DE102021132549A1 - Articulated joint, rotating unit and progressive cavity pump - Google Patents

Abstract

Articulated connection (1) within a rotating unit (2) of a pump, in particular an eccentric screw pump (3), with at least one first joint part (A) which has an end joint pin (10) and at least one second joint part (B) which has at least one has a joint mount (11) at the end, into which the joint pin (10) of the first joint part (A) engages in an articulated manner for the transmission of axial forces and torques, characterized in that the joint pin (10) has an outer contour (12) that is at least partially spherical or partially spherical in which several pocket-like depressions (14) are integrated distributed over the circumference, between which several wings (15) oriented in the radial direction are formed distributed over the circumference and that the joint receptacle (11) has a (corresponding) at least partially spherical or Has a (partially) spherical inner contour (13) and a plurality of projections (16) projecting inwards in the radial direction from the (partially) spherical inner contour, between which groove-like recesses (17) are formed, the wings (15) of the pivot pin ( 10) engage in the recesses (17) of the joint mount (11) and the projections (16) of the joint mount (11) engage in the depressions (14) of the pivot pin (10), so that (during operation) on the one hand via the interaction of the ( axial forces can be transmitted between the part-)spherical outer contour (12) and the (part-)spherical inner contour (13) and on the other hand a torque can be transmitted via the interaction of the wings (15) and the projections (16) and at the same time pivoting movements between the first joint part (A) and second joint part (B) are made possible.

Description

The invention relates to an articulated connection within a rotating unit of a pump, in particular within a rotating unit of an eccentric screw pump, having at least a first joint part, which has a pivot pin at the end and at least a second joint part, which has at least one joint receptacle at the end, into which the pivot pin of the first Joint part engages in an articulated manner for the transmission of axial forces and torques. The invention also relates to a rotating unit of a pump, in particular an eccentric screw pump, with one or more such articulated connections. Furthermore, the invention relates to an eccentric screw pump with a drive, a stator and with such a rotating unit. The rotating assembly has one or more articulations and hence joints designed to transmit torque and thrust over an articulated range of motion.

An eccentric screw pump is a pump from the group of rotating positive displacement pumps that are used to convey different media and in particular liquid media and also highly viscous liquids in a wide variety of industrial sectors. The liquids to be pumped can e.g. B. also contain solids.

The eccentric screw pump has at least one stator, a rotor rotating in the stator, a drive for the rotor and z. B. a pump housing connected to the stator, which is also referred to as a suction housing depending on the mode of operation and which has at least one housing opening (e.g. inlet opening) for the medium to be pumped. The drive (z. B. an electric motor) works on a centrally rotating shaft, which is z. B. can be a drive shaft or a stub shaft. The (centrically) rotating shaft works via a coupling device (e.g. a coupling rod) on the rotor or its rotor head, which rotates eccentrically, so that the coupling device generates or ensures the eccentricity. So e.g. For example, the shaft can be connected to the coupling device (e.g. coupling rod) via a first articulated connection, and the coupling device can in turn be connected to the rotor or the rotor head via a second articulated connection. The rotating unit of such an eccentric screw pump consequently comprises the shaft driven by the drive, the coupling device and the rotor or at least its rotor head.

The stator consists of z. B. elastic material and it is usually surrounded by a one-piece or multi-piece stator casing or stator housing (e.g. made of metal). The elastic (e.g. elastomeric) stator can be firmly connected to the stator casing, e.g. B. be vulcanized in this. Alternatively, the stator can also be surrounded by the stator casing in a detachable and thus replaceable manner. Alternatively, however, stators made of other materials, e.g. B. made of metal. In practice, the pump housing is also referred to as the suction housing. On the side facing away from the suction housing of the stator z. B. another housing part provided as a connecting piece, z. B. can be referred to as a pressure port.

Eccentric screw pumps of the type described are z. B. from the DE 10 2014 112 552 A1 , DE 10 2010 037 440 A1 , WO 2009/024279 A1 , DE 10 2018 113 347 A1 or DE 10 2016 121 581 A1 known.

In such eccentric screw pumps, the coupling device z. B. formed by a coupling rod and the articulations are often designed as pin joints and / or cardan joints. To compensate for eccentric movements, the coupling rod is linked to the rotor or rotor head on the one hand and the shaft (e.g. drive shaft or stub shaft) on the other by means of a pin joint. Such a bolt joint has on the one hand a pivot pin and on the other hand a joint receptacle, e.g. B. insertion receptacle for the associated pivot pin. The connection is made via coupling pins that are inserted into corresponding holes in the components.

