Bearing arrangement of a swashplate in a steering gear component and surgical instrument

Abstract

Bearing arrangement (40) of a swashplate (14) in a steering gear component (33) of a surgical instrument (1), wherein the swashplate (14) is rotatably mounted about an axis of rotation (10) in a receiving opening (330) of the steering gear component (33), wherein the bearing arrangement (40) comprises a plurality of rolling elements (50) which are balls (50), characterized by the fact that the swashplate (14) has an outer circumferential surface (45) which provides a circumferential inner bearing surface (45.1), and The steering gear component (33) in the receiving opening (330) has an inner circumferential surface (332) which provides a circumferential outer bearing surface (333), and the plurality of rolling elements (50) are circumferentially distributed between the circumferential inner bearing surface (45.1) of the swashplate (14) and the circumferential outer bearing surface (333) of the steering gear component (33), such that the swashplate (14), the steering gear component (33) and the plurality of rolling elements (50) provide an integrated rolling bearing of the bearing arrangement (40), wherein the circumferential inner bearing surface (45.1) and the circumferential outer bearing surface (333) have a cross-section to form a four-point bearing, and a number of the rolling elements (50) is selected such that the majority of rolling elements (50) provide a full spherical bearing.

Description

[0001] The invention relates to a bearing arrangement of a swash plate in a steering gear component and to a surgical instrument having such a bearing arrangement.

[0002] Surgical instruments are known from the prior art that can be guided manually or by a robot, and that feature tools whose tool tips can be pivoted by means of several interlocking pivoting links. These pivoting links are connected to a multitude of steering wires or cables to achieve sensitive control of the tool tip. Using many thin steering wires compared to a few thicker ones allows for a more even distribution of force in all deflection directions.

[0003] From US 5,454,827 A it is known to couple such steering wires to a spatially adjustable disc arranged on the proximal side in an actuating unit, which is connected via a rod to a manually operable control lever, so that a movement of the spatially adjustable swash plate causes a corresponding relative movement of the distal-side pivoting members and thus a pivoting of the tool tip.

[0004] The design of the drive for the steering wires with the spatially adjustable swash plate on which the steering wires are mounted has the advantage that this enables a spatially compact design and only one component has to be moved in order to be able to address all the steering wires.

[0005] US 10,105,128 B2 discloses a surgical instrument with a mechanism to control the movement of a swash plate in two degrees of freedom via joint rods with proximal-side drives, but the swash plate is not rotatable in the instrument.

[0006] Furthermore, it is known to transmit drive angles to a swashplate for spatial alignment in two degrees of freedom / spatial directions in a surgical instrument with a steering gear component. The steering gear component is rotationally decoupled from the swashplate by a ball bearing. A cardanic mounting of the swashplate on a main shaft transmits a rotational movement of the instrument shaft to the swashplate, so that the spatial position of the swashplate is determined by a superposition of the movements of the steering gear component and the main shaft.

[0007] From DE 10 2019 121 092 A1, a bearing arrangement with a swash plate in a steering gear component of a surgical instrument is known, wherein the swash plate is mounted in a receiving opening of the steering gear component so as to be rotatable about an axis of rotation, and wherein the bearing arrangement has a plurality of rolling elements which are balls.

[0008] In the field of surgical instruments, in which bearing surfaces of rolling bearings are directly integrated into the components to be supported, the publications WO 2013 / 158 974 A1, US 2009 / 0 209 820 A1, US 2015 / 0 164 305 A1 and DE 20 2009 006 907 U1 are also known.

[0009] Based on this prior art, it is the object of the present invention to provide a mounting of a swash plate in a steering gear component which is improved with regard to the required installation space and which mounts a swash plate in a steering gear component in a rotationally decoupled manner.

[0010] This object is achieved by a bearing arrangement having the features of claim 1.

[0011] The further object of providing a surgical instrument having an improved mounting arrangement of the spatially adjustable swash plate is achieved by the surgical instrument having the features of independent claim 5.

[0012] Further developments and preferred embodiments of the storage arrangement and the surgical instrument are set out in the subclaims.

