Motorized c-arm system

Abstract

The invention relates to an X-ray system comprising a C-shaped arc stand (102) provided with an X-ray source and an X-ray detector, and a carriage (101) of the C-shaped arc stand (102), which is adapted to fixedly hold the C-shaped arc stand (102) on the carriage (101). Furthermore, a drive device for driving the C-shaped arc stand (102) in rotation about a main axis (1000) comprises an electric motor (10, 110) (with a rotor and a stator) and a transmission mechanism (20, 120), which is arranged to transmit a movement generated by the electric motor (10, 110) to the C-shaped arc stand (102) in rotation about the main axis (1000). The transmission mechanism (20, 120) has a predetermined transmission ratio and comprises an input end, to which the rotor is mounted, and an output end, to which the stator and the C-shaped arc stand (102) are mounted.

Description

Technical Field

[0001] This disclosure generally relates to medical imaging systems, and more specifically, to a motor assembly of a C-arm system. Background Technology

[0002] A C-arm is a medical imaging system commonly used in hospitals, medical centers, and other healthcare facilities. It's an X-ray machine with a C-shaped frame ("C-arch") that allows the radiation source and detector to rotate and align axially for various examinations and surgeries. The C-arm is designed to provide high-quality images of bones, joints, and internal organs, and is particularly useful in surgery. It allows surgeons to visualize the surgical field during procedures and acquire real-time images to guide surgical actions.

[0003] The C-arm is designed to move in multiple directions, such as translating horizontally or vertically, or rotating about different axes. Furthermore, the C-arm can be equipped with various electric components to (semi-)automatically achieve these movements. These components should be compact to minimize the footprint of the C-arm. In particular, the drive systems for the rotational movements of the C-frame should be as small as possible, especially since they are typically located closer to the core of the C-arm system (i.e., the C-frame) than the drive systems for translational movements. These rotational movements can include propulsive movements (rotation about a main horizontal axis that substantially "divides" the "C" or C-frame into two symmetrical parts) and / or angular movements (rotation about a transverse horizontal axis orthogonal to the main horizontal axis).

[0004] Compared to fixed X-ray systems, compact design is particularly important for mobile X-ray systems. Mobile systems are more prone to collisions, and the environments used for different types of surgery vary in size and layout. In addition to electric operation, there are also some manual operations involving the C-arm. Summary of the Invention

[0005] Exemplary embodiments of this disclosure provide a solution to at least address the aforementioned problems existing in the prior art.

[0006] In one embodiment, this disclosure relates to an X-ray system comprising: a C-shaped arc frame equipped with an X-ray source and an X-ray detector (or to be equipped with an X-ray source and an X-ray detector); and a bracket (also referred to as a frame) for the C-shaped arc frame, adapted to securely hold the C-shaped arc frame on the bracket. Furthermore, a drive mechanism preferably arranged with or on the bracket, or functionally arranged between the C-shaped arc frame and the bracket, for driving the C-shaped arc frame to rotate about a main shaft includes a motor (having a rotor and a stator) and a transmission mechanism arranged to transmit the motion generated by the motor to the C-shaped arc frame rotating about the main shaft. The transmission mechanism, having a predetermined transmission ratio, includes an input end and an output end, with the rotor mounted to the input end and the stator and the C-shaped arc frame mounted to the output end.

[0007] Mounting the stator (and the motor housing, which is indirectly and often integral with or mounted on the stator) to the drive mechanism avoids mounting the stator to a bracket (or support), where mounting the motor to a bracket typically involves cumbersome fasteners (such as screws) and damping elements. Therefore, the arrangement according to this embodiment is more compact. Another result of mounting the stator to the output end of the drive mechanism is that the stator rotates with the C-arm – which necessitates corresponding adjustments to the motor control. In other words, contrary to most conventional choices in mechanical design within the field of this invention, the inventors have recognized that arranging the stator in this unconventional manner (where the stator is typically fixed to a fixed ground reference, as is the practice specified by motor manufacturers) helps to obtain some of the advantages of the invention presented herein. Another advantage is that the C-arm system is easier to maintain: for example, as described in more detail in this disclosure, the motor can be replaced without disassembling all core components of the propulsion device.

