DE102014104710A1 - Fluid pump with bearing with laterally compact switching body with two opposite convex coupling flaps - Google Patents

Abstract

Fluid pump (20) for pumping fluid in a sample separation device (10), wherein the fluid pump (20) has a piston as the first coupling body (202), which is arranged for reciprocating in a piston chamber (210) for conveying fluid, an actuator as a second coupling body (204) arranged to transmit a force for driving the piston in the piston chamber (210), and a bearing device (200) for transmitting a force between the first coupling body (202) and the second coupling body (204), wherein the Bearing device (200) has at least one switching body (206), wherein the switching body (206) has a cap-shaped convex first coupling surface (300) for coupling to the first coupling body (202), one of the first coupling surface (300) opposite the cap-shaped convex second coupling surface (302 ) for coupling to the second coupling body (204), and a connection pin (304) between the first coupling surface (300) and the second coupling surface che (302).

Description

TECHNICAL BACKGROUND

 The present invention relates to a fluid pump, as well as a sample separation apparatus and a manufacturing method.

In an HPLC, a liquid (mobile phase) is typically run at a very precisely controlled flow rate (for example in the range of microliters to milliliters per minute) and at a high pressure (typically 20 to 1000 bar and beyond, currently up to 2000 bar). , in which the compressibility of the liquid can be felt, by a so-called stationary phase (for example, in a chromatographic column), moved to separate individual components of a sample liquid introduced into the mobile phase from each other. Such an HPLC system is known, for example from the EP 0,309,596 B1 same Applicant, Agilent Technologies, Inc.

 The pump, which conveys the mobile phase at high pressure, may have in a piston chamber there a reciprocating piston which makes the displacement of the fluid. The piston itself is driven on a coupling surface of a motor-driven actuator, for example, which presses against the piston on the coupling surface. In this case, it can occur at the interface between the piston and the actuator for the occurrence of force peaks, for example, when the coupling surfaces are slightly tilted or shifted against each other. This reduces the life of the pump.

 In order to allow a component-sparing force compensation between two abutting coupling surfaces, a ball bearing can be arranged between the coupling surfaces. This is formed from one or more balls, which act as a force mediator between the coupling surfaces. However, the space required for such a ball bearing is relatively high, which is contrary to the trend towards progressive miniaturization.

US 5,415,489 discloses a mechanical coupling having a drive shaft which is reciprocally arranged along an axis. An actuator shaft is mounted for reciprocation along the axis. A clutch mechanism is provided for transmitting the reciprocating movement of the drive shaft to the actuator shaft. The coupling mechanism is provided with a pivot joint to effect relative rotational movement between the drive shaft and the actuator shaft, and a translational joint permits relative translational movement between the drive shaft and the actuator shaft in directions transverse to the axis. The translational joint is equipped with a flexible connector for connecting the pivot and the drive shaft.

US 5,887,507 discloses a piston pump in which a piston is clamped by a spring via a thrust bearing with rolling elements clamped by a pair of bearing discs on a shaft.

EPIPHANY

 It is an object of the invention to enable a space-saving and component-friendly power coupling between two coupling surfaces of a fluid pump. The object is achieved by means of the independent claims. Further embodiments are shown in the dependent claims.

 According to an exemplary embodiment of the present invention, a fluid pump is provided for pumping fluid (ie, a liquid and / or a gas, optionally comprising solid particles) in a sample separator, wherein the fluid pump is a piston as a first coupling body, which is reciprocatable in a for conveying fluid in a Piston chamber is arranged, a (in particular motor-driven) actuator as a second coupling body, which is arranged to transmit a force for driving the piston in the piston chamber, and a bearing device for transmitting a force between the first coupling body and the second coupling body, wherein the bearing device at least a (in particular rigid) switching body, wherein the switching body has a cap-shaped (in particular dome-shaped or dome-shaped) convex (ie curved outward) first coupling surface to (in particular direct, ie without intermediate body, or indire coupling, i.e. with an intermediate body therebetween) coupling to the first coupling body, a cap-shaped (in particular dome-shaped or dome-shaped) convex (in particular dome-shaped or dome-shaped) opposite the first coupling surface. convex to the second coupling body, and a (in particular non-spherical, ie deviating from a spherical shape) connecting pin between the first coupling surface and the (. In particular direct, ie without intermediate body, or indirect, ie having second coupling surface.

According to yet another exemplary embodiment, a sample separator is provided for separating a mobile phase fluid sample into fractions, the sample separator comprising a fluid pump having the above-described features for driving at least one of the mobile phase and the fluid sample through the sample Sample Separator is configured, and a separation device downstream of the fluid pump for separating the different fractions of the mobile phase in the sample has.

 According to still another exemplary embodiment, a method of manufacturing a bearing device (in particular, a method of manufacturing a fluid pump for pumping fluid in a sample separator, the fluid pump being equipped with such a bearing device) for communicating a force between a piston as a first coupling body and an actuator provided as a second coupling body, wherein in the method, the bearing device is formed with at least one switching body, the at least one switching body is formed with a cap-shaped convex first coupling surface for coupling to the first coupling body, the at least one switching body with a first coupling surface opposite the cap-shaped convex second coupling surface is formed for coupling to the second coupling body, and a (in particular non-spherical) connecting pin between the first coupling surface and the second Coupling surface is provided.

