Actuator module

Abstract

The invention relates to an actuator module (1) having a hermetically sealed module housing (3) which extends longitudinally in an axial direction (RAX), having at least one piezo actuator (2) arranged in the module housing (3) and having electric connections (6a, 6b) at least for the piezo actuator (2), said connections (6a, 6b) being guided through a module housing wall (3w), wherein a module housing interior (3i) between the piezo actuator (2) and the module housing wall (3w) comprises a potting compound (4) which electrically insulates the module housing wall (3w) from the piezo actuator (2) and is designed in a head-conducting manner, in particular with a heat-conducting auxiliary, wherein the module housing wall (3w) of the module housing (3) has a corrugated bellows (10, 20, 30, 40) with a corrugation contour (10, 20, 30, 40), wherein at least one portion (14, 34l, 34r, 44l, 44r) of the corrugation contour (10, 20, 30, 40) is formed helically in the axial direction (RAX). The invention also relates to a metering system (50) having such an actuator module (1).

Description

[0001] Actuator module

[0002] The invention relates to an actuator module with a hermetically sealed module housing extending longitudinally in an axial direction with at least one piezo actuator arranged in the module housing and with electrical connections at least for the piezo actuator and a dosing system with such an actuator module.

[0003] Piezoceramic multilayer actuators, or piezo actuators for short, consist of a multitude of stacked thin layers of a piezoelectric material, e.g., lead zirconate titanate. In such multilayer piezo actuators (also called "multilayer elements," "piezo stacks," or "piezo stacks"), cascading occurs by assembling several thin piezo elements with internal electrodes in between. The internal electrodes are alternately applied to a surface of the piezo actuator, with two external electrodes connecting the respective internal electrodes. The internal electrodes are electrically connected in parallel and combined into two groups, which form the terminals of the piezo actuator. When an electrical voltage is applied to the terminals, this voltage is transferred in parallel to the internal electrodes, thereby creating an electric field in the layers of the piezoelectric material.The sum of the mechanical deformations of the individual layers of the piezoelectric material results in the usable strain and / or force of the piezo actuator.

[0004] Piezo actuators are used in a variety of technical fields, e.g., in actuators and positioning drives or in dosing systems for the targeted dosing of liquid to viscous dosing materials, particularly in so-called jet valves. Particular advantages of piezo actuators include their high rigidity and pressure resistance, their high position resolution, their fast response, their ability to achieve high accelerations, and their essentially wear-free operation.

[0005] Despite these advantages, heat dissipation from piezo actuators has often proven inadequate in the past. Particularly with piezo actuators that are enclosed for protection against external influences, e.g., a sealed housing with a piezo actuator inside, sufficient heat dissipation from the piezo actuator during operation may not be guaranteed. The temperature of a piezo actuator can affect its geometry in any control state, including its longitudinal extension in an (unswitched) idle state.

[0006] As a result of a thermally induced change in length, particularly due to insufficient heat dissipation from the piezo actuator during operation, the longitudinal expansion of the piezo actuator caused by the wiring of the piezo actuator and / or a generated force and / or a position of the piezo actuator within a machine may deviate from a specific target value. However, since particularly high precision in the operation of the piezo actuator is required in many applications, temperature-induced change in length of a piezo actuator should be avoided wherever possible.

[0007] Consequently, known piezo actuators, especially piezo actuators arranged in a tightly sealed enclosure, for example, in a metal module housing, possibly using a specific medium, e.g., a water-absorbing medium in the module housing, can only be used to a limited extent in many technical fields. Particularly for the jet valves mentioned above, which currently typically operate at high clock frequencies of more than 1 kHz, generating correspondingly high heat loss in the piezo actuator, an actuator module is desirable that enables sufficient heat dissipation from the surface of the piezo actuator while simultaneously effectively shielding the piezo actuator from harmful environmental conditions for reliable operation.

[0008] It is an object of the present invention to provide an actuator module with a hermetically sealed housing and a dosing system with such an actuator module, with which the disadvantages described above can be avoided or at least reduced.

[0009] This object is achieved by an actuator module according to patent claim 1 and a dosing system according to patent claim 10.

[0010] An actuator module according to the invention has a hermetically sealed, in particular internally sealed, module housing. The module housing extends longitudinally, in particular in the longitudinal direction, in an axial direction. In other words, the direction of a longest extension of the module housing is referred to as the axial direction. The axial direction is preferably parallel to the longitudinal extension of the piezo actuator arranged in the module housing. The module housing is preferably longer in the axial direction than in a direction orthogonal to the axial direction. The module housing can preferably be designed or shaped essentially as a "hollow cylinder," i.e., have a round cross-section.

[0011] At least one piezo actuator is arranged in the interior of the module housing, which is preferably completely hermetically sealed. It can, for example, be centrally aligned therein. However, it is also conceivable in principle for two or more piezo actuators to be hermetically sealed within the same module housing. For example, two separately controllable piezo actuators could be arranged substantially parallel to one another in the same module housing. The invention is described below, without limitation and unless otherwise stated, using a module housing with only one piezo actuator.

[0012] The piezo actuator can, in particular, be a piezoceramic multilayer actuator comprising a plurality of layers in the longitudinal direction. The actuator module has at least two electrical connections, at least for the piezo actuator. The electrical connections are routed through a module housing wall, in particular in a hermetically sealed and electrically insulated manner.

[0013] In the context of the invention, the term “hermetically” sealed is understood to mean that the module housing is designed in such a way that no substances can pass through the module housing or no substances can penetrate through the sealed module housing. The module housing is “hermetically” sealed in such a way that no solids and / or liquids and / or gases can enter the module housing from the outside when the actuator module is in operation. In this respect, the hermetically sealed module housing can also be referred to as an impermeable module housing, which is designed so impermeably that nothing can penetrate or escape. The module housing preferably forms an “absolutely tight” closure or enclosure of the piezo actuator from the environment of the module housing, i.e. the piezo actuator is surrounded or encased on all sides by the module housing.An "absolutely sealed" module housing is understood to mean that, in particular, an exchange of air and / or water molecules via the module housing is prevented. Accordingly, the module housing can be "absolutely sealed" for a certain operating period, at least (relatively) with respect to air and / or water molecules, in particular to prevent long-term diffusion of water molecules through the materials of the module housing during operation. The tightness of the module housing can be tested, for example, using a helium leak test. The module housing can, in particular, be a deep-drawn module housing, as described later.

[0014] This distinguishes the module housing from known enclosures such as metal sleeves, which are simply pushed onto a piezo actuator, with individual piezo actuator sections, such as an actuator end, protruding from the sleeve. Such sleeves are therefore not a "hermetically" sealed module housing within the meaning of the invention.

[0015] Furthermore, a potting compound is arranged in a housing interior within the module housing between the piezo actuator, in particular a surface of the piezo actuator, and the module housing wall, in particular an inner side, which potting compound electrically insulates the module housing wall from the piezo actuator, in particular during operation of the piezo actuator. The insulation resistance of the basic components of the potting compound, in particular a base compound, e.g., a silicone gel, is preferably at least 1 10 12 Q cm, preferably at least 1 ■ 10 15 Q cm, in particular at least 1 ■ 10 16 Q cm or more.

[0016] At this point it should be explicitly mentioned again that if there is more than one piezo actuator in the module housing interior, the potting compound can be applied both between the respective piezo actuators and around the piezo actuators between the module housing wall and the respective piezo actuators.

[0017] According to the invention, the potting compound is designed to be thermally conductive. The potting compound is preferably designed to be thermally conductive such that the heat generated by the piezo actuator during operation can be dissipated from the inside, in particular from a piezo actuator surface, through the potting compound to the outside of the module housing wall. The heat dissipated by the piezo actuator can, in particular, be waste heat generated during operation of the piezo actuator. The potting compound can preferably comprise at least one thermally conductive auxiliary material to make the potting compound thermally conductive.

[0018] The thermal conductivity of the potting compound (in the module housing interior) can be at least 0.5 W / (m K), preferably at least approximately 1.0 W / (m K), more preferably at least approximately 1.5 W / (m K), more preferably at least approximately 2.0 W / (m K), particularly preferably at least approximately 2.25 W / (m K), in particular at least approximately 2.45 W / (m K). Furthermore, the module housing wall of the module housing has a corrugated bellows with a corrugated contour. It can be provided that only a certain part of the module housing wall has a corrugated bellows, in which case at least a region of the housing wall is designed without a corrugated bellows. For example, the end faces of the module housing which delimit the module housing in the axial direction can be designed without a corrugated bellows. A corrugated contour is understood here to mean a wave-shaped structure of the module housing wall and / or of a surface, in particular an outer surface, of the module housing wall, which has alternating depressions and / or depressions in the axial direction of the module housing.Has depressions and elevations. Preferably, the respective depressions can be concave and the respective elevations convex. The bellows can preferably be formed in the axial direction between a first (e.g., upper) end face or head face and a second (e.g., closed, lower) end face or end face of the module housing wall, in particular opposite the first end face, as an integral lateral surface of the module housing wall.

[0019] The module housing wall with the bellows is designed to house a piezo actuator, as will be described in more detail below in the context of the explanation of a dosing system according to the invention with at least one such actuator module, which is or can be installed, preferably with a precise fit, in a cylindrical recess in a housing of a dosing system.

[0020] According to the invention, at least one section of the corrugated contour of the bellows is helical or spiral in the axial direction of the module housing or with respect to the axial direction. This means that the section has at least one spiral elevation, which, together with an adjacent spiral depression, in particular in the form of a groove, winds along the (outer) module housing wall of the module housing, partly in the circumferential direction (of the module housing) and partly in the axial direction (of the module housing).