[0008] In one particular embodiment, the transmission mechanism includes a rotatable shaft mounted on the C-shaped arc frame and the output end and rotatable about the main axis, and a fixed shaft mounted on the bracket to securely hold the transmission mechanism, thereby facilitating the advancing movement of the C-shaped arc frame. Preferably, the rotatable shaft and the fixed shaft are coaxially arranged about the main axis, which further improves the compactness of the drive device. In one particular case, the rotatable shaft has an inner cavity extending along the main axis, and at least a portion of the fixed shaft is disposed within this inner cavity. In this way, the C-shaped arc frame can be fixed to the free end portion of the hollow shaft on a wider surface (because the hollow shaft, as an external shaft element, has significant surrounding free space that can extend away from the main axis) and at a position away from the main axis. Optionally, the fixed shaft is fixed to the bracket by a keyless bushing to allow the torque applied to the fixed shaft (especially in manual mode) to slip. Optionally, the fixed shaft is held by an intermediate support on which a potentiometer is disposed, which engages with the hollow shaft to measure angular position. In one particular embodiment, a (spiral) cable (e.g., for powering and receiving power or data from a motor and / or an electromagnetic lock and / or some sensing elements such as potentiometers and encoders) is provided in the gap between the rotatable shaft and the fixed shaft, further improving the compactness of the drive device.

[0009] In one particular embodiment, the transmission ratio (output / input) of the transmission mechanism is preferably equal to or less than 1 / 50, more specifically equal to or less than 1 / 100, more specifically equal to or less than 1 / 150, and even more preferably about 1 / 160.

[0010] In one particular embodiment, the transmission mechanism includes a harmonic driver, the harmonic driver The wave generator at the input terminal; The output end is a circular rigid wheel; The flexible wheel can be optionally mounted to the bracket via a fixed shaft (if present).

[0011] As is well known, a harmonic drive is a transmission mechanism that includes the three components mentioned above. It achieves compactness and lightweight design while maintaining a high transmission ratio, thus meeting the aforementioned requirements. Furthermore, harmonic drives have virtually no backlash, meaning that mounting the stator to the output end will not cause disturbances or noise, and it also has very high positioning accuracy.

[0012] In one particular embodiment, the drive unit further includes an electromagnetic lock arranged to lock the motor, optionally a drum brake, thereby allowing easy remote locking / unlocking of the motor (e.g., via a user interface located next to or on the X-ray system). This facilitates easy switching between manual and automatic modes: in manual mode, the motor is locked, and the entire motor assembly (rotor and stator) moves as a rigid element with the generated motion; in automatic mode, the motor is free to rotate, and the rotor is thus able to generate C-shaped arc motion via a transmission mechanism. It should be noted that in manual mode, when motion is manually applied to the C-shaped arc, the output end of the transmission mechanism becomes the input end, and the input end becomes the locked output end. The drive unit according to the invention provides a reversible solution for easy switching between manual and automatic modes.

[0013] In a more specific example, the electromagnetic lock (EM lock) is mounted on the side of the motor opposite to the output end of the transmission mechanism. This particular side-by-side arrangement (electromagnetic lock—motor—transmission mechanism) results in a generally elongated configuration, primarily a cylindrical configuration with a width close to the width of the motor, thus achieving a very compact configuration. Furthermore, the electromagnetic lock can be mounted or fixed to the yoke 103 facing the motor. In this way, the mounting or fixing is not performed on the bracket, avoiding the need for cumbersome fasteners (such as screws) and vibration damping elements required when mounting the electromagnetic lock to the bracket in this way. Therefore, the arrangement according to this particular embodiment is more compact. Another result of mounting the electromagnetic lock to the yoke is that the electromagnetic lock rotates with the stator along with the C-shaped arc frame—because the stator is also mounted to the output end of the transmission mechanism.

[0014] In a more specific example, the X-ray system further includes a yoke directly mounted to or integrated with the C-shaped frame, wherein the drive unit is mounted to the yoke. Optionally, at least one other drive unit for driving other movements (e.g., angular movements) of the C-shaped frame is embedded in the yoke.

[0015] Specifically, the bracket may be equipped with wheels for movement relative to the ground, thereby making the X-ray system a mobile X-ray system. The term "bracket" should be interpreted broadly as any element within an X-ray system that carries the X-ray system. In a particular example, the bracket may include a frame equipped with wheels for movement, and a more specific C-shaped bracket mounted (optionally rotatably mounted) on the frame. This more specific bracket may incorporate a drive mechanism for translating the C-shaped bracket along a horizontal axis. Attached Figure Description

[0016] The above and other objects, features, and advantages of this disclosure will become clearer from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Several embodiments of this disclosure are illustrated in the drawings by way of non-limiting example.

[0017] Figure 1 A perspective view of an exemplary motor assembly for a C-arm system according to an exemplary embodiment of the present disclosure is shown.

