Dual parallelogram RCM mechanism and minimally invasive surgical robot having same

Abstract

The present application relates to a kind of double parallelogram RCM mechanism and minimally invasive surgery robot with the mechanism, which includes with stop rotary joint and double parallelogram linkage;The input end and the output end of double parallelogram linkage are respectively associated with stop rotary joint and surgical execution mechanism, so that the axis of surgical execution mechanism always passes through the RCM point of double parallelogram linkage;First locking mechanism is provided between with stop rotary joint and double parallelogram linkage, and second locking mechanism is provided on at least one articulated joint of double parallelogram linkage.The robot includes the above-mentioned double parallelogram RCM mechanism and surgical execution mechanism, and surgical execution mechanism includes linear module, unlocking handle and surgical tool, linear module is arranged on the output end of double parallelogram linkage, and surgical tool can be translated along linear module, to approach or away from surgical incision through the RCM point of double parallelogram linkage.The present application has stronger practicability, operability and safety compared with the traditional RCM mechanism.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of mechanical equipment, specifically about a kind of double parallelogram RCM mechanism and the minimally invasive surgical robot with the mechanism. BACKGROUND

[0002] At present, minimally invasive surgical robot has been widely used to help doctors complete more delicate surgery, not only can assist to reduce the workload of doctors, while it can reduce the influence caused by fatigue or hand tremor when the doctor operates, in addition, it also has the advantages of small surgical injury, fast healing etc.. For example, the da Vinci minimally invasive surgical robot system (da Vinci Surgery Robot System) of the United States has been widely used in clinical.

[0003] In laparoscopic minimally invasive surgical robot technology, an extremely important part is its RCM (Remote Center of Motion, remote center of motion) mechanism. The role of RCM mechanism is to provide a remote center of motion point, which can always coincide with the minimally invasive surgical incision, and can ensure that the surgical instruments and the surgical incision of the patient do not pull during the minimally invasive surgery, so as to ensure the safety of surgery. Because the characteristics of RCM mechanism are exactly the same as the operation characteristics of minimally invasive surgery, it has achieved great success in minimally invasive surgical robot.

[0004] The current mainstream minimally invasive surgical robot RCM mechanism adopts double parallelogram mechanism, such double parallelogram RCM mechanism principle is simple, but to realize or have usability need to overcome some application difficulties, such as how to realize the balance between two degrees of freedom related joints, damping and locking functions. SUMMARY

[0005] In view of the above problems, one of the purposes of the present application is to provide a double parallelogram RCM mechanism, which has the characteristics of convenience, easy to use and safety; another purpose of the present application is to provide a minimally invasive surgical robot with the double parallelogram RCM mechanism.

[0006] To achieve the above object, the present application adopts the following technical scheme: a double parallelogram RCM mechanism, comprising a follow-stop rotary joint and a double parallelogram linkage; the follow-stop rotary joint is associated with an input end of the double parallelogram linkage; an output end of the double parallelogram linkage is associated with an external surgical execution mechanism, so that an axis of the surgical execution mechanism always passes through an RCM point of the double parallelogram linkage; a first locking mechanism is arranged between the follow-stop rotary joint and the input end of the double parallelogram linkage, for locking or unlocking a rotary pair between the follow-stop rotary joint and the double parallelogram linkage; a second locking mechanism is arranged on at least one hinged joint of the double parallelogram linkage, for locking or unlocking a rotary pair between two linkages forming the hinged joint.

[0007] Preferably, the follow-stop rotary joint of the double parallelogram RCM mechanism comprises a spring assisting mechanism, which comprises: a mounting portion; a rotating connection portion fixedly connected or integrally formed with the input end of the double parallelogram linkage, and a rotating axis of the rotating connection portion is parallel to a length direction of the mounting portion and the input end of the double parallelogram linkage; a limiting portion arranged in the mounting portion; an elastic portion limited in the mounting portion by the limiting portion; a blocking portion arranged on the rotating connection portion; when an external force drives the double parallelogram linkage to rotate relative to the follow-stop rotary joint, the blocking portion compresses the elastic portion with the rotation of the rotating connection portion, and the elastic portion generates a counterforce equivalent to the external force to achieve force balance.

[0008] Preferably, the rotating connection portion is rotatably mounted in the mounting portion by a bearing, the elastic portion is a torsion spring, the torsion spring is sleeved outside the rotating connection portion, and at least one end of the torsion spring can contact the blocking portion, and the blocking portion is used for positioning and compressing the torsion spring.

[0009] Preferably, the limiting portion comprises a limiting baffle arranged in the mounting portion, the limiting baffle forms a limiting slot for limiting movement of the torsion spring within a given angle range, one end of the torsion spring is movably limited in the limiting slot of the limiting baffle, and the other end of the torsion spring is fixed on the mounting portion.

[0010] Preferably, the blocking portion is a stop nail formed on the rotating connection portion close to the limiting baffle.

[0011] The double parallelogram RCM mechanism, preferably, the limiting part comprises two limiting baffle plates which are arranged in the installation part at intervals, and the two limiting baffle plates are formed with limiting grooves for limiting the movement of the torsion spring within a given angle range, and the two ends of the torsion spring are respectively movably limited in the limiting grooves of the two limiting baffle plates.

[0012] The double parallelogram RCM mechanism, preferably, the blocking part is two blocking nails which are respectively formed on the rotating connecting parts close to the two limiting baffle plates.