[0021] Preferably, a helically shaped section can have at least one, preferably concave, groove-like depression, which is bordered on both sides by an adjacent, preferably convex, elevation, wherein the groove-like depression forms a curve that winds around the outer circumference of the module housing with a, preferably constant, gradient. Such a groove-like depression can preferably form a helix in the (outward-facing) module housing wall. Accordingly, the helically shaped section can have at least one helix or helical structure, in particular in the form of a groove-like depression in the (outward-facing) module housing wall. Preferably, at least the region of the module housing wall that comprises the helically shaped section is cylindrical. Preferably, at least one helically shaped section can be formed in a cylindrical jacket surface of the module housing.A groove-like depression is synonymously referred to as a “groove”.

[0022] A helical portion may include at least one groove extending over at least a portion of an outer periphery of the module housing.

[0023] Preferably, a helically shaped section can have at least one continuous groove that completely surrounds the module housing at least once, preferably twice or more, on the outside. The individual turns of the groove-like recess are preferably separated from one another by a respective elevation, e.g., a convex one.

[0024] Preferably, a helically shaped section can be formed such that a starting region of a groove and an end region of the same groove are offset from one another with respect to a longitudinal direction of the actuator module and / or the module housing.

[0025] This means that, unlike a bellows known from practice, with elevations or depressions winding azimuthally at a constant height or location in the axial direction (without gradient or progression in relation to the axial direction), the convex elevations and the intervening concave depressions of the shaft contour alternating in the axial direction not only run in a circumferential direction or azimuthal direction perpendicular to the axial direction, but simultaneously in a circumferential direction and also in an axial direction of the module housing, in particular the module housing wall. Such a bellows with azimuthally running grooves that alternate in the axial direction with azimuthal elevations, ieThe uniform cooling of a cylinder head whose cylinder surface has a meandering surface profile is a challenge and fraught with problems: In order to achieve uniform cooling over the entire axial length, i.e. all grooves and elevations, each individual groove or meander depression must be supplied with a targeted supply and removal of the coolant. In order to ensure that all meander depressions or grooves are evenly flowed around and that the rest are not left without cooling in the worst case scenario, so-called throttle bores are additionally introduced. However, such throttle bores have the disadvantage that they increase the flow resistance, so that in some cases more pressure must be used than without the throttle bores. In addition, it is mechanically complex to achieve the previously required "individual meander cooling" because very small (nozzle) bores are required as throttles and a corresponding supply of e.g.The large-volume supply and discharge of the cooling medium must be introduced via a very long axial bore through the housing along the bellows. This is also a cost factor, as very long bores are particularly difficult to mass-produce. Combined with the numerous small transverse bores (for nozzles), this also poses a certain manufacturing risk (e.g., broken drill bits, etc.).

[0026] The alternating elevations and depressions of the module housing wall in question preferably extend with a constant gradient in the azimuthal and axial directions, thus in a helical shape, around the module housing wall, in particular around the outer surface of the module housing. The flow resistance is thus considerably lower, since the cooling medium flow spreads or flows constantly and evenly along the helix, so that a high flow velocity can be achieved with less pressure, which is important for effective cooling. In addition, no throttle holes are required. In the simplest case (with a bellows with a continuous helix (explained below) extending from one end region in the axial direction to the other opposite end region), one inlet and one outlet are sufficient, at which the cooling medium is admitted at one end (e.g. at one end of the helix) and discharged at the other (e.g.at the opposite end of the helix) can be released again after passing through the entire helix, so that the entire helix can be cooled evenly and very effectively.

[0027] Advantageously, the actuator module according to the invention can improve the reliability of a piezo actuator, since the piezo actuator is effectively protected against harmful environmental influences, in particular against (atmospheric) humidity, during operation by the hermetically sealed module housing. Furthermore, the combination with the potting compound in the module housing interior between the piezo actuator and the module housing wall not only electrically insulates the module housing wall from the piezo actuator, but also efficiently conducts heat from the piezo actuator outwards into or onto the module housing wall. From there, it can be dissipated particularly efficiently by means of the corrugated contour of the corrugated bellows of the module housing wall, which is helical in at least one section, through the flow of a cooling medium - as mentioned further below. The piezo actuator can thus be reliably protected from overheating.This, in turn, can have a beneficial effect on the service life of the piezo actuator itself, so that it or the actuator module needs to be replaced less frequently. On the other hand, the actuator module can achieve particularly high dosing precision in dosing systems, as thermally induced length changes of at least one piezo actuator are largely prevented. This also improves the efficiency of a dosing system, as the piezo actuator is protected from overheating even during continuous operation, thus avoiding interruptions in dosing due to a critical piezo actuator temperature.

[0028] Furthermore, the actuator module according to the invention is also advantageously suitable for applications in which particularly high clock frequencies of a piezo actuator are required, since the potting compound in the module housing interior between the piezo actuator and the module housing wall enables particularly efficient dissipation of waste heat from a piezo actuator surface to the module housing wall, and particularly effective heat dissipation to the environment is possible via the helical section of the wave contour of the module housing wall. The actuator module can therefore advantageously be used in jet valves with a very high clock frequency of, for example, up to 2 kHz, which corresponds to at least twice the clock frequency compared to conventional jet valves and which is not easily possible with known actuator modules. Furthermore, the actuator module could also be profitably used in jet valves that operate at clock frequencies of 3 kHz or 4 kHz.

[0029] A dosing system according to the invention for a dosing substance comprises a nozzle for dispensing the dosing substance, a feed channel for the dosing substance, an ejection element, and at least one actuator module as described above coupled to the ejection element. For dispensing the dosing substance, the actuator module can interact with the ejection element and / or the nozzle during operation.

[0030] The dosing system also includes a system housing, hereinafter referred to as “housing” for short, with at least one cylindrical recess in a housing section otherwise made, for example, from solid material, into which recess the actuator module is inserted, preferably with a precise fit, during dosing operation. The actuator module can preferably be braced at the head end via a tensioning spring in the housing and at the front end against a transmission lever, which transmission lever can in turn be braced against an ejection element, among other things. “Precise fit” is to be understood in such a way that the internal dimensions of the recess and / or the external dimensions of the actuator module are selected or dimensioned exactly so that there is as little free space as possible between the two components. This means:, preferably the actuator module is inserted into the dosing system with a precise fit, apart from a small gap, so that an expansion movement of the actuator module in the recess can still take place during operation without the bellows becoming jammed in the recess of the housing. In particular, the actuator module and / or the cylindrical recess can be designed and / or coordinated with one another in such a way that a cooling medium which is supplied to a (respective) groove is largely guided through this groove by an interaction of the elevations delimiting the groove and the housing wall of the recess, ie at least a large part of the supplied volume passes through the groove and only a small part, preferably less than 10%, of the cooling medium overflows or jumps over the elevations delimiting the groove, essentially perpendicular to the direction of extension of the groove.

[0031] In order to completely prevent overflow or skipping due to a small distance between the elevations of the bellows and the recess in the dosing system housing, the actuator module can preferably be provided with a tubular cover for dosing operation, which is particularly preferably pulled onto or around the actuator module to fit exactly or with which the actuator module is surrounded. Such a cover can comprise at least two openings, e.g. an inlet and an outlet opening, in its material surface, i.e. be provided with at least two holes. Otherwise, the cover can envelop the actuator module on both sides during dosing operation in a dosing system. Cooling medium can be admitted through the openings into the groove of the actuator module covered by the cover, i.e. bordered radially outwards, and can be discharged again at the end of the groove.

[0032] The cover is, for example, an elastic, i.e. expandable, and temperature-resistant rubber cover or the like, which can elastically yield to a certain expansion movement of the actuator module.

[0033] Preferably, the cover can form a tight, hermetic seal on all sides of the actuator module's bellows grooves radially outward against the surrounding housing. Among other things, this eliminates the need for the housing recess itself to provide the necessary sealing by being designed so tightly or tightly that the actuator module just barely fits. Rather, the recess in the dosing system's housing can also be designed with some clearance relative to the actuator module.

[0034] Particularly preferably, supply hoses, i.e., an inlet hose and a discharge hose, can be connected to the inlet and outlet openings of the overshoe. For example, they can be vulcanized directly during the manufacture and / or attachment of the overshoe. With longer supply hoses, which, for example, extend from the recess in the housing, it is possible to dispense with holes for the supply and discharge of the cooling medium, which would otherwise open into the recess in the housing.

[0035] If a dispensing system has multiple cylindrical recesses, it is preferable to use one actuator module per recess. Multiple actuator modules are useful, for example, if dispensing is required at a particularly high cycle frequency.

[0036] The housing of the dosing system for cooling, in particular of the actuator module, has at least one inlet opening in the recess for introducing a cooling medium into at least one groove on the outside of the bellows. Furthermore, the housing of the dosing system has at least one outlet opening from the recess for discharging the cooling medium from at least one groove. After the cooling medium has been introduced into a groove at a first point in relation to the axial direction or in relation to a position along the shaft contour, the cooling medium is discharged again or discharged at a different, later point or at a different position along the shaft contour, preferably from the same groove. With a corresponding design of the bellows, the discharge could also take place from a different groove, as will be explained further below. The inlet or outlet opening is the actual opening, i.e. inlet or outlet.Exit point at which the cooling medium is fed into or out of the groove on the outside of the bellows.

[0037] Liquid and / or gaseous media are suitable as cooling media, with cooling media with a high heat capacity being preferred. The cooling medium can therefore be a gas such as helium, for example. The cooling medium can preferably be air. Gas, in particular air, has the advantage that the components around which it flows are not contaminated and, even in the event of a leak, no cleaning etc. is necessary. Compressed and (actively) cooled air can particularly preferably be used as the cooling medium, as this can be provided with relatively little effort and can be blown into a groove in the bellows through an inlet opening. For example, at least one vortex tube can be implemented as a cold source in order to cool the cooling medium to a specific (target) temperature. This means that the cooling medium for the dosing system can be used even under unfavorable ambient conditions, such as, for example,particularly high ambient temperatures, operate with a maximum dosing frequency, while at the same time ensuring high dosing precision.

