COUPLING

Description

[0001] The invention relates to a coupling with at least one first coupling element, at least one second coupling element, a plurality of connecting pieces, and a plurality of elastic joint bushings, wherein for connecting the coupling elements at least one connecting piece and at least one joint bushing are arranged one behind the other between the coupling elements, so that at least one joint bushing forms an elastic composite bearing element between the connecting piece and at least one coupling element.

[0002] Such a coupling is known, for example, from DE 42 05 666 C2 and is used in drive technology as a compensating coupling, which connects two shafts in a torsionally rigid and offset-compensating manner. In addition to transmitting torque, these couplings also compensate for axial, radial, and angular misalignments, as well as for misalignments between the two shafts connected via the coupling elements. The coupling described in DE 42 05 666 C2 has the disadvantage that any displacement of the coupling elements relative to one another results in purely elastic deformation of the joint bushings, which are held non-rotatably in the connecting pieces.

[0003] This limits the displacement of the coupling elements, and the magnitude of the angular displacement places considerable stress on the joint bushings, which disproportionately shortens their service life, as the joint bushings are subjected to dynamically changing loads with each rotation of the coupling. Thus, elastic joint bushings exhibit a disproportionately rapid decrease in service life when a certain angular displacement value is exceeded.

[0004] DE 195 15 101 C1 discloses a coupling with elastic plates. It also discloses joint bushings in the form of sleeves in which a rubber body is arranged. The rubber body serves to compensate for manufacturing tolerances during assembly, in which threaded bolts are inserted into the sleeves. Elastic deformation of the joint bushing described therein when the coupling elements are displaced relative to one another is not disclosed.

[0005] DE 27 52 445 A1 discloses webbing loops as connecting elements that are largely rigid. This prevents improved elasticity.

[0006] FR 745 135 A discloses connecting rods mounted in elastic joint bushings.

[0007] JP S63 57923 A discloses a coupling with a multi-layer body that is designed to be flexible as a whole. The coupling elements are vulcanized to the body.

[0008] EP 0 035 283 A1 discloses a coupling with elastic joint bushings, which are each coupled to a link to connect the coupling elements, so that the joint bushings form an elastic composite bearing element between the link and a coupling element. Actual deformation of the link is neither described nor intended here.

[0009] It is therefore an object of the invention to provide an improved coupling which offers a longer service life of the components and enables a greater displacement of the coupling elements relative to one another.

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

[0011] The coupling according to the invention is characterized in that the connecting piece is a flexibly elastic plate, wherein the joint bushing and the plate are designed such that any displacement of the two coupling elements relative to one another is absorbed by the plate and the joint bushing. Because the connecting piece is a flexibly elastic plate and any displacement of the two coupling elements relative to one another is distributed between elastic deformations of the plate and the joint bushing, the service life of the coupling components can be extended even in the event of large displacements of the coupling elements relative to one another, since the joint bushings are subjected to less stress by the displacement. Distributing the compensation of the displacement movement between the joint bushing and the flexibly elastic plate reduces the load on the joint bushings, since the plates facilitate part of the displacement.The elastic bending of the plates when the coupling elements are displaced leads to less elastic deformation of the joint bushings, which disproportionately increases the service life of these components. Since the flexible plates also contribute to the displacement, the angle at which dynamic loading of the joint bushings occurs is reduced, which extends the possible service life of the joint bushings under dynamically changing loads due to angular displacement. This increases the service life while simultaneously improving the ability to accommodate displacement. By distributing the angular displacement between the two components connected in series—the flexible joint bushing and the flexible plate—the stress on each individual component can be significantly reduced, thus significantly increasing the service life.

[0012] Advantageous embodiments and further developments of the invention emerge from the dependent claims. It should be noted that the features listed individually in the claims can also be combined with one another in any technologically expedient manner, thus revealing further embodiments of the invention.

[0013] According to an advantageous embodiment of the invention, at least two plates and at least two joint bushings are arranged one behind the other in the circumferential direction at predetermined angular intervals relative to a center axis of the coupling between the coupling elements. By arranging several plate and joint bushing combinations in the circumferential direction at predetermined angular intervals relative to a center axis of the coupling, the loads during the transmission of larger torques can be distributed among several component combinations, so that the bushings and plates connected in series are supported by parallel combinations.