[0013] The double parallelogram RCM mechanism, preferably, the follow-stop rotary joint further comprises a damping increasing mechanism, and the damping increasing mechanism comprises: a guide piece which is arranged on the installation part and can be screwed in or out along the radial direction of the installation part; a friction piece which is arranged outside the rotating connecting part and is movable in the radial direction and non-rotatable in the circumferential direction, and a friction interface exists between the friction piece and the rotating connecting part, and a gap exists between the friction piece and the guide piece; and an elastic piece which is arranged between the guide piece and the friction piece.

[0014] The double parallelogram RCM mechanism, preferably, a mounting through hole for mounting the guide piece and the friction piece is formed in the installation part, a part of the mounting through hole is formed into a threaded hole, at least a part of the guide piece is formed into an external thread section which is matched with the threaded hole, and the external thread section of the guide piece is screwed into the threaded hole of the mounting through hole; another part of the mounting through hole is formed into a guide hole, and at least a part of the friction piece is slidingly matched in the guide hole of the mounting through hole, so as to limit the circumferential movement of the friction piece but not limit the radial movement of the friction piece along the rotating shaft.

[0015] The double parallelogram RCM mechanism, preferably, the first locking mechanism is an end face tooth engagement locking mechanism, the end face tooth engagement locking mechanism comprises: an end face tooth shaped disc fixed on the mounting portion; an end face tooth translation block slidably arranged on the input end of the double parallelogram linkage, and the side of the end face tooth translation block close to the end face tooth shaped disc has meshing teeth matched with the end face tooth shaped disc, the end face tooth translation block is movable along the length direction of the double parallelogram linkage, so as to be engaged with or disengaged from the end face tooth shaped disc; a retaining plate fixed on the input end of the double parallelogram linkage, and the retaining plate is located on the side of the end face tooth translation block away from the end face tooth shaped disc; a guide screw connected with the end face tooth translation block and the retaining plate; a compression spring sleeved on the guide screw, and one end of the compression spring abuts against the retaining plate, and the other end of the compression spring abuts against the end face tooth translation block; an unlocking control line, one end of the unlocking control line is connected with the end face tooth translation block, and the other end of the unlocking control line is connected with an unlocking handle of the surgical execution mechanism.

[0016] The double parallelogram RCM mechanism, preferably, the second locking mechanism is a peripheral surface tooth engagement locking mechanism, the peripheral surface tooth engagement locking mechanism comprises: a peripheral surface tooth shaped disc fixed on a first link forming a certain hinged joint of the double parallelogram linkage; a peripheral surface tooth translation block slidably arranged on a second link forming the hinged joint, and the hinged axis of the hinged joint is perpendicular to the length directions of the first link and the second link; the peripheral surface tooth translation block has meshing teeth matched with the peripheral surface tooth shaped disc on the side close to the peripheral surface tooth shaped disc, and the peripheral surface tooth translation block is movable along the length direction of the second link, so as to be engaged with or disengaged from the peripheral surface tooth shaped disc; a retaining plate fixed on the second link, and the retaining plate is located on the side of the peripheral surface tooth translation block away from the peripheral surface tooth shaped disc; a guide screw connected with the peripheral surface tooth translation block and the retaining plate; a compression spring sleeved on the guide screw, and one end of the compression spring abuts against the retaining plate, and the other end of the compression spring abuts against the peripheral surface tooth translation block; an unlocking control line, one end of the unlocking control line is connected with the peripheral surface tooth translation block, and the other end of the unlocking control line is connected with an unlocking handle of the surgical execution mechanism.

[0017] The double parallelogram RCM mechanism, preferably, further comprises a damping adjusting mechanism on the rest of the at least one hinged joint of the double parallelogram linkage, the damping adjusting mechanism comprising: a rotating part having an inner ring and an outer ring which are rotatable relative to each other, and the outer ring of the rotating part being fixedly connected with a third link forming the hinged joint; a first friction part connected with the inner ring of the rotating part and a fourth link forming the hinged joint; a second friction part axially movable and circumferentially non-rotatable arranged on the third link, and a friction interface being formed between the second friction part and the first friction part; and an adjusting part connected with the second friction part for driving the second friction part to move towards or away from the first friction part so as to increase or decrease the frictional damping of the contact interface between the second friction part and the first friction part.

[0018] The double parallelogram RCM mechanism, preferably, the adjusting part comprises: a retainer fixedly connected with the third link and the outer ring of the rotating part, and a gap being left between the retainer and the rotating part, the first friction part and the second friction part being located in the gap between the retainer and the rotating part; a guide arranged in the retainer and rotatable along the axis of the damping adjusting mechanism; and an elastic member, one end of the elastic member abutting against the guide, and the other end of the elastic member abutting against the first friction part.

[0019] The double parallelogram RCM mechanism, preferably, the guide comprises a guide rod and a screw head integrally formed at one end of the guide rod, the outer periphery of the screw head having external threads, the inner ring of the retainer having internal threads matched with the external threads of the screw head, and the screw head being threadedly connected in the retainer; an elastic member positioning sleeve being formed between the guide rod and the screw head, the elastic member being sleeved on the guide rod, one end of the elastic member being located in the elastic member positioning sleeve, and the other end of the elastic member abutting against the first friction part.

