DE102021119532A1 - Surgical instrument and transmission device therefor - Google Patents

Abstract

The present invention provides a transmission device for a surgical instrument (1). The gear device (100) can be connected in the actuating unit (4) to the drive (40), the drive axis of rotation (D) of which deviates from the main axis (A) of the instrument, and has a gear disc (104) with which, in an assembly arrangement of the gear device ( 100) in the surgical instrument (1), the main shaft (8) can be actuated in rotation, with an axis of rotation (B) of the gear disk (104) running parallel to the main axis (A) of the instrument in the mounting arrangement, and with the gear disk (104) in the mounting arrangement can be brought into operative connection with a gear ring (19) which is connected to the main shaft (8). According to the invention, the transmission device (100) has a cardan shaft (101) with two cardan joints (102, 103), a first cardan shaft section (106) being connected via a first cardan joint (102) to an intermediate shaft section (105) which is connected via a second cardan joint (103) is connected to a second articulated shaft section (109). The first articulated shaft section (106) is connected to the gear disk (104) in a rotationally fixed manner with respect to the axis of rotation (B) and the second articulated shaft section (109) can be brought into operative connection with the drive (40). Furthermore, a surgical instrument with such a gear device is provided.

Description

The invention relates to a gear device for a surgical instrument and the surgical instrument itself.

Surgical instruments are known from the prior art, which can be guided manually or by a robot and have a shaft arrangement, at the proximal end of which a handle or actuation unit is arranged and at the distal end of which a tool is arranged. A shaft assembly may comprise a hollow shaft in which is disposed a hollow main shaft extending coaxially with the longitudinal axis of the shaft, rotatable about the longitudinal axis of the shaft and extending beyond the proximal end of the shaft into the actuator unit. A rotation of the main shaft about the longitudinal axis causes a corresponding rotation of the tool coupled to the main shaft on the distal side about the longitudinal axis. An actuating element for actuating the tool, e.g. B. for opening and closing, which also extends into the actuating unit on the proximal side. Furthermore, in order to angle the distal tool tip relative to the longitudinal axis of the shank, a joint mechanism arranged at the distal end of the shank and made up of pivoting members can be actuated in a manner similar to that of a vertebral column by steering wires arranged around it. For this purpose, the steering wires in the actuation unit can be fastened to a swash plate mounted on the main shaft, via which swash plate the pivoting of the tool tip is controlled spatially.

Out of U.S. 7,699,855 B2 an adapter is known as an interface for connecting a surgical instrument to a robotic arm. The drives for all functions of the instrument are located on the side of the robot, with clutch discs in a common parting plane ensuring the transmission of the drive angles of rotation. The axes of rotation of the clutch discs are perpendicular to the longitudinal axis of an instrument shaft. A gear for transferring the rotary movement of a clutch disk through 90° into a rotary movement of an instrument shaft is not described in detail.

Also US10105128 describes the possibility of a rotary coupling of an instrument shaft with the handle, without elaborating on this, but focusing on the alignment mechanism for a swash plate.

The surgical instrument also has an interface for connecting to a robot WO 2014/004242 A1 is revealed. The surgical instrument there has a tool attachment section for operational coupling to the drives of the robot, which is equipped with a gear mechanism for the rotary actuation of the shaft arrangement, which has a first gear wheel which is rotatably mounted on a mounting plate perpendicular to the shaft axis and has a bevel gearing with a second gear wheel is in meshing engagement, the axis of rotation of which is parallel to the shaft axis. The second transmission gear, in turn, meshes with a sprocket portion of the shaft assembly. The first transmission gear meshes with a drive wheel, which is coupled to a drive motor of the robot via a drive member. In this way, a rotational movement of the drive motor of the robot is transmitted via the drive wheel to the first gear wheel, and from this to the second gear wheel which is bevel-toothed therewith and which ultimately transmits the rotation of the drive wheel to the ring gear section of the shaft.

When using a pair of bevel gears to transmit the drive for the rotation of the shaft, it is difficult to set the center distances exactly. Even slight misalignments can lead to the destruction of the bevel gears. This requires low manufacturing and assembly tolerances given the relatively complex geometry of the bevel gears, which is associated with high costs.

Proceeding from this state of the art, it is the object of the present invention to provide an improved transmission for a surgical instrument for transferring the rotational movement of a drive into a rotational movement of a main shaft mounted in a shaft.

This object is achieved by a transmission device having the features of claim 1.

Preferred embodiments are set out in the subclaims.

The further object of providing a correspondingly improved surgical instrument is solved by the surgical instrument having the features of independent claim 10 .

The transmission device according to the invention is designed for a surgical instrument which has a shank, an actuating unit arranged at the proximal end of the shank and a tool arranged at the distal end of the shank. The tool is controllable by means of a drive associated with the operating unit, via a main shaft which is coaxial with a main instrument axis A defined by the shank and rotates about the main instrument axis A is stored in cash. The main shaft is rotatably disposed in the hollow shaft. The transmission device can be connected in the actuation unit to the drive, the drive axis of rotation D of which deviates from the instrument axis A, for example running perpendicular to the main axis A of the instrument. Furthermore, the gear device has a gear disk with which the main shaft can be rotationally actuated in a mounting arrangement of the gear device in the surgical instrument. For this purpose, the gear disk is brought into operative connection with a gear ring, which is connected to the main shaft, so that an axis of rotation B of the gear disk runs parallel to the main axis A of the instrument. According to the invention, the transmission device has a cardan shaft with two cardan joints, a first cardan shaft section being connected via a first cardan joint to an intermediate shaft section, which in turn is connected to a second cardan shaft section via a second cardan joint. The first articulated shaft section is connected to the gear disk in a rotationally fixed manner with respect to the axis of rotation B, while the second articulated shaft section can be brought into operative connection with the drive.

