Integrated motor cassette for connection to and use in a pipetting system, pipetting system, and method for replacing an integrated motor cassette of a pipetting system

Description

[0001] The present invention relates to pipetting systems and their components. In particular, the present invention relates to pipetting systems in which pipetting fluid is aspirated or dispensed via a volume of compressed air.

[0002] Modern pipetting systems are highly complex technical systems. An example of a pipetting system is disclosed in WO 2011 / 083125 A1.

[0003] WO 2014 / 027100 A1 discloses a pipetting device with a piston-cylinder system, comprising a cylinder extending along a cylinder axis, a piston, and a working chamber bounded by the cylinder and the piston and filled with a working fluid, for changing the pressure of the working fluid at a coupling point designed for attaching a pipetting tip, which is pressure-transmitting to the working chamber, by relative movement of the piston relative to the cylinder along a relative path of motion, wherein the piston can be driven by a linear motor for relative movement relative to the cylinder and for this purpose has at least one piston magnet arrangement, and wherein at least one cylinder magnet arrangement is further provided on the cylinder, wherein at least one magnet arrangement consisting of a piston magnet arrangement and a cylinder magnet arrangement comprises a series of electromagnets.which can be energized by means of a control unit of the pipetting device to generate a magnetic field traveling along the path of relative motion in order to provide the magnetic driving force necessary to effect the relative motion, wherein the pipetting device has a magnetic shield radially outside the piston magnet arrangement and the cylinder magnet arrangement, which weakens the magnetic field present radially outside the location of the shield, which emanates from at least one magnet arrangement consisting of a piston magnet arrangement and a cylinder magnet arrangement, compared to a state without shielding.

[0004] Modern pipetting systems are designed to aspirate and dispense very small volumes of liquid at high speed and with high accuracy. They often incorporate a multitude of pipetting tips arranged in a grid to enable multiple pipetting operations to be performed simultaneously. Each individual pipetting tip is driven by its own electric motor for aspiration and dispensing. This results in a complex arrangement intended to deliver high precision and speed in a confined space. Such complex pipetting systems are frequently difficult to maintain.

[0005] Therefore, it would be desirable to provide components for pipetting systems and pipetting systems that simplify maintenance.

[0006] Exemplary embodiments of the invention include an integrated motor cassette according to claim 1, a pipetting system according to claim 10, and a method for replacing an integrated motor cassette of a pipetting system according to claim 14. Further embodiments of the invention are found in the dependent claims.

[0007] Exemplary embodiments of the invention include an integrated motor cassette for connection to and use in a pipetting system, comprising a housing; a guide tube; a piston provided with a plurality of permanent magnets, wherein the piston has a pressure tube-facing side and a pressure tube-away side, wherein the piston is arranged in the guide tube and wherein the piston has at least one seal against the guide tube; and a coil arrangement by which the piston is movable in the guide tube when current is applied to the coil arrangement; wherein the guide tube, the piston and the coil arrangement are arranged in the housing.The integrated motor cassette further comprises a pressure tube connection with which the guide tube on the pressure tube-facing side of the piston can be gas-tightly connected to a pressure tube of the pipetting system; and a power connection which is coupled to the coil assembly and can be connected to a power supply located outside the integrated motor cassette; wherein the integrated motor cassette can be inserted into and removed from the pipetting system as a unit.

[0008] Exemplary embodiments of the invention enable the replacement of an electric motor in a pipetting system as a complete unit. Because the piston with a plurality of permanent magnets, the guide tube, and the coil assembly are arranged in a common housing, the entire assembly of these components can be replaced by a mechanically simple change of the housing. The pressure tube connection and the power connection form two well-defined interfaces through which the integrated motor cassette is supplied with energy on one side and can transmit the pressure generated by the piston to a pressure tube of the pipetting system on the other. Thus, the integrated motor cassette is a comparatively easily replaceable unit that, via its defined interfaces, enables the functions of power supply and the provision of compressed air.This allows the electric motor of the pipetting system to be replaced as an integrated complete unit, significantly simplifying the maintenance of the pipetting system.