[0020] The double parallelogram RCM mechanism preferably comprises: a first connecting rod, one end of the first connecting rod forming an input end of the double parallelogram linkage, and the length direction of the first connecting rod being parallel to the rotation axis of the follow-stop rotation mechanism; a second connecting rod and a third connecting rod, the second connecting rod and the third connecting rod being arranged in parallel and spaced apart, and the connecting parts of the second connecting rod and the third connecting rod with the first connecting rod each forming a hinged joint; a fourth connecting rod and a fifth connecting rod, arranged in parallel and spaced apart with the first connecting rod, and the connecting parts of the fourth connecting rod and the fifth connecting rod with the second connecting rod and the third connecting rod each forming a hinged joint; and a sixth connecting rod, arranged in parallel and spaced apart with the second connecting rod and the third connecting rod, and the connecting parts of the sixth connecting rod with the fourth connecting rod and the fifth connecting rod each forming a hinged joint, the sixth connecting rod being used to carry the surgical execution mechanism, so that the axis of the surgical execution mechanism always passes through the RCM point of the double parallelogram linkage.

[0021] The double parallelogram RCM mechanism preferably further comprises two limit screws arranged on the first connecting rod of the double parallelogram linkage, for limiting the torsion angle of the double parallelogram linkage within a certain range.

[0022] The double parallelogram RCM mechanism preferably further comprises a gravity balance mechanism arranged on the double parallelogram linkage, the gravity balance mechanism comprising at least one tension spring, the tension spring connecting two different connecting rods of at least one parallelogram in the double parallelogram linkage, and when only a normal load acts, the movement direction of the parallelogram is such that the distance between the tension spring and the two connecting points of the parallelogram increases.

[0023] The double parallelogram RCM mechanism preferably further comprises an encoder arranged on at least one hinged joint of the follow-stop rotation joint and / or the double parallelogram linkage, for calculating the precise value of the rotation angle of the follow-stop rotation joint and / or the hinged joint of the double parallelogram linkage.

[0024] A minimally invasive surgical robot comprising the double parallelogram RCM mechanism and a surgical execution mechanism, the surgical execution mechanism comprising a linear module, an unlocking handle and a surgical tool, the linear module being arranged on the output end of the double parallelogram linkage, and the surgical tool being able to translate along the linear module, so as to approach or move away from a surgical incision through the RCM point of the double parallelogram linkage.

[0025] The application has the following advantages: 1. The RCM mechanism based on double parallelogram linkage is adopted, and the RCM mechanism has greater rigidity and can be used in occasions with greater load. 2. The power assisting mechanism is additionally arranged on the RCM mechanism, so that the force used by the operator during operation can be reduced, thereby facilitating the operator to perform surgical operation. 3. The damping mechanism is additionally arranged on the RCM mechanism, so that the two degrees of freedom of the RCM mechanism can achieve the random stop function, the operator is more easily adjusted to the abdominal point, and the joint free movement is avoided, thereby increasing the safety of the operation. 4. The locking mechanism is additionally arranged on the RCM mechanism, so that the two degrees of freedom of the RCM mechanism can be in the completely locked state, thereby further increasing the safety of the operation. Compared with the traditional RCM mechanism, the application has stronger practicability, operability and safety. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a front view of a minimally invasive surgical robot according to an embodiment of the application;

[0027] Figure 2 is a rear view of the minimally invasive surgical robot according to the embodiment of the application;

[0028] Figure 3 is a schematic view of an end face structure of a random stop rotary joint according to the embodiment of the application;

[0029] Figure 4 is a schematic view of an internal structure of the random stop rotary joint according to the embodiment of the application;

[0030] Figure 5 is a schematic view of a mounting shell structure according to the embodiment of the application;

[0031] Figure 6 is a schematic view of a damping increasing mechanism according to the embodiment of the application;

[0032] Figure 7 is a sectional view of the damping increasing mechanism according to the embodiment of the application;

[0033] Figure 8 is a schematic view of a first locking mechanism according to the embodiment of the application;

[0034] Figure 9 is a schematic view of a second locking mechanism according to the embodiment of the application;

[0035] Figure 10 is a sectional view of a damping adjusting mechanism according to the embodiment of the application;

[0036] Figure 11 is a schematic view of an adjustable damping mechanism according to the embodiment of the application;

[0037] Figure 12is an exploded view of the adjustable damping mechanism of the embodiment of the present application;

[0038] Figure 13 is a structural schematic view of the guide screw of the embodiment of the present application. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present application will be described in detail with reference to the drawings, so that the objects, features and advantages of the present application can be more clearly understood. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present application, but only to illustrate the essential spirit of the technical solutions of the present application.

[0040] As shown in Figure 1 , Figure 2 The double-parallelogram RCM mechanism provided by the embodiment includes a follow-stop rotary joint 1 and a double-parallelogram linkage 2. The follow-stop rotary joint 1 is associated with the input end of the double-parallelogram linkage 2, and the double-parallelogram linkage 2 rotates about the rotation axis I of the follow-stop rotary joint 1. The output end of the double-parallelogram linkage 2 is associated with an external surgical execution mechanism 3, and the double-parallelogram linkage 2 has a rotational degree of freedom about the hinged axis II. Regardless of the rotation angle about the rotation axis I and / or the hinged axis II, the double-parallelogram linkage 2 can ensure that the movement axis of the surgical execution mechanism 3 always passes through a fixed point P in space, and the fixed point P is the RCM point of the double-parallelogram linkage 2. A first locking mechanism 11 is arranged between the follow-stop rotary joint 1 and the input end of the double-parallelogram linkage 2, and is used to lock or unlock the rotary pair between the follow-stop rotary joint 1 and the double-parallelogram linkage 2. A second locking mechanism 21 is arranged on at least one hinged joint of the double-parallelogram linkage 2, and is used to lock or unlock the rotary pair between the two linkages forming the hinged joint.