[0038] Alternatively or additionally, the cooling medium can also be a liquid such as water, alcohol or oil.

[0039] During operation, the bellows, as mentioned, is inserted into the preferably precisely fitting, cylindrical recess. The recess can, for example, be a hole in the housing of the dosing system. By introducing the cooling medium into a space between the bellows and the recess, i.e. in the case of a precisely fitting recess then (if possible) completely into a spiral or helical recess or groove in the outer contour of the bellows that winds along the bellows, the cooling medium can be transported or guided on the outside of the bellows from an inlet point, e.g. at one end of the bellows, to another outlet point, e.g. at the other end of the bellows. The cooling medium can advantageously be guided through the helical or spiral groove over a defined distance in the circumferential direction and in the longitudinal direction of the actuator module.Through the interaction of at least one groove in the module housing with an inlet opening and an associated outlet opening, a directed cooling medium flow can be generated, so that a specific (partial) section of the actuator module is continuously, in particular evenly, flowed around by cooling medium. Advantageously, even areas of the actuator module that are spaced from an inlet opening can be reliably supplied with cooling medium during operation by means of a flow guide through a groove. This advantageously makes it possible to achieve constant and even cooling of the module housing wall with the helical section. In contrast, in known encapsulated piezo actuators, exposure to compressed air, for example, can lead to different areas of the piezo actuator being cooled differently.

[0040] In the dosing system according to the invention, the cooling medium can continuously absorb heat as it flows through the groove(s) or heat up through contact with the bellows of the module housing wall. The heat generated at the piezo actuator during operation within the module housing wall, which is conducted outwards from the piezo actuator by the heat-conducting potting compound, preferably in a lateral or radial direction relative to a longitudinal extent of the piezo actuator, into or onto the module housing wall, can be directly released again via the module housing wall to the outside of the module housing to the cooling medium flowing past. The module housing wall can preferably also have a high thermal conductivity. In this way, the heat can be effectively dissipated or transported away on the outside of the bellows in a continuous flow without overheating or heat buildup. The thus heated cooling medium is finally discharged or discharged again via the outlet opening in the housing.If desired, after it has reached its initial temperature again - either through active or passive cooling - it can be fed or admitted through the inlet opening for further cooling, forming a cooling circuit. Overall, the dosing system can thus be effectively kept below a specified maximum or maximum operating temperature, even during continuous operation, with a temperature of the encapsulated piezo actuator, e.g., a core temperature, preferably being at most 200°C, more preferably at most 160°C, and particularly preferably at most 140°C. At the surface of the piezo actuator, the temperature can preferably be at most 140°C. In addition to the components just described, the dosing system can comprise further components, as described later.

[0041] Advantageously, the actuator module according to the invention can be used particularly profitably in a dosing system, in particular in a jet valve, as described above. In particular, by utilizing the actuator module with the helical wave contour according to the invention in a housing encapsulating the piezo actuator and the cooling system tailored to this purpose in the dosing system, the clock frequency of the dosing substance dispensing can be significantly increased compared to known dosing systems with conventional encapsulated piezo actuators, in which the surface structure of the encapsulation is also not designed helically for cooling purposes.

[0042] Further, particularly advantageous embodiments and developments of the invention emerge from the dependent claims and the following description, wherein the independent claims of one claim category can also be developed analogously to the dependent claims and embodiments of another claim category and, in particular, individual features of different embodiments or variants can be combined to form new embodiments or variants.

[0043] The potting compound can preferably comprise a base compound and an auxiliary material. In particular, after hardening or curing in the module housing interior, the base compound can be a hardened, preferably vulcanized and thus elastic, material. To produce an actuator module, the potting compound is preferably poured into the module housing interior between the piezo actuator and the module housing wall, where it then hardens after a certain time. For example, the components of the potting compound can be provided outside the module housing, e.g., by mixing the base compound and the auxiliary material, and then introduced into the module housing in the form of a flowable compound (potting compound). The base compound can harden in the module housing interior to form the ready-to-use (hardened) potting compound.

[0044] The at least one auxiliary material can be at least particulate, thermally conductive, and dielectric. In particular, the auxiliary material itself is a dielectric. The fact that the auxiliary material is particulate means that the auxiliary material is present as a solid at least in the matrix of the potting compound, and preferably also in the hardened potting compound. For example, the auxiliary material can comprise a plurality of individual auxiliary material particles, auxiliary material platelets, or the like. An “auxiliary material platelet” is understood to mean a flat element or particle that is essentially the same thickness everywhere and is delimited on two opposite sides by a predominantly flat surface (base area) that is comparatively extensive in relation to its thickness. It should be noted that a particular auxiliary material particle can also be configured only approximately as an “auxiliary material platelet.”Accordingly, excipient particles that have slightly different thicknesses within the same particle are also referred to as "excipient platelets." The base surfaces can have different geometries, such as approximately elliptical or circular shapes, whereby the outer contour of a base surface can also be irregular. Accordingly, a "platelet-like" excipient particle, also referred to as an excipient platelet, is defined in particular by the fact that it has two predominantly flat base surfaces, whereby the thickness of the excipient particle (corresponding to the distance between the base surfaces) is many times smaller in relation to the extent of the base surfaces. The potting compound can in principle comprise two or more different types of excipients, e.g. different excipient particles.

[0045] Preferably, the auxiliary material can be arranged in the potting compound in the module housing, preferably also in the base compound in the housing, such that heat is dissipated via the potting compound, in particular via the auxiliary material in the potting compound, from the piezo actuator, more precisely the piezo actuator surface, to the module housing wall during operation of the actuator module.

[0046] Preferably, an inherent thermal conductivity of the excipient, i.e. a thermal conductivity of the excipient itself, can be at least about 2.5 W / (m K), preferably at least about 30 W / (m K), more preferably at least about 50 W / (m K), more preferably at least about 100 W / (m K), more preferably at least about 200 W / (m K), particularly preferably at least about 300 W / (m K), in particular at least about 400 W / (m K). The aforementioned values ​​can preferably relate to the thermal conductivity of an excipient that is in the form of a solid block of material, e.g. a massive block of excipient. The thermal conductivity or the thermal conductivity coefficient is understood, as is generally customary, to be a material property of the excipient that determines the heat flow through a material or the excipient on the basis of thermal conduction.

[0047] Preferably, a powder-like auxiliary material, in particular (still) outside the potting compound, can have an (inherent) thermal conductivity of at least about 1 W / (m K), preferably at least about 2 W / (m K), preferably at least about 3 W / (m K), more preferably at least about 4 W / (m K), more preferably at least about 5 W / (m K). The powder-like auxiliary material can preferably be boron nitride and / or comprise boron nitride.

[0048] The thermal conductivity of the base material (without auxiliary material), e.g. a silicone gel, is preferably at least 0.08 W / (m K), preferably at least 0.15 W / (m K), in particular at least 0.2 W / (m K).

[0049] During operation of the actuator module, heat can be dissipated by means of the heat-conducting, dielectric auxiliary material arranged in the base material, in particular from a surface of the piezo actuator, essentially uniformly along an entire longitudinal extent of the piezo actuator, in particular in a lateral direction. Preferably, the heat dissipated by the piezo actuator can largely be transferred via the potting compound to a module housing shell of a module housing wall, as will be described later. The auxiliary material, in particular the auxiliary material particles or auxiliary material platelets, can preferably be arranged for the most part in such a way that a longitudinal extent of a respective auxiliary material particle or auxiliary material platelet runs transversely, preferably essentially orthogonally, to a longitudinal extent of the piezo actuator in the module housing. Particularly preferably, the auxiliary material particles orAuxiliary material plates are arranged in the potting compound in such a way that their longitudinal extension corresponds to the shortest distance between a piezo actuator surface and the module housing wall.

[0050] The longitudinal extension of the piezo actuator is understood to be the largest or longest extension of the piezo actuator in one direction. The longitudinal extension of the piezo actuator is preferably parallel to the axial direction of the module housing. The longitudinal extension of an auxiliary material plate is understood to be the largest or longest extension of the auxiliary material plate in one direction, in particular along at least one base surface of the auxiliary material plate.

[0051] Advantageously, the special arrangement of the auxiliary material plates in the base material or in the potting compound with respect to the piezo actuator can result in particularly efficient heat dissipation during operation. With piezo actuators, heat emission during operation usually occurs predominantly in a lateral or radial direction outwards due to the layered structure. This means that, with respect to the longitudinal extent of the piezo actuator, heat loss is predominantly dissipated laterally away from a piezo actuator surface, with hardly any heat being dissipated in the axial direction, e.g. towards an actuator front or an actuator end. With encapsulated piezo actuators, it is therefore particularly effective if at least a large part of the heat loss can be dissipated laterally or radially away from the piezo actuator via the auxiliary material plates in the base material, especially since a lateral region of a piezo actuator makes up a relatively large part of the entire surface of the piezo actuator.

[0052] In combination with the features already mentioned above, including the at least one helical section of the wave contour of the module housing wall, the heat which is conducted from the piezo actuator into the module housing wall during operation can be effectively dissipated from the dosing system by the actuator module, thus further improving overall heat dissipation.

[0053] The base material of the potting compound can preferably comprise a silicone, in particular a silicone gel, to provide a cured or curable substance. The silicone gel can preferably comprise at least one base silicone and a crosslinking agent. The base silicone can be, for example, a silicone of the type SG 75L2-30, with a type SG 79L5-30 being used as the crosslinker (manufacturer: Elantas, Germany). Alternatively, at least one polyurethane or another suitable silicone could be used instead of silicone, whereby the basic components of the base material should preferably have at least the insulation and thermal conductivity values ​​mentioned above.