The transmission device according to the invention, based on two cardan joints, enables power to be transmitted between the drive and the main shaft as two spatially separate components whose axes of rotation are not aligned. The articulated shaft of the transmission device transmits the driving force or rotational movement of the drive about the drive axis D, which does not lie in the main instrument axis A, to the gear disk, the axis B of which lies parallel to the main instrument axis A. This axial distance is bridged by the operative connection between the gear pulley and gear ring. Because of its simple construction, the transmission device according to the invention is cheaper to manufacture and purchase than a pair of bevel gears. Furthermore, by varying the length of the joint sections and the deflection angle of the cardan joints, the transmission device according to the invention enables almost any orientation of the drive axis of rotation D in relation to the main instrument axis A and thus almost any arrangement of the drive motor, which is an optimal arrangement in relation to the available construction space allows.

The intermediate shaft section, which is connected via the cardan joints to the first cardan shaft section and the second cardan shaft section, extends along a connecting axis of rotation C, which in the case of angled cardan joints spans an angle with the axis of rotation B of the transmission disc and with the axis of rotation D of the drive. In order to minimize unevenness in the transmission of rotation with angled cardan joints (cardan error: constant rotational speed of a drive shaft does not lead to constant rotational speed of an output shaft), the deflection angles can be kept as small as possible. Additionally or alternatively, with larger deflection angles, both deflection angles can be chosen to be the same size in order to obtain the most uniform possible power transmission. In addition, to minimize the fluctuations in the angular velocities between the input and output shafts, it is advantageous if the connecting axis of rotation C of the intermediate shaft section lies in a common plane with the axis of rotation B of the transmission disk and with the axis of rotation D of the input. If the deflection angles are the same and bend in opposite directions, the axis of rotation B of the gear disk (and thus also the main axis A of the instrument) and the axis of rotation D of the drive run parallel. If both deflection angles bend in the same direction, for example by 45° each, the deflection angles add up to the angle between the axis of rotation B of the gear disk (and thus also the main instrument axis A) and the drive axis of rotation D, so that for the example mentioned of two deflection angles with 45 ° the axis of rotation B of the gear disc (and thus also the main axis A of the instrument) is vertical, i. H. perpendicular to the drive axis of rotation D runs.

In a further, preferred embodiment of the transmission device according to the invention, it is provided that a position of the cardan joints of the cardan shaft can be adjusted in relation to one another, in relation to the transmission disk and to the drive. In this way, tolerance compensation can take place, so that the transmission device provides a backlash-free connection between the transmission disk and a drive shaft of the drive. For this purpose, the two cardan joints can be mounted such that they can be displaced in relation to one another in order to compensate for possible angle errors due to manufacturing tolerances.

According to a further embodiment of the transmission device according to the invention, the intermediate shaft section, which defines the connection axis of rotation C, can have a third cardan shaft section, which is connected to the first cardan shaft section via the first cardan joint, and a fourth cardan shaft section, which is connected to the second cardan shaft section via the second cardan joint . The third articulated shaft section and the fourth articulated shaft section are connected to one another in a rotationally fixed manner with respect to the connection axis of rotation C at their respective ends remote from the joint. Preferably, the non-rotatable connection of the third articulated shaft section to the fourth articulated shaft section can be provided by a pivot connection, which has a shaft journal which in the shaft journal receiving space is arranged. For this purpose, the shaft journal, which extends along the connection axis of rotation C, is formed on the end of one of the two connection partners which is remote from the joint and consists of the third and fourth articulated shaft section. At the end remote from the joint of the other of the two connection partners, which are the third and fourth articulated shaft section, a shaft journal receiving space is formed, which also extends along the connection axis of rotation C. That is, the shaft journal receiving space in the third articulated shaft section is formed to extend from the far end when the shaft journal is at the far end of the fourth articulated shaft section, and vice versa, the shaft journal receiving space in the fourth articulated shaft section is formed to extend from the far end , when the shaft journal is formed at the end of the third joint shaft section remote from the joint. A length of the intermediate shaft section can be adjusted by an arrangement depth of the shaft journal in the shaft journal receiving space. The position of the cardan joints in relation to one another is adjusted with the length of the intermediate shaft section.

The non-rotatable connection of the third articulated shaft section to the fourth articulated shaft section, which together form the intermediate shaft section, can be realized by positive locking, non-positive locking or a combination of positive and non-positive locking between the journal and journal receiving space. In one embodiment of the transmission device according to the invention, the non-rotatable connection can be a positive connection of the shaft journal in the shaft journal receiving space, the shaft journal and the shaft journal receiving space having a corresponding cross-sectional profile that deviates from a circular shape. Alternatively or additionally, in order to fix the length of the intermediate shaft section set by the arrangement depth, the non-rotatable connection can be designed as a non-positive connection by means of at least one locking pin, with the locking pin being arranged in a transverse bore located in the connection partner that has the shaft journal receiving space , perpendicular to the journal receiving space. The non-positive or frictional connection is produced in that the locking pin makes perpendicular contact with the shaft journal accommodated in the shaft journal receiving space and generates a normal force that determines the frictional force. As an alternative to this, if the transverse bore intersects the pin-receiving space as a through-hole, two locking pins can be used, which are inserted from both sides into the through-hole until contact is made with the received pin, in order to act diametrically on the pin.

A further embodiment of a transmission device according to the invention provides that the non-rotatable connection of the first articulated shaft section to the transmission disk in relation to the axis of rotation B is also provided by a pin connection, which correspondingly has a transmission pin and a transmission pin receiving space, the transmission pin being arranged in the transmission pin receiving space. A distance of the first cardan joint from the gear disk along the axis of rotation B and thus the position of the first cardan joint in relation to the gear disk can be adjusted by arranging the gear pin in the gear pin receiving space. The gear pin is formed on one of the two connection partners, which consist of the first articulated shaft section and the gear disk, and extends along the axis of rotation B. This means that the gear pin is either at the end of the first articulated shaft section remote from the joint or, as it were, as a stub axle, on the gear disk can. Correspondingly, the gear journal receiving space is formed along the axis of rotation B in the other of the two connection partners, the articulated shaft section and the gear disk. i.e. that the gear pin receiving space is formed axially in the gear disk when the gear pin is at the end of the first articulated shaft section remote from the joint, and vice versa, that the gear pin receiving space is formed in the first articulated shaft section extending from the end remote from the joint when the gear pin is formed on the gear disk.