[0041] In the above embodiment, preferably, as Figures 3 to 5As shown, the follow-stop rotary joint 1 comprises a spring assisting mechanism 12 and a damping increasing mechanism 13. The spring assisting mechanism 12 comprises a mounting shell 12-1, a rotating shaft 12-2, a bearing 12-3, a torsion spring 12-4, a stop pin 12-5, a stop pin 12-6 and a limiting baffle 12-7. The inner ring of the bearing 12-3 is in contact with the rotating shaft 12-2, and the outer ring of the bearing 12-3 is in contact with the mounting shell 12-1 (so that the bearing 12-3 is radially positioned by the contact between the inner and outer rings). The rotating shaft 12-2 is fixedly connected with (or integrally formed with) the input end of the double parallelogram linkage 2, so that the double parallelogram linkage 2 can rotate freely relative to the mounting shell 12-1, and the rotation axis I of the rotating shaft 12-2 is parallel to the length direction of the mounting shell 12-1 and the input end of the double parallelogram linkage 2. The stop pins 12-5 and 12-6 are formed at the two ends of the rotating shaft 12-2, and the torsion spring 12-4 is sleeved outside the rotating shaft 12-2, and the outer legs 4-A and 4-B on both sides of the torsion spring 12-4 are in contact with the stop pins 12-6 and 12-5, respectively. The limiting baffles 12-7 are arranged in the mounting shell 12-1 at the two ends of the rotating shaft 12-2, and limiting grooves 7-A and 7-B are formed on the limiting baffles 12-7 to limit the movement of the torsion spring 12-4 within a given angle range, and the outer legs 4-A and 4-B on both sides of the torsion spring 12-4 are movably limited in the limiting grooves 7-A and 7-B, respectively.

[0042] Therefore, when the double parallelogram linkage 2 rotates around the rotation axis I of the follow-stop rotary joint 1, the stop pins 12-5 and 12-6 fixedly connected with the rotating shaft 12-2 will also rotate, and the stop pins 12-5 / 12-6 will press the outer legs 4-B / 4-A corresponding thereto, so that the torsion spring 12-4 is compressed. At this time, the outer legs 4-A / 4-B on the other side of the torsion spring 12-4 are limited by the stop ends of the limiting grooves 7-A / 7-B and do not move. Therefore, the torsion spring 12-4 will also generate a balance force to balance the torque caused by the gravity of the double parallelogram linkage 2, so as to achieve the purpose of force balance and reduce the artificial force.

[0043] In the above embodiment, preferably, the limiting baffles 12-7 are annular plates, the limiting baffles 12-7 are sleeved outside the rotating shaft 12-2, and the limiting baffles 12-7 are integrally formed with or fixedly connected with the mounting shell 12-1. The limiting grooves 4-A and 4-B on the two limiting baffles 12-7 are both arc-shaped.

[0044] Of course, those skilled in the art can understand that in the above embodiment, only one limiting baffle 12-7 and one limiting stopper 12-5 can be provided, and only the outer leg 4-B of the torsion spring 12-4 can be movable and limited in the limiting slot 7-B of the limiting baffle 12-7, and the outer leg 4-A of the torsion spring 12-4 can be fixedly connected with the mounting shell 12-1, thereby forming a one-way assisted spring assisting mechanism 12.

[0045] In the above embodiment, preferably, as shown in Figure 6 Figure 7 The damping increasing mechanism 13 includes a guide screw 13-1 arranged on the mounting shell 12-1 and rotatable in or out of the radial direction of the mounting shell 12-1, a friction block 13-2 radially movable and circumferentially non-rotatable arranged outside the rotating shaft 12-2, and a friction interface existing between the friction block 13-2 and the rotating shaft 12-2, and a gap existing between the friction block 13-2 and the guide screw 13-1, and a compression spring 13-3 arranged between the guide screw 13-1 and the friction block 13-2. Thus, when the guide screw 13-1 is rotated in or out, the distance between the guide screw 13-1 and the friction block 13-2 can be changed, so as to change the compression amount of the compression spring 13-3 to change the pressure of the friction block 13-2 on the rotating shaft 12-2, and then control the size of the frictional damping received by the rotating shaft 12-2 when rotating.

[0046] In the above embodiment, preferably, a mounting through hole for mounting the guide screw 13-1 and the friction block 13-2 is arranged on the mounting shell 12-1, a part of the mounting through hole forms a threaded hole, a threaded part of the guide screw 13-1 has an external thread matched with the threaded hole, and the threaded part of the guide screw 13-1 is threadedly matched in the threaded hole of the mounting through hole; another part of the mounting through hole forms a guide hole, and at least a part of the friction block 13-2 is slidingly matched in the guide hole of the mounting through hole, so as to limit the circumferential movement of the friction block 13-2 but not limit the radial movement of the friction block 13-2 along the rotating shaft 12-2.

[0047] In the above embodiment, preferably, as shown in Figure 3 In order to realize the algorithm requirement in the operation process, an encoder 14 is further arranged on at least one hinged joint of the follow-stop rotating joint 1 and / or the double parallelogram linkage 2, so as to calculate the accurate value of the rotation angle of the hinged joint of the follow-stop rotating joint 1 and / or the double parallelogram linkage 2.