[0054] The auxiliary material can preferably be boron nitride (BN). The auxiliary material can particularly preferably be hexagonal boron nitride (α-boron nitride). Hexagonal boron nitride (α-BN, hexagonal) consists of layers of a planar, hexagonal honeycomb structure in which the B and N atoms occur alternately and is otherwise generally known. The boron nitride as an auxiliary material can particularly preferably be in powder form with a pronounced crystal structure before processing. In particular, the boron nitride can be in the form of platelet-shaped individual crystals before processing and / or in the hardened matrix. Particularly preferably, each individual (BN) crystal can form one auxiliary material particle or one auxiliary material platelet. In particular, a combination of boron nitride with the hardenable matrix ensures particularly effective heat dissipation, e.g.if these are cast together in the module housing interior and the boron nitride is suitably aligned or oriented with its longitudinal extension in the direction of the nearest module housing wall section before the silicone hardens.

[0055] Preferably, the helical section can begin in the axial direction at a distance, i.e. spaced apart, from a respective end face of the module housing and extend from there at least partially in the axial direction to the other end face, in particular in the direction of an opposite end face. Particularly preferably, the respective helical section can extend at least to the middle of the bellows (relative to the axial direction of the module housing). Preferably, a first end face of the module housing can comprise a base surface of the cylindrical module housing, in particular be formed thereby. Preferably, a second end face of the module housing can comprise an opposite cover surface of the cylindrical module housing, in particular be formed thereby.Preferably, the module housing wall of the module housing can have flat or smooth, i.e. freely extending, sections in a respective end region near the respective end face adjacent to the helical section. This means that the bellows extends freely in sections at both ends, i.e. in a region near an axial end face of the module housing, or is freely extending, i.e. smooth. In this way, both the inlet opening and the outlet opening can be arranged at any azimuthal position or contact surface to the bellows in front of an end section or end region thereof in the recess of the dosing system. Consequently, the exact alignment of the bellows, i.e. how it is positioned rotated about its axis of rotation in the recess in the dosing system, can normally be less important, i.e.In this respect, it can be arranged rotated around its longitudinal axis in the recess of the housing of the dosing system, provided that its electrical connections do not specify a specific orientation.

[0056] There are various options for the shape and design of the shaft contour or helix. In principle, the bellows can, for example, have a continuous helix (in other words, a cylindrical spiral or thread), i.e., a right-handed or left-handed thread or a right-handed or left-handed helix extending substantially across its entire length. Preferably, the helical section can have at least one thread spiral. The thread spiral is preferably formed by the housing wall.

[0057] The bellows can preferably have at least two counter-rotating helical sections in the axial direction. For example, the bellows can have two helical sections, each with a groove, with the grooves being designed in opposite directions. "Counter-rotating" here means that the sections, e.g., the grooves, have a different winding direction, sometimes also referred to as a pitch or spiral direction. Thus, with two counter-rotating helical sections, one section has a right-hand thread and the other a left-hand thread. The bellows can preferably have two thread spirals with different spiral directions.

[0058] When the actuator module is installed in the dosing system, this allows the cooling medium to be transported equally to the ends of the bellows via the coils of the corrugated bellows, particularly if an inlet opening for the cooling medium is assigned to a central area of ​​the corrugated bellows, whereby in this way practically half of the generated heat can be dissipated. It is therefore particularly advantageous that where a piezo actuator typically experiences the greatest heating, namely halfway along its length, i.e. in the middle, the actuator module is supplied with freshly cooled cooling medium, e.g. with a (target) output temperature, and the actuator module is therefore cooled particularly strongly there, whereby the cooling performance may decrease slightly towards the two ends (where the piezo actuator is also typically less heated). Such a corrugated bellows would therefore be ideally matched to the heat dissipation or heat loss profile of the piezo actuator.

[0059] Regardless of this, the two helical sections with opposing winding directions offer another advantage. They prevent the bellows from accidentally twisting, deforming, or distorting over time due to torsional forces under high operating loads due to a wave contour that is continuously wound in one direction, which would then no longer allow precise dosing. With two opposing sections, half the torsional moment is generated in each of the two sections compared to a continuous or uniform section. However, the two generated torsional moments do not add up to the total torsional moment mentioned above; rather, they largely or completely cancel each other out due to the opposing winding directions and the associated opposing effective or rotational directions.

[0060] Preferably, at least two of the helical sections can be separated from each other, particularly preferably with opposing winding directions. In this case, the cooling medium can be discharged from a different groove than the one into which it was initially introduced. The discharge could thus occur in a first groove that is separated or interrupted from the second groove, from which the cooling medium is then discharged, by a groove-free shell section.

[0061] Preferably, the at least two, preferably separate, helical sections can be separated from one another by a flat or smooth section. The flat section is preferably formed by the module housing wall. In principle, the two helical sections can have the same winding direction. However, it is preferred that the two helical sections have opposite winding directions. Accordingly, the two helical sections can preferably each have a thread spiral with a different winding direction. Preferably, the helical sections can each extend from the flat section in the axial direction to the ends or front sides of the module housing. This can be advantageous if multiple inlet openings and / or outlet openings are provided in the housing of the dosing system.

[0062] Particularly preferably, the flat section can be arranged in the center of the bellows, and two helical sections can each extend outward from there to the two opposite ends of the bellows, in particular in each case in the direction of an end face of the module housing. In this case, for example, cooling medium could then be introduced through inlet openings at both ends, e.g., near the end faces, and discharged in the center through an outlet opening, or, as is preferred, vice versa, i.e., the cooling medium could be admitted into the recess in the dosing system at the level of the center of the bellows and discharged or discharged again at the level of the two ends of the bellows.

[0063] To ensure a secure seal between the outer surface of the bellows and the inner surface of the recess in the dosing system housing (e.g., if the components are not precisely matched or supportive), an annular sealing element, such as an O-ring, can be arranged at least in the area of ​​one end of the bellows. With such a sealing element at each end of the bellows, the cooling medium always remains in an area between or within the sealing elements when it is admitted within them, so that there is no risk of the cooling medium getting into other areas of the dosing system, e.g., by unintentionally escaping from the top of the housing along the walls along the recess or on the bellows, or by unintentionally penetrating the area of ​​a lever and / or ejection element at the bottom - if undesired.

[0064] A respective sealing element contact section of the inner surface of the recess, where the respective sealing element seals the bellows radially inward and the recess radially outward, can preferably be directly adjacent to the inlet and / or outlet openings. This has the advantage that no dead center is created on the sealing element itself, where cooling medium could otherwise potentially accumulate or build up if the cooling medium is admitted or discharged some distance away.

[0065] There are various options for the design of the corrugated contour, in particular the elevations and depressions, e.g., the groove-like depression. Preferably, at least one of the helical sections of the corrugated bellows can have a pitch of preferably at least 1 mm, more preferably at least 5 mm, and most preferably at least 10 mm.

[0066] Alternatively or additionally, at least one of the helical sections of the bellows can have a pitch of preferably no more than 35 mm, preferably no more than 20 mm, particularly preferably no more than 15 mm. Preferably, at least one groove of a helical section can have the aforementioned pitch. The term "pitch" here refers to the same pitch as is used and specified for a screw thread.

[0067] There are also various options for the design of the dosing system, especially the recess.

[0068] Preferably, the recess of the dosing system can have at least one radial inlet opening.

[0069] Alternatively or additionally, the recess of the dosing system can have at least one radial outlet opening. The respective inlet or outlet opening can be arranged, in particular, radially with respect to the cylindrical recess in the housing. Preferably, the respective radial inlet or outlet opening can be configured substantially orthogonal to a longitudinal extent or longitudinal direction of an assembled housing module, in particular transversely to the axial direction of the housing module.

[0070] In an actuator module with a module housing installed in the dosing system, the radial inlet opening and / or the radial outlet opening can particularly preferably be located substantially at the level of an upper end section of the module housing. The upper end section can preferably face away from the discharge direction of the dosing substance from the dosing system.

[0071] Alternatively or additionally, the radial inlet opening and / or the radial outlet opening can be located at a level with a lower end section of the module housing. The lower end section can preferably face an ejection direction of the dosing substance from the dosing system. Preferably, at least one of the walls that axially delimits the recess of the housing, i.e., at least partially axially delimits it, can have an inlet opening or an outlet opening. An axial delimitation of the housing preferably refers to the axial direction of the installed module housing, i.e., a delimitation toward the end faces of the module housing.

[0072] Alternatively, one of the walls which axially delimits the recess in the housing can preferably have an inlet opening and the other, opposite wall can have an outlet opening. In this way, the cooling medium can be introduced into a groove in the bellows in a region close to an axial end face or end surface of the module housing from an axial direction, e.g. approximately parallel to a longitudinal extent of the module housing, and can be discharged from a groove in the bellows in a region close to the opposite, other, axial end face or end surface of the module housing. This design has the particular advantage that the entire cooling system, including the supply and removal of the cooling medium, can be accommodated in the installation space of the cross-sectional area of ​​the actuator module, i.e. in the axial extension of the piezo actuator, and thus a corresponding dosing system orDosing valve can be designed to save space, which is a great advantage especially in parallel applications, for example with dosing systems with several dosing systems arranged in parallel, since the dosing systems can be arranged close to one another and the nozzles are therefore very close to one another.

[0073] At this point, it should be noted that it is also possible for the recess to be widened radially (at least over certain sections) around the area of ​​the end section of the bellows, so that the cooling medium can be introduced from an axial direction past the end section of the bellows through the widened section(s) of the recess into the groove on the outside of the bellows, as will be explained in more detail below using an exemplary embodiment.

[0074] Preferably, in the case of a properly installed actuator module, the recess in the dosing system can have an inlet opening in the middle, i.e. on a center plane as seen in the axial direction of the module housing, between the end faces of the module housing of the actuator module in a radial wall, for introducing the cooling medium, e.g. from a radial direction, into the recess. The cooling medium can preferably be introduced in such a way that the surface of the bellows is exposed to cooling medium. The radial wall of the recess preferably faces the bellows and / or extends parallel to the longitudinal direction of the module housing. Preferably, in the case of a dosing system with a transmission mechanism which is arranged in a further recess between the piezo actuator and the ejection element, an outlet opening can be arranged in the region of the transmission mechanism. The outlet opening in the region of the transmission mechanism enables through- or out-flow of cooling medium.Airflow around the components of the transmission mechanism, such as the transmission lever, so that any abrasion that may occur during operation can be directly removed and the components can be at least slightly cooled at the same time.