[0013] According to a first embodiment of the bearing arrangement according to the invention for a swash plate in a steering gear component, in which the swash plate is mounted in a receiving opening of the steering gear component so as to be rotatable about a rotational axis, the swash plate has an outer peripheral surface that provides a circumferential inner bearing surface. The steering gear component has an inner peripheral surface in the receiving opening that provides a circumferential outer bearing surface, which is arranged in the bearing arrangement axially corresponding to the circumferential inner bearing surface of the swash plate. Furthermore, the bearing arrangement has a plurality of rolling elements that are balls, wherein the rolling elements form a bearing with the circumferential inner bearing surface and the circumferential outer bearing surface, in that the rolling elements are received in a circumferentially distributed manner between the circumferential inner bearing surface and the circumferential outer bearing surface.The circumferential inner bearing surface and the circumferential outer bearing surface have a cross-section designed to form a four-point contact bearing, enabling them to also absorb axial forces. A number of rolling elements are selected to provide a full complement bearing. This creates a rolling bearing that is integrated into the unit consisting of the swashplate and steering gear component. Since the bearing arrangement does not require an inner and outer bearing ring, because the bearing running surfaces are integrated into the swashplate and steering gear component, less installation space is required and the bearing arrangement can be designed compactly. The swashplate itself thus provides the inner ring of the bearing, and the steering gear component provides the outer ring.

[0014] The “surfaces” here refer to surface sections of the swash plate and steering gear component, whereby the respective “surfaces” do not have to be flat and continuous, but can also be structured, i.e. uneven and discontinuous. The “outer peripheral surface” of the swash plate is to be understood as its outer surface between the end faces of the swash plate, whereby the “outer peripheral surface” or outer surface of the swash plate can be formed with different sections. At least one surface section of the “outer peripheral surface” is formed as the “circumferential inner bearing surface”, which forms an inner raceway of the integrated rolling bearing for the rolling elements. The same applies to the “inner peripheral surface” of the receiving opening of the steering gear component with the “circumferential outer bearing surface”: The “inner peripheral surface” is to be understood as the inner surface of the steering gear component between its front and rear sides, whereby the “inner peripheral surface” orThe inner circumferential surface of the steering gear component defines the receiving opening and can be formed with different sections. At least one surface section of the "inner circumferential surface" is formed as the "circumferential outer bearing surface," which forms an outer raceway of the integrated rolling bearing for the rolling elements. This means that both the "circumferential inner bearing surface" and the "circumferential outer bearing surface" can each consist of two surface sections, e.g., ball track sections, which can be connected to each other at a point or via a radius.

[0015] A four-point bearing design may be preferred, as it can particularly effectively absorb axial forces in both directions that occur during operation. In particular, tilting moments, which are a central load case of a swashplate, can be optimally absorbed and transmitted by a four-point bearing.

[0016] Full complement ball bearings are preferred because they can carry higher loads than designs with cages or separators, and they require less space than designs with bearing cages and are less difficult to assemble than designs with separators.

[0017] In a further preferred embodiment of the bearing arrangement according to the invention, a filling device for filling the bearing raceway provided between the circumferential inner bearing surface and the circumferential outer bearing surface is provided in that the steering gear component has an access bore that extends to the circumferential outer bearing surface and that can be closed with a filling plug. Naturally, the access bore has a cross-section adapted to the dimensions of the rolling element to enable filling. A filling plug is understood here to be any closure means suitable for closing such an access bore in such a way that the rolling of the rolling elements filled into the bearing along the outer bearing surface is not impaired.

[0018] As an alternative to a filling device formed by a closable access hole, the swash plate or the steering gear component can be designed in two parts, with a parting plane dividing the circumferential inner bearing surface or the circumferential outer bearing surface. For this purpose, the swash plate can be separated axially at the inner bearing surface, and the steering gear component can be separated radially or axially at the outer bearing surface. Filling with the rolling elements takes place in an assembly arrangement of the swash plate and steering gear component, with only a first component of the two-part component being mounted, and the assembly of the second component to form the bearing arrangement only taking place after filling has been completed.