[0048] As shown in Figure 8 ​As shown, the first locking mechanism 11 adopts an end face tooth meshing locking mechanism, which comprises: an end face tooth disc 11-1 fixed on the mounting shell 12-1; an end face tooth translation block 11-2 slidably arranged on the input end of the double parallelogram linkage 2 through a sliding block 11-3 and a guide rail 11-4, and the side of the end face tooth translation block 11-2 close to the end face tooth disc 11-1 is provided with meshing teeth matched with the end face tooth disc 11-1, and the end face tooth translation block 11-2 is movable along the length direction of the double parallelogram linkage 2, so as to be engaged or disengaged with the end face tooth disc 11-1.

[0049] Meanwhile, a retaining plate 11-6 is fixedly arranged on the input end of the double parallelogram linkage 2 on the other side of the end face tooth translation block 11-2 away from the end face tooth disc 11-1, and two guide screws 11-7 are symmetrically arranged on the retaining plate 11-6 along the length direction of the linkage 2, and the two guide screws 11-7 are threadedly connected with the end face tooth translation block 11-2 and the retaining plate 11-6. A compression spring 11-8 is sleeved on the two guide screws 11-7, one end of the compression spring 11-8 abuts against the end face tooth translation block 11-2, and the other end of the compression spring 48 abuts against the retaining plate 11-6. An unlocking control line 11-5 is arranged on the retaining plate 11-6 between the two guide screws 11-7, and the unlocking control line 11-5 mainly comprises an outer sleeve 5-1 and an inner coil wire 5-2, one end of the outer sleeve 5-1 is connected to the retaining plate 11-6, one end of the inner coil wire 5-2 passes through the outer sleeve 5-1 and is fixedly connected with the end face tooth translation block 11-2, and the other end of the inner coil wire 5-2 is connected with the unlocking handle 32 of the surgical execution mechanism 3.

[0050] Therefore, in the natural state, the several compression springs 11-8 will push the end face tooth translation block 11-2 to engage with the end face tooth disc 41, at this time the kinematic pair between the stop and rotate joint 1 and the double parallelogram linkage 2 is in the locked state, and the double parallelogram linkage 2 cannot be freely rotated; when the inner coil wire 5-2 of the unlocking control line 11-5 is pulled with sufficient force, the end face tooth translation block 11-2 will overcome the friction and the elastic force of the compression spring 11-8 to disengage with the end face tooth disc 11-1, at this time the kinematic pair between the stop and rotate joint 1 and the double parallelogram linkage 2 will be in the unlocked state, and the double parallelogram linkage 2 can be freely rotated.

[0051] As Figure 9As shown, the second locking mechanism 21 adopts a peripheral surface tooth meshing locking mechanism, which comprises: a peripheral surface toothed disc 21-1 fixed on a first link of a certain hinged joint of the double parallelogram linkage 2; a peripheral surface toothed translation block 21-2 slidably arranged on a second link of the hinged joint of the double parallelogram linkage 2 through a sliding block 21-3 and a guide rail 21-4, and the hinged axis of the hinged joint is perpendicular to the length direction of the first link and the second link at the same time; the peripheral surface toothed translation block 21-2 has meshing teeth matched with the peripheral surface toothed disc 21-1 on the side close to the peripheral surface toothed disc 21-1, and the peripheral surface toothed translation block 21-2 is movable along the length direction of the second link, so as to mesh or disengage with the peripheral surface toothed disc 21-1.

[0052] Meanwhile, a retaining plate 21-6 is fixedly arranged on the second link on the other side of the peripheral surface toothed translation block 21-2 away from the peripheral surface toothed disc 21-1, and two guide screws 21-7 are symmetrically arranged on the retaining plate 21-6 along the length direction of the second link, and the two guide screws 21-7 are threadedly connected with the peripheral surface toothed translation block 21-2 and the retaining plate 21-6 at the same time. A compression spring 21-8 is sleeved on the two guide screws 21-7, one end of the compression spring 21-8 abuts against the peripheral surface toothed translation block 21-2, and the other end of the compression spring 21-8 abuts against the retaining plate 21-6. An unlocking control line 21-5 is arranged on the retaining plate 21-6 between the two guide screws 21-7, and the unlocking control line 21-5 is mainly composed of an outer sleeve 5-1 and an inner coil wire rope 5-2, one end of the outer sleeve 5-1 is connected to the retaining plate 21-6, one end of the inner coil wire rope 5-2 is fixedly connected with the peripheral surface toothed translation block 21-2 after penetrating through the outer sleeve 5-1, and the other end of the inner coil wire rope 5-2 is connected with an unlocking handle 32 of the surgical execution mechanism 3.

[0053] Therefore, in the natural state, the several compression springs 21-8 will push the peripheral surface toothed translation block 21-2 to mesh with the peripheral surface toothed disc 21-1, at this time, the kinematic pair between the first link and the second link is in the locked state, and the first link and the second link cannot rotate freely; when the inner coil wire rope 5-2 of the unlocking control line 21-5 is pulled with sufficient force, the peripheral surface toothed translation block 21-2 will overcome the friction and the elastic force of the compression spring 21-8 to disengage with the peripheral surface toothed disc 21-1, at this time, the kinematic pair between the first link and the second link will be in the unlocked state, and the first link and the second link can rotate freely.

