Orthopedic joint device

Abstract

The invention relates to an orthopedic joint device comprising: an upper part (10) and a lower part (20) which are mounted pivotably relative to one another about a common joint axis (15); and a rotary hydraulic device (30) with a hydraulic fluid, having a housing (31) in which a chamber (32) and a pivoting piston (40) which is pivotally mounted in the chamber are arranged and which divides the chamber (32) into a buckling chamber (33) and an extension chamber (34) which are hydraulically connected to each other by means of at least one channel (35), the pivoting piston (40) having a receptacle (42), wherein or on the housing (31) a sealing device (50) acting in the direction of the housing (31) is arranged, which sealing device (50) is designed to be acted upon by a hydraulic fluid in a first pivot direction on a force facing away from the housing (31) and in an opposite pivot direction on a force directed toward the housing (31).

Description

Technical field

[0001] The present invention relates to an orthopedic joint device, which includes: an upper component and a lower component, which are pivotally mounted on each other about a common joint axis; and a rotary hydraulic device having a hydraulic fluid, the rotary hydraulic device having a housing, a chamber is provided in the housing, and a pivot piston pivotally mounted in the chamber, the pivot piston divides the chamber into a flexion chamber and an extension chamber, and the two chambers are hydraulically connected to each other through at least one channel, wherein the pivot piston has a receiving portion, and a sealing device acting on the housing is arranged therein or thereon. Background art

[0002] Orthopedic joint devices are used in orthoses, exoskeletons or external prostheses to connect the upper component and the lower component in a joint manner. A joint axis is formed between the upper component and the lower component. In a single-axis joint, the axis has a fixed association with both the upper component and the lower component. In a multi-axis joint, the joint axis can vary within a pivot angle range relative to the upper component or the lower component. In order to influence the pivot movement of the upper component and the lower component, a drive device or a damper is provided on the orthopedic joint device. The damper can have different design forms and convert the kinetic energy into other forms of energy, especially heat energy. Usually, the resistance device is designed as a hydraulic damper, which can transmit high forces in a relatively small space and precisely control the resistance characteristics. The hydraulic damper, for example, has a displacement piston that is movably arranged in a cylinder and divides it into an extension chamber and a flexion chamber. When the upper component moves relative to the lower component, the piston moves in the cylinder, changing the volume of the two chambers, so that the hydraulic fluid is transported from one chamber to the other through a fluid connection. In order to influence the flow characteristics and thus the resistance characteristics, a throttle or a valve is installed in the fluid connection. The flow resistance can be adjusted through the throttle or the valve. In addition to a one-time setting, the flow cross-section can also be changed during use, for example, according to the joint angle or based on a sensor signal (processed in an electronic control device).

[0003] As an alternative to linear hydraulics (where the piston moves linearly on the piston rod), there is a so-called rotary hydraulic device, where the piston is arranged on a pivot shaft that is rigidly connected to one of the two joint components. A chamber is arranged or formed on the other joint component, and the piston pivots in the chamber. The piston also divides the chamber into an extension chamber and a flexion chamber, and there is also a fluid connection between them. Such a rotary hydraulic device is known, for example, from DE102017124337B4.

[0004] CN216478131U shows a rotary hydraulic device with a pivot piston arranged on a pivot shaft. Grooves are formed in the pivot piston and the pivot shaft, and a sealing device is arranged therein. The sealing device is designed to ensure that no fluid leaks through the gap between the housing wall and the pivot piston or the pivot shaft.

[0005] WO99 / 00075A1 relates to a computer-controlled hydraulic resistance device for a prosthesis or other device having an upper part and a lower part pivotally mounted thereon, and a rotor pivotally arranged in a chamber. The rotor has two circumferential grooves with circumferential sealing means.

[0006] In other embodiments, the required sealing between the flexion chamber and the extension chamber is achieved by the smallest possible clearance size, so that no additional sealing means are required around the rotating blades. The internal sealing effect is achieved by manufacturing the smallest possible clearance.