[0075] Alternatively or additionally, an outlet opening can be arranged in the area of ​​the ejection element. This additionally enables cooling and cleaning of at least parts of the ejection element.

[0076] Alternatively or additionally, at least one inlet opening can be formed at an axial end region of the bellows, preferably in the region of, for example, an upper end face of the module housing, for introducing the cooling medium, which again enables, among other things, a very space-saving design of the dosing system. In this way, the entire actuator module can be cooled from one end of the bellows, in particular from one end of the module housing, to the transmission mechanism in the region of the ejection element and, in particular, as already mentioned, material abrasion generated during operation can be blown out or flushed out of the transmission mechanism. In this case, it may be advisable to treat, clean, or filter the cooling medium accordingly if it is to be reused after cooling, which is seen as desirable in terms of sustainability.

[0077] Particularly preferably, the inlet opening can be formed at an axial end region of the bellows for introducing the cooling medium from an axial direction. This makes it possible to achieve a particularly compact arrangement of housing, cooling medium supply, and actuator module, since no lateral supply bores and / or connections are required, thus reducing the lateral space requirement of the dosing system. This is particularly advantageous when a high packing density of several closely arranged dosing systems is required or desired. Preferably, an inflow direction of the cooling medium can be parallel to a longitudinal direction of the module housing. For example, an axially extending bore can be formed in the form of a recess at the edge of an upper end face of the module housing or in the form of a cutout through a cover plate of the module housing along an outer side of the module housing wall to the bellows on the actuator module.

[0078] Preferably, particularly preferably in a dosing system with an inlet opening at an end region of the bellows at the end of the piezo actuator, the housing can have a further recess on the front side of the piezo actuator, particularly preferably extending transversely thereto. The further recess can, for example, adjoin the piezo actuator and / or the recess for the actuator module in an ejection direction (of the dosing substance). A transmission lever can be arranged in the further recess, which transmits the longitudinal extension of the piezo actuator, in particular a change in the longitudinal extension, via a lever arm of the transmission lever to the ejection element of a spring-mounted plunger device. The transmission lever can, for example, be asymmetrical.

[0079] The plunger device typically projects with the ejection element into a nozzle of a fluidic unit of the dosing system, which nozzle is supplied with a dosing medium by the fluidic unit.

[0080] The outlet opening for the cooling medium can preferably be arranged in the area of ​​the further recess near the spring-mounted plunger device. Thus, the cooling medium introduced at the end of the piezo actuator at an inlet opening of the housing at the end of the bellows, e.g., in the area of ​​a front side facing away from the discharge direction, can flow through and cool the entire dosing system, in particular the actuator module, including the further recess.

[0081] The invention is explained in more detail below with reference to the accompanying figures using exemplary embodiments. In the various figures, identical components are provided with identical reference numerals. The figures are merely schematic and are not to scale. They show:

[0082] Figure 1 is a roughly schematic cross-sectional view through an embodiment of a dosing system according to the invention with a built-in actuator module according to the invention,

[0083] Figure 2 is a roughly schematic sectional view along a section line AA through the dosing system from Figure 1, Figure 3 is an isolated, side view of the actuator module from Figure 1 and Figure 2,

[0084] Figure 4 is a roughly schematic sectional view of parts of the dosing system from Figure 2 with a slightly modified version of the installed actuator module, according to an analogous section line A'-A' through the dosing system,

[0085] Figure 5 is an isolated, side view of an actuator module from Figure 4 which is slightly modified compared to the actuator module from Figure 3,

[0086] Figure 6 is a roughly schematic sectional view of parts of an embodiment of a dosing system according to the invention with an actuator module according to the invention along an analogous section line A-A through the dosing system,

[0087] Figure 7 is an isolated side view of the actuator module from Figure 6,

[0088] Figure 8 is a roughly schematic sectional view of a variant of the dosing system from Figure 6, which is adapted to a slightly modified variant of the installed actuator module, along an analogous section line A"'- A"' through the dosing system,

[0089] Figure 9 is an isolated, side view of an actuator module from Figure 8 which is slightly modified compared to the actuator module from Figure 6,

[0090] Figure 10 is a roughly schematic sectional view of parts of an embodiment of a dosing system according to the invention with the actuator module from Figure 4, according to an analogous section line A"-A"" through the dosing system,

[0091] Figure 11 is an isolated, side view of an actuator module slightly modified from the actuator module in Figure 10,

[0092] Figure 12 is a roughly schematic sectional view of another actuator module, wrapped in an expandable, tight cover, which comprises a supply hose and a discharge hose for cooling medium, Figure 13 is a roughly schematic sectional view of the actuator module from Figure 12, this time with a cover without supply and discharge hoses.

[0093] As mentioned, the actuator module described above can be used, for example, in a dosing system for dosing liquid to viscous dosing materials, e.g., in a jet valve, which is shown purely schematically and in section in Figure 2. Since the basic structure of such jet valves is known, only the main elements are described below.

[0094] The dosing system 50, which is shown in cross-section in Figure 1 and in longitudinal section in Figure 2, comprises, as essential components, an actuator assembly 51 and a fluidic assembly 52 detachably coupled thereto, wherein the coupling is effected here, for example, via two screws 62. The actuator assembly 51 essentially comprises all components that ensure the drive or movement of an ejection element 53a or a plunger 53a of a plunger device 53 of the fluidic assembly 52 in a nozzle 54.

[0095] In addition to the nozzle 54 and a feed channel 56 for dosing substance D to the nozzle 54, the fluidic assembly 52 comprises all other parts that are in direct contact with the dosing substance D, as well as the elements that are required to assemble the respective parts that are in contact with the dosing substance D or dosing medium D or to hold them in their position on the fluidic assembly 52.

[0096] In the embodiment of the dosing system 50 shown here in Figure 2 (as well as in the other embodiments shown), the actuator assembly 51 comprises a housing 57, more precisely a housing block 57, with two internal chambers 58, 59, namely on the one hand an actuator chamber 58 with an actuator module 1 located therein with at least one piezoceramic actuator 2 hermetically encapsulated in a module housing 3 (Figure 2), and on the other hand an action chamber 59, into which a movable ejection element 53a, here a plunger 53a, of the fluidic assembly 52 projects.Via a transmission mechanism 60 comprising a lever 63, which extends essentially horizontally from an area in the action chamber 59 below the actuator chamber 58 into an area of ​​the action chamber 59 above the tappet device 53, the tappet 53a is actuated by means of the actuator module 1 such that the dosing substance D to be dosed is ejected by the fluidic assembly 52 in the desired quantity at the desired time via the nozzle 54 in an ejection direction AR. The tappet 53a closes a nozzle opening 55 and thus also serves as a closure element 53a. However, since the majority of the medium is only ejected from the nozzle opening 54 by the tappet 53a when the tappet 53a moves towards the nozzle opening 55 in the ejection direction AR, it is referred to here as the ejection element 53a.

[0097] To control the piezo actuator 2 (Figure 2), the actuator module 1 is electrically or signal-wise connected to a control device 5, which can also be configured, for example, as part of the dosing system 50. The connection to the control device 5 is made via connecting cables 5', which are connected at their ends to actuator module control connections 7a, e.g., suitable connectors 7a.

[0098] The actuator module control terminals 7a each contact an electrical terminal 6a in the module housing 3, here two contact pins 6a, each of which is hermetically sealed and electrically insulated through a module housing wall 3w of the module housing 3. In Figure 1, the actuator module 1 comprises a total of four contact pins 6a, 6b, which are arranged in a front side 12 or end side 12—also referred to as the module housing cover—of the module housing 3 (see Figure 3). The two outer contact pins 6a here serve to control the piezo actuator 2 and the communication between the piezo actuator 2 and the control device 5.

[0099] The two contact pins 6b shown in the center here are used to transmit measured values ​​from temperature sensors in the module housing 3 to the control device 5. For this purpose, the contact pins 6b are connected, on the one hand, via temperature sensor connections 7b, to the control device 5 via connecting cables 5', and, on the other hand, to the individual temperature sensors in the module housing 3 (not shown here). For example, measured values ​​from multiple temperature sensors could also be transmitted to the control device 5 in a spatially resolved manner via the contact pins 6b.

[0100] The piezo actuator 2 (Figure 2) arranged in the module housing 3—and above it also the module housing 3—can expand and contract in the longitudinal direction of the actuator chamber 58 according to a wiring by means of the control device 5. The actuator module 1 can be inserted into the actuator chamber 58 from above and mounted therein in a height-adjustable manner, enabling precise adjustment of the actuator module 1 with respect to a movement mechanism with a transmission mechanism 60. In the case shown here, the module housing cover or end face 12 (Figure 3) is supported on the inside of the actuator chamber 58 via a support element (not shown in detail). The support element serves as the upper abutment here and can be adjusted, for example, by a screwing movement (not shown) for adjustment of the actuator module 1.Accordingly, the actuator module 1 is mounted downwards on the lever 63 via a pressure piece 64 tapered at the bottom at an acute angle. The lever 63, in turn, rests on a lever bearing 65. Via this lever bearing 65, the lever 63 can be tilted about a tilting axis K, so that a lever arm of the lever 63 extends through the action chamber 59. At the end of the lever arm, it has a contact surface 66 pointing toward the plunger 53a of the fluidic assembly 52 coupled to the actuator assembly 51, which contact surface presses against the contact surface 67 of the plunger head 68.

