Coupling device, valve system, and method for assembling a coupling device or valve system - Patents.com

Abstract

A coupling device (1) for connecting a drive shaft (31) of an actuator (3) to a driven shaft (51) of an exhaust gas valve (5), said coupling device (1) comprising: a torsionally rigid retaining part (2) defining a rotation axis (A) and having an axially extending slot (25), a connecting rod (45) received in the slot (25) for translational movement relative to said retaining part (2) in the direction of said rotation axis (A), and a resilient element (4) biasing said connecting rod (45) in the direction of said rotation axis (A) and having a mounting section (42) fixed to said retaining part (2), said retaining part (2) and said connecting rod (45) being non-rotatably connected.

Description

[Technical Field]

[0001] The present invention relates to a coupling device for connecting a drive shaft of an actuator to a driven shaft of an exhaust gas valve. The present invention also relates to a valve system comprising an actuator having a drive shaft, an exhaust gas valve having a driven shaft, and a coupling device. Furthermore, the present invention relates to a method for assembling the coupling device and a method for assembling the valve system. [Background technology]

[0002] Exhaust line valves are typically provided with coupling devices for connecting and operating actuators. While the driven shaft of an exhaust gas valve could theoretically be directly coupled to the drive shaft of an actuator, such as an electric motor, coupling devices are typically employed as intermediate components connecting the driven and drive shafts. The coupling device serves the overall purpose of compensating for manufacturing and thermal expansion tolerances. Manufacturing tolerances can cause axial, radial, and / or angular misalignment between the valve actuator drive shaft and the fresh gas valve driven shaft. Furthermore, because exhaust gas valve members typically experience temperatures of several hundred degrees, while valve actuators require ambient temperatures well below 100°C for proper long-term operation, the driven shaft is subject to significant thermal stresses due to temperature gradients.

[0003] Exhaust systems often include exhaust valves to improve performance, improving acoustic emissions and engine power. Many systems only have two settings, depending on the closed or fully open position of the valve flap. Closed valves often result in a low volume, while open valves result in a higher volume. Many car enthusiasts prefer a higher volume. However, exhaust valve systems must comply with increasingly stringent approval regulations. To optimize performance and ensure compliance, exhaust valve systems must be precisely controllable to meet both desired acoustic emission and engine performance standards.

[0004] US 10,060,360 B2 proposes the use of a coupling device including an elastic member that is axially compressed between the driven member and the driven member. The elastic member rotates the driven member by employing a torsion spring. The drive member and the driven member are connected solely through an elastic member that is axially and circumferentially expandable. When torque is applied from the drive member toward the driven member beyond the resistance of the elastic member, the drive tab of the drive member can directly engage a first edge or a second edge of the driven member. Thus, the drive member and its correspondingly attached drive and driven shafts can rotate relative to each other due to angular play between the drive tab and the opposing ends of the raised edge. This play prevents the valve member or flap from being accurately positioned at a specific desired position during operation. Furthermore, an unavoidable crashing noise occurs each time the drive shaft reverses direction of movement, which can cause a rattle noise.

[0005] EP 2180167 B1 proposes a coupling device with a resilient spring that directly connects the drive shaft to the driven shaft. However, it has been shown to operate reliably, especially under high thermal loads, because the structural integrity of the spring can be compromised, leading to uncertain valve positioning. Thermal stresses can also cause the torsion spring to fail due to overheating if the allowable axial load is exceeded. Furthermore, because the proposed valve using the coupling device is designed to bias the valve flap in the closed position against the valve seat, the valve flap can be damaged by repeated use due to the biasing force acting around the valve flap, the closing force, and thermal stress. Particularly in high-performance exhaust systems subject to sudden pulses of exhaust gases from the cylinders of high-performance internal combustion engines, the pulses impact the valve member, causing the resilient force of the spring connecting the drive shaft to the driven shaft to cause the valve member to rattle, or, in the worst case, to resonate with the exhaust gas pulses.

[0006] Another valve coupling device is proposed in DE102019120959A1. The coupling device is proposed as a bushing cooperating with a coil spring having straight sections at opposing ends. The straight spring sections engage corresponding recesses in the bushing, allowing the spring rotational and translational freedom relative to the bushing. DE102019120959A1 aims to avoid rattle noise when the valve flap changes direction of movement by biasing the spring, but rattle noise still occurs when the movement or position changes suddenly. The valve driver design of DE102019120959A1 is very bulky and too large for some exhaust system design configurations. Due to its bulk, the valve coupling device can cause premature failure of the valve driver due to the large mass of the valve coupling device and because too much heat is transferred from the valve flap to the drive actuator during prolonged operation. Summary of the Invention

[0007] The object of the present invention is to overcome the drawbacks of the prior art and to provide a valve system and a coupling device therefor that have a high reliability, in particular with regard to space requirements, resistance to thermal loads, improved positioning, and reduced unwanted noise effects.

[0008] This object is solved by the subject matter of the independent claims.

[0009] Thus, a coupling device is provided for connecting a drive shaft of an actuator to a driven shaft of an exhaust gas valve. The actuator may comprise an electric motor, such as a stepper motor, a servo motor, a brushed DC motor, an electrically excited DC motor, a permanent magnet DC motor, a brushless DC motor, a switched reluctance motor, a torque motor, or a synchronous motor, among others. Preferably, the actuator comprises a servo motor or a stepper motor. The driven shaft of the actuator transmits motion from the actuator to a driven component, including the exhaust gas valve. Preferably, the drive shaft is directly coupled to the electromagnetic components of the electric motor or is coupled to the electromagnetic components of the motor via a reduction gear transmission.

[0010] The exhaust gas valve comprises a valve member, such as a flap, attached to a driven shaft. The driven shaft is configured to receive rotational motion and / or torque from the actuator's drive shaft and transmit the torque and / or rotational motion to the valve member. Preferably, the valve member, particularly the valve flap, and the driven shaft are non-rotatably connected to each other. In other words, the driven shaft and the valve member are connected in a torque-resistant manner. For example, the valve member can be welded to the driven shaft, or the valve member and the driven shaft can be cast as a single-piece unit. The valve member of the exhaust gas valve is configured to be movable, particularly within a preferably tubular section of the exhaust passage. This is intended to selectively open or close a section of the exhaust passage for the transmission of exhaust gases and / or sound. In particular, the exhaust gas valve may comprise a tubular section of the exhaust system in which a flap is disposed. The flap is dimensioned to close a cube. The shape of the flap can correspond to the shape of the internal cross section of the tubular section. The driven shaft is preferably disposed perpendicular to the orientation of the tubular section. The driven shaft may be guided within the tubular section through an opening provided with a seal. The driven shaft defines a shaft axis about which the valve member may rotate. The drive shaft defines a drive axis. In a preferred embodiment of the valve system, the drive shaft and the valve axis are coaxially aligned. Alternatively, the valve axis may be offset relative to the drive shaft, in particular angularly offset relative to the drive shaft and / or radially offset. A valve axis that is radially and angularly offset relative to the drive shaft may be described as being tilted relative to the drive shaft.

[0011] The valve member may be positioned in a number of different positions within the pipe section, i.e., a position where the valve member completely closes the internal cross section of the cubic section, or a position where the valve member presents minimal obstruction to the exhaust gases flowing through the tubular section. The valve member may be oriented within the tubular section so as to be aligned with the midline of the tubular section, thereby minimizing the flow resistance presented to the exhaust gases by the valve member, particularly the flap. The valve member may be positioned in a number of different positions between 0° relative to the midline of the pipe section and 90° relative to the midline of the pipe section. In a preferred embodiment, the position of the valve member relative to the pipe section of the exhaust gas valve may be continuously, particularly steplessly, variable.

[0012] The coupling device is configured to transmit motion and / or torque from the drive shaft to the driven shaft. The coupling device itself defines a rotation axis. The coupling device may further comprise a connecting rod. The connecting rod is received in the slot such that the rod translates relative to the holder in the direction of the rotation axis. The connecting rod can move parallel to the rotation axis in the slot. The connecting rod is received in the slot in a manner without play in the circumferential direction relative to the rotation axis. The coupling device further comprises an elastic element, in particular a spring, which biases the connecting rod in the direction of the rotation axis and has an attachment section fixed to the holder. The elastic element may have a first end rigidly attached to the holder at the attachment section of the elastic element. The attachment section of the elastic element may be an end portion of the spring. The fixed attachment of the elastic element to the holder may be provided, for example, by welding, soldering, casting, adhesive bonding, etc. The connecting rod is biased in the slot in the direction of its translational movement by the elastic element. Any misalignment of the connecting rod in the slot in the first compression direction and / or the second tension direction, parallel to the rotation axis, is counteracted by the biasing force of the elastic element. The connecting rod may be the second end of the elastic element, e.g., a spring. The rotation axis of the coupling device is the axis about which the parts of the coupling device rotate and about which rotational motion is transmitted from the drive shaft to the driven shaft. The rotation axis of the coupling device is preferably oriented so that it is coaxially aligned with both the drive shaft and the valve axis, or angularly offset from but radially aligned with (intersects) both the drive shaft and the valve axis. The coupling device compensates for any misalignment of the drive axis of the drive shaft relative to the valve axis of the driven shaft.

