Drive mechanism for oral CBCT device and oral CBCT device having the same

Abstract

The present invention discloses a driving mechanism for an oral CBCT device and an oral CBCT device having the same. The guiding mechanism includes: a lead screw assembly, the lead screw assembly includes: a lead screw, the lead screw extends in the up and down direction, a rigid support member, the rigid support member is connected to the lower end of the lead screw for supporting the lower end of the lead screw, a flexible support member, the flexible support member is connected to the upper end of the lead screw for supporting the upper end of the lead screw; a nut assembly, the nut assembly includes: a nut bracket, a nut, the nut is swingably disposed on the nut bracket around an axis extending in the horizontal direction, and the nut is sleeved on the lead screw; a driving assembly, the driving assembly is connected to the lead screw, and the driving assembly is used to drive the lead screw to rotate to threadedly engage with the nut. According to the driving mechanism of the present invention, it can ensure that the lead screw and the nut always remain coaxial, so that the meshing area between the lead screw and the nut is the largest, the pressure is the smallest, the transmission efficiency is high, the accelerated wear of the nut is avoided, and the generation of noise and vibration abnormal sound is avoided.

Description

Technical Field

[0001] The present invention relates to a driving mechanism for an oral CBCT device and an oral CBCT device having the same. Background Art

[0002] In the related art, in a three-in-one oral CBCT (abbreviation of Cone beam CT, i.e., cone beam CT) (CT, panoramic, lateral), a sliding column drives a main rotating arm and a lateral arm to slide up and down to adjust the height to adapt to the heights of different patients being photographed. Since the cantilever lengths of the main rotating arm and the lateral arm are long and heavy, the sliding column is subjected to moments of forward tilt and lateral tilt in the corresponding directions.

[0003] Currently, the commonly used driving method is a combination of a motor and a lead screw. According to the different relatively stationary components, it is divided into two types. The motor and the lead screw are installed on the sliding column and move up and down together, and the nut is fixed on the column, and, the motor and the lead screw are installed on the column, and the nut is fixed on the sliding column and moves up and down together. However, the nut in the related art has a large wear and a low service life. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. For this reason, the present invention provides a driving mechanism for an oral CBCT device, in which the meshing area between the lead screw and the nut is large, the pressure is small, and the transmission efficiency is high.

[0005] The present invention also provides an oral CBCT device having the above driving mechanism.

[0006] The driving mechanism for an oral CBCT device according to the first aspect of the present invention includes: a lead screw assembly, the lead screw assembly includes: a lead screw, the lead screw extends in the up and down direction, a rigid support member, the rigid support member is connected to the lower end of the lead screw for supporting the lower end of the lead screw, a flexible support member, the flexible support member is connected to the upper end of the lead screw for supporting the upper end of the lead screw; a nut assembly, the nut assembly includes: a nut bracket, a nut, the nut is swingably disposed on the nut bracket around an axis extending in the horizontal direction, and the nut is sleeved on the lead screw; a driving assembly, the driving assembly is connected to the lead screw, and the driving assembly is used to drive the lead screw to rotate to be threadedly engaged with the nut.

[0007] According to the driving mechanism for an oral CBCT device of the present invention, it can ensure that the lead screw and the nut always remain coaxial, so that the meshing area between the lead screw and the nut is the largest, the pressure is the smallest, the transmission efficiency is high, and it can also avoid excessive local pressure at a certain part when the lead screw and the nut are meshed, resulting in accelerated wear of the nut, and avoid generating noise and vibration abnormal sounds.

[0008] In some embodiments, a first support portion is formed at the lower end of the lead screw, and the rigid support member is sleeved on the first support portion. The rigid support member includes: a rigid bearing seat, on which a bearing mounting hole is formed; a thrust bearing, which is disposed in the bearing mounting hole and sleeved on the first support portion.

[0009] In some embodiments, there are two thrust bearings, and the rigid support member further includes: a first bushing, which is sleeved on the first support portion and located between the two thrust bearings.

[0010] In some embodiments, the rigid support member further includes: a locknut, which is threadedly connected to the free end of the first support portion.

[0011] In some embodiments, the rigid support member further includes: an adjusting ring, which is sleeved on the first support portion and abuts against the upper surface of the thrust bearing.

[0012] In some embodiments, a second support portion is formed at the upper end of the lead screw, and the flexible support member is sleeved on the second support portion. The flexible support member includes: a flexible bearing seat, on which a bushing mounting hole is formed; a second bushing, which is disposed in the bushing mounting hole and sleeved on the second support portion.

[0013] In some embodiments, the drive assembly includes: a motor bracket; a drive motor, which is disposed on the motor bracket and has a drive shaft; a coupling, which is respectively in transmission connection with the drive shaft and the lead screw.

[0014] In some embodiments, a shaft hole penetrating the nut bracket in the left-right direction is formed on the nut bracket, and the nut assembly further includes: a rotating shaft, which is rotatably disposed in the shaft hole, and the nut is fixed on the rotating shaft.

[0015] In some embodiments, a nut connection hole extending perpendicular to the axis of the rotating shaft is formed on the rotating shaft, and at least part of the nut extends into the nut connection hole and is threadedly connected to the rotating shaft.

[0016] In some embodiments, a shaft shoulder is formed at one end of the rotating shaft along the axial direction, and the nut assembly further includes: a shaft end retaining plate, which is connected to the other end of the rotating shaft, and the shaft shoulder and the shaft end retaining plate respectively abut against the circumferences at both axial ends of the shaft hole.

[0017] The oral CBCT device according to the second aspect of the present invention includes: a base frame; a driving mechanism, which is the driving mechanism for the oral CBCT device according to the first aspect of the present invention; a sliding column, the sliding column is connected to one of the lead screw and the nut, and the other of the lead screw and the nut is fixed to the base frame, and the lead screw-nut driving mechanism is used to drive the sliding column to be movable relative to the base frame in the up-and-down direction; a guiding assembly, the guiding assembly is connected between the sliding column and the base frame for guiding the sliding column.

[0018] The oral CBCT device according to the present invention can ensure that the lead screw and the nut always remain coaxial, so that the meshing area between the lead screw and the nut is the largest, the pressure is the smallest, the transmission efficiency is high, and it can also avoid excessive local pressure at a certain part when the lead screw and the nut are meshing, resulting in accelerated wear of the nut, and avoid generating noise and abnormal vibration noise.