[0007] The presence of the clearance causes so-called clearance losses, which limits the torque that can be transmitted by the joint device. To minimize the clearance losses, such rotary hydraulic devices typically use oil filling, which has a higher viscosity compared to the oil in linear hydraulics. However, the viscosity of such hydraulic fluids varies greatly with temperature. Summary of the Invention

[0008] The object of the present invention is to provide an orthopedic joint device that can, on the one hand, transmit high torque until the joint device locks up, and on the other hand, can minimize the basic resistance level of the rotary hydraulic device.

[0009] The present invention solves the above task by an orthopedic joint device having the features of the main claim. Advantageous embodiments and improvements of the present invention are disclosed in the dependent claims, the description and the drawings.

[0010] The orthopedic joint device described includes: an upper part and a lower part, which are pivotally mounted relative to each other about a common joint axis; and a rotary hydraulic device having a hydraulic fluid, the rotary hydraulic device having a housing in which a chamber is provided and a pivot piston pivotally mounted in the chamber, the pivot piston dividing the chamber into a flexion chamber and an extension chamber, the two chambers being hydraulically interconnected by at least one passage, wherein the pivot piston has a receiving portion on or in which a sealing device acting on the housing is arranged, characterized in that the sealing device is designed to be loaded by the hydraulic fluid with a force directed away from the housing in a first pivot direction and with a force directed towards the housing in the opposite pivot direction. Preferably, the receiving portion of the sealing device is formed on the outer side of the pivot piston, where the sealing device is, for example, placed in a receiving portion formed as a groove. Alternatively, the receiving portion is formed as a pin at least partially constituting the pivot piston, and the sealing device is arranged at or on the pin. Depending on the application purpose, different requirements are imposed on the orthopedic joint device. For example, an artificial knee joint (such as a prosthetic knee joint or an orthosis knee joint) should generally have the ability to be fully locked in the flexion direction, while providing as little pivot resistance as possible during extension or straightening. The artificial knee joint should enable the possibility of quickly moving from a bent flexion position to a straightened extension position, while being able to lock the flexion as completely as possible to avoid accidental bending or collapse of the artificial knee joint. For an artificial elbow joint, easy flexion may be required while being locked in extension. For an artificial ankle joint, a high resistance to dorsiflexion and a low resistance to plantarflexion may be advantageous. Since full locking is to be achieved, it is advantageous to provide an effective sealing device between the pivot piston and the housing wall as a component to avoid leakage losses, so the sealing device abuts against the housing wall and is pre-tensioned towards the housing wall in one embodiment. Herein, the sealing device or its cross-section is designed such that, in the first pivot direction, the hydraulic fluid pressed into the gap between the pivot piston and the housing presses the sealing device away from the housing wall, thereby causing an intended leakage loss. In this way, the pivot resistance of the system in a specific direction (such as the extension direction) is minimized because, in addition to the flow through the connecting passage between the extension chamber and the flexion chamber, the hydraulic fluid can also flow through the gap, and / or the frictional force of the sealing device on the housing wall is reduced or eliminated. Conversely, in the opposite direction (such as the flexion direction), the hydraulic fluid pressure in the gap presses the sealing lip against the inner wall of the housing, thereby increasing the pressing force of the sealing device preferably elastically pre-tensioned against the housing wall. Thus, a self-reinforcing, direction-dependent sealing effect occurs, and a complete seal without leakage loss can be achieved when the hydraulic connection passage between the extension chamber and the flexion chamber is completely closed. The sealing device between the pivot piston and the housing wall is preferably provided around the entire outer circumference of the pivot piston and extends to the axially spaced side edges extending radially outwards from the pivot and the radially outer head side.