[0019] Another alternative embodiment for filling the bearing with the rolling elements can provide for the swash plate and the steering gear component to be displaceable relative to each other in the direction of the rotation axis, so that axial displacement creates a gap in the bearing area through which the rolling elements can be filled. Since a flank or a surface section of one of the raceways, the outer bearing surface or the inner bearing surface, is shaped differently for this purpose, this embodiment is only suitable for absorbing bearing forces to a limited extent. Furthermore, in this embodiment, the provision of a securing device is useful, ensuring that the assembly gap always remains closed during operation.

[0020] Among the filling variants, the design with a closable access hole is preferred, since this avoids design disadvantages that can arise from a two-part design of the swash plate or the steering gear component or from unfavorable rolling element guidance in the case of a movable swash plate and steering gear component.

[0021] In a further embodiment, the swash plate of the bearing arrangement according to the invention is arranged on a shaft that defines the axis of rotation. For this purpose, the shaft has a spherical portion where the shaft diameter is widened to form the spherical contour, and the swash plate has a receiving recess on its inner side that is contoured at least partially to the spherical portion, so that the swash plate is mounted on the shaft so that it can move about two axes perpendicular to the axis of rotation without axial offset. In order to transmit a rotation or an angle of rotation of the shaft to the swash plate, the spherical portion of the shaft has two guide grooves in its outer surface that extend diametrically and in the longitudinal direction of the shaft and engage two pins that are arranged diametrically and point radially inwards on the swash plate or an inner side of the swash plate.

[0022] This advantageously results in a torsionally rigid connection between the shaft and the swash plate, which allows rotational angle transmission even with a large angular offset (± 40° and more), but is still very compact and easy to manufacture and assemble.

[0023] According to yet another embodiment of the bearing arrangement, the receiving recess in the swash plate can be spherically shaped, corresponding to the spherical portion, whereby the receiving recess acts on both sides in the manner of a joint socket, thus completely securing the coupling axially. A two-part design of the swash plate enables assembly by mounting the swash plate parts onto the spherical portion to complete the swash plate.

[0024] According to an alternative embodiment, the receiving recess in the swash plate has a spherical section and a cylindrical or widening section, so that the swash plate is fixed only on one side by the spherical section and mounting on the spherical section is made possible by the cylindrical or widening section pointing in the direction of the spherical section when pushed onto the shaft.

[0025] The surgical instrument according to the invention, which has a bearing arrangement for a swash plate in a steering gear component, provides in a first embodiment that the bearing arrangement is a bearing arrangement according to the invention, since the bearing arrangement according to the invention, due to its compact design, is particularly suitable for installation in a surgical instrument having a main shaft and a hollow shaft running coaxially to a longitudinal axis of the main shaft. An actuating unit is arranged at the proximal shaft end (i.e., the end closer to the actuator), and a tool tip with a tool is arranged at the distal end of the shaft. The tool tip can be actuated via an actuating element mounted axially displaceably in the shaft, which further extends through a longitudinally axial through-bore of the main shaft and is operatively connected to the actuating unit on the proximal side.The bearing arrangement according to the invention is designed for the spatial alignment of the swash plate with respect to the main shaft in cooperation with a proximal-side drive, so that a movement of the proximal-side drive causes the pivoting of the tool tip.

[0026] The bearing arrangement has an interface with the proximal-side drive via the steering gear component in order to transmit its setting angle to the swash plate for controlling the distal tool tip. The spatial alignment of the swash plate with respect to the main shaft by movement of the proximal-side drive causes the tool tip to pivot, which can be pivoted relative to the longitudinal axis of the shaft via a joint mechanism. In one embodiment, the joint mechanism can consist of pivoting members arranged at the distal end of the shaft, which are connected to the proximal-side drive via steering wires running in the longitudinal direction of the shaft. The steering wires are mounted on the swash plate, so that a movement of the proximal-side drive causes a corresponding relative movement of the distal-side pivoting members and thus the pivoting of the tool tip.

[0027] In a preferred embodiment of the bearing arrangement of the surgical instrument according to the invention, the proximal-side drive can be designed as a motorized drive with at least two drive wheels, e.g., driven gear wheels, between which the swash plate is arranged.