[0019] In some embodiments, the guiding assembly includes: a guide rod, the guide rod extends in the up-and-down direction and is fixed to the base frame; a first rolling member, the first rolling member is arranged on the guide rod, and the first rolling member includes: a first rolling element, the first rolling element is rotatable about a first axis extending in the left-and-right direction; a second rolling member, the second rolling member is arranged on the guide rod, and the second rolling member includes: a second rolling element, the second rolling element is rotatable about a second axis extending in the front-and-back direction; wherein, a chute extending in the up-and-down direction is formed on the sliding column, and the first rolling element and the second rolling element are rotatably arranged in the chute and abut against the inner wall of the chute.

[0020] In some embodiments, the first rolling member further includes: a first connecting shaft, the first rolling element is sleeved on the first connecting shaft, a connecting hole is provided on the guide rod, and the first connecting shaft is fixedly connected to the guide rod through the connecting hole.

[0021] In some embodiments, the free end of the first connecting shaft passes through the connecting hole, and the free end of the first connecting shaft is threadedly connected to the base frame.

[0022] In some embodiments, the second rolling member further includes: a support, the support is fixed to the guide rod, a receiving groove with an opening facing the bottom wall of the chute is formed on the support, the second rolling element is rotatably arranged in the receiving groove, and a part of the second rolling element extends out of the opening of the receiving groove.

[0023] In some embodiments, a through hole penetrating the receiving groove in the front-and-back direction is formed on the support, and the second rolling member further includes: a second connecting shaft, the second connecting shaft passes through the through hole and is fixed to the support, and the second rolling element is sleeved on the second connecting shaft.

[0024] In some embodiments, the second rolling member further includes an adjusting shim, and the adjusting shim is sleeved on the second connecting shaft and located between the second rolling member and the side wall of the receiving groove.

[0025] In some embodiments, the second rolling member further includes: a rubber cushion block, the rubber cushion block is fixed on the guide rod, and the support is connected to the rubber cushion block.

[0026] In some embodiments, a plurality of the first rolling members are included, and the plurality of first rolling members are arranged at intervals along the length direction of the guide rod; and / or a plurality of the second rolling members are included, and the plurality of second rolling members are arranged at intervals along the length direction of the guide rod.

[0027] In some embodiments, both the first rolling member and the second rolling member are rubber-coated bearings.

[0028] In some embodiments, side support plates extending in the up-and-down direction are provided on the base frame, the side support plates have a first plate portion and a second plate portion, both the first plate portion and the second plate portion extend in the front-and-back direction and are arranged at intervals and opposite to each other in the left-and-right direction, two guiding assemblies are included, the two guiding assemblies are respectively connected to the first plate portion and the second plate portion, the sliding column is arranged between the first plate portion and the second plate portion, and two sliding grooves corresponding to the two guiding assemblies one by one are formed on the sliding column.

[0029] In some embodiments, the side support plate further has a connecting plate portion, and the connecting plate portion extends in the left-and-right direction and is connected between the rear ends of the first plate portion and the second plate portion.

[0030] In some embodiments, the second rolling member is a rubber-coated member. When the sliding column is not assembled, the minimum distance in the horizontal direction between the second rolling member of the guiding assembly on the left side and the second rolling member of the guiding assembly on the right side is d1; the distance in the horizontal direction between the bottom wall of the sliding groove on the left side of the sliding column and the bottom wall of the sliding groove on the right side of the sliding column is d2; wherein, d1 and d2 satisfy: d1 is less than d2.

[0031] Additional aspects and advantages of the present invention will be given in part in the following description, will become apparent in part from the following description, or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is an exploded view of an oral CBCT device according to an embodiment of the present invention;

[0033] Figure 2Schematic diagram of an oral CBCT device according to an embodiment of the present invention;

[0034] Figure 3 is Figure 2 Schematic diagram of a top view of the oral CBCT device shown in;

[0035] Figure 4 is Figure 3 Enlarged view of area A circled in;

[0036] Figure 5 is Figure 2 Cross-sectional view of the oral CBCT device shown in;

[0037] Figure 6 is Figure 1 Schematic diagram of the guiding component shown in;

[0038] Figure 7 is Figure 6 Exploded view of the guiding component shown in;

[0039] Figure 8 is Figure 6 Schematic diagram of another angle of the guiding component shown in;

[0040] Figure 9 is Figure 8 Cross-sectional view of the guiding component shown in along line B-B;

[0041] Figure 10 is Figure 1 Schematic diagram of the driving mechanism shown in;

[0042] Figure 11 is Figure 10 Exploded view of the driving mechanism shown in;

[0043] Figure 12 is Figure 10 Schematic diagram of another angle of the driving mechanism shown in;

[0044] Figure 13 is Figure 12 Cross-sectional view of the driving mechanism shown in along line C-C;

[0045] Figure 14 is Figure 10 Schematic diagram of a three-dimensional view of the nut assembly shown in;

[0046] Figure 15 is Figure 14 Schematic diagram of a top view of the nut assembly shown in;

[0047] Figure 16 is along Figure 15 Cross-sectional view along line E-E in;

[0048] Figure 17 is a sectional view along Figure 15 the F-F line in

[0049] Reference numerals:

[0050] oral cavity CBCT device 100,

[0051] base frame 1, side support plate 11, first plate portion 111, second plate portion 112, connecting plate portion 113,

[0052] guide assembly 2,

[0053] guide rod 21, connecting hole 211,

[0054] first rolling member 22, first rolling element 221, first connecting shaft 222,

[0055] second rolling member 23, second rolling element 231, support 232, receiving groove 2321, through hole 2322, second connecting shaft 233, adjusting shim 234, rubber cushion block 235,

[0056] sliding column 3, sliding groove 31,

[0057] driving mechanism 4,

[0058] lead screw assembly 41,

[0059] lead screw 411, first support portion 4111, second support portion 4112,

[0060] rigid support member 412, rigid bearing seat 4121, bearing mounting hole 41211, thrust bearing 4122, first bushing 4123, locknut 4124, adjusting ring 4125,

[0061] flexible support member 413, flexible bearing seat 4131, bushing mounting hole 41311, second bushing 4132, driving assembly 42, motor bracket 421, driving motor 422, driving shaft 4221, coupling 423, nut assembly 43, nut bracket 431, shaft hole 4311, nut 432, rotating shaft 433, nut connection hole 4331, shaft shoulder 4332, shaft end retaining plate 434. Detailed implementation manners

[0062] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals indicate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0063] The drive mechanism 4 for the oral cavity CBCT device 100 according to the embodiment of the first aspect of the present invention will be described in detail below.