[0011] In one embodiment, the sealing device is pre-tensioned towards the housing, in particular elastically pre-tensioned, for example by the material properties of the sealing device (in particular flexible and / or elastically deformable materials), or by separate elastic elements (such as springs, elastomeric elements, etc.), so that the sealing device is pre-tensioned against the housing wall. In one embodiment, the sealing device has an interference fit and is compressed during assembly so as to closely adhere to the housing wall during use.

[0012] In one embodiment, the sealing device has at least one sealing lip, on which at least one contact area for abutting against the housing is formed, wherein the sealing lip has an inclined profile. The inclination of the sealing lip inclines from the buckling chamber towards the extension chamber, that is, it inclines relative to the pivoting direction. At the head side or the connecting edge or the radially outer edge region of the pivoting piston, the sealing lip has a profile inclined towards the radial direction. The inclination direction depends on the behavior of the sealing device required during use. In order to achieve a sealing enhancement effect of the sealing lip during the buckling movement, the sealing lip has a slope pointing towards the housing wall from the extension chamber towards the buckling chamber, so that in the unloaded state, the sealing end facing the buckling chamber is farther away from the pivoting piston than the sealing end facing the extension chamber. If it is desired to use the enhancement effect of the hydraulic fluid to press the sealing device against the housing wall with an additional pressing force during the extension movement, the inclination direction is opposite. The inclination or slope can be continuous, linear or stepped.

[0013] In an extended solution, the sealing lip has a radial section, which is connected to the sealing lip and extends inwards from the sealing lip towards the pivoting piston or the receiving part and is supported on the receiving wall or the carrier. In an embodiment where the receiving part is designed as a groove, the receiving wall is one of the groove walls. If the sealing device is arranged outside the receiving part, a carrier is provided therefor, and the sealing lip is supported on the carrier. The carrier can be formed, for example, as a covering or a cap-shaped part, which is sleeved on the core or the pivot of the pivoting piston.

[0014] In an extended solution, the sealing device has a base section, which is connected to the radial section and is supported on the receiving bottom or the carrier, or is formed as the carrier. In an embodiment where the receiving part is designed as a groove, the radial section is located at the bottom of the groove or is supported thereon; if the carrier is an additional part or a covering, the base section is fixed to the carrier or is formed as a part of the carrier.

[0015] In one embodiment, a storage space for hydraulic fluid is formed between the base section and the sealing lip. When the pivot piston moves in a certain direction, the hydraulic fluid can be pressed into this space, and in this direction, the hydraulic fluid will press the sealing lip against the housing or exert a supporting force. By collecting the hydraulic fluid in the storage space and designing the shape of the storage space, the force introduction and deformation of the sealing device when the stagnation pressure increases can be affected. For example, multiple contact areas arranged in sequence in the pivot direction can be provided, and they can move outward towards the housing wall in sequence or cascadingly, according to the pressure acting on the sealing device, so as to achieve multiple seals of the sealing device.

[0016] In particular, in order to prevent accidental buckling, the sealing lip is inclined outward or arranged to be inclined outward towards the buckling chamber to achieve buckling locking. If extension locking is required, the corresponding reverse inclination or bevel is achieved.

[0017] In one embodiment, the sealing lip is designed to have one-sided pressure enhancement and pressure weakening in the radial direction according to the pivot direction, where pressure enhancement occurs in one pivot direction and pressure weakening occurs in the opposite pivot direction, which refers to the pressing force of the hydraulic fluid on the sealing lip. The enhancement or weakening is in the direction towards the housing, so the sealing lip or the sealing device is subjected to a force that deviates from the pivot piston towards the housing wall or vice versa, deviating from the housing wall towards the pivot piston.

[0018] In one embodiment, multiple sealing lips or contact areas are arranged one after another, and they are designed to be cascade pressure-activated. The sealing effect is first enhanced at the sealing lip or the frontmost contact area in the pivot direction. As the pressure increases, the subsequent contact area or another sealing lip is pressed against the housing wall or the pressing force is enhanced. On the contrary, in the pivot direction that weakens the pressing force of the sealing lip, the frontmost sealing lip or the frontmost contact area is first moved away from the housing wall or a force deviating from the housing wall is applied, and then the contact area or the subsequent sealing lip located after the pivot direction is displaced or deformed accordingly.

