STORAGE ARRANGEMENT OF A WOBBLE DISC IN A STEERING GEAR COMPONENT AND SURGICAL INSTRUMENT

Description

[0001] The invention relates to a bearing arrangement of a swashplate in a steering gear component and to a surgical instrument that has such a bearing arrangement.

[0002] Surgical instruments, which can be operated manually or by a robot, are known from the prior art. These instruments feature tools whose tips can be pivoted by means of several interlocking swivel links. These swivel links are connected to a multitude of guide wires or cables to achieve precise control of the tool tip. Using many thin guide wires, as opposed to a few thicker ones, results in a more uniform force distribution in all directions of angulation.

[0003] From US 5,454,827 B2 it is known to couple such steering wires with a spatially adjustable disc arranged proximally in an actuating unit, which is connected via a rod to a manually operable control lever, so that a movement of the spatially adjustable swashplate causes a corresponding relative movement of the distal pivot members and thus a pivoting of the tool tip.

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

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

[0006] Furthermore, it is known to transmit drive angles to a swashplate in a surgical instrument with a steering gear component for spatial orientation in two degrees of freedom / spatial directions, wherein the steering gear component is rotationally decoupled from the swashplate by a ball bearing. A rotational movement of the instrument shaft is transmitted to the swashplate by means of a cardan bearing on a main shaft, 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 swashplate in a steering gear component of a surgical instrument is known, wherein the swashplate is rotatably mounted about an axis of rotation in a receiving opening of the steering gear component, and wherein the bearing arrangement has a plurality of rolling elements which are balls.

[0008] Furthermore, a storage arrangement according to the preamble of claim 1 is known from WO 2020 / 218920 A2.

[0009] Starting from this state of the art, the object of the present invention is to provide an improved bearing arrangement for a swashplate in a steering gear component with regard to the required installation space, which mounts a swashplate in a steering gear component in a rotationally decoupled manner.

[0010] This problem is solved by a storage arrangement having the features of claim 1.

[0011] The further problem of providing a surgical instrument that has an improved storage arrangement of the spatially adjustable swashplate is solved by the surgical instrument with the features of independent claim 7.

[0012] Further developments and preferred embodiments of the storage arrangement and the surgical instrument are described in the dependent claims.

[0013] According to a first embodiment of the inventive bearing arrangement of a swashplate in a steering gear component, in which the swashplate is rotatably mounted about an axis of rotation in a receiving opening of the steering gear component, the swashplate has an outer circumferential surface that provides a circumferential inner bearing surface. The steering gear component has an inner circumferential surface in the receiving opening that provides a circumferential outer bearing surface, which is arranged axially corresponding to the circumferential inner bearing surface of the swashplate in the bearing arrangement. Furthermore, the bearing arrangement has a plurality of rolling elements, which are balls, wherein the rolling elements form a bearing with the circumferential inner bearing surface and the circumferential outer bearing surface by being circumferentially distributed between the circumferential inner bearing surface and the circumferential outer bearing surface.The large inner and outer bearing surfaces have a cross-section designed to form a four-point bearing, enabling them to absorb axial forces. A number of the rolling elements are selected to provide a full complement bearing. This creates a rolling bearing integrated into the swashplate and steering gear component. Since the bearing arrangement thus eliminates the need for inner and outer races because the bearing surfaces are integrated into the swashplate and steering gear component, less installation space is required, allowing for a compact design. The swashplate itself provides the inner race of the bearing, and the steering gear component provides the outer race.

[0014] The "surfaces" here refer to surface sections of the swashplate 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 not continuous. The "outer circumferential surface" of the swashplate is understood to be its outer surface between the end faces of the swashplate, whereby the "outer circumferential surface" or outer surface of the swashplate can be shaped with different sections. At least one surface section of the "outer circumferential surface" is shaped as the "circumferential inner bearing surface," which forms an inner raceway for the rolling elements of the integrated rolling bearing. The same applies to the "inner circumferential surface" of the receiving opening of the steering gear component with the "circumferential outer bearing surface": The "inner circumferential surface" is understood to be the inner surface of the steering gear component between its front and rear faces, whereby the "inner circumferential surface" orThe inner 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 provides an outer raceway for the rolling elements of the integrated rolling bearing. 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 at an angle or via a radius.