 According to an exemplary embodiment, a fluid pump is provided with a bearing device, which acts as a force mediator between two coupling bodies by two convex coupling surfaces acting on the respective coupling body and arranged between the coupling surfaces pin or pin-shaped material block rigidly transmits the forces acting. In this case, the at least one switching body can be mounted as a whole to perform a rolling lever-like compensating movement between the two coupling bodies, so that under sliding of the coupling body along the respective convex coupling surfaces a low-side transmission of the force to be transmitted is possible. The lateral outer surface of the exchange body, which itself is not in direct operative contact with the respective coupling body, is advantageously pin-like-compact and preferably non-spherical, and is thus in particular reduced or slimmed over a comparatively considered ball geometry of a ball bearing. By reducing the volume of the side surface of the connection pin relative to a virtual comparison ball (corresponding to an imaginary material removal of the virtual comparison ball for forming the connection pin from the comparison ball), the space requirement in a plane vertical to the longitudinal axis of the connection pin between the two coupling bodies is significantly reduced. This is a space-saving and compact design of the storage device allows, which is particularly advantageous in providing a plurality, further in particular a plurality of switching bodies. The cap-shaped ends of the exchange body close this axially and form closed, continuous convex end portions as rolling surfaces for the respective coupling body, so that it can roll around an off-axis convex extremum of the cap around.

 An implementation of the bearing device described in a fluid pump, in particular in a sample separator, is particularly advantageous for transmitting a force from an actuator to a piston and thereby a balancing or load transfer function between the possibly not completely aligned coupling bodies in the form of piston and actuator exercise. The compact geometry of the bearing device not only promotes the possibility of producing miniaturized fluid pumps, but is also compatible with the high forces associated with high pressure pumps (for example, with delivery pressures in the range of over 600 bar, especially over 1200 bar) in sample separation equipment (such as a Flüssigchromatographieapparatur) occur.

 In addition, additional embodiments of the pump, the sample separation device and the method will be described.

 According to one embodiment, the first coupling surface may have a spherical surface segment and / or the second coupling surface may have a spherical surface segment. Thus, the exchange body may be formed as a pin with two attached to opposite ends ball caps. The two spherical surface segments can lie on a common spherical surface or on two different spherical surfaces (with the same or different radii and / or the same or different centers). The formation in particular of both coupling surfaces of the switching body as segments of a spherical surface allows a preferably all-side suppression of lateral forces (perpendicular to the axis of the power transmission), even if one of the coupling body with a spatial displacement or tilting acts on the respective coupling surface of the switching body (condition in that both the piston and the actuator are guided at least approximately in their own axis, and in particular can not escape themselves).

According to an exemplary embodiment, the switching body may have a reduced volume compared with a virtual sphere having a diameter which corresponds to a maximum distance between the first coupling surface and the second coupling surface. Between the two maximum points of each other opposite spherical surface segments, for the example of two spheres of the same radius a virtual sphere can be devised, the surface of which includes the two spherical coupling surfaces. According to such an embodiment, the connection pin can be located completely inside the imaginary sphere, so that in comparison to a ball bearing, the storage device according to the invention requires a reduced volume expenditure and in particular space requirement in the lateral direction of the connecting pin or pins. This allows a compact arrangement of the storage device or the ability to increase the number of switching bodies in an available space, whereby the power switching function can be further refined or divided under the protection of the storage device on multiple contact surfaces.

 According to an exemplary embodiment, a maximum length of the exchange body between the first coupling surface and the second coupling surface may be equal to a sum of a radius of the spherical surface segment of the first coupling surface and a radius of the spherical surface segment of the second coupling surface. The two points in the axial direction to each other maximum points on the two spherical surface segments may be according to this particularly preferred embodiment of a sum of the radius of the first ball surface segment corresponding ball and the radius of the second ball surface segment corresponding ball. Preferably, the two radii are identical in order to achieve a particularly symmetrical and tilt-protected switching body. If a tilting force then occurs on one of the two coupling surfaces, this results in the transmission of a force between the first coupling body and the second coupling body without the occurrence of transverse forces. The lateral bearing forces can thus be kept low and the life of the bearing device can be increased.

 According to one exemplary embodiment, the connection pin can have a constant cross-section (in particular with regard to cross-sectional area and / or cross-sectional shape) along a longitudinal axis between the first coupling surface and the second coupling surface. Between the two convex coupling surfaces, which may preferably have identical geometry, a symmetrical geometry along the longitudinal axis of the connecting pin can thus be achieved, which in turn reduces the occurrence of undesired bearing forces. Advantageously, the connection pin between the two coupling surfaces can be a rotationally symmetrical body.

 According to one exemplary embodiment, an outer surface of the connecting pin between the first coupling surface and the second coupling surface may be circular-cylindrical or polygonal, in particular hexagonal. According to a preferred embodiment of the connection pin can thus be a circular cylindrical pin, the two top surfaces but in comparison to a circular cylinder convex rounded, in particular spherical rounded, may be. The geometry described allows for arranging a plurality of connecting pins with a very high packing density and with a very low risk of undesired interaction between adjacent connecting pins. Alternatively, a polygonal geometry of the connecting pins in a sectional plane perpendicular to the longitudinal axis of the same may be advantageous, for example, to form in plan view or cross-sectional view honeycomb / hexagonal connecting pins. This also allows a particularly space-saving arrangement of a plurality of connecting pins in a matrix-shaped or honeycomb-shaped arrangement. Alternatively, it is also possible to buckle the connecting pins in the longitudinal axis concave or convex.

 According to one embodiment, the at least one switching body may be formed in one piece, in particular one-material. Such an integral configuration is mechanically stable and easily manufacturable.

 According to one embodiment, the connection pin may be bounded in the direction between the first coupling surface and the second coupling surface in cross section by non-spherical, in particular rectilinear, boundary lines. Although the boundary lines of the preferably rotationally symmetrical connection pins can be concave or convex, this should preferably lead to a smaller volume compared to the comparison ball described above.