[0013] The coupling device according to the present disclosure comprises a torsionally rigid retainer having an axially extending slot. The retainer provides sufficient rigidity so that operation of the exhaust gas valve apparently does not result in deformation of the retainer. Torque transmitted from the drive shaft to the driven shaft through the retainer practically does not cause deformation of the retainer. The maximum force of the actuator drive exerted on the torsionally rigid retainer causes deformation of the retainer relative to its axis of rotation of less than 1%, in particular less than 0.5%, and preferably less than 0.1%. The retainer can be manufactured using one or more different manufacturing methods, including lathing, milling, and sheet metal bending.

[0014] The retainer and the connecting rod are non-rotatably connected. The connecting rod preferably has no rotational play in the corresponding slot. Translational movement of the rigid member is similarly performed by the connecting rod, and vice versa. In the coupling device according to the present disclosure, movement of the connecting rod about the rotational axis is configured to accompany the same rotational movement of the retainer about the rotational axis. The connecting rod and the retainer rotate together about the rotational axis. In particular, when the coupling device is connected to an exhaust gas valve and an actuator, when the drive shaft rotates the retainer about the rotational axis, the connecting rod is configured to perform rotational movement about the same rotational axis as the retainer, so that the coupling device can transmit rotational movement to the driven shaft. In one preferred embodiment, the retainer is attached to the drive shaft, and the connecting rod is attachable to the driven shaft. Alternatively, the retainer is attachable to the driven shaft, and the connecting rod is attachable to the drive shaft. If the drive shaft is misaligned with respect to the driven shaft, the coupling device may preferably be configured to function as a Cardan joint to connect the drive shaft to the driven shaft.

[0015] The non-rotatable connection of the connecting rod to the retainer allows rotational motion or changes in position to be transmitted directly from the drive shaft to the driven shaft, even during sudden changes of direction, allowing for fast and accurate positioning of the valve while avoiding rattle noise. The separation of the connecting rod and retainer also allows the coupling device to thermally isolate the hot exhaust gas valve from the cold actuator while allowing for thermal expansion of the driven shaft.

[0016] Preferably, the elastic element is compressible in the axial direction. Alternatively or additionally, the elastic element is expandable in the axial direction. The elastic element may in particular comprise a rod-shaped mounting section at its first axial end and a connecting rod at its second axial end.

[0017] In particular, the coupling device may consist of an elastic element, a connecting rod, and a retainer. The rod-shaped mounting section, i.e., the mounting rod, may be oriented at an angle, preferably perpendicular, to the connecting rod. With respect to the rotation axis of the coupling device, the connecting rod may be oriented in a first transverse direction, and the mounting rod may be oriented in a second transverse direction. The angular arrangement of the mounting rod and the connecting rod with respect to each other may enable a Cardan function of the coupling device.

[0018] In one embodiment of the coupling device, the slot has opposing edges, particularly edges that face each other circumferentially relative to the rotation axis of the coupling device and that extend parallel to the rotation axis of the coupling device to guide the connecting rod translationally and transmit torque from the connecting rod to the retainer. The edges of the slot are similarly configured to transmit torque from the retainer to the connecting rod. The opposing parallel edges of the slot are preferably spaced apart from each other by a distance that essentially corresponds to the outer width diameter of the connecting rod. By providing the slot with opposing guide edges that are spaced apart according to the width or diameter of the connecting rod, the position of the valve member can be precisely controlled by the actuator. The actuator can reach not only the open and / or closed end positions of the valve, but also any intermediate positions of the valve member. The edges of the slot can function as a plain bearing to guide the connecting rod.

[0019] The width of the edge may be equal to or greater than the width or diameter of the connecting rod. Preferably, the width of the edge is at least 0.2 times, particularly at least 0.5 times, and preferably at least 0.8 times the width of the connecting rod. Alternatively or additionally, the width of the edge is less than 5 times, particularly less than 2 times, and preferably less than 1.5 times the width of the connecting rod.

[0020] According to one embodiment of the coupling device, the elastic element attached to the retainer is torque-free and / or axially bias-free. The retainer and the elastic element are preferably adapted to each other such that they do not exert torque, compression, or tension on each other in the rest state of the coupling element. In particular, the connecting rod is received in the slot and / or the mounting section is fixed to the retainer so that no torque and / or axial force from the elastic element is input to the retainer in the rest state of the coupling device. The rest state may particularly refer to a state in which the fully assembled coupling device is not attached to the drive shaft and / or the driven shaft of the valve assembly. The retainer and the elastic element may conform to each other such that no torque, compression, or tension bias is generated by the coupling device assembly. Alternatively, the retainer and the elastic element may be adapted to each other such that a bias, such as a tension or compression force, is exerted on each other in the axial direction, but no torque is exerted.

[0021] In an embodiment of the connecting device, the elastic member is particularly configured to comprise a coil spring, particularly a conical coil spring, preferably having a narrow end fixed to the connecting rod and / or a mounting section, preferably a wide end fixed to the mounting rod. The retaining section and, in particular, the conical coil spring, can be connected to each other in a space-saving manner. The shape of the coil spring can be determined by a first, particularly outer diameter, at a first axial end of the coil spring, a second, particularly inner diameter, at a second axial end of the coil spring opposite the first end, the axial extent of the coil spring, and the width, in particular the thread thickness, of the coil spring. In particular, the constant and / or maximum outer diameter of the coil spring is at least 20 mm, at least 25 mm, or at least 30 mm. Additionally or alternatively, the constant and / or maximum outer diameter of the coil spring is at most 60 mm, at most 50 mm, or at most 40 mm. In one embodiment, the constant and / or maximum outer diameter of the coil spring may be 36 mm ± 1 mm. The spring width of the coil spring, particularly the thread thickness, may be particularly constant. The spring width may be particularly at least 1 mm, at least 1.5 mm, or at least 2 mm. The spring width may be particularly at most 3.5 mm, at most 3 mm, or at most 2.5 mm. In particular, the spring width may be 2.5 mm ± 0.1 mm. The cylindrical coil spring may be configured to have an axial height of at most 30 mm, particularly at most 25 mm, or at most 15 mm. The cylindrical coil spring may be configured to have an axial height of at least 7.5 mm, particularly at least 10 mm, or at least 12 mm. The cylindrical coil spring may have a pitch of at least 1.5 and / or at most 5, particularly 2 to 4. Advantageously, the coil spring has a relatively small moment of inertia when moved about its axis of rotation and can act as a thermal insulator for thermally isolating the actuator from the exhaust gas valve in the direction of the axis. The coil spring is also advantageous in that it can be designed to have little unbalance about the axis of rotation. Preferably, the coil spring surrounds the retaining portion in a circumferential direction relative to the axis of rotation of the coupling device.

[0022] In a preferred further development, the coil spring may be a conical coil spring having a mounting section, in particular a narrow end fixed to the mounting rod, and a wide end fixed to the connecting rod. A conical coil spring is defined by a conical shape in which one first end of the coil spring is wider than the second end of the coil spring. The maximum outer diameter of the conical coil spring may in particular correspond to the above-mentioned dimensions of a typical coil spring. The minimum inner diameter of the conical coil spring may in particular be located at the axial end opposite the spring end having the maximum outer diameter. The minimum inner diameter of the conical coil spring is smaller than the maximum outer diameter minus the spring width. In particular, the minimum inner diameter of the conical coil spring is at least 10 mm, or at least 15 mm. Alternatively or additionally, the minimum inner diameter of the conical coil spring is less than 30 mm, less than 25 mm, or less than 20 mm. In particular, the conical coil spring has a minimum inner diameter of approximately 16 mm ± 1 mm. The conical coil spring may be configured with an axial height of at most 30 mm, in particular at most 25 mm, or at most 22.5 mm. The conical coil spring may be configured with an axial height of at least 10 mm, in particular at least 15 mm, or at least 20 mm. The conical coil spring may have a pitch of at least 2 and / or at most 10, in particular 4-6.

