Gravity balance mechanism, trolley base and surgical robot

Abstract

The invention discloses a gravity balance mechanism, a trolley base and a surgical robot, and relates to the technical field of mechanical equipment.The balance mechanism is assembled between a static part and a moving part and comprises a crank mechanism with one end connected to the static part, and the output end of the crank mechanism is connected with the moving part; one end of the force providing mechanism is connected to the static part, and the other end is butted with the input end of the crank mechanism; the force providing mechanism is configured to provide linearly changing force for the crank mechanism, so that the output end of the crank mechanism applies acting force opposite to the gravity of the moving part to the moving part under the condition that the crank mechanism transmits the linearly changing force. By means of the crank mechanism, linear change force is converted into constant output pulling force of the sliding block, almost constant balance force is achieved, the sliding block can output balance force of different magnitudes by adjusting different rod lengths of the crank mechanism, different gravity balance requirements are better met, universality is high, and the application range is wide. And the whole life cycle of the equipment can be met.

Description

[0001] This application is a divisional application of the Chinese invention patent application "A gravity balancing mechanism, trolley base and surgical robot" with application number 202310728343.9 filed on June 19, 2023. Technical Field

[0002] The present invention relates to the technical field of mechanical equipment, and in particular to a gravity balancing mechanism, a trolley base and a surgical robot. Background Art

[0003] With the continuous development of medical devices, computer technology, and control technology, minimally invasive surgery has become increasingly widely used due to its advantages such as minimal surgical trauma, short recovery time, and reduced patient pain. Minimally invasive surgical robots, with their high dexterity, high control precision, and intuitive surgical images, can avoid operational limitations such as hand tremors during filtering operations, making them widely applicable to surgical areas such as the abdominal, pelvic, and thoracic cavities.

[0004] Currently, minimally invasive surgical robots consist of a main control console and a slave manipulator arm. The main control console collects the doctor's operating signals, which are processed by the control system and then generate control signals for the slave manipulator arm, which then performs the surgical operation. The main control console can be deployed by manually pushing it. When pushing the main control console, to ensure that the main control console can pass through certain terrains, there needs to be a certain height difference between the console's universal casters and the lowest point of its chassis. After the main control console is deployed in place, the universal casters need to be locked to provide a more stable operating platform. At the same time, the pedal base, which is equipped with various control foot switches, needs to be lowered to the ground to make it more comfortable for the surgeon to use their feet. Since the pedal base has a certain weight, a gravity balancing mechanism is required to make it easier to control its rise. However, the space on the base is limited, so the volume of the gravity balancing mechanism is required to be relatively high.

[0005] Chinese utility model patent CN217793334U discloses a doctor control platform, which includes a doctor trolley frame, a main operating arm installed on the doctor trolley frame and a display unit with adjustable height; the main operating arm is used by the doctor to operate to control the instrument to complete the operation; a trolley base is installed at the bottom of the doctor trolley frame; the doctor trolley frame includes an armrest, a column, a side push handle assembly and a fixing frame; two side push handle assemblies are arranged on the same side of the armrest; one end of the two side push handle assemblies is respectively connected to the end of the corresponding armrest, and the other end of the two side push handle assemblies is connected to the fixing frame; the display unit and / or the fixing frame are slidably connected to the side of the column. Among them, a solution for achieving gravity balance by setting up multiple balancing components is also disclosed, but the elastic component in this solution uses a constant force spring. The standard constant force spring on the market provides a standard constant tension, and the constant tension is relatively small. In the gravity balancing mechanism, the gravity to be balanced is large, so the structure uses two groups on each side, a total of eight constant force springs; and the constant tension of the standard constant force spring has a certain gradient, and it is difficult to better match the gravity to be balanced, and it is difficult to make the two exactly equal, unless the constant force spring is customized according to the gravity to be balanced, but the cost of customized constant force springs is high; and, since the balanced gravity is large, the constant force spring that provides a large constant tension generally has a short lifespan, which cannot cover the full life cycle of the equipment, so the structure needs to be replaced regularly, causing inconvenience. Summary of the Invention