[0014] A particularly preferred embodiment provides for a joint bushing to be arranged between each link plate and each coupling element. Preferably, at least one joint bushing forms an elastic composite bearing element between the connecting piece and each coupling element. In this case, the joint bushings form the connection between the links and the coupling elements. This allows any angular displacement of the coupling elements relative to one another to be compensated for jointly via the links and the connecting joint bushings. For this purpose, the links are each coupled to the coupling elements at their ends with an elastic joint bushing, so that the displacement is distributed between the flexurally elastic link plate and the two elastic joint bushings coupled one behind the other with it.

[0015] A particularly advantageous embodiment of the invention involves arranging several plates between the joint bushings. This allows for the use of several thinner and thus more flexible plates in parallel, instead of relatively thick and rigid plates. This allows the flexibility of the structure to be further increased while maintaining the same torque capacity, thus minimizing reaction forces.

[0016] A particularly advantageous embodiment of the invention provides for the joint bushing to be spherical, conical, or cylindrical in shape. The joint bushing can be designed as a rubber bushing. In these rubber bushings, a rubber part is usually held in a materially bonded manner in preferably metallic bearing sleeves. This results in a play-free design for the joint bushings. Due to this design, the joint bushings are maintenance-free, as there is no tribological system in the joint bushing with sliding relative movement and Coulomb friction, which usually requires regular maintenance through lubrication and is also subject to sliding wear. In addition, the rubberized connection of the bearing sleeves through the rubber part arranged between them leads to acoustic decoupling between the bearing sleeves of the joint bushing and thus advantageously also to acoustic decoupling between the coupling elements of the coupling.Advantageously, the bearing sleeves and the rubber part bonded between them have a spherical, conical, or cylindrical shape. The shape of the joint bushing can be spherical, conical, or cylindrical, allowing the load caused by displacement to be distributed among the plates in a way that is specific to the application. The joint bushing, designed as a rubber bushing, absorbs the displacement of the two coupling elements relative to each other together with the plate through deformation of the rubber part between the bearing sleeves of the joint bushing.

[0017] In a preferred embodiment, the joint bushing is designed as a spherical elastomer bushing. This allows the displacement to be distributed particularly well between the joint bushings and the flexible plate.

[0018] Furthermore, in an advantageous embodiment, the joint bushing can form an elastic, preferably rubber-elastic, joint. Such an elastic joint makes it particularly easy to distribute the displacement between the joint bushings and the flexible, elastic tab.

[0019] An advantageous embodiment of the invention provides for the joint bushing to be integrated into a connecting bushing of the bracket. By integrating the internal joint bushing into the connecting bushing of the bracket, a space-saving design can be realized, with fewer forces requiring redirection.

[0020] A particularly advantageous embodiment provides for the joint bushing to be connected to a connecting bushing of the bracket via a pin-shaped connection. The forces between the external joint bushing and the bracket are transmitted via the pin-shaped connection. The pin-shaped connection allows for a separate arrangement of the joint bushing and the bracket, which facilitates the replacement of individual components.

[0021] An advantageous embodiment provides for the link to be made of spring steel, plastic, fiber-reinforced plastic, or as a textile-reinforced and / or thread-reinforced elastomer link. By varying the material and geometry of the link, the longitudinal stiffness of the connecting piece can be adjusted. The transverse stiffness of the connecting piece, i.e., the angular stiffness, can also be adapted to the application by selecting the material and geometry of the link. The length of a link can be between 100 and 300 mm, with the length-to-thickness ratio being between 10:1 and 3:1. A length-to-thickness ratio of 3:1 is very easily achieved with textile-reinforced and / or thread-reinforced elastomer links. Larger length-to-thickness ratios are possible for links made of spring steel, plastic, or fiber-reinforced plastic.

[0022] According to a preferred embodiment of the invention, the displacement of the two coupling elements relative to one another is distributed essentially equally between the plate and the joint bushing. This means that the bending angles of the plate and the joint bushing resulting from a displacement are almost identical, or at least of a similar magnitude (e.g., the ratio of the bending angles of the plate and the joint bushing is between 0.5 and 2). As a result, the axial stiffness of the coupling is determined approximately equally by the angular displacement of the bushing and the deformation of the plate. The angular stiffness can be adjusted by varying the materials and geometries of the plates and joint bushings.