[0023] In a further development of the coupling device that can be combined with the above-described embodiment, the elastic element, particularly the coil spring, and the connecting rod are integrally formed, particularly as a filament, preferably with a constant diameter. The connecting rod and the remainder of the elastic element, particularly the coil spring, may have a constant filament diameter along the entire length of the filament. A coupling device having an elastic element with a mounting rod at its mounting end may have the same constant filament diameter in the mounting rod. The mounting rod and the elastic element, including the connecting rod, may preferably be integrally formed. In particular, the filament sections forming the straight connecting rod and the filament sections forming the straight mounting rod may be arranged crosswise, particularly at a 90° angle. Alternatively, the connecting rod and the mounting rod may be arranged parallel to each other. Preferably, the angle between the connecting rod and the mounting rod is less than 60°, particularly less than 30°, and most preferably less than 10°. Such a coupling device may in particular consist of a connecting rod and a coil spring including a rigid retainer.

[0024] According to an embodiment of the coupling device that can be combined with the preceding embodiments, the retaining portion is specifically configured to include a sheet metal part having a central section and two bent portions bent in a first direction relative to the central section, preferably parallel to the rotation axis, the two bent portions forming slots for retaining the connecting rod. Using a single sheet metal part to provide the retaining portion of the coupling device has been shown to provide maximum torsional rigidity with minimal weight. The central element of the sheet metal retaining portion may be flat and intersect the rotation axis of the coupling device. The bent portion or portions of the retaining portion may preferably extend parallel to the rotation axis and diametrically opposite each other in a radial direction relative to the rotation axis. Thus, the axially extending slots may be formed in the axially extending flaps. The coupling device may be provided with a gap space between the flaps in the circumferential direction, thereby improving thermal insulation while avoiding unnecessary weight. The flaps extending from the central portion of the rigid retaining portion may function as pairs of guide posts surrounding respective slots through which the connecting rods are guided. Flaps forming the edges of the slots can function as guide rails for a sled-like connecting rod disposed between them. The retainer preferably has two diametrically opposed slots for receiving one connecting rod. The slots are disposed diametrically opposite each other relative to the axis of rotation, so that rotation of the connecting rod around the axis of rotation does not result in imbalance. In such an embodiment, the flaps of the retainer can also be disposed diametrically opposite each other relative to the axis of rotation to avoid imbalance. Preferably, the retainer has two opposing bent portions, each including a respective slot for receiving the same connecting rod. The retainer can have one or more gap spaces disposed adjacent to one or more bent portions along the periphery of the retainer. The gap spaces between adjacent bent portions in the circumferential direction can have a circumferential extent at least equal to or greater than that of each adjacent bent portion.Preferably, at least 50%, at least 60%, or at least 75% of the circumferential extent of the holding portion in a plane perpendicular to the axis of rotation A is realized by one or more void spaces between adjacent folded portions.

[0025] In a further embodiment of the connecting device, the holding part comprises, in particular consists of, a sheet metal part having a central section and two seams bent in a second direction relative to the central section, preferably parallel to the axial direction, and the seams forming at least one recess for holding the mounting section. The holding part may preferably have a central section from which two bent sections extend in a first direction and from which two seams extend in a second direction different from the first direction, preferably opposite the first direction. The central section may be designated as a saddle section. For ease of reference, the first direction may be referred to as "downward," and the second direction may be designated as "upward." It is clear that connecting devices with seams do not require a convex portion of the central section, such as a bent portion, toward the upper first side. In the case of a mounting rod forming the mounting section, a recess may be designed to hold the mounting rod. The mounting section is preferably firmly fixed to the seam of the holding part, for example by welding, molding, or gluing. The recess may be a U-shaped opening extending in the opposite direction to the slot of the retainer. Alternatively, at least one or all of the recesses of the retainer may form a closed circular (O-shaped) opening that is open only in one direction transverse to the axis of rotation. Any relative movement of the mounting section, preferably the mounting rod, parallel to the axis of rotation or in the circumferential direction relative to the axis of rotation is thereby prevented by form-fitting engagement of at least one recess with the mounting section. The retainer may include one or more void spaces disposed adjacent to the seam or seams along the circumference of the retainer. The void spaces between adjacent seams in the circumferential direction may have a circumferential extent at least equal to or greater than that of each adjacent seam. Preferably, at least 50%, at least 60%, or at least 75% of the circumferential extent of the retainer in a plane perpendicular to the axis of rotation A is realized by the void space or spaces between adjacent seams.

[0026] According to an alternative embodiment of the seamless coupling device, which is compatible with one of the above-described embodiments, the holding part has a central plate section between the bent parts, which is directly connected to the mounting part. By providing the holding part with a central plate section, preferably intersecting the rotation axis, the mounting part, in particular the mounting rod, can be attached to the central plate section on or near the rotation axis, for example by welding, molding, or gluing. The central plate section of the holding part can have a preferably straight mounting bridge, which can be arranged corresponding to the mounting part, in particular the mounting rod. This allows the mounting part and the mounting bridge to be mutually engaged with corresponding engaging parts of the drive shaft or driven shaft.

[0027] In alternative embodiments, the retainer may comprise or be configured as a hollow cylindrical body, particularly a cylindrical body having a constant diameter or a stepped diameter with at least a middle section including a recess and a wide section including a slot. A hollow cylindrical body can be easily manufactured from a tubular body and can provide high torsional stiffness with a relatively small wall thickness while having a small moment of inertia. The hollow cylindrical body may have a circular cylindrical shape. Alternatively, the hollow cylindrical body may have at least two stepped sections, i.e., one with a narrower diameter and one with a wider diameter relative to each other. The narrow section includes at least one recess for retaining the mounting section of the elastic element, and the wide section includes a slot for receiving the connecting rod. Particularly in combination with an elastic element formed as a conical coil spring, a retainer having a stepped cylindrical body can minimize the space required for the connecting element. The graduated cylindrical body may have one or more intermediate steps between the narrow and wide diameter sections. The wall strength of the hollow cylindrical body is preferably constant across all steps. The graduated hollow cylindrical body may have a conical shape tapering from the narrow section to the wide section. The hollow cylindrical body may be sleeve-shaped with two opposing open ends and a through-hole between them, or cup- or can-shaped with a section closed at one or both ends. The retainer may have one or more void spaces disposed in the cylindrical body along the circumference of the retainer. The void spaces between circumferentially adjacent recesses and / or slots may have a circumferential extent at least equal to or greater than that of one or more adjacent cylindrical body sections. Preferably, at least 50%, at least 60%, or at least 75% of the circumferential extent of the retainer in a plane perpendicular to the rotation axis A is realized by one or more void spaces between adjacent cylindrical body sections.

[0028] In particular, the wall thickness of the sheet metal holder and / or holder with a cylindrical body is at least 0.5 mm, at least 0.75 mm, or at least 1 mm. The wall thickness of the holder is in particular at most 3 mm, at most 2.5 mm, or at most 2 mm. In particular, the wall thickness may be 1.5 mm ± 0.1 mm.

[0029] In certain embodiments of the coupling device, the retainer includes at least one void space or void spaces extending along the direction of the rotation axis. In particular, the void space or void spaces may extend between cylindrical body sections of the hollow cylindrical body. Alternatively, the void space or void spaces may extend between adjacent bends and / or seams. Preferably, the void spaces between circumferentially adjacent bends, seams, or body sections may have a circumferential extent at least equal to or greater than that of each adjacent bend, seam, or body section. The void spaces may function as cooling elements and / or reduce the thermal mass of the retainer, improving thermal insulation between the connecting rod and the mounting section.

[0030] Another aspect of the present invention relates to a valve system including an actuator having a drive shaft, an exhaust gas valve having a driven shaft, and a coupling device connecting the driven shaft to the drive shaft with an axial clearance. The coupling device may be configured as described above. The coupling device may provide axial, radial, and / or angular clearance, but not rotational clearance, between the driven shaft and the drive shaft, thereby converting rotational motion of the drive shaft about the drive shaft into corresponding rotational motion of the driven shaft about the valve axis. Preferably, the magnitude of the rotational motion of the drive shaft is converted into corresponding, preferably equal, rotational motion of the driven shaft. The coupling member may function as a Cardan joint between the driven shaft and the drive shaft, thereby converting rotational motion of the drive shaft into rotational motion of the driven shaft about the valve axis according to a predetermined motion function known to those skilled in the art. The coupling device provides a torque-resistant or rotationally rigid joint between the drive shaft of the actuator and the driven shaft of the exhaust gas valve. This allows accurate positioning of the exhaust gas valve member by the actuator and avoids rattle noise.

[0031] In a further development of the valve system, the mounting section of the elastic element and / or a section of the retainer fixed to the mounting section connects to the drive shaft. In embodiments in which the retainer comprises a central plate section including a mounting bridge, both the mounting bridge and the mounting section are engageable by an engaging portion of the drive shaft. This allows rotational motion to be transmitted directly from the drive shaft to the mounting bridge and the mounting section, such that the retainer and the elastic element move together without rotational play between them. By connecting the mounting section of the elastic element, or at least a corresponding section of the retainer directly connected thereto, to the drive shaft, rotational motion of the drive shaft can be transmitted directly to the coupling device.