[0028] In this embodiment, the swash plate is coupled by the bearing arrangement to a third gear which is in engagement with the two drive wheels, wherein the steering gear component is a steering ring which is coupled in a rotationally fixed manner to the third gear, wherein a fourth gear is preferably arranged on the axis of rotation of the third gear offset by 180° to the third gear, which fourth gear is in engagement with the two driven gears, so that the toothed chain formed is closed to form a toothed ring which ensures a uniform circumferential force distribution.

[0029] Further embodiments, as well as some of the advantages associated with these and other embodiments, will become clearer and more easily understood from the following detailed description with reference to the accompanying figures. Items or parts thereof that are substantially the same or similar may be provided with the same reference numerals. The figures are merely a schematic representation of one embodiment of the invention.

[0030] Showing: Fig. 1 a schematic perspective side view of a surgical instrument, Fig. 2 a perspective detailed view of a swash plate bearing arrangement from the prior art with a ball bearing for supporting the swash plate in a steering ring of the drive for the surgical instrument, Fig. 3 a perspective view of a bearing arrangement according to an embodiment of the invention, Fig. 4 a side sectional view of the bearing arrangement of Fig. 3, Fig. 5 an exploded view of the side section view of Fig. 4 without rolling elements, Fig. 6 a detailed sectional view D of the bearing arrangement from Fig. 4, Fig. 7 a detailed sectional view through the bearing arrangement designed as a four-point bearing from Fig. 4, Fig. 8 a bottom view of the bearing arrangement Fig. 3, Fig. 9 is a perspective partial sectional view of the swash plate arranged on a spherical section of a main shaft, which is designed for mounting according to the invention in a steering ring of a drive for a surgical instrument, Fig. 10 is a partial sectional plan view of the swash plate arranged on the ball section of the main shaft from Fig. 8, and Fig. 11 is a perspective view of a swash plate for mounting in a steering ring of a drive for a surgical instrument and for arrangement on a spherical section of the main shaft.

[0031] Fig. 1 schematically shows a surgical instrument 1 with a hollow shaft 2, an actuating unit 4 arranged at the proximal end 3 of the shaft 2, shown only schematically, and a tool tip 6 arranged at the distal end 5 of the shaft 2 with a tool 7 that can be actuated via an actuating element 8 mounted axially displaceably in the shaft 2, which is operatively connected to the actuating unit 4 on the proximal side. The actuating unit 4 can be a manually actuated handle or a structural unit designed for robotic use, i.e., one that can also be actuated without manual intervention. The tool 7 of the tool tip 6 can, for example, be a tool provided with jaw parts, as in Fig. 1, or it could be an endoscope, an applicator or the like. The tool tip 6 can be pivoted relative to the longitudinal axis 10 of the shaft 2 via an articulated mechanism 9, wherein the articulated mechanism 9 consists of pivoting members 11 arranged at the distal end of the shaft 5, which are connected via steering wires 12 running in the longitudinal direction of the shaft 2 to a drive 13 arranged at the proximal end 3 of the shaft 2 in such a way that a movement of the proximal-side drive 13 causes a corresponding relative movement of the distal-side pivoting members 11 and thus a pivoting of the tool tip 6. Even if only the term steering wires 12 is used above and below, steering cables can also be used functionally, which is why the term steering wires 12 used should also be read and understood as a synonym for steering cable.

[0032] The actuating element 8, which is mounted axially displaceably in the shaft 2 and is used to actuate the tool 7, which consists, for example, of two jaw parts, is designed as a push / pull rod in the illustrated embodiments. The drive 13 for the steering wires 12 in the medical instrument 1 according to the invention can preferably be designed as a motorized drive 13, which has a spatially adjustable swash plate 14, on which the steering wires 12 are mounted such that a displacement of the swash plate 14, preferably effected via the motorized drive 13, via the steering wires 12, causes a pivoting of the tool tip 6, as is known from the prior art, e.g., US 10,105,128 B2 or the swash plate mounting arrangement from Fig. 2 known.