According to an embodiment, the storage device may include a plurality of exchanges. According to a further exemplary embodiment, the connection pins of a plurality of switching bodies in the power-free state can preferably be arranged parallel to one another. By providing a plurality of switching bodies, a planar bearing or a planar bearing can be generated, which enables a two-dimensional and less tipping-prone power transmission, in particular when two flat coupling bodies meet. The connecting pins can be designed so that, for example, when no transverse force acting on one or both of the convex coupling surfaces, they are aligned with each other with parallel longitudinal axes. The contact surfaces of the respective on a common side, that is adjacent to the respective coupling body, convex coupling surfaces of the switching body, can thus in a common Coupling level, whereby the storage device is configured to provide a planar bearing function.

von Vermittlungskörpern aufweisen, wobei n Null oder eine ganze positive Zahl ist. Gemäß einer einfachsten Ausgestaltung kann nur ein einziger Vermittlungskörper vorgesehen werden (n = 0). Platzsparend können bei einer weiteren zweidimensionalen Erweiterung der Lagervorrichtung sechs weitere Vermittlungskörper um den einen Vermittlungskörper herum angeordnet werden, d.h. insgesamt sieben Vermittlungskörper (n = 1). Bei einer Erweiterung zu einer nächsten Stufe könnten um die sechs Vermittlungskörper herum weitere zwölf Vermittlungskörper angeordnet werden, d.h. insgesamt neunzehn Vermittlungskörper (n = 2), usw. Für diese Spezialfälle ist eine besonders platzsparende Anordnung von Vermittlungskörpern ermöglicht. Alternativ ist auch eine matrixförmige Anordnung der Vermittlungskörper entlang von Zeilen und Spalten möglich. Schließlich ist bei einer anderen, besonders platzsparenden und dennoch zweidimensionalen Anordnung von Vermittlungskörpern das Vorsehen von drei Vermittlungskörpern vorteilhaft, die ohne mechanische Überbestimmung an beiden gegenüberliegenden Seiten von je drei Koppelflächen eine verkippfreie Kontaktierung des jeweiligen Koppelkörpers ermöglichen. In letzterem Falle ist es möglich, ein Taumeln der Kontaktflächen zuzulassen. Vorzugsweise können drei solche Vermittlungskörper an Ecken eines gedachten gleichseitigen Dreiecks angeordnet werden.According to an embodiment, the storage device may include a number

of switching bodies, where n is zero or a whole positive number. According to a simplest embodiment, only a single switching body can be provided (n = 0). To save space, in a further two-dimensional expansion of the storage device, six further switching bodies can be arranged around the one switching body, ie a total of seven switching bodies (n = 1). In an extension to a next stage could be arranged around the six switching bodies around twelve more switching bodies, ie a total of nineteen switching body (n = 2), etc. For these special cases, a particularly space-saving arrangement of switching bodies is possible. Alternatively, a matrix-like arrangement of the switching bodies along rows and columns is also possible. Finally, in another, particularly space-saving and yet two-dimensional arrangement of switching bodies, the provision of three switching bodies advantageous that enable a tilt-free contacting of the respective coupling body without mechanical over-determination on both opposite sides of three coupling surfaces. In the latter case, it is possible to allow tumbling of the contact surfaces. Preferably, three such switching bodies can be arranged at corners of an imaginary equilateral triangle.

 According to one embodiment, the storage device may have a support structure in which the at least one switching pin or switching body is arranged to support. Such a support structure, which may also be referred to as a separator, may serve as a receiving structure for the at least one, preferably for the plurality, switching bodies. The support structure thus serves illustratively as a matrix into which the switching body or agents are embedded or stored. The support structure may be fixedly connected to the respective coupling body on one of its two opposite surfaces, or may allow free movement of the entire bearing device between the two separately movable coupling bodies.

 According to one exemplary embodiment, the support structure can be designed to arrange the at least one switching body in such a supporting manner that the respective first coupling surface and / or the respective second coupling surface projects or protrudes with respect to the support structure. According to this embodiment, the convex coupling surfaces of the switching body or parts protrude on both sides relative to the support structure in order to be vulnerable exposed as actual force transmission and force application surfaces for the coupling bodies. On the other hand, along the remaining longitudinal extent of the switching bodies, in particular along the entire connecting pins, the supporting structure can embed the respective section of the switching bodies.

 According to one embodiment, the support structure may be configured to support the at least one switch body in such a way that the switch body is upright in a power-free state and makes a lateral compensation movement in the presence of a force acting on at least one of the coupling surfaces. An upright orientation of the switching body corresponds to a parallelism of the longitudinal axis of a respective switching body to corresponding longitudinal axes of the coupling body movably coupled together by means of the bearing device or to longitudinal axes of the other switching body. In other words, in this upright state, the connecting pins are oriented with their longitudinal axes parallel to one another and perpendicular to coupling planes, which are defined by the maximum longitudinally projecting areas of the convex coupling surfaces. By a lateral compensating movement, in particular a tilt, the switching body takes place in response to a transverse force of one of the coupling body, a sufficiently flexible storage while maintaining the power transmission function is possible.

 According to one exemplary embodiment, the support structure may be configured to support the at least one switching body in such a way that the switching body is returned to its upright position after a lateral compensating movement has been eliminated when the force acting on at least one of the coupling surfaces is removed. According to this embodiment, the support structure may be designed to exert a respectively restoring or restoring force on a temporarily tipped as a result of the force of one or both of the coupling body mediation body. A bearing axis of the switching body in the support structure can each correspond to a pivot point of the respective switching body. In this way, after elimination of a coupling body force, the bearing device can be automatically returned to an equilibrium state, whereby the bearing device is returned to a capable of receiving a coupling body force state again.

