Bed apparatus

Abstract

The present invention is a bed apparatus (1). The bed apparatus (1) comprises a bed part (4) and a tilting part (3) that tilts the bed part (4). The tilting part (3) comprises a supporting-point part (10) that supports the bed part (4) via a spherical bearing, a first driving apparatus (20) that rotates the bed part (4) about a roll axis (r) with the supporting-point part (10) at the center, and a second driving apparatus (30) that rotates the bed part (4) about a pitch axis (p) with the supporting-point part (10) at the center. The supporting-point part (10), the first driving apparatus (20), and the second driving apparatus (30) are disposed on a central axis line (O1) passing through the width-direction center of the bed part (4).

Description

Bed device

[0001] This application claims priority to Japanese Patent Application No. 2024-134554, filed on August 9, 2024, the contents of which are incorporated herein by reference.

[0002] Patent Document 1 below discloses a medical robot system. This medical robot system includes a station, a surgical robot having at least one arm unit provided on the station and having a medical instrument attached to its tip, the medical instrument provided on the tip of the arm unit, and a movable bed installed on the station and capable of changing its position and orientation on the station.

[0003] Japanese Patent Application Publication No. 2012-5557

[0004] The adjustable bed is rotatable by a bed motion drive unit around an axis extending in the longitudinal direction (around the roll axis) and around an axis extending in the width direction (around the pitch axis) (see FIG. 5 of Patent Document 1). This bed motion drive unit tilts the entire adjustable bed. As a result, the bed motion drive unit has a very large device configuration, and requires a large installation space below the bed.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to provide a bed device that can rotate a bed portion around a roll axis and a pitch axis with a compact device configuration.

[0006] In order to solve the above-mentioned problems, a first aspect of the present invention is a bed device comprising a bed section and a tilting section that tilts the bed section, wherein the tilting section comprises a fulcrum section that supports the bed section via a spherical bearing, a first drive unit that rotates the bed section around a roll axis centered on the fulcrum section, and a second drive unit that rotates the bed section around a pitch axis centered on the fulcrum section, and the fulcrum section, the first drive unit, and the second drive unit are arranged on a central axis that passes through the center of the width of the bed section.

[0007] A second aspect of the present invention is the bed apparatus according to the first aspect, wherein the tilting section supports one end side of the bed section in a cantilever manner in the longitudinal direction.

[0008] A third aspect of the present invention is the bed device of the second aspect, in which the fulcrum portion, the first drive device, and the second drive device are arranged in this order from the other end side of the longitudinal direction of the bed portion toward the one end side.

[0009] A fourth aspect of the present invention is a bed device according to any one of the first to third aspects, wherein the first drive device comprises a first connecting member connected to the bed portion, the second drive device comprises a second connecting member connected to the bed portion, and the fulcrum portion, the first connecting member, and the second connecting member are arranged on the central axis of the bed portion.

[0010] A fifth aspect of the present invention is the bed apparatus of the fourth aspect, wherein the first drive device comprises: a first link mechanism coupled to the first connecting member and following at least the rotation of the bed section around the pitch axis; and a first linear guide device that guides the first connecting member in the width direction of the bed section via the first link mechanism.

[0011] A sixth aspect of the present invention is the bed device of the fifth aspect, wherein the first linear guide device comprises a track body extending in the width direction, a moving body moving along the track body, and a plurality of rolling bodies interposed between the track body and the moving body.

[0012] A seventh aspect of the present invention is the bed device of the fifth aspect, wherein the first link mechanism comprises a first arm portion extending in the width direction, a first connecting portion that connects one end of the first arm portion in the width direction to the first connecting member via a spherical bearing, and a second connecting portion that connects the other end of the first arm portion in the width direction to the first linear guide device via a spherical bearing, and the first drive device comprises an arm attitude control device that returns the first arm portion to its original attitude when the first arm portion rotates around an axis parallel to the pitch axis.

[0013] An eighth aspect of the present invention is the bed device of the fourth aspect, wherein the second drive device comprises a second link mechanism connected to the second connecting member and following at least the rotation of the bed section around the roll axis, and a second linear guide device that guides the second connecting member in the height direction of the bed section via the second link mechanism.

[0014] A ninth aspect of the present invention is the bed device of the eighth aspect, wherein the second linear guide device comprises a track body extending in the height direction, a moving body moving along the track body, and a plurality of rolling bodies interposed between the track body and the moving body.

[0015] A tenth aspect of the present invention is the bed device of the eighth aspect, wherein the second link mechanism comprises a second arm portion extending in the height direction, a third connecting portion that connects one end of the second arm portion in the height direction to the second connecting member via a spherical bearing, and a fourth connecting portion that connects the other end of the second arm portion in the height direction to the second linear guide device rotatably around an axis parallel to the pitch axis.

[0016] According to the present invention, the bed section can be rotated around the roll axis and the pitch axis with a compact device configuration.