[0023] The distribution of the relative displacement of the two coupling elements between the plates and the joint bushings can also be optimized with regard to service life. The design is such that the plates and the joint bushings of the coupling ideally fail simultaneously, thus maximizing the overall service life of the coupling components. This distribution prevents premature failure of the flexible plates or the flexible joint bushings, thus optimizing the overall service life of the coupling by coordinating the components to distribute the relative displacement of the two coupling elements.

[0024] Further features, details, and advantages of the invention will become apparent from the following description and from the drawings, which show exemplary embodiments of the invention. Corresponding objects or elements are provided with the same reference numerals in all figures. They show: Figure 1: coupling according to the invention, Figure 2: detailed view, Figure 3: top view and Figures 4, 5, 6: displacement states.

[0025] In the Figure 1Denoted by the reference numeral 1, a coupling according to the invention is shown. The coupling 1 comprises a first coupling element 2, which can be assigned to the drive, for example, and is coupled to a drive shaft. The coupling 1 also comprises a second coupling element 3, which can be coupled to a shaft of the output. Between the coupling elements 2, 3 of the coupling 1, several connecting pieces 4 and several elastic joint bushings 5 ​​are arranged. To connect the coupling elements 2, 3, a first joint bushing 5, a connecting piece 4, and a second joint bushing 5 are arranged one behind the other between the coupling elements 2, 3. The joint bushings 5 ​​form elastic composite bearing elements between the connecting piece 4 and the two coupling elements 2, 3 connected via it. The connecting piece 4 is advantageously designed as a flexurally elastic, i.e., flexible, tab 4.As a result, any (axial and / or angular) displacement of the two coupling elements 2, 3 relative to one another is distributed between the plate 4 and the coupled joint bushings 5. This significantly extends the service life of the coupling components 4, 5, even in the case of large displacements of the coupling elements 2, 3 relative to one another, since the joint bushings 5 ​​are subjected to less stress by the displacement. Distributing the displacement movement between the joint bushings 5 ​​and the flexurally elastic plate 4 reduces the load on the joint bushings 5, since the plates 4 allow part of the displacement movement. The elastic bending of the plates 4 during the displacement of the coupling elements 2, 3 can achieve a lower elastic deformation of the joint bushings 5, which disproportionately increases the service life of these components 5.The contribution of the flexurally elastic plates 4 to the displacement of the coupling elements 2, 3 reduces the angle at which dynamic loading of the joint bushings 5 ​​occurs, thereby increasing the achievable service life until the joint bushings 5 ​​need to be replaced. In addition, the displacement capability of the coupling 1 can be increased via the flexurally elastic plates 4. Distributing the angular displacement between the two series-connected elastic joint bushings 5 ​​and the flexurally elastic plate 4 significantly reduces the stress on each individual component 4, 5, so that the service life can be significantly increased. As can be seen, in the exemplary embodiment, three plates 4 with a total of six joint bushings 5 ​​are arranged one behind the other in the circumferential direction at predetermined angular intervals with respect to the central axis 6 of the coupling 1 between the coupling elements 2, 3.These three plates 4 transmit the torque between the first coupling element 2 and the second coupling element 3, whereby the plates 4 together with the joint bushings 5 ​​divide the displacement of the coupling elements 2, 3 relative to one another and the offset (see . Figures 4 to 6) together. With the shown arrangement of the plates 4 and the joint bushings 5 ​​in the circumferential direction with respect to the central axis 6 one behind the other between the star-shaped coupling elements 2, 3, a compact compensating coupling 1 can be realized. When rotated about the central axis 6, the coupling elements 2, 3 transmit a torque via the operative connection with the flexible plates 4, which for this purpose transmit tensile forces in the circumferential direction about the central axis 6. In order to enable the greatest possible displacement, a joint bushing 5 should be arranged between a plate 4 and a coupling element 2, 3. The joint bushings 5 ​​each form the connection between the plates 4 and the two coupling elements 2, 3. The plates 4 are each coupled to the coupling elements 2, 3 at their ends with an elastic joint bushing 5.In the illustrated embodiment, the displacement of the two coupling elements 2, 3 relative to each other is therefore distributed between the flexible link 4 and the two elastic joint bushings 5 ​​coupled to it one behind the other. As shown in . Figure 1 As can be seen, the front joint bushing 5 is shown in section to allow a view into the interior of the joint bushing 5.