According to one embodiment, the support structure may be at least partially elastic Matrix may be formed, in which the at least one switching body is embedded. For example, the support structure may be a body of elastic material, such as elastic plastic, gel or rubber. It is also possible to provide the support structure of a rigid material and to elastically couple the transfer bodies to the rigid material by means of one or more spring elements or other elastic bodies (such as rubber elements). In the latter exemplary embodiment, the support structure has at least one spring which is designed to act on the at least one switching body and is coupled to the at least one switching body

 According to one embodiment, the bearing device may be formed as a two-dimensional planar bearing. The bearing apparatus according to this embodiment may be along an X-direction and a Y-direction orthogonal thereto, i. in the XY plane, the desired power transmission and the desired tilt compensation accomplish. A Z-direction orthogonal to the X-direction and the Y-direction may correspond to a connection axis of the coupling bodies. This can be realized by a two-dimensional arrangement of several switching bodies.

 According to one embodiment, the bearing device on the one hand and the first coupling body or the second coupling body on the other hand, at least partially rigidly connected to each other, for example, be formed integrally with each other. For example, the bearing device can seamlessly connect to an end portion of the first coupling body and at the projecting at a free end second coupling surface in operative connection with the second coupling body (or vice versa) to make there a load balance between the coupling bodies.

 According to an alternative embodiment, the bearing device can be arranged freely (in particular unsecured on both sides) between the first coupling body and the second coupling body. Thus, the bearing device can be formed separately from both the first coupling body and from the second coupling surface and can be clearly attached as a separate component between the two coupling bodies. The bearing device and one of the coupling body thus need not necessarily be rigidly coupled together. The one or more pins can also be freely between the two coupling bodies, so piston and drive, and are held in position, for example by means of spring forces.

 According to one embodiment, at least one of the piston and the actuator of the fluid pump may have a convex (in particular spherical) or a planar interface with the bearing device. For example, one of the coupling bodies may have a flat boundary surface and the other coupling body may have a convexly curved interface. The respective interface can then attack on a respective protruding convex coupling surface of the switching body. By combining a planar interface of one of the coupling bodies and a convex boundary surface of the other coupling body, it is possible to achieve a force transmission between the two coupling bodies that is particularly free of lateral forces by means of the bearing device.

 According to one embodiment, the fluid pump may comprise as a high pressure pump for pumping mobile phase to a separator of the sample separator for separating different fractions of a mobile phase fluid sample. Such a high pressure pump delivers mobile phase (especially a solvent composition) from one or more liquid containers to a sample separator such as a chromatographic separation column. At an injector device, the pumped mobile phase is then mixed with the fluidic sample. Since such a high-pressure pump may be exposed to high and highest pressures of 1200 bar and more, power-saving transmission of drive energy from a motor-driven actuator (for example, the mandrel of a ball screw, which mandrel is moved longitudinally by a motor-driven rotating nut) to a piston foot of one Pistons especially important.

 According to another embodiment, the fluid pump may be configured as a metering pump for pumping a fluidic sample in an injector for supplying the fluidic sample to mobile phase upstream of a separation device of the sample separation device for separating different fractions of the mobile phase fluid sample. Such a metering pump is used for metering a certain amount of fluidic sample into a so-called sample loop, the fluid sample drawn onto the sample loop subsequently being introduced by means of the same metering pump through a fluid valve of an injector device into a fluidic path between the high-pressure pump described above and the separator.

 One or both of the pump types of a liquid chromatography apparatus described can be equipped with the bearing device according to the invention between the piston and the actuator.

According to one embodiment, the sample separation device can be used as a chromatographic separation device, in particular as Chromatographietrennsäule be formed. In a chromatographic separation, the chromatographic separation column may be provided with an adsorption medium. At this, the fluidic sample can be stopped and only then fractionally dissolved again in the presence of a specific solvent composition, whereby the separation of the sample is accomplished in their fractions.

 The sample separation device may be a microfluidic measuring device, a life science device, a liquid chromatography device, a high performance liquid chromatography (HPLC), an UHPLC device, an SFC (Supercritical Liquid Chromatography) device, a gas chromatography device, an electrophoresis device, and / or a gel electrophoresis device , However, many other applications are possible.

 For example, the fluid pump may be configured to convey the mobile phase through the system at a high pressure, for example, from a few hundred bars up to 1000 bars or more.

 The sample separator may include a sample injector for introducing the sample into the fluidic separation path. Such a sample injector may comprise a syringe-dockable injection needle in a corresponding fluid path, which needle may be withdrawn from that seat to receive sample, wherein upon reintroduction of the needle into the seat, the sample is in a fluid path which, for Example, by switching a valve, can be switched into the separation path of the system, which leads to the introduction of the sample in the fluidic separation path.

 The sample separator may include a fraction collector for collecting the separated components. Such a fraction collector may carry the various components, for example, into different liquid containers. The analyzed sample can also be fed to a drain tank.

 Preferably, the sample separation device may comprise a detector for detecting the separated components. Such a detector may generate a signal which can be observed and / or recorded and which is indicative of the presence and amount of sample components in the fluid flowing through the system.

BRIEF DESCRIPTION OF THE FIGURES

 Other objects and many of the attendant advantages of embodiments of the present invention will be readily appreciated and become better understood by reference to the following more particular description of embodiments taken in conjunction with the accompanying drawings. Features that are substantially or functionally the same or similar are given the same reference numerals.