[0006] In response to the problems existing in the prior art, the present invention provides a gravity balancing mechanism, a trolley base and a surgical robot.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] In a first aspect, a gravity balancing mechanism is provided, which is assembled between a stationary component and a moving component and is configured to balance the gravity of the moving component, comprising: a crank mechanism, one end of which is connected to the stationary component, and the output end of the crank mechanism is connected to the moving component; a force providing mechanism, one end of which is connected to the stationary component, and the other end of the force providing mechanism is connected to the input end of the crank mechanism, and the force providing mechanism is configured to provide a linearly changing force to the crank mechanism, so that when the crank mechanism transmits the linearly changing force, the output end of the crank mechanism applies a force opposite to the gravity of the moving component to the moving component.

[0009] Based on the above technical solution, further, the stationary component includes a base; the crank mechanism includes a telescopic arm assembly, one end of the force providing mechanism is arranged on the base, and the other end of the force providing mechanism is docked with the input end of the telescopic arm assembly to apply a linearly changing force to the input end.

[0010] Based on the above technical solution, further, the telescopic arm assembly includes: a first telescopic arm, one end of which is hinged to the base; a second telescopic arm, one end of which is hinged to the other end of the first telescopic arm, and the hinge point between the second telescopic arm and the first telescopic arm can move relative to the base; the other end of the second telescopic arm is connected to the moving part.

[0011] Based on the above technical solution, further, the crank mechanism also includes an output slider, which is connected between the second telescopic arm and the moving part, the second telescopic arm is hinged to the output slider, and the hinge point between the second telescopic arm and the output slider can rotate relative to the base; a fixed part is provided on the base, and the first telescopic arm is hinged to the fixed part.

[0012] Based on the above technical solution, further, a fixing portion is provided on the base, and the first telescopic arm is connected to the base via the fixing portion.

[0013] Based on the above technical solution, further, the gravity balancing mechanism also includes a guide mechanism, the guide mechanism includes a guide column, and the guide column is installed on the base; the force providing mechanism is an elastic member, and the elastic member is sleeved on the guide column.

[0014] Based on the above technical solution, further, the guide mechanism also includes a guide rod installed on the base; a guide block, sleeved on the guide rod, and the guide block is configured to move along the guide rod; the guide column and the elastic member are inserted into the guide block, and an avoidance groove is also provided at the bottom of the guide block, and the crank mechanism moves below the avoidance groove.

[0015] Based on the above technical solution, further, at least one second guide hole is provided on the guide block, one end of the guide rod is fixed to one side of the base, the other end of the guide rod passes through the second guide hole and is fixed to the other side of the base, and an oil-free bushing is also provided on the guide rod, and the oil-free bushing is located in the second guide hole.

[0016] Based on the above technical solution, further, the interior of the base is a groove structure, the guide mechanism is located in the groove, and a first through hole is opened on the base, a first guide hole is opened on the guide block, and the guide column extends from the outside of the base through the first through hole to the inside of the groove until it is inserted into the first guide hole. A second through hole is also opened on the base, and one end of the first telescopic arm is connected to a bearing, and the bearing is located in the second through hole.

[0017] In a second aspect, a trolley base is provided, comprising the gravity balancing mechanism provided in the first aspect, wherein the stationary component comprises a base frame, and the moving component comprises a control pedal.

[0018] In a third aspect, a surgical robot is provided, comprising the trolley base provided in the second aspect.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects:

[0020] This invention uses a crank mechanism to convert a linearly varying input force into a slider's output tension. Through design and calculation, a specific rod length can be matched to a specific scenario. This allows the linearly varying elastic force to be converted into a nearly constant output tension at the output slider. The error can currently be controlled within 5%, allowing it to be used to provide gravity balancing for components connected to the output slider. Compared to existing technologies, this crank mechanism not only achieves a nearly constant balancing force, but also allows the slider to output varying balancing forces by adjusting the crank mechanism's rod lengths, better meeting varying gravity balancing requirements. This provides high versatility and the ability to meet the full lifecycle of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A perspective view of the gravity balancing mechanism of the present invention from the front end perspective;