[0064] As Figure 1 , Figures 10 - 17 shown, the drive mechanism 4 for the oral cavity CBCT device 100 according to the embodiment of the present invention includes: a lead screw assembly 41, a drive assembly 42, and a nut assembly 43.

[0065] Specifically, as Figure 10 and Figure 11 shown, the lead screw assembly 41 may include: a lead screw 411, a rigid support member 412, and a flexible support member 413. Among them, the lead screw 411 extends in the up and down direction, the rigid support member 412 is connected to the lower end of the lead screw 411 for supporting the lower end of the lead screw 411, and the flexible support member 413 is connected to the upper end of the lead screw 411 for supporting the upper end of the lead screw 411.

[0066] As Figure 11 shown, the nut assembly 43 includes: a nut bracket 431 and a nut 432. The nut 432 is swingably disposed on the nut bracket 431 around an axis extending in the horizontal direction. The nut 432 is sleeved on the lead screw 411, and the nut 432 is in threaded engagement with the lead screw 411. The drive assembly 42 is connected to the lead screw 411, and the drive assembly 42 is used to drive the lead screw 411 to rotate to be in threaded engagement with the nut 432.

[0067] As Figure 1 shown, the sliding column 3 of the oral cavity CBCT device 100 is connected to one of the lead screw 411 and the nut 432, and the other of the lead screw 411 and the nut 432 is fixed to the base frame 1 of the oral cavity CBCT device 100. The drive mechanism 4 for the oral cavity CBCT device 100 in this embodiment is used for the lead screw 411 to engage with the nut 432 to realize the up and down movement of the sliding column 3 relative to the base frame 1. Among them, the cantilever and the lateral arm of the oral cavity CBCT device 100 are both disposed on the sliding column 3.

[0068] During the operation of the oral CBCT device 100, the cantilever and the lateral arm apply torques to the sliding column 3 in the front-rear direction and / or the left-right direction. These torques are transmitted to the lead screw 411 of the drive mechanism 4, causing the lead screw 411 to be subjected to a torque in the front-rear direction and / or a torque in the left-right direction. Since the upper end of the lead screw 411 is provided with a flexible support member 413 and the lower end is provided with a rigid support member 412, when the lead screw 411 is subjected to a torque in the front-rear direction or the left-right direction, due to the flexible support at the upper end, the lead screw 411 will produce a slight inclination or swing with the rigid support member 412 as the fulcrum or fixed point. At the same time, since the nut 432 in the nut assembly 43 can swing around an axis extending in the horizontal direction, when the lead screw 411 inclines or swings, the lead screw 411 can drive the nut 432 to incline or swing together, so that the lead screw 411 and the nut 432 always remain coaxial. In this way, the meshing area between the lead screw 411 and the nut 432 is the largest, the pressure is the smallest, the transmission efficiency is high, and it can also prevent excessive local pressure at a certain part during the meshing of the lead screw 411 and the nut 432 from causing accelerated wear of the nut 432, and avoid generating noise and abnormal vibration noise.

[0069] Therefore, the drive mechanism 4 for the oral CBCT device 100 according to the embodiments of the present invention can ensure that the lead screw 411 and the nut 432 always remain coaxial, so that the meshing area between the lead screw 411 and the nut 432 is the largest, the pressure is the smallest, the transmission efficiency is high, and it can also prevent excessive local pressure at a certain part during the meshing of the lead screw 411 and the nut 432 from causing accelerated wear of the nut 432, and avoid generating noise and abnormal vibration noise.

[0070] In some embodiments of the present invention, as Figure 11 shown, a first support portion 4111 is formed at the lower end of the lead screw 411, and the rigid support member 412 is sleeved on the first support portion 4111. The rigid support member 412 includes: a rigid bearing seat 4121 and a thrust bearing 4122. A bearing mounting hole 41211 is formed in the rigid bearing seat 4121; the thrust bearing 4122 is disposed in the bearing mounting hole 41211 and is sleeved on the first support portion 4111. Thus, rigid support for the lower end of the lead screw 411 can be achieved. Among them, the rigid bearing seat 4121 can be a metal bearing seat.

[0071] In some embodiments, as Figure 11 shown, there can be two thrust bearings 4122. The rigid support member 412 further includes: a first bushing 4123. The first bushing 4123 is sleeved on the first support portion 4111 and is located between the two thrust bearings 4122. Thus, the stability and reliability of the support of the rigid support member 412 for the lead screw 411 can be improved. Among them, optionally, the first bushing 4123 can be an oil-free bushing.

[0072] In some embodiments, as Figure 11 shown, the rigid support member 412 may further include: a locknut 4124, which is threadedly connected to the free end of the first support portion 4111. The locknut 4124 can lock and sleeve components such as a thrust bearing 4122 and a rigid bearing seat 4121 provided on the first support portion 4111 to prevent components (such as the thrust bearing 4122, the rigid bearing seat 4121, and the first bushing 4123) from slipping off.

[0073] In some embodiments, as Figure 11 shown, the rigid support member 412 may further include: an adjusting ring 4125, which is sleeved on the first support portion 4111 and abuts against the upper surface of the thrust bearing 4122. For example, the adjusting ring 4125 abuts between the end face of the fixed end of the first support portion 4111 and the upper surface of the upper thrust bearing 4122 among the two thrust bearings 4122. Thus, the support position of the thrust bearing 4122 can be adjusted by the adjusting ring 4125, and at the same time, the adjusting ring 4125 can also space the thrust bearing 4122 apart from the end face of the fixed end of the first support portion 4111 to prevent the end face of the fixed end from interfering with the thrust bearing 4122.

[0074] According to some embodiments of the present invention, as Figure 11 shown, a second support portion 4112 may be formed at the upper end of the lead screw 411, and the flexible support member 413 is sleeved on the second support portion 4112. The flexible support member 413 includes: a flexible bearing seat 4131 and a second bushing 4132. A bushing mounting hole 41311 is formed on the flexible bearing seat 4131; the second bushing 4132 is disposed in the bushing mounting hole 41311 and is sleeved on the second support portion 4112. Thus, flexible support at the upper end of the lead screw 411 can be achieved. Among them, the flexible bearing seat 4131 may be a rubber bearing seat, and the second bushing 4132 may be an oil-free bushing.

