Cardan shaft

Abstract

Connecting arrangement for connecting two parts (1, 5) by means of two connected sockets (2, 4), wherein parts and sockets have rotationally symmetrical engagement regions around engagement axes (11, 15 or 12, 14) which do not extend over 180° and which are complementary between a respective part and a socket, characterized in that a respective socket is screwed into a respective part and the complementary engagement regions hold the part on its socket so as to be pivotable about the respective aligned engagement axes and, overall, tensile-resistant in the direction of a zenith axis of the parts (10 or 16), and in that the sockets (2, 4), after the part-socket pairs have been screwed in and positioned relative to one another, are connected to one another so as to be rotationally resistant around the zenith axes (10, 16) and tensile-resistant in their direction.

Description

[0001] Technical field: Joints, couplings and connecting arrangements The invention shows a buildable connecting arrangement for connecting two parts with large area moments of inertia, such as those required by drives as a joint with angle compensation, and a cardan shaft built therewith. State of the art

[0002] There are many different couplings and joints for connecting two parts.

[0003] Universal joints transmit torque from shaft ends at an angle to one another with yokes via a journal cross. The journals are bent towards the central intersection area, via which the force is transferred to the output journal-yoke pairing. This results in high loads in the attachment area of ​​the journals at the intersection. Installing the journal cross in the yokes requires space for threading into the bearing eye and slip-on bushings or split bearing eyes. Only for simple requirements can thin and therefore flexible tubes with bearing eyes be elastically slipped over the journals. The cardan error is compensated for by a universal shaft in a W or Z arrangement to the driving and output ends, but the oscillatingly accelerated intermediate piece remains critical and requires, among other things, a low specific mass.

[0004] Rzeppa (ball) constant velocity joints transmit forces without cardan shaft error, but require a radial dimension several times larger than the diameter of the driving shaft. Balls transmit the load under shear stress.

[0005] WO 2011 / 117 412 A1 discloses bearings that can be assembled even for high tensile forces. EP 2 408 985 A1 shows a design for machine assemblies whose multi-part components engage with each other by twisting around their connecting line. Similar connection arrangements are shown in US 2 841 968 A, US 1 388 225 A, and US 1 298 785 A.

[0006] The invention aims to provide a high-performance, easily constructed connecting assembly with angle compensation and application as a built-up cardan shaft. This object is achieved by the features specified in claim 1.

[0007] The invention further aims to provide a high-performance connecting arrangement for two parts. This objective is achieved by the features specified in claim 10. Description

[0008] An angle-compensating joint essentially combines a pivoting movement from the connecting axis with the torsionally and tensile-resistant connection of the input and output sides around the connecting axis. According to the invention, the two crossed pivot axes of the universal joint are implemented separately for each side. Rotationally symmetrical and positively complementary engagements located on the inner or outer surface of sockets or spherical half-shells, which pivotally hold the socket on the complementary saddle, distribute the forces over large radii and across large surfaces. Each side represents a self-contained pivot joint.

[0009] The engagements undercut each side in the cylindrical circumferential and axial directions, thus withstanding both torques and tensile forces. They also optionally and advantageously undercut in the radial direction of the ball from the joint center. This prevents the part to be joined from expanding and lifting from its socket directly in the joint, whereas this is conventionally prevented by a stiffer and thus thicker body of the bearing eyes.

[0010] The rigid connection between both sides can be achieved conventionally or, advantageously for assembly and coupling, using a locking bar with the same engagements as those for the pivoting movement. Collisions between the two parts during the pivoting movement are prevented by clearances. In extreme cases, a built-in, rotationally fixed connection arrangement without clearance and thus without pivoting range is also possible as a coupling.

[0011] To facilitate assembly, all parts engagements are designed as a sector of maximum 180°.

[0012] This advantageously avoids central elements in the joint, and also prevents overlap during the pivoting movement from the driving side to the driven side. The advantageous form-fitting via a large number of small grooves also reduces peak stresses. Each of these advantages independently leads to a slimmer and lighter design. The invention is illustrated and described in more detail below using figures. Fig. 1 shows a connecting arrangement according to the invention. Fig. 2 shows the middle pans to Fig. 1 enlarged. Fig. 3 shows an application of the connection arrangement according to Fig. 1. Fig. 4 shows the assembly of the connection arrangement according to Fig. 1. Fig. 5 shows an adjustment device for a coupling connection arrangement. Fig. 6 shows a further advantageous embodiment of the middle pan. Fig. 7 shows a closed bellows for one side of the connection arrangement, Fig. 8 shows another version of the connection arrangement.

