Beverage pump

Abstract

The invention relates to a beverage pump, in particular an oscillating piston pump, for a household appliance (12a), in particular for a beverage vending machine, for conveying a liquid, with at least one coil carrier (14a; 14b), at least one coil wire which is wound on the coil carrier (14a; 14b) to form a coil (16a; 16b), with a working piston (18a; 18b), with a pumping chamber (20a; 20b), in which the working piston (18a; 18b) is guided in an axially movable manner, which, with a mounted working piston (18a; 18b), has a pre-chamber (22a; 22b), a pressure chamber (24a; 24b) and an outlet chamber (26a; 26b) and which has a piston guide (28a; 28b), with a magnetic actuator (30a; 30b) which is provided to generate a magnetic field for driving the working piston (18a; 18b), and with an outlet valve (32a; 32b) which is fluidically connected between the pressure chamber (24a; 24b) and the outlet chamber (26a;26b) and which has at least one compression chamber unit (34a; 34b) with a compression chamber housing (36a; 36b), and at least one valve element (38a; 38b). ; It is proposed that the piston guide (28a; 28b) and / or the compression chamber housing (36a; 36b) be free of glass fibers.

Description

Prior ArtThe invention relates to a beverage pump.A beverage pump, in particular a swing piston pump, for a domestic appliance, in particular for a beverage machine, for conveying a liquid, has already been proposed, having at least one coil carrier, at least one coil wire which is wound onto the coil carrier to form a coil, having a working piston, having a pump chamber in which the working piston is guided in an axially movable manner, which pump chamber, when the working piston is mounted, has a pre-chamber, a pressure chamber and an outlet chamber and which has a piston guide, having a magnetic actuator which is provided for providing a magnetic field for driving the working piston, and having an outlet valve which is arranged in terms of flow between the pressure chamber and the outlet chamber and which has at least one compression chamber unit having a compression chamber housing, and at least one valve element.The object of the invention is in particular to provide a device of the generic type having improved properties with regard to sustainability, in particular a recycling capability and / or a circulatory management capability. The object is achieved according to the invention by the features of claim 1, while advantageous embodiments and developments of the invention can be found in the dependent claims.Advantages of the InventionThe invention is based on a beverage pump, in particular a swing piston pump, for a domestic appliance, in particular for a beverage machine, for conveying a liquid, having at least one coil carrier, at least one coil wire which is wound onto the coil carrier to form a coil, having a working piston, having a pump chamber in which the working piston is guided in an axially movable manner, which pump chamber, when the working piston is mounted, has a pre-chamber, a pressure chamber and an outlet chamber and which has a piston guide, having a magnetic actuator which is provided for providing a magnetic field for driving the working piston, and having an outlet valve which is arranged in terms of flow between the pressure chamber and the outlet chamber and which has at least one compression chamber unit having a compression chamber housing, and at least one valve element.It is proposed that the piston guide and / or the compression chamber housing is free of glass fibers. Preferably, the piston guide and / or the compression chamber housing is free of a glass fibre reinforced plastic. Particularly preferably, the piston guide and / or the compression chamber housing is free of a composite material. Glass fibers, in particular in a composite material, prevent in particular a reasonable recycling capability and / or a circulation management capability. However, glass fibers are generally required in particular in order to achieve sufficient mechanical stability and / or thermal stability. The configuration of the beverage pump according to the invention can improve in particular the recycling capability of the beverage pump. Materials which are difficult or not recyclable can in particular be dispensed with or at least reduced. As a result, an ecological footprint of the beverage pump can in turn be advantageously kept low. Furthermore, the beverage pump can enable in particular a full circulation management capability. In particular, parts of the beverage pump can be reused. In particular, the piston guide and / or the compression chamber housing can advantageously be used for a plurality of beverage pumps.In this context, a "beverage machine" is to be understood to mean, in particular, a machine which is provided for the portionwise dispensing and / or preparation of beverages, such as coffee, tea, cocoa and / or other mixed milk beverages and / or brewing beverages. The beverage machine is preferably designed as a coffee machine, preferably as a fully automatic coffee machine. The beverage pump is preferably designed as a swing piston pump. The beverage pump preferably has at least one floatingly mounted working piston which is provided to be driven in particular by a magnetic flux conducted by a pole sleeve. In particular, the working piston is provided for a stop-free movement in the pump chamber. Preferably, the working piston is provided for a movement at least substantially parallel to a central axis of the pole sleeve. The beverage pump is preferably designed as a high-pressure oscillating piston pump and is provided to provide a pressure of at least 10 bar, preferably of at least 15 bar. It is also conceivable for the beverage pump to be designed as a low-pressure oscillating piston pump and to be provided to provide a pressure of at least 3 bar. In particular, the beverage pump is designed as a domestic appliance oscillating piston pump. The beverage pump is preferably designed as a beverage automatic pump. The beverage pump preferably has an iron circuit which comprises two pole sleeves. Preferably, the pole sleeves are at least substantially tubular. The pole sleeve preferably has the shape of a hollow cylinder and a central axis. The pole sleeve surrounds the pump chamber. Preferably, the pole sleeve is arranged outside the pump chamber. In particular, the beverage pump has a pump chamber in which the working piston is guided. Directional designations such as "axial", "radial", "in the circumferential direction" are to be understood with reference to a central axis of the pump chamber and / or with reference to the central axis of the pole sleeve. The term "axially" is to be understood as meaning in the direction of the central axis of the pump chamber and / or in the direction of the central axis of the pole sleeve. In this context, "radially" is to be understood to mean, in particular, a direction perpendicular to the central axis of the pole sleeve and / or perpendicular to the central axis of the pump chamber, starting from the respective central axis toward the outside. In this context, "in the circumferential direction" is to be understood as meaning, in particular, a curve along a circular arc around the central axis of the pole sleeve and / or around the central axis of the pump chamber in a plane perpendicular to the central axis of the