The non-rotatable connection of the first articulated shaft section to the gear disk can also be realized by positive locking, force locking or both. For a form-fitting connection, the gear pin and the gear pin receiving space can have a corresponding cross-sectional profile that deviates from a circular shape. Alternatively or additionally, in order to fix the distance of the first cardan joint from the gear disk set by the arrangement depth, a non-positive or frictional connection can be provided by means of a locking pin, which is arranged in a transverse bore located in the connection partner that accommodates the gear journal has, extends perpendicularly to the gear pin accommodating space, so that the securing pin perpendicularly contacts the gear pin accommodated in the gear pin accommodating space and generates a normal force which determines the frictional force. As an alternative to this, if the transverse bore intersects the pin receiving space as a through-hole, two locking pins can be used, which can be inserted from both sides into the through-hole until the contact is made taken pin are inserted to act diametrically on the pin.

Yet another embodiment of a transmission device according to the invention provides that the operative connection of the second articulated shaft section to the drive in the mounting arrangement is also a non-rotatable connection with respect to the drive axis of rotation, the second articulated shaft section in the mounting arrangement being rotationally fixed to a drive shaft of the drive or to a clutch disk is connected, which is designed for non-rotatable coupling to the drive shaft of the drive. The non-rotatable connection of the second articulated shaft section to the drive shaft or to the drive interface can preferably also be provided here by a pin connection, which in this case has a drive pin and a drive pin receiving space, the drive pin being arranged in the drive pin receiving space and a distance between the second cardan joint and the drive shaft or the clutch disc along the drive axis of rotation D and thus the position of the second cardan joint in relation to the drive can be adjusted by arranging the drive pin in the drive pin receiving space at a depth. The drive pin is formed on one of the connection partners, which are the second articulated shaft section and the drive shaft or the second articulated shaft section and the clutch disk, and extends along the drive axis of rotation D. Corresponding to this is the drive pin receiving space, which extends along the drive axis of rotation D, in the respective other connection partner, d. H. formed in the second drive shaft section or the drive shaft or the clutch disc. The drive pin receiving space is thus formed axially in the drive shaft or the clutch disc when the drive pin is at the end of the second articulated shaft section remote from the joint, and vice versa, the drive pin receiving space is formed in the second articulated shaft section extending from the end remote from the joint when the drive pin is located on the drive shaft or The clutch disc is formed.

The non-rotatable connection of the second articulated shaft section to the drive shaft or the clutch disc can also be a positive connection, in which the drive pin and the drive pin receiving space have a corresponding cross-sectional profile that deviates from a circular shape, and/or for fixing the spacing of the second universal joint set by the arrangement depth from the drive, a frictional connection by means of a locking pin, which is arranged in a transverse bore, which extends in the connection partner, which has the drive pin receiving space, perpendicularly to the drive pin receiving space. A normal force determining the frictional force is generated by contact of the locking pin with the drive pin accommodated in the drive pin receiving space. As an alternative to this, if the transverse bore intersects the pin-receiving space as a through-hole, two locking pins can be used, which are inserted from both sides into the through-hole until contact is made with the received pin, in order to act diametrically on the pin.

In a further embodiment of a transmission device according to the invention, the transmission disk of the transmission device in the assembly arrangement forms a spur gear with the gear ring which is connected to the main shaft, the transmission disk being formed by a spur gear and the gear ring by a spur ring which meshes with the spur gear , to be provided. Gear spur gear and spur gear ring can preferably be straight-toothed, since straight-toothed gearing is easier to manufacture than helical gearing, has lower friction during operation, and allows less complex storage, since no axial forces occur. However, helical or herringbone gears are not excluded. Furthermore, in a less preferred embodiment, it is conceivable that the gear disk in the assembly arrangement with the gear ring can form a traction drive, the operative connection between the gear disk and the gear ring being provided by a traction means such as a chain, a cable or a belt.

Another subject according to the invention is a surgical instrument which, in a first embodiment, has a shaft, an actuating unit arranged at the proximal end of the shaft and a tool arranged at the distal end of the shaft. The tool can be controlled by means of a drive, which is assigned to the actuating unit, via a main shaft which is mounted coaxially to a main instrument axis A, which is defined by the shaft, and is rotatable about the main instrument axis A. Preferably, the shank may be a hollow shank such that the main shaft is rotatably disposed in the hollow shank. The surgical instrument has a gear device in an embodiment according to the invention, the gear device in the actuating unit being connected to the drive, the drive axis of rotation D of which deviates from the main axis A of the instrument, for example running perpendicular thereto. For the rotational actuation of the main shaft, the gear device has a gear disk which is in operative connection with a gear ring which is connected to the main shaft, the axis of rotation B of the gear bescheibe runs parallel to the main instrument axis A. The transmission device according to the invention used in a surgical instrument according to the invention, which is based on a cardan shaft with two cardan joints having the transmission disk at one end and a connection point for driving at the other end, forms a unit that can be assembled at any stage of the assembly process of the surgical instrument or can be dismantled.

Other embodiments, as well as some of the advantages associated with these and other embodiments, will become apparent and better 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 given the same reference numbers. The figures are only a schematic representation of an embodiment of the invention.

