DE102021119532B4 - Surgical instrument and gear device therefor - Google Patents

Abstract

Gear device (100) for a surgical instrument (1), which has a shaft (2), an actuating unit (4) arranged at the proximal end (3) of the shaft (2) and an actuating unit (4) arranged at the distal end (5) of the shaft (2). Tool (6) which can be controlled by means of a drive (40) which is assigned to the actuation unit (4) via a main shaft (8) which is coaxial with a main instrument axis (A) of the shaft (2) and around the main instrument axis ( A) is rotatably mounted, the gear device (100) - in the actuating unit (4) being connectable to the drive (40), the drive axis of rotation (D) of which deviates from the main instrument axis (A), and - having a gear disk (104), with which the main shaft (8) can be rotatably actuated in a mounting arrangement of the gear device (100) in the surgical instrument (1), an axis of rotation (B) of the gear disk (104) in the mounting arrangement running parallel to the main axis of the instrument (A), and where the gear disk (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 via a second cardan joint (103) to a second cardan shaft section (109), and wherein the first cardan shaft section (106 ) is connected to the gear pulley (104) in a rotationally fixed manner with respect to the axis of rotation (B) and the second cardan shaft section (109) can be brought into operative connection with the drive (40).

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 a hollow main shaft is arranged which extends coaxially to the longitudinal axis of the shaft, is rotatable about the longitudinal axis of the shaft and extends beyond the proximal end of the shaft into the actuation 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., can also be axially displaceable within the hollow main shaft. B. for opening and closing, which also extends into the actuation unit on the proximal side. In order to further angle the distal tool tip relative to the longitudinal axis of the shaft, a joint mechanism made up of pivoting members arranged at the distal end of the shaft can be actuated, similar to a spinal column, by steering wires arranged all around. For this purpose, the steering wires in the actuation unit can be attached to a swash plate mounted on the main shaft, via which spatial alignment the pivoting of the tool tip is controlled.

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

Also US 10 105 128 B2 describes the possibility of a rotational coupling of an instrument shaft with the handle, without going into detail, but rather focuses on the alignment mechanics 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 fastening section for operative coupling with the drives of the robot, which is equipped with a gear transmission for rotational 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 is in meshing engagement with a second gear wheel, the axis of rotation of which is parallel to the shaft axis. The second gear wheel in turn engages with a ring gear section of the shaft arrangement. The first transmission gear is in engagement with a drive wheel that is coupled to a drive motor of the robot via a drive element. 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, 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 rotating 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 small manufacturing and assembly tolerances given the relatively complex geometry of the bevel gears, which is associated with high costs.

Further is over DE 10 2013 225 117 A1 a drive arrangement for an endoscopic shaft instrument is known, in which a housing shaft in the instrument housing is aligned obliquely to a drive shaft, to which the housing shaft is connected via traction means for controlling the distal instrument tip.

CN 2 13 499 189 U discloses an endless mechanism for a medical instrument coupled to a surgical tool and a kinematic chain having at least two cardan joints with axes of rotation perpendicular to one another.

US 2015 /0 083 777 A1 relates to a handle for a surgical stapler having a power transmission mechanism for transmitting the linear motion of a linear motor to an end effector via a universal joint arrangement, a coupling and a flexible shaft.

Based on this prior art, it is the object of the present invention to provide an improved transmission for a surgical instrument for transmitting the rotational movement of a drive in a rotational movement of a main shaft mounted in a shaft.

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

Preferred embodiments are set out in the subclaims.

The further task of providing a correspondingly improved surgical instrument is achieved by the surgical instrument with the features of independent claim 10.