An eccentric screw pump with pin joints in the coupling rod is z. B. from the DE 101 16 641 C2 known.

Based on this, the DE 10 2006 058 166 A1 Pin joints of an eccentric screw pump, in which guide bushings are inserted in the joint head bores.

Flexible connections can also be used as an alternative to pin joints. So describes z. B. the DE 298 12 846 U1 an eccentric screw pump in which the rotor, the coupling rod and the connecting shaft are designed as a one-piece component made of thermoplastic material, with joint-forming constrictions being integrated into this rotating unit (cf DE 298 12 846 U1 ).

Finally describes the DE 10 2019 107 078 A1 a joint of an eccentric screw pump, which comprises an inner connection part with an outer contour and an outer connection part with an inner contour, wherein between the inner connection part and the outer connection part a flexible or elastic intermediate layer is arranged. The inner contour and outer contour can be star-shaped or polygon-shaped.

The articulated connections described, which in practice are mainly designed as pin joints, have proven themselves extremely well in eccentric screw pumps for decades. However, they can be further developed. This is because the connections within the rotating unit are exposed to high loads during operation, with not only torques having to be transmitted, but also high axial forces or axial loads occurring within the rotating unit.

The object of the invention is to create an articulated connection that can be used as an optimized alternative to conventional pin joints, in particular within an eccentric screw pump or a rotating unit of an eccentric screw pump, and with which both high torques and high axial loads can be transmitted or absorbed with a simple and economical design .can be recorded.

To solve this problem, the invention teaches in a generic eccentric screw pump of the type described above that the pivot pin has an at least partially spherical or partially spherical outer contour, in which several pocket-like depressions are integrated distributed over the circumference, between which several, distributed over the circumference, wings oriented in the radial direction are formed and
that the joint mount has a (corresponding) inner contour that is at least partially spherical or (partially) spherical and several projections that protrude inwards from the (partially) spherical inner contour in the radial direction, between which groove-like recesses are formed, with the wings of the pivot pins extending into the recesses of the joint mount and the projections of the joint mount engage in the depressions of the pivot pin,
so that (during operation) on the one hand axial forces can be transmitted via the interaction of the (partially) spherical outer contour and the (partially) spherical inner contour and on the other hand via the interaction of the wings and the projections, a torque can be transmitted and at the same time pivoting movements between the first joint part and the second joint part are made possible.

The joint connection is particularly preferably designed in such a way that axial forces on the one hand and torque on the other hand are transmitted via separate areas of the joint connection, in that axial forces are transmitted exclusively via the interaction of the spherical or (partially) spherical outer contour and the spherical or (partially) spherical inner contour and torques are transmitted exclusively via the interaction of the vanes and recesses and/or the projections and recesses.

According to the invention, a new articulated connection is created, which in particular replaces the conventional pin joints within a rotating unit of a pump, e.g. B. can replace an eccentric screw pump. The invention is based on the knowledge that axial forces or pressure forces are optimally transmitted and absorbed within an articulated connection if maximum surfaces and consequently joint surfaces are realized. Furthermore, the invention is based on the finding that maximum and consequently optimal surfaces can be realized with a simultaneously minimum overall diameter of the articulated connection for the transmission of maximum axial loads by a spherical surface design, ie a spherical shape or part-spherical shape. Since such a joint geometry with spherical joint surfaces can absorb and transmit high axial forces and consequently compressive forces, but since an exclusively spherical design is not suitable for the transmission of torque, according to the invention, the spherical basic shape of the joint mount and joint pin is given a contour for the transmission of Torques are superimposed by the pivot pin being provided with pocket-like depressions and wings on the one hand and the joint mount with (corresponding) projections and recesses on the other hand, so that these form-fitting contours mesh like wings or gears for the transmission of torques. Thus, in a preferred embodiment, the pivot pin can have at least three wings and three recesses, preferably four wings and four recesses, and the joint receptacle can have at least three corresponding projections and three recesses, e.g. B. have four projections and four recesses. The pivot pin can form a mushroom head at its head-side end and consequently have a mushroom head shape, this mushroom head having a spherical or part-spherical outer contour which merges into the outer contour of the wings. The back of the mushroom head between the wings in the transition to the pocket-like depressions form undercuts, so that the connection is not easily released when subjected to tensile stress. Accordingly, the joint mount can form a mushroom-shaped recess at its inner end, the spherical inner contour of which merges into the inner contour of the groove-like recesses. It is advantageous if the axial forces exclusively via the interaction of the spherical or part-spherical outer contour or inner contour of the mushroom head and the mushroom-shaped Recess are transmitted and torques are transmitted exclusively via the wings and recesses or projections and depressions arranged behind the mushroom head or behind the mushroom-like recess.