[0018] Figure 2A and Figure 2B A side view and a perspective view of the yoke of a carriage with C-arms are shown.

[0019] Figure 3 A schematic diagram of a propulsion device according to the present disclosure is shown.

[0020] Figures 4A to 4D A schematic diagram, sectional view, front view, and perspective view of the harmonic driver are shown respectively.

[0021] Figure 5 The power transmission path in the harmonic drive is shown in automatic (or electric) mode.

[0022] Figure 6 A detailed longitudinal sectional view of a yoke assembly mounted to a C-arm is shown, the yoke assembly including a propulsion device, a bearing housing, and a yoke sleeve.

[0023] Figure 7A and Figure 7B It shows Figure 6 The side view and longitudinal sectional view of the propulsion device, excluding the yoke sleeve and bearing housing.

[0024] Figure 8A and Figure 8B It shows Figure 7A Two perspective views of the propulsion device, excluding the hollow shaft. For illustrative purposes, the yoke sleeve has been artificially removed (and is considered invisible).

[0025] Figure 8C A perspective view of the motor is shown.

[0026] Figure 9 The middle plate mounted to the bracket is shown. Figure 6 The propulsion device.

[0027] Figure 10 It shows Figure 7B A longitudinal sectional view of the shaft assembly of the propulsion device.

[0028] Figure 11A and Figure 11B They are shown respectively Figure 6Front perspective view and longitudinal sectional view of the hollow shaft-yoke sleeve interface of the propulsion device.

[0029] Figure 12A and Figure 12B An exemplary electromagnetic lock is shown in the corresponding perspective and side view.

[0030] Figure 13 The power transmission path in the harmonic driver in manual mode is shown.

[0031] Figure 14 A schematic diagram showing the installation of a potentiometer onto a propulsion device is shown. Detailed Implementation

[0032] The present disclosure will now be described with reference to various exemplary embodiments illustrated in the accompanying drawings. It should be understood that the description of these embodiments is merely intended to enable those skilled in the art to better understand and further implement the exemplary embodiments disclosed herein, and is not intended to limit the scope of the disclosure in any way. It should be noted that similar or identical reference numerals may be used in the drawings where feasible, and similar or identical reference numerals may denote similar or identical functions.

[0033] As mentioned above, for C-arms, there is a need to design a compact component that is also easy to assemble and disassemble.

[0034] The following text will refer to Figures 1 to 14 The exemplary embodiments are described in more detail, wherein Figure 1 A perspective view of an exemplary X-ray system (also known as a C-arm 100) is shown.

[0035] Figure 1 An exemplary C-arm 100 is depicted, comprising a frame 104 and a C-shaped arc frame 102, each end portion of the C-shaped arc frame 102 carrying an X-ray source and an X-ray detector. The base of the frame 104 may include wheels (or other types of moving elements) to provide a mobile X-ray system 100 for use in hospitals and medical centers. A bracket 101 is provided between the frame 104 and the C-shaped arc frame 102. This bracket may be mounted on or integrated with the frame 104. In certain cases, the bracket 101 is rotatably mounted to the frame 104 about a vertical axis (“Rr”). Additionally or alternatively, the frame 104 and / or the bracket 101 may be provided with a vertical drive to vertically raise and lower the bracket 101 along the vertical axis (“Dh”). The bracket 101 may also have a built-in drive for controlled translation of the C-shaped arc frame 102 along a horizontal axis (“Dh”). Figure 1As shown in Figure 2, the C-shaped arc frame 102 can be mounted to the bracket 101 via the yoke 103 and the propulsion device 130. The yoke 103 is fixedly mounted to the propulsion device 130, and the propulsion device 130 is rotatably mounted to the bracket 101 to drive the C-shaped arc frame 102 to propel a motion “Rp” about a horizontal propulsion axis 1000. The yoke 103 may also have an angle adjustment device (not labeled) built into it (within the internal volume 175), which can drive a rotational motion “Ra” about a horizontal angle axis 2000 via a wheel or roller 109, which is generally orthogonal to the horizontal propulsion axis 1000.

[0036] According to this disclosure, and as Figure 3 As schematically depicted, the propulsion device 30 for driving the rotation Rp of the C-shaped arc frame 102 about the propulsion axis 1000 (also referred to as the "main axis 1000") includes: Motor 10 including rotor 11 and stator 12; A transmission mechanism 20 is arranged to transmit the motion generated by the motor 10 to the C-shaped arc frame 102 that rotates about the main axis 1000.

