this context, the direction along the first imaginary straight line is defined as the first direction ξ, and the direction along the second imaginary straight line is defined as the second direction η. When the wheel assembly 1 moves on the track 10, a phenomenon occurs in which the intermediate component 4 oscillates and rotates relative to the wheel rim 2 and the main body 3, i.e., the oscillation and rotation of the intermediate component 4. Figure 14 The state changes of the wheel device 1 are shown from the state where the second direction η is aligned with the Z-axis to the state where the second direction η is aligned with the X-axis.

[0116] exist Figure 14 During the 90° rotation of the wheel assembly 1, the intermediate component 4 oscillates and rotates 180° relative to the rim 2 and the main body 3. That is, the intermediate component 4 oscillates and rotates at a frequency twice that of the wheel assembly 1. When the intermediate component 4 oscillates and rotates, the centrifugal force generated by the intermediate component 4 causes the entire wheel assembly 1 to vibrate. In the wheel assembly 1, the vibration of the entire wheel assembly 1 is suppressed by activating the counterweight 71 in the vibration damping structure 7.

[0117] When the wheel assembly 1 rotates 90° from its initial state where the second direction η aligns with the Z-axis direction (i.e., the vertical direction), the second direction η aligns with the X-axis direction. At this time, since the first direction ξ aligns with the Z-axis direction, therefore, as... Figure 14 As shown in the wheel assembly 1 on the right, each of the first elastic plates 51 elastically deforms. At this time, the intermediate component 4 moves relative to the rim 2 in the negative Z-axis direction, i.e., downward. As a result, centrifugal force acts on the intermediate component 4 in the negative Z-axis direction.

[0118] On the other hand, in the initial state where the second direction η aligns with the Z-axis, the center of gravity 71a of the counterweight 71 is located on the negative side of the Z-axis direction, i.e., below, compared to the rotational center line of the counterweight 71. Furthermore, the counterweight 71 rotates at twice the rotational speed of the rotating frame 34 in the same direction as the rotation of the rotating frame 34. Therefore, before the wheel assembly 1 rotates 90° from its initial state to align the second direction η with the X-axis, the counterweight 71 rotates 180°, and the center of gravity 71a of the counterweight 71 moves upwards and to the positive side of the Z-axis direction, compared to the rotational center line of the counterweight 71. As a result, centrifugal force acts on the counterweight 71 in the positive Z-axis direction.

[0119] Therefore, as Figure 14 As shown in the wheel assembly 1 on the right, when the second direction η is aligned with the Z-axis direction, the centrifugal force acts on the counterweight 71 in the direction that counteracts the centrifugal force acting on the intermediate component 4 towards the negative side of the Z-axis direction, i.e., on the positive side of the Z-axis direction. That is, the centrifugal force acting on the counterweight 71 acts in the direction that counteracts the excitation force caused by the oscillation and rotation of the intermediate component 4.

[0120] Next, the eccentricity of the counterweight 71 and its mass will be explained. The eccentricity of the counterweight 71 is the distance from the rotation center line of the counterweight 71 to its center of gravity 71a. Let the mass of the intermediate component 4 be M, the rotational angular velocity of the wheel assembly 1 be ω, the mass of the counterweight 71 be m, and the eccentricity of the counterweight 71 be L. Furthermore, as... Figure 14 As shown, in the displacement caused by the oscillation and rotation of the intermediate component 4, the displacement in the Z-axis direction, i.e. the vertical direction, i.e. the vertical displacement of the intermediate component 4, is set as D.

[0121] In this case, the centrifugal force acting on the intermediate component 4 by the oscillation of the vibration system including the intermediate component 4 is represented by the following equation (3).

[0122] M·D·ω 2 …(3)

[0123] In contrast, when the wheel device 1 rotates one revolution, the counterweight 71 rotates two revolutions. Therefore, the rotational angular velocity of the counterweight 71 is 2ω. Thus, the centrifugal force acting on the counterweight 71 is expressed by the following equation (4).

[0124] m·L·(2ω) 2 …(4)

[0125] The condition for maximally suppressing the vibration caused by the oscillating rotation of the intermediate component 4 is the equilibrium condition of equations (3) and (4). Therefore, the condition for maximally suppressing the vibration caused by the oscillating rotation of the intermediate component 4 is expressed by the following equation (5).

[0126] M·D=4·m·L…(5)

[0127] Therefore, when the product of the eccentricity L of the counterweight 71 and the mass m of the counterweight 71 is equal to 1 / 4 of the product of the vertical displacement D of the intermediate component 4 and the mass M of the intermediate component 4 during the rotation of the rim 2, vibration caused by the oscillation and rotation of the intermediate component 4 can be effectively suppressed. In this embodiment, the product of the eccentricity L of the counterweight 71 and the mass m of the counterweight 71 is equal to 1 / 4 of the product of the vertical displacement D of the intermediate component 4 and the mass M of the intermediate component 4 during the rotation of the rim 2.

[0128] Next, the displacement D1 of the main body 3 in the Z-axis direction when the rotational speed R [Hz] of the wheel assembly 1 changes linearly from 0 [Hz] to 20 [Hz] is determined by numerical analysis. In the numerical analysis, the wheel assembly of Comparative Example A1 (excluding the vibration damping structure 7), the wheel assembly of Example B1 (with M = 60 [kg], m = 0.05 [kg], L = 200 [mm]), and the wheel assembly of Example C1 (with M = 60 [kg], m = 0.1 [kg], L = 200 [mm]) are taken as the analysis objects. Therefore, the embodiment that does not satisfy the above equation (5) is taken as Example B1, and the embodiment that satisfies the above equation (5) is taken as Example C1. It should be noted that in the wheel assembly 1, the smaller the vibration of the wheel assembly 1 caused by the oscillating rotation of the intermediate component 4, the smaller the displacement D1 of the main body 3 in the Z-axis direction.