[0013] The overview in Fig. Figure 1 shows an exploded view (1a) of a connecting arrangement 20 according to the invention, except for the latch 3, as well as its side view (1b), and views of the assembled connecting arrangement from above (1c) and from the side (1d). The individual parts are continuously assigned engagement axes (11 to 1, 12.1 and 12.2 to 2, 13 to 3, 14.1 and 14.2 to 4, 15 to 5) as a symmetry axis for each engagement area - inside and outside with sub-points 1 and 2. The outer parts 15 are the parts to be connected. They have free spaces 18 ( Fig. 1b,c) and can thus be pivoted on their pans 24 and thus tilt their zenith axes 10 and 16 against each other. Each half-shell or shell sector is analogously assigned a zenith axis that runs from the center through the surface center of the shell sector. The engagement axes of a position are perpendicular to the zenith axis. Fig. 3 shows such a tilting relative to the main axis 60 of the connecting arrangement using the example of a cardan shaft. Fig. Figure 2 shows examples of the inner and outer engagement areas 22.1 and 22.2, or 24.1 and 24.2, and their axes 12.1 and 12.2, or 14.1 and 14.2 for the cups 2 and 4, respectively. In the other figures, the explicit designation of the engagement areas is omitted for clarity, and only the engagement axes are indicated. The engagement areas on both sides of the shell can have skewed engagement axes. Fig. 1 and Fig. 2, the engagement axes 14.1 and 14.2 of the socket 4 intersect vertically at the center of its envelope sphere.

[0014] Even at full deflection, parts 1, 5 remain on their sides or sockets due to the clearances 18. Interlocking beyond the pivot axis, as conventionally occurs with fork eyes and pins in any position, is advantageously avoided. Thus, with a suitable locking mechanism, the connection arrangement 20 can be separated even in the pivoted state, and intermediate pieces in a series of connections, e.g., the center section of a cardan shaft, can be radially disassembled or unassembled without having to remove or move the outer parts. This will be discussed in more detail below.

[0015] To absorb torque, parts 1, 5 and sockets 2, 4, and optionally sockets and advantageously lock 3, each engage with each other via complementary tongue and groove pairs. The engagement areas are rotationally symmetrical about their engagement axes 11 to 15, thus allowing the parts to be rotated around them in pairs as a half-shell system with inner and outer shells and aligned engagement axes; when screwed in, they form a hemispherical stack. In the direction of the zenith axis, the grooves can form undercuts near the poles, so that they absorb tensile forces in the direction of their zenith axes and hold the interlocking pairs of parts together. The grooves can therefore be designed as rotationally symmetrical splines.

[0016] The figures show the sockets 2, 4 advantageously connected via a latch 3 with similar engagements as between the parts and their sockets (1 with 2 and 4 with 5) for detachable coupling. The sockets 2 and 4 can, however, also be connected in a conventional detachable or permanent manner after being screwed into the parts 1, 5 to be connected. Forces are only transferred between the sides via the connection of the sockets 2, 4, which results in specifically larger area moments of inertia for the acting surfaces compared to the conventional fork-pin (cross) pairing. In addition, the damping can advantageously be adjusted via the connection, advantageously via the latch 3, decoupled from the guide. The latch, for example, can be designed as a damping elastomer, and the engagement areas of the socket-part pairing can be provided with suitable sliding pairs made of hardened metal or plastic.

[0017] In a further advantageous embodiment, the grooves can have radially undercut profiles to better stiffen the half-shells, allowing them to absorb radial forces at all spatial angles, even from the center of the joint. This can prevent spherically symmetrical radial gaping or local or complete lifting due to different thermal expansions of the shells. Fig. 2 shows, in an isometric view and in the view into the sockets, grooves with additional undercut, dovetail-like profiles 21 in the enlargement of the sockets 24 together with the different engagement axes 12.1, 12.2 and 14.1, 14.2 to their inner and outer engagement areas 22.1, 22.2 and 24.1, 24.2, respectively. The profiles 21 for the grooves are regularly distributed on a pitch circle.

[0018] Parts 1 and 5 have grooves 11 and 15 respectively, running around their engagement axes. Their inner grooves engage in complementary grooves on the outside of the associated socket 2 and 4, as is also the case Fig. 4g and Fig. 4h shows.

[0019] Parts 1 and 5 can have a matching body that integrates the shown engagement areas as a connection. Both parts 1 and 5 can have different clearances or engagements. Fig. Figures 3a and b show a universal joint in known W and Z configurations with two integrated connections 20 as a universal joint. Parts 1 and 5 are integrated into the shaft sections and designated 1a and 5a and 5b, respectively. Since parts 1 and 5 are identical here, the order of designation is arbitrary. The advantageous slim design with its very small interference contour is clearly evident.