[0017] FIG. 7 is a side view of a bed apparatus according to an embodiment. FIG. 8 is a plan view of a bed apparatus according to an embodiment. FIG. 9 is a perspective view of a tilting unit according to an embodiment. FIG. 10 is an exploded perspective view of a tilting unit according to an embodiment. FIG. 11 is a bottom perspective view of a table member according to an embodiment. FIG. 12 is a plan view of a tilting unit with the table member removed according to an embodiment. FIG. 13 is a cross-sectional view taken along line VII-VII shown in FIG. 6. FIG. 14 is a perspective view of a first drive unit according to an embodiment. FIG. 15 is an exploded perspective view of a first drive unit according to an embodiment. FIG. 16 is a half cross-sectional view of a linear guide according to an embodiment. FIG. 17 is a perspective view of a second drive unit according to an embodiment. FIG. 18 is an exploded perspective view of a second drive unit according to an embodiment.

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0019] Fig. 1 is a side view of a bed apparatus 1 according to one embodiment. Fig. 2 is a plan view of the bed apparatus 1 according to one embodiment. As shown in Fig. 1, the bed apparatus 1 includes a base portion 2, a tilting portion 3 (tilting device), and a bed portion 4.

[0020] The bed apparatus 1 of this embodiment constitutes a part of a radiotherapy robot system that treats an affected area of ​​a patient H with, for example, X-rays or heavy particle beams. The bed section 4 supports the patient H in a supine position. As shown in Fig. 2, the bed section 4 has a rectangular shape in a plan view. Note that the shape of the bed section 4 is not limited to a rectangular shape in a plan view, and may have a curved surface at, for example, one end 4a or the other end 4b in the longitudinal direction.

[0021] In the following description, an XYZ Cartesian coordinate system is set, and the positional relationships of the various components are sometimes described with reference to this XYZ Cartesian coordinate system. The X-axis direction is the longitudinal direction when the bed 4 is supported horizontally. The Y-axis direction is the width direction (short direction) when the bed 4 is supported horizontally. The Z-axis direction is the height direction (thickness direction) when the bed 4 is supported horizontally.

[0022] 1, the base unit 2 supports the bed unit 4 via a tilting unit 3. The base unit 2 supports the bed unit 4 so that it can move in at least one of the X-axis, Y-axis, and Z-axis directions. The base unit 2 is configured, for example, by an automated guided vehicle (AGV) with a lifting function or an articulated robot.

[0023] 2, the tilting unit 3 cantilevers one end 4a of the bed 4 in the longitudinal direction (X-axis direction). In other words, the other end 4b of the bed 4 in the longitudinal direction is a free end. The tilting unit 3 includes a fulcrum 10 that supports the bed 4 via a spherical bearing 12 (described later), a first drive unit 20 that rotates the bed 4 about the roll axis r around the fulcrum 10, and a second drive unit 30 that rotates the bed 4 about the pitch axis p around the fulcrum 10.

[0024] The roll axis r passes through the fulcrum 10 and extends in the X-axis direction. In a plan view, the roll axis r coincides with a central axis O1 that passes through the center of the bed 4 in the width direction (Y-axis direction). The first driving device 20 rotates the bed 4 around the roll axis r by moving a first connecting member 21 connected to the bed 4 in the width direction (Y-axis direction). The direction of rotation around the roll axis r is referred to as the θX direction.

[0025] The pitch axis p passes through the fulcrum 10 and extends in the Y-axis direction. In a plan view, the pitch axis p coincides with an axis O2 at the fulcrum 10 that is perpendicular to the central axis O1. The second drive unit 30 rotates the bed 4 around the pitch axis p by moving a second connecting member 31 connected to the bed 4 in the height direction (Z-axis direction). The direction of rotation around the pitch axis p is referred to as the θY direction.

[0026] Although the tilting section 3 of this embodiment does not include a drive device for rotating the bed section 4 around the yaw axis y (axis O3), it may include such a drive device.

[0027] 2, the fulcrum 10, the first driving device 20, and the second driving device 30 are disposed on the central axis O1 (roll axis r) of the bed 4. Specifically, the fulcrum 10, the first connecting member 21 of the first driving device 20, and the second connecting member 31 of the second driving device 30 are connected to the bed 4 and disposed on the central axis O1 of the bed 4.

[0028] The fulcrum 10, first drive device 20, and second drive device 30 are arranged in this order from the other longitudinal end 4b of the bed 4 toward the one longitudinal end 4a. In other words, the second drive device 30 is arranged farther from the fulcrum 10 than the first drive device 20. For example, as shown in FIG. 1 , when the bed 4 supports the patient H, a lifting load in the Z-axis direction acts on the second drive device 30. By increasing the distance between the fulcrum 10 and the second drive device 30, the lifting load in the Z-axis direction can be reduced. This allows the size of the components of the second drive device 30, which will be described later, to be reduced, thereby achieving a lighter and more compact tilting unit 3. Note that the bed 4 can still be tilted even if the order of the fulcrum 10, first drive device 20, and second drive device 30 is reversed.

[0029] Fig. 3 is a perspective view of the tilting unit 3 according to one embodiment. Fig. 4 is an exploded perspective view of the tilting unit 3 according to one embodiment. As shown in these figures, the tilting unit 3 includes a fulcrum unit 10, a first driving device 20, a second driving device 30, a base member 40, and a table member 50.

[0030] The base member 40 has a flat plate shape extending along the XY plane. A fulcrum portion 10, a first drive unit 20, and a second drive unit 30 are provided on the upper surface of the base member 40. The table member 50 is supported by the fulcrum portion 10, the first drive unit 20, and the second drive unit 30. The table member 50 faces the base member 40 in the Z-axis direction.