[0015] A four-point bearing design may be preferable, as it is particularly effective at absorbing axial forces occurring during operation in both directions. This is especially important because tilting moments, which are a key load case for a swashplate, can be optimally absorbed and transmitted by a four-point bearing.

[0016] Full spherical bearings are preferred because they can withstand higher loads than caged or separating element designs, and require less space than caged designs and less assembly effort than designs with separating elements.

[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 by the steering gear component having an access bore extending to the circumferential outer bearing surface, which can be closed with a filling plug. Naturally, the access bore has a cross-section adapted to the dimensions of the rolling element to facilitate filling. A filling plug is understood here to be any sealing 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 bore, the swashplate or the steering gear component can be designed in two parts, with a parting line dividing either the circumferential inner bearing surface or the circumferential outer bearing surface. For this purpose, the swashplate can be separated axially at the inner bearing surface, and the steering gear component radially or axially at the outer bearing surface. The filling with the rolling elements takes place in an assembly arrangement of the swashplate and the steering gear component, whereby only the first part of the two-part component is mounted, and the second part, forming the bearing arrangement, is only mounted after filling has been completed.

[0019] Another alternative embodiment for filling the bearing with the rolling elements can provide that the swashplate and the steering gear component are displaceable relative to each other in the direction of the axis of rotation, so that axial displacement creates a gap in the bearing area through which the rolling elements can be inserted. Since a flank or surface section of one of the raceways (outer bearing surface or inner bearing surface) is shaped differently for this purpose, this embodiment is only suitable for limited bearing load absorption. Furthermore, in this embodiment, the inclusion of a locking device is advantageous, ensuring that the assembly gap remains closed during operation.

[0020] Among the filling variants, the embodiment with a closable access bore is preferred, as this avoids design disadvantages such as those that can arise from a two-part design of the swashplate or the steering gear component, or from an unfavorable rolling element guidance in the case of a movable swashplate and steering gear component.

[0021] In a further embodiment, the swashplate 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 section where the shaft diameter is widened to form the spherical contour, and the swashplate has a receiving recess on its inner surface that is contoured at least partially to match the spherical section, so that the swashplate is movably mounted on the shaft about two axes perpendicular to the axis of rotation without axial displacement. To transmit a rotation or a rotation angle of the shaft to the swashplate, two guide grooves are provided on the outer surface of the spherical section of the shaft. These grooves extend diametrically and longitudinally along the shaft and engage with two pins that are arranged diametrically and radially inward on the swashplate or on an inner surface of the swashplate.

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

[0023] In yet another embodiment of the bearing arrangement, the receiving recess in the swashplate can be spherical, corresponding to the spherical section, whereby the receiving recess acts like a socket joint on both sides, thus axially fixing the coupling completely. A two-part design of the swashplate facilitates assembly by mounting the swashplate parts onto the spherical section to complete the swashplate.

[0024] According to an alternative embodiment, the receiving recess in the swashplate has a spherical section and a cylindrical or expanding section, so that the swashplate is only fixed on one side by the spherical section and mounting on the spherical section is made possible by the cylindrical or expanding section pointing towards the spherical section when sliding it onto the shaft.

[0025] The surgical instrument according to the invention, which has a bearing arrangement for a swashplate 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 is particularly suitable for installation in a surgical instrument due to its compact design. The instrument has a main shaft and a hollow shaft extending coaxially to a longitudinal axis of the main shaft. An actuating unit is arranged at the proximal end of the shaft (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 can be actuated via an actuating element mounted axially displaceably in the shaft. This actuating element extends through a longitudinal through-bore in the main shaft and is in operative communication with the actuating unit on its proximal side.The bearing arrangement according to the invention is designed for the spatial alignment of the swashplate with respect to the main shaft in conjunction with a proximal-side drive, such that a movement of the proximal-side drive causes the pivoting of the tool tip.