In a particularly preferred embodiment, the outer contour of the pivot pin is constructed from one or more cycloidal curves in a cross-section in the area of the wings and indentations and consequently in the area in which torques are transmitted. Accordingly, the inner contour of the joint mount in a cross section in the area of the projections and recesses can (likewise) be constructed from one or more cycloidal curves. Particularly preferably, the outer contour of the pivot pin and/or the inner contour of the joint mount is constructed from a combination of an epicycloid curve and a hypocycloid curve. Alternatively, a combination of an epicycloid curve and an epitrochoid curve is possible. The cycloidal curve or curves can be superimposed on a spherical contour with the same diameter and origin.

A cycloidal curve is a curve or trajectory that describes a point on the circumference of a circle when this circle rolls on (any) rail curve. If it is a point on the circumference of a circle, which in turn rolls on the outside of a second circle, i.e. if the directrix itself is a circle, this cycloid curve is called an epicycloid. If the point on the circumference of the circle rolls within a second circle, it is called a hypocycloid. These curves of the ordinary cycloid always arise when a point that lies on the circumference of the first circle itself rolls on a second circle as a guide curve inside or outside. This must be distinguished from constructions in which a first circle rolls onto a second circle or in a second circle, but the point on which the construction is based does not lie on the circumference of the first circle, but either outside or inside it first circle. In this case, no ordinary cycloids arise, but rather lengthened or shortened cycloids, which are also referred to as trochoids. If the circle rolls off on the outside, an epitrochoid is formed. If the circle rolls inside, a hypotrochoid is formed.

In a particularly preferred embodiment, the contour responsible for torque transmission in the area of the vanes, recesses, projections and/or indentations is constructed by a combination of an epicycloid curve on the one hand and a hypocycloid curve on the other. For this purpose, reference is made to the description of the figures.

The invention is based on the finding that a geometry based on cycloids or cycloidal curves and in particular a combination of different types of cycloidal curves can be used to implement an optimized geometry for the transmission of high torques with a simultaneously small overall diameter of the joint connection. It is therefore possible not only to enlarge the surfaces responsible for power transmission, but also to distribute a large proportion of material - viewed in cross section - to surface areas that are at a maximum (radial) distance from the center or from the axis of the joint.

According to the invention, this contour, which is optimized for torque transmission and is based on cycloidal curves, is combined with a spherical or part-spherical outer contour for the transmission of pressure or axial forces. This combines the possibility of an optimal transmission of axial forces on the one hand and torques on the other hand in a uniform geometry in order to create an optimized articulated connection that can be used e.g. B. can be used within a rotating unit of an eccentric screw pump. Since the geometry according to the invention places an individual focus on axial forces on the one hand and torques on the other, the articulated connection and thus also the entire rotating unit can be realized with a small diameter.

In a particularly preferred development, the pivot pin engages directly in the joint mount and without an elastic intermediate layer, so that the joint function is realized solely by the geometry of the pivot pin and the joint mount and not by elastic material between the surfaces described.

The pivot pin is preferably formed in one piece and it can z. B. in one piece to the shaft, z. B. drive shaft, stub shaft or the like. In the same way, the pivot pin z. B. integrally formed on the rotor or the rotor end or a separate rotor head. A preferred embodiment provides a rotating unit of a pump, in particular an eccentric screw pump, which has a driven or drivable shaft, a rotor or rotor head rotating eccentrically to the shaft and a coupling device arranged between the shaft and rotor or rotor head to generate the eccentricity between shaft and rotor or rotor head. According to the invention, the shaft, for. B. drive shaft or stub shaft, with the first pivot pin armed. The rotor or its rotor head is equipped with a second pivot pin. The coupling device, which replaces a conventional coupling rod and can also be referred to as a coupling rod, is arranged between these pivot pins, with this coupling rod having an articulated receptacle both on the drive side and on the rotor side, into which the (two) described pivot pins engage in an articulated manner. This coupling device, which can also be referred to as a coupling rod, can be designed in one piece with the two pivot pins. However, the invention also includes embodiments in which—vice versa—the coupling device is equipped with one or more pivot pins and the shaft and/or the rotor with corresponding joint receptacles.

In order to simplify the assembly of the articulated connections and in particular the assembly of a rotating unit of an eccentric screw pump, it is optionally proposed that the joint mount be made up of several segments, e.g. B. composed of two half-shells, which are positively and detachably connected to each other, z. B. are screwed together or locked, z. B. by means of screw connection and / or locking or snap connection.