The gear device according to the invention is designed for a surgical instrument which has a shaft, an actuation 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 actuation unit, via a main shaft which is mounted coaxially to a main instrument axis A, which is defined by the shaft, and rotatable about the main instrument axis A. The main shaft is rotatably arranged 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 runs perpendicular to the main instrument axis A. Furthermore, the gear device has a gear disk with which the main shaft can be rotatably 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 that 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 cardan shaft section is connected to the gear pulley in a rotationally fixed manner with respect to the axis of rotation B, while the second cardan 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 transmission between the drive and the main shaft as two spatially separate components whose axes of rotation are not aligned. The cardan shaft of the gear device transmits the driving force or rotational movement of the drive about the drive axis D, which is not in the main instrument axis A, to the gear pulley, the axis B of which is parallel to the main instrument axis A. This axial distance is bridged by the active connection between the gear disk and the gear ring. Due to its simple construction, the transmission device according to the invention is cheaper to manufacture and purchase than a bevel gear pair. Furthermore, by varying the length of the joint sections and the bending angle of the cardan joints, the transmission device according to the invention enables an almost arbitrary orientation of the drive axis of rotation D in relation to the main instrument axis A and thus an almost arbitrary arrangement of the drive motor, which is an optimal arrangement in relation to the available Installation 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, when the cardan joints are angled, forms an angle with the axis of rotation B of the transmission pulley and with the drive axis of rotation D. In order to minimize unevenness in the rotation transmission of 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, for larger flexion angles, both flexion angles can be chosen to be the same size in order to achieve the most uniform possible power transmission. In addition, in order 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 gear pulley and with the axis of rotation D of the drive. If the deflection angles are the same size and bend in opposite directions, the axis of rotation B of the gear disk (and thus also the main axis of the instrument A) and the drive axis of rotation D run parallel. If both bending angles bend in the same direction, for example by 45° each, the bending angles add up to the angle between the axis of rotation B of the gear pulley (and thus also the main axis of the instrument A) and the drive axis of rotation D, so that for the example mentioned two bending angles are 45 ° the axis of rotation B of the gear disk (and thus also the main axis of the instrument A) is vertical, i.e. H. runs perpendicular to the drive axis of rotation D.

In a further, preferred embodiment of the transmission device according to the invention, it is provided that a position of the universal joints of the cardan shaft is adjustable in relation to one another, in relation to the transmission pulley and to the drive. In this way, tolerance compensation can be achieved gen, so that the gear device provides a play-free connection between the gear pulley and a drive shaft of the drive. For this purpose, the two cardan joints can be mounted so that they can move relative to one another in order to compensate for possible angular 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 cardan shaft section and the fourth cardan shaft section are connected to one another in a rotationally fixed manner with respect to the connecting axis of rotation C at their respective ends remote from the joint. Preferably, the rotationally fixed connection of the third cardan shaft section to the fourth cardan shaft section can be provided by a pin connection which has a shaft journal which is arranged in the shaft journal receiving space. For this purpose, the shaft journal, which extends along the connection axis of rotation C, is formed at the end remote from the joint of one of the two connection partners, which consist of the third and fourth cardan shaft sections. At the end remote from the joint of the other of the two connection partners, which are the third and fourth cardan shaft sections, a shaft journal receiving space is formed, which also extends along the connection axis of rotation C. This means that the shaft journal receiving space in the third cardan shaft section is designed to extend from the end remote from the joint when the shaft journal is at the remote end of the fourth cardan shaft section, and vice versa, that the shaft journal receiving space in the fourth cardan shaft section is designed to extend from the end remote from the joint , if the shaft journal is formed at the end of the third drive shaft section remote from the joint. A length of the intermediate shaft section can be adjusted by means of 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 rotation-proof connection of the third cardan shaft section with the fourth cardan shaft section, which together form the intermediate shaft section, can be realized by positive locking, frictional locking or a combination of positive and non-positive locking between the pin and the pin receiving space. In one embodiment of the transmission device according to the invention, the rotationally fixed 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, the locking pin being arranged in a transverse bore which is in the connection partner which has the shaft journal receiving space , extends perpendicular to the shaft journal receiving space. The force or frictional connection is established by the locking pin vertically contacting the shaft journal accommodated in the shaft journal receiving space and generating a normal force that determines the friction force. Alternatively, if the transverse hole crosses 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 the received pin makes contact in order to act diametrically on the pin.