[0075] According to some embodiments of the present invention, as Figure 11 shown, the drive assembly 42 may include: a motor bracket 421, a drive motor 422, and a coupling 423. The drive motor 422 is disposed on the motor bracket 421, and the drive motor 422 has a drive shaft 4221; the coupling 423 is respectively in transmission connection with the drive shaft 4221 and the lead screw 411. During operation, the drive motor 422 drives the drive shaft 4221 to rotate, and the drive shaft 4221 drives the lead screw 411 to rotate through the coupling 423. Among them, optionally, the drive motor 422 may be a reduction motor.

[0076] According to some embodiments of the present invention, as Figure 11 , Figures 14 - 17As shown, a shaft hole 4311 penetrating the nut bracket 431 in the left-right direction is formed on the nut bracket 431. The nut assembly 43 may further include: a rotating shaft 433 rotatably disposed in the shaft hole 4311, and a nut 432 fixed to the rotating shaft 433. When the rotating shaft 433 rotates about an axis extending in the left-right direction, the rotating shaft 433 can drive the nut 432 to swing in the front-back direction. In other words, when the nut 432 is subjected to a moment in the front-back direction, the nut 432 can drive the rotating shaft 433 to swing in the front-back direction to ensure coaxiality with the lead screw 411.

[0077] Further, as Figure 11 shown, a nut connection hole 4331 extending perpendicular to the axis of the rotating shaft 433 may be formed on the rotating shaft 433, and at least a part of the nut 432 extends into the nut connection hole 4331 and is threadedly connected to the rotating shaft 433. For example, a nut connection hole 4331 extending in the up-down direction is formed on the rotating shaft 433. The nut connection hole 4331 may penetrate the rotating shaft 433 in the up-down direction, internal threads are formed in the nut connection hole 4331, and external threads are provided on the outer surface of the nut 432. The nut 432 is threadedly connected to the nut connection hole 4331. Thus, a fixed connection between the rotating shaft 433 and the nut 432 can be achieved, with reliable connection and convenient assembly.

[0078] In some examples, as Figure 11 shown, a shaft shoulder 4332 is formed at one end of the rotating shaft 433 along the axial direction (for example, the right end of the rotating shaft 433 shown in Figure 11 ). The nut assembly 43 may further include: a shaft end retaining plate 434 connected to the other end of the rotating shaft 433 (for example, the left end of the rotating shaft 433 shown in Figure 11 ). The shaft shoulder 4332 and the shaft end retaining plate 434 respectively abut against the circumferences at both axial ends of the shaft hole 4311. Thus, the shaft shoulder 4332 and the shaft end retaining plate 434 can play a role in limiting the rotating shaft 433 in the left-right direction.

[0079] According to an embodiment of the second aspect of the present invention, an oral CBCT device 100 includes: a base frame 1, a driving mechanism 4, a sliding column 3, and a guiding assembly 2. Among them, the driving mechanism 4 is the driving mechanism 4 for the oral CBCT device 100 according to the embodiment of the first aspect of the present invention. The sliding column 3 is connected to one of the lead screw 411 and the nut 432, and the other of the lead screw 411 and the nut 432 is fixed to the base frame 1. The driving mechanism 4 is used to drive the sliding column 3 to be movable relative to the base frame 1 in the up-down direction; the guiding assembly 2 is connected between the sliding column 3 and the base frame 1 for guiding the sliding column 3.

[0080] For the oral CBCT device 100 according to an embodiment of the present invention, since a flexible support member 413 is provided at the upper end of the lead screw 411 and a rigid support member 412 is provided at the lower end, when the lead screw 411 is subjected to a moment in the front-rear direction or a moment in the left-right direction, due to the flexible support at the upper end, the lead screw 411 will generate a slight inclination or swing with the rigid support member 412 as the fulcrum or fixed point relative to the rigid support member 412. At the same time, since the nut 432 in the nut assembly 43 can swing around an axis extending in the horizontal direction, when the lead screw 411 inclines or swings, the lead screw 411 can drive the nut 432 to incline or swing together, so that the lead screw 411 and the nut 432 always remain coaxial. In this way, the meshing area between the lead screw 411 and the nut 432 is the largest, the pressure is the smallest, the transmission efficiency is high, and it can also avoid excessive local pressure at a certain part when the lead screw 411 and the nut 432 are meshed, which causes accelerated wear of the nut 432 and avoids generating noise and vibration abnormal sounds.

[0081] The guiding mechanism for the oral CBCT device 100 according to the first aspect embodiment of the present invention will be described in detail below.

[0082] As Figure 1 and Figure 7 shown, the guiding mechanism for the oral CBCT device 100 according to an embodiment of the present invention includes: a base frame 1, a guiding assembly 2, and a sliding column 3.

[0083] Specifically, the guiding assembly 2 includes: a guide rod 21, a first rolling member 22, and a second rolling member 23. Among them, the guide rod 21 extends in the up-down direction (for example, the up-down direction shown in Figure 1 ), the guide rod 21 is fixed to the base frame 1, the first rolling member 22 is provided on the guide rod 21, and the first rolling member 22 includes: a first rolling element 221, and the first rolling element 221 is rotatable around a first axis extending in the left-right direction (for example, the left-right direction shown in Figure 1 ); the second rolling member 23 is provided on the guide rod 21, and the second rolling member 23 includes: a second rolling element 231, and the second rolling element 231 is rotatable around a second axis extending in the front-rear direction (for example, the front-rear direction shown in Figure 1 ).

[0084] The sliding column 3 is provided on the guiding assembly 2, and the sliding column 3 is slidable relative to the guiding assembly 2 in the up-down direction. A sliding groove 31 is formed on the sliding column 3, and the sliding groove 31 extends in the up-down direction. The first rolling element 221 and the second rolling element 231 are rotatably provided in the sliding groove 31 and abut against the inner wall of the sliding groove 31. For example, the first rolling element 221 can abut against the front side wall and / or the rear side wall of the sliding groove 31, and the second rolling element 231 can abut against the bottom wall of the sliding groove 31.

[0085] Optionally, the first rolling member 221 may be a bearing, and the second rolling member 231 may also be a bearing. Of course, the present invention is not limited thereto. The first rolling member 221 and the second rolling member 231 may also be other rollable members such as rollers, as long as they can achieve rolling cooperation with the inner wall of the sliding groove 31.