pole sleeve and / or perpendicular to the central axis of the pump chamber.The piston guide forms in particular a base body of the pump chamber. The piston guide preferably has a hollow cylindrical basic shape. The piston guide is provided in particular for direct guidance of the working piston. The pole sleeves are preferably arranged directly adjacent to the piston guide. Preferably, the pole sleeves are arranged around the piston guide.The outlet valve forms in particular a nonreturn valve which has a throughflow direction from the pressure chamber to the outlet chamber. Preferably, the outlet valve also comprises a spring element which, in an assembled state, presses the valve element against a valve seat of the compression chamber unit, in particular the compression chamber housing. The spring element is formed in particular by a helical spring. The valve element is formed in particular by a movable, closing part of the outlet valve. The valve element forms in particular a valve body. Various embodiments of the valve element that appear expedient to a person skilled in the art are conceivable. The valve element is guided in particular in the compression chamber unit. The valve element is guided in particular in the compression chamber housing. Furthermore, the compression chamber housing forms in particular a valve seat for the valve element. "Provided" is to be understood in particular as being specially programmed, designed and / or equipped. The fact that an object is provided for a specific function is to be understood in particular to mean that the object fulfills and / or executes this specific function in at least one application state and / or operating state.It is furthermore proposed that the piston guide consists at least partially, in particular completely, of a homogeneous material. Preferably, the piston guide is free of composite materials. Preferably, the piston guide is made entirely of a homogeneous material, such as a metal material or a plastic. In this context, a "homogeneous material" is to be understood as meaning, in particular, a material of continuously uniform composition or a material consisting of different materials, the different materials being mixed homogeneously with one another. Preferably, this is to be understood as meaning, in particular, a material of continuously uniform composition. As a result, in particular, a recycling capability of the beverage pump can be advantageously kept high. Materials which are difficult or not recyclable can in particular be dispensed with or at least reduced.Furthermore, it is proposed that the piston guide consists at least partially of a metal material. Preferably, the piston guide consists at least partially, in particular completely, of a metal alloy. Preferably, the piston guide consists at least partially, in particular completely, of stainless steel. However, other materials that appear expedient to a person skilled in the art are also conceivable. In this way, in particular an advantageously reusable and / or recyclable piston guide can be provided. In particular, recycling of a grade-free material can be made possible.It is further proposed that the piston guide is formed by a deep-drawn part. Preferably, the piston guide is produced by means of deep drawing. The piston guide is preferably formed by a deep-drawn sleeve. In this way, in particular an advantageously reusable and / or recyclable piston guide can be provided. In particular, recycling of a grade-free material can be made possible. Known piston guides are manufactured in particular from glass fiber-reinforced plastic.It is further proposed that the piston guide has a base body made of a plastic and at least one reinforcing sleeve made of a metal material. The piston guide is preferably designed at least in two parts. The base body and the reinforcing sleeve are connected to one another in particular in a form-fit and / or force-fit manner and are free of a material bond. However, it would also be conceivable for the base body and the reinforcing sleeve to be connected to one another at least partially in a materially bonded manner. It would be conceivable in particular for the base body to be formed by injection molding onto the reinforcing sleeve. Alternatively, it would also be conceivable for the base body to be produced, for example, by means of an additive method, such as 3D printing, for example. By "connected in a form-fitting and / or force-fitting manner" is herein in particular a releasable connection to be understood, wherein a holding force between two components is preferably transmitted by a geometrical engagement of the components in one another and / or a frictional force between the components. By "positively locking" is to be understood in particular that mutually adjacent surfaces of components connected positively to one another exert a holding force on one another which acts in the normal direction of the surfaces. In particular, the components are in a geometric engagement with one another. In this way, in particular an advantageously stable piston guide, which in spite of all is easy to recycle, can be provided. In particular, a simple and clear separation of material can be made possible. In particular, a mixing of materials can be avoided.It is also proposed that the reinforcing sleeve is formed by an inner metal tube adjoining the base body. The metal tube preferably has a material thickness that is less than a material thickness of the base body. The base body preferably has a hollow cylindrical basic shape. A material thickness of the reinforcing sleeve is preferably less than 3 mm, preferably less than 2 mm and particularly preferably less than 1 mm. The pole sleeves are preferably arranged on the base body. However, it would also be conceivable for the pole sleeves to be arranged between the base body and the reinforcing sleeve or to be partially accommodated in the base body.It is furthermore proposed that the compression chamber housing consists partially, in particular completely, of a homogeneous material. Preferably, the compression chamber housing is free of composite materials. Preferably, the compression chamber housing is made entirely of a homogeneous material, such as a metal material or a plastic. As a result, in particular, a recycling capability of the beverage pump can be advantageously kept high. Materials which are difficult or not recyclable can in particular be dispensed with or at least reduced.Furthermore, it is proposed that the compression chamber housing consists at least partially of a metal material. Preferably, the compression chamber housing consists at least partially, in particular completely, of a metal alloy. Preferably, the compression chamber housing consists at least partially, in particular completely, of stainless steel. However, other materials that appear expedient to a person skilled in the art are also conceivable. In this way, in particular an advantageously reusable and / or recyclable compression chamber housing can be provided. In particular, recycling of a grade-free material can be made possible.It is further proposed that the compression chamber housing is formed by a deep-drawn part. Preferably, the compression chamber housing is produced by means of deep drawing. The compression chamber housing is preferably formed by a multistage deep-drawn sleeve which is provided for receiving at