[0026] The Figure 2 shows a detailed view of the Figure 1 The sectioned area around the front joint bushing 5 shows the joint bushing 5 integrated into a connecting bushing 7 of the bracket 4. This saves space and ensures that forces do not need to be redirected as much. With the integration into the connecting bushing 7, commercially available rubber bushings can also be used as the joint bushing 5. Figure 2It can also be seen that the joint bushing 5 is spherically shaped. This allows the displacement to be distributed particularly well between the joint bushings 5 ​​and the flexurally elastic plate 4. In addition, the elastic joint bushing 5 contributes to the damping and torsional elasticity of the entire coupling 1. The permanently tolerable angular displacement capacity of the joint bushing 5 should be up to 1.5 degrees. The transient angular displacement capacity should also be above 1.5 degrees. The joint bushing 5 shown is designed as a rubber bushing. Here, a rubber part 9 is received in preferably metallic bearing sleeves 10, 11 in a material-to-metal bond. The rubber part 9 is preferably vulcanized onto the metallic bearing sleeves 10, 11. This achieves a play-free design for the joint bushings 5. The displacement of the bearing sleeves 10, 11 relative to each other occurs only via an elastic deformation of the rubber part 9 accommodated between the bearing sleeves 10, 11.The rubberized connection between the bearing sleeves 10, 11 by the rubber part 9 arranged therebetween also leads to an acoustic decoupling between the bearing sleeves 10, 11.

[0027] This also allows the coupling elements 2, 3 of the coupling 1 to be acoustically decoupled. As can be seen, the bearing sleeves 10, 11 and the rubber part 9 bonded between them have a spherical shape. With a rubber bushing, the angular stiffness of the elastic joint bushing 5 can be easily adjusted by varying the elastomer. Figures 1 and 2 A coupling 1 with tabs 4 made of spring steel or fiber-reinforced plastic is shown. The tabs 4 preferably have a flat body 8 between the connection sockets 7 arranged at the ends of the flat body.

[0028] The Figure 3 shows a plan view of a coupling 1, which corresponds to the coupling 1 according to the Figures 1 and2 corresponds, except that the tabs 4 here are designed as textile-reinforced and / or thread-reinforced elastomer tabs. Such textile-reinforced and / or thread-reinforced elastomer tabs 4 can be arranged particularly well next to one another, so that several tabs 4 can easily be arranged between the joint bushings 5.

[0029] In Figure 4, which shows a displacement of the two coupling elements 2, 3 relative to each other, it can be seen that two plates 4 are arranged between the joint bushings 5, which are placed around the connecting bushings 7, into which the joint bushings 5 ​​are integrated. In particular, the use of textile-reinforced and / or thread-reinforced elastomer plates 4 makes it easy to use several thinner and thus more flexible plates 4 in parallel, instead of relatively thick and rigid plates. In this way, the flexibility of the construction can be further increased while maintaining the same torque capacity, thus minimizing reaction forces. Both in Figure 4 as well as in the Figures 5 and 6 the two coupling elements 2, 3 are shown displaced relative to each other, so that both coupling elements 2, 3 form a plane extending from the central axis 6 ( Fig. 1) of the coupling 1 take on different orientations. The displacement of the two coupling elements 2, 3 relative to one another is distributed between the plates 4 and the joint bushings 5. In addition to the joint movement of the elastic joint bushings 5, it can be clearly seen that the flexurally elastic plates 4 between the coupling elements 2, 3 absorb a large part of the displacement. The permanently tolerable angular displacement capacity of the plates 4 should be up to three degrees, whereby the transient angular displacement capacity of the plates 4 should be more than three degrees. It is desirable that the displacement of the two coupling elements 2, 3 relative to one another is distributed equally between the plate 4 and the joint bushing 5. The axial stiffness of the coupling 1 is thus determined approximately equally from the angular displacement of the bushing 5 and the deformation of the plate 4.In this way, the angular stiffness can be adjusted by varying the materials and geometries of the plates 4 and joint bushings 5. In order to increase the service life of the coupling components 4, 5, the distribution of the displacement of the two coupling elements 2, 3 relative to one another should be optimized with regard to the individual service life of the plate 4 and the joint bushing 5. With a distribution that ensures that the plates 4 and the joint bushings 5 ​​of the coupling 1 ideally fail at the same time, the service life of the coupling components 4, 5 can be maximized overall. The distribution into definable portions thus prevents premature failure of the flexurally elastic plates 4 and the elastic joint bushings 5, so that the overall service life of the coupling 1 can be increased by coordinating the components 4, 5 to jointly distribute the displacement of the two coupling elements 2, 3 relative to one another.