[0019] In one embodiment, the receiving part of the sealing device is arranged on the side and head side of the pivot piston, and is designed as a groove, for example. Alternatively, the receiving part is formed as a pin for receiving the carrier of the sealing device.

[0020] The receiving part can also be formed in the rotating pin, on which the pivot piston is arranged or molded.

[0021] In one embodiment, the pivot piston is designed as a multi-piece type to facilitate manufacturing and assembly. At this time, the receiving part is formed between two pivot piston components.

[0022] In one embodiment, at least one form - fitting element is formed or arranged on or in the receiving part of the pivot piston, which form - fitting element interacts with a correspondingly formed form - fitting element on the sealing device in the assembled state. The form - fitting element on or in the receiving part can be, for example, a notch formed in the receiving wall or receiving bottom or on the pivot, while a projection of a corresponding shape is molded, formed or arranged on the sealing device. Conversely, the form - fitting element on the pivot piston can be designed as a projection, and the form - fitting element on the sealing device is designed as a notch of a corresponding shape. The form - fitting elements are arranged such that they engage with each other when the sealing device is assembled in or on the receiving part.

[0023] In one embodiment, the orthopedic joint device is designed as an artificial knee joint or ankle joint, in particular a prosthetic knee joint, prosthetic ankle joint, orthosis knee joint or orthosis ankle joint, or is designed as an external prosthesis or orthosis for the hip, hand or other body parts.

[0024] In the channel forming the main fluid connection between the extension chamber and the flexion chamber, at least one throttle or valve is advantageously arranged, through which the flow resistance between the extension chamber and the flexion chamber can be adjusted. The valve or throttle can be permanently set, and its setting can be adjusted according to the required resistance characteristics of the rotary hydraulic device. Alternatively, a sensor - based control method, especially microprocessor - controlled, can also be used, which collects data based on sensor values during the use and / or movement of the orthopedic joint device, and adjusts the throttle or valve based on this data through an actuator.

[0025] In one embodiment, the sealing device has a friction - reducing coating or surface treatment. This further promotes the pivoting movement in the pivoting direction in which the sealing device is moved away from the housing wall or a force is applied in the corresponding direction, and further reduces the resistance in this direction. Through the friction - reducing coating or surface treatment, easy pivoting of the orthopedic joint device can be achieved. The friction - reducing effect brought by the coating or surface treatment is compensated and over - compensated in the opposite pivoting direction by the geometry and the hydraulically enhanced sealing effect. As a surface treatment, for example, treatments that particularly consider changing the surface topography, such as RFN treatment (nanotechnology friction reduction), are especially considered. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The same reference numerals represent the same components. The illustrations are as follows:

[0027] Figure 1 : Illustration of a part of an orthosis knee joint;

[0028] Figure 2 : Detailed illustration of the pivot piston;

[0029] Figure 3: Separate illustration of the sealing device;

[0030] Figure 4 : Figure 2 Variant of

[0031] Figure 5 : Figure 4 Separate illustration of the sealing device in

[0032] Figure 6 : Figure 1 Perspective view of the variant;

[0033] Figure 7 : Separate illustration of a one-piece pivot piston;

[0034] Figure 8 : According to Figure 7 Separate illustration of the sealing device;

[0035] Figure 9 : Cross-sectional view of the sealing device;

[0036] Figure 10 : According to Figure 9 Perspective view of the sealing device;

[0037] Figure 11 : Variant of the pivot piston; and

[0038] Figure 12 : Side view of an orthopedic joint device. Detailed Description

[0039] In the Figure 12 side view, an orthopedic joint device designed as an external prosthetic knee joint 1 is shown, the upper part 10 of which has an upper connecting member 11 (designed as a pyramid adapter). A prosthetic socket for accommodating the thigh stump can be fixed on the upper connecting member 11. The upper part 10 is pivotally mounted relative to the lower part 20 about a pivot 15, and the distal end of the lower part 20 is provided with a receiving portion for the calf tube. A housing 30 is formed or arranged in the lower part 20, in which a rotary hydraulic device is accommodated. Other components of the rotary hydraulic device can be arranged in the lower part 20.