[0037] The transmission mechanism 20 includes: Input end 21, the rotor 11 is installed (or fixed) to the input end via mechanical connection part 1, and in the unlocked state, the rotor 11 moves according to the rotational motion Rm; The output end 22, stator 12 and C-shaped arc frame 102 are all installed (or fixed) to the output end via corresponding mechanical connection parts 2 and 3, and the C-shaped arc frame 102 and stator 12 move according to the rotational motion Rp.

[0038] The transmission mechanism 20, whose input end 21 and output end 22 are schematically represented by a pinion and a gear respectively, has a predetermined output / input transmission ratio, for example, equal to or less than 1 / 50, or equal to or less than 1 / 100, or equal to or less than 1 / 150, or equal to or less than 1 / 200.

[0039] As is well known, any type of mechanical transmission mechanism 20 can be used, typically a mechanical transmission mechanism using gears.

[0040] As previously described, the C-shaped bracket 102 is mounted to the propulsion device 30, which is rotatably mounted to the bracket 101. Therefore, the bracket 101 can be considered as a support or fixed ground reference for the propulsion motion driven by the propulsion device 30. The mounting of the propulsion device 30 to the bracket 101 can be achieved through a fixed protrusion extending from the bracket 101 through the propulsion device 30. Figure 3(Not shown in the image) This is achieved. The installation can be performed via a transmission mechanism 20, which has portions or ends designed for this assembly with the protrusion. In one particular case, the protrusion is a fixed shaft integral with the bracket 101, or, for example, fixed to a fixed plate of the bracket 101 via a keyless bushing as an intermediate element. In another particular case, a movable shaft ( Figure 3 (Not indicated in the text) can be designed as the mechanical connection 3 between the transmission mechanism 20 and the C-shaped arc frame 102. Preferably, the movable shaft and the fixed shaft are coaxially arranged, wherein one outer shaft is a hollow shaft with an inner cavity for housing another inner shaft within the inner cavity.

[0041] In some exemplary embodiments, the motor 10 may be a brushless motor or a BLDC motor. The rotor 11 may be provided with a motor shaft (not shown), which is configured to cooperate with the input end 21 of the transmission mechanism 20 to transmit the rotational motion generated by the motor 10 to the input end 21. Preferably, a locking mechanism is also provided. Figure 3 (Not shown) to lock the rotation of rotor 11. This locking mechanism is preferably arranged to be remotely triggerable, such as an electromagnetic lock, so that when rotor 11 is locked, the propulsion motion is in manual mode, and when rotor 11 is unlocked, it is in automatic mode (i.e., driven by motor 10). The locking mechanism can be mounted directly or indirectly to stator 12 (e.g., via yoke 103) so that it rotates together with stator 12 and C-shaped arc frame 102 at the same angular velocity. C-shaped arc frame 102 is preferably mounted to the output end 22 of transmission mechanism 20 via yoke 103, which also houses motor 10 and the locking mechanism. Such yoke 103 can be mounted or fixed to the end of the movable shaft.

[0042] Figures 4A to 4D and Figure 5 A harmonic drive 120 (also known as a strain wave gear) is shown as an example of a transmission mechanism. For example, the harmonic drive 120 may be manufactured by Harmonic Drive SE (www.harmonicdrive.de). The harmonic drive includes a wave generator (“WG”) 121, which generally has an elliptical cross-section and is housed within an inner flexure (“FS”) 123. The flexure typically has external teeth on its outer surface, such that when the wave generator rotates, the flexure deforms or moves radially to engage with internal teeth on the inner surface of an outer circular rigid wheel (“CS”) 122.

[0043] The key design feature of this strain wave gear 120 is that the flexure 123 has fewer teeth than the circular rigid wheel 122 (e.g., two fewer teeth). This means that for every full rotation of the wave generator 121, the flexure 123 will need to rotate backward relative to the circular rigid wheel 122 by a small amount (two teeth in this example). Therefore, the rotation of the wave generator 121 causes the flexure 123 to rotate in the opposite direction at a much slower speed. As an alternative embodiment, where the flexure 123 is fixed (mechanically held to the ground) and the circular rigid wheel 122 is free to rotate, the circular rigid wheel 122 rotates forward relative to the flexure 123 by a small amount (two teeth in this example). Therefore, in this alternative embodiment, the rotation of the wave generator 121 causes the circular rigid wheel 122 to rotate in the same direction at a much slower speed.