• 1 eine schematische perspektivische Seitenansicht eines chirurgischen Instruments,
• 2 eine Seitenansicht auf ein erfindungsgemäßes chirurgisches Instrument mit einer erfindungsgemäßen Getriebevorrichtung,
• 3 eine perspektivische Ansicht der Betätigungseinheit aus 2,
• 4 eine perspektivische Ansicht einer Gelenkwelle einer erfindungsgemäßen Getriebevorrichtung in zwei Einstellungsvarianten a) und b),
• 5 eine Draufsicht auf die Gelenkwelle aus 4 in den zwei Einstellungsvarianten a) und b),
• 6 eine Seitenschnittansicht durch die Gelenkwelle aus 5 in den zwei Einstellungsvarianten a) und b) entlang der jeweiligen Schnittlinie AA,
• 7 eine schematische Seitenschnittansicht einer erfindungsgemäßen Getriebevorrichtung für ein chirurgisches Instrument in einer bevorzugten Ausführungsform, und
• 8 schematische Seitenschnittansichten alternativer Ausführungsformen a), b), c) einer erfindungsgemäßen Getriebevorrichtung für ein chirurgisches Instrument.

show:

• 1 a schematic perspective side view of a surgical instrument,
• 2 a side view of a surgical instrument according to the invention with a transmission device according to the invention,
• 3 a perspective view of the actuation unit 2 ,
• 4 a perspective view of a cardan shaft of a transmission device according to the invention in two setting variants a) and b),
• 5 a top view of the cardan shaft 4 in the two setting variants a) and b),
• 6 a side sectional view through the propeller shaft 5 in the two setting variants a) and b) along the respective cutting line AA,
• 7 a schematic sectional side view of a transmission device according to the invention for a surgical instrument in a preferred embodiment, and
• 8th schematic side sectional views of alternative embodiments a), b), c) of a transmission device according to the invention for a surgical instrument.

1 shows schematically a surgical instrument 1 according to the invention with a hollow shank 2, which defines the main axis A of the instrument, a handle or actuating unit 4 (only shown schematically) arranged at the proximal end 3 of the shank 2, and with a tool 6 arranged at the distal end 5 of the shank 2 , which is designed here as a gripping tool with two jaw parts. The tool 6 on the distal side can be actuated via various actuating mechanisms in the actuating unit 4 on the proximal side, which is preferably designed for robotic use with motor drives and can therefore be a structural unit that can also be actuated without manual intervention—which is advantageous for the reproducibility of the actuation. Arranged in the shank 2 is a main shaft 8 which extends coaxially to the longitudinal axis A of the shank 2, which can be rotated about the longitudinal axis A of the shank and extends beyond the proximal end 3 of the shank 2 into the actuating unit 4, which acts as an actuating mechanism for rotating the Main shaft 8 has a transmission device 100 according to the invention, which is motor-driven. By rotating the main shaft 8, a corresponding rotation of the tool 6 is actuated.

Within the main shaft 8, which is also hollow in this example, an actuating element 9 is mounted in an axially displaceable manner, which extends out of the main shaft 8 on the proximal side in the actuating unit 4, so that a surgical instrument 1 according to the invention with a further motor-driven actuating mechanism for opening and closing the tool 6 can be used axial displacement of the actuating element 9 in the hollow main shaft 8 can be formed.

Another, also motor-driven actuating mechanism can be configured in a surgical instrument 1 according to the invention, for example for pivoting the tool 6 relative to the longitudinal axis A of the shaft 2 via a joint mechanism 7 at the distal instrument tip. For this purpose, steering wires 12 can be used, which extend through the hollow shaft 2, emerge at the proximal end 3 of the shaft 2 and are attached to a spatially adjustable swash plate 17. By increasing the radial distance of the steering wires 12 from the longitudinal axis A, the adjustment angle of the swash plate 17 required for pivoting the tool 6 is reduced. The serrated lock washer 18 arranged distally to the swash plate 17 ensures that the steering wires 12 run parallel to one another and to the longitudinal axis A of the swash plate 17, as a result of which assembly and manufacture are simplified. A variant that is not shown dispenses with the serrated lock washer, so that the steering wires 12 run directly to the swash plate, the radial distance from the longitudinal axis A also being increased, but the steering wires meet the swash plate at an angle. The variant without a serrated lock washer advantageously requires less installation space.

The spatial alignment of the swash plate 17 takes place via a swash plate mechanism 10, which is not described in detail here, and in 1 as the transmission device 100 according to the invention is indicated only schematically. Also that in 2 The exemplary surgical instrument 1 shown has at the distal end 5 of the shaft 2, which defines the main axis A of the instrument, a tool 6 made of two jaw parts that can be pivoted via a joint mechanism 7. At the proximal end 3 of the shaft 2, which is surrounded by a housing component 31 here, the actuating unit 4 connects, which is also shown in 3 is shown. In 2 and 3 a swash plate gear 10 can be seen in the actuating unit 4 next to the gear device 100 according to the invention. The swash plate mechanism 10 comprises two drive wheels 13 which are offset from one another by 180° and which in the example shown are designed as double wheels, each with a spur gear rim and a bevel gear rim. Each drive wheel 13 is driven separately by a drive motor (not shown) and is connected via its spur gear rim to a respective pinion 14 which can be connected to the respective drive motor via a drive shaft 15 on a coupling element 16 . The two drive wheels 13 with a steering bevel gear offset by 90° (not in 2 and 3 to see) engaged, which is arranged on a common axis with the bevel gear 11, which closes the ring gear around the swash plate 17. The steering bevel gear is coupled to the swash plate 17 via a steering ring (not shown) in order to transmit the movements of the drive wheels 13 via the steering bevel gear and the steering ring to the swash plate 17 for their spatial alignment. The steering ring is therefore pivoted with respect to the bevel gear 11 to permit rotation of the steering ring relative to the bevel gear 11 as the steering ring is moved through the steering bevel gear to spatially align the swashplate 17 and actuate the steering wires 12 accordingly. In order to also allow rotation about the longitudinal axis A of the swash plate 17 mounted on the main shaft 8 with the main shaft 8, which is actuated by a transmission device 100 according to the invention, the swash plate 17 is rotatably mounted in the steering ring.