[0009] The guide tube on the piston's pressure tube-facing side can be gas-tightly connected to a pressure tube of the pipetting system via the pressure tube connection. In this way, the guide tube of the integrated motor cassette and the pressure tube of the pipetting system, optionally including a connected pipetting tip, form a closed compressed air volume for aspirating and dispensing pipetting fluid. The term "closed compressed air volume" refers to a volume that is sealed on all sides except for the opening in the pipetting tip, if one is connected, or except for the end of the pipetting system's pressure tube intended for connecting the pipetting tip. Thus, the closed compressed air volume has a defined opening through which pipetting fluid can be aspirated or dispensed.

[0010] The coil assembly, guide tube, and pressure tube connection are fixed within the housing of the integrated motor cassette. Consequently, when the integrated motor cassette is connected to a pipetting system, these components have fixed and well-defined positions relative to the rest of the system and can therefore work reliably with the other components.

[0011] The piston is movable within the guide tube. Specifically, the piston can move linearly within the guide tube, moving towards or away from the pressure tube connection. Thus, both the piston and the guide tube each have a side facing the pressure tube and a side facing away from it. Similarly, the housing or the integrated motor cassette itself can also be described as having a side facing the pressure tube and a side facing away from it.

[0012] The pressure tube connection can be part of the guide tube, i.e., form an integrally shaped unit with the guide tube, or it can be a structure attached to the guide tube. In the latter case, the pressure tube connection and the guide tube are gas-tightly connected, so that when connected to the pressure tube of the pipetting system, the closed volume of compressed air described above is formed.

[0013] The coil arrangement comprises a plurality of coils arranged along the guide tube. When current flows through them, the majority of the coils interact with the majority of the piston's permanent magnets. In this way, the piston can be moved quickly and precisely within the guide tube, as is known to those skilled in the art.

[0014] In addition to its ease of mechanical handling, the housing can effectively shield the magnetic field within the integrated motor cassette. The housing can also be used to control the magnetic fields within the integrated motor cassette. For example, magnetic feedback through the housing can occur, thus amplifying the motor's power. This allows for smaller coils and / or a lower current through the coils.

[0015] According to another embodiment, the pressure tube connection is designed to fix the position of the integrated motor cassette relative to the pipetting system. In other words, the pressure tube connection can be configured to align the integrated motor cassette with the pipetting system. In this way, the pressure tube connection not only creates a gas-tight connection to a pressure tube of the pipetting system, but also contributes to the correct positioning of the integrated motor cassette within the pipetting system, thereby enabling the precise interaction between the piston in the guide tube and the compressed air volume in the pressure tube of the pipetting system. As described in detail below, the integrated motor cassette can have additional components for position fixing / alignment besides the pressure tube connection.

[0016] According to a further embodiment, the pressure pipe connection has a receptacle for the motor-facing side of the pressure pipe. The receptacle for the pressure pipe connection can be a recess, in particular a cylindrical recess. It can thus be a hollow cylindrical receptacle on the side of the integrated motor cassette. Such a cylindrical recess is suitable for receiving a cylindrical pressure pipe.

[0017] According to another embodiment, the receptacle has a contact surface for an O-ring arranged around the pressure tube. An O-ring is a relatively simple and effective means of creating an airtight connection between the pressure tube of the pipetting system and the pressure tube connection of the integrated motor cassette, and thus indirectly to the guide tube of the integrated motor cassette. The contact surface of the pressure tube connection for the O-ring can have a circumferential groove that holds the O-ring in position. Alternatively, the O-ring may be provided at a specific location by the design of the pressure tube. In this case, the contact surface for the O-ring can be a partial surface of the receptacle, in particular a partial surface of the cylindrical recess.