[0031] In this embodiment, the outer shape of the table member 50 matches the outer shape of the base member 40. However, the outer shape of the table member 50 does not have to match the outer shape of the base member 40. The table member 50 is connected to the bed portion 4. However, the table member 50 itself may be the bed portion 4. In this case, the bed portion 4 is supported by the fulcrum portion 10, the first drive unit 20, and the second drive unit 30.

[0032] As shown in Figure 4, the fulcrum 10 is disposed at the end on the +X side of the base member 40. The fulcrum 10 stands on the +Z side from the upper surface of the base member 40. A through hole 11 that passes through in the X-axis direction is formed at the upper end of the fulcrum 10. An outer ring 12a of a spherical bearing 12 is attached to the through hole 11. The spherical bearing 12 is also called a spherical plain bearing.

[0033] Figure 5 is a bottom perspective view of a table member 50 according to one embodiment. As shown in Figure 5, the inner ring 12b of the spherical bearing 12 is attached to the underside of the table member 50. The underside of the table member 50 is provided with a first upright portion 51 and a second upright portion 52 that hang down from the -Z side of the underside of the table member 50, and a shaft portion 53 whose both ends are supported by the first upright portion 51 and the second upright portion 52.

[0034] The first upright portion 51 and the second upright portion 52 are arranged to be spaced apart in the X-axis direction. The first upright portion 51 is slightly larger than the second upright portion 52, but may be the same size as the second upright portion 52. The shaft portion 53 extends in the X-axis direction. The inner ring 12b is attached to the shaft portion 53. By engaging the inner ring 12b with the outer ring 12a, the table member 50 can rotate around the roll axis r and the pitch axis p, which are centered on the fulcrum portion 10 (spherical bearing 12).

[0035] Figure 6 is a plan view of the tilting unit 3 with the table member 50 removed according to one embodiment. Figure 7 is a cross-sectional view taken along line VII-VII in Figure 6. As shown in Figure 6, the first driving unit 20 is disposed on the -X side of the fulcrum unit 10. The second driving unit 30 is disposed further to the -X side of the first driving unit 20.

[0036] The first drive device 20 includes a first connecting member 21 connected to the table member 50, a first link mechanism 22 coupled to the first connecting member 21 and following at least the rotation of the table member 50 around the pitch axis p, and a first linear guide device 23 that guides the first connecting member 21 in a first direction (Y-axis direction) parallel to the pitch axis p via the first link mechanism 22.

[0037] The second drive device 30 also includes a second connecting member 31 connected to the table member 50, a second link mechanism 32 (see Figures 3 and 7) connected to the second connecting member 31 and following at least the rotation of the table member 50 around the roll axis r, and a second linear guide device 33 that guides the second connecting member 31 via the second link mechanism 32 in a second direction (Z-axis direction) perpendicular to the pitch axis p and the roll axis r.

[0038] Fig. 8 is a perspective view of the first drive unit 20 according to one embodiment. Fig. 9 is an exploded perspective view of the first drive unit 20 according to one embodiment. As shown in Fig. 8, the first drive unit 20 includes a first connecting member 21, a first link mechanism 22, a first linear guide device 23, and a worm gear unit 24. The first drive unit 20 also includes a first mounting plate 200 that is attached to the base member 40.

[0039] 9 , the first connecting member 21 has a block-shaped connecting body 210. A first mounting hole 211 and a second mounting hole 212 are provided on the top surface of the connecting body 210. The first mounting holes 211 are arranged in pairs with a gap in the X-axis direction. A positioning protrusion (not shown) is attached to the first mounting hole 211 to align the table member 50 and the connecting body 210.

[0040] The second mounting holes 212 are provided in two rows along two sides extending in the X-axis direction on the top surface of the connection portion main body 210. A pair of first mounting holes 211 is disposed between the two rows of second mounting holes 212. A fixing member such as a bolt (not shown) that fixes the connection portion main body 210 and the table member 50 is attached to the second mounting holes 212.

[0041] A pair of shaft supports 213 are vertically attached to the underside of the connection portion main body 210. The pair of shaft supports 213 are spaced apart in the X-axis direction. The pair of shaft supports 213 support both ends of a shaft portion 214 extending in the X-axis direction. An inner ring 224b of a spherical bearing 224 is attached to the shaft portion 214.

[0042] The first link mechanism 22 comprises a first arm portion 220 extending in the Y-axis direction, a first connecting portion 221 connecting one end of the first arm portion 220 in the Y-axis direction (the end on the +Y side) to the first connecting member 21 via a spherical bearing 224, and a second connecting portion 222 connecting the other end of the first arm portion 220 in the Y-axis direction (the end on the -Y side) to the first linear guide device 23 via a spherical bearing 226.

[0043] The first arm portion 220 is formed in a plate shape with its length direction in the Y-axis direction, its width direction in the Z-axis direction, and its thickness direction in the X-axis direction. A through-hole 223 that penetrates in the X-axis direction is formed at the end on the +Y side of the first arm portion 220. An outer ring 224a of a spherical bearing 224 is attached to the through-hole 223.

[0044] The inner ring 224b engages with the outer ring 224a, allowing the first connecting member 21 to rotate around the spherical bearing 224. Meanwhile, a through-hole 225 that penetrates in the X-axis direction is formed at the end on the -Y side of the first arm portion 220. An outer ring 226a of the spherical bearing 226 is attached to the through-hole 225.