[0026] The bearing arrangement, via the steering gear component, interfaces with the proximal-side drive to transmit its angle of rotation to the swashplate for controlling the distal tool tip. The spatial alignment of the swashplate relative to the main shaft, achieved by movement of the proximal-side drive, causes the tool tip to pivot. This pivoting motion is achieved via a joint mechanism relative to the longitudinal axis of the shank. In one embodiment, the joint mechanism consists of pivot links arranged at the distal end of the shank. These pivot links are connected to the proximal-side drive via steering wires running longitudinally along the shank. The steering wires are mounted on the swashplate, so that movement of the proximal-side drive causes a corresponding relative movement of the distal-side pivot links, thus pivoting the tool tip.

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

[0028] In this embodiment, the swashplate is coupled to a third gear by the bearing arrangement, which engages with the two drive gears, wherein the steering gear component is a steering ring which is rotationally fixed to the third gear, wherein preferably a fourth gear is arranged on the axis of rotation of the third gear, offset by 180° to the third gear, which engages with the two driven gears, so that the formed toothed chain is closed to form a toothed ring which ensures a uniformly rotating 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 through the following detailed description with reference to the accompanying figures. Objects or parts thereof that are essentially 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. The drawings illustrate an exemplary embodiment of the invention. The drawings, the description, and the claims contain numerous features in combination. It will be advantageous for those skilled in the art to also consider the features individually and combine them into meaningful further combinations.

[0030] This shows: Fig. 1 a schematic perspective side view of a surgical instrument, Fig. 2 a perspective detail view of a prior art swashplate bearing arrangement with a ball bearing for mounting the swashplate 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 made of Fig. 3 , Fig. 5 an exploded view of the side section view from Fig. 4 without rolling elements, Fig. 6 a detailed sectional view D of the bearing arrangement made of Fig. 4 , Fig. 7 a detailed sectional view through the bearing arrangement designed as a four-point bearing made of Fig. 4 , Fig. 8 a bottom view of the storage arrangement made of Fig. 3 Fig. 9 a perspective partial sectional view of the swashplate arranged on a spherical section of a main shaft, which is designed for bearing in a steering ring of a drive for a surgical instrument according to the invention, Fig. 10 a partial sectional top view of the swashplate arranged on the spherical section of the main shaft made of Fig. 8 , and Fig. 11 a perspective view of a swashplate 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 Figure 1 schematically shows a surgical instrument 1 with a hollow shaft 2, an actuating unit 4 (shown only schematically) arranged at the proximal end 3 of the shaft 2, and a tool tip 6 at the distal end 5 of the shaft 2. The tool tip 6 has a tool that can be actuated via an actuating element 8, which is axially displaceable within the shaft 2 and is in operative connection with the actuating unit 4 on its proximal side. The actuating unit 4 can be a manually operated handle or a unit designed for robotic use, i.e., one that can be actuated without manual intervention. The tool 7 of the tool tip 6 can, for example, be a tool equipped with jaws, as shown in Figure 1. Fig. 1 The tool tip 6 is depicted, or it may be an endoscope, an applicator, or the like. The tool tip 6 is pivotable relative to the longitudinal axis 10 of the shaft 2 via a joint mechanism 9. The joint mechanism 9 consists of pivot links 11 arranged at the distal end of the shaft 5, which are connected via guide wires 12 running longitudinally along the shaft 2 to a drive 13 arranged at the proximal end 3 of the shaft 2 such that a movement of the proximal drive 13 causes a corresponding relative movement of the distal pivot links 11 and thus a pivoting of the tool tip 6. Although only the term guide wires 12 is used above and below, the term steering cables can also be used functionally, which is why the term guide wires 12 should also be read and understood synonymously as steering cable.

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

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

[0034] In the case of surgical instrument 1 according to Fig. 1 (combined with Fig. 2 - State of the art - or Fig. 3 bis 11 - In the 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 axially displaceable within this hollow main shaft 21.