[0129] Figure 15 This is a graph showing the relationship between the rotational speed R [Hz] and time t [sec] of the wheel assembly in Comparative Example A1, Example B1, and Example C1 in the numerical analysis. Additionally, Figure 16 This is a graph showing the relationship between the displacement D1 [mm] of the main body 3 in the Z-axis direction and time t [sec] of comparative example A1 in numerical analysis. Furthermore, Figure 17 This is a graph showing the relationship between the displacement D1 [mm] of the main body 3 in the Z-axis direction and time t [sec] of embodiment B1 in the numerical analysis. Additionally, Figure 18 This is a graph showing the relationship between the displacement D1 [mm] of the main body 3 in embodiment C1 in the Z-axis direction and time t [sec] in numerical analysis.

[0130] like Figures 15-18 As shown, in Comparative Example A1, the vibration of the main body 3 increases around 3.5 [sec]. In contrast, in Examples B1 and C1, the vibration of the main body 3 decreases compared to Comparative Example A1. Furthermore, it is known that in Example C1, which does not satisfy the above equation (5), the vibration of the main body 3 decreases compared to Example B1, which does not satisfy the above equation (5).

[0131] In this wheel assembly 1, each first elastic plate 51 is orthogonal to a first imaginary straight line, which is orthogonal to the axis of the intermediate component 4. Furthermore, each second elastic plate 61 is orthogonal to a second imaginary straight line different from the first imaginary straight line. Therefore, the rigidity of each first elastic plate 51 and each second elastic plate 61 in the circumferential direction of the rim 2 can be improved. This limits the elastic deformation of each first elastic plate 51 and each second elastic plate 61 in the rotational direction of the rim 2, preventing unwanted vibrations of the rim 2 relative to the body 3 in the rotational direction of the rim 2. Therefore, torque can be transmitted from the body 3 to the rim 2 more reliably. Furthermore, when the rim 2 is subjected to an external impact force, at least one of the first elastic plate 51 and the second elastic plate 61 can elastically deform while moving the body 3 relative to the rim 2. This allows at least one of the first elastic plate 51 and the second elastic plate 61 to absorb the impact force received by the rim 2. Therefore, the impact force transmitted from the rim 2 to the body 3 can be suppressed.

[0132] Furthermore, a second imaginary line orthogonal to each of the second elastic plates 61 is orthogonal to a first imaginary line orthogonal to each of the first elastic plates 51. Therefore, each of the first elastic plates 51 and each of the second elastic plates 61 can be evenly arranged in the circumferential direction of the wheel rim 2. This allows for the equalization of the shock-absorbing force on the wheel rim 2 in the circumferential direction.

[0133] Furthermore, the axis of the intermediate component 4 is located between a pair of first elastic plates 51 and between a pair of second elastic plates 61. Therefore, the connection between the intermediate component 4 and the wheel rim 2, and the connection between the main body 3 and the intermediate component 4, can be stabilized. This allows for more reliable suppression of malfunctions in the wheel assembly 1, thereby improving the reliability of the wheel assembly 1.

[0134] Furthermore, the two ends 511 of the first elastic plate 51 along its length are fixed to the wheel rim 2, and the middle part 512 along its length is fixed to the intermediate component 4. Therefore, the first elastic plate 51 can be elastically deformed in the thickness direction, and the fixing state of the first elastic plate 51 relative to the wheel rim 2 and the intermediate component 4 can be made more reliable.

[0135] Furthermore, the two ends 611 of the second elastic plate 61 along its length are fixed to the intermediate component 4, and the middle part 612 along its length is fixed to the rotating frame 34 of the main body 3. Therefore, the second elastic plate 61 can be elastically deformed in the thickness direction, and the fixed state of the second elastic plate 61 relative to the intermediate component 4 and the rotating frame 34 can be made more reliable.

[0136] Furthermore, at the position on the inner circumferential surface 21 of the rim 2 where the two ends 511 of the first elastic plate 51 in the longitudinal direction are fixed as a pair of fixing ends, a pair of stepped portions 211 are formed for the two ends 511 of the first elastic plate 51 in the longitudinal direction to be respectively inserted. Therefore, the first elastic plate 51 can be fixed to the rim 2 more reliably, and the positional displacement of the first elastic plate 51 relative to the rim 2 can be prevented more reliably.

[0137] Furthermore, at the position on the inner peripheral surface 41 of the intermediate component 4 where the two ends 611 of the second elastic plate 61 in the longitudinal direction are fixed as a pair of fixing ends, a pair of stepped portions 411 are formed for the two ends 611 of the second elastic plate 61 in the longitudinal direction to be respectively inserted. Therefore, the second elastic plate 61 can be fixed to the intermediate component 4 more reliably, and the positional displacement of the second elastic plate 61 relative to the intermediate component 4 can be prevented more reliably.

[0138] Furthermore, the vibration damping structure 7 includes a counterweight 71 that rotates at twice the rotational speed of the rotating frame 34 in the same direction as the rotation of the rotating frame 34. Moreover, when the direction along the second imaginary straight line aligns with the vertical direction, the center of gravity 71a of the counterweight 71 is positioned below the rotational centerline of the counterweight 71. Therefore, the centrifugal force of the counterweight 71 can counteract at least a portion of the excitation force generated by the movement of the intermediate component 4 relative to the rim 2 and the main body 3. This suppresses the overall vibration of the wheel assembly 1 caused by the oscillating rotation of the intermediate component 4.

[0139] Furthermore, the main body 3 has a main motor 33 that generates torque to rotate the rotating frame 34. Therefore, the drive source for rotating the wheel assembly 1 can be arranged inside the intermediate component 4. As a result, the wheel assembly 1 can be miniaturized.

[0140] Furthermore, the main body 3 has a speed-changing mechanism 35 that transmits the torque of the main motor 33 to the rotating frame 34, so that the rotational speed of the rotating frame 34 is half the rotational speed of the rotor 331. Additionally, the counterweight 71 rotates integrally with the rotor 331. Therefore, it is possible to more reliably make the rotational speed of the counterweight 71 twice the rotational speed of the rotating frame 34.

[0141] Furthermore, the transmission mechanism 35 is a planetary gear mechanism comprising a sun gear 351, an internal gear 352, and multiple planetary gears 353. Therefore, with a simple structure, the rotational speed of the counterweight 71 can be twice the rotational speed of the rotating frame 34. This allows for more reliable suppression of malfunctions in the wheel assembly 1, and more reliable improvement in the reliability of the wheel assembly 1.