[0101] In all of the embodiments shown, it is provided that the contact surface 66 of the lever 63 is permanently in contact with the contact surface 67 of the plunger head 68, in that a plunger spring 69 presses the plunger head 68 from below against the lever 63. In principle, however, it would also be possible for a distance to exist between the plunger 53a and the lever 63 in an initial or rest position of the plunger spring 69. To enable a nearly constant preload of the drive system, the lever 63 is pressed upwards here by an actuator spring 70 at the end where it comes into contact with the plunger 53a.

[0102] The plunger 53a is supported by the plunger spring 69 on a plunger bearing 71, to which a plunger seal 72 is connected at the bottom. The plunger spring 69 pushes the plunger head 68 upwards away from the plunger bearing 71 in the axial direction. This also pushes a plunger tip 73 away from a sealing seat 74 of the nozzle 54. This means that without external pressure from above on the plunger head 68, a nozzle opening 55 is also unclosed in the resting (non-expanded) state of the piezo actuator 2 (Figure 2).

[0103] The dosing material D is supplied to the nozzle 54 via a nozzle chamber 75 and an adjoining feed channel 56, which can be connected to a dosing material supply line 76 to a dosing material reservoir (not shown here).

[0104] The dosing system 50, more precisely the housing block 57, further comprises - as shown in Figures 2, 4, 6, 8 and 10 by way of example and schematically at different positions in the dosing system 50 - inlet openings 58i ra d, 58i ax and outlet openings 58o ra d, 59o of a (not shown) controllable cooling device, which openings have a direct or indirect connection to a bellows 10, 20, 30, 40 of the actuator module 1. Via the respective inlet openings 58i ra d, 58i ax a cooling medium M, e.g. air M, in particular compressed air or pre-cooled compressed air, can be introduced from the outside at a desired location, e.g. into the actuator chamber 58.

[0105] Figure 2 shows that a cooling medium M is introduced via a radial inlet opening 58i ra d flows into the actuator chamber 58, which inlet opening 58i ra d essentially at a height h eof an upper end section of a bellows 10 of the actuator module 1. Consequently, the cooling medium M flows into the actuator chamber 58 in a region between an upper end face 12 and a lower end face 11 (Figure 3) of the module housing 3 and hits at height h efor the first time onto the bellows 10 (Figure 2). Due to the helical structure of the housing wall 3w, the inflowing cooling medium M is guided through a groove 17, which is delimited by two elevations 18, along the outer surface of the bellows 10 and flows around the surface in a targeted manner in the helical region. It can be seen that the respective elevations 18 are essentially flush with a wall 58w or an inner surface 58w of the actuator chamber 58 of the dosing system 50. This allows a directed flow of cooling medium M to be generated along the groove 17. Through contact with the jacket surface of the bellows 10, the cooling medium M absorbs heat which is generated during operation in the piezo actuator 2 or is present on the piezo actuator surface 2' and is transferred via the potting compound 4, in particular via the auxiliary material 4b in the base compound 4a, in the module housing interior 3i (Figure 2) to the module housing wall 3w orthe jacket surface of the bellows 10 and guides it away from the actuator module 1. This allows the bellows 10 to be effectively cooled. After the cooling medium M has completely passed the jacket surface of the bellows 10 along the groove 17, it is discharged via a radial outlet opening 58o. ra d again from the actuator chamber 58, blown out or sucked out. The outlet opening 58o ra d is located essentially at a height hf of a lower end section of the bellows 10 of the module housing 3. The flow direction of the cooling medium M through the dosing system 50 is shown schematically by means of arrows. Furthermore, Figure 2 shows the orientation of the radial inlet opening 58i using a schematic coordinate system. ra d and the radial outlet opening 58o rad with respect to the axial direction RAX and the radial direction RRAD ÜBS of the module housing 3 or the actuator module 1. In the cross-section in Figure 1, the axial direction RAX running in the viewing direction is schematically shown as the center of the actuator module 1, with the radial direction RRAD running perpendicular to it. Figure 1 also schematically shows an azimuthal direction RAZ.

[0106] The heated cooling medium M emerging from the actuator chamber 58 can, if required, be fed back to a cooling device for cooling down and then fed back via the inlet opening 58i ra d to be used for further cooling. Such a circuit with a heat exchanger for dissipating the absorbed heat can be seen as an alternative to compressed air cooling, in which the compressed air used is usually not reused afterward.

[0107] The actuator module 1 from Figure 2 is shown in detail in Figure 3, with the bellows 10 being constructed such that a single groove 17 extends continuously or continuously over the entire length of a helical section 14. The helical section 14, or its beginning, is arranged at a distance a from the end face 12. In the example shown here, the opposite end of the helical section 14, which faces the end face 11, forms an annular elevation.

[0108] The module housing 3 in Figure 3 is designed such that, in the assembled state (Figure 2), the cooling medium M directed onto or impinging on the grooved surface of the bellows 10 flows through a groove 17 extending or winding helically in a winding direction WRAX.AZ along the bellows 10. This groove 17 is laterally delimited by parallel elevations 18 running on both sides of the groove 17. The groove 17 has a groove width 17b of preferably 1 mm, with the respective elevation 18 having a elevation width 18b of preferably 1 mm. A pitch 19s of the bellows 10 is accordingly 2 mm in this example. The module housing 3 further comprises an upper front-side annular flange 16 and a lower end-side annular flange 15.

[0109] Figures 4 and 5 show an embodiment of an actuator module 1 with a bellows 20 modified compared to Figure 3, wherein the helical section 14 is arranged at a distance a2o from the upper end face 12 of the module housing 3. Pointing toward the end face 12, the helical section 14 borders on a flat or winding-free section 22 or merges into a flat region 22. Accordingly, the housing 3 does not have a terminal annular elevation in which the groove ends (unlike Figure 3). Rather, the groove 17 opens into the flat section 22. The advantage of this design with a freely running helical section opening into a flat section 22 is that the flow of the cooling medium can be directed essentially to any desired location along the circumference of the flat section 22, wherein the flow of cooling medium flows automatically into the beginning groove 17.In contrast, in the groove 17 of the bellows 10 shown in Figure 3, which is defined by the annular elevation in the form of a "flange," a clear (target) entry point for the cooling medium into the groove 17 is defined. If the cooling medium is introduced at precisely this point, it automatically flows into the groove 17 and along the groove 17 to the end of the helical section 14. However, if the cooling medium is only introduced into the groove 17 at a later point, a "dead" section may arise in which cooling medium may accumulate or build up.

[0110] In the case of the bellows 10 (see Figures 2 and 3) and the slightly modified bellows 20 (see Figures 4 and 5), it is advantageous if, as is the case here in Figures 2 and 4, the outlet opening 58o ra d at the opposite end section of the bellows 10, 20 as seen in the axial direction RAX (Figure 2) than the inlet opening 58i rad, since then almost the entire bellows 10, 20 is cooled. As shown in Figures 2 and 4, there is an inlet opening 58i ra d in the area of ​​an end section of the bellows 10, 20 shortly before an annular flange 16, 26 (Figures 3 and 5) near the end face 12 of the module housing 3. An outlet opening 58o ra d is arranged in the area of ​​the opposite, other end section of the bellows 10, 20 just before an annular flange 15, 25 (Figures 3 and 5) near the front side 11 of the module housing 3 in the assembled state (Figures 2 and 4). Both openings 58i ra d, 58o rad each open radially outwardly in relation to the mounted bellows 10, 20 in the region of a jacket surface section on the bellows 10, 20 and extend from there in a radial direction RRAD of the respective bellows 10, 20, which corresponds to the radial direction RRAD of the respective actuator module 1, through and ultimately out of the housing block 57 of the dosing system 50 to the cooling device.

[0111] Both the radial inlet opening 58i ra d as well as the radial outlet opening 58o ra d are located in Figures 2 and 4, each exemplary in the azimuthal direction RAZ of the bellows 10, 20 on a right side of the housing block 57.

[0112] The bellows 20 shown in Figure 4 (and also in Figure 10 in an embodiment of the dosing system 50 explained further below) differs, as already explained, only slightly from the bellows 10 in Figure 3. The difference lies in the design of the shaft contour 10, 20 of the end sections in front of the end faces 11, 12 of the module housing 3 of the respective bellows 10, 20. The shaft contour 10 ends at the bellows 10 in front of the respective annular flange 15, 16 with a groove 17 which closes off to form an annular seal 61 (see Figure 2), i.e. the end of the groove 17 is delimited by the elevation 18. In other words, the helical section 14 of the shaft contour 10 ends at both opposite ends with an annular elevation section as part of an elevation 18 and is thus opposite the respective annular flange 15, 16 (which, in the installed state of the actuator module 1, is closed off from an annular seal 61 to the front face 11 ora ring seal 61 to the end face 12 of the module housing 3 serves as a stop).

[0113] In contrast, in the housing module 3 in Figures 4 and 5, the groove 17 at the respective end of the helical section 14 (shown here, for example, with a left-handed helix or turn) in the bellows 20 runs freely to the respective ring seal 61 (see Figure 4) into a wider, flat section 21, 22, which lies just before an annular flange 25, 26 and begins at a distance a2o from the upper end face 12 (Figure 5). The lower annular flange 25 in Figures 4 and 5 protrudes less than the annular flange 26 at the other, opposite end section. This means that the elevation 18 delimiting the groove 17 already runs out approximately one turn earlier. In the installed state of the bellows 20, the path to the end faces 11, 12 between the surface of the bellows 20 and the wall 58w or inner surface 58w of the actuator chamber 58 is sealed only by the ring seal 61, but not by the elevation 18 itself (Figure 4).

[0114] In further embodiments of a dosing system 50 according to the invention in Figures 6 and 8, each of which has a properly installed actuator module 1 according to the invention with a bellows 30, 40, two radial outlet openings 580rad are each at height h e , hf of an end section of the bellows 30, 40. Between the outer outlet openings 58o ra d is a radial inlet opening 58i ra d at height h m which is assigned to a central section 33 of the assembled bellows 30 (Figure 6) or at a height h m which is assigned to a central, flat section 43 of the bellows 40 in the housing block 57 (Figure 8).