least one compression chamber inner part. Preferably, the compression chamber inner member directly defines the compression chamber, and the compression chamber housing receives the compression chamber inner member. In this way, in particular an advantageously reusable and / or recyclable compression chamber housing can be provided. In particular, recycling of a grade-free material can be made possible. Known compression chamber housings are manufactured in particular from glass fiber-reinforced plastic.It is further proposed that the compression chamber housing consists entirely of a plastic. Preferably, the compression chamber housing is made of a homogeneous plastic. The compression chamber housing preferably has an increased wall thickness. The compression chamber housing preferably has an increased wall thickness compared to a conventional compression chamber housing. Preferably, the compression chamber housing has an average wall thickness of at least 1.5 mm, preferably at least 2 mm and particularly preferably at least 2.5 mm. Particularly preferably, the compression chamber housing and the compression chamber inner part consist of a plastic. The plastic preferably has a food conformity. In this way, in particular a compression chamber housing which is advantageously easy to produce can be provided. In particular, recycling of a grade-free material can be made possible.It is furthermore proposed that the valve element consists partially, in particular completely, of glass. The valve element is mounted in particular movably in the compression chamber housing, in particular in the compression chamber inner part. Preferably, the valve element has a spherical shape. However, another form that appears expedient to a person skilled in the art would also be conceivable. Preferably, a material of the compression chamber housing, in particular of the compression chamber inner part, is adapted to the material of the valve element. Preferably, the material of the compression chamber housing, in particular of the compression chamber inner part, is softer, in particular softer and more elastic, than the material of the valve element, in order to avoid damage to the valve element. Furthermore, it is proposed that the valve element is formed by a glass ball. In this way, in particular an advantageously reusable and / or recyclable valve element can be provided. In particular, an advantageously long-lived valve element can be provided. Furthermore, in particular, recycling of a single type can be made possible.Furthermore, it is proposed that the coil carrier consists at least partially, in particular completely, of a homogeneous material. It is further proposed that the coil carrier consists partially, in particular completely, of glass. In particular, the coil carrier is at least partially cylindrical, in particular hollow cylindrical. In particular, the coil carrier surrounds at least one cavity which is provided for receiving a magnetic body, in particular the armature of a oscillating armature pump, and the piston guide. In particular, the coil is provided to generate a magnetic field at least in a current-operated state, which magnetic field is provided to move the magnetic body out of its rest position. In particular, the coil is of hollow cylindrical configuration. In particular, the coil is designed as a long coil, i.e. in particular has a length which is greater than an inner diameter of the coil. For example, the coil has between 1000 and 5000 turns. Preferably, the beverage pump further comprises a coil housing. A "coil housing" is to be understood in particular as a mechanical housing, in particular a housing. The coil housing preferably has at least one wall which is connected to the coil carrier in a positive and / or non-positive manner, and a yoke plate. Preferably, the wall is connected to the coil carrier in a mountable and / or detachable manner without tools. In particular, the wall and the base body are connected to one another by means of a snap connection. This allows simple assembly. The wall is preferably designed in the manner of a grid, in particular with holes and / or gaps. In particular, the wall is formed at least partially, for example to an extent of at least 50%, advantageously to an extent of at least 90%, from at least one plastic. The coil housing, in particular the at least one wall, advantageously has holes and / or gaps. Preferably, the holes and / or gaps each have a size which is at most 0.2 sr, advantageously at most 0.1 sr, preferably at most 0.05 sr, with respect to the geometrical center point of the coil. In particular, these holes and / or gaps serve for ventilating and / or cooling the coil. In particular, a proportion of the holes is at most 90%, for example at most 50%, in particular at most 30%, of a solid angle covered by the wall. In particular, the holes and / or the gaps each have a size of at most 2 cm 2, for example at most 1 cm 2, in particular at most 0.5 cm 2.Preferably, the coil housing, in particular the at least one wall, comprises a holder for receiving a thermal fuse, which is provided to arrange the thermal fuse in proximity to the coil, in particular in mechanical contact, with the coil. In particular, simple installation of the coil device can thus be achieved. Preferably, the coil device comprises the thermal fuse. In particular, the thermal fuse is provided to be connected in series with the coil. In particular, the thermal fuse is provided to interrupt or at least inhibit a current flow through the coil, in particular permanently, when a limit temperature is exceeded. In particular, the thermal fuse has a nonlinear resistor. In particular, the thermal fuse is designed as a fuse. Alternatively, the thermal fuse can have a switching element, in particular a half-switch switching element or a bimetallic switching element. In particular, the holder is provided to receive the thermal fuse in a form-fitting manner, in particular by means of at least one snap connection. Furthermore, the coil housing can have at least one diode holder for receiving a power diode, wherein the power diode is provided in particular for being connected in series with the coil. In particular, simple installation of the coil device can thus be achieved. Preferably, the coil device comprises the power diode. In particular, the power diode is provided to allow current flow through the coil only in one current direction, in particular in order to avoid deflection of the armature of the oscillating armature coil in an incorrect direction. In particular, the diode holder is provided to receive the power diode in a form-fitting manner, in particular by means of at least one snap connection.The invention furthermore relates to a household appliance, in particular a beverage machine, with the beverage pump.The beverage pump according to the invention and / or the household appliance according to the invention should / should not be limited to the application and embodiment described above. In particular, the beverage pump according to the invention and / or the household appliance according to the invention can / can have a number deviating from a number of individual elements, components and units mentioned herein and from method steps in order to fulfil a mode of operation described herein. In addition, in the value ranges specified in this disclosure, values lying within the stated