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

The rotation-proof connection of the first cardan shaft section to the gear pulley can also be achieved by positive locking, frictional locking or both. For a positive 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 pulley 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 which is located in the connection partner which contains the gear pin receiving space has, extends perpendicular to the gear pin receiving space, so that the locking pin contacts the gear pin received in the gear pin receiving space perpendicularly and generates a normal force that determines the friction force. Alternatively, if the transverse hole crosses 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 the received pin makes contact in order 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 cardan shaft section to the drive in the assembly arrangement is also a connection which is rotationally fixed with respect to the drive axis of rotation, the second cardan shaft section being rotationally fixed in the assembly arrangement with a drive shaft of the drive or with a clutch disk is connected, which is designed for rotationally fixed coupling to the drive shaft of the drive. The non-rotatable connection of the second cardan shaft section with the drive shaft or with 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 of the second cardan joint from the drive shaft or the clutch disk 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 an arrangement depth of the drive pin in the drive pin receiving space. The drive pin is formed on one of the connecting partners, which here are the second cardan shaft section and the drive shaft or the second cardan 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 other connection partner, i.e. 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 disk when the drive pin is at the end of the second drive shaft section remote from the joint, and vice versa, the drive pin receiving space is designed in the second drive shaft section to extend from the end remote from the joint when the drive pin is on the drive shaft or . the clutch disc is formed.

The rotationally fixed connection of the second drive shaft section with the drive shaft or the clutch disk 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 distance of the second cardan joint set by the arrangement depth from the drive, be a non-positive connection by means of a locking pin which is arranged in a transverse bore which extends perpendicular to the drive pin receiving space in the connection partner which has the drive pin receiving space. By contacting the locking pin with the drive pin accommodated in the drive pin receiving space, a normal force that determines the frictional force is generated. Alternatively, if the transverse hole crosses 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 the received pin makes contact in order to act diametrically on the pin.

In a further embodiment of a gear device according to the invention, the gear disk of the gear device in the assembly arrangement with the gear ring which is connected to the main shaft forms a spur gear, the gear disk being connected by a gear spur gear and the gear ring by a spur gear ring which is in meshing engagement with the gear spur gear , to be provided. Preferably, the gear spur gear and spur gear ring can be straight-toothed, since spur gearing is easier to manufacture compared to helical gearing, has less friction during operation, and enables less complex storage since no axial forces occur. However, helical or herringbone teeth are not excluded. Furthermore, in a less preferred embodiment, it is conceivable that the gear pulley in the mounting arrangement with the gear ring can form a traction drive, the operative connection between the gear pulley and the gear ring being provided by a traction means such as a chain, a rope or belt.

A further object according to the invention is a surgical instrument which, in a first embodiment, has a shaft, an actuation 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 actuation unit, via a main shaft which is mounted coaxially to a main instrument axis A, which is defined by the shaft, and rotatable about the main instrument axis A. Preferably, the shaft may be a hollow shaft so that the main shaft is rotatably disposed within the hollow shaft. The surgical instrument has a gear device in an embodiment according to the invention, wherein the gear device in the actuation unit is connected to the drive, the drive axis of rotation D of which deviates from the main instrument axis A, for example runs perpendicular thereto. For rotary 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 disk running parallel to the main axis A of the instrument. 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, which has the transmission disk at one end and a connection point to the drive 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 clearer and better understood from 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 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 gear 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 drive shaft 4 in the two setting variants a) and b),
• 6 a side section view through the drive shaft 5 in the two setting variants a) and b) along the respective cutting line AA,
• 7 a schematic side sectional view of a gear 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 gear device according to the invention for a surgical instrument.