1 shows an HPLC system according to an exemplary embodiment of the invention.

2 shows a fluid pump of a sample separator according to an exemplary embodiment of the invention, in which between a piston as the first coupling body and an actuator as a second coupling body, a bearing device is arranged cylindrical pins with opposite spherical coupling surfaces.

3A and 3B show two different configurations of the storage device according to 2 and in particular each show an enlargement of an interface between the first coupling body and the second coupling body mediated by the bearing device 2 ,

4 and 5 FIG. 3 each shows a three-dimensional view and a cross-sectional view of a bearing device according to an exemplary embodiment of the invention of a plurality of switching bodies embedded in an elastic matrix, which are formed as cylindrical switching pins with spherical top and bottom surfaces.

6 shows a schematic drawing as a basis for an auxiliary idea, which demonstrates the space savings of a training of a storage device according to an exemplary embodiment of the invention in comparison with a conventional ball bearing assembly.

7 shows a spatial view of a switching body of a storage device according to an exemplary embodiment of the invention.

8th shows another switching body of a storage device according to an exemplary embodiment of the invention.

 The illustration in the drawing is schematic.

Before describing exemplary embodiments with reference to the figures, some basic considerations will be summarized based on which exemplary embodiments of the invention have been derived.

According to an exemplary embodiment of the invention, there is provided a compact two-dimensional bearing apparatus having a high mechanical load capacity mounted in a fluid pump.

 Mechanical decoupling (in terms of axial offset and axis drift and axle tilt) between a piston root and a drive to provide axial drive force to a piston is advantageous in piston driven high pressure pumps (for example, for chromatography applications). Conventionally, this requirement is solved by placing a steel ball between the two planes, whereby an offset correction (by rolling) and a tilt compensation is achieved. However, such a solution reaches its limits with increased load requirements of fluid pumps with greatly increased pressure values. Higher axial forces would require larger ball radii, which would lead to an axle extension. This, in turn, would undesirably increase the dimensions of the entire fluid pump.

 While tilt compensation is achievable by implementing a simple level-to-ball contact, the radius of the ball must be large enough to provide a moderate contact pressure. On the other hand, the axis offset and the drift compensation remain challenging problems.

 In order to achieve axial offset and drift compensation according to an exemplary embodiment (leaving the concept of a large radius ball for tilt compensation to be considered), an array of cylindrical bodies with axially spherical end segments (ie, pins with concentric rounded ends) is provided the arrangement is arranged between two support levels, and wherein the pin axes are all parallel to each other and aligned vertically to the planes.

 Such an arrangement is capable of providing clearance-neutral support in an XY plane operable for displacements of a size approximately equal to the radius of the pins. For example, at an appropriate height as in a conventional ball bearing, such switch bodies may have an increased load capacity relative to the necessary area increased by a factor corresponding to the number of pins used. The number of pins used is limited by a necessary diameter of a pin (determined by maximum axis offset, maximum drift and tolerances such that during operation the ends of the connection pins do not roll out of their spherical surfaces) and the total available area of the support planes. Thus, for specific use in high pressure fluid pumps, a large increase in the maximum tolerable load can be achieved compared to a single ball bearing. The overall assembly height may even be smaller than that of a corresponding ball bearing, because a small pinender radius (in particular a half pin height) can be used, compensated by a larger number of pins.

 The connection pins can be arranged in an elastic support structure as a support, for example a polymer mesh or one or more independent or interconnected elastic plates, etc., which can ensure an initial parallel orientation of the connection pins. One or both of the support planes may or may have a convex outer surface or plane and / or be contacted by a convex surface of the counterpart to achieve axis tilt compensation.

 It will be understood by one of ordinary skill in the art that a fluid pump bearing apparatus according to an exemplary embodiment of the invention may be advantageous for any fluid pump application requiring two-dimensional support which requires compact offset-neutral high-load offset compensation. A fluid pump for a sample separator can be operated efficiently and component-friendly.

1 shows the basic structure of an HPLC system 10 , as it can be used for example for liquid chromatography. A fluid pump 20 as a fluid drive device with solvents from a supply unit 25 supplied drives a mobile phase through a sample separator 30 (such as a chromatographic column) containing a stationary phase. A degasser 27 can degas the solvents before these the fluid pump 20 be supplied. An optional sample application unit 40 is between the fluid pump 20 and the sample separator 30 arranged to introduce a sample liquid in the fluidic separation path. The stationary phase of the sample separator 30 is intended to separate components of the sample. A detector, see flow cell 50 , detects separated components of the sample, and a fractionator may be provided to dispense separated components of the sample into dedicated containers. Liquids no longer needed can drain into a drain 60 be issued.

A control unit 70 controls the individual components 20 . 25 . 27 . 30 . 40 . 50 . 60 of the sample separator 10 ,

2 shows a cross-sectional view of a fluid drive of a fluid pump 20 according to an exemplary embodiment of the invention, with a bearing device 200 is provided.

The fluid pump 20 , from a pump base 250 and an associated pump head 260 formed, has a piston chamber 210 on, inside of which there is a working room 212 is limited. In the workroom 212 in the pump chamber 210 is a piston as the first coupling body 202 for reciprocating along a 2 arranged horizontally. By reciprocating or reciprocating the piston in the piston chamber 212 becomes fluid from a fluid inlet 214 under high pressure to a fluid outlet 216 promoted. A seal 218 seals the first coupling body 202 opposite the piston chamber 210 from. A support device 271 , in the 2 is shown only schematically supports or holds the seal 218 in place, to prevent the seal 218 by the prevailing pressure in the environment from the workroom 212 is pushed out.