limits should also be considered as disclosed and usable as desired.DRAWINGSFurther advantages are evident from the following description of the drawings. Two exemplary embodiments of the invention are shown in the drawings. The drawings, specification and claims contain numerous features in combination. The skilled person will expediently also consider the features individually and summarize them to form meaningful further combinations.The following are shown: FIG. 1 shows a view of a household appliance according to the invention in a schematic illustration, FIG. 2 shows a beverage pump according to the invention of the domestic appliance in a schematic illustration, FIG. 3 shows the beverage pump according to the invention of the domestic appliance in a schematic exploded illustration, FIG. 4 shows the beverage pump according to the invention of the domestic appliance in a schematic side view, FIG. 5 shows a section along a longitudinal axis through the beverage pump according to the invention of the domestic appliance, and FIG. 6 shows a section along a longitudinal axis through an alternative beverage pump according to the invention of a domestic appliance.DESCRIPTION OF THE EMBODIMENTSFIG. 1 shows a household appliance 12 awhich is designed as a beverage machine. The household appliance 12 ais provided in the present exemplary embodiment for this purpose,To prepare beverages in portions and to dispense beverage portions. The household appliance 12 ais designed as a fully automatic coffee maker. The household appliance 12 aincludes storage containers for water and coffee, not shown in detail. The household appliance 12 acomprises an operating unit 44 awhich is provided for user input. The household appliance 12 aincludes a storage grid 46 aand a receptacle 48 a. The domestic appliance 12 aincludes a dispensing unit 50 afor dispensing beverage portions, in particular into a container arranged in the container receptacle 48 a. The household appliance 12 aincludes a beverage pump 10 a(cf. FIG. 2 ). The beverage pump 10a is provided for conveying a liquid, for example water, under a pressure of at least 12 bar. The beverage pump 10a is provided for delivering liquid against a ram pressure of 12 bar. It is conceivable that the beverage pump 10 ais provided for conveying a liquid under a lower pressure, such as for example of at least 8 bar, 7 bar or 4 bar. It is also conceivable for the beverage pump 10 ato be provided for conveying a liquid under a higher pressure of, for example, 15 bar. The beverage pump 10 ais provided for conveying the liquid in a main flow direction 74 a.The beverage pump 10a is formed by a swing piston pump. The beverage pump 10a has a coil carrier 14a. Furthermore, the beverage pump 10a has a coil wire which is wound onto the coil carrier 14a to form a coil 16a. The coil carrier 14a has a contact interface 54a which is provided to receive at least one end of the coil wire. The contact interface 54 aincludes a insulation displacement terminal 56 awhich is provided to electrically contact the end of the coil wire by means of an insulation displacement contact. The insulation displacement terminal 56a has a contact point designed as a plug contact for attaching an electrical feed line, in particular for contacting by means of a flat plug sleeve. Alternatively, the contact interface 54 amay include a solder contact. According to a further alternative, the contact point for attaching an electrical lead is designed as a separate component to the insulation displacement connector 56 a. According to further embodiments, the contact interface 54 acan have a contact element, in particular a screw contact or plug contact, which is alternative to the insulation displacement contact, for contacting the coil wire.The coil carrier 14a has a hollow cylindrical base body and two cover plates, wherein the base body and the cover plates are integrally connected to one another. The cover plates are arranged on opposite sides of the base body. The contact interface 54a is arranged on one of the cover plates of the coil carrier 14a.The coil carrier 14a is made at least partially of a homogeneous material. The coil carrier 14a is made entirely of a homogeneous material. The coil carrier 14 ais made at least partially, in particular completely, of glass.The coil wire includes an aluminum wire. The coil wire is formed of an insulated aluminum wire.Furthermore, the beverage pump 10 acomprises a coil housing 52 awhich is provided to partially housing the coil 16 a. The coil enclosure 52a is different from a sealing overmold of the coil 16a. The coil 16a is free of a sealing overmold. The coil housing 52 acomprises at least one wall 58 a, 60 a, in particular two walls 58 a, 60 a, which is connected to the coil carrier 14 ain a positive and / or non-positive manner, and a yoke plate 62 a.The walls 58 a, 60 aare each connected or connectable to the coil carrier 14 ain a manner such that they can be mounted and / or detached without tools. The cover plates of the coil carrier 14a have latching depressions which are provided for receiving latching pins of the walls 58a, 60a.The coil housing 52 aincludes a holder 64 afor receiving a thermal fuse 66 a. The beverage pump 10a includes the thermal fuse 66a which is received in the holder 64a. The holder 64 ais provided for arranging the thermal fuse 66 ain the vicinity of the coil. The thermal fuse 66 ais designed, for example, as a bimetallic switch, alternatively, for example, as a semiconductor switch. The holder 64 ais provided to accommodate the thermal fuse 66 aper se in an, in particular cage-like, receiving space. The holder 64 afurther includes a form-fit means, in particular a latching nose, which is provided to hold the thermal fuse 66 ain the receiving space. The bracket 64a is formed by one of the walls 58a. The holder 64a is formed integrally with the wall 58a.The yoke plate 62a is formed by a surrounding steel sheet which extends around the coil support 14a in a plane parallel to a central axis of the coil support 14a. The yoke plate 62a abuts against the cover plates of the bobbin 14a, respectively. The yoke plate 62a delimits the coil carrier 14a in four directions, wherein a fifth and sixth direction are partially delimited by the walls 58a, 60a. The yoke plate 62a has a rectangular shape.The beverage pump 10a further comprises a solenoid actuator 30a. The beverage pump 10a comprises a power piston 18a. The magnetic actuator 30 ais provided to provide a magnetic field for driving the working piston 18 a. The working piston 18a is supported in a floating manner. The beverage pump 10a comprises two spring elements 68a, 70a acting on the working piston 18a. The spring elements 68 a, 70 aare provided to act on the working piston 18 ain mutually opposite directions. One of the spring elements 68 ais designed as a pump spring. The spring element 68 a, which is designed as a pump spring, is provided for driving the working piston 18 ain a compression stroke. The spring element 68 ais designed as a helical compression spring. The working piston 18a is in a defined rest position in a magnetically unactuated state. The working piston 18 ais in a magnetically unactuated state in a defined rest position by the magnetic actuator 30 a. The working piston 18 ais held in the defined rest position by means of the spring elements 68 a, 70 aand / or moved into the defined