1 shows schematically a surgical instrument 1 according to the invention with a hollow shaft 2, which defines the main axis A of the instrument, a handle or actuating unit 4 arranged at the proximal end 3 of the shaft 2, shown only schematically, and with a tool 6 arranged at the distal end 5 of the shaft 2 , which is designed here as a gripping tool with two jaws. The distal-side tool 6 can be actuated via various actuation mechanisms in the proximal-side actuation unit 4, 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 shaft 2 is a main shaft 8 which extends coaxially to the longitudinal axis A of the shaft 2 and is rotatable about the longitudinal axis A of the shaft and extends beyond the proximal end 3 of the shaft 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 driven by a motor. By rotating the main shaft 8, a corresponding rotation of the tool 6 is activated.

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 from 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 through Axial displacement of the actuating element 9 can be formed in the hollow main shaft 8.

A further, also motor-driven actuation mechanism can be used 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 may be formed on the distal tip of the instrument. For this purpose, steering wires 12 can be used, which extend through the hollow shaft 2, exit 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 swashplate 17 required to pivot the tool 6 is reduced. The serrated washer 18 arranged distally to the swashplate 17 ensures that the steering wires 12 run parallel to one another and to the longitudinal axis A of the swashplate 17, thereby simplifying assembly and production. A variant, not shown, dispenses with the serrated washer, so that the steering wires 12 run directly to the swashplate, the radial distance from the longitudinal axis A also being increased, but the steering wires hit the swashplate 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 gear 10, which is not described in detail here, and in 1 like the transmission device 100 according to the invention is only indicated schematically. Also that in 2 The exemplary surgical instrument 1 shown has, at the distal end 5 of the shaft 2, which defines the instrument's main axis A, a tool 6 made of two jaw parts which can be pivoted via a joint mechanism 7. The actuation unit 4, which is also 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 gear 10 comprises two drive wheels 13 which are arranged offset by 180° from one another 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 in engagement via its spur gear with a 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 wheel offset by 90° (not in.) stand above the respective bevel gear rim 2 and 3 can be seen) in engagement, which is arranged on a common axis with the bevel gear 11, which closes the toothed ring around the swash plate 17. The steering bevel wheel is coupled to the swash plate 17 via a steering ring (not seen) in order to transmit the movements of the drive wheels 13 via the steering bevel wheel and the steering ring to the swash plate 17 for their spatial alignment. The steering ring is therefore rotatably mounted with respect to the bevel gear 11 to allow rotation of the steering ring relative to the bevel gear 11 when the steering ring is moved by the steering bevel gear for spatial alignment of the swash plate 17 and a corresponding actuation of the steering wires 12. In order to also allow rotation about the longitudinal axis A of the swashplate 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 swashplate 17 is rotatably mounted in the steering ring.

Unlike 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 actuation 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 on the exemplary drive of the swash plate gear by means of spur teeth of the drive wheels 13 in 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 the one 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 gear 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 tip of the instrument . However, a preferred embodiment of a surgical instrument 1 according to the invention has not only a gear device 100 according to the invention, but also an actuation mechanism, for example a swash plate gear 10, for controlling a joint mechanism 7 for pivoting the tool 6 on the tip of the instrument. As a result, an angular movement of the tool 6, controlled by an actuation 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 transmission device 100 according to the invention. In the case of a swash plate gear 10, the swash plate 17 can be rotationally coupled to the main shaft 8.

A transmission device 100 according to the invention, as exemplified in 2 and 3 is shown in a state installed in the handle 4 of a surgical instrument 1, has a here as Spur gear formed gear disk 104, 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, which is designed as a spur gear ring and is connected in a rotationally fixed manner 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 correspondingly positioned bearing housings 131 on a housing component 30 for rotatably supporting the main shaft 8 with the gear ring 19 and the gear disk 104.