[0032] In a further development of the valve system that can be combined with the above, the system includes an adapter for form-fitting engagement with a drive shaft or a driven shaft, particularly an engagement portion of the drive shaft or driven shaft, the adapter surrounding the mounting section of the elastic element. The adapter may completely or partially surround the mounting section, preferably the mounting rod, in the circumferential direction. The adapter may be an annular sleeve or a U-shaped bushing for providing form-fitting engagement with both the mounting section and the drive shaft or driven shaft. Since the actuator may be a mass-produced electric motor, the mounting section of the drive shaft may be formed corresponding to the manufacturer's specifications of the electric motor, where various actuators from various manufacturers may have different dimensions. The correspondingly formed adapter may help to match the size of the mounting section, particularly the mounting rod, which may be determined by the thread diameter of the spring coil, to a corresponding receptacle on the drive shaft. By providing the adapter between the mounting section and the engagement section of the drive shaft or driven shaft, true torque transmission without play can be provided in a simple manner. Alternatively or additionally, a coupling adapter may be provided on the connecting rod and a corresponding mating section of the driven or drive shaft.

[0033] According to one embodiment of the valve system, the drive shaft and / or the driven shaft respectively achieve one or two contact lines with a corresponding engaging part of the coupling device, in particular the connecting rod, the mounting section, or a section of the holder fixed to the mounting section. The drive shaft or the driven shaft in particular achieves a single contact line with a corresponding part of the coupling device, in particular the preferably thread-shaped rod section of the connecting rod or the mounting section. In one preferred embodiment, the upper contact with the drive shaft is preferably achieved by a single contact line with the mounting section, and the lower contact with the drive shaft is preferably achieved by a single contact line with the connecting rod. Alternatively or additionally, the drive shaft or the driven shaft may achieve two diametrically opposed contact lines, in particular with a section of the holder fixed to the mounting section. Preferably, the upper contact with the drive shaft of the coupling device is achieved by two contact lines.

[0034] According to one embodiment of the valve system, torque is transmitted from the drive shaft to the driven shaft via the rigid retainer. Preferably, torque is transmitted exclusively from the drive shaft to the driven shaft via the rigid retainer. In particular, even when torque is transmitted from the drive shaft to the driven shaft, the elastic element remains free from torque because the torque is transmitted via the rigid retainer. In particular, the helical section of the coil spring may be free from torque. For example, torque received by one of the connecting rod or the mounting section is transmitted to the retainer and then transmitted via the retainer to the other of the mounting section or the connecting rod, thereby preventing the elastic element from receiving torque. The elastic element, in particular, is subjected to tension in the direction of the rotation axis when attached to the shaft alongside the torque-transmitting rigid retainer. Alternatively, in the installed state of the valve system, the elastic element may remain free from tension, in particular free from compressive and / or ductile bias.

[0035] The present invention also relates to a method for assembling a coupling device such as the one described above, the method comprising: (a) providing a retainer comprising a slot and a recess; (b) providing a coil spring comprising a connecting rod and an attachment section; (c) fitting the connecting rod into the slot of the retainer; (d) fitting the mounting section into the recess of the retainer; Equipped with.

[0036] Unlike prior art assembly methods that are laborious and overly complicated, the above-described design of the coupling device allows for very simple and quick installation of the coupling device. Assembly according to the above-described method may advantageously alternatively include performing step (c) before step (d), or performing step (d) before step (c). The assembly method may be performed by first fitting the connecting rod into the slot of the retainer and then fitting the mounting section into the recess of the retainer. Alternatively, the assembly method may be performed by first fitting the mounting section into the recess of the retainer and then fitting the connecting rod into the slot of the retainer. It may be advantageous to first fit either the connecting rod or the mounting section of the coil spring into the slot or recess of the retainer and, if possible, secure them. This limits the possibility of the coil spring moving relative to the retainer and makes it easier to manipulate the coil spring and the retainer relative to each other. For example, the purpose of this is to apply tension to the spring to stretch it, or compress it to make it easier to fit the other part, i.e., the mounting section or the connecting rod, into its respective receptacle, i.e., the retainer.

[0037] In one embodiment, between steps (c) and (d), the retainer is rotated within the coil spring. It is clear that rotation of the retainer within the coil can occur after step (c) but before step (d), or after step (d) but before step (c). Preferably, the retainer is rotated from a first axial alignment within the coil spring to a second axial alignment within the coil spring. Axial alignment of the coil spring and the retainer occurs, for example, when the rotation axis of the retainer and the axis of symmetry of the coil spring are preferably coaxially aligned. By providing the retainer within the coil spring, the overall moment of inertia of the coupling device is reduced by locating the relatively solid and heavy retainer closer to the rotation axis of the coupling device. At the same time, by arranging the coil spring outside the retaining part surrounding the retaining part, the coil spring can be flexible in its axial extension as well as in its radial contraction, or, for example, in the case of a conical coil spring, the coil spring can undergo a greater elastic deformation in the axial direction relative to the overall size of the coupling device, since the subsequent windings of the coil spring are received spirally in the radial direction relative to one another. By providing the retaining part inside the coil spring, the coupling device can be designed to be lightweight and compact overall.

[0038] In a further development of the assembly method, the holder is translated at least once along its axis, along the mounting section, or along the connecting rod before, during, and / or after the rotation. The assembly method may take advantage of the situation where the slot for receiving the connecting rod and / or the recess for receiving the mounting section may have an opening extending longitudinally in the direction of the axis of the holder. The connecting rod and the slot move translationally relative to each other in the direction of the axis of the holder. Alternatively or additionally, during the assembly process, the mounting section and the recess may move translationally relative to each other along the axis of the holder. The relative movement in the direction of the axis of the holder may occur in whole or in part before the start of rotation or after the end of rotation in the rotation of the holder within the coil spring. A translational and rotational movement of the holder relative to the coil spring occurs, and it may be preferable that the translational movement along the axis of the holder and the rotational movement, preferably within the coil spring, preferably around the mounting section or around the connecting rod are performed simultaneously. In particular, the coil spring can stretch during rotation, preferably for the entire rotation or for a portion of the time required for the retainer to rotate within the coil spring. The ability of the retainer to move along its axis relative to the coil spring allows a relatively large retainer to fit within the coil and rotate. This allows the retainer structure to have a relatively large stiffness for transferring torsional stiffness from the driven shaft to the drive shaft.

[0039] The present invention further relates to a method for assembling the valve system described above. The valve system assembly method particularly comprises the above-described coupling device assembly method. In the valve system assembly method, the elastic element is preferably compressed in the axial direction when the coupling device is attached to the actuator and the exhaust gas valve. The coupling device needs to be prepared before being attached to the actuator or the exhaust gas valve. It may be preferable to attach the completed coupling device to the actuator first and then to the exhaust gas valve, or vice versa. After attaching the coupling device to either the actuator or the exhaust gas valve, the coupling device may be compressed before attaching it to the other of the exhaust gas valve or the actuator. In one embodiment, the elastic element of the coupling device may maintain a compressed state even after the coupling device is attached to both the actuator and the exhaust gas valve. In another preferred embodiment, the elastic element of the coupling device is decompressed after attachment to both the actuator and the exhaust gas valve to maintain no or substantially no compressive bias, i.e., less than 10% compressive bias, preferably less than 1% compressive bias.

[0040] Further embodiments, features and technical aspects are set forth in the dependent claims. Further details of preferred embodiments of the invention are shown in the accompanying drawings. [Brief explanation of the drawings]