[0020] The sequence of assembly of the connecting arrangement 20 according to the invention according to Fig. 1 shows Fig. 4. For a better overview, the intervention areas are shown in the sections of the Fig. 4a to 4f not shown, but in Fig. 4g and Fig. 4h is shown in an isometric view of the selected parts. In 4a to 4c, socket 4 is positioned opposite part 5 and screwed into the complementary engagement areas. The latch 3 has also been screwed into the socket 4 beforehand and now rotates with it. In 4d, the similarly assembled shell stack of part 1 and socket 2 is positioned congruently with the inner engagement areas opposite the fully screwed-in stack from 1c. Socket 2 has the same engagements on its inner side as socket 4 and thus allows the latch 3 to be accommodated in the same way as in Fig. 2 shown. Fig. Figure 1e shows the bar 3 rotated back 90° after the stack pairs have been placed together, engaging and connecting both sides. The outer cups 2 4 and parts 1 5 do not directly engage with the other side. Contact can even be prevented by appropriate spacing, which can facilitate tilting during radial positioning. The cups can be spherical. The bar 3 can also be designed as a section of the hemisphere, e.g., as a spherical cap.

[0021] The bolt 3 can be supplemented with a second bolt 3', which then engages in the socket 2 like the first one in socket 4, to form a full ball. Then, after positioning, turn accordingly Fig. 4d both bars overlap each other into the opposite pan and clamps in the working position with double surface ( Fig. 1f and Fig. 1h). In addition, imbalances can be easily avoided. Fig. 1g and Fig. 1h shows closed connections with hidden positions of part 1 and pan 2.

[0022] An adjustment and holding device can be used to rotate and fix the bolt when placed together. Fig. Figure 5 shows the closing bolt 3 with a multi-part adjustment and holding device 40 consisting of a Bowden cable 40.1 with a retainer 40.2 and an actuator 40.3. When screwed into the socket 4, the bolt can engage the retainer that has just been inserted at point 41. The adjustment can also be carried out using a cable pull for each direction of rotation, similar to the Bowden cable, or via a wheel, rubbing or meshing at point 41. Fixing can also be conventionally achieved using elastic springs or pawls between the bolt and socket. It is advantageous to lead access to the bolt 3 through the outer sockets 4 or part 5 in the zenith axis of the socket, so that only a slight weakening of the force-transmitting surfaces occurs. Outside the connecting arrangement, the actuator 40.3 can be led outwards in a non-critical area. Access through part 5 must take the pivoting relative to the socket into account by providing appropriate clearances.This means that it is possible to open it even when it is pivoted.

[0023] Since the pan 4 does not pivot relative to the bolt 3 during operation, the weakening of the outer part 5 can be kept small in certain applications by allowing access to the adjustment device 40 only when the zenith axis 16 of part 5 is in the non-pivoted orientation. This avoids the need for additional clearances in part 5.

[0024] As already mentioned, parts 1 and 5 can advantageously be designed identically to reduce the number of individual parts. This defines the outer engagements of the sockets 2 and 4, while the inner engagements can be identical for the latch 3. In a further embodiment, the engagement axes 12.1, 12.2 of the socket 2 are not designed to be rotated by zero degrees and the engagement axes 14.1, 14.2 of the socket 4 are not designed to be rotated by 90°, as previously shown, but rather rotated by 45° in the opposite direction ( Fig. 6a). Since the pans are rotated by 180° to each other in the connection arrangement, the outer axis 12.2 folds over to the axis 14.2 with an identical design of the pans 2 and 4, as shown in Fig. Figure 6b shows a simplified rear view of the axes without pan 4, and in parentheses, the axis 12.2 of the pan 2 not folded over. They (12.2 and 14.2) then intersect at 90° as before, while the inner axes 12.1 and 14.1 are aligned, and the locking bar 3 can connect the pans 2 and 4. The entire connection arrangement thus advantageously consists of only two or—with an optional locking bar—three individual parts.

[0025] All parts or positions represent sectoral rotational bodies up to a maximum of 180°, particularly in their engagement areas, and can be manufactured, machined, and handled in the direction of rotation without undercuts. The parts can be cast and demolded by rotating, or the mold can be released by rotating for each engagement area. The process essentially corresponds to disassembly, whereby, for example, the pan 4 is Fig. 1 and Fig. 2 between the bolt 3 and part 1, the bolt is then rotated around its engagement axis 13—which corresponds to the generated engagement axis 14.1—and then the socket is rotated around the engagement axis of part 5, which, due to the molding, corresponds to its engagement axis 14.2. This allows individual or all parts of the connecting assembly or the drive shaft to be advantageously manufactured cost-effectively in optionally fiber-reinforced plastic, injection-moldable ceramics, or other composite materials, including castable renewable raw materials.

[0026] All pans 2, 4 and bars 3 3' can also be advantageously made from smaller sectors and placed together to form the final sector.