[0018] According to another embodiment, the power connection is implemented as a connection board. A connection board is a robust and spatially defined structure that can be easily integrated into the motor cassette and contributes to the overall robust design of the integrated motor cassette.

[0019] According to another embodiment, the connection board is guided inside the housing along the guide tube. In this way, the connection board can be conveniently connected to the multiple coils, which are also arranged along the guide tube.

[0020] According to another embodiment, the connection board is routed through the housing in an end region of the integrated motor cassette facing away from the pressure tube. In this way, the connection of the power supply to the outside of the integrated motor cassette is provided in an area that is easily accessible and not as space-critical as other external areas of the integrated motor cassette. This is particularly relevant when the integrated motor cassette is arranged in a grid next to other similar integrated motor cassettes.

[0021] According to the invention, the integrated motor cassette further comprises a plurality of magnetic field sensors arranged within the housing along the guide tube for determining the piston's position. The majority of these magnetic field sensors are fixed within the housing. The magnetic field sensors can be, for example, Hall sensors. Magnetic field sensors are an effective means of determining the piston's position in the guide tube and, based on this information, controlling and monitoring the piston and thus the aspiration and dispensing of pipetting fluid. By incorporating magnetic field sensors into the integrated motor cassette, this position determination system can also be conveniently replaced along with the electric motor.

[0022] According to another embodiment, the integrated motor cassette also features a sensor data port that is coupled to multiple magnetic field sensors and can be connected to a control unit of the pipetting system located outside the integrated motor cassette. This provides an additional defined interface through which the integrated motor cassette is integrated into the overall pipetting system. The sensor data for determining the piston's position can thus be transmitted from the integrated motor cassette, where a control unit of the pipetting system can centrally control the aspiration and dispensing processes of multiple pipetting units based on the available data. However, it is also possible for the magnetic field sensor data to be evaluated within the integrated motor cassette.In this case, it is possible that there is no sensor data connection or that there is a reduced data connection through which only the position of the piston is communicated to the control unit.

[0023] According to the invention, the integrated motor cassette further comprises a storage element. This storage element can be used in a variety of ways, e.g., for storing sensor data or calibration data, as described in detail below.

[0024] According to the invention, the storage element is provided with calibration data, wherein the calibration data describes a correlation between measured values ​​of the magnetic field sensors and the position of the piston. The calibration data can be such that the position of the piston in the guide tube can be determined very precisely by combining the measured values ​​of the magnetic field sensors and the calibration data. With the calibration data available, the electric motor, consisting of the piston and coil assembly, can be operated precisely without requiring the piston to be moved to a reference position or a similar initialization routine. The electric motor of the integrated motor cassette is ready for immediate use after the integrated motor cassette is connected to the pipetting system. The calibration data can be the result of a calibration process performed during the manufacture of the integrated motor cassette, i.e.,The result of a calibration process performed before connecting the integrated motor cassette to the pipetting system is therefore the integrated motor cassette, which is an easily replaceable and immediately usable complete unit that does not require any additional adjustment or calibration when connected to the pipetting system. The correlation between the magnetic field sensor readings and the piston position can be presented in the form of a lookup table, a formulaic description, or any other suitable format.

[0025] According to a further embodiment, the calibration data also includes a description of the influence of the current flow in the coil assembly on the measured values ​​of the magnetic field sensors. This description of the influence of the current flow in the coil assembly can be provided as a lookup table, as a formulaic description, or in any other suitable format. Based on this description, the influence of the magnetic field of the coil assembly on the measured values ​​of the magnetic field sensors can be factored out. In this way, the position of the piston in the guide tube can be determined from the measured values ​​of the magnetic field sensors in a particularly reliable manner. In particular, a control unit that regulates the current flow to the coils of the coil assembly can directly remove the influence of this current flow on the magnetic field from the measured values.