[0041] [Figure 1] FIG. 1 shows an example of a valve system according to the invention, including an actuator, an exhaust gas valve and a coupling device. [Figure 2a] FIG. 2a shows a diagram illustrating a first embodiment of a coupling device according to the invention. [Figure 2b] Figure 2b shows another view of the first embodiment of the coupling device according to the invention. [Figure 2c] Figure 2c shows yet another view illustrating a first embodiment of a coupling device according to the invention. [Figure 3a] FIG. 3a shows one of a series of views illustrating the assembly of the coupling device according to FIGS. 2a to 2c. [Figure 3b] Figure 3b shows one of a series of views illustrating the assembly of the coupling device according to figures 2a to 2c. [Figure 3c] FIG. 3c shows one of a series of views illustrating the assembly of the coupling device according to FIGS. 2a to 2c. [Figure 3d] FIG. 3d shows one of a series of views illustrating the assembly of the coupling device according to FIGS. 2a to 2c. [Figure 3e] FIG. 3e shows one of a series of views illustrating the assembly of the coupling device according to FIGS. 2a to 2c. [Figure 3f] Figure 3f shows one of a series of views illustrating the assembly of the coupling device according to figures 2a to 2c. [Figure 4a] Figure 4a shows a view of a second embodiment of a coupling device according to the invention. [Figure 5a] Figure 5a shows a third embodiment of a coupling device according to the invention. [Figure 5b] Figure 5b shows a third embodiment of a coupling device according to the invention. [Figure 5c] Figure 5c shows a third embodiment of a coupling device according to the invention. [Figure 6a] Figure 6a shows a fourth embodiment of a coupling device according to the invention. [Figure 6b] Figure 6b shows a fourth embodiment of a coupling device according to the invention. [Figure 7a] FIG. 7a shows the assembly sequence of the coupling device according to FIGS. 6a and 6b. [Figure 7b] FIG. 7b shows the assembly sequence of the coupling device according to FIGS. 6a and 6b. [Figure 7c] FIG. 7c shows the assembly sequence of the coupling device according to FIGS. 6a and 6b. [Figure 7d] FIG. 7d shows the assembly sequence of the coupling device according to FIGS. 6a and 6b. [Figure 7e] FIG. 7e shows the assembly sequence of the coupling device according to FIGS. 6a and 6b. [Figure 7f] FIG. 7f shows the assembly sequence of the coupling device according to FIGS. 6a and 6b. [Figure 8a]FIG. 8a shows a coupling device with an adapter. [Figure 8b] Figure 8b shows the adapter used in Figure 8a. [Figure 8c] Figure 8c shows an alternative adapter. [Figure 9a] FIG. 9a shows a valve arrangement with a coupling arrangement according to FIG. 5a. [Figure 9b] FIG. 9b shows a valve arrangement with a coupling arrangement according to FIG. 5a. [Figure 10] FIG. 10 shows a schematic cross-sectional view of a valve assembly having the coupling device shown in FIG. 2a. DETAILED DESCRIPTION OF THE INVENTION

[0042] In the following description of preferred embodiments of the valve system or coupling device according to the invention, the same or similar reference numerals are used to designate the same or similar parts.

[0043] The coupling device according to the invention is designated as a whole by the reference number 1. The coupling device 1 comprises, as its main components, a torsionally rigid retainer 2 and an elastic element 4. The valve system according to the invention is designated as a whole by the reference number 7. The valve system comprises, as its main components, an actuator 3, an exhaust gas valve 5 and the coupling device 1.

[0044] In the exemplary embodiment shown in Figure 1, the valve system 7 comprises a coupling device 1 arranged between the actuator 3 and the exhaust gas valve 5 to transfer rotational motion from the actuator 3 to the exhaust gas valve 5. The actuator 3 has a drive shaft 31. The exhaust gas valve 5 has a driven shaft 51. The coupling device 1 connects the drive shaft 31 to the driven shaft 51 to transfer force and / or motion from the actuator 3 to the exhaust gas valve 5.

[0045] The coupling device 1 provides an axial clearance to allow for thermal expansion of the exhaust gas valve, etc. The coupling device 1 can be configured in particular as a Cardan element to compensate for a radial offset between the rotation axis A3 of the drive shaft 31 and the rotation axis A5 of the driven shaft 51. That is, if the axis A3 of the actuator 3 is not coaxially aligned with the axis A5 of the exhaust gas valve 5 but is radially offset, such radial offset can be compensated for by the coupling device 1.

[0046] Alternatively or additionally, the valve coupling device 1 may be configured to compensate for an angular offset between the axis of rotation A3 of the actuator 3 and the axis of rotation A5 of the exhaust gas valve 5. For example, if the axis of rotation A5 of the valve is tilted or canted relative to the axis A5 of the actuator 5, the coupling device 1 compensates for the misalignment and connects the valve 5 to the actuator 3, preferably in a non-rotational manner.

[0047] Due to the non-rotational connection between two components, such as the drive shaft 31 and the driven shaft 51, the two non-rotatably connected components rotate dependently on each other, preferably without rotational play. If one of the non-rotatably connected components rotates relative to a reference object, the other non-rotatably connected components are also forced to rotate relative to the reference object.

[0048] If the drive shaft 31 and the driven shaft 51 are non-rotatably connected to one another, any rotation of the drive shaft 31 will result in a corresponding rotational movement of the driven shaft 51, and vice versa. Those skilled in the art will recognize that if the axis A3 of the actuator is significantly tilted relative to the axis A5 of the valve 5, the corresponding rotational movement of the shafts 31, 51 will be determined by the characteristics of the Cardan connection between them. The lack of play in a non-rotatable connection prevents rattle noise due to loosening of the flap of the exhaust gas valve 5.

[0049] A first embodiment of a coupling device 1 is shown in a cross-section in Figure 2a and in two different perspective views in Figures 2b and 2c. In this embodiment, the elastic element 4 of the coupling device 1 is realized as a hollow cylindrical coil spring 41. The coil spring 41 has a first end that realizes a mounting section 42. A second end of the coil spring 41 realizes a connecting rod 45.

[0050] The torsionally rigid retainer 2 is connected to the elastic element 4. The retainer 2 comprises a hollow cylindrical body 28 having a stepped diameter. In this embodiment, the cylindrical retainer of the body 28 has a narrow section 81 and a wide section 83. The wall thickness of the cylindrical body 28 is essentially constant. The inner diameter d1 of the narrow section 81 is smaller than the inner diameter d3 of the wide section 83. The cylindrical body 82 has a conical step section 82 connecting the narrow section 81 to the wide section 83. The wide section 83 has a larger axial extent along the rotation axis A of the retainer 2 than the narrow section 81 and the conical section 82. Preferably, the axial extent of the wide section 83 is at least as large as the total axial extent of the narrow section 81 and the conical section 82 combined. Cylindrical body 28 may have one or more void sections, for example, in the cylindrical body section forming wide section 83 and / or in the cylindrical body section forming narrow section 81 (not shown).

[0051] The narrow section 81 includes a circular recess 24. The recess 24 may completely circumferentially surround the mounting section 42 received therein. Optionally, the retaining part 2 may further include a U-shaped, axially open recess 24'. The open recess 24' may be positioned diametrically opposite the recess 24. The mounting section 42 of the elastic element 4 may be fixed to the retaining part 2 by welding. The mounting section 42 is inserted into the recess 24 of the retaining part 2, the elastic element 4 is fixed to the retaining part 2, and the position of the recess 24 that receives the mounting section 42 prevents the mounting section 42 of the elastic element 4 from moving relative to the retaining part 2.

[0052] After the mounting section 42 of the elastic element 4 is fixed to the holding part 2, only the connecting rod 45 remains movable relative to the holding part 2.

[0053] As shown by the arrow m, the connecting rod 45 of the elastic element 4 is movable parallel to the direction A of the axis of the coupling device 1, which is defined by the holding part 2. However, the connecting rod 45 is prevented from rotating relative to the holding part 2 in the circumferential direction about the rotation axis A of the coupling device 1. The connecting rod 45 is received in the slot 25 of the holding part so that the rod 45 can only move relative to the holding part 2 in a direction parallel to the rotation axis A. When torque is applied to the connecting rod 45, the connecting rod 45 transmits the torque to the edge 27 of the slot 25. The edges 27 of the slot 25 are arranged opposite each other in the circumferential direction about the rotation axis A and are spaced apart from each other by a distance corresponding to the width of the connecting rod 45. The edges 27 of the slot 25 guide the connecting rod 45 so that the connecting rod 45 can move in the direction of the rotation axis A but cannot move in the circumferential direction about the rotation axis A. The edges 27 of the slot 25 can function as a plain bearing for the connecting rod 45.

[0054] The elastic element 4 is fixed to the holder 2 at its mounting section 42 by, for example, welding, adhesive bonding, overmolding, etc., and the connecting rod 45 is received in the slot 25 with substantially no play, so that the elastic element 4 is non-rotatably connected to the rigid holder 2. Therefore, torque acting on the connecting rod 45 or the mounting section 42 from external influences is transmitted to the torsionally rigid holder. For example, when the connecting rod 45 is subjected to torque, the connecting rod 45 transmits the torque to the body of the holder 2 via the edge 27 of the slot 25. The holder is designed with sufficient torsional rigidity to prevent torsional deformation of the holder 2, at least during normal operation. It may be preferable to design the holder 2 with sufficient torsional rigidity so that the maximum torque that the actuator 3 can provide to the linkage 1 via the drive shaft 31 causes a torsional deformation of the holder 2 of less than 0.1% or less than 0.01%. Torque received by the holder 2 from the connecting rod 45 can be transmitted to the mounting section 42 via the body 28 of the holder.