[0054] In the above embodiment, preferably, as shown in Figure 1 A damping adjustment mechanism 23 is also arranged on at least one of the remaining hinged joints of the double parallelogram linkage 2. As shown in Figures 10 to 12As shown, the adjustable damping mechanism 23 comprises a cross roller bearing 23-1, an outer ring of the cross roller bearing 23-1 is fixedly connected with the third bar 2-A forming the hinged joint, an inner ring friction ring 23-2 (which can also be a friction block or a friction sheet) is fixedly connected with the inner ring of the cross roller bearing 23-1 and the fourth bar 2-B forming the hinged joint through a bolt 23-7 and a nut 23-8, an outer ring friction ring 23-3 is axially movable and circumferentially non-rotatable arranged on the third bar 2-A, and a contact interface is formed between the outer ring friction ring 23-3 and the inner ring friction ring 23-2, an adjusting part connected with the outer ring friction ring 23-3 is used to drive the outer ring friction ring 23-3 to move towards or away from the inner ring friction ring 23-2 along the axis of the damping adjusting mechanism 23, so as to increase or decrease the frictional damping of the contact interface between the outer ring friction ring 23-3 and the inner ring friction ring 23-2.

[0055] In the above embodiment, preferably, as Figure 12 、 Figure 13As shown, the adjusting part includes a retainer 23-4, a compression spring 23-5 and a guide screw 23-6. The retainer 23-4 is fixedly connected with the third bar 2-A and the outer ring of the cross roller bearing 23-1 through a bolt 23-9 and a nut 23-10, and a gap is left between the retainer 23-4 and the cross roller bearing 23-1, and the inner ring friction ring 23-2 and the outer ring friction ring 23-2 are located in the gap between the retainer 23-4 and the cross roller bearing 23-1; the guide screw 23-6 mainly consists of a guide rod 6-1 and a screw head 6-2 integrally formed at one end of the guide rod 6-1, and the outer periphery of the screw head 6-2 has external threads, and at the same time, the inner ring of the retainer 23-4 has internal threads matched with the external threads of the screw head 6-2, and the screw head 6-2 is threadedly connected in the retainer 23-4; a spring positioning sleeve 6-3 is formed between the guide rod 6-1 and the screw head 6-2, the compression spring 23-5 is sleeved on the guide rod 6-1, one end of the compression spring 23-5 is located in the spring positioning sleeve 6-3, and the other end of the compression spring 23-5 abuts against the inner ring friction ring 23-2. Thus, when the guide screw 23-6 is rotated to move inward along the axis of the damping adjusting mechanism 23 (i.e. to screw in), the compression amount of the compression spring 23-5 will be increased, so that greater frictional damping is generated between the outer ring friction ring 23-3 and the inner ring friction ring 23-2, to limit the relative rotation between the inner and outer rings of the cross roller bearing 23-1, and further limit the relative rotation of the third bar 2-A and the fourth bar 2-B connected with the inner and outer rings of the cross roller bearing 23-1 respectively; on the contrary, when the guide screw 23-6 is rotated to move outward along the axis of the damping adjusting mechanism 23 (i.e. to screw out), the compression amount of the compression spring 23-5 will be reduced, so that the frictional damping between the outer ring friction ring 23-3 and the inner ring friction ring 23-2 is reduced, to facilitate the relative rotation between the inner and outer rings of the cross roller bearing 23-1, and further facilitate the relative rotation of the third bar 2-A and the fourth bar 2-B connected with the inner and outer rings of the cross roller bearing 23-1 respectively.

[0056] In the above embodiments, preferably, as Figure 1As shown, the double parallelogram linkage 2 comprises: a first connecting rod 2-1, one end of the first connecting rod 2-1 is fixedly connected with the rotating shaft 12-2 (may also be integrally formed with the rotating shaft 12-2), and the length direction of the first connecting rod 2-1 is parallel to the rotating axis I of the stop-and-go rotating mechanism 1; a second connecting rod 2-2 and a third connecting rod 2-3, the second connecting rod 2-2 and the third connecting rod 2-3 are arranged in parallel and spaced, and the connecting parts of the second connecting rod 2-2 and the third connecting rod 2-3 with the first connecting rod 2-1 are formed as hinged joints; a fourth connecting rod 2-4 and a fifth connecting rod 2-5, which are arranged in parallel and spaced with the first connecting rod 2-1, and the connecting parts of the fourth connecting rod 2-4 and the fifth connecting rod 2-5 with the second connecting rod 2-2 and the third connecting rod 2-3 are formed as hinged joints; and a sixth connecting rod 2-6, which is arranged in parallel and spaced with the second connecting rod 2-2 and the third connecting rod 2-3, and the connecting parts of the sixth connecting rod 2-6 with the fourth connecting rod 2-4 and the fifth connecting rod 2-5 are formed as hinged joints, the sixth connecting rod 2-6 is used to carry the surgical execution mechanism 3, so that the axis of the surgical execution mechanism 3 always passes through the fixed point P.

[0057] In the above embodiment, preferably, a gravity balance mechanism 22 is further arranged on the double parallelogram linkage 2, the gravity balance mechanism 22 comprises at least one tension spring, the tension spring connects two different connecting rods of at least one parallelogram in the double parallelogram linkage 2, and when only a normal load acts, the movement direction of the parallelogram is such that the distance between the tension spring and the two connecting points of the parallelogram increases, so that the balance force provided by the tension spring can balance most of the gravity of the connecting rod and the load.