According to the invention, the gear pulley 104 is coupled in a rotationally fixed manner to a cardan shaft 101 with two cardan joints 102, 103, which in an exemplary embodiment in 4 until 6 is shown in detail. The drive shaft 101 protrudes from the other end 2 and 3 with a clutch disk 140 in connection with which the gear device 100 in the handle 4 of the surgical instrument 1 can be connected to a drive 40 (not shown), which is shown in dashed lines in the schematic representations of a gear device 100 in 7 and 8th is indicated. By using the cardan shaft 101 with the two cardan joints 102, 103, the drive axis of rotation D can deviate from the main instrument axis A and, for example, as in 2 and 3 perpendicular, ie at right angles to the instrument's main axis A. The cardan shaft 101 consists of a first cardan shaft section 106 connected to the gear pulley 104, which is coupled to an intermediate shaft section 105 via the first cardan joint 102. The intermediate shaft section 105 in turn is coupled via the second cardan joint 103 to a second cardan shaft section 109, which is connected, for example, via a clutch disk 140 to a drive motor 40 (cf. 7 and 8th ) can be brought into active connection. Each cardan joint 102, 103 has a central cross piece 110 with two axle elements 111, 112 crossed at right angles, the ends of each axle element 111, 112 being received in bores (not designated) which are at a respective fork end 116, 117, 118, 119 formed joint ends 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 holes at the fork end 106 of the first cardan shaft section 106 and the axle element 112 perpendicular thereto is received in the holes at the fork end 117 of the third cardan shaft section 107. In the second cardan joint 103, this is Axle element 111 is received in the holes at the fork end 119 of the second cardan shaft section 109 and the axle element 112 perpendicular to it is accommodated in the holes at the fork end 118 of the fourth cardan shaft section 108.

4 until 6 shows the structure of the cardan 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 is adjustable, so that tolerance compensation can take place in order to provide a play-free connection between the transmission pulley 104 and the drive 40. For this purpose, the intermediate shaft section 105 consists of a third cardan shaft section 107 and a fourth cardan shaft section 108, which are displaceable 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 via a pin connection Similar to a telescopic shaft, they are coupled together in a rotationally fixed manner.

The rotationally fixed pin connection of the third cardan shaft section 107 with the fourth cardan 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 cardan 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 cardan shaft section 108 remote from the joint, ie at the end facing away from the second cardan joint 103 or the fork end 118, and extends axially along the connecting 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 remote from the joint, ie from the end facing away from the first cardan joint 102 or the fork end 117, through the third cardan shaft section 107 in shown example up to the fork end 117. For rotation-proof coupling, the shaft journal 113a and the shaft journal receiving space 115a have one of the A corresponding cross-sectional profile deviating from a circular shape, which is indicated by the dashed lines on the shaft journal 113a in 4a and the shaft journal receiving space 115a in 6a - here should be a hexagonal profile. This is in 5b for the drive pin receiving space 115c in the second cardan shaft section 109 can be seen, which is provided to form 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 rotationally fixed connection and to adjust the distance of the second universal joint 103 from the drive 40. Here, the drive pin receiving space 115c extends axially along the drive axis of rotation D from the end of the second cardan shaft section 109 remote from the joint, that is, from the end facing away from the second cardan joint 103 or the fork end 119, through the second cardan shaft section 109 in the example shown to the fork end 119.