[0035] The steering wires 12 exiting the shaft 2 at its proximal end 3 are guided at the distal end of the main shaft 21 and can be fanned out by means of a fan-shaped washer (not shown) arranged non-rotatably on the main shaft 21, thereby increasing the radial distance of the steering wires 12 from the longitudinal axis 10 of the shaft 2. The steering wires 12, running parallel to the longitudinal axis 10 of the shaft 2 behind such a fan-shaped washer, extend to the swashplate 14, to which the steering wires 12 are fixed. For this purpose, the swashplate 14 has an axially parallel through-hole 41 for each steering wire 12, with the steering wires 12 being secured within the through-holes 41 by set screws 41.2 as shown in Fig. 2 or proximally with a clamping disc 41.1, as in Fig. 9 und 10 are shown, can be fixed and can be connected to the swashplate 14 in a force-fit manner.

[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 axis of rotation B intersects the central axis A of the driven gears 18 and 19 as well as 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 swashplate 14 coupled to the third gear 30, thus directly actuating the steering cables 12.In order to close the toothed chain formed by the gears 18, 19 and 30 into a closed toothed ring, which ensures a uniformly rotating force distribution, a fourth gear 31 is arranged on the axis of rotation B of the third gear 30, offset by 180° to the third gear 30, which engages with the two driven gears 18 and 19, wherein the fourth gear 31 is also preferably designed as a bevel gear.

[0037] The swashplate 14 is in the known bearing arrangement according to Fig. 2 The swashplate 14 is mounted via a (ball) bearing ring 32 in the steering ring 33, which is rotationally fixed to the third gear 30, to allow rotation of the swashplate 14 about the longitudinal axis 10 of the shaft 2. The steering ring 33, which is rotationally fixed to the third gear 30, is freely rotatable relative to the fourth gear 31 via a bearing ring 34 on a bearing sleeve 331, so that rotation of the fourth gear 31 about its axis of rotation B does not cause any rotation of the steering ring 33 and the swashplate 14. However, the use of a standard rolling bearing is only possible with the limitation of increased installation space requirements, which hinders the miniaturization of a surgical instrument equipped with it. Even a thin-section bearing requires more installation space than is available between the steering ring and the swashplate with the desired miniaturization. While a plain bearing meets the installation space requirements, it cannot absorb axial forces.

[0038] The above in relation to Fig. 2 The described embodiments of the drive 13 for spatially aligning the swashplate 14 for controlling the tool tip by means of the guide wires 12 also apply to a surgical instrument 1 according to the invention, which has a bearing arrangement 40 according to the invention, as described in Fig. 3 bis 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 in order to mount the swashplate 14 rotatably about the axis of rotation 10 in the receiving opening 330 of the steering ring 33. As in Fig. 4 bis 6 As can be seen, the bearing raceways are integrated into the swashplate 14 and the steering ring 33 in a space-saving manner. The swashplate 14 has a circumferential inner bearing surface 45.1 on its outer circumferential surface 45, thus fulfilling the function of an inner bearing 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 fulfills the function of an outer bearing ring. The rolling elements 50, which are preferably balls so that the bearing can absorb not only radial but also axial loads, are distributed circumferentially 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, as shown in [reference missing], is preferred. Fig. 7 sketched so that axial loads in both directions can be absorbed, 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 a non-inventive embodiment (not shown), the bearing arrangement can include a bearing cage or separator for uniform spacing of the rolling elements, thereby preventing contact between adjacent rolling elements. This reduces heat generation due to friction and promotes uniform load distribution around the circumference. However, since such cages or separators can lead to increased installation space requirements, a full-sphere design of the bearing arrangement 40 is preferred, which is also capable of withstanding higher loads than a caged design. A full-sphere 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, such that U-(n*D) < D, meaning there are no large gaps between any two adjacent rolling elements.

[0042] In Fig. 8 An access bore 334, sealed by a filling plug 51, can be seen on the steering ring 33 (in Fig. 3 (indicated), which extends to the extensive outer bearing surface 333 (not shown). The access bore 334 allows the bearing raceway formed between the inner bearing surface 45.1 of the swashplate 14 and the outer bearing surface 333 of the steering ring 33 to be filled with the rolling elements 50 before it is closed with a filling plug 51. Replacement can be carried out accordingly by emptying the old rolling elements through the access bore 334 after removing the filling plug 51 and filling in new rolling elements.