In contrast to the example shown, a surgical instrument 1 according to the invention, which has a gear device 100 according to the invention, can also have alternative actuating mechanisms for pivoting the tool tip and is not limited to the swash plate gear 10 shown for the spatial alignment of the swash plate, to which steering wires are attached, in particular not to the exemplary drive of the swash plate gear by means of spur gearing of the drive wheels 13 in the respective engagement with the pinion connected to a motor. Furthermore, a surgical instrument 1 according to the invention can also have a tool 6 other than that shown, for example an endoscope or an applicator, etc., at the distal shaft end 5 . In principle, a surgical instrument 1 according to the invention, which has a transmission device 100 according to the invention, which controls a rotational movement of the main shaft 8, is not limited to being combined with a joint mechanism 7, which can be controlled by an actuating mechanism in the handle 4, for pivoting the tool 6 at the instrument tip . However, a preferred embodiment of a surgical instrument 1 according to the invention not only has a transmission device 100 according to the invention, but also an actuating mechanism, for example a swash plate mechanism 10, for controlling a joint mechanism 7 for pivoting the tool 6 at the instrument tip. As a result, a bending movement of the tool 6, controlled by an actuating mechanism such as the swash plate gear 10, can be coupled with a rotational movement which is actuated by rotation of the main shaft 8 by means of the gear device 100 according to the invention. In the case of a swash plate mechanism 10, the swash plate 17 can be rotationally coupled to the main shaft 8 for this purpose.

A transmission device 100 according to the invention, as exemplified in 2 and 3 in an installed state can be shown in the handle 4 of a surgical instrument 1, has a gear disk 104 designed here as a spur gear for rotary actuation of the main shaft 8, the axis of rotation B of which runs parallel to the main axis A of the instrument. The gear disk 104 is part of the gear device 100 and is in meshing engagement with a gear ring 19 designed as a spur gear ring, which is non-rotatably connected to the main shaft 8 in order to transmit a rotational movement of the gear disk 104 to the main shaft 8 . The surgical instrument 1 has a bearing housing 131 on a housing component 30 that is positioned appropriately for the rotatable mounting of the main shaft 8 with the gear ring 19 and the gear disk 104 .

According to the invention, the transmission disk 104 is coupled in a rotationally fixed manner to a cardan shaft 101 with two cardan joints 102, 103, which in an exemplary embodiment is shown in FIG 4 until 6 is shown in detail. The cardan shaft 101 is at the other end 2 and 3 with a clutch disc 140, with which the transmission device 100 in the handle 4 of the surgical instrument 1 with a (not shown ten) Drive 40 can be connected, which is broken down in the schematic representations of a transmission device 100 in 7 and 8th is indicated. By using the articulated shaft 101 with the two cardan joints 102, 103, the drive axis of rotation D can deviate from the main axis A of the instrument and, for example, as in 2 and 3 perpendicular, ie at right angles to the main axis A of the instrument. The cardan shaft 101 consists of a first cardan shaft section 106 which is connected to the transmission disc 104 and which is coupled to an intermediate shaft section 105 via the first cardan joint 102 . The intermediate shaft section 105 is in turn coupled via the second cardan joint 103 to a second cardan shaft section 109 which, for example, is connected to a drive motor 40 via a clutch disc 140 (cf. 7 and 8th ) can be brought into effective connection. Each universal joint 102, 103 has a central cross 110 with two perpendicularly crossing axle members 111, 112, the ends of each axle member 111, 112 being received in bores (not numbered) formed at a respective fork end 116, 117, 118, 119 formed joint end of the joint sections 106, 107, 108, 109 are formed. In the example shown, which is not to be understood as limiting, in the first cardan joint 102 the axle element 111 is accommodated in the bores at the fork end 106 of the first articulated shaft section 106 and the axle element 112 perpendicular thereto is accommodated in the bores at the fork end 117 of the third articulated shaft section 107. With the second cardan joint 103 that is Axle element 111 is accommodated in the bores at the fork end 119 of the second articulated shaft section 109 and the axle element 112 perpendicular thereto is accommodated in the bores at the fork end 118 of the fourth articulated shaft section 108.

4 until 6 shows the structure of the articulated shaft 101 of a transmission device 100 according to the invention in a particularly preferred embodiment, in which the length of the intermediate shaft section 105 can be adjusted so that tolerances can be compensated for in order to provide a backlash-free connection between the transmission disk 104 and the drive 40. For this purpose, the intermediate shaft section 105 consists of a third articulated shaft section 107 and a fourth articulated shaft section 108, which can be displaced relative to one another, so that the position of the cardan joints 102, 103 can be adjusted in relation to one another. 4a , 5a , 6a and 4b , 5b , 6b show the cardan shaft 101 in different views with a) third and fourth cardan shaft sections 107, 108 pushed apart and b) third and fourth cardan shaft sections 107, 108 pushed together, so that the intermediate shaft section 105 of the cardan shaft 101 is longer in a) than in b). In the example shown, the third cardan shaft section 107, which is connected to the first cardan shaft section 106 via the first cardan joint 102, and the fourth cardan shaft section 108, which is connected to the second cardan shaft section 109 via the second cardan joint 103, are connected at their ends remote from the joint by a pin connection similar to a telescopic shaft coupled to one another in a rotationally fixed manner.

The non-rotatable pivot connection of the third articulated shaft section 107 with the fourth articulated shaft section 108 has a shaft journal 113a and a shaft journal receiving space 115a, the length of the intermediate shaft section 105, which is formed by the third and fourth articulated shaft sections 107, 108, depending on the arrangement depth of the shaft journal 113a in the Shaft journal receiving space 115a is determined. In the example of 4 until 6 the shaft journal 113a is formed at the end of the fourth articulated shaft section 108 that is remote from the joint, i.e. at the end facing away from the second cardan joint 103 or the fork end 118, and extends axially along the connection axis of rotation C, which is defined by the axis of rotation of the intermediate shaft section 105. Correspondingly, the shaft journal receiving space 115a is formed in the third cardan shaft section 107 and extends axially along the connection axis of rotation C from the end of the third cardan shaft section 107 that is remote from the joint, i.e. from the end facing away from the first cardan joint 102 or the fork end 117, through the third cardan shaft section 107 in the example shown up to the fork end 117. For the non-rotatable coupling, the shaft journal 113a and the shaft journal receiving space 115a have a corresponding cross-sectional profile that deviates from the circular shape, which—indicated by the dashed lines of the shaft journal 113a in 4a and the journal receiving space 115a in 6a - here should be a hexagonal profile. this is in 5b recognizable for the drive pin receiving space 115c in the second articulated shaft section 109, which is provided for forming a pin connection with a drive pin 113c, which is attached to a drive component (e.g. drive shaft 41 of the drive 40 or a clutch disk 140 connected thereto, cf. 7 ) is designed to provide the non-rotatable connection and to adjust the distance of the second universal joint 103 from the drive 40. The drive pin receiving space 115c extends axially along the drive axis of rotation D from the end of the second articulated shaft section 109 remote from the joint, i.e. from the end facing away from the second universal joint 103 or the fork end 119, through the second articulated shaft section 109 in the example shown to the fork end 119.