[0044] The harmonic driver 120 is a two-degree-of-freedom mechanism, similar to a planetary gear system. However, it has three terminals (wave generator 121, flexible wheel 123, and circular rigid wheel 122), of which any two terminals can be selected as input and output terminals, while the third terminal remains fixed.

[0045] In an exemplary embodiment of this disclosure, the C-arm system includes a harmonic driver having three terminals, which are mounted as follows: The wave generator (WG) acts as a terminal of the input 21 and is rigidly connected to the rotor 11, for example, via a keyless bushing.

[0046] The circular rigid wheel (CS) serves as the terminal of the output end 22 and is rigidly connected to the C-shaped arc frame 102 and the stator 12.

[0047] The flexible wheel (FS) is a terminal that is mechanically rigidly connected to the bracket 101, and thus serves as a fixed ground reference for the propulsion device 30.

[0048] Therefore, the flexible wheel is fixed. As another result, the circular rigid wheel rotates in the same direction of rotation as the wave generator (considering the example above, the circular rigid wheel rotates two teeth for every revolution of rotor 11). Thus, contrary to the conventional choice in mechanical design in the field of this invention, the stator (as specified by the conventions of motor manufacturers) is arranged in its environment to rotate in the same manner. Figure 5 As shown, the wave generator (as the input terminal 21) has a rotation generated by the rotor 11. ( For motor m Relative to the ground g The rotation of the circular rigid wheel (as the output end 22) has rotation. ( For the C-shaped arc frame—the propulsion motion p relative to the ground g(rotation), the flexure is fixed, and the harmonic drive is controlled by its reduction ratio. i (For example i =160) definition. As mentioned above, the transmission ratio (or gear ratio) of the harmonic drive output / input (or circular rigid wheel / wave generator) depends directly on the difference in the number of teeth between the flexure and the circular rigid wheel. Note that this is not the gear ratio between the propulsion motion and the motor motion. Since the stator 12 itself is mounted on the output terminal 22 of the harmonic drive 120, since the rotor is mounted on the input terminal of the harmonic drive, and since the flexure of the harmonic drive is connected to the ground (e.g., a fixed ground reference, i.e., a bracket), both the rotor and the stator 12 (i.e., via the harmonic drive 120) rotate. Because: The effective gear ratio between rotor 11 and the propulsion motion is calculated as follows: Figures 6 to 14 A detailed embodiment of the C-arm according to this disclosure is shown.