[0142] Furthermore, the product of the eccentricity L of the counterweight 71 and the mass m of the counterweight 71 is equal to 1 / 4 of the product of the vertical displacement D of the intermediate component 4 during the rotation of the wheel rim 2 and the mass M of the intermediate component 4. Therefore, the centrifugal force of the counterweight 71 can effectively counteract the excitation force caused by the oscillation and rotation of the intermediate component 4. As a result, the vibration of the wheel assembly 1 as a whole can be effectively suppressed.

[0143] Furthermore, if the rotation center line of the counterweight 71 deviates from the axis of the main body 3, an unwanted rotational torque will be generated in the counterweight 71, which will not help suppress the vibration caused by the oscillating rotation of the intermediate component 4. In this embodiment, the rotation center line of the counterweight 71 is aligned with the axis of the main body 3. As a result, the generation of unwanted rotational torque can be suppressed. In addition, it is not necessary to use an additional counterweight to suppress the generation of unwanted rotational torque. Therefore, vibration caused by the oscillating rotation of the intermediate component 4 can be efficiently suppressed with a simple structure.

[0144] Implementation method 2.

[0145] Figure 19 This is a cross-sectional view showing the wheel device according to Embodiment 2. It should be noted that... Figure 19 It is the same as in implementation method 1 Figure 2 The corresponding figure shows that a rotating plate portion 342 of a rotating frame 34 is rotatably mounted on the second end 322 of the main shaft 32 via a bearing 303. The main shaft 32 extends towards the positive side in the Y-axis direction compared to the fixed frame 31. As a result, the first end 321 of the main shaft 32 is located inside the width direction of the vehicle body compared to the fixed frame 31.

[0146] The counterweight 71 is fixed to the first end 321 of the main shaft 32. Therefore, the counterweight 71 is positioned inside the width direction of the vehicle body, which is closer to the fixed frame 31 than the fixed frame 31, that is, on the positive side of the fixed frame 31 in the Y-axis direction.

[0147] The structure of the counterweight 71 is the same as in Embodiment 1. Therefore, the counterweight 71 rotates at twice the rotational speed of the rotating frame 34 in the same direction as the rotation of the rotating frame 34. Furthermore, the center of gravity 71a of the counterweight 71 moves along a circle centered on the rotational centerline of the counterweight 71 as the counterweight 71 rotates.

[0148] The wheel assembly 1 is configured such that, when the direction of the second imaginary straight line is aligned with the Z-axis direction, the center of gravity 71a of the counterweight 71 is located on the negative side of the Z-axis direction compared to the rotation center line of the counterweight 71. Therefore, in the wheel assembly 1, when the direction of the second imaginary straight line is aligned with the vertical direction, the center of gravity 71a of the counterweight 71 is located below the rotation center line of the counterweight 71. The other structures in Embodiment 2 are the same as in Embodiment 1.

[0149] In this wheel assembly 1, a counterweight 71 is fixed to the first end 321 of the main shaft 32. Therefore, the counterweight 71 can be positioned inside the vehicle body in the width direction of the fixed frame 31. This allows for a reduction in the size of the wheel assembly 1, which is positioned outside the fixed frame 31 in the width direction of the vehicle body. Consequently, the wheel assembly 1 can be made more compact relative to the side of the vehicle body, increasing the design freedom of the wheel assembly 1.

[0150] Implementation method 3.

[0151] Figure 20 This is a cross-sectional view showing the wheel device according to Embodiment 3. It should be noted that... Figure 20 It is the same as in implementation method 1 Figure 2 The corresponding figure shows that a rotating plate portion 342 of a rotating frame 34 is fixed to the second end 322 of the main shaft 32. Thus, the rotating frame 34 rotates integrally with the main shaft 32 and the rotor 331 around the axis of the main body 3. Therefore, the rotating frame 34 rotates at the same speed as the main shaft 32 and the rotor 331, driven by the torque of the main motor 33.

[0152] The vibration damping structure 7 is positioned inside the body 3 in the width direction, specifically on the side closest to the Y-axis of the body 3. Furthermore, the vibration damping structure 7 includes a counterweight 71 and a transmission mechanism 72. The counterweight 71 is mounted to the main shaft 32 via the transmission mechanism 72. The transmission mechanism 72 transmits the torque of the main motor 33 to the counterweight 71.

[0153] The transmission mechanism 72 is positioned inside the main shaft 32 in the width direction of the vehicle body, specifically on the positive side of the main shaft 32 in the Y-axis direction. Furthermore, the transmission mechanism 72 transmits the torque of the main motor 33 to the counterweight 71, causing the counterweight 71 to rotate at twice the speed of the rotor 331. Therefore, by supplying power to the stator 332, the counterweight 71 rotates at twice the speed of the rotating frame 34 in the same direction as the rotating frame 34.

[0154] The transmission mechanism 72 includes a sun gear 721, an internal gear 722, multiple planetary gears 723, a main shaft fixing component 725, and a transmission mechanism output shaft 726. The sun gear 721, internal gear 722, and multiple planetary gears 723 constitute a planetary gear mechanism. The structure of the planetary gear mechanism is the same as that of the transmission mechanism 35 in Embodiment 1.

[0155] The main shaft fixing component 725 is fixed to the first end 321 of the main shaft 32. Thus, the main shaft fixing component 725 rotates integrally with the main shaft 32 and the rotor 331 about the axis of the main body 3. The main shaft fixing component 725 is located inside the width direction of the vehicle body, that is, on the positive side of the Y-axis direction, compared to the fixed frame 31. The main shaft fixing component 725 is a circular plate orthogonal to the axis of the main body 3. The outer diameter of the main shaft fixing component 725 is larger than the outer diameter of the main shaft 32.

[0156] The sun gear 721 is coaxially arranged with the axis of the main body 3. In addition, the sun gear 721 is located inside the width direction of the vehicle body, which is closer to the positive side of the main shaft fixing member 725 in the Y-axis direction.

[0157] The internal gear 722 is an annular gear surrounding the sun gear 721. Therefore, the internal gear 722 is located inside the fixed frame 31 in the width direction of the vehicle body, that is, on the positive side of the fixed frame 31 in the Y-axis direction. The internal gear 722 is coaxially arranged with the axis of the main body 3. Furthermore, the internal gear 722 is fixed to the fixed frame 31.