[0115] The exemplary embodiments of the actuator module 1 from Figures 6 and 8 with the bellows 30, 40 shown in more detail in Figures 7 and 9 differ from the exemplary embodiments already described above (Figures 3 and 5) in that the shaft contour 30, 40 comprises two separate helical sections 34I, 34r (Figure 7) and 44I, 44r (Figure 9) over its axial extent instead of a continuous helical section 14. The respective helical sections 34I, 34r, 44I, 44r of the respective bellows 30, 40 in Figures 7 and 9 are each approximately half as long as the continuous helical section 14 of the bellows 10 of the actuator module 1 in Figure 3. They each extend from a central section 33 (Figure 7) or from a flat central section 43 (Figure 9) to the end sections of the respective bellows 30, 40.

[0116] In the bellows 30 in Figure 7, the helical section 34I ends with an annular elevation 18 shortly before an end-side annular flange 35, which again serves as a stop for an annular seal 61 (see Figure 6), near the front of the bellows 30. The other helical section 34r at the other end region ends shortly before a front-side annular flange 36 near the end face 12, in particular at a distance a3o from the end face 12 of the module housing 3 of the bellows 30. In the central section 33, the two grooves 17 of the two helical sections 34, 34r meet or intersect exactly at an end point or dead center. The two helical sections 34I, 34r and thus also the respectively associated grooves 17 have a different winding direction (Figure 7).

[0117] In Figure 6 it can be seen that in the assembled state of the actuator module 1, the inlet opening 58irad of the dosing system 50 is directed towards a division point slightly offset from the dead center or intersection point of the two grooves 17 described with reference to Figure 7, which is located approximately a quarter turn in the azimuthal direction RAZ before this dead center, at which dead center the two helical sections 34I, 34r divide into two grooves 17. Due to the positioning of the inlet opening 58i shown in Figure 6 ra d and the actuator module 1 to each other, it is achieved that the cooling medium flows equally into both grooves 17 and along these in the direction of the outlet openings 58o ra d flows and as little cooling medium as possible flows in the opposite direction to the end or dead center of the two grooves 17.

[0118] The bellows 40 in Figure 9 comprises two helical sections 44I, 44r with different winding directions, whereby the two grooves 17 also have different spiral directions. In this bellows 40, a (here lower) helical section 44I runs at the end section of the bellows 40 into a short, flat or winding-free section 41 (without elevation), which is delimited by an annular elevation running purely in the azimuthal direction RAZ, to which a positioning groove for an annular seal 61 (see Figure 8) adjoins the front side (i.e. on the side of the elevation facing the front side), which in turn is delimited by an annular flange 45 (near the front side of the bellows 40) as a stop to the front side. The other helical section 44r at the other end region of the bellows 40 is of identical design.There, the helical section 44r merges at a distance a4o from the end face 12 of the module housing 3 of the bellows 40 into a flat or winding-free section 42, to which an annular elevation is again connected - this time at the end - which in turn is limited at a distance of an annular seal 61 (Figure 8) by an annular flange 46 as a stop to the end face 12.

[0119] In the middle of the bellows 40 in Figure 9, the two helical sections 44I, 44r are separated by the aforementioned central, flat section 43, so that the sections 44I, 44r are spaced apart by a distance b4o. Over the entire distance b4o, the central section 43 is free of grooves and elevations. However, the distance b4o between the sections 44I, 44r can vary along the circumference of the module housing 3. As shown in Figure 8, the actuator module 1 is arranged in the dosing system 50 such that at height h m of the middle section 43 the inlet opening 58ira d is located in the wall 58w of the actuator chamber 58 of the housing block 57, in order to introduce the cooling medium M into the actuator chamber 58 from the right side. In principle, the cooling medium M can also be introduced into the actuator chamber 58 from another side.

[0120] Because the inlet opening 58i ra d in Figures 6 and 8 in the middle between the two outlet openings 58o rad, the area of ​​the piezo actuator 2 (Figure 2) that heats up the most during operation, namely the center, can be cooled the most, since the cooling medium M is introduced there while still freshly cooled. Towards the respective ends, the piezo actuator 2 also usually heats up less during operation, so that increasingly less cooling is required here. Therefore, despite the cooling medium M heating up as a result of the flow around the bellows 30, 40 towards the end areas, sufficient cooling of the piezo actuator 2 can also be achieved at the ends. The degree of cooling or the cooling performance can therefore correlate with the degree of heating of the piezo actuator 2 and thus of the jacket surface of the bellows 30, 40.

[0121] In the actuator modules 1 in Figures 7 and 9, sections 34I, 44I have a left-handed helix or winding direction WRAX, AZ, and sections 34r, 44r have an opposite, right-handed helix or winding direction WRAX, AZ. The oppositely winding sections 34I, 34r, 44I, 44r have the advantage that they halve any torsional forces that may occur during operation of the dispensing system and can also directly cancel each other out due to the opposite winding direction WRAX, AZ. In a cylindrical body, torsional forces can, depending on the material properties and thickness, cause the cylinder to twist with increasing radius and / or increasing length of the threaded section with co-rotating winding. The design-related reduction of this effect expands the possibilities for material selection and material thickness.

[0122] Figure 10 shows a further embodiment of a dosing system 50 according to the invention, in which the cooling medium M is introduced into the dosing system 50 from an axial direction and which does not require the ring seals 61 described, for example, with reference to Figure 4 (if they are present, they merely perform a rough adjustment function for the actuator module 1 in the housing 57). This is because at these locations, the cooling medium M is fed into the bellows 20* at the end through a surface milling in or along the adjacent wall 58w of the recess 58* of the housing 57 of the dosing system 50, ultimately via an axial inlet opening 58i. ax outside past the ring flange 26 of the bellows 20* into a groove 17 of the bellows 20*.

[0123] Figure 11 shows an alternative variant in which the housing 57 surrounding the actuator module 1, more precisely the recess 58 in the housing 57, does not have the mentioned milling, but the upper end section and the annular flange 26 of the bellows 20* have four, here for example concavely drilled or milled, module housing edge recesses 3a through which the cooling medium M reaches or flows into the actuator chamber 58*.

[0124] Specifically, for example, a lateral milling in the form of a concave or hemispherical cutout can be made laterally in the end face 12 and / or the annular flange 26 by means of a ball milling cutter or a drill, so that the cooling medium M from the inlet opening 58i ax or feed bore can reach the helix or helical groove 17 via this lateral widening or these lateral widenings in the wall 58w of the recess 58*.

[0125] It then flows back into or along the helical groove 17 before flowing axially or end-on out of the actuator chamber 58* past the annular flange 25 at the opposite end section of the bellows 20 into an action chamber 59 as a further recess 59, in which, among other things, the lever 63 of a transmission mechanism 60 is located, the structure of the transmission mechanism 60 being described with reference to Figure 2. The axial inlet and outlet of the cooling medium has the particular advantage that the entire cooling with supply and exhaust air can be accommodated in the installation space of the cross-sectional area of ​​the actuator cooling and thus a corresponding dosing system or dosing valve can be designed in a very space-saving, in particular narrow, manner, which is a major advantage, especially in applications with several dosing systems arranged in parallel and close to one another.In addition, the cooling medium M also flows through the action chamber 59 in the area of ​​this transmission mechanism 60, before it is led in the area of ​​the tappet device 53 at the level of the actuator spring 70 or tappet spring 69 through an outlet opening 59o laterally (here to the right) through a bore in the housing block 57 out of the housing block 57, for example into the cooling device (not shown).

[0126] The flow through the inlet opening 58i ax on the end face 12 of the module housing 3 of the bellows 20 up to the outlet opening 59o in the area of ​​the transmission mechanism 60 or the tappet device 53 has the advantage that material abrasion, etc., generated during operation of the dosing system 50 can be directly flushed out of the system. If this is the case, it is advisable to filter the cooling medium M accordingly after each pass, at least if it is reused.

[0127] Figures 12 and 13 now show an actuator module 1 with a tubular, elastic or expandable cover 47. The cover 47 is pulled onto the actuator module 1 once for dosing operation, or alternatively, the actuator module 1 is covered with it. Due to the sheath in the form of the cover 47 around the actuator module 1, the groove 17 of the bellows 20** of the actuator module 1, which is delimited by the lateral elevations 18, becomes a closed, tight, helically extending tunnel through which the cooling medium M can be guided all the way around. The cover 47 comprises an opening at each of its two axial end regions, to which a hose 48, 49 for the cooling medium M is vulcanized. This has the advantage that the housing 57 of the dosing system 50 itself does not have to contain these channels in the form of actual bores.

[0128] The overcoat 47, which sits tightly on the elevations 18, prevents the cooling medium M from skipping or overflowing the elevations 18 perpendicular to the winding direction WRAX, AZ of the groove 17. Furthermore, in the installed state, in which the actuator module 1 with the overcoat 47 is inserted and installed in the dosing system 50, a precisely fitting, almost tight enclosure of the actuator module 1 by the surrounding housing 57 or the actuator chamber 58 in the housing 57 is no longer required. Figure 13 shows a variant of the actuator module 1 from Figure 12, but without the elongated supply hoses 48, 49. For this purpose, corresponding bores or supply hoses are located in the housing of the associated dosing system, although this is not explicitly shown here.

[0129] Due to the interaction of the potting compound 4 with the auxiliary material 4b in the interior of the actuator module 1 with the design of the wave contour 10, 20, 30, 40 on the surface of the actuator module 1 according to the invention as well as the cooling medium inlets and outlets of the dosing system 50, a particularly efficient heat dissipation from the piezo actuator 2 can take place during operation of the dosing system 50, which can have an advantageous effect on the dosing precision and the service life of the piezo actuator 2.