[0026] According to another embodiment, the calibration data can be read from a control unit of the pipetting system. In particular, the calibration data can be read via the sensor data port described above. Thus, only one data port is required for transmitting the measured values ​​from most magnetic field sensors and the calibration data, which is advantageous in terms of space requirements and the complexity of the integrated motor cassette. However, it is also possible for the calibration data to be read via a separate calibration data port.

[0027] According to another embodiment, the coil arrangement comprises a plurality of coils arranged in a circle around the guide tube. This direct arrangement around the guide tube allows the piston to be moved within the guide tube with high efficiency.

[0028] According to a further embodiment, the housing is made of a soft magnetic material, in particular a soft magnetic nickel-iron alloy. A soft magnetic material, in particular a soft magnetic nickel-iron alloy, is particularly suitable as magnetic shielding and for providing magnetic feedback through the housing.

[0029] According to another embodiment, the size of the housing is matched to the grid of the pipetting system, in particular to a standardized grid dimension. Thus, the integrated motor cassette can be conveniently used in all pipetting systems that operate with a multitude of pipetting units in a predetermined grid, especially a standardized grid. In particular, in a pipetting system with multiple pressure tubes arranged in a grid, multiple integrated motor cassettes can be positioned side by side. Individual integrated motor cassettes can be replaced as needed, and maintenance is further simplified by the fact that the surrounding integrated motor cassettes are insensitive to the maintenance process due to their respective housings.

[0030] According to another embodiment, the housing has a substantially rectangular cross-section. This substantially rectangular cross-section allows the integrated motor cartridge to be conveniently inserted into a grid of the pipetting system. The feature that the housing has a substantially rectangular cross-section does not mean that such a cross-section must be present along the entire length of the integrated motor cartridge. Rather, the feature states that the cross-section is substantially rectangular at least along a large portion of the principal extension direction of the integrated motor cartridge, for example, at least along 80% of the length of the integrated motor cartridge. The principal extension direction of the integrated motor cartridge corresponds to the extension direction of the guide tube.

[0031] According to another embodiment, the housing has a cross-sectional area between 50 mm² and 200 mm², in particular between 100 mm² and 150 mm², and further in particular between 130 mm² and 140 mm².

[0032] According to another embodiment, the longer side of the substantially rectangular cross-section has a length between 12 mm and 20 mm, in particular between 14 mm and 18 mm, and further in particular between 15 mm and 16 mm.

[0033] According to a further embodiment, the shorter side of the substantially rectangular cross-section has a length of less than 9 mm, in particular a length between 7 mm and 9 mm, and more specifically between 8 mm and 9 mm. With a maximum length of less than 9 mm for the shorter side of the substantially rectangular cross-section, the integrated motor cassette can be conveniently inserted into standard grid dimensions.

[0034] According to another embodiment, the piston has a seal against the guide tube on the side facing the pressure tube. It is also possible for the piston to have a further seal against the guide tube on the side facing away from the pressure tube. In this way, two seals are provided between the piston and the guide tube, and symmetrical piston movement towards and away from the pressure tube can be ensured.

[0035] According to another embodiment, the piston's entire travel path is within the housing. In this way, the piston is mechanically protected from external influences by the housing in any position. Furthermore, this minimizes the detent torques exerted by the piston on the guide tube and other components.

[0036] According to another embodiment, a stop for the piston, an air filter, or an integrated stop-air filter unit is provided on the side of the guide tube facing away from the pressure tube. The stop effectively limits the piston's movement, defining the end of the used portion of the guide tube. This ensures that the piston cannot interact unintentionally with other components within the housing. The air filter effectively keeps the guide tube free from external influences, such as dust, thus reliably guaranteeing precise and sealed piston movement over extended periods.