rest position. The beverage pump 10a has a pump chamber 20a in which the working piston 18a is guided in an axially movable manner. The pump chamber 20a, when the working piston 18a is mounted, has a pre-chamber 22a, a pressure chamber 24a and an outlet chamber 26a. Furthermore, the pump chamber 20a has a piston guide 28a. The piston guide 28 aconstitutes a pump chamber wall. The working piston 18 ais guided in the pump chamber 20 aand for this purpose makes contact at least in sections with the pump chamber 20 a. The pump chamber 20a passes through the coil carrier 14a with the coil 16a. The coil 16a is provided to generate a magnetic field which partially penetrates the pumping chamber 20a. In the present exemplary embodiment, the pump chamber 20 ais at least substantially cylindrical. The pump chamber 20 acomprises a central axis 72 awhich corresponds to a cylinder axis and which is oriented at least substantially parallel to the main flow direction 74 a.The piston guide 28a is made at least partially of a homogeneous material. The piston guide 28a is made entirely of a homogeneous material. The piston guide 28a is made of a metal material. The piston guide 28a is formed by a deep-drawn part. The piston guide 28 ais formed by a deep-drawn sleeve. The piston guide 28 aon one side forms a collar for fixing the piston guide 28 abetween a bearing ring 100 aand a second pole sleeve 78 a. Furthermore, the piston guide 28 aconstitutes a step for supporting the first spring element 68 a. Furthermore, the piston guide 28 ais formed integrally with a connection element 96 a.For directing the magnetic field, the beverage pump 10 aincludes an iron circuit which partially surrounds the coil 16 a. The iron circuit comprises at least one pole sleeve 76 a, 78 ato conduct a magnetic flux generated by the magnetic actuator 30 a. The iron circuit comprises two pole sleeves 76 a, 78 aseparated from one another for conducting a magnetic flux generated by the magnetic actuator 30 a. The first pole sleeve 76 ais at least substantially in the form of a hollow cylinder. The first pole sleeve 76a has a central axis corresponding to a cylinder axis. In an assembled state, the central axis 72 aof the pump chamber 20 aand the central axis of the first pole sleeve 76 aconceeds at least substantially coincident. In an assembled state, the first pole sleeve 76 ais arranged coaxially with respect to the pump chamber 20 a. The first pole sleeve 76 ais designed as a turned part in the present exemplary embodiment. It is conceivable that the first pole sleeve 76 ais produced according to another method and is designed, for example, as a rolling part. The first pole sleeve 76 ais configured rotationally symmetrically in the present exemplary embodiment.The first pole sleeve 76a has a substantially changing magnetic conductivity along the main flow direction 74a of the liquid to be delivered. The first pole sleeve 76a has a reduced magnetic conductivity in an axial edge region 80a. The first pole sleeve 76a has a reduced effective wall material volume in the axial edge region 80a. The first pole sleeve 76a has an axial sectional profile which has a reduced wall thickness in the axial edge region 80a. The axial edge region 80 ais arranged on an axial edge of the first pole sleeve 76 a. The first pole sleeve 76a has a minimum wall thickness at the axial edge. The first pole sleeve 76 ahas a minimum wall thickness on the axial edge with respect to the edge region 80 a. In the present exemplary embodiment, the first pole sleeve 76 ahas a wall thickness of at least substantially 0.8 mm at the axial edge. It is conceivable for the first pole sleeve 76 ato have a wall thickness at the axial edge that is smaller than 0.8 mm or a disappearing wall thickness. It is conceivable for the first pole sleeve 76 ato have a wall thickness at the axial edge that is greater than 0.8 mm. In the present exemplary embodiment, the first pole sleeve 76 acomprises a conical profile in the axial edge region 80 a. The wall thickness increases in the axial edge region 80 aat a distance from the axial edge. The wall thickness increases monotonously in the axial edge region 80 aat a distance from the axial edge.The first pole sleeve 76a has a base wall thickness, with respect to which the wall thickness in the axial edge region 80a is reduced. The wall thickness is everywhere smaller than the base wall thickness in the axial edge region 80 a. The first pole sleeve 76 acomprises, outside the axial edge region 80 a, a further region in which the wall thickness corresponds continuously to the base wall thickness. The wall thickness is at least substantially constant in the further region. The further region has an axial extent which corresponds at least substantially to 80% of an axial overall extent of the first pole sleeve 76 a. The further region extends over more than two thirds of an axial overall extension of the first pole sleeve 76 a. The further region and the axial edge region 40 acomprise the complete first pole sleeve 76 a. The base wall thickness corresponds to a maximum wall thickness of the first pole sleeve 76 a. The base wall thickness in the present exemplary embodiment has a value of at least substantially 2.5 mm.The axial sectional profile of the first pole sleeve 76 ais derived from a force-displacement characteristic curve. The force-travel characteristic curve reflects the dependence of a magnetic force with respect to an axial position of the working piston 18 a. The magnetic force is provided to the magnetic actuator 20 abecause of a magnetic flux caused by the magnetic actuator 30 a.The axial section profile has at least one bevel. The bevel is arranged in the axial edge region 80 aof the axial section profile. The slope has an axial extension and a radial extension, which is derived from the force-displacement characteristic curve.The axial edge region 80 ahas an axial extent with a value of at least 2 mm. In the present exemplary embodiment, the first pole sleeve 76 acomprises an axial extent of at least substantially 18 mm. The axial edge region 80 acomprises an axial extent which is at least 20% of an axial total extent of the first pole sleeve 76 a. The axial edge region 80 ahas an axial extent with a value of at most 10 mm. The axial edge region 80 acomprises an axial extent which is at most 30% of a total extent of the first pole sleeve 76 a. In the present exemplary embodiment, the axial edge region 80 ahas an axial extent of at least substantially 4.7 mm. The axial extent of the axial edge region 80 ais at least substantially 25% of an axial total extent of the first pole sleeve 76 a.The beverage pump 10a has a second pole sleeve 78a which is arranged spaced apart from the first pole sleeve 76a. The iron circuit of the beverage pump 10a has a second pole sleeve 78a which is arranged at a distance from the first pole sleeve 76a. The second pole sleeve 78 ais at least substantially in the form of a hollow cylinder. The second pole sleeve 78 acomprises a central axis which corresponds to a cylinder axis and a central axis of the first pole sleeve 76 a. In an assembled state, the central axis 72 aof the pump chamber 20 aand the central axis of the second pole sleeve 78 aconceeds at least substantially coincident. In an assembled state, the second pole sleeve 78 ais arranged coaxially with the first pole sleeve 76 aand with the pump chamber 20 