[0158] Each planetary gear 723 is disposed between the sun gear 721 and the internal gear 722. Each planetary gear 723 meshes with both the sun gear 721 and the internal gear 722. Furthermore, each planetary gear 723 is mounted on the spindle fixing member 725. The sun gear 721 is supported by being clamped between each planetary gear 723. The spindle fixing member 725 rotates integrally with the spindle 32 and the rotor 331, thereby causing each planetary gear 723 to revolve around the sun gear 721 about the axis of the main body 3. The revolution speed of each planetary gear 723 relative to the sun gear 721 is the same as the rotational speed of the rotor 331. The sun gear 721 rotates about the axis of the main body 3 while being synchronized with the revolution speed of each planetary gear 723 relative to the sun gear 721. Each planetary gear 723 has a gear shaft 723a, a first gear portion 723b, and a second gear portion 723c.

[0159] The axis of the gear shaft 723a is aligned with the axis of the planetary gear 723. The gear shaft 723a is arranged parallel to the axis of the main body 3. Furthermore, the gear shaft 723a is rotatably mounted on the spindle fixing member 725.

[0160] The first gear portion 723b and the second gear portion 723c are both external gears with multiple teeth on their outer periphery. The first gear portion 723b and the second gear portion 723c are fixed to the gear shaft 723a. Thus, the first gear portion 723b is coaxially fixed to the second gear portion 723c. The gear shaft 723a, the first gear portion 723b, and the second gear portion 723c rotate integrally around the axis of the planetary gear 723. The first gear portion 723b and the second gear portion 723c are adjacent to each other along the axial direction of the gear shaft 723a.

[0161] The first gear section 723b meshes with the internal gear 722. The second gear section 723c meshes with the sun gear 721. The number of teeth in the first gear section 723b and the number of teeth in the second gear section 723c are different. In this embodiment, the first gear section 723b has more teeth than the second gear section 723c.

[0162] The second gear portion 723c is located closer to the fixed frame 31 than the first gear portion 723b, that is, on the negative side of the first gear portion 723b in the Y-axis direction. It should be noted that the second gear portion 723c can also be located further away from the fixed frame 31 than the first gear portion 723b, that is, on the positive side of the first gear portion 723b in the Y-axis direction.

[0163] The transmission mechanism output shaft 726 is fixed to the sun gear 721. The transmission mechanism output shaft 726 protrudes from the sun gear 721 toward the inside of the vehicle body in the width direction, that is, from the positive side of the sun gear 721 toward the Y-axis. The transmission mechanism output shaft 726 is coaxially arranged with the axis of the main body 3. Thus, the transmission mechanism output shaft 726 rotates integrally with the sun gear 721 about the axis of the main body 3.

[0164] In the transmission mechanism 72, the number of teeth of the sun gear 721, internal gear 722, first gear section 723b, and second gear section 723c is determined such that the rotational speed of the transmission mechanism output shaft 726 is twice the rotational speed of the rotor 331. That is, in the transmission mechanism 72, the number of teeth of the sun gear 721, internal gear 722, first gear section 723b, and second gear section 723c is determined such that the speed transmission ratio of the rotational speed of the transmission mechanism output shaft 726 to the rotational speed of the rotor 331 is 2. Therefore, when the rotor 331 rotates one revolution, the transmission mechanism output shaft 726 rotates two revolutions in the same direction as the rotation of the rotor 331.

[0165] The counterweight 71 is fixed to the output shaft 726 of the transmission mechanism. Thus, the counterweight 71 rotates integrally with the output shaft 726 of the transmission mechanism. In addition, the counterweight 71 is positioned inside the planetary gear mechanism of the transmission mechanism 72 in the width direction of the vehicle body, that is, on the positive side of the planetary gear mechanism of the transmission mechanism 72 in the Y-axis direction.

[0166] The structure of the counterweight 71 is the same as in Embodiment 1. Therefore, the counterweight 71 rotates at twice the rotational speed of the rotating frame 34 in the same direction as the rotation of the rotating frame 34. The rotation centerline of the counterweight 71 is aligned with the axis of the main body 3. The center of gravity 71a of the counterweight 71 moves along a circle centered on the rotation centerline of the counterweight 71 as the counterweight 71 rotates.

[0167] The wheel assembly 1 is configured such that, when the direction along the second imaginary straight line is aligned with the Z-axis direction, the center of gravity 71a of the counterweight 71 is located on the negative side of the Z-axis direction compared to the rotation center line of the counterweight 71. Therefore, in the wheel assembly 1, when the direction along the second imaginary straight line is aligned with the vertical direction, the center of gravity 71a of the counterweight 71 is located below the rotation center line of the counterweight 71. The other structures in Embodiment 3 are the same as in Embodiment 1.

[0168] In this wheel assembly 1, the rotating frame 34 rotates integrally with the rotor 331. Furthermore, the transmission mechanism 72 transmits the torque of the main motor 33 to the counterweight 71, ensuring that the rotational speed of the counterweight 71 is twice that of the rotor 331. Therefore, it is possible to more reliably ensure that the rotational speed of the counterweight 71 is twice that of the rotating frame 34. Additionally, the transmission mechanism 72 only needs to transmit the torque of the main motor 33 to the counterweight 71, without needing to transmit the torque of the main motor 33 to the rotating frame 34, which is heavier than the counterweight 71. This allows for miniaturization of the transmission mechanism 72.

[0169] Furthermore, the vibration damping structure 7 is positioned inside the vehicle body in the width direction, closer to the main body 3. Therefore, the counterweight 71 and the transmission mechanism 72 can be positioned inside the vehicle body in the width direction, closer to the fixed frame 31 fixed to the vehicle body. Consequently, similar to Embodiment 2, the boundary of the wheel assembly 1 relative to the side of the vehicle body can be made more compact, further increasing the design freedom of the wheel assembly 1.

[0170] Implementation method 4.

[0171] Figure 21 This is a front view showing the wheel assembly of embodiment 4. Additionally, Figure 22 It is along Figure 21 A sectional view along line XXII-XXII. It should be noted that... Figure 21 It is the same as in implementation method 1 Figure 1 The corresponding diagram. Figure 22 It is the same as in implementation method 1 Figure 2 The corresponding figure shows that the counterweight 71 is fixed to the second end 322 of the main shaft 32. The counterweight 71 has a fixing seat 711 and a counterweight body 712.