[0037] According to another embodiment, the integrated motor cassette further comprises a temperature sensor arranged within the housing for measuring the temperature within the integrated motor cassette. The integrated motor cassette can also have a data connection for transmitting temperature measurements. This can be a separate data connection. However, it is also possible that the sensor data connection described above, intended for magnetic field data, is also used for transmitting the temperature measurements. The temperature sensor can detect whether the electric motor within the integrated motor cassette is overloaded. Based on this information, the current flow through the coils of the coil assembly can be terminated before the electric motor of the integrated motor cassette is damaged.Especially in the closed system of the integrated motor cassette, the ability to observe the temperature is particularly valuable because the components are shielded from the outside world by the housing and cannot be inspected.

[0038] According to a further embodiment, the integrated motor cassette also features a cooling duct arranged inside the housing along the guide tube. This duct has a first opening through the housing on the side facing the pressure tube and a second opening through the housing on the side facing away from the pressure tube. This allows the interior of the housing to be effectively cooled by a flow of cooling air within the cooling duct. Since the integrated motor cassette will typically be arranged vertically in a pipetting system, the cooling duct creates a chimney effect from the side of the housing facing the pressure tube to the side facing away from the pressure tube, resulting in effective cooling of the interior of the housing.

[0039] According to a further embodiment of the invention, the integrated motor cassette also has a holder on the side of the housing facing away from the pressure tube, with which the integrated motor cassette can be fixed relative to the pipetting system. In this way, the integrated motor cassette can be securely fixed in position relative to the rest of the pipetting system on the side facing away from the pressure tube. Together with the positional fixation of the integrated motor cassette via the pressure tube connection described above, this results in positional fixation of the integrated motor cassette at both ends, thus ensuring a particularly reliable and precise positioning of the integrated motor cassette within the pipetting system.

[0040] According to a further embodiment, the holder has a contact surface that can be brought into engagement with a complementary contact surface of the pipetting system for aligning the integrated motor cassette. The contact surface engaging with a complementary contact surface enables very precise alignment of the integrated motor cassette via the two contact surfaces.

[0041] According to another embodiment, the holder has a guide element that can be inserted into a recess of the pipetting system to align the integrated motor cartridge. While the guide element can rest against the pipetting system, it is also possible for it to be inserted into the recess without contacting a mating surface. In other words, the guide element can be positioned with some play in the recess. This simplifies the insertion of the integrated motor cartridge compared to the case described above with complementary contact surfaces, while still providing a degree of positional fixation.

[0042] According to a further embodiment, the holder has a receptacle, in particular a hole or threaded hole, for inserting a locking element provided on the pipetting system, in particular a locking pin or a locking screw. The interaction of a locking element of the pipetting system and a corresponding receptacle in the holder of the integrated motor cassette allows for particularly secure positioning of the integrated motor cassette within the pipetting system.

[0043] Exemplary embodiments of the invention further comprise a pipetting system for aspirating and dispensing pipetting fluid, comprising at least one pressure tube, wherein each of the at least one pressure tube has a coupling device for connecting a pipetting tip to the respective pressure tube; and, for each of the at least one pressure tube, a motor cassette connection for connecting the pipetting system to one integrated motor cassette according to one of the embodiments described above. The pipetting system comprises at least one integrated motor cassette according to one of the embodiments described above. The modifications, additional features, and effects described above with reference to the integrated motor cassette are applicable analogously to the pipetting system for aspirating and dispensing pipetting fluid.The integrated motor cassette can be inserted into and removed from the pipetting system as a single unit. Once inserted into the pipetting system, the integrated motor cassette becomes part of the system.

[0044] According to another embodiment, the pipetting system has a plurality of pressure tubes. In particular, the pipetting system can have a plurality of pressure tubes arranged in a grid, e.g., 96 pressure tubes. It is possible that each pressure tube of the pipetting system has a motor cassette connection for connecting the pipetting system to a respective integrated motor cassette. However, it is also possible, and encompassed by the invention, that motor cassette connections for connecting the pipetting system to an integrated motor cassette are provided for some of the pressure tubes, while another part of the pressure tubes is connected to other types of electric motors.