[0045] The first linear guide device 23 includes a track body 231 and a moving body 232. The track body 231 is fixed to the first mounting plate 200 and includes a track rail 61 extending in the Y-axis direction. The moving body 232 includes a slider block 62 that moves in the Y-axis direction along the track rail 61. The track rail 61 and the slider block 62 configure a linear guide 60.

[0046] 10 is a half cross-sectional view of a linear guide 60 according to one embodiment. The linear guide 60 includes a track rail 61 having rolling element rolling grooves 63 formed along the longitudinal direction, a slider block 62 having loaded rolling element rolling grooves 64 facing the rolling element rolling grooves 63, and a plurality of balls 65 (rolling elements) arranged between the rolling element rolling grooves 63 and the loaded rolling element rolling grooves 64.

[0047] The track rail 61 is a long member having a generally rectangular cross section. On an outer surface 61b of the track rail 61 in the width direction (left-right direction on the paper in FIG. 10 ), rolling element rolling grooves 63 are formed along the longitudinal direction of the track rail 61 (direction perpendicular to the paper in FIG. 10 ). The rolling element rolling grooves 63 are recessed into the outer surface 61b in a generally arc-like shape. A pair of rolling element rolling grooves 63 are formed on the left and right sides of the track rail 61.

[0048] The track rail 61 is formed with fixing holes 66 (track body fixing holes) for fixing the track rail 61 to the first mounting plate 200 (see FIGS. 9 and 10 ). The fixing holes 66 are formed to penetrate the track rail 61 in the thickness direction (the vertical direction on the paper in FIG. 10 ). The fixing holes 66 are formed with counterbore holes 66 a for positioning bolts (not shown) that fix the track rail 61 to the first mounting plate 200 at a position lower than the upper surface 61 a of the track rail 61.

[0049] The slider block 62 includes a block body 67 and a cover body 68 attached to the block body 67. The block body 67 has a rail accommodating groove 69 that accommodates the track rail 61. The rail accommodating groove 69 opens to the lower surface of the block body 67. A fixing hole 70 (movable body fixing hole) for fixing an object (a movable block 233 described later) is formed in a mounting surface 67a, which is the upper surface of the block body 67. The fixing hole 70 is formed to a predetermined depth in the thickness direction of the block body 67. The fixing hole 70 is a screw hole into which a bolt (not shown) that fixes the object is screwed.

[0050] The rail accommodating groove 69 is formed with a loaded rolling element rolling groove 64 that faces the rolling element rolling groove 63 of the track rail 61. The loaded rolling element rolling groove 64 is recessed in an arc shape into the inner surface of the rail accommodating groove 69. A pair of loaded rolling element rolling grooves 64 are formed on the left and right sides of the slider block 62 so as to sandwich the track rail 61. The loaded rolling element rolling groove 64 faces the rolling element rolling groove 63 of the track rail 61 and forms a loaded rolling element rolling path C1 along which the balls 65 roll under load.

[0051] Furthermore, unloaded rolling member rolling paths C2 are formed in the block body 67. The unloaded rolling member rolling paths C2 are formed to penetrate the block body 67 in the longitudinal direction. The inner diameter of the unloaded rolling member rolling paths C2 is larger than the diameter of the balls 65 so as not to apply a load to the balls 65. A pair of unloaded rolling member rolling paths C2 are formed on the left and right sides of the slider block 62 in correspondence with the loaded rolling member rolling grooves 64 (loaded rolling member rolling paths C1).

[0052] The lid body 68 is attached to each of both longitudinal end faces of the block body 67. Like the block body 67, the lid body 68 has rail accommodating grooves 71 that accommodate the track rails 61. The lid body 68 has rolling element direction changing paths C3 formed on opposing surfaces that face each of the longitudinal end faces of the block body 67. The pair of rolling element direction changing paths C3 connect both ends of the loaded rolling element rolling path C1 and both ends of the unloaded rolling element rolling path C2, respectively, to form an endless circulation path C for the balls 65.

[0053] The endless circulation path C is composed of a pair of straight portions (loaded rolling element rolling path C1 and unloaded rolling element rolling path C2) extending in the longitudinal direction of the track rail 61, and a pair of semicircular curved portions (rolling element direction changing path C3) connecting the ends of the pair of straight portions. In this embodiment, two endless circulation paths C are formed so as to be spaced apart in the width direction of the track rail 61 and extend parallel to each other along the longitudinal direction of the track rail 61. Note that the linear guide 60 may be one in which two endless circulation paths C are formed on each side, i.e., one in which a total of four endless circulation paths C are formed. Alternatively, a finite stroke linear guide without the endless circulation paths C may be used as the linear guide 60. In this finite stroke linear guide, a cage (rolling element holding member) is arranged between the rolling element rolling grooves 63 and the loaded rolling element rolling grooves 64, and ball holders provided in the cage rotatably hold balls 65.

[0054] The balls 65 are interposed between the track rail 61 and the slider block 62 to allow the slider block 62 to move smoothly relative to the track rail 61. The balls 65 in this embodiment are arranged inside the endless circulation path C with almost no gaps between them, and circulate through the endless circulation path C.