[0022] Figure 2 for Figure 1 AA section view;

[0023] Figure 3 It is a structural diagram of the gravity balance mechanism of the prior art;

[0024] Figure 4 A perspective view of the gravity balancing mechanism of the present invention from the rear end perspective;

[0025] Figure 5 for Figure 3 BB cross-sectional view;

[0026] Figure 6 Schematic diagram of the structure of the base in the gravity balancing mechanism of the present invention;

[0027] Figure 7 for Figure 6 A schematic diagram of the structure of the relative angles of the base;

[0028] Figure 8 This is a structural diagram of the gravity balancing mechanism of the present invention with the base hidden;

[0029] Figure 9 This is a structural diagram of the gravity balance mechanism of the present invention in a retracted state;

[0030] Figure 10 This is a structural diagram of the gravity balance mechanism of the present invention in an extended state;

[0031] Figure 11 It is a structural schematic diagram of the guide block of the present invention;

[0032] Figure 12 for Figure 11 A schematic diagram of the structure of the relative angles of the middle guide block;

[0033] Figure 13 A simple diagram of the telescopic process of the telescopic arm assembly of the present application;

[0034] Figure 14 A diagram of the balancing force without considering friction in Embodiment 1 of the present application;

[0035] Figure 15 A zoomed-in view of the longitudinal coordinate of Figure 14 ;

[0036] Figure 16 A diagram of the balancing force considering friction in Embodiment 1 of the present application;

[0037] Figure 17 A zoomed-in view of the longitudinal coordinate of Figure 16 ;

[0038] Figure 18 A simple diagram of the spring force and the force direction of the output slider being not perpendicular to each other in Embodiment 2 of the present application;

[0039] Figure 19 A structural diagram of the trolley base of the prior art in Embodiment 3 of the present application;

[0040] The reference signs: 1. first telescopic arm; 2. second telescopic arm; 3. output slider; 4. elastic member; 5. base; 6. fixed hinge; 7. movable hinge; 8. guide post; 9. guide block; 10. guide rod; 11. first guide hole; 12. second guide hole; 13. avoiding groove; 14. fixed plate; 15. bearing; 16. sleeve without lining; 17. fixed part; 18. first via hole; 19. second via hole; 20. spring pin; 21. constant force spring; 22. spring mounting base; 23. control pedal. DETAILED DESCRIPTION

[0041] The present application will be further described and illustrated in conjunction with the drawings and specific embodiments. The technical features of each embodiment of the present application can be combined accordingly without conflict.

[0042] In order to make the above-mentioned objects, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application will be described in detail below in conjunction with the drawings. In the following description, a lot of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, so the present application is not limited by the specific embodiments disclosed below. The technical features of each embodiment of the present application can be combined accordingly without conflict.

[0043] In the description of the present invention, it should be understood that when an element is considered to be "connected" to another element, it can be directly connected to the other element or indirectly connected, that is, there are intermediate elements. On the contrary, when an element is said to be "directly" connected to another element, there are no intermediate elements.

[0044] In the description of the present invention, it should be understood that the terms "first" and "second" are used solely for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly specifying the number of technical features being described. Therefore, features defined as "first" or "second" may explicitly or implicitly include at least one of such features.

[0045] Example 1

[0046] like Figure 1-Figure 5 As shown, a gravity balancing mechanism is assembled between a stationary part and a moving part for balancing the gravity of the moving part, comprising a crank mechanism and an elastic member 4. One end of the crank mechanism and one end of the elastic member 4 are both fixed to the stationary part, and the other end of the elastic member 4 is connected to the input end of the crank mechanism to apply a linearly changing force to the crank mechanism. The output end of the crank mechanism is connected to the moving part. The crank mechanism transmits a linearly changing force so that the output end applies a force to the moving part in the opposite direction to the gravity of the moving part.