[0172] The fixing base 711 is a rod-shaped component orthogonal to the axis of the main body 3. The fixing base 711 is arranged along a second imaginary straight line. The fixing base 711 is fixed to the second end 322 in a state of passing through the second end 322. The fixing base 711 protrudes from the outer peripheral surface of the second end 322 in a direction along the second imaginary straight line.

[0173] The counterweight body 712 is mounted on the fixed base 711. For example, a threaded rod is used as the fixed base 711, and a nut screwed into the fixed base 711 is used as the counterweight body 712. The counterweight body 712 can move relative to the fixed base 711 along the length of the fixed base 711. Thus, the position of the counterweight body 712 relative to the fixed base 711 can be adjusted along the length of the fixed base 711. In the counterweight 71, by adjusting the position of the counterweight body 712 relative to the fixed base 711 along the length of the fixed base 711, the position of the center of gravity 71a of the counterweight 71 is adjusted. That is, for the counterweight 71, the distance from the rotation center line of the counterweight 71 to the center of gravity 71a of the counterweight 71, i.e., the eccentricity L of the counterweight 71, can be adjusted.

[0174] The wheel assembly 1 is configured such that, when the direction along the second imaginary straight line is aligned with the Z-axis direction, the center of gravity 71a of the counterweight 71 is located on the negative side of the Z-axis direction compared to the rotation center line of the counterweight 71. Therefore, in the wheel assembly 1, when the direction along the second imaginary straight line is aligned with the vertical direction, the center of gravity 71a of the counterweight 71 is located below the rotation center line of the counterweight 71. The other structures in Embodiment 4 are the same as in Embodiment 1.

[0175] In such a wheel assembly 1, the eccentricity L of the counterweight 71 can be adjusted. Therefore, based on the vertical displacement D of the intermediate component 4, which is determined by the mass of the vehicle, the eccentricity L of the counterweight 71 can be adjusted so that the above equation (5) holds true. As a result, vibrations caused by the oscillating rotation of the intermediate component 4 can be suppressed more effectively.

[0176] Implementation method 5.

[0177] Figure 23 This is a cross-sectional view showing the wheel device of embodiment 5. It should be noted that... Figure 23 It is the same as in implementation method 1 Figure 2 The corresponding diagram shows that the main motor 33 has a stator 332 and an annular rotor 331 surrounding the outer periphery of the stator 332. Therefore, the main motor 33 is an external rotor type motor. The axes of the rotor 331 and the stator 332 are aligned with the axis of the main motor 3.

[0178] The stator 332 is fixed to the fixed frame 31. The rotor 331 is mounted to the fixed frame 31 via a bearing 305. A rotating frame 34 is fixed to the rotor 331. The rotating frame 34 is mounted to the stator 332 via a bearing 306 embedded in a through hole 343. Thus, the rotating frame 34 can rotate integrally with the rotor 331 about the axis of the main body 3, relative to the stator 332 and the fixed frame 31.

[0179] The vibration damping structure 7 is positioned on the outer side of the rotating frame 34 in the width direction of the vehicle body, that is, on the negative side of the rotating frame 34 in the Y-axis direction. In addition, the vibration damping structure 7 is supported on the stator 332 through the through hole 343 of the rotating frame 34.

[0180] The vibration damping structure 7 includes a counterweight 71 and a speed-changing mechanism 72. The counterweight 71 is mounted on the rotating frame 34 via the speed-changing mechanism 72. The speed-changing mechanism 72 transmits the torque of the main motor 33 to the counterweight 71, so that the rotational speed of the counterweight 71 is twice the rotational speed of the rotor 331. The structure of the speed-changing mechanism 72 is the same as that of the planetary gear mechanism in Embodiment 2. That is, the speed-changing mechanism 72 has a sun gear 721, an internal gear 722, and a plurality of planetary gears 723.

[0181] The sun gear 721 and the internal gear 722 are coaxially arranged with the axis of the main body 3. The sun gear 721 is fixed to the stator 332. The internal gear 722 is an annular gear surrounding the sun gear 721.

[0182] Each planetary gear 723 is disposed between the sun gear 721 and the internal gear 722. Each planetary gear 723 meshes with both the sun gear 721 and the internal gear 722. Furthermore, each planetary gear 723 is mounted on the rotating frame 34. The internal gear 722 is supported by each planetary gear 723. The rotating frame 34 rotates integrally with the rotor 331, thereby causing each planetary gear 723 to revolve around the sun gear 721 about the axis of the main body 3. Therefore, the revolution speed of each planetary gear 723 relative to the sun gear 721 is the same as the rotational speed of the rotor 331. The internal gear 722 rotates about the axis of the main body 3 relative to the sun gear 721 while synchronizing with the revolution speed of each planetary gear 723 relative to the sun gear 721. Therefore, the transmission mechanism 72 of this embodiment is a sun-type planetary gear mechanism that takes the revolution force of each planetary gear 723 as input and the rotational force of the internal gear 722 as output.

[0183] Each planetary gear 723 has a gear shaft 723a, a first gear portion 723b, and a second gear portion 723c. The axis of the gear shaft 723a is aligned with the axis of the planetary gear 723. The gear shaft 723a is arranged parallel to the axis of the main body 3. Furthermore, the gear shaft 723a is rotatably mounted on the rotating plate portion 342 of the rotating frame 34.

[0184] The first gear portion 723b and the second gear portion 723c are fixed to the gear shaft 723a. Thus, the first gear portion 723b is coaxially fixed to the second gear portion 723c. The gear shaft 723a, the first gear portion 723b, and the second gear portion 723c rotate integrally around the axis of the planetary gear 723. The first gear portion 723b and the second gear portion 723c are adjacent to each other along the axial direction of the gear shaft 723a.

[0185] The first gear section 723b meshes with the internal gear 722. The second gear section 723c meshes with the sun gear 721. The number of teeth in the first gear section 723b and the number of teeth in the second gear section 723c are different. In this embodiment, the first gear section 723b has more teeth than the second gear section 723c.