[0055] 9, the movable body 232 includes a movable block 233 fixed to the slider block 62. A groove 233a is formed on the +Y side of the movable block 233, into which the -Y side end of the first arm unit 220 can be inserted. A shaft 234 extending in the X-axis direction is installed in the groove 233a. An inner ring 226b of the spherical bearing 226 is attached to the shaft 234.

[0056] The inner ring 226b engages with the outer ring 226a, allowing the first arm unit 220 to rotate around the spherical bearing 226. The first driving unit 20 includes an arm posture control device 25 for the first arm unit 220. As shown in Fig. 7 , a pair of arm posture control devices 25 are provided, sandwiching the shaft unit 234 in the Z-axis direction.

[0057] The arm attitude control device 25 includes a plunger 250 having a ball 251 and a spring 252, and a pressing screw 253 that presses the plunger 250 against the first arm portion 220. The plunger 250 is formed in a cylindrical shape with a closed bottom and an open tip on the +X side. A ball 251 is disposed at the tip of the plunger 250. The spring 252 is disposed inside the plunger 250 and urges the ball 251 toward the +X side.

[0058] The pressing screw 253 adjusts the pressing force (urging force) of the plunger 250 against the first arm portion 220. The arm posture control device 25 returns the first arm portion 220 to its original posture (a posture in which the plate surface of the first arm portion 220 is along the YZ plane) when the first arm portion 220 rotates around the axis O4 by the spherical bearing 226. This prevents the first arm portion 220 from contacting (colliding with) the movable block 233.

[0059] 9, a nut 235 is attached to the -Y side of the movable block 233. The nut 235 is threadedly engaged with a ball screw shaft 241 of the worm gear unit 24, and moves in the Y-axis direction together with the movable block 233. The worm gear unit 24 includes the ball screw shaft 241 and a gear box 242.

[0060] The ball screw shaft 241 extends in the Y-axis direction. Inside the gear box 242, there are provided a worm wheel (not shown) connected to the ball screw shaft 241 and a worm shaft (not shown) that meshes with the worm wheel. The worm shaft is connected to a rotating shaft of a motor (not shown) attached to a motor connection portion 243 of the gear box 242.

[0061] Fig. 11 is a perspective view of the second drive unit 30 according to one embodiment. Fig. 12 is an exploded perspective view of the second drive unit 30 according to one embodiment. As shown in Fig. 11 , the second drive unit 30 includes a second connecting member 31, a second link mechanism 32, a second linear guide device 33, and a worm gear unit 34. The second drive unit 30 also includes a second mounting plate 300 that is attached to the base member 40.

[0062] 12 , the second connecting member 31 has a plate-shaped connecting body 310. The upper surface of the connecting body 310 is provided with a positioning protrusion 311 and an attachment hole 312. The positioning protrusions 311 are arranged in pairs with a gap in the X-axis direction. The pair of positioning protrusions 311 positions the table member 50 and the connecting body 310.

[0063] The mounting holes 312 are provided in two rows along two sides extending in the X-axis direction on the top surface of the connection part main body 310. A pair of positioning protrusions 311 is disposed between the two rows of mounting holes 312. Fixing members such as bolts (not shown) that fix the connection part main body 310 and the table member 50 are attached to the mounting holes 312.

[0064] A pair of shaft supports 313 are vertically attached to the underside of the connection portion main body 310. The pair of shaft supports 313 are spaced apart in the X-axis direction. The pair of shaft supports 313 support both ends of a shaft portion 314 extending in the X-axis direction. An inner ring 324b of a spherical bearing 324 is attached to the shaft portion 314.

[0065] The second link mechanism 32 comprises a second arm portion 320 extending in the Z-axis direction, a third connecting portion 321 connecting one end of the second arm portion 320 in the Z-axis direction (the end on the +Z side) to the second connecting member 31 via a spherical bearing 324, and a fourth connecting portion 322 connecting the other end of the second arm portion 320 in the Z-axis direction (the end on the -Z side) to the second linear guide device 33 so as to be rotatable around an axis O7 (see Figure 7) parallel to the pitch axis p.

[0066] 12 , the second arm portion 320 is formed in a plate shape with its longitudinal direction in the Z-axis direction, its width direction in the Y-axis direction, and its thickness direction in the X-axis direction. A through-hole 323 that penetrates in the X-axis direction is formed at the end on the +Z side of the second arm portion 320. An outer ring 324a of a spherical bearing 324 is attached to the through-hole 323.

[0067] The inner ring 324b engages with the outer ring 324a, allowing the second connecting member 31 to rotate around the spherical bearing 324. Meanwhile, a thrust bush 325 is provided at the end of the second arm portion 320 on the -Z side. A pair of thrust bushes 325 are attached to both side surfaces of the second arm portion 320 facing the Y-axis direction. Note that a rolling bearing, a spherical bearing, or the like may be used instead of the thrust bush 325.

[0068] The second linear guide device 33 includes a track body 331 and a moving body 332. The track body 331 includes a plurality of track rails 61 extending in the Z-axis direction. The moving body 332 includes a plurality of slider blocks 62 that move in the Y-axis direction along the plurality of track rails 61. In this embodiment, four track rails 61 and four slider blocks 62 are provided. That is, the second linear guide device 33 includes four linear guides 60. The number of linear guides 60 is not limited and may be, for example, two (one opposing axis). Furthermore, a sliding guide may be adopted instead of the linear guide 60, and the same applies to the first drive device 20.