[0086] Here, it should be noted that the guiding mechanism of the oral CBCT device 100 in the related art usually adopts a linear guide rail or a slider. Although the linear guide rail is a commonly used guiding mechanism in industry, it is relatively expensive and requires high installation accuracy; while the slider solution has a lower cost, but the assembly requires adjustment, and the sliding friction is large. The slider wears greatly after long-term use and has a low service life.

[0087] Therefore, the guiding mechanism for the oral CBCT device 100 in this embodiment is provided with a first rolling member 221 and a second rolling member 231 on the guiding assembly 2 whose rotation axes are perpendicular to each other to guide the sliding column 3. During the up and down sliding of the sliding column 3, the first rolling member 221 can limit the sliding column 3 in the front and back directions, and the second rolling member 231 can limit the rolling column in the left and right directions, so as to realize the guiding of the rolling member during the up and down sliding. Therefore, compared with the slider solution in the related art, in the guiding mechanism of this embodiment, the first rolling member 221 and the second rolling member 231 and the inner wall of the sliding groove 31 on the sliding column 3 are in rolling friction, with small friction and small wear. At the same time, compared with the linear guide rail in the related art, the guiding mechanism of this embodiment has lower installation accuracy requirements, larger allowable errors, stronger flexibility, higher assembly efficiency, and lower cost.

[0088] In an embodiment of the present invention, as Figure 7 shown, to facilitate the rotatable connection between the first rolling member 221 and the guide rod 21 so that the first rolling member 221 can rotate around the first axis extending left and right, the first rolling member 22 may further include: a first connecting shaft 222, the first rolling member 221 is sleeved on the first connecting shaft 222, a connecting hole 211 is provided on the guide rod 21, and the first connecting shaft 222 is fixedly connected to the guide rod 21 through the connecting hole 211.

[0089] Further, referring to Figure 1 and Figure 7 , one end of the first connecting shaft 222 passes through the connecting hole 211 and is threadedly connected to the base frame 1. In this way, the first connecting shaft 222 can not only fix the first rolling member 221 on the guide rod 21, but also fix the guide rod 21 on the base frame 1. Therefore, the number of components can be reduced and the assembly efficiency can be improved.

[0090] In some embodiments of the present invention, as Figure 7As shown in the figure, for the convenience of rotatably connecting the second rolling member 231 to the guide rod 21 so that the second rolling member 231 can rotate around the second axis extending in the front-rear direction, the second rolling member 23 may further include: a support 232, the support 232 is fixed on the guide rod 21, a receiving groove 2321 is formed on the support 232, the opening of the receiving groove 2321 faces the bottom wall of the sliding groove 31, the second rolling member 231 is rotatably arranged in the receiving groove 2321, and a part of the second rolling member 231 extends out of the opening of the receiving groove 2321 to abut against the bottom wall of the sliding groove 31. When the sliding column 3 moves up and down, the second rolling member 231 can roll-friction with the bottom wall of the sliding groove 31 to achieve the guiding effect on the sliding column 3.

[0091] Further, as Figure 7 and with reference to Figure 1 shown in the figure, a through hole 2322 penetrating the support 232 in the front-rear direction may be formed on the support 232, the through hole 2322 is communicated with the receiving groove 2321, the second rolling member 23 may further include: a second connecting shaft 233, the second connecting shaft 233 passes through the through hole 2322 and is fixed on the support 232, and the second rolling member 231 is sleeved on the second connecting shaft 233. Thus, the second connecting shaft 233 can conveniently rotatably connect the second rolling member 231 to the support 232.

[0092] In some embodiments, as Figure 7 shown in the figure, the second rolling member 23 may further include an adjusting shim 234, the adjusting shim 234 is sleeved on the second connecting shaft 233, and the adjusting shim 234 is located between the second rolling member 231 and the side wall of the receiving groove 2321. Thus, the adjusting shim 234 can adjust the interval between the second rolling member 231 and the side wall of the receiving groove 2321 to avoid interference between the second rolling member 231 and the side wall of the receiving groove 2321.

[0093] In some embodiments, as Figure 7 shown in the figure, the second rolling member 23 may further include: a rubber cushion block 235, the rubber cushion block 235 is fixed on the guide rod 21, and the support 232 is connected to the rubber cushion block 235. In this embodiment, the support 232 is fixed on the guide rod 21 by using the rubber cushion block 235. On the one hand, the rubber cushion block 235 can buffer the vibration transmission between the support 232 and the guide rod 21. At the same time, because the rubber cushion block 235 has elasticity, during the assembly process, the requirement for the assembly accuracy of the second rolling member 231 can be reduced, the assembly efficiency can be improved, and the cost can be reduced. Specifically, by using the elastic deformation of the rubber cushion block 235, the assembled second rolling member 231 can generate pressure on the inner wall of the sliding groove 31. In this way, not only the stability of the sliding column 3 can be ensured, but also the tolerance requirement for the assembly distance between the sliding column 3 and the guiding component 2 in the left-right direction can be reduced.

[0094] Among them, the support 232 and the rubber cushion block 235 can be fixed to the guide rod 21 through connecting pieces such as screws.

[0095] In some embodiments, as Figure 7 shown, there can be multiple first rolling members 22, and multiple first rolling elements 221 are arranged at intervals along the length direction of the guide rod 21 (for example, Figure 7 the up-and-down direction shown in the figure); thereby, the guiding accuracy of the sliding column 3 can be improved, the skewing of the sliding column 3 under the action of the front-back moment and the left-right moment can be avoided, and the stability of the movement of the sliding column 3 can be improved.

[0096] In some embodiments, as Figure 7 shown, there can be multiple second rolling members 23, and multiple second rolling elements 231 are arranged at intervals along the length direction of the guide rod 21 (for example, Figure 7 the up-and-down direction shown in the figure). Thereby, the guiding accuracy of the sliding column 3 can be improved, the skewing of the sliding column 3 under the action of the front-back moment and the left-right moment can be avoided, and the stability of the movement of the sliding column 3 can be ensured.

[0097] As Figure 7 shown, the guiding assembly 2 can include a guide rod 21, two first rolling members 22, and two second rolling members 23. The guide rod 21 extends in the up-and-down direction, the guide rod 21 is in the shape of a plate strip extending in the up-and-down direction, the two first rolling members 22 are respectively arranged at both ends of the guide rod 21 in the length direction, the two second rolling members 23 are respectively arranged at both ends of the guide rod 21 in the length direction, and the first rolling member 22 at the upper end of the guide rod 21 is located above the second rolling member 23, and the first rolling member 22 at the lower end of the guide rod 21 is located below the second rolling member 23. In other words, the two second rolling members 23 are located between the two first rolling members 22.