a. The second pole sleeve 78 ais designed as a rolling part in the present exemplary embodiment. It is conceivable that the second pole sleeve 78 ais produced according to another method and is designed, for example, as a turned part. The second pole sleeve 78 ais configured rotationally symmetrically in the present exemplary embodiment.The second pole sleeve 78a is spaced from the first pole sleeve 76a by a gap 82a. The second pole sleeve 78 ais provided for conducting a magnetic flux generated by a magnetic actuator 30 a. The gap 82a is formed as a magnetic insulating gap 82a. In the gap 82a, a spacer ring made of a non-magnetizable material is arranged. The first pole sleeve 76 aand the second pole sleeve 78 ainclude the magnetically insulating gap 82 abetween them in the axial direction. The magnetically insulating gap 82a interrupts the iron circuit. In an assembled state, the axial edge of the axial edge region 80 adefines the magnetically insulating gap 82 aof the iron circuit. The magnetically insulating gap 82 ais arranged spatially axially between the first pole sleeve 76 aand the second pole sleeve 78 a. The axial edge region 80 aof the first pole sleeve 76 ais arranged on a side of the first pole sleeve 76 afacing the magnetically insulating gap 82 a. The second pole sleeve 78 aconnects with one end face to the gap 82 a. The second pole sleeve 78a has a base wall thickness which corresponds to the base wall thickness of the first pole sleeve 76a. The first pole sleeve 76 aand the second pole sleeve 78 ahave the same base wall thickness. The first pole sleeve 76 aand the second pole sleeve 78 aare arranged coaxially with respect to one another. The first pole sleeve 76 aand the second pole sleeve 78 aare arranged in alignment with one another. The first pole sleeve 76 aand the second pole sleeve 78 ahave the same outer diameter. The first pole sleeve 76 ais arranged upstream of the second pole sleeve 78 awith respect to the main flow direction 74 a. The first pole sleeve 76 ais arranged on the inlet side with respect to the second pole sleeve 78 a. In an assembled state, an axial extent of an arrangement consisting of the first pole sleeve 76 a, the magnetically insulating gap 82 aand the second pole sleeve 78 ais greater than an axial extent of the coil 16 a.The first pole sleeve 76 aand the second pole sleeve 78 aeach surround the pump chamber 20 a. The first pole sleeve 76 aand the second pole sleeve 78 aare arranged radially between the coil 16 aand the pump chamber 20 a. The second pole sleeve 78a has a chamfer on an edge facing the magnetically insulating gap 82a. The chamfer is arranged on an outer circumference of the further pole sleeve 78 a. The chamfer has an angle of at least substantially 45 degrees. It is conceivable for the chamfer to have an angle deviating from 45 degrees, for example a flatter angle or a steeper angle, with respect to the outer circumference. The chamfer has a width of at least substantially 1.5 mm. It is conceivable for the chamfer to have a greater width or a smaller width. It is conceivable for the second pole sleeve 78 ato be formed without bevels.The working piston 18 aof the beverage pump 10 aincludes an armature element 84 awhich is made entirely of a magnetizable material.To achieve a pumping effect, the coil 16 ais energized with a pulse-shaped voltage, whereby a continuously changing magnetic field is established in the region of the pump chamber 20 a. The magnetic field, which changes in a pulse-like manner and is conducted through the pole sleeves 76 a, 78 a, has the effect that the working piston 18 ais initially deflected from its rest position counter to the force of the spring element 68 a, which is designed as a pump spring, with increasing strength of the magnetic field. A magnetic force acting on the working piston 18 adepends on a field density at the location of the armature element 84 a, which in turn is determined in particular by the shape of the pole sleeves 76 a, 78 a. As soon as current through the coil 16 ais reduced and thus the strength of the magnetic field falls again, the working piston 18 ais moved in the direction of the rest position by the force of the spring element 68 a. In this case, a diode unit, not shown in detail, is preferably connected upstream of the coil 16 a, as a result of which the coil 16 ais energized only with a half wave of an alternating voltage. In the illustrated embodiment, the coil 16a is provided for an AC voltage of 230 V at 50 Hz.At least depending on the shape of the pole sleeves 76 a, 78 a, a defined characteristic curve of the beverage pump 10 acan be achieved in particular.The power piston 18a includes a piston valve 86a fluidly disposed between the pre-chamber 22a and the pressure chamber 24a. The piston valve 86 ais arranged centrally in the beverage pump 10 aand centrally in the working piston 18 awith respect to a longitudinal axis of the beverage pump 10 a. The piston valve 86 ais formed in the form of a check valve which has a direction of passage from the pre-chamber 22 ainto the pressure chamber 24 a. The spool valve 86a includes a valve seat 88a, a closure member 90a and a closing spring 92a. The closing spring 92 ais provided to pull the closing part 90 aon the valve seat 88 a. In a filling stroke, in which the working piston 18 ais moved by the magnetic field counter to the force of the spring element 68 a, which is designed as a pump spring, fluid flows from the prechamber 22 athrough the piston valve 86 ainto the pressure chamber 24 a. In a subsequent compression stroke, in which the working piston 18 ais moved by the force of the spring element 68 a, the fluid is forced out of the pressure chamber 24 a. The maximum pressure which acts on the fluid in this case depends in particular on the force of the spring element 68 a. A path by which the working piston 18 ais moved in this case depends on a configuration of the beverage pump 10 a, in particular on the shape of the pole sleeves 76 a, 78 a.The beverage pump 10a has two connection elements 94a, 96a. A first of the connection elements 94 ais designed as an inlet element and is provided for connection to a water feed, for example to a water storage container. The first connection element 94a has a connecting piece 98a for connection to a hose. It is conceivable for the first connection element 94 ato have a connection coupling. A further one of the connection elements 96 ais designed as an outlet element and has a connection coupling. It is conceivable for the further connection element 96 ato have a connecting piece.The further one of the spring elements 70 ais designed as a damping element. The further of the spring elements 70 ais designed as a helical spring in the present exemplary embodiment. The working piston 18 ais supported in a floating manner between the two spring elements 68 a, 70 a. The working piston 18 ais in contact with both spring elements 68 a, 70 ain an at least substantially uninterrupted manner. It is conceivable that the further one of the spring elements 70 ais designed as another elastic element, for example as a bellows element and / or as a porous element. The beverage pump 10 aincludes a bearing ring 100 afor a sealing element 102 a. The sealing element 102 ais provided for sealing the prechamber 22 arelative to the pressure chamber 24 a. In an assembled state, the working piston 18 atransfiltrates the