[0040] Figure 1 A part of the orthotic knee joint 1 is shown in a side view, which has a housing 30 with a chamber 32 formed therein, and a pivot piston 40 is pivotally mounted in it about a pivot 15. The orthotic knee joint 1 is designed as a single-axis knee joint, and the pivot piston 40 is rigidly connected to the upper part 10. In accordance with Figure 1In the position shown, the pivot piston 40 is at the extended end position, at which time the orthotic knee joint reaches the maximum extended state. The pivot piston 40 divides the chamber 31 into an extension chamber 34 and a flexion chamber 33. When the upper member 10 pivots relative to the lower member 20 in the flexion direction, due to the rigid connection of the pivot piston 40 to the upper member 10, the pivot piston 40 pivots counterclockwise within the chamber 32. The hydraulic fluid within the chamber 32 moves from the flexion chamber 33 through the passage 35 in the housing 30 and the throttling means (designed as the valve 61 and / or the restrictor 60) to the extension chamber 34. The valve 61 can be designed to be adjustable. The adjustment can be achieved by computer control based on sensors. Alternatively, the restrictor 60 and / or the valve 61 can be permanently set for a specific user. The restrictor 60 or the valve 61 can be manually and permanently adjusted through an external inlet. Such a joint device or joint 1 is in one embodiment part of an orthosis, and two joint devices arranged on the medial and lateral sides of the knee joint can be used in combination in the orthosis. Alternatively, only one such joint device is arranged unilaterally on the knee joint. In this case, the proximal and distal ends of the orthotic joint preferably have brace connectors to connect the joint to the rest of the orthosis. Applications at other joint sites (such as the elbow joint) are also achieved in one embodiment. Alternatively, the pivot piston device is used for a prosthetic knee joint.

[0041] In Figure 1 it, the pivot piston 40 is designed as a one-piece and has a grooved receiving portion for the sealing device 50. The sealing device 50 is placed into this groove. The sealing device 50 extends around the entire outer side surface 41 of the pivot piston 40 and has a sealing lip 51 that projects beyond the outer side surface 41 towards the housing 31. The receiving portion is filled by the sealing device 50, and the sealing device 50 is supported on the receiving walls in both pivoting directions. The support for the sealing device 50 to act in the direction towards the housing 31 is formed by the bottom of the receiving portion or the bottom of the groove.

[0042] In Figure 2 it, according to Figure 1The pivot piston 40 is shown separately. The pivot piston 40 has two pivot piston parts 46, 47 that are detachably connected. The connection can be achieved, for example, by screws that pass through holes in one pivot piston part 47 and are screwed into threads in the other pivot piston part 46. A notch serving as a form-fitting element 48 is machined in the pivot piston 41, and a corresponding form-fitting element 58 (shaped like a nose-shaped projection) can be placed therein in a form-fitting manner. The sealing device 50 is placed in the receiving portion 42 formed between the two pivot piston parts 46, 47 and is fixed in the radial direction by the form-fitting elements 48, 58. The receiving wall 43 formed by the pivot piston parts 46, 47 prevents the sealing device 50 from shifting in either pivot direction. The receiving wall 43 is connected to the receiving bottom 44, and the sealing device 50 is supported thereon on the inside. The sealing device 50 has a sealing lip 51 that projects above the outer contour or outer side surface 41 of the pivot piston 40, and its structure and function will be described later. The pivot piston 40 is rigidly mounted between two pivot pins 45 that are rotatable in the lower part 20 and are rigidly connected to an upper part 10 (not shown). Thus, when the upper part 10 pivots relative to the lower part 20, the pivot piston 40 is pivoted about the joint axis 15. The terms "upper part" and "lower part" do not imply any restrictions regarding the arrangement of the parts, especially no determination of their mutual positional relationship in the distal or proximal direction, and are only used to distinguish the parts.