[0058] In the above embodiment, preferably, limit screws 25 and 26 are further arranged on the first connecting rod 2-1 of the double parallelogram linkage 2, for limiting the torsion angle of the double parallelogram linkage 2 within a certain range.

[0059] Based on the double parallelogram RCM mechanism provided in the above embodiment, the present application further provides a minimally invasive surgery robot, which comprises a stop-and-go rotating joint 1, a double parallelogram linkage 2 and a surgical execution mechanism 3, the surgical execution mechanism 3 comprises a linear module 31, an unlocking handle 32 and a surgical tool 33, the linear module 31 is arranged on the output end of the double parallelogram linkage 2, and the surgical tool 33 can be translated along the linear module 31 to approach or move away from a surgical incision through the fixed point P.

[0060] The above embodiments are only used for describing the present application, and the structure, connection mode and manufacturing process of each component can be changed, and any equivalent transformation and improvement based on the technical scheme of the present application shall not be excluded from the protection scope of the present application.

Claims

1. A double parallelogram RCM mechanism characterized by, The device comprises a follow-stop rotary joint and a double parallelogram linkage; the follow-stop rotary joint is associated with the input end of the double parallelogram linkage; the output end of the double parallelogram linkage is associated with an external surgical execution mechanism, so that the axis of the surgical execution mechanism always passes through the RCM point of the double parallelogram linkage; a first locking mechanism is arranged between the follow-stop rotary joint and the input end of the double parallelogram linkage, for locking or unlocking the rotary pair between the follow-stop rotary joint and the double parallelogram linkage; a second locking mechanism is arranged on at least one hinged joint of the double parallelogram linkage, for locking or unlocking the rotary pair between the two linkages forming the hinged joint; The follow-stop rotary joint comprises a spring-assisted mechanism, which comprises: a mounting portion; a rotary connecting portion fixedly connected with or integrally formed with the input end of the double parallelogram linkage, and the rotary axis of the rotary connecting portion is parallel to the length direction of the mounting portion and the input end of the double parallelogram linkage; a limiting portion arranged in the mounting portion; an elastic portion limited in the mounting portion by the limiting portion; a blocking portion arranged on the rotary connecting portion; When an external force drives the double parallelogram linkage to rotate relative to the follow-stop rotary joint, the blocking portion rotates with the rotary connecting portion; The rotary connecting portion is rotatably mounted in the mounting portion by a bearing, the elastic portion is a torsion spring, the torsion spring is sleeved outside the rotary connecting portion, and at least one end of the torsion spring can contact the blocking portion, and the blocking portion is used for positioning and compressing the torsion spring; The limiting portion comprises two limiting baffles arranged in the mounting portion, the two limiting baffles are provided with limiting grooves for limiting the movement of the torsion spring within a given angle range, and the two ends of the torsion spring are respectively movably limited in the limiting grooves of the two limiting baffles; the limiting baffles are integrally formed with or fixedly connected with the mounting portion; The blocking portion is two stop nails respectively formed on the rotary connecting portion close to the two limiting baffles; When an external force drives the double parallelogram linkage to rotate relative to the follow-stop rotary joint, one end of the torsion spring moves along the corresponding limiting groove under the pressing of the corresponding stop nail, and the other end of the torsion spring is limited by the corresponding limiting groove.

2. The dual-parallelogram RCM mechanism of claim 1, wherein, The follow-stop rotary joint further comprises a damping increasing mechanism, which comprises: a guide piece arranged on the mounting portion and rotatable in or out of the radial direction of the mounting portion; a friction piece movably arranged outside the rotary connecting portion in the radial direction and not rotatable in the circumferential direction, and a friction interface exists between the friction piece and the rotary connecting portion, and a gap exists between the friction piece and the guide piece; an elastic piece arranged between the guide piece and the friction piece.

3. The dual-parallelogram RCM mechanism of claim 2, wherein, The mounting portion is provided with a mounting through hole for mounting the guide and the friction element, a part of the mounting through hole forms a threaded hole, at least a part of the guide forms an external thread section matched with the threaded hole, and the external thread section of the guide is threadedly matched in the threaded hole of the mounting through hole; another part of the mounting through hole forms a guide hole, and at least a part of the friction element is slidingly matched in the guide hole of the mounting through hole, so as to limit the circumferential movement of the friction element but not limit the radial movement of the friction element along the rotating connection portion.

4. The dual-parallelogram RCM mechanism of claim 1, wherein, The first locking mechanism is a face tooth meshing locking mechanism, which comprises: a face tooth disc fixed on the mounting portion; a face tooth translation block slidably arranged on the input end of the double parallelogram linkage, and the side of the face tooth translation block close to the face tooth disc is provided with meshing teeth matched with the face tooth disc, and the face tooth translation block is movable along the length direction of the double parallelogram linkage, so as to be meshed or disengaged with the face tooth disc; a retaining plate fixed on the input end of the double parallelogram linkage, and the retaining plate is located on the side of the face tooth translation block away from the face tooth disc; a guide screw connected with the face tooth translation block and the retaining plate; a compression spring sleeved on the guide screw, and one end of the compression spring abuts against the retaining plate, and the other end of the compression spring abuts against the face tooth translation block; an unlocking control line, one end of the unlocking control line is connected with the face tooth translation block, and the other end of the unlocking control line is connected with an unlocking handle of the surgical execution mechanism.