[0027] Since the effective surfaces advantageously lie substantially outside the main axis 60 of the connecting arrangement, the connecting arrangement can be designed in a tube-like manner as a hollow connecting arrangement and, after assembly, for example in a hollow cardan shaft, can receive installations for example compressed air, oil, data, energy, inspection devices or cooling protected centrally rotating or stationary.

[0028] Since the pivoting movement advantageously does not interfere with the other side, the joint has three separate areas, consisting of i) part 1 with socket 2 on the outside, ii) socket 2 on the inside (with latch 3 and optional 3' and) with socket 4 on the inside and iii) socket 4 on the outside with part 5. This allows protective bellows and seals to be installed on one side in such a way that separating the connection does not damage or open it. The bellows or seals only have to enable the pivoting movement between the socket and part of one side. This means that lubrication or pressure areas in the area of ​​the joints can be kept closed and sealed even when open. Lubricants cannot leak out. Fig. Figure 7 shows a simplified bellows 50 which seals against the socket 2 and surrounds the part 1, in open (7a) and closed connection (7b), without disturbing the space of the bolt 3.

[0029] The middle section (point ii above) advantageously encapsulates the bars during use to protect them from dirt and moisture. A simple ring seal between the pans is sufficient.

[0030] An advantageous application of the encapsulated halves is hygienic separation or gas- or fluid-tight locks. The advantage here is the good cleaning possibility of the dismantable connection arrangement and its simple assembly even from the radial direction when pivoted.

[0031] Fig. Figure 8 shows an embodiment of the connecting arrangement, where the bolts 3, 3' each have a cylindrical stump 3.1, 3.1' extending outwards, which is rotatably guided through free spaces in the other parts and which can serve i) for locking as well as ii) as an independent connection to a third direction or iii) as a third or fourth connected part. Fig. 8a) hold all parts together, in Fig.8b) the front side is also fully occupied.

Claims

[1] Connecting arrangement for connecting two parts (1, 5) by means of two connected sockets (2, 4), wherein parts and sockets have rotationally symmetrical engagement areas around engagement axes (11, 15 or 12, 14) which do not exceed 180° and which are complementary between each part and a socket, characterized by that one socket is screwed into each part and the complementary engagement areas hold the part on its socket so that it can pivot about the respective aligned engagement axes and, as a whole, tensile-resistant in the direction of a zenith axis of the parts (10 or 16), and that the sockets (2, 4) are connected to one another so that they can rotate about the zenith axes (10, 16) and are tensile-resistant in their direction after the part-socket pairs have been screwed in and positioned relative to one another. [2] Connecting arrangement according to claim 1 characterized bythat the connection of the sockets is effected by means of a bolt (3) which has a rotationally symmetrical engagement region (23) around an engagement axis (13), and that the sockets (2, 4) have on their inner side a further engagement region (22 or 24) around engagement axes (12.2 and 14.2), which is complementary to the engagement region (23) of the bolt, and that the engagement axes of the sockets and those of the bolt are aligned, and that the bolt (3) is completely screwed into a socket before positioning, and after positioning clamps both sockets by rotating about its engagement axis 13. [3] Connecting arrangement according to claim 2, with a further bolt (3') characterized by that the further bar (3') has identically profiled engagement areas as bar (3) and engages in the free socket (2) before positioning and clamps both sockets (2,4) together with the first bar (3) after rotation. [4] Connecting arrangement according to one of the preceding claims, characterized by that a part (1 or 5) and / or the pan (2 or 4) and / or the bar (3) is made up of several parts. [5] Connecting arrangement according to one of the preceding claims, characterized by that the engagement axes (12 and 14) of the cups (2, 4) are rotated by 90° relative to each other around their zenith axes. [6] Clutch, characterized by that it has a connecting arrangement according to one of the preceding claims and that the bolt (3) can be rotated about its engagement axis (13) via an adjusting device (40) for coupling the pans. [7] Cardan shaft with two angle-compensating joints characterized by that at least one of its joints is formed by a connecting arrangement according to one of claims 1 to 5. [8] Cardan shaft according to claim 7 characterized by that it is hollow around its central axis. [9] Cardan shaft according to claim 7 or 8 characterized bythat its intermediate piece has no direct connection with the driving or output shaft that pivots during operation. [10] Connecting arrangement for connecting a first component (1) to a second component (3) by means of a connecting socket (2), wherein components (1, 3) and the socket (2) have rotationally symmetrical engagement areas around engagement axes (11, 13 or 12.1, 12.2) which do not extend over 180° and which are complementary between the components and the facing socket side, characterized by that the socket (2) engages on the inside in the second component (3) and on the outside in the first component (1), and the complementary engagement areas hold the components (1, 3) on the socket (2) pivotably about the respective aligned engagement axes and overall in the direction of a zenith axis (10) in a tensile-resistant manner and non-rotatably about it.

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