[0043] In Figure 3 is shown placed Figure 2Separate illustration of the sealing device 50 in the pivot piston shown. The sealing device 50 has a substantially U-shaped profile with the connecting side located on the end face or the connecting side on the radially outer side (between two radially outwardly extending wings), and the wings are arranged on the side of the pivot piston. Shape-locking elements 58, designed as projections, are respectively formed at the ends of the free wings and are inserted into corresponding notches 48 in the pivot piston part 46. The sealing device 50 has an outer circumferential sealing lip 51 which has at least one contact area 52 that abuts against the inner wall of the housing in the assembled state. The sealing lip 51 with the contact area 52 extends in the pivot direction to a depth from the receiving wall to the free end of the sealing lip 51, wherein the sealing lip 51 is connected to a radial section 53 which extends inwards from the sealing lip 51 or the outer contour 41 of the pivot piston 40. On the end face, the radial section 53 extends radially inwards; on the side of the pivot piston, it extends axially inwards towards the pivot piston or along the receiving wall. The radial section 53 is connected to a base section 54 which is supported on the receiving bottom 44. The depth of the base section 54 can be greater than the depth of the sealing lip 51. A storage space 55 is formed between the base section 54, the radial section 53 and the sealing lip 51, and when the pivot piston 40 rotates in the corresponding direction, hydraulic fluid can be pressed from one chamber into it. The hydraulic fluid can be introduced into the storage space 55 from the side of the screwed pivot piston part 47, due to the inclined design, from the sealing lip 51 inwards towards the pivot piston 40. Due to the hydraulic fluid accumulated in the storage space 55, the material of the sealing device 50 is compressed and extruded outwards. The base section 54 is pressed against the receiving bottom 44, and the sealing lip 51 with the contact area 52 is pressed against the inner wall of the housing. Thereby, the pressing force of the sealing lip 51 and the contact area 52 relative to the inner wall of the housing is increased, achieving an improved sealing effect.

[0044] Figure 4 Shows a variant of the multi-piece pivot piston embodiment according to Figure 2 . The difference from the Figure 2 embodiment is that at the transition of the pivot piston 40 to the rotary pin 45, a groove is machined in the pivot piston 40 and the tab 59 of the sealing device 50 is inserted into it. The design of the corresponding sealing device 50 is shown in Figure 5 . The tab 59 connects the two wings of the sealing device 50 (which are located on the side of the pivot piston to achieve the sealing effect between the extension chamber and the flexion chamber). The tab 59 stabilizes the now substantially rectangular sealing device 50 and additionally prevents accidental deformation of the sealing device 50.

[0045] Figure 1 A variant of the Figure 6 embodiment is shown in Figure 6 where the pivot piston 40 has a different profile and is moreover of one-piece design.Also shown is a channel 35 in the lower part 20, which establishes a fluid connection between the extension chamber 34 and the flexion chamber 33. A device influencing the flow resistance, in particular at least one restrictor or valve, is arranged within this channel 35.

[0046] Figure 7 Shows a separate illustration of the pivot piston 40 according to Figure 6 The pivot piston 40 has a smooth outer contour. The receiving part 42 is shaped as a milled or machined groove, into which a sealing device 50, which is substantially U-shaped, is placed. The sealing lip 51 protrudes beyond the outer side surface 41 at the rear of the pivot piston 40. The front part of the pivot piston 40 has a slightly reduced contour or chamfer, so that on the side opposite the radial section, the clearance dimension between the piston and the inner wall of the housing is larger than the clearance dimension on the support side of the radial section. This makes it easier for the hydraulic fluid to be pressed into the storage space 55 and to press the sealing lip 51 outwards against the inner wall of the housing.