In the case of a rotating unit of a progressing cavity pump z. B. a central coupling device, z. B. provided a coupling rod having the two joint mounts. This coupling rod can then consist of z. B. two segments, z. B. be composed of two half-shells, so that during assembly, the pivot pin, z. B. can set the pivot pin of the shaft and the pivot pin of the rotor or rotor head between the half-shells, so that the articulated connection takes place in the course of joining the two half-shells. The two segments or half-shells differ over the entire length of the coupling rod and the parting plane between the segments runs along the longitudinal direction of the rotating unit or coupling rod.

As already described, the first joint part with the joint pin can be a driven or drivable shaft or part of a shaft. The first joint part with the pivot pin can also be part of a rotor or a rotor head, e.g. B. within an eccentric screw pump. The second joint part with the joint receptacle can be a shaft-driven or drivable coupling device or part of a coupling device, e.g. B. Part of a coupling rod. A coupling rod can be implemented within a rotating unit of an eccentric screw pump, each end having a second joint part of the type described with the joint mount.

For the transmission of torque, the construction described is essential, the z. B. may have wings and / or recesses and / or projections and / or depressions. These structures can in their respective end z. B. tapered to form a star-shaped cross-section or rounded.

Optionally, functional recordings, e.g. B. recesses can be integrated, the z. B. can accommodate additional components. Such additional components can be z. B. electronic components, preferably sensors. Particularly preferably, these functional recordings in the segments, z. B. half-shells can be integrated.

The joint part, z. B. the first joint part and / or second joint part can be made by shaping manufacturing processes such. B. produce the injection molding, transfer molding, pressing or extrusion. Optionally or additionally, subtractive manufacturing processes, e.g. B. a machining can be used. Furthermore, the production can be done by an additive manufacturing process, e.g. B. done by 3D printing. If the respective joint parts are parts of certain components of a rotating unit (e.g. shaft, coupling device/coupling rod, rotor head or rotor), these components can be produced directly in one piece with the respective joint part using the manufacturing processes described, e.g. B. a one-piece coupling rod with joint mounts at the ends.

In a particularly preferred embodiment of the invention, the first joint part and/or the second joint part or the components of the rotating unit equipped with these joint parts (e.g. rotor, rotor head, shaft, coupling rod) are at least partially or completely made of a material based on a made of high-performance thermoplastic polymer. The articulated connection consequently consists of parts or components that are made entirely or partially or in regions from a thermoplastic high-performance polymer or based on a thermoplastic high-performance polymer and preferably from a modified high-performance polymer or polymer compound. A partially crystalline and/or aromatic polymer can be used as the high-performance polymer. The high-performance polymer can (e.g. as a base polymer) contain aromatic paraphenylene molecular chains which alternate with sulfide compounds, thus forming a semi-crystalline structure whose Fes activity increases with increasing temperature. It can be e.g. B. be an aromatic polysulfide, z. B. Polyphenylene sulfide (PPS). Alternatively, the high-performance polymer can be an aromatic polyetherketone (PEK) or polyaryletherketone (PAEK). The aromatic polyaryletherketone can be e.g. B. be a polyetheretherketone (PEEK).

Optionally, a modified plastic is used as the material of the respective joint part, which has a base plastic or a base polymer and one or more additives, the base plastic being a high-performance thermoplastic polymer, e.g. B. one of the high-performance thermoplastic polymers described. The plastic may be modified/reinforced with one or more additives that allow operation at temperatures in excess of 150°C, reduce friction between components and/or strengthen the material at high loads, e.g. B. in the case of temporary torque peaks. Appropriate additives can reduce friction, reduce the surface modulus of elasticity, increase high-temperature performance and/or improve self-lubricating properties. In addition, one or more additives can be used to increase the load-bearing capacity of the components, in particular with regard to compression due to high axial forces and shearing forces due to torque transmission during operation.

The modified plastic can have at least one friction-reducing additive as an additive. Alternatively or additionally, the modified plastic can have at least one reinforcing additive as an additive. The reinforcing additive may be reinforcing fibres, e.g. B. act inorganic reinforcing fibers, z. B. glass fibers, carbon fibers, basalt fibers, boron fibers, ceramic fibers, silica fibers and / or quartz fibers. As a friction-reducing additive, the material can be a fluoropolymer, e.g. B. PTFE (Teflon) included. Alternatively or additionally, the material can contain at least one solid lubricant, e.g. B. graphite, molybdenum disulfide, tungsten disulfide or a solid lubricant based on ceramics, soft metals and / or precious metals or combinations thereof.