[0098] In some embodiments, referring to Figure 7 shown, the first rolling element 221 can be a rubber-coated bearing, and the second rolling element 231 can be a rubber-coated bearing. Among them, the outer surface material of the rubber-coated bearing can be POM (polyformaldehyde, Chinese name: polyoxymethylene, a thermoplastic crystalline polymer) or wear-resistant rubber such as nylon. In this embodiment, by setting the first rolling element 221 and the second rolling element 231 as rubber-coated bearings, the direct hard contact between the first rolling element 221 and the second rolling element 231 and the sliding column 3 can be avoided, the hard friction can be reduced, and the service life can be improved.

[0099] According to some embodiments of the present invention, as Figure 1As shown, the base frame 1 may be provided with side support plates 11 extending in the vertical direction. The side support plates 11 have a first plate portion 111 and a second plate portion 112. Both the first plate portion 111 and the second plate portion 112 extend in the front-rear direction, and the first plate portion 111 and the second plate portion 112 are spaced apart and oppositely arranged in the left-right direction. The guiding assemblies 2 may include two, and the two guiding assemblies 2 are respectively connected to the first plate portion 111 and the second plate portion 112. The sliding column 3 is disposed between the first plate portion 111 and the second plate portion 112, and two sliding grooves 31 corresponding to the two guiding assemblies 2 one by one are formed on the sliding column 3. For example, the guiding assembly 2 on the left side of the sliding column 3 among the two guiding assemblies 2 is connected to the first plate portion 111, and a sliding groove 31 is formed on the left side of the sliding column 3. This sliding groove 31 is opposite to and connected to the guiding assembly 2 on the left side of the sliding column 3; the guiding assembly 2 on the right side of the sliding column 3 among the two guiding assemblies 2 is connected to the second plate portion 112, and a sliding groove 31 is also formed on the right side of the sliding column 3. This sliding groove 31 is opposite to and connected to the guiding assembly 2 on the right side of the sliding column 3.

[0100] Further, as Figure 1 shown, the side support plate 11 may further have a connecting plate portion 113. The connecting plate portion 113 extends in the left-right direction and is connected between the rear ends of the first plate portion 111 and the second plate portion 112. Thus, an installation space may be defined among the connecting plate portion 113, the first plate portion 111, and the second plate portion 112. The sliding column 3, the guiding assemblies 2, and the driving assembly 42 may all be disposed in this installation space. At the same time, the connecting plate portion 113 may also enhance the integrity between the first plate portion 111 and the second plate portion 112, improve the strength of the side support plate 11, and improve the stability of the side support plate 11 in supporting the sliding column 3.

[0101] In some embodiments, as Figure 1 shown, the side support plate 11 may include an inner plate, an outer plate, and connecting ribs connecting between the inner plate and the outer plate. Among them, the cross-section of the inner plate in the horizontal plane is U-shaped, and the cross-section of the outer plate in the horizontal plane is also U-shaped. The inner plate is disposed inside the outer plate, and the two U-shaped free ends of the inner plate are respectively connected to the two U-shaped free ends of the outer plate. The connecting ribs are located between the inner plate and the outer plate and connect between the inner plate and the outer plate. Thus, the strength of the side support plate 11 can be enhanced, the material consumption can be reduced, and the cost can be lowered.

[0102] In some embodiments of the present invention, referring to Figure 3 and Figure 4, the second rolling member 231 can be a rubber-coated member. When the sliding column 3 is not assembled, the minimum distance in the horizontal direction between the second rolling members 231 of the guiding assembly 2 on the left side and the second rolling members 231 of the guiding assembly 2 on the right side is d1, and the distance in the horizontal direction between the bottom walls of the sliding grooves 31 on the left side of the sliding column 3 and the bottom walls of the sliding grooves 31 on the right side of the sliding column 3 is d2; wherein, d1 and d2 satisfy: d1 is less than d2. That is to say, before assembly, the minimum distance between the second rolling members 231 on the left and right sides of the sliding column 3 is less than the distance between the bottom walls of the two sliding grooves 31 on the left and right sides of the sliding column 3. In this way, the elastic deformation of the rubber cushion block 235 can be utilized to make the second rolling member 231 generate pressure on the inner wall of the sliding groove 31 after assembly. Thus, not only the stability of the sliding column 3 can be ensured, but also the tolerance requirements for the assembly distance between the sliding column 3 and the guiding assembly 2 in the left and right directions can be reduced.

[0103] Next, refer to Figure 1 to describe the oral CBCT device 100 according to a specific embodiment of the present invention.

[0104] Refer to Figure 1 , the oral CBCT device 100 according to the embodiment of the present invention includes: a driving mechanism 4 and a guiding mechanism.

[0105] Specifically, as Figure 1 shown, the guiding mechanism is composed of a base frame 1, a guiding assembly 2, and a sliding column 3. The base frame 1 is composed of columns, side support plates 11, a bottom plate, and floor feet, providing fixed support. The guiding assemblies 2 are respectively installed on the left and right sides of the side support plates 11 to provide front-back, left-right guiding. The lead screw assembly 41 of the driving mechanism 4 is connected to the sliding column 3, and the nut 432 is connected to the side support plate 11. Therefore, the driving mechanism 4 and the sliding column 3 move up and down together.

[0106] The assembly relationship of the oral CBCT device 100 is shown in Figures 2 - 5 , a cantilever and a lateral arm (not shown in the figure) are connected to the top of the sliding column 3 to realize the up and down movement of the imaging function module. The guiding assembly 2 is composed of a guide rod 21, a first rubber-coated bearing (first rolling member 221), a first connecting shaft 222, a second rubber-coated bearing (second rolling member 231), a second connecting shaft 233, an adjusting gasket 234, and a support 232. The first rubber-coated bearing and the first connecting shaft 222 are cooperatively installed at the upper and lower ends of the guide rod 21 respectively. There is a threaded hole at the end of the first connecting shaft 222, which is installed on the two inner sides of the side support plate 11. The second rubber-coated bearing and the second connecting shaft 233 are cooperatively installed on the support 232, and the interval is adjusted by the adjusting gasket 234. The support 232 is installed on the guide rod 21 through the rubber cushion block 235. The assembly relationship is shown in Figure 6 and Figure 9 .