[0045] According to a further embodiment, the motor cassette connection has a pipetting system-side pressure tube connection that can be gas-tightly connected to the pressure tube connection of the integrated motor cassette. In a further embodiment, the pipetting system-side pressure tube connection includes a free end of the pressure tube that can be inserted into a corresponding receptacle of the pressure tube connection of the integrated motor cassette. The free end of the pressure tube can, for example, be a free end of the pressure tube that protrudes from the housing of the pipetting system. In particular, the free end can protrude on the inside of the housing of the pipetting system. This allows the integrated motor cassette to be placed onto the free end of the pressure tube inside the pipetting system. The free end of the pressure tube can have an O-ring arranged around the pressure tube.

[0046] According to a further embodiment, the pipetting system has a locking element for each of the at least one pressure tube, in particular a locking pin or a locking screw, with which the integrated motor cassette can be fixed relative to the pipetting system. The locking element can be inserted or screwed into a corresponding receptacle in a holder of the integrated motor cassette, in particular a hole or a threaded hole. It is also possible for the locking element to engage with a guide element of the holder of the integrated motor cassette, thus securing it in position. For example, a locking screw can be positioned with its end against a guide element of the holder of the integrated motor cassette, so that the guide element is fixed.

[0047] According to another embodiment, the pipetting system has a control unit which is configured to control an integrated motor cassette for aspirating or dispensing pipetting fluid.

[0048] According to a further embodiment, the control unit can be coupled to the coil assembly of the integrated motor cassette and configured to control the movement of the piston. In particular, the control unit can be connected to the power terminal of the integrated motor cassette and supply the coils of the coil assembly with appropriate currents via the power terminal, thus controlling the movement of the piston. In this case, the current level through the coils is determined by the control unit outside the integrated motor cassette. It is also possible for the control unit to transmit control signals to the integrated motor cassette, and for the integrated motor cassette to be able to determine the current levels to the coils via the power terminal in accordance with the control signals.

[0049] According to a further embodiment, the control unit can be coupled to a plurality of magnetic field sensors of the integrated motor cassette and is configured to determine the position of the piston based on measured values ​​from the magnetic field sensors. In particular, the control unit can be connected to a sensor data port of the integrated motor cassette in order to receive the measured values ​​from the magnetic field sensors.

[0050] According to a further embodiment, the control unit can be coupled to a storage element of the integrated motor cassette and configured to read data, in particular calibration data, from the storage element. In this way, the control unit can access the data stored in the integrated motor cassette. Using the calibration data, the control unit can control the coils of the coil assembly of the integrated motor cassette in such a way as to enable highly precise movement of the piston.

[0051] Exemplary embodiments of the invention further comprise a method for replacing an integrated motor cassette of a pipetting system according to one of the embodiments described above, comprising the steps of: removing a first integrated motor cassette from the pipetting system, wherein the first integrated motor cassette is configured according to one of the embodiments described above and wherein the removal step comprises disconnecting the pressure tube connection of the first integrated motor cassette from a pipetting system-side pressure tube connection; and inserting a second integrated motor cassette into the pipetting system, wherein the second integrated motor cassette is configured according to one of the embodiments described above and wherein the insertion step comprises connecting the pressure tube connection of the second integrated motor cassette to the pipetting system-side pressure tube connection.

[0052] According to a further embodiment, the step of removing the first integrated motor cassette comprises at least one of the following steps: disconnecting the power connector of the first integrated motor cassette from a pipetting system-side power connector, disconnecting a sensor data connector of the first integrated motor cassette from a pipetting system-side sensor data connector, or disconnecting a retainer on the pressure tube-away side of the housing of the first integrated motor cassette from the pipetting system.Furthermore, the step of inserting the second integrated motor cassette may include at least one of the following: connecting the power connector of the second integrated motor cassette to the power connector on the pipetting system side, connecting a sensor data connector of the second integrated motor cassette to the sensor data connector on the pipetting system side, or connecting a bracket on the side of the housing of the second integrated motor cassette facing away from the pressure tube to the pipetting system.