In an analogous manner, the non-rotatable connection of the first articulated shaft section 106 to the gear disk 104 can also be produced and the distance between the first cardan joint 102 and the gear disk 104 can be adjusted by means of a corresponding pin connection, in that a gear pin 113b (cf. 7 ) is placed in a gear pin accommodating space 115b formed in the first propeller shaft portion 106. For this purpose, the gear pin receiving space 115b extends axially along the axis of rotation B from the end of the first articulated shaft section 106 remote from the joint, ie from the end facing away from the first cardan joint 102 or the fork end 116, through the first articulated shaft section 106 in the example of FIG 4 until 6 to the end of the fork 116. In the example from 7 the gear disk 104 has an axle stub on the side facing away from the gear journal 113b, which can be rotated by means of a bearing 130 in a bearing housing 131 (cf. 2 , 3 ) is stored. The non-rotatable connection of the second articulated shaft section 109 to the drive 40 can correspondingly be designed as a pin connection for adjusting the distance of the second cardan joint 103 from the drive 40 . The second articulated shaft section 109 can be coupled to the drive 40 directly on a drive shaft 41 of the drive 40, or as shown in FIG 7 indicated via a clutch disk 140 which can be connected to the drive shaft 41 in a torque-proof manner. The clutch disk 140, which can be rotatably mounted in a housing component (not shown) of the handle 41 by means of a bearing 130, can have positive and/or non-positive clutch elements which can be brought into engagement with corresponding clutch elements on the drive shaft 41. The drive pin 113c, which extends along the drive axis of rotation D from the clutch disk 140 (or in an alternative that is not shown, from the drive shaft 41), is accommodated in the drive pin receiving space 115c formed along the drive axis of rotation D, corresponding to the drive pin 113c, at the arrangement depth desired for setting the play. In the example of 4 until 6 the drive pin receiving space 115c extends from the end of the second articulated shaft section 109 remote from the joint through the second articulated shaft section 109 to the fork end 119.

Unlike in 4 until 6 shown, each trunnion connection made up of trunnion and trunnion receiving space can also be formed in the reverse manner on the respective articulated shaft sections 106, 107, 108, 109 or the gear disk 104 and the respective drive component 41, 140 independently of one another. For example, in 7 the shaft journal 113a is formed on the third joint shaft section 107 and the shaft journal receiving space 115a is formed in the fourth joint shaft section 108 . Furthermore, it is not mandatory that a pin receiving space extends completely through the respective articulated shaft section to the fork end and opens there, so that the articulated shaft section is designed as a kind of hollow shaft. A trunnion receiving space may also terminate within a propshaft section and provide a stop for the trunnion. The peg and peg receiving space can also have a cross-sectional shape that differs from the hexagonal profile shown and that deviates from the circular shape in order to provide a form fit for the non-rotatable connection. The term trunnion connection should in no way be understood to be limiting in terms of the shape or length of the trunnion or trunnion receiving space, but merely designate two shaft sections that can be connected in a rotationally fixed manner that allows the length of the connected shaft sections to be varied.

In order to fix the pin connection of the two articulated shaft sections 107, 108 of the intermediate shaft section 105 in the desired length or the length required for tolerance compensation for freedom from play, the connection partner has the pin receiving space in 4 until 6 the third articulated shaft section 107 and in 7 the fourth joint shaft section 108, has a transverse bore 114a which extends perpendicularly to the journal receiving space 115a. The transverse bore 114a can as in the example of 4 until 6 be a through hole with it, as in 4b , 5b As can be seen, a locking pin 120a can be inserted diametrically from each side, which contacts the shaft journal 113a accommodated in the shaft journal receiving space 115a while generating a normal force. The force or frictional connection thus effected fixes the shaft journal 113a at the desired arrangement depth in the shaft journal receiving space 115a. In the 7 The embodiment indicated differs from this in that the transverse bore 114a only extends as far as the shaft journal receiving space 115a, so that a single securing pin 120a is used, which contacts the shaft journal 113a received in the shaft journal receiving space 115a, generating a normal force. To avoid imbalance during rotation, the symmetrical variant can be made with two diametrically opposed locking pins 4 until 6 be preferred.

In an analogous manner, the pivot connections of the articulated shaft 101 with the gear disk 104 and the corresponding drive component 41, 140 can optionally also be secured by means of securing pins 120b, 120c, as is shown in 7 can be seen to the arrangement depth of each To fix pin 113b, 113c in the respective pin receiving space 115b, 115c, whereby the position of the cardan joints 102, 103 in relation to the drive 40 and the gear disc 104 can be adjusted. Unlike in 7 shown, two diametrically arranged locking pins can also be used here to secure the respective pin connection. This optional securing of the pivot connections of the articulated shaft 101 with the gear disk 104 and the corresponding drive component 140 can be dispensed with if the adjustability of the length of the intermediate shaft section 105 is sufficient to compensate for tolerances, as is the case with the articulated shaft 101 in the example 4 until 6 shows that also in the in 2 and 3 shown surgical instrument 1 can be seen in the installed state. In the first and second articulated shaft sections 106, 109, this articulated shaft 101 has no transverse bores to the respective journal receiving space 115b, 115c and thus no securing pins.