The first coupling body 202 is by means of the storage device 200 with an actuator as the second coupling body 204 positively coupled. A drive device 238 , which may be formed, for example, as an electric motor, a drive shaft 220 rotatably drive. The drive shaft 220 is, for example using two cooperating gears, with a nut 222 a ball screw shown by way of example coupled. Thus, the drive means displaces 238 the mother 222 in rotation. The mother 222 in turn transmits the driving force to the actuator, that this in accordance with 2 reciprocated horizontally, that is, moving from left to right and back again. As an alternative to the described configuration, it is generally possible to implement in another way an actuator moved back and forth by a drive. As a result, the actuator drives as a second coupling body 204 the piston as the first coupling body 202 for reciprocating in the piston chamber 212 at. 2 further shows schematically a spring 279 , which is tensioned as the actuator advances, and for moving the piston out of the working space 212 contributes when the actuator moves backwards.

In this drive mechanism, it can lead to an axial offset or to an axial tilt between the first coupling body 202 and the second coupling body 204 come. In order to absorb or compensate for associated mechanical stresses, is between the first coupling body 202 and the second coupling body 204 the storage device 200 arranged according to an exemplary embodiment of the invention.

The storage device 200 serves to mediate a force between the first coupling body 202 and the second coupling body 204 and has a plurality of respective rigid but flexibly mounted switching bodies 206 on. The storage device 200 can be a support structure 208 in which the switching bodies 206 are elastically embedded and supported. The structure of each of the switching bodies is based on 3A . 3B closer.

3A and 3B show, for two different configurations, a detailed view of the respective storage device 200 between the first coupling body 202 and the second coupling body 204 , Each of the mediation bodies 206 has a closed cap-shaped spherical first coupling surface 300 (ie with the shape of a ball cap) for coupling to a plane interface here 320 of the first coupling body 202 , This coupling is according to 3A and 3B directly, so that the coupling surface 300 the interface 320 touched. On an opposite side of the storage device 200 Everyone has the mediation body 206 one of the spherical first coupling surface 300 opposite closed cap-shaped spherical second coupling surface 302 (ie also with the shape of a ball cap) for coupling to a corresponding, according to 3A convex and according to 3B plane interface 322 of the second coupling body 204 , This coupling is according to 3A and 3B indirectly, so that the coupling surface 302 the interface 322 not directly touched, but instead from the interface 322 through a rigid housing body 399 physically separated, but actively coupled. Each of the mediation bodies 206 has between the two spherical coupling surfaces 300 . 302 a circular cylindrical connection pin 304 , Illustratively, each of the mediation bodies 206 be machined out of a sphere, for this purpose between the two spherical coupling surfaces 300 . 302 laterally material would have to be removed to form there from the ball geometry a circular cylinder geometry. Both according to 3A as well as according to 3B The connecting pins are supported 304 on both sides on flat surfaces. A possibly curved surface can either by interface 322 of the second coupling body 204 (please refer 3A ) or by an outside surface 397 of the housing body 399 (please refer 3B ) are given. The other of the two adjacent surfaces on the right side 397 . 322 can be even.

In this way they form over the support structure 208 on both sides excellent spherical coupling surfaces 300 . 302 a respective effective coupling plane for transmitting force between the first coupling body 202 and the second coupling body 204 More precisely, from the second coupling body 204 on the first coupling body 202 , The spherical geometry of the contact or coupling surfaces 300 . 302 leads to a low tipping susceptibility of the individual switching bodies 206 during power transmission. This is promoted by the fact that a maximum distance d between opposing coupling surfaces 300 . 302 just corresponds to the diameter of the virtual sphere, on the surface of both coupling surfaces 300 . 302 lie and opposite which the connection pin 304 has a reduced volume, a reduced mass and a reduced space requirement.

The support structure 208 supports the mediation bodies 206 such that the respective first coupling surface 300 and the respective second coupling surface 302 on both sides opposite the support structure 208 stand out and that the individual connection pins 304 the mediation body 206 are arranged parallel to each other in a power-free state. For example, by an axial displacement force and / or a tilting force between the two coupling bodies 202 . 204 can be initiated on the mediation body 206 during operation of the fluid pump 20 to exert a force. In this scenario, the mediation bodies perform 206 a compensating movement by tilting out of its axially parallel position in order to perform a displacement force force-free or almost force-free or neutral force and yet the power transmission between the coupling bodies 202 . 204 maintain. On the other hand, the mediation bodies 206 such in the support structure 208 stored that after completion of the tilting movement to compensate for the offset movement under the action of a restoring force are returned to their original position with mutually parallel axis positions. The support structure 208 For this purpose, for example, may be wholly or partly made of an elastic material (for example, a flexible rubber, gel or plastic, or using springs), by storage of the switching bodies 206 to exercise the restoring force described.

4 shows a three-dimensional view and a cross-sectional view of a bearing device 200 according to an exemplary embodiment of the invention, in the total 19 (= 1 + 6 + 12) mediation body 206 in an elastic support structure 208 are arranged as a recording matrix. An external rigid bracket 400 (for example, metal or plastic) serves as a mounting base for the support structure 208 and the mediation bodies 206 and ensures stability and protection of the mediation bodies 206 and the support structure 208 in the circumferential direction. The holder 400 can - optionally - as the end of one of the two coupling body 202 . 204 be educated. According to 4 are a central mediating body 206 around six more mediation bodies 206 arranged in a ring, which in turn consists of eighteen other switching bodies 206 are surrounded annularly. This is by providing a large number of exchanges 208 To transmit large forces a dense packing and thus created a compact arrangement, the highest pressures in fluid pumps 20 can withstand. 4 also shows a cross-sectional view of the bearing device 200 which shows that the supporting body formed of an elastic material 208 Has cavities to the freedom of movement of the switching body 206 only slightly disturbing.