[0069] The second mounting plate 300 has a pair of rail support parts 301 that face each other in the Y-axis direction. Two track rails 61 are attached to each of the opposing surfaces of the pair of rail support parts 301 in the Y-axis direction. The two track rails 61 are spaced apart in the X-axis direction and extend parallel to each other in the Z-axis direction. The second mounting plate 300 has a recess 302 that accommodates the lower end of the track rail 61. By accommodating the lower end of the track rail 61 in the recess 302, the height dimension of the tilting section 3 can be reduced.

[0070] The movable body 332 includes a movable block 333. A through-hole 333a is formed in the movable block 333, penetrating in the Z-axis direction. A nut 334 is attached to the through-hole 333a. The nut 334 is threadedly engaged with a ball screw shaft 341 of the worm gear unit 34, and moves in the Z-axis direction together with the movable block 333. The worm gear unit 34 includes the ball screw shaft 341 and a gear box 342.

[0071] The ball screw shaft 341 extends in the Z-axis direction. Inside the gear box 342, there are provided a worm wheel (not shown) connected to the ball screw shaft 341 and a worm shaft (not shown) that meshes with the worm wheel. The worm shaft is connected to a rotating shaft of a motor (not shown) attached to a motor connection portion 343 of the gear box 342.

[0072] A pair of fixed plates 335 are fixed to the movable block 333. The pair of fixed plates 335 are arranged facing each other in the Y-axis direction. Two slider blocks 62 are attached to each of the surfaces of the pair of fixed plates 335 facing in the Y-axis direction and facing away from each other. The two slider blocks 62 are attached spaced apart in the X-axis direction.

[0073] A pair of shafts 336 protruding toward each other are provided on the opposing surfaces of the pair of fixed plates 335. When the pair of shafts 336 engage with the pair of thrust bushings 325, the second arm portion 320 becomes rotatable relative to the movable block 333 about an axis O7 (see FIG. 7) that is parallel to the pitch axis p.

[0074] 7 , for example, when the ball screw shaft 341 rotates in the second driving device 30, the movable block 333 is guided in the Z-axis direction by the second linear guide device 33, and the second connecting member 31 moves in the Z-axis direction via the second link mechanism 32. This causes the table member 50 to rotate around the pitch axis p around the fulcrum part 10. At this time, the first driving device 20 can follow the rotation of the table member 50 around the pitch axis p by the first link mechanism 22.

[0075] Furthermore, when the ball screw shaft 241 in the first driving device 20 rotates, the movable block 233 is guided in the Y-axis direction by the first linear guide device 23, and the first connecting member 21 moves in the Y-axis direction via the first link mechanism 22. This causes the table member 50 to rotate around the roll axis r, centered on the fulcrum part 10. At this time, the second driving device 30 can follow the rotation of the table member 50 around the roll axis r by means of the second link mechanism 32.

[0076] The tilting unit 3 is also capable of compound rotation including rotation around the roll axis r and the pitch axis p. At this time, the first drive unit 20 follows this compound tilting movement via the first link mechanism 22, and the second drive unit 30 follows this compound tilting movement via the second link mechanism 32. The first link mechanism 22 includes spherical bearings 224 and 226, and has a higher degree of freedom than the second link mechanism 32. However, the first drive unit 20 includes an arm posture control device 25. This allows the posture of the first arm unit 220 to be controlled so that it returns to its original posture.

[0077] As described above, the bed apparatus 1 of this embodiment includes the bed 4 and the tilting unit 3 that tilts the bed 4. The tilting unit 3 includes the fulcrum 10 that supports the bed 4 via a spherical bearing 12, the first drive unit 20 that rotates the bed 4 around the roll axis r around the fulcrum 10, and the second drive unit 30 that rotates the bed 4 around the pitch axis p around the fulcrum 10. As shown in FIG. 2 , the fulcrum 10, the first drive unit 20, and the second drive unit 30 are arranged on the central axis O1 that passes through the center of the width of the bed 4. This allows the width (Y-axis) dimension of the tilting unit 3 to be reduced. Furthermore, the function of rotating the bed 4 around the roll axis r and the function of rotating the bed 4 around the pitch axis p are separated and not integrated into a single device. This allows the height (Z-axis) dimension of the tilting unit 3 to be reduced, as shown in FIG. 7 .

[0078] Furthermore, in this embodiment, the tilting unit 3 cantilevers one end 4a of the bed 4 in the longitudinal direction (X-axis direction). With this configuration, the tilting unit 3 does not need to support the entire lower side of the bed 4 as in the prior art. This allows the size of the tilting unit 3 in the longitudinal direction (X-axis direction) to be reduced.

[0079] In addition, in this embodiment, the fulcrum portion 10, the first drive unit 20, and the second drive unit 30 are arranged in this order from the other end 4b toward the one end 4a in the longitudinal direction of the bed portion 4. With this configuration, the second drive unit 30 is arranged farther from the fulcrum portion 10 than the first drive unit 30. By increasing the distance between the fulcrum portion 10 and the second drive unit 30, the lifting load in the Z-axis direction can be reduced, and the size of the components of the second drive unit 30 (such as the linear guide 60) can be reduced. This allows the tilting portion 3 to be made lighter and more compact.