[0107] Refer to Figure 3 and Figure 4, the sliding column 3 bears moments in both the front-rear and left-right directions. The two first rubber-coated bearings above and below contact the front-rear rolling surfaces (the front side wall and the rear side wall of the chute 31) of the sliding column 3 to achieve its front-rear guidance. The two second rubber-coated bearings contact the side rolling surface (the bottom wall of the chute 31) to achieve lateral guidance. The outer surface materials of the first rubber-coated bearings and the second rubber-coated bearings are wear-resistant plastics such as POM or nylon.

[0108] Before assembly, the minimum distance between the two second rubber-coated bearings on the left and right sides of the side support plate 11 is less than the distance between the left and right rolling surfaces (the bottom wall of the chute 31) of the sliding column 3. By using the elastic deformation of the rubber cushion block 235, the second rubber-coated bearing generates a pre-pressure on the side rolling surface after assembly. This can maintain the stability of the sliding column 3, and at the same time, the deformation caused by the side torque can be offset by adjusting the up-down interference amount of the second rubber-coated bearing. Meanwhile, the tolerance requirement for the lateral distance of the sliding column 3 is reduced.

[0109] The guiding mechanism of the embodiment of the present invention can simultaneously perform front-rear and left-right limit guiding of the sliding column 3. Meanwhile, its structural characteristics result in low installation accuracy requirements, large allowable errors, strong flexibility, rolling friction in all directions of front, rear, left, and right, small friction coefficients, and lower costs.

[0110] According to the driving mechanism 4 for the oral cavity CBCT device 100 of the embodiment of the present invention, as Figure 1 , Figure 10 and Figure 11 shown, the driving component 42 is installed on the sliding column 3, and the nut component 43 is installed on the column.

[0111] The driving motor 422 with a reducer drives the lead screw 411 to rotate through the coupling 423. The lead screw assembly 41 includes a lead screw 411, a flexible support member 413, and a rigid support member 412. Among them, the flexible bearing seat 4131 of the flexible support member 413 is made of rubber, and the second bushing 4132 is an oil-free bushing and is installed in the flexible bearing seat 4131 to support the upper shaft of the lead screw 411. The rigid bearing seat 4121 of the rigid support member 412 is made of metal. The lead screw 411 passes through the adjusting ring 4125, the thrust bearing 4122, the first bushing 4123, the thrust bearing 4122 respectively and is locked with a locknut 432, as Figure 10 and Figure 11 . At this time, the rigid bearing seat 4121 plays the role of axial load-bearing support. Since there is a slight gap between the lower end shaft of the lead screw 411 and the first bushing 4123, and the upper bearing seat connected to the upper end is made of rubber material with a certain flexibility. Therefore, the lead screw 411 can swing slightly instead of being completely rigidly connected.

[0112] As Figure 11As shown in the figure, the nut assembly 43 includes: a nut bracket 431, a nut 432, a rotating shaft 433, and a shaft end retaining plate 434. Among them, the nut bracket 431 is installed on the side support plate 11. The nut bracket 431 is provided with a shaft hole 4311. The rotating shaft 433 with a shaft shoulder 4332 passes through the shaft hole 4311 and is axially limited by a shaft end retaining ring. A nut connection hole 4331 is formed in the middle of the rotating shaft 433, and the copper nut 432 passes through the nut connection hole 4331 and is threadedly fixed. Therefore, the copper nut 432 can rotate within the shaft hole 4311 of the nut bracket 431 along with the rotating shaft 433.

[0113] During actual operation, the sliding column 3 is guided in the front-back, left-right directions by the guiding assembly 2. However, there are errors in the dimensions and assembly of the first rubber-coated bearing (the first rolling element 221) and the second rubber-coated bearing (the second rolling element 231) of the guiding assembly 2 and the mating rolling surfaces (the front side wall, the rear side wall, and the bottom wall of the sliding groove 31), and there are also errors in the dimensions and assembly of the screw rod 411 and the sliding column 3. Therefore, it is impossible to ensure that the guiding axis is parallel to the axis of the screw rod 411, and even the axis included angle will change at different lifting heights. And during long-term use, the rubber-coated bearings (the first rolling element 221 and the second rolling element 231) will wear, resulting in a change in the included angle between the guiding axis and the axis of the screw rod 411. Therefore, in the oral CBCT device 100 of this embodiment, the copper nut 432 can adapt to the swing of the axis of the screw rod 411 and maintain coaxiality. In this way, the meshing area between the screw rod 411 and the copper nut 432 is the largest, the pressure is the smallest, the transmission efficiency is the highest, and there will be no vibration or abnormal noise.

[0114] In the oral CBCT device 100 according to the embodiment of the present invention, the motor and the screw rod 411 of the driving mechanism 4 are installed on the sliding column 3 and move up and down together with the sliding column 3. The nut 432 connected to the side support plate 11 has a swinging degree of freedom, and at the same time, the screw rod 411 also has a certain front-back degree of freedom. Thus, it can be ensured that the nut 432 and the screw rod 411 are coaxial along the guiding direction, avoiding excessive local pressure between the screw rod 411 and the nut 432, and avoiding accelerated wear of the nut 432 and the resulting vibration and abnormal noise.

[0115] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0116] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0117] In the present invention, unless otherwise clearly specified and defined, terms such as "installed", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or a communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0118] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0119] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A driving mechanism for an oral CBCT device, characterized in that, it includes: A lead screw assembly, the lead screw assembly includes: A lead screw, the lead screw extends in the up and down direction, A rigid support member, the rigid support member is connected to the lower end of the lead screw for supporting the lower end of the lead screw, A flexible support member, the flexible support member is connected to the upper end of the lead screw for supporting the upper end of the lead screw; A nut assembly, the nut assembly includes: A nut bracket, A nut, the nut is swingably arranged on the nut bracket around an axis extending in the horizontal direction, and the nut is sleeved on the lead screw; A driving component, the driving component is connected to the lead screw, and the driving component is used to drive the lead screw to rotate to be threadedly engaged with the nut; A first support portion is formed at the lower end of the lead screw, the rigid support member is sleeved on the first support portion, and the rigid support member includes: A rigid bearing seat, the rigid bearing seat is a metal bearing seat, and a bearing mounting hole is formed on the rigid bearing seat; A thrust bearing, the thrust bearing is arranged in the bearing mounting hole, and the thrust bearing is sleeved on the first support portion; A second support portion is formed at the upper end of the lead screw, the flexible support member is sleeved on the second support portion, and the flexible support member includes: A flexible bearing seat, the flexible bearing seat is a rubber bearing seat, and a bushing mounting hole is formed on the flexible bearing seat; A second bushing, the second bushing is arranged in the bushing mounting hole, and the second bushing is sleeved on the second support portion; An axial hole penetrating the nut bracket in the left and right directions is formed on the nut bracket, and the nut assembly further includes: a rotating shaft, the rotating shaft is rotatably arranged in the axial hole, and the nut is fixed on the rotating shaft, A nut connection hole extending perpendicular to the axis of the rotating shaft is formed on the rotating shaft, and at least a part of the nut extends into the nut connection hole and is threadedly connected to the rotating shaft.