[0033] By using a motorized drive 13 for the spatially adjustable disc 14, it is possible to control the steering wires 12 for pivoting the distal pivoting elements 11 or the instrument tip 6 precisely, sensitively in the smallest steps, and also reproducibly. Furthermore, the number of steering wires 12 to be used for a motorized drive 13 is irrelevant. The motorized drive 13 can, as is known from the prior art according to Fig. 2, two drive units with gears 18 and 19, here bevel gears, driven by motors, between which the swash plate 14 is arranged.

[0034] In the surgical instrument 1 according to Fig. 1 (in conjunction with Fig. 2 - State of the art - or Fig. 3 to 11 - bearing arrangement 40 according to the invention), a hollow main shaft 21 extending coaxially to the longitudinal axis 10 of the shaft 2 is arranged in the shaft 2, which is rotatable about the longitudinal axis 10 of the shaft 2 and extends beyond the proximal end 3 of the shaft 2 into the area of ​​the motorized drive 13. The actuating element 8 for actuating the instrument 7 is mounted axially displaceably within this hollow main shaft 21.

[0035] The steering wires 12 emerging from the shaft 2 at the proximal end 3 of the shaft 2 are guided at the distal end of the main shaft 21 and can be fanned out via a fan-shaped washer (not shown) arranged on the main shaft 21 in a rotationally fixed manner, whereby the radial distance of the steering wires 12 from the longitudinal axis 10 of the shaft 2 is increased. The steering wires 12 running proximally behind such a fan-shaped washer parallel to the longitudinal axis 10 of the shaft 2 extend to the swash plate 14, to which the steering wires 12 are fixed. For this purpose, the swash plate 14 has an axially parallel through-bore 41 for each steering wire 12, wherein the steering wires 12 are fastened within the through-bores 41 via grub screws 41.2 as in Fig. 2 or proximal side with a clamping disc 41.1, as in Fig. 9 and Fig. 10, can be fixed and connected non-positively to the swash plate 14.

[0036] The driven gears 18 and 19 are coupled to a third gear 30, which meshes with the two driven gears 18 and 19 and whose rotational axis B intersects the central axis A of the driven gears 18 and 19 and the longitudinal axis 10 of the shaft 2. The third gear 30 is also preferably designed as a bevel gear. Through the three meshing gears 18, 19, and 30, every movement of the two driven gears 18 and 19 is transmitted directly to the swash plate 14 coupled to the third gear 30, which directly actuates the steering wires 12.In order to close the toothed chain formed by the gears 18, 19 and 30 into a closed toothed ring, which ensures a uniform circumferential force distribution, a fourth gear 31 is arranged on the rotational axis B of the third gear 30, offset by 180° from the third gear 30, which is in engagement with the two driven gears 18 and 19, wherein the fourth gear 31 is also preferably designed as a bevel gear.

[0037] The swash plate 14 is in the known bearing arrangement according to Fig. 2 is mounted via a (ball) bearing ring 32 in the steering ring 33, which is non-rotatably coupled to the third gear 30, in order to enable rotation of the swash plate 14 about the longitudinal axis 10 of the shaft 2. The steering ring 33, which is non-rotatably coupled to the third gear 30, is freely rotatable relative to the fourth gear 31 on a bearing support 331 via a bearing ring 34, so that rotation of the fourth gear 31 about its rotational axis B does not cause any rotation of the steering ring 33 and the swash plate 14. The use of a standard roller bearing, however, is only possible with the restriction of increased installation space requirements, which prevents the miniaturization of a surgical instrument equipped with it. Even a thin-ring bearing requires more installation space than is available between the steering ring and the swash plate for the desired miniaturization. A plain bearing meets the installation space requirements, but cannot absorb axial forces.

[0038] The above-mentioned with regard to Fig. 2 described embodiments of the drive 13 for the spatial alignment of the swash plate 14 for controlling the tool tip by means of the steering wires 12 also apply to a surgical instrument 1 according to the invention, which has a bearing arrangement 40 according to the invention, as shown in Fig. 3 to 10 can be seen.