[0049] The corresponding propulsion device 130 includes a rotor 111 (optionally including a motor shaft 113 extending along the main axis 1000) and a stator 112 of a motor 110 (optionally a brushless DC motor), which, as described above, are respectively mounted (via keyless bushings) to a wave generator (input) 121 and a circular rigid wheel (output) 122 of the harmonic driver 120. A keyless coupling allows the motor 110 to be easily assembled to or removed from the harmonic driver 120. A spacer 129 may also be provided therein. The propulsion device 130 also includes a movable shaft 107, one end of which is also mounted (preferably via a keyless bushing) to the circular rigid wheel 120, preferably on the side opposite to the side on which the stator 112 is mounted on the circular rigid wheel 120, and the other end of which is rotatably mounted to a portion fixed to a bracket 101. The portion fixed to the bracket 101 may be a plate 182 fixed to the bearing housing 105 mentioned later, which has a circular groove or rib in which the rib or groove on one end of the movable shaft 107 is rotatably guided (not shown in the figure). Optionally, an arcuate slide is provided in the groove (not shown in the figure) to provide a rotational stroke greater than 360 degrees (e.g., 400 degrees - i.e., + / - 200 degrees). The sleeve 140 of the yoke 103 of the C-shaped arc bracket 102 is connected via a flange 107-1 extending radially from a section of the movable shaft 107 and a fixing device 141 (e.g., a screw - see Figure 11A-11B It is installed onto the movable shaft 107. More specifically, a clearance 170 can be provided adjacent to the sleeve 107-1 (see...). Figure 7AA complementary ring is arranged in the gap, which is fixed to the yoke sleeve 140 or integrally formed in the yoke sleeve, and then fixed to the flange 107-1 (e.g. Figure 9 or Figure 11B (As shown). Then, the rotating plate 160 can be mounted on the yoke sleeve 140 (see...). Figures 8A-8B Preferably, the rotating plate 160 is used to mount the hollow shaft 107-yoke sleeve 140 assembly to the output end 122 of the transmission mechanism 120 (fixed to the fixing hole 161 provided through the rotating plate 160 by a fixing device—e.g., screws), thereby forming Figure 3 Mechanical connection 3. Optionally, a groove or protrusion (not shown) may be provided on the outer surface of the hollow shaft 107 to assist in the positioning of the yoke sleeve 140 thereon. Furthermore, the outer surface of the fixed shaft 106 may be positioned / aligned relative to the yoke sleeve 140 by means of a pin (or groove) on the yoke sleeve 140 and a groove (or pin) (not shown) on the fixed shaft 106. The yoke sleeve 140 is supported on a bearing housing 105, which is fixed to or integral with the bracket 101 and surrounds a large portion of the movable shaft 107. The bearing housing 105 has a housing into which a set of (tapered) (roller) bearings 191 supported on the outer surface of the movable shaft 107 are embedded. Additionally, a friction pad 192 that contacts the hollow shaft 107 may be provided within the bearing housing 105 to better control the movement of the C-shaped arc frame 102 by limiting movement caused by imbalance (described further below). Additionally, spacers can be provided to fill any remaining gaps, resulting in a final compact and robust assembly and / or providing a motor interface (e.g., between the stator 112 and the circular rigid wheel). The movable shaft 107 is hollow and rotatable about a fixed shaft 106 positioned within the hollow channel of the movable shaft 107, which in turn preferably passes through a keyless bushing 181 at one end (and...). Figure 9 The intermediate plate 182 of the bracket 101 shown is fixed to the bracket 101, and the other end of the fixing shaft 106 (via a flange 106-1 that may extend radially from that end of the fixing shaft 106) is fixed to the bracket 101. Figure 7BThe flexible wheel 123 (shown) is fixed to the harmonic drive 120. Radial backlash in the mechanism is eliminated by using this keyless bushing 181. Therefore, the fixed shaft 106 serves as the fixed ground reference for the harmonic drive 120. The fixed shaft 106 extends along the propulsion axis 1000 (around which the C-shaped arc frame propels). In this configuration of the C-shaped arc frame assembly, the yoke 103 is suspended on a (tapered roller) bearing 191. Components in the load path bear significant loads, which may be critical from a structural safety perspective. The bearing 191, positioned between the movable shaft 107 and the fixed shaft 106, alleviates the load about the main axis 1000, while the friction pad 192 compensates for the lateral loads (lateral to the main axis 1000—causing the aforementioned "imbalance") resulting from the center of gravity of the yoke 103—C-shaped arc frame 102 assembly deviating from the main axis 1000. Cable 108, such as a spiral cable, is optionally arranged in a gap 109 extending between the movable shaft 107 and the fixed shaft 106. Cable 108 is connected to a motor and / or locking mechanism and / or other electrical components for propulsion and / or angular motion, for power supply and / or data communication and / or feedback.

[0050] Alternatively, the propulsion system includes a locking mechanism comprising an electromagnetic lock ("EM lock") 150 fixed to an assembly consisting of a stator 111, a yoke 103, a circular rigid wheel 122, and a movable shaft 107. Optionally, the EM lock (either directly or via an optional attachment element 140-1 fixed to the end portion of the yoke sleeve 140) is fixed to the yoke sleeve 140. Thus, the electromagnetic lock 150 rotates with the yoke 103 about the propulsion axis 1000. The electromagnetic lock 150 includes a fixed element (e.g., the electromagnetic lock housing 151) and a movable element (friction disc 152) movable along the main axis 1000, and is arranged such that: when the electromagnetic lock 150 is energized (or not energized, depending on the type of electromagnetic lock 150), the movable element 152 is in contact with the rotor 111 of the motor 110—a locked state; and when the electromagnetic lock 150 is not energized (or energized, depending on the type of electromagnetic lock 150), the movable element 152 is not in contact with the rotor 111—an unlocked state. Optionally, a locking drum 155 is provided between the electromagnetic lock 150 and the motor 110.