[0047] Specifically, the stationary part includes a base 5, combined with Figure 6 and Figure 7 As shown, the crank mechanism includes a telescopic arm assembly, one end of an elastic member 4 is fixed to a base 5, and the other end of the elastic member 4 is connected to the input end of the telescopic arm assembly to apply a linearly varying force to the input end. The telescopic arm assembly includes a first telescopic arm 1, a second telescopic arm 2, and an output slider 3. A fixed portion 17 is provided on the base 5. One end of the first telescopic arm 1 is connected to the base 5 via the fixed portion 17 on the base 5 via a fixed hinge 6. The other end of the first telescopic arm 1 is connected to one end of the second telescopic arm 2 via a movable hinge 7. The other end of the second telescopic arm 2 is connected to a moving component. The second telescopic arm 2 is connected to the moving component via the output slider 3, and the second telescopic arm 2 is connected to the output slider 3 via the movable hinge 7. In other words, the first telescopic arm 1, the second telescopic arm 2, and the output slider 3 can all rotate about their respective mounting hinges, while the output slider 3 can only move linearly up and down relative to the base 5. The "fixed" and "movable" terms of the hinge refer to whether its position relative to the base 5 changes.

[0048] Furthermore, the gravity balancing mechanism also includes a guide mechanism, combined with Figure 11 and Figure 12As shown, the guide mechanism includes a guide column 8, a guide block 9 and a guide rod 10, the guide column 8 is installed on the base 5, and the guide column 8 is sleeved with an elastic element 4, which is a spring capable of providing a linearly changing force. Specifically, a common compression spring is used in this embodiment. The guide rod 10 is installed on the base 5, the guide block 9 moves along the guide rod 10, and the guide column 8 and the elastic element 4 are jointly inserted into the guide block 9, wherein the guide rod 10 is at least one. The inside of the base 5 is a groove structure, the guide mechanism is located in the groove, and the base 5 is provided with a first through hole 18 and a second through hole 19, the position of the second through hole 19 is also provided with a bearing 15, the bearing 15 is rotatably connected with one end of the first telescopic arm 1, the guide block 9 is provided with a first guide hole 11 and at least one second guide hole 12, the guide column 8 extends from the outside of the base 5 to the inside of the groove through the first through hole 18, and is inserted into the first guide hole 11, one end of the guide rod 10 is fixed with one side of the base 5, the other end of the guide rod 10 passes through the second guide hole 12 and is fixed with the other side of the base 5 through the fixed plate 14, the guide rod 10 is also sleeved with an oil-free bushing 16, the oil-free bushing 16 is located in the second guide hole 12, and through the oil-free bushing 16, the guide block 9 can smoothly slide in the base 5 along the at least one guide rod 10. The guide block 9 is also provided with an avoiding groove 13 below the crank mechanism, the avoiding groove 13 is provided on one side to reduce the weight of the gravity balance mechanism itself, and on the other side to facilitate the crank mechanism to be accommodated in the avoiding groove 13 when retracted, so as to avoid unnecessary interference between the crank mechanism and the bottom of the guide block 9 when retracted, and thus the size of the entire mechanism in the height direction can be reduced.

[0049] Specifically, the working principle of the gravity balance mechanism is: Figures 8-10 As shown, the force generated by the compression spring pushes the guide block 9, so that the guide block 9 presses the end of the first telescopic arm 1 provided with the bearing 15, at this time, the spring will give the first telescopic arm 1 a rotating torque, which will drive the output slider 3 to move upward through the crank mechanism, so that the output slider 3 always provides an upward pulling force. By selecting appropriate rod length, the output slider 3 can provide an approximately constant upward pulling force within the full stroke range.