5. The dual-parallelogram RCM mechanism of claim 1, wherein, The second locking mechanism is a peripheral surface tooth meshing locking mechanism, which comprises: a peripheral surface tooth disc fixed on a first link forming a certain hinged joint of the double parallelogram linkage; a peripheral surface tooth translation block slidably arranged on a second link forming the hinged joint, and the hinged axis of the hinged joint is perpendicular to the length directions of the first link and the second link; the side of the peripheral surface tooth translation block close to the peripheral surface tooth disc is provided with meshing teeth matched with the peripheral surface tooth disc, and the peripheral surface tooth translation block is movable along the length direction of the second link, so as to be meshed or disengaged with the peripheral surface tooth disc; a retaining plate fixed on the second link, and the retaining plate is located on the side of the peripheral surface tooth translation block away from the peripheral surface tooth disc; a guide screw connected with the peripheral surface tooth translation block and the retaining plate; a compression spring sleeved on the guide screw, and one end of the compression spring abuts against the retaining plate, and the other end of the compression spring abuts against the peripheral surface tooth translation block; an unlocking control line, one end of the unlocking control line is connected with the peripheral surface tooth translation block, and the other end of the unlocking control line is connected with an unlocking handle of the surgical execution mechanism.

6. Double parallelogram RCM mechanism according to claim 4 or 5, characterized in that A damping adjustment mechanism is further arranged on at least one remaining hinged joint of the double parallelogram linkage, and the damping adjustment mechanism comprises: The rotating part has an inner ring and an outer ring which can rotate relative to each other, and the outer ring of the rotating part is fixedly connected with the third rod forming the articulated joint; The first friction part is connected with the inner ring of the rotating part and the fourth rod forming the articulated joint; The second friction part is axially movable and circumferentially non-rotatable on the third rod, and a friction interface is formed between the second friction part and the first friction part; The adjusting part is connected with the second friction part, and is used to drive the second friction part to move close to or away from the first friction part, so as to increase or decrease the frictional damping of the contact interface between the second friction part and the first friction part.

7. The dual-parallelogram RCM mechanism of claim 6, wherein, The adjusting part comprises: The retainer is fixedly connected with the third rod and the outer ring of the rotating part at the same time, and a gap is left between the retainer and the rotating part, and the first friction part and the second friction part are located in the gap between the retainer and the rotating part; The guide is arranged in the retainer and can be screwed in or out along the axis of the damping adjusting mechanism; The elastic member has one end abutting against the guide and the other end abutting against the first friction part.

8. The dual-parallelogram RCM mechanism of claim 7, wherein, The guide comprises a guide rod and a screw head integrally formed at one end of the guide rod, the outer periphery of the screw head has external threads, the inner ring of the retainer has internal threads matched with the external threads of the screw head, and the screw head is threadedly connected in the retainer; an elastic member positioning sleeve is formed between the guide rod and the screw head, the elastic member is sleeved on the guide rod, one end of the elastic member is located in the elastic member positioning sleeve, and the other end of the elastic member abuts against the first friction part.

9. The dual-parallelogram RCM mechanism according to any one of claims 1 to 5, 7, 8, wherein, The double-parallelogram linkage comprises: The first connecting rod has one end forming an input end of the double-parallelogram linkage, and the length direction of the first connecting rod is parallel to the rotation axis of the random-rotation joint; The second connecting rod and the third connecting rod are arranged in parallel and at intervals, and the connection positions of the second connecting rod and the third connecting rod with the first connecting rod all form articulated joints; The fourth connecting rod and the fifth connecting rod are arranged in parallel and at intervals with the first connecting rod, and the connection positions of the fourth connecting rod and the fifth connecting rod with the second connecting rod and the third connecting rod all form articulated joints; The sixth connecting rod is arranged in parallel and at intervals with the second connecting rod and the third connecting rod, and the connection positions of the sixth connecting rod with the fourth connecting rod and the fifth connecting rod all form articulated joints, and the sixth connecting rod is used to carry the surgical execution mechanism, so that the axis of the surgical execution mechanism always passes through the RCM point of the double-parallelogram linkage.

10. The dual-parallelogram RCM mechanism of claim 9, wherein, Two limiting screws are further arranged on the first connecting rod of the double-parallelogram linkage, and are used to limit the torsion angle of the double-parallelogram linkage within a certain range.

11. The dual-parallelogram RCM mechanism of claim 9, wherein, A gravity balance mechanism is further provided on the double parallelogram linkage, which includes at least one tension spring connecting two different links of at least one parallelogram in the double parallelogram linkage, and when only normal load is applied, the movement direction of the parallelogram is such that the distance between the tension spring and the two connection points of the parallelogram increases.

12. The dual-parallelogram RCM mechanism of claim 9, wherein, An encoder is further provided on the follow-stop rotary joint and / or at least one articulated joint of the double parallelogram linkage, to calculate the accurate value of the rotation angle of the follow-stop rotary joint and / or the articulated joint of the double parallelogram linkage.

13. A minimally invasive surgical robot, characterized by The double parallelogram RCM mechanism as claimed in any one of claims 1 to 12 is included, and a surgical execution mechanism is further included, which includes a linear module, an unlocking handle and a surgical tool, the linear module is arranged on the output end of the double parallelogram linkage, and the surgical tool can be translated along the linear module, so as to be close to or away from a surgical incision through the RCM point of the double parallelogram linkage.

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