In an analogous manner, the rotationally fixed connection of the first cardan shaft section 106 to the gear pulley 104 can also be established and the distance of the first cardan joint 102 from the gear pulley 104 can be adjusted by a corresponding pin connection by a gear pin 113b arranged in a rotationally fixed manner on the gear pulley 104 (cf. 7 ) is arranged in a gear pin receiving space 115b, which is formed in the first cardan shaft section 106. For this purpose, the gear pin receiving space 115b extends axially along the axis of rotation B from the end of the first cardan 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 cardan shaft section 106 in the example of 4 until 6 to the end of the fork 116. In the example of 7 the gear disk 104 has an axle stub on the side facing away from the gear pin 113b, which can be rotated by means of a bearing 130 in a bearing housing 131 (cf. 2 , 3 ) is stored. The rotation-proof connection of the second cardan shaft section 109 to the drive 40 can also be designed as a pin connection for adjusting the distance of the second universal joint 103 from the drive 40. The coupling of the second cardan shaft section 109 to the drive 40 can take place directly on a drive shaft 41 of the drive 40, or as in 7 indicated, via a clutch disk 140, which can be connected to the drive shaft 41 in a rotationally fixed 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 coupling elements which can be brought into engagement with corresponding coupling 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 not shown from the drive shaft 41), is accommodated in the drive pin receiving space 115c formed corresponding to the drive pin 113c along the drive axis of rotation D in the arrangement depth desired for play adjustment. In the example of 4 until 6 The drive pin receiving space 115c extends from the end of the second cardan shaft section 109 remote from the joint through the second cardan shaft section 109 to the fork end 119.

Different than in 4 until 6 shown, each pin connection consisting of pin and pin receiving space can also be formed independently of one another in the opposite manner on the respective cardan shaft sections 106, 107, 108, 109 or the gear pulley 104 and the respective drive component 41, 140. For example, in 7 the shaft journal 113a is formed on the third propeller shaft section 107 and the shaft journal receiving space 115a is formed in the fourth propeller shaft section 108. Furthermore, it is not mandatory that a pin receiving space extends completely through the respective cardan shaft section to the fork end and opens there, so that the cardan shaft section is designed as a hollow shaft. A pin receiving space can also end within a cardan shaft section and provide a stop for the pin. The pin and pin receiving space can also have a cross-sectional shape that deviates from the hexagonal profile shown, which deviates from the circular shape, in order to provide a positive connection for a rotation-proof connection. The term pin connection should in no way be understood as restricting the shape or length of the pin or pin receiving space, but rather simply refers to two shaft sections that can be connected in a rotationally fixed manner in a way that allows a variation in the length of the connected shaft sections.

In order to fix the pin connection of the two cardan shaft sections 107, 108 of the intermediate shaft section 105 in the desired length or the length required to compensate for tolerances for freedom from play, the connection partner with the pin receiving space, which is in 4 until 6 the third cardan shaft section 107 and in 7 the fourth cardan shaft section 108 has a transverse bore 114a which extends perpendicular to the shaft journal receiving space 115a. The transverse bore 114a can be as in the example of 4 until 6 be a through hole so that, as in 4b , 5b can be seen, a locking pin 120a can be inserted diametrically from each side, which generates a normal force in the shaft journal receiving space 115a Shaft journal 113a contacted. The resulting force or frictional connection 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 to the shaft journal receiving space 115a, so that a single locking pin 120a is used, which contacts the shaft journal 113a accommodated in the shaft journal receiving space 115a while generating a normal force. To avoid imbalance during rotation, the symmetrical version can be equipped with two diametrical locking pins 4 until 6 be preferred.