[0030] In summary, the proposed torque-conducting coupling 1, particularly in the double-cardanic design, in which two couplings of the type shown in the figures are connected in series between the input and output via a shaft section, is particularly suitable for misalignment cases such as those that occur during shock loads, i.e., singular events with extreme misalignment values. The design exhibits low torsional elasticity and uniform torque transmission, which can be realized with plates 4 made of spring steel or plastic, but also with plates 4 made of fiber-reinforced plastic or textile-reinforced and / or thread-reinforced elastomer plates. Furthermore, the proposed coupling design 1 is backlash-free, which is a major advantage in the case of alternating loads.With the proposed designs, a coupling 1 can be realized with a compression spring stiffness (C / T ratio) of 40 to well over 100. The permanently tolerable angular displacement capability of the proposed coupling 1 is up to five degrees. The transient angular displacement capability of the coupling 1 can also be well over five degrees. List of reference symbols

[0031] 1 Clutch 2 First coupling element (input) 3 Second coupling element (output) 4 Link (connecting piece) 5 Joint bushing (rubber bushing) 6 Center axis 7 Connection bushing (link eye) 8 Flat body 9 Rubber part 10 Bearing sleeve (inner) 11 Bearing sleeve (outer)

Claims

1. Coupling (1) with - at least a first coupling element (2), - at least a second coupling element (3), - several connecting pieces (4), and - several elastic joint bushings (5), wherein at least one connecting piece (4) and at least one joint bushing (5) are arranged are arranged coupled one behind the other between the coupling elements (2, 3) in order to connect the coupling elements (2, 3), so that at least one joint bushing (5) forms an elastic composite bearing element between the connecting piece (4) and at least one coupling element (2, 3), characterized in that the connecting piece (4) is a bending elastic lug, wherein the joint bushing (5) and the lug (4) are designed such that a relocation of the two coupling elements (2, 3) in relation to one another is absorbed by the lug (4) and the joint bushing (5).

2. Coupling (1) according to claim 1, characterized in that at least two lugs (4) and at least two joint bushings (5) are arranged one behind the other in the circumferential direction at predetermined angular distances in relation to a central axis (6) of the coupling (1) between the coupling elements (2, 3).

3. Coupling (1) according to claim 1 or 2, characterized in that a respective joint bushing (5) is arranged between a lug (4) and a coupling element (2, 3).

4. Coupling (1) according to claim 3, characterized in that several lugs (4) are arranged between the joint bushings (5).

5. Coupling (1) according to any one of the preceding claims, characterized in that the joint bushing (5) is designed spherically shaped.

6. Coupling (1) according to any one claim 1 to 5, characterized in that the joint bushing (5) is designed as spherical elastomer bushing.

7. Coupling (1) according to any one of claims 1 to 6, characterized in that the joint bushing (5) forms an elastic, preferably rubber-elastic, joint.

8. Coupling (1) according to any one of the preceding claims, characterized in that the joint bushing (5) is integrated into a connection bushing (7) of the lug (4).

9. Coupling (1) according to any one of claims 1 to 7, characterized in that the joint bushing (5) is connected to a connection bushing (7) of the lug (4) via a pin-shaped connection.

10. Coupling (1) according to any one of the preceding claims, characterized in that the lug (4) is made of spring steel, plastic, fibre-reinforced plastic or as a textile-reinforced and / or thread-reinforced elastomer lug.

11. Coupling (1) according to any one of the preceding claims, characterized in that the relocation of the two coupling elements (2, 3) in relation to one another causes an elastic deformation of the lug (4) and the joint bushing (5).

12. Coupling (1) according to any one of the preceding claims, characterized in that the relocation of the two coupling elements (2, 3) in relation to one another is absorbed by the lug (4) and the joint bushing (5) in essentially equal parts.