[0051] This electromagnetic lock 150 allows switching between a manual mode in the locked state and an automatic (or electric) mode in the unlocked state. It should be noted that in manual mode, the C-shaped arc frame is manually moved, the output end of the transmission mechanism 120 (i.e., the circular rigid wheel 122 of the harmonic driver 120) becomes the input end of the transmission mechanism 120, and the input end (i.e., the wave generator 121 of the harmonic driver 120) becomes the output end of the transmission mechanism 120, which rotates at the same speed as the circular rigid wheel 122. The flexible wheel 123 is also an output end (ideally, it should remain fixed). In this manual mode, the fixed shaft 106 (connected to the flexible wheel) bears the maximum torque during manual mode—this is subject to overload conditions. In fact, in the locked state, the (manual) external torque load is primarily transmitted to the fixed shaft 106 via the harmonic driver 120 (from the circular rigid wheel 122 to the flexible wheel 123) and slips through the keyless bushing 181 of the fixed shaft 106. Figure 13 The corresponding power transmission path in the harmonic drive 120 in this manual mode is shown: there are two main loads: inertial load 195 and frictional load (mainly through friction pad 192), which the motor 110 must overcome to do work. In manual mode, the fixed shaft 106 provides a ground reference for the harmonic drive 120 and connects the flexible wheel (FS) 123 to the intermediate plate 182 via a keyless bushing 181. Therefore, under this overdrive condition, the fixed shaft 106 experiences maximum torque. τ FS The circular rigid wheel 122 (attached to the yoke sleeve 140) serves as the input end (manual torque). τ ext Since the electromagnetic lock 180 is in the locked mode, the wave generator 121 is also fixed. Under this locked condition, if the locking device does not slip, the harmonic driver 120 is fully locked during over-control (or manual use). In summary, as described above, Figure 13 As shown, external torque τ ext It is directly transmitted to the fixed shaft 106.

[0052] The potentiometer assembly 185 for propulsion can be further secured to the bracket 101 (e.g., as shown in the image). Figure 9 As shown, the intermediate plate 182, which is fixed to or integral with the bracket 101, is placed on the back side and arranged in conjunction with the movable shaft 107 to measure the angular position of the C-shaped arc frame 102. In particular, the gear 183 of the potentiometer 180 can mesh with the gear 171 disposed around the end of the movable shaft 107 through a hole through the intermediate plate. Figure 14This mounting method is illustrated schematically. It should be noted that potentiometer 180 is primarily used for homing (or initiating system positioning). After homing, if the encoder resolution is higher than the potentiometer 180 resolution, the position is preferably tracked by the encoder connected to motor 110.

[0053] A thruster position indicator 200 can be added to the outer surface of the yoke sleeve 140 and / or the outer surface of the bearing housing 105 to assist the user in angularly positioning the C-shaped arc frame 102 according to the thrust position. For example, the indication range can be -90° to 0 to 90°.

[0054] A method for removing the motor 110 from the C-arm assembly is proposed, comprising the following sequential steps: removing... C-shaped arc frame 102, Retainers for the yoke sleeve 140 and the C-shaped arc frame roller 109. Electromagnetic lock 150, Keyless bushing 181, Motor 110 connector, Rotating plate 160 (from yoke sleeve 140). Motor-side spacer 129, Remove the motor 110 and locking drum 115 from the motor side spacer 129 (the motor 110 and locking drum 115 can be an integrated component and can be replaced as a whole).

[0055] This method eliminates the need to remove the hollow shaft 107, bearing housing 105, or any other core component of the propulsion device 130 to replace the motor 110. This is clearly an improvement compared to other types of components. This is primarily due to the fact that most of the core components of the propulsion device 130 are mounted on the transmission mechanism 120.

[0056] A method for removing the electromagnetic lock 150 from the C-arm assembly is now proposed, the method comprising the following sequential steps: Removal: C-shaped arc frame 102, Retainers for the yoke sleeve 140 and the C-shaped arc frame roller 109. Electromagnetic lock 150.

[0057] Although the invention has been illustrated and described in detail in the accompanying drawings and foregoing description, such illustrations and descriptions should be regarded as illustrative or exemplary, and not restrictive; the invention is not limited to the disclosed embodiments.

[0058] For example, the invention can be implemented in an embodiment where the transmission mechanism does not use the harmonic driver 120, but rather any other type of transmission mechanism capable of applying a modified (preferably reduced) propulsion speed from the motor output to the C-shaped frame 102, such as a transmission mechanism with only two terminals (one input and one output, connected to the rotor, stator, and movable shaft for implementing the system according to this disclosure), like a planetary gear. Furthermore, this disclosure is not limited to the aforementioned coaxial shaft arrangement; for example, it can use an internal movable shaft and an external fixed shaft. More broadly, any other arrangement can be designed as long as the propulsion device is held primarily by the transmission mechanism on the one hand, and the C-shaped frame 102 is propelled at a speed modified from the motor speed on the other. Additionally, any type of locking mechanism can be used instead of the aforementioned drum lock, as long as the locking mechanism can lock and unlock the motor or the motor-driven components. Similarly, control of the movement of the C-shaped frame 102 does not necessarily include a potentiometer and / or an encoder mounted on the motor, but can include any measuring tool that can assist in achieving better control.