[0080] Furthermore, in this embodiment, the first driving device 20 includes a first connecting member 21 connected to the bed 4, and the second driving device 30 includes a second connecting member 31 connected to the bed 4, and the fulcrum 10, the first connecting member 21, and the second connecting member 31 are arranged on the central axis O1 of the bed 4. With this configuration, the fulcrum 10 supporting the bed 4, the connection position of the first driving device 20 with the bed 4 (the position where a force is applied in the Y-axis direction), and the connection position of the second driving device 30 with the bed 4 (the position where a force is applied in the Z-axis direction) are all aligned on the central axis O1 of the bed 4. This makes it easier to rotate the bed 4.

[0081] Furthermore, in this embodiment, the first drive unit 20 includes a first link mechanism 22 that is coupled to the first connecting member 21 and follows at least the rotation of the bed 4 about the pitch axis p, and a first linear guide device 23 that guides the first connecting member 21 in the width direction of the bed 4 via the first link mechanism 22. According to this configuration, the first connecting member 21 connected to the bed 4 is guided in the width direction (Y-axis direction) by the first linear guide device 23 via the first link mechanism 22. This allows the bed 4 to rotate about the roll axis r. Furthermore, when the bed 4 is rotated about the pitch axis p by the second drive unit 30, the first drive unit 20 can follow that movement by means of the first link mechanism 22.

[0082] In this embodiment, the first linear guide device 23 includes a track body 231 extending in the width direction (Y-axis direction), a moving body 232 that moves along the track body 231, and a plurality of balls 65 (rolling bodies) interposed between the track body 231 and the moving body 232. With this configuration, the moment load generated when the bed section 4 rotates can be distributed and borne by the plurality of balls 65. This allows the first drive device 20 to be made smaller.

[0083] In this embodiment, the first link mechanism 22 includes a first arm portion 220 extending in the width direction (Y-axis direction), a first coupling portion 221 that couples one end of the first arm portion 220 on the +Y side to the first connecting member 21 via a spherical bearing 224, and a second coupling portion 222 that couples the other end of the first arm portion 220 on the -Y side to the first linear guide device 23 via a spherical bearing 226. The first drive unit 20 includes an arm posture control device 25 that returns the first arm portion 220 to its original posture when the first arm portion 220 rotates around an axis O4 parallel to the pitch axis p. This configuration can prevent the first arm portion 220 from colliding with the movable block 233. Furthermore, the posture of the first arm portion 220 can be controlled so that the first arm portion 220, which has a high degree of freedom, reliably returns to its original posture.

[0084] Furthermore, in this embodiment, the second drive unit 30 includes a second link mechanism 32 that is coupled to the second connecting member 31 and follows at least the rotation of the bed 4 about the roll axis r, and a second linear guide device 33 that guides the second connecting member 31 in the height direction of the bed 4 via the second link mechanism 32. According to this configuration, the second connecting member 31 connected to the bed 4 is guided in the height direction (Z-axis direction) by the second linear guide device 33 via the second link mechanism 32. This allows the bed 4 to rotate about the pitch axis p. Furthermore, when the bed 4 is rotated about the roll axis r by the first drive unit 20, the second drive unit 30 can follow that movement by the second link mechanism 32.

[0085] In this embodiment, the second linear guide device 33 includes a track body 331 extending in the height direction (Z-axis direction), a moving body 332 that moves along the track body 331, and a plurality of balls 65 (rolling bodies) interposed between the track body 331 and the moving body 332. With this configuration, the moment load generated when the bed section 4 rotates can be distributed and borne by the plurality of balls 65. This allows the second drive device 30 to be made smaller.

[0086] In this embodiment, the second link mechanism 32 includes a second arm portion 320 extending in the height direction (Z-axis direction), a third coupling portion 321 that couples one end of the second arm portion 320 on the +Z side to the second connecting member 31 via a spherical bearing 324, and a fourth coupling portion 322 that couples the other end of the second arm portion 320 on the -Z side to the second linear guide device 33 so as to be rotatable about an axis O7 parallel to the pitch axis p. As shown in FIG. 7 , the spherical bearing 324 allows the second connecting member 31 to rotate about the axis O5. This allows the second connecting member 31 to follow the rotation of the table member 50 about the roll axis r. Meanwhile, the second drive unit 30 is disposed farther from the fulcrum portion 10 than the first drive unit 20. This means that there are cases where the second connecting member 31 cannot follow the rotation about the pitch axis p simply by rotating the spherical bearing 324 about the axis O6. Therefore, a thrust bushing 325 (see FIG. 12) is employed in the fourth linking portion 322 to allow the second connecting member 31 to rotate largely around the axis O7. This allows the second connecting member 31 to follow the rotation around the pitch axis p. In other words, the rotation angle around the pitch axis p can be increased.

[0087] As described above, according to the present embodiment, the bed section 4 can be rotated around the roll axis r and the pitch axis p with a compact device configuration.

[0088] While the preferred embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the above-described embodiments. The shapes and combinations of the components shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0089] According to the present invention, the bed section can be rotated around the roll axis and the pitch axis with a compact device configuration.