[0039] The bearing arrangement 40 according to the invention, unlike the conventional ball bearing 32, does not have bearing rings that provide a raceway for rolling elements 50 to support the swash plate 14 rotatably about the rotation axis 10 in the receiving opening 330 of the steering ring 33. As in Fig. 4 to 6, the bearing raceways are integrated into the swash plate 14 and the steering ring 33 to save installation space. The swash plate 14 has a circumferential inner bearing surface 45.1 on its outer circumferential surface 45, thus assuming the function of a bearing inner ring, while the steering gear component 33 has a circumferential outer bearing surface 333 on the inner circumferential surface 332 of the receiving opening 330, which assumes the function of a bearing outer ring. The rolling elements 50, which are preferably balls so that the bearing can absorb not only radial but also axial loads, are received in a circumferentially distributed manner in the bearing raceway provided by the circumferential inner bearing surface 45.1 and the circumferential outer bearing surface 333.

[0040] With balls as rolling elements 50, the circumferential inner bearing surface 45.1 and the circumferential outer bearing surface 333 have a circular arc-shaped cross-section to form a deep groove ball bearing not according to the invention, the diameter of which is adapted to the diameter of the balls 50. However, the design as a four-point bearing is preferred, as in Fig. 7, so that axial loads can be absorbed in both directions, wherein the circumferential inner bearing surface 45.1 and the circumferential outer bearing surface 333 each have a cross-section of two intersecting circular arcs whose diameter is larger than the diameter of the balls 50, so that the balls only contact the inner bearing surface 45.1 and the outer bearing surface 333 at the four points shown.

[0041] In an embodiment not shown but not according to the invention, the bearing arrangement can have a bearing cage or separator for even spacing of the rolling elements, thereby preventing contact between adjacent rolling elements, thus reducing heat build-up due to friction and supporting even load distribution over the circumference. However, since such cages or separators can require more space, a full-complement design of the bearing arrangement 40 is preferred, which can also bear higher loads than a design with a cage. A full-complement bearing is created when the sum of the diameters D of all n rolling elements (n*D) approximately corresponds to the circumference U of their raceway, so that U-(n*D) < D, meaning there are no large gaps between two adjacent rolling elements.

[0042] In Fig. 8 shows an access hole 334 on the steering ring 33 closed by a filling plug 51 (in Fig. 3), which extends to the circumferential outer bearing surface 333 (not shown). The access bore 334 enables the filling of the bearing raceway formed between the inner bearing surface 45.1 of the swash plate 14 and the outer bearing surface 333 of the steering ring 33 with the rolling elements 50 before being closed with a filler plug 51. Replacement can be carried out accordingly by emptying old rolling elements through the access bore 334 after removing the filler plug 51 and filling in new rolling elements.

[0043] As an alternative to the preferred filling device by means of access bore 334, a bearing arrangement 40 according to the invention can be filled with rolling elements by the swash plate 14 or the steering gear component 33 being designed in two parts, wherein a parting plane divides the inner bearing surface 45.1 or the outer bearing surface 333, or by the swash plate 14 and the steering gear component 33 being designed on the outer peripheral surface 45 and the inner peripheral surface 332 such that they are displaceable relative to one another in the direction of the rotation axis 10, so that a gap is created in the region of the inner bearing surface 45.1 or the outer bearing surface 333, through which gap the bearing can be filled.

[0044] Fig. 9 to 11 illustrate the mounting of the swash plate 14 on the main shaft 21 of a surgical instrument 1 (cf. Fig. 1). The spatial orientation of the swash plate 14 for pivoting the tool tip 6 via the steering wires 12 is determined by a superposition of the rotational position of the main shaft 21 and the setting angle of the proximal-side drive (cf. Fig. 2). The bearing arrangement is structurally simple and compact, and easy to install.