It is a particular advantage of the invention that the composition of the materials described (high-performance polymer, reinforcement additive and/or friction-reducing additive), e.g. B. PEEK, PTFE and carbon) a material with excellent properties, in particular a self-lubricating material, is used for the joint according to the invention. The material according to the invention is excellently suited for the described applications involving movement and wear and consequently for use in joints. In addition, the (self-lubricating) material described has an extremely low coefficient of sliding friction, which means that the maintenance effort can be significantly reduced. Thanks to the higher abrasion resistance compared to other materials, the joints can have a longer service life and, in particular, a longer service life for the pump.

• Hochleistungspolymer (z. B. aromatisches Polymer: 30 bis 70 Gew.-%, vorzugsweise 40 bis 60 Gew.-%, z. B. 50 Gew.-%
• Verstärkungszusatz: 20 bis 60 Gew.-%, vorzugsweise 30 bis 50 Gew.-%, z. B. 40 Gew.-%
• Reibungsmindernder Zusatz: 1 bis 20 Gew.-%, vorzugsweise 5 bis 15 Gew.-%, z. B. 10 Gew.-%.

In a preferred embodiment, the material of the respective joint part is composed as follows:

• High performance polymer (e.g. aromatic polymer: 30 to 70% by weight, preferably 40 to 60% by weight, e.g. 50% by weight
• Reinforcement additive: 20 to 60% by weight, preferably 30 to 50% by weight, e.g. B. 40% by weight
• Friction reducing additive: 1 to 20% by weight, preferably 5 to 15% by weight, e.g. B. 10% by weight.

According to the invention, there is above all the possibility of using the components used, e.g. B. the joint parts or the shaft, coupling rod and / or the rotor or rotor head, not to be manufactured homogeneously from a single material, but to manufacture different areas of the workpiece from different materials in order to adapt the properties to the respective conditions in the area of the workpiece . So e.g. B. in the area of the surfaces of the spherical outer contour and inner contour on the one hand and the pocket-like depressions and projecting projections or recesses and wings on the other hand, different materials can be used. In this way, there is the possibility of adjusting the strength in areas of particularly high stress and/or adjusting the friction properties in areas with high relative movements. For this purpose, the materials essential to the invention can be used, with material properties that are selectively adapted to the respective area, e.g. B. the same base plastic or the same base polymer has different additives in different spatial areas of the joint. For example, in areas where strength is paramount, it may be advisable to add reinforcing fibers. In surface areas in which certain friction properties are important, appropriate additives with friction-reducing additives can be provided. Overall, the invention offers diverse and variable optimization options.

In this context, the construction described above is advantageous in the axial Forces on the one hand and torques on the other hand are transmitted in different areas of the respective joint part or different areas of the joint part are set up for the transmission of different forces, so that the respective surface or the respective area can be adapted in a targeted manner by selecting a suitable material.

• 1 eine Exzenterschneckenpumpe in einer vereinfachten Seitenansicht,
• 2a bis e einen Teil einer rotierenden Einheit einer Exzenterschneckenpumpe nach 1 in verschiedenen Ansichten,
• 3a bis d einen Rotorkopf mit einem ersten Gelenkteil in verschiedenen Ansichten,
• 4a bis d eine Kupplungseinrichtung bzw. Kuppelstange mit zweiten Gelenkteilen in verschiedenen Ansichten und
• 5a bis d eine Welle einer rotierenden Einheit mit einem ersten Gelenkteil in verschiedenen Ansichten.

The invention is explained in more detail below with reference to drawings which merely show an exemplary embodiment. Show it

• 1 a progressing cavity pump in a simplified side view,
• 2a to e a part of a rotating unit of an eccentric screw pump 1 in different views,
• 3a until i.e a rotor head with a first joint part in different views,
• 4a until i.e a coupling device or coupling rod with second joint parts in different views and
• 5a until i.e a shaft of a rotating unit with a first joint part in different views.

In 1 an eccentric screw pump 3 is shown, which in its basic structure has a stator 4 , a rotor 5 rotating in the stator 4 and a drive 9 for the rotor 5 . The progressing cavity pump can have a (central) pump housing 21 which is also referred to as the suction housing 21 . In this case, the pump housing 21 is connected to the stator 4 on the suction side. On the opposite side of the pump housing z. B. another housing part 23 is connected, which is also referred to as the pressure port 23. The pump housing 21 has a housing opening 22 which z. B. serves as an inlet opening for the medium to be pumped, so that - depending on the operating direction - the medium z. B. is conveyed from the pump housing via the stator/rotor to the pressure port. The drive drives a shaft 7, which is designed or referred to as a drive shaft or as a stub shaft. This shaft 7 rotates centrically. The end of the rotor 5 , which is also referred to as the rotor head 6 , is connected to the shaft 7 via a coupling device 8 . The shaft 7 is connected to the coupling device 8 via a joint connection 1 and the rotor or the rotor head 6 is connected to the coupling device 8 via a joint connection 1, so that the eccentric movement of the rotor head 6 is ensured. Consequently, two articulated connections 1 are implemented, on the one hand between the shaft 7 and the coupling device 8 and on the other hand between the coupling device 8 and the rotor or rotor head 6. The unit made up of the shaft 7, coupling device 8 and rotor (or at least the rotor head) and driven in rotation by the drive 9 is also referred to as a rotating unit, in which preferably two articulated connections 1 or joints are integrated.