[0186] The second gear portion 723c is located closer to the rotating frame 34 than the first gear portion 723b, that is, on the positive side of the first gear portion 723b in the Y-axis direction. It should be noted that the second gear portion 723c can also be located further away from the rotating frame 34 than the first gear portion 723b, that is, on the negative side of the first gear portion 723b in the Y-axis direction.

[0187] Using the number of teeth z1 of the sun gear 721, the number of teeth z2 of the internal gear 722, the number of teeth z3 of the first gear section 723b, and the number of teeth z4 of the second gear section 723c, the speed transmission ratio i of the speed change mechanism 72, which is a sun-type planetary gear mechanism, is expressed by the following formula (6).

[0188] i = (z1 / z2)·(z3 / z4)+1…(6)

[0189] In the transmission mechanism 72, the number of teeth of the sun gear 721, the internal gear 722, the first gear section 723b, and the second gear section 723c is determined such that the rotational speed of the internal gear 722 is twice the rotational speed of the rotor 331. That is, in the transmission mechanism 72, the number of teeth of the sun gear 721, the internal gear 722, the first gear section 723b, and the second gear section 723c is determined such that the speed transmission ratio i of the internal gear 722 relative to the rotational speed of the rotor 331 is 2. Therefore, when the rotor 331 rotates one revolution, the internal gear 722 rotates two revolutions in the same direction as the rotation of the rotor 331.

[0190] The counterweight 71 is fixed to the internal gear 722. Therefore, the counterweight 71 and the internal gear 722 rotate as a unit. Consequently, the rotation center line of the counterweight 71 is aligned with the axis of the main body 3. Furthermore, the position of the center of gravity 71a of the counterweight 71 is set at a position away from the rotation center line of the counterweight 71 in a direction orthogonal to it. In this embodiment, the position of the center of gravity 71a of the counterweight 71 is set at a position away from the rotation center line of the counterweight 71 in a direction along a second imaginary straight line. The center of gravity 71a of the counterweight 71 moves along a circle centered on the rotation center line of the counterweight 71 as the counterweight 71 rotates.

[0191] The wheel assembly 1 is configured such that, when the direction along the second imaginary straight line is aligned with the Z-axis direction, the center of gravity 71a of the counterweight 71 is located on the negative side of the Z-axis direction compared to the rotation center line of the counterweight 71. Therefore, in the wheel assembly 1, when the direction along the second imaginary straight line is aligned with the vertical direction, the center of gravity 71a of the counterweight 71 is located below the rotation center line of the counterweight 71. The other structures in Embodiment 5 are the same as in Embodiment 1.

[0192] In this wheel assembly 1, the torque of the main motor 33 is transmitted to the counterweight 71 via the speed change mechanism 72, so that the rotational speed of the counterweight 71 is twice the rotational speed of the rotor 331. Therefore, similarly to embodiment 3, it is possible to more reliably make the rotational speed of the counterweight 71 twice the rotational speed of the rotating frame 34. In addition, it is also possible to miniaturize the speed change mechanism 72.

[0193] Furthermore, the main motor 33 is an external rotor type motor, and the speed change mechanism 72 is a sun-type planetary gear mechanism. Therefore, the number of moving parts in the wheel assembly 1 can be reduced. Consequently, the occurrence of malfunctions in the wheel assembly 1 can be more reliably suppressed, further improving the reliability of the wheel assembly 1.

[0194] Implementation method 6.

[0195] Figure 24 This is a cross-sectional view showing the wheel device of embodiment 6. It should be noted that... Figure 24 It is the same as in implementation method 1 Figure 2 The corresponding figure shows that the vibration damping structure 7 is disposed on the rotating frame 34, which rotates integrally with the rotor 331. Furthermore, the vibration damping structure 7 is positioned on the outer side of the rotating frame 34 in the width direction of the vehicle body, specifically on the negative side in the Y-axis direction. The vibration damping structure 7 includes a counterweight 71 and a vibration damping motor 73. In this embodiment, the vibration damping structure 7 does not have a speed change mechanism.

[0196] The vibration damping motor 73 is a different motor from the main motor 33. The axis of the vibration damping motor 73 is aligned with the axis of the main body 3. The vibration damping motor 73 generates torque that rotates the counterweight 71. The vibration damping motor 73 has a counterweight drive unit 731 and a counterweight drive shaft 732.

[0197] The counterweight drive unit 731 is fixed to the rotating frame 34. Thus, the counterweight drive unit 731 rotates integrally with the rotating frame 34 about the axis of the main body 3.

[0198] The counterweight drive shaft 732 is rotatably mounted on the counterweight drive unit 731. Furthermore, the axis of the counterweight drive shaft 732 is aligned with the axis of the main body 3. By supplying power to the counterweight drive unit 731, the counterweight drive shaft 732 rotates relative to the counterweight drive unit 731 about the axis of the main body 3.

[0199] The main motor 33 and the vibration damping motor 73 are each controlled by a control device (not shown). The control device controls the main motor 33 and the vibration damping motor 73 respectively, so that the rotational speed of the counterweight drive shaft 732 relative to the counterweight drive unit 731 is the same as the rotational speed of the rotor 331 relative to the stator 332. Furthermore, the control device controls the main motor 33 and the vibration damping motor 73 respectively, so that the rotational direction of the counterweight drive shaft 732 and the rotational direction of the rotor 331 are the same. Therefore, viewed from the fixed frame 31 and the stator 332, the counterweight drive shaft 732 rotates at twice the rotational speed of the rotating frame 34 in the same direction as the rotational frame 34.

[0200] The counterweight 71 is fixed to the counterweight drive shaft 732. Therefore, the counterweight 71 rotates integrally with the counterweight drive shaft 732 about the axis of the main body 3. The rotational center line of the counterweight 71 coincides with the axis of the main body 3. Furthermore, the rotational speed of the counterweight 71 is the same as the rotational speed of the counterweight drive shaft 732. Thus, viewed from the fixed frame 31 and the stator 332, the counterweight 71 rotates at twice the rotational speed of the rotating frame 34 in the same direction as the rotation of the rotating frame 34.