[0055] The slot 25 is arranged in the wide section 83 of the holder 2. The axial extent of the slot 25 in the cylindrical body 28 of the holder 2 is greater than the axial width, preferably the diameter, of the connecting rod 45, in particular at least 1.5 times the axial width, or at least 2 times the axial width of the connecting rod 45. The axial extent of the slot 25 in the cylindrical body 28 of the holder 2 is less than 10 times, preferably less than 5 times, and more preferably less than 3 times the axial width, preferably the diameter, of the connecting rod 45. The axial extent of the slot 25 in the bottom of the holder 2 is less than half the axial extent of the holder 2. In the assembled state of the coupling device 1, preferably in the assembled state of the valve system 7, the connecting rod 45 is completely received in the slot 24 in the direction of the rotation axis A. It is clear that the terms "in the direction of the rotation axis" and "in the axial direction" are used interchangeably in this disclosure.

[0056] Figures 3a to 3f show the sequence for attaching the elastic element 4 to the retaining part 2 and thus assembling the coupling device 1. Figure 3a shows the individual parts of the coupling device, namely its torsionally stiff retaining part 2 and its elastic element 4, side by side before assembly.

[0057] The elastic element 4 in this embodiment is realized as a cylindrical coil spring 41 having two end sections, which are the ends of the coil spring 41 relative to the helical spring body, so that the end sections extend generally radially relative to the rotation axis A4 of the coil spring 41. The first end section of the coil spring 41, which forms the mounting section 42, extends inwardly from the helical spring rod in a straight rod-like manner. The second end section, which forms the connecting rod 45, has a section 48 which extends radially inwardly in a straight rod-like manner and a circular arc section 47 which forms a curved portion between the rod sections 48.

[0058] The straight rod section 48 of the connecting rod 45 and the straight rod portion forming the mounting section 42 are preferably arranged at a perpendicular angle to each other. The straight mounting section extends in a first radial direction relative to the axis of rotation A, and the straight section 48 of the connecting rod 45 extends in a second radial direction relative to the axis of rotation A. This arrangement of the connecting rod 45 relative to the mounting section 42 is useful for the coupling device 1 to function as a Cardan joint.

[0059] Figure 3b shows the holder 2 set on the connecting rod 45 of the elastic element 4. The straight sections 48 of the connecting rod 45 are received in slots 25 in the wall of the cylindrical body 28 of the holder 2, diametrically opposite each other with respect to the axis of rotation A2 of the holder. When the holder 2 is set on the elastic element 4 as shown in Figure 3b, the axis of rotation or symmetry A4 of the elastic element 4 and the axis of rotation A2 of the holder 2 may be coaxially aligned. At this point in the assembly of the coupling device 1, the mounting section 42 is not yet received in the recess 24, 24'.

[0060] FIG. 3c shows how the retainer 2 rotates around the connecting rod 45 within the coil spring 41. The coil spring 41 has a constant outer diameter of approximately 36 mm. As described above, the hollow cylindrical body 28 of the retainer 2 has a graduated diameter and includes a narrow section 81, a conical section 82, and a wide section 83. During rotation of the retainer 2 around the connecting rod 45 in the coil spring 41, the arc section 47 secures the retainer from sliding radially off the connecting rod 45. The arc section 47 has a range of essentially 180° about the axis of rotation. The arc section 47 and the rod section 48 are formed by a coil spring filament and have the same thickness as the rest of the coil spring 41, approximately 1.5 mm. The outer diameter of the arc section is approximately 17 mm.

[0061] 3d shows a state in which the holder 2 has been rotated around the connecting rod 45 so that a section of the holder body 28, in this example the narrow section 81 that was initially facing away from the mounting section 42, now faces the mounting section 42. In the stage shown in FIG. 3b the holder 2 was located mainly outside the coil spring 41, but in the stage shown in FIG. 3d it is located mainly inside the coil spring 41. If the mounting section 42 is not inserted into the corresponding recess 42, the spring 41 may be stretched in the direction of the rotation axis A.

[0062] Figure 3e shows the elastic element 4 and the retainer 2 in essentially the same state as in Figure 3d. The mounting section 42 is not fully inserted into the corresponding recess 24, so that the axis A2 of the retainer is slightly inclined relative to the axis A4 of the spring. To insert the mounting section 42 into the recess 24, the mounting section may be biased towards the outside of the coil spring 41, which then allows the end of the coil spring 41 forming the mounting section 42 to smoothly move radially into the recess 24. The mounting section 42 may then be rigidly attached to the retainer 2, thereby securing it thereto.

[0063] 3f shows the final assembled state of the coupling device 1, with the mounting section 42 received in the recesses 24, 24' of the holder 2 and the connecting rod 45 positioned in the slot 25. In this state, the axis of rotation A2 of the holder and the axis of rotation A4 of the spring are concentrically aligned to form the axis of rotation A of the coupling device 1.

[0064] A different embodiment of the coupling device 1 is shown in a cross-section in Fig. 4a and in two different perspective views in Fig. 4b and Fig. 4c. Assembly of the coupling device 1 according to Fig. 4a can be carried out in the same manner as the above-described assembly of the coupling device according to Figs. 2a to 3f. Alternatively, to assemble the elastic element 4 and the holding part 2 of the coupling device 1 according to Fig. 4a together, the mounting section can first be placed in the recess 24, and then the holding part 2 can be rotated in the coil spring 43, so that the connecting rods 42 can then be inserted into the respective slots 25. Such an assembly method will be described below with reference to the coupling device shown in Figs. 6a to 7e.

[0065] In the embodiment shown in Fig. 4a, the shape of the retaining portion and the elastic element 4 differs slightly from those of the previously described embodiment, but otherwise the function of the coupling device 1 according to Fig. 4a and its structure correspond to those of the previously described embodiment. In addition to the recesses 24 and the slots 25, the cylindrical body 29 is formed with a void space 64 extending through the cylindrical body 29 in the axial direction A. The void space 64 separates the body sections of the cylindrical body 29 in the circumferential direction and serves as a thermal barrier for insulating the mounting section 42, which may be attached to the high-temperature valve, from the connecting rod 45, which may be attached to the drive actuator.

[0066] The holding part 2 is composed of a hollow cylindrical body having a continuously constant inner diameter and outer diameter. The width of the wall of the hollow cylindrical body 29 is approximately the same as the width of the filamentous member forming the coil spring 40. The strength of the wall of the hollow cylindrical body 29 may be 0.5 to 2.5 times the width of the filamentous member of the coil spring 43.

[0067] The elastic element 4 according to the embodiment of the coupling device 1 shown in FIG. 4a is realized as a conical coil spring 43. The coil spring 43 is tapered from a wide end, where the coil spring 43 terminates in the mounting section 42, to a narrow end, where the coil spring 43 terminates in the connecting rod 45. The wide end of the conical coil spring 43 has an outer diameter of approximately 35.5 mm. The narrow end of the conical coil spring 43 has an inner diameter of approximately 16.5 mm. The width or diameter of the thread-like element forming the coil spring 43 is approximately 1.5 mm. Both the connecting rod 45 and the connecting section 42 of the elastic element 4 according to the embodiment shown in FIG. 4a are composed of straight rod sections 48. The rod sections 48 forming the mounting section 42 on the one hand and the connecting rod 45 on the other hand extend perpendicular to each other, allowing the coupling device 1 to function as a Cardan element.

[0068] Figure 5a shows a third embodiment of the coupling device 1. The elastic element 4 of the coupling device 1 shown in Figure 5a is essentially the same as the elastic element described above for the embodiment shown in Figures 2a to 3f.

[0069] The holding part 2 is realized as a bent sheet metal body with a bent section 23 bent in the direction of the rotation axis A. The sheet metal part shown in Figures 5a to 5c has a first central section 20 extending in a radial plane relative to the rotation axis A and two bent sections 23a protruding from the central section 20 in the direction of the rotation axis A.

[0070] The coupling device 1 shown in FIG. 5a has a holding part made of sheet metal parts. The central section 20 is fixed to the mounting section 42 of the holding element 4. The central section 20 can be, for example, welded, glued, or otherwise rigidly attached to the mounting section 42 of the elastic element 4. In the exemplary embodiment shown in FIG. 5a, the elastic element is realized as a coil spring 41 with a constant diameter. The elastic element 4 and the mounting section 42, as well as its connecting rod 45, are made of thread-like members with a constant diameter. The elastic element 4 of the embodiment shown in FIG. 5a essentially corresponds to the elastic elements of the embodiments shown in FIGS. 2a to 3f.

[0071] The central section 20 of the sheet metal holder 2 has a bridge section 20a surrounded on two opposite sides by openings 21. The bridge section 20a of the central section 20 intersects the rotation axis A and has a width corresponding to the width of the mounting section 42. The openings 21 on both sides of the bridge section 20a allow for an engagement section between the drive shaft and, for example, both the bridge section 20a and the mounting section 42 of the elastic element via the openings 21. The engagement section allows torque to be transmitted between the shaft and the coupling device 1 without creating torsional stress between the mounting section 42 of the elastic element and the corresponding section of the holder 2 to which the mounting section 42 is fixed. In this example, the straight rod-shaped end of the coil spring 41 forming the mounting section 42 is aligned parallel to the bridge section 20a, which extends radially relative to the rotation axis A, as shown in FIG. 5c.