[0043] As an alternative to the preferred filling device via access bore 334, a bearing arrangement 40 according to the invention can be filled with rolling elements by making the swashplate 14 or the steering gear component 33 two-part, wherein a parting plane divides the inner bearing surface 45.1 or the outer bearing surface 333 respectively, or by designing the swashplate 14 and the steering gear component 33 at the outer circumferential surface 45 and the inner circumferential surface 332 such that they are displaceable relative to each other in the direction of the axis of rotation 10, so that a gap is created in the area of ​​the inner bearing surface 45.1 or the outer bearing surface 333 through which the bearing can be filled.

[0044] Fig. 9 bis 11 illustrate the mounting of the swashplate 14 on the main shaft 21 of a surgical instrument 1 (cf. Fig. 1 ). The spatial orientation of the swashplate 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 positioning angle of the proximal-side drive (cf. Fig. 2 ). The storage arrangement is structurally simple and compact, and easy to assemble.

[0045] The main shaft 21 has a spherical section 24 for the ball-joint mounting of the swashplate 14. Two guide grooves 22 extend longitudinally along the shaft 21 and are provided on both sides, or diametrically, within the spherical section 24. The swashplate 14 has a receiving recess 44 contoured to at least partially match the spherical section 24. Two pins 42 extend diametrically and radially inward from this recess and engage in the guide grooves 22 on the spherical section 24 of the main shaft 21. For mounting the pins 42, the swashplate 14 can have two diametrically radially extending through-holes 43, allowing the pins 42 to be inserted from the outer side 45 of the swashplate 14 through the through-holes 43 until they emerge on the inner side of the swashplate 14 and project radially inward to the desired length. The through-holes 43 are axially separated from the circumferential inner bearing surface 45.1 spaced 45° apart on the outer perimeter surface, as in . Fig. 9 as can be seen. As an alternative to through-holes 43, in embodiments not shown the pins 42 can be fastened in two diametrically radial blind holes extending from the inside of the swashplate 14, or the pins 42 can be bonded to the inside of the swashplate 14, e.g. manufactured in one piece.

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

[0047] Tilting or rotating the swashplate 14 about one or both axes of rotation A, B relative to the longitudinal axis 10 of the shaft 2 causes the instrument tip 6 to pivot distally relative to the longitudinal axis 10 of the shaft 2 via the steering wires 12. By transmitting a rotational movement of the main shaft 21 about the longitudinal axis 10 of the shaft 2 to the swashplate 14, the tool tip 6, coupled distally to the main shaft 21, can be rotated about the longitudinal axis 10 of the shaft 2.

[0048] In Fig. 10It can be seen that the receiving recess 44 in the example shown consists of a proximal spherical section and a distal cylindrical section, which allows the swashplate 14 to be mounted by sliding it onto the main shaft 21 from the proximal end. Alternatively, a widening section (not shown) can be provided distally instead of a cylindrical section. The swashplate 14 is only fixed on one side to the spherical section by the proximal spherical section, but is held in place by the tension of the steering wires 12, which are passed through the openings 41 and secured with a proximal clamping ring 41.1, thus fixing the swashplate 14 axially.In a modified embodiment, also not shown, the receiving recess 44 of the swashplate 14, corresponding to the spherical section 24, can be designed without a cylindrical or expanding section, consisting solely of a spherical section, so that the ball-joint bearing is axially completely fixed. However, this embodiment requires a swashplate 14 to be made of at least two parts to allow mounting on the spherical section 24.