[0045] The main shaft 21 has a ball section 24 for the ball-and-socket mounting of the swash plate 14, on which two guide grooves 22 are present, extending in the longitudinal direction of the shaft 21 and introduced on both sides or diametrically into the ball section 24. The swash plate 14 has a receiving recess 44 whose contours are at least partially adapted to the ball section 24, from which two diametrically and radially inwardly pointing pins 42 extend, which engage in the guide grooves 22 on the ball section 24 of the main shaft 21. For mounting the pins 42, the swash plate 14 can have two diametrically radially extending through-bores 43, such that the pins 42 can be inserted from the outer side 45 of the swash plate 14 through the through-bore 43 until they emerge on the inner side of the swash plate 14 and protrude radially inward to the desired length. The through holes 43 are axially from the circumferential inner bearing surface 45.1 on the outer peripheral surface 45, as shown in . Fig. 9. As an alternative to through-bores 43, in embodiments not shown, the pins 42 can be fastened to the swash plate 14 in two diametrically radially extending blind bores on the inside, or the pins 42 can be integrally connected to the swash plate 14 on the inside, e.g., manufactured in one piece.

[0046] The swash plate 14, which is ball-bearing mounted in this way, can rotate from a neutral position, in which the swash plate 14 lies in a plane perpendicular to the longitudinal or rotational axis 10, about two spatial axes (A, B, cf. Fig. 2). Furthermore, the engagement of the pins 42 in the guide grooves 22 allows a rotation angle of the shaft 21 to be transmitted to the swash plate 14.

[0047] The tilting or rotation of the swash plate 14 about one or both axes of rotation A, B relative to the longitudinal axis 10 of the shaft 2 causes, via the steering wires 12, the distal side of the instrument tip 6 to be pivoted accordingly relative to the longitudinal axis 10 of the shaft 2. By transmitting a rotational movement of the main shaft 21 about the longitudinal axis 10 of the shaft 2 to the swash plate 14, the tool tip 6, which is coupled to the distal side of the main shaft 21, can be rotated about the longitudinal axis 10 of the shaft 2.

[0048] In Fig.10 shows that the receiving recess 44 in the example shown consists of a proximal-side spherical section and a distal-side cylindrical section, which allows the mounting of the swash plate 14 by sliding it from the proximal end of the main shaft 21. As an alternative to a cylindrical section, a widening section (not shown) can be provided on the distal side. The swash plate 14 is fixed to the spherical section only on one side by the proximal-side spherical section, but is held by the tension of the steering wires 12, which here are passed through the through-openings 41 and fastened with a clamping ring 41.1 arranged on the proximal side, so that the swash plate 14 is fixed in the axial direction.In a modified embodiment, also not shown, the receiving recess 44 of the swash plate 14 can be formed with only a spherical section corresponding to the ball section 24 without a cylindrical or widened section, so that the ball-and-socket joint is completely axially fixed. However, this embodiment requires at least a two-part design of the swash plate 14 to enable mounting on the ball section 24. LIST OF REFERENCE SYMBOLS 1 Medical instrument 2 shaft 3, 5 Proximal, distal end (shaft) 4 Actuating unit 6, 7 tool tip, tool 8 Actuating element 9 Joint mechanism 10 Longitudinal axis 11 Swivel link 12 steering wire 13 Drive 14 Swashplate 18, 19 Gear (driven) 21 Main shaft 22 guide groove 23 Through hole 24 spherical section 27, 29 bearing pin 28 universal joint disc 30, 31 third, fourth gear 32, 34 bearing ring 33, 330, 331 steering ring, receiving opening, bearing support 332, 333 inner peripheral surface, outer bearing surface 334, 335 access hole, mounting foot 40 Storage arrangement 41, 41.1, 41.2 Through hole, fixing washer, grub screw 42 pin 43, 44 mounting hole, mounting recess 45, 45.1 Outer peripheral surface, inner bearing surface 50 rolling elements 51 Filling plug