[0072] The sheet metal part has a thickness similar to the width of the thread-like element of the coil spring 41. The width of the bent sections 23a of the sheet metal holder 2 is less than 10 times, preferably less than 5 times, the width of the connecting rod 45 in the circumferential direction around the rotation axis A. A gap space 65 exists between the opposing bent sections 23a.

[0073] Figure 6a is a cross-sectional view of a further embodiment of the coupling device 1. The coupling device 1 of Figure 6a is shown in another view in Figure 6b, and assembly steps of the coupling device 1 of Figure 6a are shown in Figures 7b to 7e.

[0074] The recess 24 of the holder 2 shown in Fig. 6a is angularly surrounded by the sheet metal body so that the mounting section 42 can contact two opposing limit stops in the direction of the rotation axis. An upper and / or a lower limit stop can serve for the assembly of the mounting section 42 to the holder 2, in particular for torque-resistant fastening.

[0075] The elastic element 4 of the coupling device 1 of Fig. 6a is realized as a conical coil spring 43. The coil spring 43 of Fig. 6a tapers from the end realizing the rod-like straight end 48 realizing the mounting section 42 towards the rod-like straight end 48 realizing the connecting rod 45. Therefore, with regard to the elastic element 4, reference is made to the description of the embodiment shown in Fig. 4a.

[0076] In the embodiment shown in FIG. 6a, the holding part 2 is realized as a sheet metal part having two first, upwardly bent bends 23b with slots 25 for receiving connecting rods. The sheet metal part realizing the holding part 2 further comprises two seams 22b bent in a second, downward direction (opposite to the first direction). These seams 22b are provided with recesses 24 for receiving the mounting sections 42 of the elastic element. Those skilled in the art can imagine that the sheet metal part realizing the holding part 2 may be formed into an overall cross shape before bending, with two diametrically opposed arms of the cross bent in a first direction and two diametrically opposed arms bent in a second direction. The holding part 2 has a central section 20 from which the bends 23b extend upward and the seams 226 extend downward.

[0077] In Figure 7a, the retainer is shown by itself next to a conical coil spring 43. Diametrically opposed bends 23b may preferably be shaped as mirror images of one another. Similarly or alternatively, diametrically opposed seams 22b of retainer 2 may preferably be shaped as mirror images of one another. The symmetry of bends 23b and / or seams 22b of retainer 2 advantageously reduces imbalance.

[0078] Each of the bent portions 23b has a slot 25 for receiving a connecting rod 45. In FIG. 6a, the slot 25 is U-shaped and open in the direction of the rotation axis A. This allows the connecting rod 45 to be easily inserted into the holder. The bent portions 23b form edges 27 that are spaced apart from each other and correspond to the width of the connecting rod 45. The slot edges 27 serve as guides that allow the connecting rod 45 to be fully translated relative to the sheet metal body of the holder 2. Therefore, when torque is applied to the connecting rod 45, for example, from the corresponding connecting section of the drive shaft 31 or the driven shaft 51, the torque can be transmitted directly from the connecting rod 45 to the holder 2 without play.

[0079] FIG. 7a shows the holder 2 next to the elastic element 4 in a pre-assembly state. As a first assembly step, according to FIG. 7b, the rod-shaped mounting section 42 of the coil spring 43 can be inserted into the recess 24 of the seam 22b. In the embodiment shown in FIGS. 6a to 7e, the recess 24 for receiving the mounting section 42 provides a clearance for the mounting section 42 to move in the direction of the rotation axis A during assembly. The recess 24 can also be dimensioned to include circumferential play with respect to the rotation axis A of the holder 2 during assembly. In the direction of the rotation axis A of the holder 2, the mounting section 42 can move over its width, preferably several times its diameter, e.g., two or three times its width. Between the assembled state shown in FIG. 7b and the assembled state shown in FIG. 7c, the mounting section 42 moves in the recess 24 in the direction A2 of the rotational movement of the holder, thereby smoothly moving the seam 22b into the space enclosed by the spring 43.

[0080] Figure 7d shows the retainer 2 being rotated about the mounting section 42 within the coil spring 43. Figure 7e shows the retainer 2 after being rotated approximately 100° relative to the mounting section 42 from the position shown in Figure 7c. Between the state shown in Figure 7c and the state shown in Figure 7e, the mounting section 42 remains in the recess 24 of the seam 22b. While the bent portion 23b initially faces away from the coil spring 43 and away from the connecting rod in Figures 7b and 7c, in Figure 7e it is shown facing towards the connecting rod 45. The connecting rod 45 can be received in the slot 25 as shown in Figure 3b.

[0081] The holder 2 moves in the direction of its rotation axis A2 and reaches the final assembly position, as shown in Figure 7f. The holder 2 moves relative to the mounting section 42 so that the holder 2 moves more smoothly inside the coil spring 43. After the connecting rod 45 is received in the slot 25, as shown in Figure 6b, the mounting section 42 is fixed so as not to rotate relative to the holder 2 by, for example, welding or soldering the mounting section 42 to the seam 22b, or by overmolding the seam 22b, or by some other means, to rigidly attach the mounting section 42 to the holder 2.

[0082] As can be easily inferred from FIG. 6a, the retaining portion 2 shown in FIGS. 6a-7f can be made with less material while leaving large circumferential gap spaces 65, 66 between the bent portions 23b and between the seams 22b. The gap spaces 65, 66 between adjacent bent portions 23b or seams 23b can have a circumferential extent at least longer or larger than that of each adjacent bent portion 23b or seam. Preferably, at least 50%, at least 60%, or at least 75% of the circumferential extent of the retaining portion 2 in a plane perpendicular to the rotation axis A is realized by one or more gap spaces 65, 66 between adjacent bent portions 23b or seams 22b. The retaining portion 2 and the attached spring 43 thus form a very lightweight coupling device 1. Such a coupling device 1 can be easily and accurately moved by the drive actuator 3 and also acts as a highly efficient thermal insulator between the drive shaft 31 and the driven shaft 51 .

[0083] Another embodiment of a coupling device is shown in Figure 8a. The coupling device 1 comprises a cylindrical coil spring 41. The coil spring 41 is attached to a sheet metal holder 2 which comprises a bent portion 23c extending in a first direction parallel to the axis of rotation A of the coupling device 1 and a seam 22c extending in a second, opposite direction. The holder shown in Figure 8a differs from the one described above with reference to Figures 6a to 7f in that the seam 22c is shorter and has a recess 24 formed in it similar to that of the embodiment shown in Figure 2a.

[0084] In particular, Figure 8a shows a U-shaped bushing 53a that surrounds the mounting section 42 and acts as an adapter between the coupling device 1 and an engagement section of the driven or drive shaft (not shown in further detail). An exemplary embodiment of the U-shaped bushing is shown in Figure 8b, and a cylindrical shaped bushing 53b is shown in Figure 8c.

[0085] The valve assembly 7 shown in Figures 9a and 9b shows the engagement section 33 engaging two diametrically opposed contact lines 72 of the coupling device 1. Figure 9a shows a side view of the assembly 7, and Figure 9b shows a cross-sectional view taken along line J-J in Figure 9a. The driven shaft 51 is shown schematically. The engagement section 33 of the drive shaft 31 extends into the coupling device 1 through the opening 22 in the retainer 2. The engagement section 33 firmly grips the bridge section 20a of the retainer 2. The engagement section 33 does not directly contact the mounting section 42 or any part of the resilient element 4. However, the engagement section 33 engages the retainer 2 at its section attached to the mounting section 42.

[0086] 9a, 9b and 10 are essentially the same as each other. In alternative embodiments, it may be preferred that the mounting section 42 of the elastic element, or a corresponding part of the holding part 2, is attached to the drive shaft 31, while in alternative embodiments the mounting section or the corresponding section of the holding part 2 may be attached to the driven shaft 51.

[0087] FIG. 10 shows a valve assembly 7 with an electric motor 3 having a drive shaft 31 with an engagement section 33. The driven shaft 51 is shown diagrammatically. The end of the mounting section 42 of the elastic element 4 rests on the engagement portion 33. A single contact line 71 is realized between the mounting section 42 and the drive shaft 31. The coupling device 1 shown in FIG. 10 corresponds to that described with reference to FIG. 2a. Alternatively, another coupling device such as that described with reference to FIG. 4a, 6a, or 8a may be provided. The mounting section 42 of the coupling device 1 is rigidly held in the engagement section 33. Rotation of the drive shaft 31, driven by the actuator 3, forces the mounting section 42, and thus the entire coupling device 1, to perform a corresponding rotational movement. The engagement section 33 engages the coupling device 1 in a torque-resistant manner.