Each of these two joint connections 1 has a first joint part A, which has an end joint pin 10, and a second joint part B, which has an end joint socket 11, the joint pin 10 of the first joint part A being articulated in the joint socket for the transmission of axial forces and torques 11 of the second joint part B engages. The design of these joint parts A, B or the joint receptacle 11 and the joint pin 10 is of particular importance according to the invention.

It is provided that the pivot pin 10 has an outer contour 12 that is at least partially spherical or partially spherical, in which several pocket-like depressions 14 are integrated distributed over the circumference, between which several wings 15 oriented in the radial direction are formed distributed over the circumference. Accordingly, the joint mount 11 has a corresponding, at least partially spherical or partially spherical inner contour 13 and a plurality of projections 16 projecting inwards from this inner contour in the radial direction, between which groove-like recesses 17 are formed. The wings 15 of the pivot pin 10 engage in the recesses 17 of the pivot mount 11 and the projections 16 of the pivot mount 11 engage in the depressions 14 of the pivot pin 10. In this way, during operation and consequently during the rotation of the rotating unit 2, on the one hand, via the interaction axial forces are transmitted/absorbed by the spherical outer contour 12 and the spherical inner contour 13 and, on the other hand, a torque is transmitted via the interaction of the wings 15 and the projections 16, and at the same time this construction enables pivoting movements between the first joint part A and the second joint part B.

The illustrated embodiment is characterized above all by the fact that axial forces on the one hand and torque on the other hand are transmitted via regions of the articulated connection 1 that are separate from one another. This is because axial forces are absorbed or transmitted exclusively via the interaction of the spherical or part-spherical outer contour 12 and the spherical or part-spherical inner contour 13 . In contrast, torques are transmitted exclusively via the interaction of the wings 15 and recesses 17 and/or the projections 16 and depressions 14.

In the exemplary embodiment shown, the pivot pin 10 has four wings 15 and four indentations 14 and the joint receptacle 11 has four projections 16 and four recesses 17, so that a four-winged geometry for transmitting the torques is realized. It can be seen in the figures that the pivot pin 10 forms a mushroom head 18 at its head-side end, the spherical outer contour 12 of which merges into the wings 15 . The back of the mushroom head 18 between the wings 15 form an undercut 20 in the transition to the pocket-like depressions 14. The joint receptacle 11 forms a mushroom-shaped recess 19 at its inner end, the spherical inner contour 13 of which merges into the inner contour of the channel-like recesses 17. In this way, axial forces are transmitted exclusively via the interaction of the spherical contours 12, 13 of the mushroom head 18 or the mushroom-shaped recess 19. Torques are transmitted exclusively via the wings 15 and recesses 17 as well as projections 16 and depressions 14 arranged behind the mushroom head 18 and behind the mushroom-head-like recess 19 .

The drawings therefore make it very clear (by way of example) that the construction provides different areas for the transmission of axial forces on the one hand and torques on the other. Of particular importance is the fact that, on the one hand, axial forces, e.g. B. compressive forces are transmitted or such axial forces are absorbed, which are of enormous importance in a rotating unit of an eccentric screw pump and may be significantly higher or possibly several orders of magnitude higher than the torques to be transmitted. The wing-like construction for transmitting the torque is integrated into the spherical contour or superimposed on it. Despite the spherical contours, which are actually not suitable for the transmission of torque, this construction allows torque to be transmitted.

In the illustrated, preferred embodiment of the invention, the wing-like constructions for transmitting the torque are characterized by a particularly advantageous geometry, because the outer contour 12 of the pivot pin 10 is constructed in a cross section in the area of the wing 15 and the recesses 14 from one or more cycloidal curves . The same applies to the inner contour 13 of the joint mount 11, which is constructed in a cross section in the area of the projections 16 and recesses 17 from one or more cycloidal curves. In the illustrated embodiment, the outer contour 12 and the inner contour 13 are each constructed from a combination of an epicycloid curve and a hypocycloid curve. This configuration is particularly advantageous because a large surface area is made available for the transmission of the torques, and yet maximum material and surface area are provided in areas of the connection that are positioned far away from the axis of rotation in the radial direction. Because in these areas, which are far away from the center point or from the axis of rotation in the radial direction in the course of the rotation, maximum forces arise that are well absorbed by the construction according to the invention.