[0049] The drawings illustrate an embodiment of the invention. The drawings, the description, and the claims contain numerous features in combination. It is advantageous for those skilled in the art to also consider the features individually and combine them into meaningful further combinations. The present invention provides a bearing arrangement 40 for 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. The swashplate 14 has an outer circumferential 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.Furthermore, the bearing arrangement 40 comprises a plurality of rolling elements 50, which are distributed circumferentially 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 together form an integrated rolling bearing of the bearing arrangement 40. A surgical instrument 1 comprising the bearing arrangement 40 is also disclosed. REFERENCE MARK LIST

[0050] 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 Ball 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 socket 332, 333 Inner circumferential surface, outer bearing surface 334, 335 Access hole, mounting foot 40 Bearing arrangement 41, 41.1, 41.2 Through hole, mounting washer, setscrew 42 Pin 43, 44 Mounting hole, mounting recess 45, 45.1 Outer circumferential surface, inner bearing surface 50 Rolling element 51 Filler plug

Claims

1. Bearing assembly (40) of a swash plate (14) in a steering mechanism component (33) of a surgical instrument (1), wherein the swash plate (14) is mounted in a receiving opening (330) of the steering mechanism component (33) so as to be rotatable about a rotational axis (10), wherein the bearing assembly (40) has a plurality of rolling elements (50) which are spheres (50), wherein the swash plate (14) has an outer circumferential surface (45) which provides a circumferential inner bearing surface (45.1), and the steering mechanism 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 accommodated so as to be circumferentially distributed between the circumferential inner bearing surface (45.1) of the swash plate (14) and the circumferential outer bearing surface (333) of the steering mechanism component (33), such that an integrated roller bearing of the bearing assembly (40) is provided by the swash plate (14), the steering mechanism component (33) and the plurality of rolling elements (50), characterized in that the circumferential inner bearing surface (45.1) and the circumferential outer bearing surface (333) have a cross section for forming 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-complement ball bearing.

2. Bearing assembly (40) according to claim 1, characterized in that - the steering mechanism component (33) has an access bore (334) which extends to the circumferential outer bearing surface (333) and which can be closed with a filling plug (51), or - the swash plate (14) or the steering mechanism 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) in each case, or - the swash plate (14) and the steering mechanism component (33) are movable relative to one another in the direction of the rotational axis (10).

3. Bearing assembly (40) according to claim 1 or claim 2, characterized in that the swash plate (14) is arranged on a shaft (21) which defines the rotational axis (10), wherein the shaft (21) has a spherical portion (24) for supporting the swash plate (14), and the swash plate (14) has a receiving recess (44) which is contoured so as to be at least partially adapted to the spherical portion (24), wherein - the spherical portion (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), such that an angle of rotation of the shaft (21) can be transferred to the swash plate (14).

4. Bearing assembly (40) according to claim 3, characterized in that the receiving recess (44) is spherical in shape, corresponding to the spherical portion (24), wherein the swash plate (14) is designed in two parts, or the receiving recess (44) has a spherical portion (45) and a cylindrical or widening portion (46).

5. Surgical instrument (1) comprising a bearing assembly of a swash plate (14) in a steering mechanism component (33), characterized in that the bearing assembly is a bearing assembly (40) according to at least one of claims 1 to 4.

6. Surgical instrument (1) according to claim 5, characterized in that the surgical instrument (1) is formed with a main shaft (21) running coaxially to a hollow sheath (2) and has an actuating unit (4) arranged at the proximal end (3) of the sheath (2) and a tool tip which is (6) arranged at the distal end (5) of the sheath (2) and has a tool (7) which can be actuated by an actuating element (8) mounted in an axially movable manner in the sheath (2), which element extends through a longitudinally 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 sheath (2) via a joint mechanism (9), and the joint mechanism (9) is operatively connected to a proximal-side drive (13) which has the swash plate (14).

7. Surgical instrument (1) according to claim 5 or claim 6, characterized in that the joint mechanism (9) consists of pivoting members (11) arranged at the distal end (5) of the sheath (2), which are connected to the proximal-side drive (13) via steering wires (12) running in the longitudinal direction of the sheath (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 in that the proximal-side drive (13) is designed as a motorized drive (13) having at least two drive wheels (18, 19) between which the swash plate (14) is arranged.

9. Surgical instrument (1) according to claim 8, characterized in that the swash plate (14) is coupled by the bearing assembly (40) to a third gear (30) which is in engagement with the two drive wheels (18, 19), wherein the steering mechanism component (33) is a steering ring (33) which is coupled to the third gear (25) for conjoint rotation, 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 is in engagement with the two driven gears (18, 19).