bearing ring 100 a. The sealing element 102 atogether with the working piston 18 aform a sliding seal.Beverage pump 10a includes an outlet valve 32a fluidly disposed between pressure chamber 24a and outlet chamber 26a. The outlet chamber 26 ais formed by the further connection element 96 a. The outlet valve 32 ais arranged centrally in the beverage pump 10 aand centrally in the outlet chamber 26 a, with respect to the longitudinal axis of the beverage pump 10 a. The outlet chamber 26a is fluidly disposed between the pressure chamber 24a and an outlet port. The discharge valve 32 ais formed as a check valve having a passing direction from the pressure chamber 24 ato the discharge chamber 26 a. The pressure chamber member has a circular opening forming a valve seat for the discharge valve 32a. The outlet valve 32a includes a compression chamber unit 34a having a compression chamber housing 36a and a valve element 38a.The valve element 38a is made at least partially of glass. The valve element 38a is made entirely of glass. The valve element 38a is formed by a glass ball.The valve element 38a is axially movably supported in the compression chamber unit 34a. The compression chamber unit 34 aincludes the compression chamber housing 36 a, a first compression chamber inner part 104 athat partially delimits the pressure chamber 24 a, and a second compression chamber inner part 106 athat partially delimits the outlet chamber 26 a. The piston valve 86 aof the working piston 18 aprotrudes into the first compression chamber inner part 104 ain operation. Preferably, the valve element 38 ais guided in the first compression chamber inner part 104 a. The valve element 38a is fully disposed in the first compression chamber inner portion 104a. The first compression chamber inner part 104 ais hollow-cylindrically shaped and has an inwardly projecting collar as a sealing seat for the valve element 38 aand, on an end facing away from the second compression chamber inner part 106 a, an outwardly directed collar which forms a circumferential groove on the inside. The groove serves in particular for receiving the sealing element 102 a. The sealing element 102 ais provided for sealing the prechamber 22 arelative to the pressure chamber 24 a. The second compression chamber inner part 106 ais pot-shaped.The first compression chamber inner member 104a and the second compression chamber inner member 106a form an insert in the compression chamber housing 36a. The first compression chamber inner member 104 aand the second compression chamber inner member 106 aare detachably inserted into the compression chamber housing 36 a. The first compression chamber inner part 104 aand the second compression chamber inner part 106 aare positively held in the compression chamber housing 36 a.The compression chamber housing 36a is made at least partially of a homogeneous material. The compression chamber housing 36a is made entirely of a homogeneous material. The compression chamber housing 36a is made of a metal material. The compression chamber housing 36a is formed by a deep-drawn part. The compression chamber housing 36 aconstitutes a collar on one side for fixing the compression chamber housing 36 a. For this purpose, the beverage pump 10a has a mounting ring 108a, by means of which the collar of the compression chamber housing 36a can be clamped between the mounting ring 108a and the second pole sleeve 78a. The mounting ring 108 ais screwed to the yoke plate 62 a, in particular. Furthermore, the compression chamber housing 36 ais formed integrally with a connection element 96 a.The piston guide 28 aand / or the compression chamber housing 36 aare free of glass fibers. The piston guide 28a and the compression chamber housing 36a are free of glass fibers. The piston guide 28 aand the compression chamber housing 36 aare free of a composite material.FIG. 6 shows a further exemplary embodiment of the invention. The following descriptions are limited substantially to the differences between the exemplary embodiments, wherein reference can be made to the description of the exemplary embodiment of FIGS. 1 to 5 with respect to components, features and functions which remain the same. To distinguish between the exemplary embodiments, the letter a in the reference numerals of the exemplary embodiment in FIGS. 1 to 5 is replaced by the letter b in the reference numerals of the exemplary embodiment in FIG. 6. With regard to identically designated components, in particular with regard to components with the same reference numerals, reference can also be made in principle to the drawings and / or the description of the exemplary embodiment of FIGS. 1 to 5.FIG. 6 shows an alternative beverage pump 10 b. The beverage pump 10 bis formed by a swing piston pump. The beverage pump 10 bhas a coil carrier 14 b. Furthermore, the beverage pump 10 bhas a coil wire which is wound onto the coil carrier 14 bto form a coil 16 b. Furthermore, the beverage pump 10 bhas a coil housing 52 b, which is provided to partially housing the coil 16 b. The beverage pump 10 bfurther comprises a magnetic actuator 30 b. The beverage pump 10b comprises a power piston 18b.The beverage pump 10 bhas a pump chamber 20 b, in which the working piston 18 bis guided in an axially movable manner. The pump chamber 20b, when the working piston 18b is mounted, has a pre-chamber 22b, a pressure chamber 24b and an outlet chamber 26b. Furthermore, the pump chamber 20 bhas a piston guide 28 b. The piston guide 28 bconstitutes a pump chamber wall. The working piston 18 bis guided in the pump chamber 20 band contacts the pump chamber 20 bto this end at least in sections. The pump chamber 20 btransmits the coil carrier 14 bwith the coil 16 b.The piston guide 28 bis made at least partially of a homogeneous material. The piston guide 28 bis made entirely of a homogeneous material. The piston guide 28 bhas a base body 40 bmade of a plastic and a reinforcing sleeve 42 bmade of a metal material. The base body 40 band the reinforcing sleeve 42 bare connected to one another in a form-fit and / or force-fit manner and free from a material bond. The reinforcing sleeve 42 bis formed by an inner metal tube adjoining the base body 40 b. The metal tube has a material thickness that is less than a material thickness of the base body 40 b. The base body 40 bhas a hollow cylindrical basic shape with a connection element 94 bformed integrally on. A material thickness of the reinforcing sleeve 42 bis less than 3 mm, preferably less than 2 mm and particularly preferably less than 1 mm. The pole sleeves 76 b, 78 bare arranged on the base body 40 b. However, it would also be conceivable for the pole sleeves 76 b, 78 bto be arranged between the base body 40 band the reinforcing sleeve 42 bor to be partially accommodated in the base body 40 b. The base body 40b forms a collar on one side for fixing the piston guide 28b between a bearing ring 100b and the second pole sleeve 78b. Furthermore, the base body forms a stop for supporting a first spring element 68 b.Beverage pump 10b includes an outlet valve 32b fluidly disposed between pressure chamber 24b and outlet chamber 26b. The outlet chamber 26 bis formed by the further connection element 96 b. The outlet valve 32 bis arranged centrally in the beverage pump 10 band centrally in the outlet chamber 26 b, with respect to the longitudinal axis of the beverage pump 10 b. The outlet chamber 