[0047] Figure 8 Shows the sealing device 50 placed into Figure 7 the pivot piston 40 in a bent shape, whose basic structure is the same as that of the sealing device 50 in Figure 3 and Figure 5 .

[0048] Figure 9 Shows a cross-sectional view of the sealing device 50. The back with the form-fitting element 58 and the radial section 53 is above, and the storage space 55 opens downwards. The sealing device 55 has a circumferential, outer sealing lip 51, which has a total of three contact areas 52, which are designed in a stepped manner and have sealing edges, which can abut against the inner wall of the housing (not shown), where in the initial position without pressure action, not all sealing edges have to abut. The sealing edges abutting against the inner wall of the housing is beneficial for establishing a pressing force in the storage space, but is not absolutely necessary. The sealing lip can also abut against the inner wall of the housing only after the establishment of the stagnant pressure. The base section 54 protrudes beyond the leading edge of the sealing lip 51, thus also forming a clearance in the pivoting direction through which the hydraulic fluid can enter the storage space 55.

[0049] Figure 10 Is shown in perspective view the sealing device 50 according to Figure 9 . It can be seen in both illustrations that the depth of the base section 54 is greater than that of the sealing lip 51 and protrudes beyond the leading edge of the sealing lip 51, thus forming a clearance in the pivoting direction through which the hydraulic fluid can enter the storage space 55. If according to Figure 9 and Figure 10In the illustration, when the sealing device 50 is pivoted downward in the drawing plane, the sealing lip 51 (the front contact area 52 of which may have been in contact with the inner wall of the housing) will further bend towards the inner wall of the housing, because the stagnant pressure (especially the contact area 52) generates resistance to the pivoting movement, and the flexible (especially elastic) material of the sealing lip 50 rolls outwards, thereby increasing the width of the storage space 55 at the leading edge of the sealing lip 51. At the same time, the hydraulic fluid pressed into the storage space 55 at high pressure ensures that the material of the sealing lip 50 is pressed against the housing bottom and the inner wall of the housing. Thus, the contact area 52 located behind the leading edge or the first contact area 52 abuts against the inner wall of the housing, followed by the third contact area 52 (closest to the form-fitting element 58). The contact areas 52 are respectively the edges formed on the serrated surface on the outer surface of the sealing lip 51. The inclination of the stepped wall section inclines outwards from the radial section 53. Therefore, the hydraulic fluid pressed against the sealing lip 51 from the side of the radial section 53 presses the material of the sealing device 50 against the base section 54 or the housing bottom 44. Thus, the contact area 52 is moved away from the inner wall of the housing, and the sealing lip 51 bends inwards towards the pivoting piston 40 especially in the area of the storage space 52, so that the hydraulic fluid can enter another chamber through the gap along the outside of the pivoting piston of the sealing device 50. Thereby, the resistance of the corresponding rotational movement (especially the extension movement) is reduced.

[0050] Figure 11 A variant is shown, in which the pivoting piston has a pin-shaped receiving part 42, and a carrier 70 made of flexible (especially elastic) material is inserted thereon. Then, the sealing lip 51 is arranged or molded on the outside of the carrier 70, and its contour inclines upwards from the carrier 70 towards the inner wall of the housing in the pivoting direction, thereby realizing the enhancement of the pressing force of the sealing device 50 on the inner wall of the housing depending on the pivoting direction. In one direction, the sealing lip 51 bears the acting force away from the housing (especially being lifted from the inner wall of the housing), and in the other direction, the sealing lip 51 is affected by the hydraulic fluid and possibly the deformation caused by the frictional movement on the housing, and bears an enhanced force pointing towards the housing.