Claims

[1] Bearing arrangement (40) of a swash plate (14) in a steering gear component (33) of a surgical instrument (1), wherein the swash plate (14) is mounted in a receiving opening (330) of the steering gear component (33) so as to be rotatable about a rotation axis (10), wherein the bearing arrangement (40) has a plurality of rolling elements (50) which are balls (50), characterized by , that the swash plate (14) has an outer peripheral surface (45) which provides a circumferential inner bearing surface (45.1), and the steering gear component (33) has an inner circumferential surface (332) in the receiving opening (330), which provides a circumferential outer bearing surface (333), and the plurality of rolling elements (50) are received in a circumferentially distributed manner between the circumferential inner bearing surface (45.1) of the swash plate (14) and the circumferential outer bearing surface (333) of the steering gear component (33), so that an integrated rolling bearing of the bearing arrangement (40) is provided by the swash plate (14), the steering gear component (33) and the plurality of rolling elements (50), wherein the circumferential inner bearing surface (45.1) and the circumferential outer bearing surface (333) have a cross-section to form a four-point bearing, and a number of the rolling elements (50) is selected such that the plurality of rolling elements (50) provides a full-ball bearing. [2] Bearing arrangement (40) according to claim 1, characterized by , that - the steering gear component (33) has an access bore (334) which extends to the peripheral outer bearing surface (333) and which can be closed with a filler plug (51), or - the swash plate (14) or the steering gear component (33) is designed in two parts, wherein a parting plane divides the circumferential inner bearing surface (45.1) or the circumferential outer bearing surface (333), or - the swash plate (14) and the steering gear component (33) are displaceable relative to one another in the direction of the rotation axis (10). [3] Bearing arrangement (40) according to claim 1 or 2, characterized by , that the swash plate (14) is arranged on a shaft (21) which defines the rotational axis (10), wherein the shaft (21) has a spherical section (24) for supporting the swash plate (14), and the swash plate (14) has a receiving recess (44) contoured at least partially to the spherical section (24), wherein - the ball section (24) has two diametrically arranged guide grooves (22) extending in the longitudinal direction of the shaft (21) and - two diametrically and radially inwardly pointing pins (42) are arranged on the swash plate (14), wherein each pin (42) engages in one of the guide grooves (22) so that an angle of rotation of the shaft (21) can be transmitted to the swash plate (14). [4] Bearing arrangement (40) according to claim 3, characterized by , that the receiving recess (44) is spherical in shape corresponding to the ball section (24), wherein the swash plate (14) is constructed in two parts, or the receiving recess (44) has a spherical portion (45) and a cylindrical or widening portion (46). [5] Surgical instrument (1) with a bearing arrangement of a swash plate (14) in a steering gear component (33), characterized bythat the bearing arrangement is a bearing arrangement (40) according to at least one of claims 1 to 4. [6] Surgical instrument (1) according to claim 5, characterized byin that the surgical instrument (1) is designed with a main shaft (21) running coaxially to a hollow shaft (2) and has an actuating unit (4) arranged at the proximal end (3) of the shaft (2) and a tool tip (6) arranged at the distal end (5) of the shaft (2) with a tool (7) which can be actuated via an actuating element (8) which is mounted axially displaceably in the shaft (2), which extends through a longitudinal axial through-bore (23) in the main shaft (21) and is operatively connected to the actuating unit (4) on the proximal side, wherein the tool tip (6) is pivotable relative to the longitudinal axis (10) of the shaft (2) via an articulated mechanism (9), and the articulated mechanism (9) is operatively connected to a proximal-side drive (13) which has the wobble plate (14). [7] Surgical instrument (1) according to claim 5 or 6, characterized bythat the joint mechanism (9) consists of pivoting members (11) arranged at the distal end (5) of the shaft (2), which are connected to the proximal-side drive (13) via steering wires (12) running in the longitudinal direction of the shaft (2) in such a way that a movement of the proximal-side drive (13) causes a corresponding relative movement of the distal-side pivoting members (11) and thus a pivoting of the tool tip (6), wherein the steering wires (12) are mounted on the swash plate (14). [8] Surgical instrument (1) according to at least one of claims 5 to 7, characterized by that the proximal-side drive (13) is designed as a motorized drive (13) with at least two drive wheels (18, 19) between which the swash plate (14) is arranged. [9] Surgical instrument (1) according to claim 8, characterized by , that the swash plate (14) is coupled by the bearing arrangement (40) to a third gear (30) which engages with the two drive wheels (18, 19), wherein the steering gear component (33) is a steering ring (33) which is non-rotatably coupled to the third gear (25), and wherein a fourth gear (31) is preferably arranged on the rotational axis of the third gear (30), offset by 180° from the third gear (30), which fourth gear engages with the two driven gears (18, 19).

Images