In an analogous manner, the pin connections of the cardan shaft 101 with the gear pulley 104 and the corresponding drive component 41, 140 can optionally be secured by means of locking pins 120b, 120c, as shown in 7 can be seen in order to fix the arrangement depth of the respective 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 pulley 104 can be adjusted. Different than in 7 shown, two diametrically arranged locking pins can also be used to secure the respective pin connection. This optional securing of the pin connections of the cardan shaft 101 with the gear pulley 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 for tolerance compensation, as in the example of the cardan shaft 101 4 until 6 shows that also in the in 2 and 3 Surgical instrument 1 shown can be seen in the installed state. This cardan shaft 101 has no transverse bores to the respective pin receiving space 115b, 115c in the first and second cardan shaft sections 106, 109 and therefore no locking 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 pulley 104 and drive 40, not only tolerance compensation can 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 in 2 and 3 ) a gear 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 connecting axis of rotation C lies in a plane with the drive axis of rotation D and the axis of rotation B, which is parallel to the main axis of the instrument A. Such a configuration of the cardan shaft 101, ie with equal deflection angles and all three axes B, C, D in one plane, can be preferred. as this minimizes unevenness in the rotation 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 show further configurations of a transmission device 100 according to the invention, which provide alternative arrangement options for the drive 40, but may be associated with certain non-uniformity in the rotation transmission, especially 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 cardan joint 103 deviates from the deflection angle α 'between the connection axis of rotation C and the axis of rotation B on the first cardan joint 102, the deflection angle α on the second cardan joint 103 being larger in the example shown is as the deflection angle α 'at the first cardan joint 102. And in 8c Not only do the deflection angle α' on the first cardan joint 102 differ from the (not designated) deflection angle on the second cardan joint 103 (which is spanned between the connecting axis of rotation C and the axis of rotation D, which runs perpendicular to the plane of the drawing), but also the three Rotary axes B, C and D are not in a common plane, since the drive rotary axis D runs perpendicular to the plane defined by the connecting rotary axis C and rotary axis B.

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

Claims (10)