[0050] Specifically, in combination with Figure 13As shown, when designing and calculating the rod length, auxiliary software such as Metalab can be used to perform force analysis and fitting calculations on the crank mechanism and spring. For example, if the output slider 3 is required to provide an approximately constant force F, the tension is applied to the end of the output slider 3. At this time, the force analysis of the crank mechanism is performed, and the expression f(F) for the torque applied to the first telescopic arm 1 by the force is listed. At the same time, a more suitable standard compression spring is selected, and the expression f(spring) for the torque applied by the spring to the first telescopic arm 1 is listed. The calculation involves several parameters, such as the main rod length L1 of the first telescopic arm 1, the main rod length L2 of the second telescopic arm 2, the length L3 of one end of the clamping guide block 9 in the first telescopic arm 1, the rod length L3 of the clamping guide block 9 in the first telescopic arm 1, the angle θ between the rod and the perpendicular line of the main rod length L1 of the first telescopic arm 1, and the installation position S of the spring on the base 5. During design, these five values ​​can be used as independent variables to programmatically calculate the absolute value of the difference between f(F) and f(spring) within the full range of travel to minimize it, thereby determining the rod length and spring installation position of each telescopic arm. Of course, the entire analysis and calculation involves more parameters than those listed above. Those skilled in the art will appreciate that other values ​​can also be used as independent variables to perform the analysis and calculation based on structural design needs.

[0051] Specifically, combined Figure 13 As shown, when the spring expands and contracts horizontally, the elastic force it provides varies linearly. To ensure that the tension applied to the output slider 3 is approximately constant, specific parameters such as rod length and angle are designed. When the given input parameters vary, the resulting structure will also change, and is not limited to the configurations listed in this embodiment. After the spring is selected, the configuration presented in this embodiment is based on the following input parameters: the distance T from the spring end to the surface of the bearing 15, the diameter D of the bearing 15, Y (the vertical distance between the center of the dynamic hinge 7 on the output slider 3 and the center of the fixed hinge 6 within the full travel range, which can also be understood as the initial position Y1 and the end position Y2), and LX (the horizontal distance between the two). The remaining five parameters are calculated: the main rod length L2 of the second telescopic arm 2, the main rod length L1 of the first telescopic arm 1, the length L3 of one end of the compression guide block 9 in the first telescopic arm 1, the angle θ between the vertical line of the main rod length L1 of the first telescopic arm 1, and the spring installation position S on the base 5. The horizontal distance from the spring's head end to the center of the fixed hinge 6 represents the spring installation position. The error of the result obtained in this embodiment is within 5%, which can meet the needs of gravity balance. Generally, those skilled in the art will first complete the spring selection, and then use at least Y and LX as input parameters. Of course, the characteristics of the spring can also be used as the calculation quantity, but this may occur in existing products on the market. It is impossible to select a spring with the calculated characteristics, and customization is required, thereby increasing the cost of the equipment. Combined with Figure 14-17 As shown, Figure 14 This is a schematic diagram of the balancing force without considering friction in Example 1 of the present invention; Figure 15 for Figure 14 The vertical axis enlarged graph; Figure 16 This is a schematic diagram of the balancing force in consideration of friction in Example 1 of the present invention; Figure 17 for Figure 16 The vertical axis enlarged diagram; set the expected balance force to 18kgf, through Figure 14 and Figure 15 As can be seen, the balancing force in the figure, without considering friction, varies between 17.9kgf and 18.1kgf. Compared to the desired 18kgf, the error is very small, only 0.55%, which meets the corresponding requirements. When considering the balancing force for reciprocating motion with friction, the balancing force in the figure varies between 17.6kgf and 18.4kgf, with an error of 2.2%, which also meets the corresponding requirements.

[0052] Example 2

[0053] Different from Example 1, Figure 18 As shown, the relative directions of the spring force and the force of the output slider 3 in this embodiment are no longer perpendicular, and can be parallel, for example. Of course, any other angle is possible, as long as space permits. The spring applies a downward force, which, through the conversion of the telescopic arm, will provide an upward force to the output slider 3. It will be understood that this embodiment is an exemplary illustration of the positional relationship between the spring force and the output slider, and is not limited to perpendicular or parallel relationships. Of course, the crank mechanism is not limited to having only two telescopic arms, but the structure of two telescopic arms is the simplest, and the analysis and fitting calculations are also simple.