26 bis disposed fluidly between the pressure chamber 24 band an outlet port. The discharge valve 32 bis formed as a check valve having a passing direction from the pressure chamber 24 bto the discharge chamber 26 b. The pressure chamber member has a circular opening forming a valve seat for the discharge valve 32b. The outlet valve 32b includes a compression chamber unit 34b having a compression chamber housing 36b and a valve element 38b.The valve element 38 bis axially movably supported in the compression chamber unit 34 b. The compression chamber unit 34 bincludes the compression chamber housing 36 band a compression chamber inner part 104 bwhich partly delimits the pressure chamber 24 b. A piston valve 86 bof the working piston 18 bprotrudes into the compression chamber inner part 104 bin operation. Preferably, the valve element 38 bis guided in the compression chamber inner part 104 b. The valve element 38b is fully disposed in the compression chamber inner portion 104b. The first compression chamber inner part 104 bis hollow-cylindrically shaped and has an inwardly projecting collar as a sealing seat for the valve element 38 band an outwardly directed collar which forms a circumferential groove on the inside. The groove serves in particular for receiving a sealing element 102 b. The sealing element 102 bis provided for sealing the prechamber 22 bfrom the pressure chamber 24 b.The compression chamber inner portion 104b forms an insert in the compression chamber housing 36b. The compression chamber inner member 104b is detachably disposed in the compression chamber housing 36b. The first compression chamber inner part 104 bis positively held in the compression chamber housing 36 b.The compression chamber housing 36 bis made at least partially of a homogeneous material. The compression chamber housing 36 bis made entirely of a homogeneous material. The compression chamber housing 36b is made entirely of a plastic material. The compression chamber housing 36 bis made of a homogeneous plastic. The compression chamber housing 36 bhas an increased wall thickness. The compression chamber housing 36 bhas an average wall thickness of at least 1.5 mm, preferably at least 2 mm and particularly preferably at least 2.5 mm. The compression chamber inner part 36 bis in particular likewise made of a homogeneous plastic. The compression chamber housing 36b forms a collar on one side for fixing the compression chamber housing 36b. For this purpose, the beverage pump 10 bhas a mounting ring 108 b, by means of which the collar of the compression chamber housing 36 bcan be clamped between the mounting ring 108 band the second pole sleeve 78 b. The mounting ring 108 bis screwed in particular to a yoke plate 62 b. Furthermore, the compression chamber housing 36 bis formed integrally with a connection element 96 b.The piston guide 28 band / or the compression chamber housing 36 bare free of glass fibers. The piston guide 28 band the compression chamber housing 36 bare free of glass fibers. The piston guide 28 band the compression chamber housing 36 bare free of a composite material.List of reference characters10 Beverage pump 12 Household appliance 14 Coil carrier 16 Coil 18 Working piston 20 Pump chamber 22 Pre-chamber 24 Pressure chamber 26 Outlet chamber 28 Piston guide 30 Magnetic actuator 32 Outlet valve 34 Compression chamber unit 36 Compression chamber housing 38 Valve element 40 Base body 42 Reinforcing sleeve 44 Operating unit 46 Shelf 48 Vessel receptacle 50 Output unit 52 Coil housing 54 Contact interface 56 Cutting clamp 58 Wall 60 Wall 62 Yoke plate 64 Holder 66 Thermal fuse 68 Spring element 70 Spring element 72 Central axis 74 Main flow direction 76 Pole sleeve 78 Pole sleeve 80 Edge region 82 Gap 84 Armature element 86 Piston valve 88 Valve seat 90 Closure part 92 Closing spring 94 Connection element 96 Connection element 98 Connection piece 100 Bearing ring 102 Sealing element 104 Compression chamber inner part 106 Compression chamber inner part 108 Mounting ring

Claims

Beverage pump, in particular a swing piston pump, for a domestic appliance (12a), in particular for a beverage machine, for conveying a liquid, having at least one coil carrier (14a; 14b), at least one coil wire which is wound onto the coil carrier (14a; 14b) to form a coil (16a; 16b), having a working piston (18a; 18b), having a pump chamber (20a; 20b) in which the working piston (18a; 18b) is guided in an axially movable manner, which, when the working piston (18a; 18b) is mounted, has a pre-chamber (22a; 22b), a pressure chamber (24a; 24b) and an outlet chamber (26a; 26b) and which has a piston guide (28a; 28b), having a magnetic actuator (30a; 30b) which is provided for providing a magnetic field for driving the working piston (18a; 18b) and having an outlet valve (32a; 32b) which is arranged fluidically between the pressure chamber (24a; 24b) and the outlet chamber (26a; 26b) and which has at least one compression chamber unit (34a; 34b) having a compression chamber housing (36a; 36b) and at least one valve element (38a; 38b), characterized in that the piston guide (28a; 28b) and / or the compression chamber housing (36a; 36b) is free of glass fibres.Beverage pump according to claim 1, characterised in that the piston guide (28a; 28b) consists at least partially, in particular completely, of a homogeneous material.Beverage pump according to claim 1 or 2, characterised in that the piston guide (28a; 28b) is at least partially made of a metal material.Beverage pump according to one of the preceding claims, characterised in that the piston guide (28a) is formed by a deep-drawn part.Beverage pump according to one of the preceding claims, characterised in that the piston guide (28b) has a base body (40b) made of a plastic and at least one reinforcing sleeve (42b) made of a metal material.Beverage pump according to claim 5, characterised in that the reinforcing sleeve (42b) is formed by an inner metal tube adjoining the base body (40b).Beverage pump according to one of the preceding claims, characterized in that the compression chamber housing (36a; 36b) is made partly, in particular completely, of a homogeneous material.Beverage pump according to any of the preceding claims, characterised in that the compression chamber housing (36a) is made at least partially from a metal material.Beverage pump according to one of the preceding claims, characterized in that the compression chamber housing (36a) is formed by a deep-drawn part.Beverage pump according to one of the preceding claims, characterized in that the compression chamber housing (36b) is made entirely of a plastic material.Beverage pump according to one of the preceding claims, characterized in that the valve element (38a; 38b) is made partly, in particular completely, of glass.Beverage pump according to claim 11, characterised in that the valve element (38a; 38b) is formed by a glass ball.Beverage pump according to one of the preceding claims, characterized in that the coil carrier (14a; 14b) consists at least partially, in particular completely, of a homogeneous materialBeverage pump according to claim 13, characterised in that the coil carrier (14a; 14b) is made partly, in particular completely, of glass.Domestic appliance, in particular beverage machine, with a beverage pump (10a; 10b) according to one of the preceding claims.

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