2. The driving mechanism for an oral CBCT device according to claim 1, characterized in that, There are two thrust bearings, and the rigid support member further includes: a first bushing, the first bushing is sleeved on the first support portion and is located between the two thrust bearings.

3. The driving mechanism for an oral CBCT device according to claim 1, characterized in that, The rigid support member further includes: a locknut, the locknut is threadedly connected to the free end of the first support portion.

4. The driving mechanism for an oral CBCT device according to claim 1, characterized in that, The rigid support member further includes: an adjusting ring, the adjusting ring is sleeved on the first support portion and abuts against the upper surface of the thrust bearing.

5. The driving mechanism for an oral CBCT device according to claim 1, characterized in that, The driving component includes: A motor bracket; A driving motor, the driving motor is arranged on the motor bracket, and the driving motor has a driving shaft; A coupling, the coupling is respectively in transmission connection with the driving shaft and the lead screw.

6. The driving mechanism for an oral CBCT device according to claim 1, characterized in that, one end of the rotating shaft along the axial direction forms a shaft shoulder, and the nut assembly further includes: a shaft end retaining plate, the shaft end retaining plate is connected to the other end of the rotating shaft, and the shaft shoulder and the shaft end retaining plate respectively abut against the circumferences at both axial ends of the shaft hole.

7. An oral CBCT device, characterized in that, comprising: a base frame; a driving mechanism, the driving mechanism is the driving mechanism for an oral CBCT device according to any one of claims 1-6; a sliding column, the sliding column is connected to one of the lead screw and the nut, and the other of the lead screw and the nut is fixed to the base frame, and the lead screw-nut driving mechanism is used to drive the sliding column to be movable relative to the base frame in the up and down direction; a guiding assembly, the guiding assembly is connected between the sliding column and the base frame for guiding the sliding column.

8. The oral CBCT device according to claim 7, characterized in that, the guiding assembly includes: a guide rod, the guide rod extends in the up and down direction and is fixed to the base frame; a first rolling member, the first rolling member is arranged on the guide rod, and the first rolling member includes: a first rolling element, the first rolling element is rotatable around a first axis extending in the left and right direction; a second rolling member, the second rolling member is arranged on the guide rod, and the second rolling member includes: a second rolling element, the second rolling element is rotatable around a second axis extending in the front and back direction; wherein, a chute extending in the up and down direction is formed on the sliding column, and the first rolling element and the second rolling element are both rotatably arranged in the chute and abut against the inner wall of the chute.

9. The oral CBCT device according to claim 8, characterized in that, the first rolling member further includes: a first connecting shaft, the first rolling element is sleeved on the first connecting shaft, a connecting hole is arranged on the guide rod, and the first connecting shaft is fixedly connected to the guide rod through the connecting hole.

10. The oral CBCT device according to claim 9, characterized in that, the free end of the first connecting shaft passes through the connecting hole, and the free end of the first connecting shaft is threadedly connected to the base frame.

11. The oral CBCT device according to claim 8, characterized in that, the second rolling member further includes: a support, the support is fixed to the guide rod, a receiving groove with an opening facing the bottom wall of the chute is formed on the support, the second rolling element is rotatably arranged in the receiving groove, and a part of the second rolling element extends out of the opening of the receiving groove.

12. The oral CBCT device according to claim 11, characterized in that, a through hole extending in the front and back direction and penetrating the receiving groove is formed on the support, and the second rolling member further includes: a second connecting shaft, the second connecting shaft passes through the through hole and is fixed to the support, and the second rolling element is sleeved on the second connecting shaft.

13. The oral CBCT device according to claim 12, characterized in that, The second rolling member further includes an adjusting shim, and the adjusting shim is sleeved on the second connecting shaft and located between the second rolling member and the side wall of the accommodating groove.

14. The oral CBCT device according to claim 11, wherein, the second rolling member further includes: a rubber cushion block, the rubber cushion block is fixed on the guide rod, and the support is connected to the rubber cushion block.

15. The oral CBCT device according to any one of claims 8-14, wherein, a plurality of the first rolling members are included, and the plurality of first rolling members are arranged at intervals along the length direction of the guide rod; and / or a plurality of the second rolling members are included, and the plurality of second rolling members are arranged at intervals along the length direction of the guide rod.

16. The oral CBCT device according to any one of claims 8-14, wherein, both the first rolling member and the second rolling member are rubber-coated bearings.

17. The oral CBCT device according to claim 8, wherein, a side support plate extending in the up-down direction is provided on the base frame, the side support plate has a first plate portion and a second plate portion, both the first plate portion and the second plate portion extend in the front-back direction and are arranged at intervals and oppositely in the left-right direction, two guiding assemblies are included, the two guiding assemblies are respectively connected to the first plate portion and the second plate portion, the sliding column is arranged between the first plate portion and the second plate portion, and two sliding grooves corresponding to the two guiding assemblies one by one are formed on the sliding column.

18. The oral CBCT device according to claim 17, wherein, the side support plate further has a connecting plate portion, and the connecting plate portion extends in the left-right direction and is connected between the rear ends of the first plate portion and the second plate portion.

19. The oral CBCT device according to claim 8, wherein, the second rolling member is a rubber-coated member, when the sliding column is not assembled, the minimum distance in the horizontal direction between the second rolling member of the guiding assembly on the left side and the second rolling member of the guiding assembly on the right side is d1; the distance in the horizontal direction between the bottom wall of the sliding groove on the left side of the sliding column and the bottom wall of the sliding groove on the right side of the sliding column is d2; wherein, d1 and d2 satisfy: d1 is less than d2.

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