[0054] Example 3

[0055] Based on the gravity balance mechanism of embodiment 1, different from Figure 19 The schematic diagram of the structure of a conventional trolley base is shown. A trolley base is implemented, wherein the stationary component includes a base frame, which is mounted on the trolley base, and a gravity balancing mechanism. The moving component includes a control pedal 23, which is mounted on the trolley base. This trolley base has the same technical effects as Example 1.

[0056] Example 4

[0057] Based on the trolley base of Example 3, a surgical robot is implemented, which also has the same technical effects as Example 3.

[0058] Finally, it should be noted that the above is only to illustrate the technical solutions of the present application, and is not a limitation on the scope of protection of the present application, and simple modifications or equivalent replacements of the technical solutions of the present application by those skilled in the art do not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A gravity balancing mechanism, mounted between a stationary component and a moving component, configured to balance the gravity of the moving component, characterized in that: include: a crank mechanism, one end of which is connected to the stationary component, and an output end of the crank mechanism is connected to the moving component; A force providing mechanism, one end of which is connected to the stationary component, and the other end of which is connected to the input end of the crank mechanism. The force providing mechanism is configured to provide a linearly changing force to the crank mechanism so that when the crank mechanism transmits the linearly changing force, the output end of the crank mechanism applies a force opposite to the gravity of the moving component to the moving component.

2. The gravity balancing mechanism according to claim 1, characterized in that: The stationary component includes a base; the crank mechanism includes a telescopic arm assembly, one end of the force providing mechanism is provided on the base, and the other end of the force providing mechanism is docked with the input end of the telescopic arm assembly to apply the linearly changing force to the input end.

3. The gravity balancing mechanism according to claim 2, characterized in that: The telescopic arm assembly comprises: a first telescopic arm, one end of which is hinged to the base; The second telescopic arm has one end hinged to the other end of the first telescopic arm, and the hinge point between the second telescopic arm and the first telescopic arm can move relative to the base; the other end of the second telescopic arm is connected to the moving component.

4. The gravity balancing mechanism according to claim 3, characterized in that: The crank mechanism further includes an output slider, the output slider being connected between the second telescopic arm and the moving component, the second telescopic arm being hinged to the output slider, and the hinge point between the second telescopic arm and the output slider being rotatable relative to the base; A fixing portion is provided on the base, and the first telescopic arm is hinged to the fixing portion.

5. The gravity balancing mechanism according to claim 2, characterized in that: It also includes a guide mechanism, the guide mechanism includes a guide column, and the guide column is installed on the base; The force providing mechanism is an elastic member, and the elastic member is sleeved on the guide column.

6. The gravity balancing mechanism according to claim 5, characterized in that: The guide mechanism further comprises: A guide rod is mounted on the base; a guide block, sleeved on the guide rod, the guide block being configured to move along the guide rod; The guide column and the elastic member are inserted into the guide block. The bottom of the guide block is further provided with an avoidance groove, and the crank mechanism moves below the avoidance groove.

7. The gravity balancing mechanism according to claim 6, characterized in that: At least one second guide hole is also provided on the guide block, one end of the guide rod is fixed to one side of the base, the other end of the guide rod passes through the second guide hole and is fixed to the other side of the base, and an oil-free bushing is also provided on the guide rod, and the oil-free bushing is located in the second guide hole.

8. The gravity balancing mechanism according to claim 5, characterized in that: The interior of the base is a groove structure, the guide mechanism is located in the groove, and a first through hole is provided on the base, a first guide hole is provided on the guide block, the guide column extends from the outside of the base through the first through hole to the inside of the groove until it is inserted into the first guide hole, and a second through hole is also provided on the base, one end of the first telescopic arm is connected to a bearing, and the bearing is located in the second through hole.

9. A trolley base, characterized in that: It comprises the gravity balancing mechanism according to any one of claims 1 to 8, wherein the stationary component comprises a base frame, and the moving component comprises a control pedal.

10. A surgical robot, characterized in that: Including the trolley base according to claim 9.

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