With the adjustable length of the intermediate shaft section 105 and the optionally adjustable distances of the cardan joints 102, 103 from the gear disk 104 and drive 40, not only can tolerance compensation be carried out, but also the length of the cardan shaft 101 and the deflection angles α, α' on the cardan joints 102, 103 can be optimized in relation to the given installation space conditions.

7 shows (as also in 2 and 3 ) a transmission device 100, in which the deflection angles α, α' on the cardan joints 102, 103 of the cardan shaft 101 are the same size, here 45°, and both cardan joints 102, 103 bend in the same direction, so that the drive axis of rotation D is perpendicular to the axis of rotation B runs. In addition, the connection axis of rotation C lies in one plane with the drive axis of rotation D and the axis of rotation B, which is parallel to the main axis A of the instrument. as this minimizes non-uniformity in the rotary transmission. This also applies to an in 8a shown configuration of a transmission device 100 according to the invention, in which the equal deflection angles α, α' on the two cardan joints 102, 103 bend in opposite directions, so that the drive axis of rotation D runs parallel to the axis of rotation B, but in a plane with the connecting axis of rotation C.

8b and 8c 12 show further configurations of a transmission device 100 according to the invention, which provide alternative arrangement options for the drive 40, but which may be associated with certain non-uniformity in the transmission of rotation, in particular if the deflection angles are large. In 8b the deflection angle α between the drive axis of rotation D and the connection axis of rotation C on the second universal joint 103 deviates from the deflection angle α' between the connection axis of rotation C and the axis of rotation B on the first universal joint 102, with the deflection angle α on the second universal joint 103 being larger in the example shown is the deflection angle α' at the first universal joint 102. And in 8c not only differ the deflection angle α' on the first cardan joint 102 from the deflection angle (not designated) on the second cardan joint 103 (which is spanned between the connection axis of rotation C and the axis of rotation D, which runs perpendicular to the plane of the drawing), but also the three lie Pivot axes B, C and D not in a common plane, since the drive pivot axis D is perpendicular to the plane defined by the connecting pivot axis C and pivot axis B.

Due to the structure of the transmission device according to the invention with the double universal joint shaft, in particular through the longitudinally axially adjustable universal joint shaft sections, axial play can be compensated and installation is significantly simplified. Furthermore, this and skillful adjustment of the joints can ensure concentricity even at high speeds.

Reference List

1

surgical instrument

2

shaft

3

Proximal end of the shaft

4

operating unit

5

distal end of the shaft

6

Tool

7

joint mechanism

8th

main shaft

9

actuator

10

swashplate gear

11

bevel gear

12

steering wire

13

Spur bevel gear

14

pinion

15

drive shaft

16

coupling element

17

swashplate

18

serrated washer

19

gear ring

30, 31

housing components

40, 41

engine, drive shaft

100

gear device

101

cardan shaft

102, 103

universal joint

104

gear wheel

105

intermediate shaft section

106, 107

cardan shaft section

108, 109

cardan shaft section

110

crosspiece

111, 112

axis element

113a,b,c

cones

114a,b,c

cross bore

115a,b,c

spigot receiving space

116, 117

fork end

118, 119

fork end

120a,b,c

locking pin

130

camp

131

bearing housing

140

clutch disc

A

instrument longitudinal axis

B

Axis of rotation of gear wheel

C

Connection axis of rotation intermediate joint shaft section

D

drive axis of rotation

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US7699855B2 [0003]
• US10105128 [0004]
• WO 2014004242 A1 [0005]

Claims (10)