[0090] REFERENCE SIGNS LIST 1...bed device, 2...base portion, 3...tilting portion, 4...bed portion, 4a...one end, 4b...other end, 10...fulcrum portion, 11...through hole, 12...spherical bearing, 12a...outer ring, 12b...inner ring, 20...first driving device, 21...first connecting member, 22...first link mechanism, 23...first linear guide device, 24...worm gear unit, 25...arm attitude control device, 30...second driving device, 31...second connecting member, 32...second link mechanism, 33...second linear guide device, 34...worm gear unit, 40...base member, 50...table member, 51...first vertical portion, 52...second vertical portion, 53...shaft portion, 60... Linear guide, 61... raceway rail, 61a... upper surface, 61b... outer surface, 62... slider block, 63... rolling element rolling groove, 64... loaded rolling element rolling groove, 65... ball, 66... ​​fixing hole, 67... block main body, 67a... mounting surface, 68... cover body, 69... rail accommodating groove, 70... fixing hole, 71... rail accommodating groove, 200... first mounting plate, 210... connection portion main body, 211... first mounting hole, 212... second mounting hole, 213... shaft support portion, 214... shaft portion, 220... first arm portion, 221... first connecting portion, 222... second connecting portion, 223... through hole, 224... spherical bearing, 224a... outer ring, 224b... inner ring, 225...through hole, 226...spherical bearing, 226a...outer ring, 226b...inner ring, 231...raceway body, 232...moving body, 233...movable block, 233a...groove portion, 234...shaft portion, 235...nut, 241...ball screw shaft, 242...gear box, 243...motor connection portion, 250...plunger, 251...ball, 252...spring, 253...press screw, 300...second mounting plate, 301...rail support portion, 302...recess, 310...connection portion main body, 311...protrusion, 312...mounting hole, 313...shaft support portion, 314...shaft portion, 320...second arm portion, 321...third connecting portion, 322...fourth connecting portion , 323...through hole, 324...spherical bearing, 324a...outer ring, 324b...inner ring, 325...thrust bush, 331...raceway body, 332...moving body, 333...movable block, 333a...through hole, 334...nut, 335...fixed plate, 336...shaft, 341...ball screw shaft, 342...gear box, 343...motor connection part, C...infinite circulation path, C1...loaded rolling body rolling path, C2...unloaded rolling body rolling path, C3...rolling body direction change path, H...patient, O1...central axis, O2...axis, O3...axis, O4...axis, O5...axis, O6...axis, O7...axis, p...pitch axis, r...roll axis,y...yaw axis,

Claims

1. A bed device comprising: a bed section; and a tilting section that tilts the bed section, wherein the tilting section comprises: a fulcrum section that supports the bed section via a spherical bearing; a first drive unit that rotates the bed section around a roll axis centered on the fulcrum section; and a second drive unit that rotates the bed section around a pitch axis centered on the fulcrum section, wherein the fulcrum section, the first drive unit, and the second drive unit are arranged on a central axis that passes through the center of the width of the bed section.

2. The bed apparatus according to claim 1, wherein the tilting section supports one end of the bed section in a cantilever manner in the longitudinal direction.

3. A bed apparatus according to claim 2, wherein the fulcrum portion, the first drive device, and the second drive device are arranged in this order from the other end side of the bed portion in the longitudinal direction toward the one end side.

4. A bed apparatus as described in any one of claims 1 to 3, wherein the first drive device comprises a first connecting member connected to the bed section, the second drive device comprises a second connecting member connected to the bed section, and the fulcrum section, the first connecting member, and the second connecting member are arranged on the central axis of the bed section.

5. A bed apparatus as described in claim 4, wherein the first drive device comprises: a first link mechanism connected to the first connecting member and following at least the rotation of the bed section around the pitch axis; and a first linear guide device that guides the first connecting member in the width direction of the bed section via the first link mechanism.

6. A bed apparatus as described in claim 5, wherein the first linear guide device comprises a track body extending in the width direction, a moving body that moves along the track body, and a plurality of rolling bodies interposed between the track body and the moving body.

7. The bed apparatus according to claim 5, wherein the first link mechanism comprises: a first arm portion extending in the width direction; a first connecting portion connecting one end of the first arm portion in the width direction to the first connecting member via a spherical bearing; and a second connecting portion connecting the other end of the first arm portion in the width direction to the first linear guide device via a spherical bearing; and the first drive device comprises an arm attitude control device that returns the first arm portion to its original attitude when the first arm portion rotates around an axis parallel to the pitch axis.

8. A bed apparatus as described in claim 4, wherein the second drive device comprises: a second link mechanism connected to the second connecting member and following at least the rotation of the bed section around the roll axis; and a second linear guide device that guides the second connecting member in the height direction of the bed section via the second link mechanism.

9. A bed apparatus as described in claim 8, wherein the second linear guide device comprises a track body extending in the height direction, a moving body that moves along the track body, and a plurality of rolling bodies interposed between the track body and the moving body.

10. A bed device as described in claim 8, wherein the second link mechanism comprises: a second arm portion extending in the height direction; a third connecting portion connecting one end of the second arm portion in the height direction to the second connecting member via a spherical bearing; and a fourth connecting portion connecting the other end of the second arm portion in the height direction to the second linear guide device rotatably around an axis parallel to the pitch axis.

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