Gear device (100) for a surgical instrument (1), which has a shaft (2), an actuation unit (4) arranged at the proximal end (3) of the shaft (2) and an actuation unit (4) at the distal Has a tool (6) arranged at the end (5) of the shaft (2), which can be controlled by means of a drive (40) which is assigned to the actuation unit (4) via a main shaft (8) which is coaxial with a main instrument axis (A). of the shaft (2) and is rotatably mounted about the main axis of the instrument (A), the gear device (100) - in the actuating unit (4) being connectable to the drive (40), the drive axis of rotation (D) of which deviates from the main axis of the instrument (A). , and - has a gear pulley (104) with which the main shaft (8) can be rotatably actuated in a mounting arrangement of the gear device (100) in the surgical instrument (1), an axis of rotation (B) of the gear pulley (104) being in the mounting arrangement runs parallel to the main axis of the instrument (A), and wherein 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), characterized in that the gear 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) to a second cardan shaft section ( 109) is connected, and wherein the first cardan shaft section (106) is connected to the gear pulley (104) in a rotationally fixed manner with respect to the axis of rotation (B) and the second cardan shaft section (109) can be brought into operative connection with the drive (40). Gear device (100). Claim 1 , characterized in that a position of the cardan joints (102, 103) of the cardan shaft (101) is adjustable in relation to each other, in relation to the gear pulley (104) and in relation to the drive (40). Gear device (100). Claim 1 or 2 , characterized in that the intermediate shaft section (105), which defines a connecting axis of rotation (C), has a third cardan shaft section (107) and a fourth cardan shaft section (108), the third cardan shaft section (107) being connected to the first universal joint (102). first cardan shaft section (106) is connected and the fourth cardan shaft section (108) is connected to the second cardan shaft section (109) via the second cardan joint (103), and wherein the third cardan shaft section (107) and the fourth cardan shaft section (108) are at their respective points remote from the joint Ends are connected to one another in a rotationally fixed manner with respect to the connecting axis of rotation (C), the rotationally fixed connection of the third cardan shaft section (107) to the fourth cardan shaft section (108) being preferably provided by a pin connection which has a shaft journal (113a) and a shaft journal receiving space (115a). has, wherein the shaft journal (113a) is arranged in the shaft journal receiving space (115a) and a length of the intermediate shaft section (105) is adjustable by an arrangement depth of the shaft journal (113a) in the shaft journal receiving space (115a), and wherein the shaft journal (113a) on the the end of one of the two connection partners, which are the third cardan shaft section (107) and the fourth cardan shaft section (108), which is remote from the joint, is formed and extends along the connection axis of rotation (C), and correspondingly the shaft journal receiving space (115a) in the other of the two connection partners, which are the third and fourth cardan shaft sections (107, 108), and extends from the end remote from the joint along the connecting axis of rotation (C). Gear device (100). Claim 3 , characterized in that the non-rotatable connection of the third cardan shaft section (107) to the fourth cardan 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 that deviates from a circular shape, and / or - a non-positive connection by means of at least one locking pin (120a) which is perpendicular to a transverse bore (114a) which is in the connection partner which has the shaft journal receiving space (115a). the shaft journal receiving space (115a), is arranged and contacts the shaft journal (113a) received in the shaft journal receiving space (115a). Gear device (100) according to at least one of Claims 1 until 4 , characterized in that the rotationally fixed connection of the first cardan shaft section (106) to the gear pulley (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 disk (104) along the axis of rotation (B) can be adjusted by an arrangement depth of the gear pin (113b) in the gear pin receiving space (115b), and wherein the gear pin (113b) is formed on one of the two connecting partners, which are the first cardan shaft section (106) and the gear pulley (104), and extends along the axis of rotation (B), and correspondingly the gear pin receiving space (115b) in the other of the two connection partners, which are the first cardan shaft section (106) and the gear pulley (104), and extends along the axis of rotation (C). Gear device (100). Claim 5 , characterized in that the non-rotatable connection of the first cardan shaft section (106) with the gear pulley (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). have 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 (120b), which is in a transverse bore (114b), which is in the connection partner that has the gear pin receiving space (115b), perpendicular to the Gear pin receiving space (115b), is arranged and contacts the gear pin (113b) received in the gear pin receiving space (115b). Gear device (100) according to at least one of Claims 1 until 6 , characterized in that the operative connection of the second cardan shaft section (109) with the drive (40) in the assembly arrangement is a connection of the second cardan shaft section (109) with a drive shaft (41) of the drive (40) that is rotationally fixed with respect to the drive axis of rotation (D). or with a clutch disk (140) which is coupled in a rotationally fixed manner to the drive shaft (41) of the drive (40), wherein the rotationally fixed connection of the second cardan shaft section (109) to the drive shaft (41) or to the drive interface (140) is preferably carried out 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 distance of the second universal joint (103) from the drive shaft (41) or the Clutch disc (140) can be adjusted along the drive axis of rotation (D) by an arrangement depth of the drive pin (113c) in the drive pin receiving space (115c), and wherein the drive pin (113c) is on one of the connection partners, which is the second cardan shaft section (109) and the drive shaft ( 41) or the second cardan shaft section (109) and the clutch disc (140), is formed and extends along the drive axis of rotation (D), and the drive pin receiving space (115c) in the other connection partner, which is the second cardan shaft section (109) and the drive shaft (41) or the second cardan shaft section (109) and the clutch disk (140) are formed and extends along the drive axis of rotation (D). Gear device (100). Claim 7 , characterized in that the non-rotatable connection of the second cardan shaft section (109) with the drive shaft (41) or with 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 - is a non-positive connection by means of at least one locking pin (120c) which is in a transverse bore (114c) which is in the connection partner that the drive pin receiving space ( 115c), extends perpendicular to the drive pin receiving space (115c), is arranged and contacts the drive pin (113c) received in the drive pin receiving space (115c). Gear device (100) according to at least one of Claims 1 until 8th , characterized in that the gear disk (104) of the gear device (100) in the assembly arrangement with the gear ring (19), which is connected to the main shaft (8), forms a spur gear, the gear disk (104) being connected by a gear spur gear (104 ) and the gear ring (19) are provided by a spur gear ring (19), which is in meshing engagement with the gear spur gear (104). Surgical instrument (1) which has a shaft (2), an actuation 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 actuation 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 of the instrument (A), and - for the rotational actuation of the main shaft (8) a gear pulley (104) whose axis of rotation (B) is parallel to the main axis of the instrument (A) is 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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