5 shows a three-dimensional view and a cross-sectional view of a bearing device 200 according to another exemplary embodiment of the invention, in which, unlike 4 the entire space between the exchanges 206 from the elastic material of the support body 208 is surrounded. The supporting body 208 is thus between the mediation bodies 206 made of solid material and free of cavities.

Based on 6 Beyond advantages of a storage device 200 described according to an embodiment of the invention over a simple ball. 6 illustrates again in the form of two here flat interfaces 320 . 322 not shown coupling bodies 202 respectively. 204 like a mediation body 206 the storage device 200 between two such interfaces 320 . 322 can be arranged. Active surfaces of the switching body 206 , that is spherical end faces as coupling surfaces 300 . 302 are at the ends of a circular cylindrical connecting pin 304 educated. It is further shown that the spherical surfaces of the coupling surfaces 300 . 302 diametrically opposite segments of one and the same ball 600 with a radius r. Opposite such a virtual and therefore in 6 only dashed (comparative) sphere 600 is at the mediation body 206 laterally omitted material to the non-spherical, here circular cylindrical connection pin 304 to design. In this way, the storability of the switching body 206 as good as those of a corresponding sphere 600 , but with significantly reduced space requirement in an XY plane orthogonal to the transmission force in the Z direction. This means that compared to a ball a significantly increased number of operator bodies 206 between the interfaces 320 . 322 the in 6 Not shown coupling body 202 . 204 can be arranged, whereby the per unit area absorbable axial forces can be significantly increased. Alternatively, a storage device set up to receive the same forces 200 be made significantly more compact according to the invention than with a corresponding conventional ball bearing. 7 shows that the two spherical coupling surfaces 300 . 302 at opposite ends of the switch body 206 not necessarily concentric, but, as in 7 shown, may be further apart or (not shown in the figures) may also be closer together (in the latter case would be in 7 drawn parameter Δ negative). In the case of Δ = 0, these are the mediation bodies 206 acting bearing forces particularly low, at a negative value of Δ is the bearing device 200 particularly compact in the axial direction.

8th shows a switch body 206 according to another exemplary embodiment of the invention, in which the two coupling surfaces 300 . 302 on balls of the same center 800 but different radii r ₁ , r ₂ are. Thus, for example, a force transmission between two different sized interfaces 320 . 322 different sized coupling body 202 . 204 be done (especially if a single body is used). It can be the smaller coupling surface 300 of the mediation body 206 be provided from a harder material than the larger coupling surface 302 or be provided with a hardening coating.

 It should be noted that the term "comprising" does not exclude other elements and that the "on" does not exclude a plurality. Also, elements described in connection with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• EP 0309596 B1 [0002]
• US 5415489 [0005]
• US 5887507 [0006]

Claims (20)

Fluid pump ( 20 ) for pumping fluid in a sample separation device ( 10 ), wherein the fluid pump ( 20 ) comprises: a piston as the first coupling body ( 202 ), which is capable of reciprocating in a piston chamber for conveying fluid ( 210 ) is arranged; an actuator as a second coupling body ( 204 ) for transmitting a force for driving the piston in the piston chamber (US Pat. 210 ) is arranged; a storage device ( 200 ) for conveying a force between the first coupling body ( 202 ) and the second coupling body ( 204 ), the storage device ( 200 ) at least one mediation body ( 206 ), wherein the mediation body ( 206 ) has a cap-shaped convex first coupling surface ( 300 ) for coupling to the first coupling body ( 202 ); one of the first coupling surface ( 300 ) opposite cap-shaped convex second coupling surface ( 302 ) for coupling to the second coupling body ( 204 ); and a connection pin ( 304 ) between the first coupling surface ( 300 ) and the second coupling surface ( 302 ). Fluid pump ( 20 ) according to claim 1, wherein the first coupling surface ( 300 ) has a spherical surface segment and / or the second coupling surface ( 302 ) has a spherical surface segment. Fluid pump ( 20 ) according to claim 2, wherein a maximum length of the switching body ( 206 ) between the first coupling surface ( 300 ) and the second coupling surface ( 302 ) equal to a sum of a radius of the spherical surface segment of the first coupling surface ( 300 ) and a radius of the spherical surface segment of the second coupling surface ( 302 ). Fluid pump ( 20 ) according to one of claims 1 to 3, wherein the mediation body ( 206 ) opposite to a virtual sphere with a diameter which is a maximum distance between the first coupling surface ( 300 ) and the second coupling surface ( 302 ), has reduced volume. Fluid pump ( 20 ) according to one of claims 1 to 4, wherein the connecting pin ( 304 ) in the direction between the first coupling surface ( 300 ) and the second coupling surface ( 302 ) is limited in cross-section by non-spherical, in particular rectilinear, boundary lines. Fluid pump ( 20 ) according to one of claims 1 to 5, wherein the storage device ( 200 ) a plurality of switching bodies ( 206 ) according to one of claims 1 to 5, in particular such that their connecting pins ( 304 ) are arranged in a power-free state parallel to each other. Fluid pump ( 20 ) according to one of claims 1 to 6, wherein the storage device ( 200 ) a number