Transmission device (100) for a surgical instrument (1), which has a shank (2), an actuating unit (4) arranged at the proximal end (3) of the shank (2) and an actuating unit (4) arranged at the distal end (5) of the shank (2). Tool (6) which can be controlled by means of a drive (40) assigned to the actuating unit (4) via a main shaft (8) which is coaxial to a main instrument axis (A) of the shaft (2) and about the main instrument axis ( A) is rotatably mounted, the gear device (100) - being able to be connected in the actuating unit (4) to the drive (40), the drive axis of rotation (D) of which deviates from the main axis (A) of the instrument, and - having a gear disc (104), with which the main shaft (8) can be actuated in rotation in a mounting arrangement of the transmission device (100) in the surgical instrument (1), wherein an axis of rotation (B) of the transmission disk (104) runs parallel to the main axis (A) of the instrument in the mounting arrangement, and wherein you e gear disc (104) in the assembly arrangement can be brought into operative connection with a gear ring (19) which is connected to the main shaft (8), characterized in that the gear device (100) has a cardan shaft (101) with two cardan joints (102, 103), wherein a first cardan shaft section (106) is connected via a first cardan joint (102) to an intermediate shaft section (105) which is connected to a second cardan shaft section (109) via a second cardan joint (103), and the first cardan shaft section (106) is connected to the gear disk (104) in a rotationally fixed manner with respect to the axis of rotation (B) and the second articulated shaft section (109) can be brought into operative connection with the drive (40). Transmission device (100) after claim 1 , characterized in that a position of the cardan joints (102, 103) of the articulated shaft (101) in relation to each other, in relation to the gear disc (104) and in relation to the drive (40) is adjustable. Transmission device (100) after claim 1 or 2 , characterized in that the intermediate shaft section (105), which defines a connecting axis of rotation (C), has a third articulated shaft section (107) and a fourth articulated shaft section (108), the third articulated shaft section (107) being connected via the first universal joint (102) to the is connected to the first articulated shaft section (106) and the fourth articulated shaft section (108) is connected to the second articulated shaft section (109) via the second universal joint (103), and the third articulated shaft section (107) and the fourth articulated shaft section (108) at their respective joint remote ends are connected to one another in a rotationally fixed manner in relation to the connection axis of rotation (C), the rotationally fixed connection of the third articulated shaft section (107) to the fourth articulated shaft section (108) preferably being provided by a pin connection which has a shaft journal (113a) and a shaft journal receiving space (115a) having, wherein the journal (113a) in the journal a receiving space (115a) and a length of the intermediate shaft section (105) can be adjusted by arranging the shaft journal (113a) in the shaft journal receiving space (115a) at a depth, and wherein the shaft journal (113a) is at the end of one of the two connection partners remote from the joint, which is the third Articulated shaft section (107) and the fourth articulated shaft section (108) are formed and extends along the connection axis of rotation (C), and corresponding thereto the shaft journal receiving space (115a) in the other of the two connection partners, which the third and fourth articulated shaft section (107, 108 ) are formed and extends from the distal end along the link pivot axis (C). Transmission device (100) after claim 3 , characterized in that the non-rotatable connection of the third articulated shaft section (107) to the fourth articulated shaft section (108) - is a positive connection of the shaft journal (113a) in the shaft journal receiving space (115a), the shaft journal (113a) and the shaft journal receiving space (115a) have a corresponding cross-sectional profile deviating from a circular shape, and/or - a non-positive connection by means of at least one locking pin (120a) which is located in a transverse bore (114a) which is in the connection partner, which has the shaft journal receiving space (115a), perpendicular to extending from the journal receiving space (115a), and contacting the journal (113a) received in the journal receiving space (115a). Transmission device (100) according to at least one of Claims 1 until 4 , characterized in that the non-rotatable connection of the first articulated shaft section (106) to the gear disc (104) with respect to the axis of rotation (B) is provided by a pin connection which has a gear pin (113b) and a gear pin receiving space (115b), the Gear pin (113b) is arranged in the gear pin receiving space (115b) and a distance of the first cardan joint (102) from the gear disc (104) along the axis of rotation (B) by an arrangement depth of the Gear pin (113b) can be adjusted in the gear pin receiving space (115b), and wherein the gear pin (113b) is formed on one of the two connection partners, which are the first articulated shaft section (106) and the gear disk (104) and extends along the axis of rotation (B ) extends, and corresponding thereto the gear pin receiving space (115b) is formed in the other of the two connection partners, which are the first articulated shaft section (106) and the gear disc (104) and extends along the axis of rotation (C). Transmission device (100) after claim 5 , characterized in that the non-rotatable connection of the first articulated shaft section (106) to the gear disk (104) - is a positive connection of the gear pin (113b) in the gear pin receiving space (115b), the gear pin (113b) and the gear pin receiving space (115b) being one have a corresponding cross-sectional profile deviating from a circular shape, and/or - a non-positive connection by means of at least one locking pin (120b) which is located in a transverse bore (114b) located in the connection partner, which has the gear pin receiving space (115b), perpendicular to the Gear pin receiving space (115b) extends, is arranged and accommodated in the gear pin receiving space (115b) gear pin (113b) contacts. Transmission device (100) according to at least one of Claims 1 until 6 , characterized in that the operative connection of the second articulated shaft section (109) to the drive (40) in the assembly arrangement is a non-rotatable connection of the second articulated shaft section (109) to a drive shaft (41) of the drive (40) with respect to the drive axis of rotation (D). or with a clutch disk (140) which is coupled to the drive shaft (41) of the drive (40) in a torque-proof manner, the second articulated shaft section (109) being connected to the drive shaft (41) or to the drive interface (140) in a torque-proof manner preferably by a pin connection is provided which has a drive pin (113c) and a drive pin receiving space (115c), the drive pin (113c) being arranged in the drive pin receiving space (115c) and a spacing of the second universal joint (103) from the drive shaft (41) or the Clutch disk (140) along the drive axis of rotation (D) by an arrangement depth of the drive pin (113c) in the drive pin receptacle hmeraum (115c) is adjustable, and wherein the drive pin (113c) is formed on one of the connection partners, which are the second articulated shaft section (109) and the drive shaft (41) or the second articulated shaft section (109) and the clutch disc (140) and extends along the drive axis of rotation (D), and the drive pin receiving space (115c) is formed in the other connection partner, which is the second joint shaft section (109) and the drive shaft (41) or the second joint shaft section (109) and the clutch disc (140). and extends along the drive axis of rotation (D). Transmission device (100) after claim 7 , characterized in that the non-rotatable connection of the second articulated shaft section (109) to the drive shaft (41) or to the clutch disk (140) - is a positive connection of the drive pin (113c) in the drive pin receiving space (115c), the drive pin (113c) and the drive pin receiving space (115c) has a corresponding cross-sectional profile that deviates from a circular shape, and/or - a non-positive connection by means of at least one locking pin (120c) which is in a transverse bore (114c) located in the connection partner which has the drive pin receiving space ( 115c), extending perpendicularly to the drive pin receiving space (115c), and contacting the drive pin (113c) received in the drive pin receiving space (115c). Transmission device (100) according to at least one of Claims 1 until 8th , characterized in that the gear disc (104) of the gear device (100) forms a spur gear in the assembly arrangement with the gear ring (19) which is connected to the main shaft (8), the gear disc (104) being replaced by a spur gear (104 ) and the ring gear (19) are provided by a spur ring (19) meshingly engaged with the spur gear (104). Surgical instrument (1), which has a shaft (2), an actuating unit (4) arranged at the proximal end (3) of the shaft (2) and a tool (6) arranged at the distal end (5) of the shaft (2), which can be controlled by means of a drive (40), which is assigned to the actuating unit (4), via a main shaft (8) which is mounted coaxially and rotatably about a main instrument axis (A) of the shaft (2), the surgical instrument (1 ) has a gear device which - in the actuating unit (4) is connected to the drive (40), the drive axis of rotation (D) of which deviates from the main axis (A) of the instrument, and - a gear disc (104) for rotary actuation of the main shaft (8) whose axis of rotation (B) is parallel to the main axis of the instrument (A) and which is in operative connection with a gear ring (18) which is connected to the main shaft (8), characterized in that the gear device is a gear device (100) according to at least one of Claims 1 until 9 is.

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