Moreover, it can be seen in the figures that the coupling rod 8 and thus also the joint parts B integrated therein with the joint receptacles 11 are composed of two segments 11A, 11A each, which form half-shells and which are connected to one another in a form-fitting and detachable manner, e.g. B. screwed together or locked by a snap connection. This makes it easy to assemble the rotating unit 2 .

It is advantageous to manufacture the components A and B shown in the figures and in particular the rotor head 6, the shaft 7 and the coupling rod 8 from a thermoplastic high-performance polymer or based on a thermoplastic high-performance polymer, which is z. B. may be a semi-crystalline and / or aromatic polymer, z. B. PPS, PAEK or PEEK. A modified plastic is preferably used as the material for these components, which has a base plastic and one or more additives, it being possible for the base plastic to be the high-performance polymer described. As additives z. B. a friction-reducing additive and / or a reinforcing additive in question, the reinforcing additive z. B. can be reinforcing fibers. A fluoropolymer, for example PTFE, can be used as a friction-reducing additive.

The components 6, 8 and/or 7 shown can be manufactured on the basis of a high-performance plastic by injection molding, transfer molding, compression molding or extrusion or by an additive manufacturing process, e.g. B. by 3D printing. It is also possible to construct different areas of the components from different materials with different properties, so that z. B. heavily stressed areas can be made of a material with higher strength and areas with high relative movements with friction-reducing properties.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102014112552 A1 [0005]
• DE 102010037440 A1 [0005]
• WO 2009/024279 A1 [0005]
• DE 102018113347 A1 [0005]
• DE 102016121581 A1 [0005]
• DE 10116641 C2 [0007]
• DE 102006058166 A1 [0008]
• DE 29812846 U1 [0009]
• DE 102019107078 A1 [0010]

Claims (23)