[0201] The structure of the counterweight 71 is the same as that of the counterweight 71 in Embodiment 1. Therefore, the position of the center of gravity 71a of the counterweight 71 is set at a position away from the center line of rotation of the counterweight 71 in a direction orthogonal to the center line of rotation of the counterweight 71. In this embodiment, the position of the center of gravity 71a of the counterweight 71 is set at a position away from the center line of rotation of the counterweight 71 in a direction along the second imaginary straight line. The center of gravity 71a of the counterweight 71 moves along a circle centered on the center line of rotation of the counterweight 71 as the counterweight 71 rotates.

[0202] The wheel assembly 1 is configured such that, when the direction along the second imaginary straight line is aligned with the Z-axis direction, the center of gravity 71a of the counterweight 71 is located on the negative side of the Z-axis direction compared to the rotation center line of the counterweight 71. Therefore, in the wheel assembly 1, when the direction along the second imaginary straight line is aligned with the vertical direction, the center of gravity 71a of the counterweight 71 is located below the rotation center line of the counterweight 71. The other structures in Embodiment 6 are the same as in Embodiment 3.

[0203] In this wheel assembly 1, a vibration damping motor 73 that generates the torque to rotate the counterweight 71 is mounted on the rotating frame 34. Therefore, a transmission mechanism is not required, simplifying the structure of the wheel assembly 1. Consequently, the occurrence of malfunctions in the wheel assembly 1 can be more reliably suppressed, improving its reliability.

[0204] It should be noted that in embodiment 6, the vibration damping structure 7 is provided on the rotating frame 34. However, the vibration damping structure 7 may also be provided on the main shaft 32, which rotates integrally with the rotor 331. In this case, the counterweight drive unit 731 of the vibration damping motor 73 is fixed to the main shaft 32. In addition, in this case, the vibration damping structure 7 may be provided at either the first end 321 or the second end 322 of the main shaft 32. When the vibration damping structure 7 is provided at the second end 322 of the main shaft 32, the main shaft 32 is disposed through the rotating plate portion 342 of the rotating frame 34.

[0205] Implementation method 7.

[0206] Figure 25 This is a cross-sectional view showing the wheel assembly of embodiment 7. It should be noted that... Figure 25 It is the same as in implementation method 1 Figure 2 The corresponding diagram shows that the main motor 33, like in embodiment 5, is an external rotor type motor. The vibration damping structure 7 is positioned on the outer side of the rotating frame 34 in the width direction of the vehicle body, that is, on the negative side of the rotating frame 34 in the Y-axis direction. Furthermore, the vibration damping structure 7 is supported on the stator 332 through the through hole 343 of the rotating frame 34.

[0207] The structure of the vibration damping structure 7 is the same as that of the vibration damping structure 7 in embodiment 6. In the vibration damping structure 7, a vibration damping motor 73 that generates torque to rotate the counterweight 71 is provided on the stator 332. The axis of the vibration damping motor 73 is aligned with the axis of the main body 3. The counterweight drive unit 731 of the vibration damping motor 73 is fixed to the stator 332 through the through hole 343 of the rotating frame 34. By supplying power to the counterweight drive unit 731, the counterweight drive shaft 732 of the vibration damping motor 73 rotates relative to the counterweight drive unit 731 about the axis of the main body 3.

[0208] The main motor 33 and the vibration damping motor 73 are each controlled by a control device (not shown). The control device controls the main motor 33 and the vibration damping motor 73 respectively, such that the rotational speed of the counterweight drive shaft 732 relative to the counterweight drive unit 731 is twice the rotational speed of the rotor 331 relative to the stator 332. Furthermore, the control device controls the main motor 33 and the vibration damping motor 73 respectively, such that the rotational direction of the counterweight drive shaft 732 and the rotational direction of the rotor 331 are the same. Therefore, the counterweight drive shaft 732 rotates at twice the rotational speed of the rotating frame 34 in the same direction as the rotational direction of the rotating frame 34.

[0209] The counterweight 71 is fixed to the counterweight drive shaft 732. Thus, the counterweight 71 rotates integrally with the counterweight drive shaft 732 about the axis of the main body 3. Therefore, the counterweight 71 rotates at twice the rotational speed of the rotating frame 34 in the same direction as the rotation of the rotating frame 34.

[0210] The structure of the counterweight 71 is the same as that of the counterweight 71 in Embodiment 6. Therefore, the position of the center of gravity 71a of the counterweight 71 is set at a position away from the center line of rotation of the counterweight 71 in a direction orthogonal to the center line of rotation of the counterweight 71. In this embodiment, the position of the center of gravity 71a of the counterweight 71 is set at a position away from the center line of rotation of the counterweight 71 in a direction along the second imaginary straight line. The center of gravity 71a of the counterweight 71 moves along a circle centered on the center line of rotation of the counterweight 71 as the counterweight 71 rotates.

[0211] The wheel assembly 1 is configured such that, when the direction along the second imaginary straight line is aligned with the Z-axis direction, the center of gravity 71a of the counterweight 71 is located on the negative side of the Z-axis direction compared to the rotation center line of the counterweight 71. Therefore, in the wheel assembly 1, when the direction along the second imaginary straight line is aligned with the vertical direction, the center of gravity 71a of the counterweight 71 is located below the rotation center line of the counterweight 71. The other structures in Embodiment 7 are the same as in Embodiment 5.

[0212] In this wheel assembly 1, a vibration damping motor 73 that generates the torque to rotate the counterweight 71 is installed in the stator 332. Therefore, a transmission mechanism is not required, simplifying the structure of the wheel assembly 1. Consequently, the occurrence of malfunctions in the wheel assembly 1 can be suppressed more reliably, thus improving the reliability of the wheel assembly 1.

[0213] It should be noted that in embodiment 7, the vibration damping structure 7 is provided on the stator 332. However, the vibration damping structure 7 may also be provided on the fixed frame 31. In this case, the vibration damping structure 7 is positioned inside the vehicle body in the width direction, closer to the fixed frame 31. In addition, in this case, the counterweight drive unit 731 of the vibration damping motor 73 is fixed to the fixed frame 31.

[0214] Furthermore, in Embodiment 4, the counterweight 71, which allows for adjustment of the position of the center of gravity 71a, is applied to the counterweight 71 of the vibration damping structure 7 in Embodiment 1. However, the counterweight 71 of Embodiment 4, which allows for adjustment of the position of the center of gravity 71a, may also be applied to the counterweight 71 of the vibration damping structure 7 in Embodiments 2, 3, 6, and 7.