[0059] By studying the accompanying drawings, this disclosure, and the appended claims, those skilled in the art will be able to understand and implement other variations of the disclosed embodiments in practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude plural forms. A single processor or other unit may perform the functions of several items recited in the claims. The fact that certain technical means are recited in different dependent claims does not in itself imply that combinations of these technical means cannot be used advantageously. Computer programs may be stored / distributed on suitable media, such as optical storage media or solid-state media provided together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems. Any reference numerals in the claims should not be construed as limiting the scope of protection.

Claims

1. An X-ray system (100), comprising: The C-shaped arc frame (102) is equipped with or will be equipped with an X-ray source and an X-ray detector. The bracket (101) of the C-shaped arc frame (102) is adapted to hold the C-shaped arc frame (102). Drive unit (30, 130) for driving the C-shaped arc frame (102) to rotate about the main axis (1000), the drive unit comprising: The motor (10, 110) includes a rotor (11, 111) and a stator (12, 112). The transmission mechanism (20, 120) includes: The first terminal of the input terminal (21) is installed to the rotor (11). A second terminal defining an output end (22) is mounted to the stator (12) and the C-shaped arc frame (102), and a third terminal for mounting to a fixed ground reference, wherein the transmission mechanism is arranged to transmit the motion generated by the motor (10, 110) to the C-shaped arc frame (102) rotating about the main axis (1000) at a predetermined transmission ratio from the input end to the output end of the transmission mechanism.

2. The X-ray system (100) according to claim 1, wherein, The transmission mechanism (20, 120) includes a harmonic driver (120), the harmonic driver comprising: The wave generator (121) is for the first terminal. The second terminal is a circular rigid wheel (122). The flexible wheel (123) of the third terminal is wherein the fixed ground reference is preferably defined by the bracket (101).

3. The X-ray system (100) according to any one of the preceding claims, wherein, The transmission mechanism (20, 120) includes: The rotatable shaft (107) is mounted on the C-shaped arc frame (102) and the output end (22). The fixed shaft (106) of the transmission mechanism (20, 120) is mounted on the bracket (101) to hold it in place.

4. The X-ray system (100) according to claim 3, wherein, The rotatable shaft and the fixed shaft (107, 106) are coaxially arranged around the main axis (1000).

5. The X-ray system (100) according to claim 3 or 4, wherein, The rotatable shaft (107) has an inner cavity extending along the main axis (1000), and at least a portion of the fixed shaft (106) is disposed within the inner cavity.

6. The X-ray system (100) according to claim 5, wherein, The fixed shaft (106) is fixed to the bracket (101) by a keyless bushing (181), and optionally fixed to the bracket by an intermediate support (182) on which a potentiometer (180) is disposed, the potentiometer (180) engaging with the hollow shaft (107).

7. The X-ray system (100) according to any one of claims 4 to 6, wherein, A cable (108) is provided between the rotatable shaft (107) and the fixed shaft (106), optionally the cable is a spiral cable (108), and optionally the spiral cable (108) is arranged to supply power to the motor (110).

8. The X-ray system (100) according to any one of the preceding claims, wherein, The transmission mechanism (20, 120) has a transmission ratio equal to or less than 1 / 100.

9. The X-ray system (100) according to any one of the preceding claims, wherein, The flexible wheel is mounted to the bracket (101) via the fixed shaft (106).

10. The X-ray system (100) according to any one of the preceding claims further includes an electromagnetic lock (180) arranged to lock the motor (10, 110), optionally the electromagnetic lock (180) being a drum brake.

11. The X-ray system (100) according to any one of the preceding claims, wherein, The electromagnetic lock (180) is installed on the side of the motor (10, 110) opposite to the output end of the transmission mechanism (20, 120).

12. The X-ray system (100) according to any one of the preceding claims further includes a yoke (103) directly mounted to or integral with the C-shaped arc frame (102), wherein the drive device (30, 130) is mounted to the yoke (103) and optionally mounted together with at least another drive device (30, 130) for driving other movements of the C-shaped arc frame (102).

13. The X-ray system (100) according to any one of the preceding claims, comprising a spacer (129) and / or a keyless bushing (181) for holding the drive unit (30, 130) in a fixed and stable position within the housing even when the X-ray system (100) is moved.

14. The X-ray system (100) according to any one of the preceding claims, wherein, The bracket (101) may optionally be provided with wheels by means of a frame (104) holding the bracket (101) for movement relative to the ground.

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