Articulated connection (1) within a rotating unit (2) of a pump, in particular an eccentric screw pump (3), with at least one first joint part (A) which has an end joint pin (10) and at least one second joint part (B) which has at least one has a joint receptacle (11) at the end, into which the joint pin (10) of the first joint part (A) engages in an articulated manner for the transmission of axial forces and torques, characterized in that the joint pin (10) has an outer contour (12) that is at least partially spherical or partially spherical in which several pocket-like depressions (14) are integrated distributed over the circumference, between which several wings (15) oriented in the radial direction are formed distributed over the circumference and that the joint receptacle (11) has a (corresponding) at least partially spherical or Has a (partially) spherical inner contour (13) and a plurality of projections (16) projecting inwards in the radial direction from the (partially) spherical inner contour, between which groove-like recesses (17) are formed, the wings (15) of the pivot pin ( 10) engage in the recesses (17) of the joint mount (11) and the projections (16) of the joint mount (11) engage in the depressions (14) of the pivot pin (10), so that (during operation) on the one hand via the interaction of the ( axial forces can be transmitted between the part-)spherical outer contour (12) and the (part-)spherical inner contour (13) and on the other hand a torque can be transmitted via the interaction of the wings (15) and the projections (16) and at the same time pivoting movements between the first joint part (A) and second joint part (B) are made possible. joint connection claim 1 , characterized in that axial forces on the one hand and torque on the other hand are transmitted via separate areas of the articulated connection (1), in that axial forces are transmitted exclusively via the interaction of the spherical or (partially) spherical outer contour (12) and the spherical or (partially) spherical inner contour (13) are transmitted and torques are transmitted exclusively via the interaction of the wings (15) and recesses (17) and/or the projections (16) and depressions (14). joint connection claim 1 or 2 , characterized in that the pivot pin (10) has at least three wings (15) and three recesses (14), z. B. four wings and four recesses, and the joint receptacle (11) at least three corresponding projections (16) and three recesses (17), z. B. has four projections and four recesses. Joint connection according to one of Claims 1 until 3 , characterized in that the pivot pin (10) forms a mushroom head (18) at its head end, the (partially) spherical outer contour (12) of which merges into the outer contour of the wings (15) and that the rear side of the mushroom head (18) is between form undercuts (20) on the wings (15) in the transition to the pocket-like depressions (14). Joint connection according to one of Claims 1 until 4 , characterized in that the joint receptacle (11) forms a mushroom-shaped recess (19) at its inner end, the spherical inner contour (13) of which merges into the inner contour of the channel-like recesses (17). joint connection claim 4 or 5 , characterized in that axial forces are transmitted exclusively via the interaction of the spherical or (partially) spherical outer contour (12) or inner contour (13) of the mushroom head (18) or the mushroom-shaped recess (19) and torques are transmitted exclusively via the behind the Mushroom (18) or the mushroom-like recess (19) arranged wings (15) and recesses (17) or projections (16) and depressions (14) are transferred. Joint connection according to one of Claims 1 until 6 , characterized in that the pivot pin (10) engages directly in the pivot mount (11) without an elastic intermediate layer, so that the pivot function is realized solely by the geometry of the pivot pin (10) and the pivot mount (11) and not by elastic material. Joint connection according to one of Claims 1 until 7 , characterized in that the pivot pin (10) is formed in one piece. Joint connection according to one of Claims 1 until 8th , characterized in that the joint mount (11) consists of at least two segments (11 a, 11 b), z. B. two half-shells composed, which are positively and detachably connected to each other, z. B. are screwed together. Joint connection according to one of Claims 1 until 9 , characterized in that the outer contour (12) of the pivot pin (10) in a cross-section in the area of the wings (15) and recesses (14) is constructed from one or more cycloidal curves. Joint connection according to one of Claims 1 until 10 , characterized in that the inner contour (13) of the joint mount (11) is constructed in a cross section in the region of the projections (16) and recesses (17) from one or more cycloidal curves. joint connection claim 10 or 11 , characterized in that the outer contour (12) of the pivot pin (10) and/or the inner contour (13) of the joint mount (11) is constructed from a combination of an epicycloid curve and an epitrochoid curve or from a combination of an epicycloid curve and a hypocycloid curve or are constructed. Joint connection according to one of Claims 1 until 12 , characterized in that the first joint part (A) with the pivot pin (10) is a (driven or drivable) shaft (7) or part of a shaft (7). Joint connection according to one of Claims 1 until 13 , characterized in that the second joint part (B) with the joint receptacle (11) is a coupling device (8) (driven or can be driven, for example by a shaft) or is part of a coupling device (8). Joint connection according to one of Claims 1 until 14 , characterized in that the first joint part (A) with the pivot pin (10) is part of a rotor (5) or a rotor head (6), z. B. is part of a rotor (5) or rotor head (6) in an eccentric screw pump (3). Joint connection according to one of Claims 1 until 15 , characterized in that the wings (15) and/or the corresponding recesses (17) and/or the projections (16) and/or the corresponding depressions (14) taper to a point in their respective end region, forming a star-shaped cross section or are rounded is/are. Joint connection according to one of Claims 1 until 16 , characterized in that functional recordings, eg recesses, for additional components, eg for electronic components, preferably for sensors, are integrated into the joint receptacle (11), these functional recordings preferably being integrated into the segments (11a, 11b), eg half-shells are. Joint connection according to one of Claims 1 until 17 , characterized in that the first joint part (A) and/or the second joint part (B) is/are produced by injection molding, transfer molding, pressing, extrusion or by a subtractive manufacturing process or by an additive manufacturing process. Joint connection according to one of Claims 1 until 18 , characterized in that the first joint part (A) and/or the second joint part (B) is or are made at least partially or completely from a material based on a high-performance thermoplastic polymer. Joint connection according to one of Claims 1 until 19 , characterized in that different materials are used at least in the area of the surfaces of the spherical outer contour (12) and inner contour (13) on the one hand and the pocket-like depressions (14) and protruding projections (16) or recesses (17) and wings (15) on the other become. Rotating unit (2) of a pump, in particular an eccentric screw pump (3), with at least one articulated connection (1) according to one of Claims 1 until 20 , characterized in that the first joint part (A) with the joint pin (10) is a shaft (7) or part of a shaft (7) and that the second joint part (B) with the joint mount (11) is a coupling device driven by the shaft or is part of a coupling device (8). Rotating unit after Claim 21 , with a driven or drivable shaft (7), a rotor (5) or rotor head (6) rotating eccentrically to the shaft and a coupling device (8) arranged between the shaft (7) and rotor (5) or rotor head (6). Generating the eccentricity, characterized in that the shaft (7) has a first pivot pin (10) which engages in an articulated manner in a first joint receptacle (11) of the coupling device (8) and that the rotor (5) or its rotor head (6) has a second pivot pin (10) which engages in an articulated manner in a second pivot mount (11) of the coupling device (8). Eccentric screw pump (3) with a drive (9), a stator (4) and with a rotating unit (2). Claim 21 or 22 .

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