of mediation bodies ( 206 ) according to any one of claims 1 to 6, wherein n is zero or a whole positive number. Fluid pump ( 20 ) according to one of claims 1 to 7, wherein the storage device ( 200 ) a support structure ( 208 ), in which the at least one switching body ( 206 ) is arranged supporting. Fluid pump ( 20 ) according to claim 8, wherein the support structure ( 208 ) is formed, the at least one switching body ( 206 ) in such a supporting manner that the respective first coupling surface ( 300 ) and / or the respective second coupling surface ( 302 ) opposite the support structure ( 208 protruding or protruding. Fluid pump ( 20 ) according to claim 8 or 9, wherein the support structure ( 208 ) is formed, the at least one switching body ( 206 ) in such a supporting manner that the mediation body ( 206 ) is oriented upright in a force-free state and in the presence of at least one of the coupling surfaces ( 300 . 302 ) acting force performs a lateral compensation movement. Fluid pump ( 20 ) according to claim 10, wherein the support structure ( 208 ) is formed, the at least one switching body ( 206 ) in such a supporting manner that the mediation body ( 206 ) after completion of the lateral compensation movement in the absence of at least one of the coupling surfaces ( 300 . 302 ) acting force is returned to its upright position. Fluid pump ( 20 ) according to one of claims 8 to 11, further comprising at least one of the following features: the support structure ( 208 ) is formed as at least partially elastic matrix into which the at least one switching body ( 206 ) is embedded; the support structure ( 208 ) has at least one spring which, for acting on the at least one switching body ( 206 ) and with the at least one switching body ( 206 ) is coupled. Fluid pump ( 20 ) according to one of claims 1 to 12, further comprising at least one of the following features: the storage device ( 200 ) is designed as a two-dimensional planar bearing; the at least one mediation body ( 206 ) is in one piece, in particular einstoffig, formed; an outer surface of the connecting pin ( 304 ) between the first coupling surface ( 300 ) and the second coupling surface ( 302 ) is circular cylindrical or polygonal, in particular hexagonal; the connection pin ( 304 ) has along a longitudinal axis between the first coupling surface ( 300 ) and the second coupling surface ( 302 ) has a constant cross section. Fluid pump ( 20 ) according to one of claims 1 to 13, further comprising one of the following features: the storage device ( 200 ) and one of the first coupling body ( 202 ) and the second coupling body ( 202 ) are at least partially rigidly connected to each other, in particular integrally formed with each other; the storage device ( 200 ) is free between the first coupling body ( 202 ) and the second coupling body ( 202 ) arranged. Fluid pump ( 20 ) according to one of claims 1 to 14, wherein at least one of the piston and the actuator has a convex, in particular spherical, or planar interface ( 320 . 322 ) to the storage device ( 200 ) having. Fluid pump ( 20 ) according to one of claims 1 to 15, comprising one of the following features: the fluid pump ( 20 ) is used as a high pressure pump for pumping mobile phase to a separator ( 30 ) of the sample separation device ( 10 ) for separating different fractions of a mobile phase fluidic sample; the fluid pump ( 20 ) is used as a metering pump for conveying a fluidic sample in an injector ( 40 ) for supplying the fluidic sample to mobile phase upstream of a separator ( 30 ) of the sample separation device ( 10 ) for separating different fractions of the fluid phase sample in the mobile phase. Sample Separator ( 10 ) for separating a mobile phase fluidic sample into fractions, wherein the sample separation device ( 10 ) comprises: a fluid pump ( 20 ) according to one of claims 1 to 16, configured for driving at least one of the mobile phase and the fluidic sample through the sample separation device ( 10 ); a separator ( 30 ) downstream of the fluid pump ( 20 ) for separating the different fractions of the sample in the mobile phase. Sample Separator ( 10 ) according to claim 17, further comprising at least one of the following features: the sample separation device ( 30 ) is designed as a chromatographic separation device, in particular as a chromatography separation column; the sample separator ( 10 ) is configured to analyze at least one physical, chemical and / or biological parameter of at least one fraction of the fluidic sample; the sample separator ( 10 ) comprises at least one of the group consisting of a detector device, a chemical, biological and / or pharmaceutical analysis device, a liquid chromatography device and an HPLC device; the fluid pump ( 20 ) is configured to drive the mobile phase at a high pressure; the fluid pump ( 20 ) is configured to drive the mobile phase at a pressure of at least 100 bar, in particular of at least 500 bar, more particularly of at least 1000 bar; the sample separator ( 10 ) is configured as a microfluidic device; the sample separator ( 10 ) is configured as a nanofluidic device; the sample separator ( 10 ) has an injector device ( 40 ) for introducing the fluidic sample, the fluidic path between the fluid pump ( 20 ) and the sample separation device ( 30 ) on; the sample separator ( 10 ) has a detector ( 50 ) for detecting the separated fractions; the sample separator ( 10 ) has a sample fractionator ( 60 ) to fractionate the separated fractions. Method for producing a storage device ( 200 ) for transmitting a force between a piston as a first coupling body ( 202 ) and an actuator as a second coupling body ( 204 ), the method comprising: forming the bearing device ( 200 ) with at least one mediation body ( 206 ); Forming the at least one switch body ( 206 ) with a cap-shaped convex first coupling surface ( 300 ) for coupling to the first coupling body ( 202 ); Forming the at least one switch body ( 206 ) with one of the first coupling surface ( 300 ) opposite cap-shaped convex second coupling surface ( 302 ) for coupling to the second coupling body ( 204 ); and providing a connection pin ( 304 ) between the first coupling surface ( 300 ) and the second coupling surface ( 302 ). The method of claim 19, further comprising manufacturing a fluid pump ( 10 ) for pumping fluid in a sample separation device ( 10 ) under Use of the storage device ( 200 ) between the piston and the actuator of the fluid pump ( 10 ).

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