[0215] Furthermore, in each of the above embodiments, the rotation center line of the counterweight 71 is aligned with the axis of the main body 3. However, the rotation center line of the counterweight 71 may also deviate from the axis of the main body 3. Even so, the centrifugal force of the counterweight 71 can be used to counteract at least a portion of the excitation force caused by the oscillating rotation of the intermediate component 4, thereby suppressing the overall vibration of the wheel assembly 1.

[0216] Furthermore, in each of the above embodiments, the second imaginary line is orthogonal to the first imaginary line. However, the second imaginary line may not be orthogonal to the first imaginary line, as long as it is orthogonal to the axis of the intermediate component 4 and different from the first imaginary line.

[0217] Furthermore, in each of the above embodiments, the wheel rim 2 is made of metal such as iron. However, the wheel rim 2 may also be made of an elastic material such as rubber. When the wheel rim 2 is made of only metal, for example, in order to detect vehicles on the track, electricity may be intentionally supplied to the wheel assembly 1.

[0218] Furthermore, in each of the above embodiments, the wheel assembly 1 is applied to railway vehicles. However, the wheel assembly 1 can be applied to various vehicles or mobile devices such as automobiles, motorized two-wheelers, and elevators.

[0219] Explanation of reference numerals in the attached figures

[0220] 1. Wheel assembly, 2. Wheel rim, 3. Main body, 4. Intermediate component, 7. Vibration damping structure, 33. Main motor, 34. Rotating frame (main rotating part), 35. Transmission mechanism, 51. First elastic plate (first elastic body), 61. Second elastic plate (second elastic body), 71. Counterweight, 71a. Center of gravity, 72. Transmission mechanism, 73. Vibration damping motor, 331. Rotor, 332. Stator, 351 and 721. Sun gear, 352 and 722. Internal gear, 353 and 723. Planetary gear.

Claims

1. A wheel assembly, wherein, The wheel assembly includes: The main body has a rotatable rotating part; A ring-shaped intermediate component that surrounds the rotating part of the main body; A ring-shaped rim that surrounds the central component; A first elastic body connects the intermediate component and the wheel rim in such a way that the intermediate component can move relative to the wheel rim along a first imaginary straight line orthogonal to the axis of the intermediate component; The second elastic body connects the intermediate component and the rotating part of the main body in such a way that the intermediate component can move relative to the main body along a second imaginary line orthogonal to the axis of the intermediate component and intersecting the first imaginary line; A vibration damping structure, wherein the vibration damping structure is disposed on the main body and has a counterweight; and A speed-changing mechanism that causes the counterweight to rotate at twice the speed of the main rotating part in the same direction as the rotation of the main rotating part. The position of the center of gravity of the counterweight moves along a circle centered on the rotational centerline of the counterweight as the counterweight rotates. When the direction along the second imaginary straight line is consistent with the vertical direction, the position of the center of gravity of the counterweight becomes a position lower than the rotation center line of the counterweight.

2. The wheel assembly as claimed in claim 1, wherein, The counterweight can be adjusted to the distance from the center line of rotation of the counterweight to the center of gravity of the counterweight.

3. The wheel assembly as claimed in claim 1, wherein, The product of the distance from the center line of rotation of the counterweight to the center of gravity of the counterweight and the mass of the counterweight is equal to 1 / 4 of the product of the vertical displacement of the intermediate component during the rotation of the rim and the mass of the intermediate component.

4. The wheel assembly as claimed in claim 1, wherein, The main body has a main motor that generates torque to rotate the rotating part of the main body.

5. The wheel assembly as claimed in claim 4, wherein, The main motor has a stator and a rotor that rotates relative to the stator. The counterweight rotates integrally with the rotor. The speed-changing mechanism transmits the torque of the main motor to the main rotating part, so that the rotational speed of the counterweight is twice the rotational speed of the main rotating part.

6. The wheel assembly as claimed in claim 4, wherein, The main motor has a stator and a rotor that rotates relative to the stator. The main rotating part rotates integrally with the rotor. The speed-changing mechanism transmits the torque of the main motor to the counterweight, so that the rotational speed of the counterweight is twice the rotational speed of the rotor.

7. The wheel assembly as claimed in claim 5 or 6, wherein, The transmission mechanism has a sun gear, an annular internal gear surrounding the sun gear, and planetary gears disposed between the sun gear and the internal gear. The planetary gear has a first gear portion that meshes with the internal gear and a second gear portion that meshes with the sun gear. The first gear is coaxially fixed to the second gear. The planetary gears as a whole have a gear ratio of 2.

8. A wheel assembly, wherein, The wheel assembly includes: The main body has a rotatable rotating part; A ring-shaped intermediate component that surrounds the rotating part of the main body; A ring-shaped rim that surrounds the central component; A first elastic body connects the intermediate component and the wheel rim in such a way that the intermediate component can move relative to the wheel rim along a first imaginary straight line orthogonal to the axis of the intermediate component; The second elastic body connects the intermediate component and the rotating part of the main body in such a way that the intermediate component can move relative to the main body along a second imaginary line orthogonal to the axis of the intermediate component and intersecting the first imaginary line; A vibration damping structure is disposed on the main body and has a counterweight; as well as A vibration damping motor generates a torque that causes the counterweight to rotate at twice the rotational speed of the main rotating part in the same direction as the rotational direction of the main rotating part. The position of the center of gravity of the counterweight moves along a circle centered on the rotational centerline of the counterweight as the counterweight rotates. When the direction along the second imaginary straight line is consistent with the vertical direction, the position of the center of gravity of the counterweight becomes a position lower than the rotation center line of the counterweight.

9. The wheel assembly as claimed in claim 8, wherein, The counterweight can be adjusted to the distance from the center line of rotation of the counterweight to the center of gravity of the counterweight.

10. The wheel assembly as claimed in claim 8 or 9, wherein, The product of the distance from the center line of rotation of the counterweight to the center of gravity of the counterweight and the mass of the counterweight is equal to 1 / 4 of the product of the vertical displacement of the intermediate component during the rotation of the rim and the mass of the intermediate component.

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