[0051] The sealing device 50 and especially the sealing lip 51 can have a friction-reducing coating or surface treatment to provide a further reduced frictional resistance especially in the pivoting direction where the pressing effect is weakened.

Claims

1. An orthopedic technology joint device, comprising: An upper part (10) and a lower part (20), which are pivotally supported on one another about a common joint axis (15); And a rotary hydraulic device (30) having a hydraulic fluid, the rotary hydraulic device having a housing (31), the housing having a chamber (32) and a pivot piston (40) pivotally supported in the chamber, the pivot piston dividing the chamber (32) into a flexion chamber (33) and an extension chamber (34), the flexion chamber and the extension chamber being hydraulically interconnected by at least one channel (35), wherein the pivot piston (40) has a receiving portion (42), in or on which a sealing device (50) acting in the direction of the housing (31) is arranged, characterized in that the sealing device (50) is configured to be loaded by the hydraulic fluid with a force acting away from the housing (31) in a first pivot direction and with a force acting towards the housing (31) in the opposite pivot direction.

2. The orthopedic joint device according to claim 1, characterized in that, The sealing device (50) is preloaded towards the housing (31), in particular elastically preloaded.

3. The orthopedic joint device according to claim 1 or 2, characterized in that, The sealing device (50) has at least one sealing lip (51), on which at least one contact area (52) for abutting against the housing (31) is configured, and the sealing lip (51) has an inclined profile.

4. The orthopedic technology joint device according to claim 3, characterized in that, The sealing lip (51) is connected to a radial section (53), which extends inwards from the sealing lip (51) and is supported on a receiving wall (43) or a carrier (70).

5. The orthopedic joint device according to claim 4, characterized in that, The sealing device (50) has a base section (54), which is connected to the radial section (53) and is supported on a receiving bottom (44) or a carrier (70).

6. The orthopedic joint device according to claim 5, characterized in that, A storage space (55) for the hydraulic fluid is configured between the base section (54) and the sealing lip (51).

7. The orthopedic joint device according to any one of claims 3 to 6, characterized in that The sealing lip (51) is configured to be inclined towards the flexion chamber (33).

8. The orthopedic joint device according to any one of claims 3 to 7, characterized in that The sealing lip (51) is configured to be oriented such that the pressure increases and decreases unilaterally according to the pivot direction.

9. The orthopedic joint device according to any one of claims 3 to 8, characterized in that A plurality of sealing lips (51) or contact areas (52) are arranged one behind the other, and they are configured to be pressure-activated in a cascaded manner.

10. The orthopedic joint device according to any one of the preceding claims, characterized in that, The receiving portion (42) is configured to surround the side edges and the head side of the pivot piston (40) or is configured as a pin.

11. The orthopedic joint device according to any one of the preceding claims, characterized in that, The receiving portion (42) is configured in a rotary pin (45), on which the pivot piston (40) is arranged or molded.

12. The orthopedic technology joint device according to any one of the preceding claims, characterized in that, The pivot piston (40) is configured as a multi-piece, and the receiving portion (42) is configured between two pivot piston components (46, 47).

13. The orthopedic technology joint device according to any one of the preceding claims, characterized in that, On the pivot piston (40), in or on the receiving portion (42), at least one form-fitting element (48) is configured in a receiving wall (43) or a receiving bottom (44), and a form-fitting element (58) of a corresponding shape is configured on the sealing device (50).

14. The orthopedic joint device according to any one of the preceding claims, characterized in that, The orthopedic joint device is configured as an artificial knee joint, elbow joint or ankle joint.

15. The orthopedic technology joint device according to any one of the preceding claims, characterized in that, At least one throttle (60) or valve (61) is arranged in the channel (35).

16. The orthopedic joint device according to any one of the preceding claims, characterized in that, The sealing device (50) has a friction-reducing coating or a friction-reducing surface treatment.

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