[0130] Finally, it should be noted once again that the devices described in detail above are merely exemplary embodiments that can be modified in a variety of ways by those skilled in the art without departing from the scope of the invention. For example, the actuator modules illustrated in the exemplary embodiments can also be conceived with other pitches and / or winding directions of the helical sections of the bellows. Furthermore, the use of the indefinite articles "a" or "an" does not exclude the possibility that the respective features may be present in multiple instances. Likewise, the terms "element" and "arrangement" do not exclude the possibility that the respective component consists of several interacting subcomponents, which may also be spatially distributed.

[0131] List of reference symbols

[0132] 1 actuator module

[0133] 2 Piezo actuator / actuator

[0134] 2' piezo actuator surface

[0135] 3 module housings

[0136] 3i module housing interior

[0137] 3w module housing wall

[0138] 3a Module housing edge recess

[0139] 4 Potting compound

[0140] 4a Base mass / material

[0141] 4b Excipient

[0142] 5 Control device

[0143] 5' connection cable

[0144] 6a Connection / contact pin (piezo actuator)

[0145] 6b Connection / contact pin (temperature sensor)

[0146] 7a Actuator module control connections

[0147] 7b Temperature sensor connections

[0148] 10, 20, 20*, 20**, 30, 40 Corrugated bellows / corrugated contour

[0149] 11 Front side

[0150] 12 Front side / end side

[0151] 14 section, helical

[0152] 15 Ring flange, end

[0153] 16 Ring flange, front side

[0154] 17 Groove / recess

[0155] 17b groove width

[0156] 18 Survey

[0157] 18b elevation width

[0158] 19s climb

[0159] 21, 22 section, just

[0160] 25, 26 Ring flange

[0161] 33 middle section

[0162] 34I section with left-handed helix

[0163] 34r section with right-handed helix

[0164] 35 Ring flange, end

[0165] 36 Ring flange, front side 41, 42 Section, flat

[0166] 43 middle section, flat

[0167] 44I Section with left-handed helix

[0168] 44r section with right-handed helix

[0169] 45, 46 Ring flange

[0170] 47 overcoats

[0171] 48 Feed hose

[0172] 49 Drain hose

[0173] 50 Dosing system

[0174] 51 Actuator assembly

[0175] 52 Fluidics assembly

[0176] 53 Tappet device

[0177] 53a Ejection or closure element / plunger

[0178] 54 nozzle

[0179] 55 Nozzle opening

[0180] 56 feed channel

[0181] 57 Housing / Housing block

[0182] 58, 58* Recess / actuator chamber

[0183] 58w walls / inner surface of the actuator chamber

[0184] 58iax inlet opening, axial

[0185] 58irad inlet opening, radial

[0186] 580rad exhaust port, radial

[0187] 59 further recess / action chamber

[0188] 59o Outlet opening, further in the area of ​​the ejection element

[0189] 60 Translation mechanics

[0190] 61 Ring seal

[0191] 62 screw

[0192] 63 gear lever / lever

[0193] 64 Pressure piece

[0194] 65 lever bearings

[0195] 66 Contact surface (lever)

[0196] 67 Contact surface (ram head)

[0197] 68 Ram head

[0198] 69 Tappet spring

[0199] 70 actuator spring

[0200] 71 Tappet bearing 72 Tappet seal

[0201] 73 plunger tip

[0202] 74 Sealing seat

[0203] 75 Nozzle chamber

[0204] 5 76 Dosing material feed line a , a20, 830 , 840 Distance 40 Distance / free space between two helical sections he Height / position of an upper end section of the bellows hf Height / position of a lower end section of the bellows0 h m Height / center between the end sections of the bellows

[0205] AR ejection direction

[0206] D Dosing substance / dosing medium

[0207] K Tilt axis

[0208] M Cooling medium I Air 5 RAX Axial direction

[0209] RRAD radial direction

[0210] RAZ azimuthal direction

[0211] WRAX, AZ Winding direction

Claims

Patent claims 1. Actuator module (1) with a hermetically sealed module housing (3) extending longitudinally in an axial direction (RAX), with at least one piezo actuator (2) arranged in the module housing (3) and with electrical connections (6a, 6b) at least for the piezo actuator (2), which connections (6a, 6b) are guided through a module housing wall (3w), wherein a module housing interior (3i) between the piezo actuator (2) and the module housing wall (3w) comprises a potting compound (4) which electrically insulates the module housing wall (3w) from the piezo actuator (2) and which is designed to be thermally conductive, in particular with a thermally conductive auxiliary material, wherein the module housing wall (3w) of the module housing (3) has a bellows (10, 20, 30, 40) with a wave contour (10, 20, 30, 40), wherein at least a section (14, 34I, 34r, 44I, 44r) of the shaft contour (10, 20, 30, 40) is helical in the axial direction (RAX).

2. Actuator module according to claim 1, wherein the potting compound (4) comprises a base compound (4a) and an auxiliary material (4b), wherein preferably the base compound (4a) is a cured material (4a) and the auxiliary material (4b) is at least particulate, heat-conducting and dielectric, wherein the auxiliary material (4b) is arranged in the potting compound (4) in such a way that heat is dissipated from the piezo actuator (2) to the module housing wall (3w) during operation via the potting compound (4), in particular via the auxiliary material (4b).

3. Actuator module according to claim 1 or 2, wherein the helical section (14, 34I, 34r, 44I, 44r) begins in the axial direction (RAX) at a distance (am, a2o, aso, a4o) from a respective end face (11, 12) of the module housing (3) and extends from there at least in sections to the other end face (12, 11), preferably to at least a center of the bellows (10, 20, 30, 40).

4. Actuator module according to one of the preceding claims, wherein the module housing wall (3w) of the module housing (3) has flat sections (21, 22, 41, 42) in a respective end region near the respective end face (11, 12) in each case adjacent to the end of the helical section (14, 34I, 34r, 44I, 44r).

5. Actuator module according to one of the preceding claims, wherein the module housing wall (3w) of the module housing (3) and / or the bellows (20*) has at least one module housing edge recess (3a), preferably four module housing edge recesses (3a), wherein the at least one module housing edge recess (3a) particularly preferably has a concave cross-section.

6. Actuator module according to one of the preceding claims, wherein the bellows (30, 40) has at least two counter-rotating helical sections (34I, 34r, 44I, 44r) in an axial direction (RAX), wherein preferably at least two of the helical sections (34I, 34r, 44I, 44r) are separated from one another, particularly preferably with mutually opposite winding directions (WRAX, AZ).

7. Actuator module according to one of the preceding claims, wherein at least two helical sections (34I, 34r, 44I, 44r) are separated from one another by a flat section (43) which is preferably arranged in the middle of the bellows (40), from which they each extend in the axial direction (RAX) TO the end faces (11, 12).

8. Actuator module according to one of the preceding claims, wherein at least one helical section (14, 34I, 34r, 44I, 44r) of the bellows (10, 20, 30, 40) has a pitch (19s) of at least 1 mm, preferably at least 5 mm, particularly preferably at least 10 mm, and / or at most 35 mm, preferably at most 20 mm, particularly preferably at most 15 mm.

9. Actuator module according to one of the preceding claims with a tubular cover (47), wherein the cover (47) has at least two openings.

10. Dosing system (50) for a dosing substance (D) with a nozzle (54) for dispensing dosing substance (D), a feed channel (56) for dosing substance (D), an ejection element (53a) and at least one actuator module (1) coupled to the ejection element (53a), wherein the dosing system (50) has a housing (57) with at least one cylindrical recess (58, 58*), in which the actuator module (1) according to one of the preceding claims 1 to 9 is inserted, preferably with a precise fit, during dosing operation, wherein the housing (57) has an inlet opening (58i ax , 58i ra d) into the recess (58, 58*) for introducing a cooling medium (M) into a groove (17) on the outside of the Bellows (10, 20, 30, 40) and at least one outlet opening (58o ra d) from the recess (58, 58*) for discharging the cooling medium (M) from a groove (17).

11. Dosing system according to claim 10, wherein the recess (58) of the dosing system (50) has at least one radial inlet opening (58i ra d) and / or a radial outlet opening (58i ra d) which, in the case of an actuator module (1) with a module housing (3) installed in the dosing system (50), is preferably substantially at a height (h e ) of an upper end section and / or at a height (hf) of a lower end section of the module housing (3).

12. Dosing system according to one of the preceding claims 10 or 11, wherein at least one of the walls (58w) which axially delimits the recess (58, 58*) of the housing (57) has an inlet opening (58i ax ) or an outlet opening, or wherein one of the walls (58w) has an inlet opening (58i ax ) and the other has an outlet opening.

13. Dosing system according to one of the preceding claims 10 to 12, wherein the recess (58) in a properly installed actuator module (1) has an inlet opening (58i) centrally between the end faces (11, 12) of the module housing (3) in a radial wall (58w) ra d) for introducing the cooling medium (M).

14. Dosing system according to one of the preceding claims 10 to 13, wherein in a dosing system (50) with a transmission mechanism (60) which is arranged in a further recess (59) between the piezo actuator (2) and the ejection element (53a), an outlet opening (59o) is arranged in the region of the transmission mechanism (60) and / or the ejection element (53a), and / or wherein at least one inlet opening (58i ax ) is formed at an axial end region of the bellows (10, 20, 30, 40) for introducing the cooling medium (M), preferably from an axial direction (RAX).

15. Dosing system according to one of the preceding claims 10 to 14, wherein, preferably in a dosing system (50) with an inlet opening (58i ax ) at an end region of the bellows (10, 20, 30, 40) at the end of the piezo actuator (2), the housing (57) has a further recess (59) at the front of the piezo actuator (2), preferably extending transversely thereto, in which a transmission lever (63) is arranged, which determines the longitudinal extent of the Piezo actuator (2) via a lever arm of the transmission lever (63) to the ejection element (53a) of a spring-mounted tappet device (53), wherein the outlet opening (59o) for the cooling medium (M) is arranged in the region of the further recess (59) close to the spring-mounted tappet device (53).

Images