[0088] 10 shows that the engagement section 33 clamps onto the mounting section rod 48. The engagement can be form-fitting in the direction of rotation about the axis of rotation A. Alternatively, a radial clamping force can hold the coupling device 1 against the engagement section 33. Alternatively or additionally, an axial bias 4 on a resilient element 4 between the drive shaft 31 and the driven shaft 50 can help hold the coupling device 1 in place.

[0089] The features disclosed in the above description, the drawings and the claims may, both individually and in any combination, be important for the realization of the invention in its various embodiments. [Explanation of symbols]

[0090] 1 Coupling device 2 Torsional rigidity retaining section 3 Actuators 4 Elastic Elements 5 Exhaust gas valve 7 Valve System 20 Central Section 20a bridge section 21 Aperture 22b seam 22c seam 23a Bend part 23b Bend part 23c Bend part 24 recess 25 slots 27 Edge 28 Cylindrical body 29 Cylindrical body 31 Drive shaft 33 Engagement Section 41 Coil spring 42 Mounting Section 43 Coil spring 45 Connecting rod 47 Arc Section 48 Straight Rod Sections 51 driven shaft 53 U-shaped bush 64 Void Space 65 Void Space 66 Void Space 71 Contact Line 72 Contact Line 81 narrow section 82-step section 83 wide section A-axis

Claims

1. A coupling device (1) for connecting a drive shaft (31) of an actuator (3) to a driven shaft (51) of an exhaust gas valve (5), said coupling device (1) defining an axis of rotation (A) and comprising: a torsionally stiff retainer (2) having an axially extending slot (25); a connecting rod (45) received in said slot (25) for translational movement relative to said holding part (2) in the direction of said axis of rotation (A); an elastic element (4) biasing the connecting rod (45) in the direction of the rotation axis (A) and having an attachment section (42) fixed to the holding part (2); The holding portion (2) and the connecting rod (45) are connected to each other in a non-rotatable manner, the opposing edges of the slots (25) are spaced from each other by a distance that essentially corresponds to the outer width diameter of the connecting rods, so that the connecting rods (45) have no rotational play in the corresponding slots (25); A coupling device, wherein said elastic element (4) comprises a conical coil spring (43).

2. 2. The coupling device according to claim 1, wherein the slots (25) have edges (27) that face each other and extend parallel to the axis of rotation (A) of the coupling device (1) to guide the connecting rod (45) translationally and to transmit torque from the connecting rod (45) to the holding part (2).

3. 3. A coupling device according to claim 2, wherein the edges (27) are opposite each other in the circumferential direction relative to the axis of rotation (A) of the coupling device (1).

4. 2. The coupling device of claim 1, wherein the conical coil spring (43) has a narrow end fixed to the connecting rod (45) and / or a wide end fixed to the mounting section (42).

5. Coupling device according to one of the preceding claims, wherein the elastic element (4) and the connecting rod (45) are integrally formed.

6. Coupling device according to one of the preceding claims, wherein the elastic element (4) and the connecting rod (45) are integrally formed in a thread-like shape.

7. Coupling device according to one of the preceding claims, wherein the elastic element (4) and the connecting rod (45) are integrally formed as a thread-like shape of constant diameter.

8. The holding portion has a central section (20) and two bent portions (23a, 23b, 23c) bent in a first direction relative to the central section (20), Coupling device according to one of the preceding claims, wherein the bent portions (23a, 23b, 23c) form slots (25) for holding the connecting rods (45).

9. A coupling device (1) for connecting a drive shaft (31) of an actuator (3) to a driven shaft (51) of an exhaust gas valve (5), the coupling device (1) defining an axis of rotation (A) and comprising: a torsionally stiff retainer (2) having an axially extending slot (25); a connecting rod (45) received in said slot (25) for translational movement relative to said holding part (2) in the direction of said axis of rotation (A); an elastic element (4) biasing the connecting rod (45) in the direction of the rotation axis (A) and having an attachment section (42) fixed to the holding part (2); The holding portion (2) and the connecting rod (45) are connected to each other in a non-rotatable manner, the opposing edges of the slots (25) are spaced from each other by a distance that essentially corresponds to the outer width diameter of the connecting rods, so that the connecting rods (45) have no rotational play in the corresponding slots (25); The holding portion has a central section (20) and two seams (22b, 22c) bent in a second direction relative to the central section (20); The joints (22b, 22c) form at least one recess (24, 24') for retaining the mounting section (42).

10. The holding portion (2) has a central plate section (20) between the bent portions (23a, 23c), The central plate section (20) connects to the mounting section (42).

9. The coupling device of claim 8.

11. 11. The coupling device according to claim 10, wherein the holding portion comprises a sheet metal part having the central plate section (20) and, optionally, two of the bent portions (23, 23b, 23c) and / or two seams (22a, 22c).

12. 6. A coupling device according to claim 1 or 5, wherein the retaining portion comprises a hollow cylindrical body (28, 29).

13. 13. A coupling device according to claim 1, 5 or 12, wherein the retaining portion comprises a cylindrical body (29) with a constant diameter or a cylindrical body (28) with a stepped diameter comprising at least a narrow section including a recess (24) and a wide section including a slot (25).

14. Coupling device according to one of the preceding claims, wherein the holding part (2) comprises at least one void space (64, 65, 66) or a plurality of void spaces (64, 65, 66) extending along the direction of the rotation axis (A).

15. 15. The coupling device according to claim 1, wherein the holding portion (2) comprises at least one void space (64, 65, 66) or a plurality of void spaces (64, 65, 66) extending along the direction of the rotation axis (A) between cylindrical body sections of the hollow cylindrical body (28, 29) or between adjacent folds (23a, 23b, 23c) and / or seams (22b, 22c).

16. 16. A valve system (7) comprising an actuator (3) having a drive shaft (31), an exhaust gas valve (5) having a driven shaft (51), and a coupling device (1) according to one of claims 1 to 15, which connects the driven shaft (51) to the drive shaft (31) non-rotatably with an axial clearance.

17. 17. The valve system (7) according to claim 16, wherein the mounting section (42) or a section of the holder (2) fixed to the mounting section (42) connects to the drive shaft (31).

18. The valve system (7) further comprises an adapter (53a, 53b) for form-fittingly engaging the drive shaft (31) or the driven shaft (51); 18. The valve system (7) according to claim 16 or 17, wherein the adapter surrounds the mounting section (42).

19. The valve system (7) according to one of claims 16 to 18, wherein the drive shaft (31) and / or the driven shaft (51) realize one or two respective contact lines (71, 72) with corresponding engagement portions of the coupling device.

20. The valve system (7) according to one of claims 16 to 19, wherein the drive shaft (31) and / or the driven shaft (51) realize one or two respective contact lines (71, 72) with the connecting rod (45) of the coupling device, with the mounting section (42) or with a section of the holder (2) fixed to the mounting section (42).

21. Valve system (7) according to one of claims 16 to 20, wherein torque is transmitted from the drive shaft (31) to the driven shaft (51) via the rigid retainer (2).

22. Valve system (7) according to one of claims 16 to 21, wherein torque is transmitted from the drive shaft (31) to the driven shaft (51) exclusively via the rigid retainer (2).

23. 23. A valve system (7) according to claim 21 or 22, wherein the elastic element (4) remains free from torque.

24. Valve system (7) according to one of claims 21 to 23, wherein the elastic element (4) is under tension or is free from tension in the direction of the axis of rotation (A).

25. The valve system (7) according to one of claims 16 to 24, wherein the coupling device (1) connects the driven shaft (51) to the drive shaft (31) with an axial clearance but no rotational clearance.

26. a) providing a retaining part (2) comprising a slot (25) and recesses (24, 24'); b) providing a coil spring (41, 43) comprising a connecting rod (45) and a mounting section (42); c) fitting said connecting rod (45) into said slot (25) of said holding part (2); d) fitting the mounting section (42) into the recess (24, 24') of the holding part (2); A method for assembling a coupling device (1) according to one of claims 1 to 15, comprising:

27. 27. The method according to claim 26, wherein between steps c) and d) the holding part (2) is rotated within the coil spring (41, 45).

28. - before, during and / or after said rotation, said holding part is translated at least once along its axis (A), along said mounting section (42) or along said connecting rod (45); 28. The method of claim 27.

29. 26. A method for assembling a valve system (7) according to one of claims 16 to 25, wherein the elastic element (4) is compressed in the axial direction (A) when attaching the coupling device (1) to the actuator (3) and the exhaust gas valve (5).

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