[0053] Further exemplary embodiments of the invention are described below with reference to the figures. Fig. 1 shows an integrated motor cassette according to an exemplary embodiment of the invention in a perspective view; Fig. 2 The integrated motor cassette shows the Fig. 1 in a longitudinal section view; Fig. 3 The integrated motor cassette shows the Fig. 1 in a cross-sectional view; Fig. 4 shows a pipetting system according to an exemplary embodiment of the invention, in which the integrated motor cassette of the Fig. 1 is used; Fig. 5 shows a section of the pipetting system of the Fig. 4 in enlarged view; Fig. 6 shows selected components of the pipetting system of the Fig. 4 as a block diagram; and Fig. 7 shows an integrated motor cassette according to a further exemplary embodiment of the invention in a longitudinal section view.

[0054] Fig. 1 Figure 1 shows an integrated motor cassette 2 according to an exemplary embodiment of the invention in a perspective view from the outside. The integrated motor cassette 2 has a housing 4. The housing 4 is essentially cuboid. The housing 4 has a main extension direction, which is shown in the perspective view from Fig. 1 The housing 4 runs from the lower left to the upper right. It has an end region 40 facing the pressure pipe and an end region 42 facing away from the pressure pipe. The main extension direction of the housing 4 runs from the end region 40 facing the pressure pipe to the end region 42 facing away from the pressure pipe. In the cross-sections perpendicular to the main extension direction, the housing 4 has a substantially rectangular cross-section.

[0055] In the end region 40 facing the pressure tube, the integrated motor cassette 2 has a pressure tube connection 6. The pressure tube connection 6 has a cylindrical receptacle into which a pressure tube of a pipetting system can be inserted, as described in detail below. In the end region 42 facing away from the pressure tube, the integrated motor cassette 2 has a guide element 12. The guide element 12 is an extension of the housing 2 along its main direction of extension, but has a much smaller cross-section than the housing 4. By means of the guide element 12, the integrated motor cassette 2 can be fixed in position within a pipetting system, as described in detail below.

[0056] The integrated motor cassette 2 also has a power connection 8. The power connection 8 is a connection board that supplies power to the coils located in the housing 4 and protrudes from the housing 4, as shown in Fig. 1 shown. The connection board 8 can be connected to an external power source. Furthermore, the integrated motor cassette 2 has a sensor data connection 10. The sensor data connection 10 is connected inside the housing 4 to a plurality of magnetic field sensors and protrudes from the housing 4, as shown in Fig. 1 shown to transmit the measured values ​​of the magnetic field sensors to a control unit located outside the housing 4.

[0057] Fig. 2 shows a longitudinal section through the integrated motor cassette 2 of the Fig. 1 In particular, it shows Fig. 2 a longitudinal section through the integrated motor cassette 2 along a longitudinal section plane parallel to the one in Fig. 1 The upper level of the integrated motor cassette 2 is shown. Fig. 2 Figure 4 shows the housing 4 with its components arranged therein, as well as the power connector 8 protruding from the housing 4 and the guide element 12 protruding from the housing 4.

[0058] A cylindrical guide tube 14 is arranged essentially centrally in the housing 4. The guide tube 14 terminates in the end region 40 facing the pressure tube at the pressure tube connection 6. In the exemplary embodiment of the Fig. 2 The guide tube 14 is integrally formed with the guide tube 14. In particular, one end region of the guide tube 14 forms the pressure tube connection 6. A stop air filter unit 30 is provided in the end region 42 facing away from the pressure tube. The stop air filter unit 30 prevents dust from entering the guide tube 14 and forms the end of the movement path of the piston described below, which is arranged in the guide tube 14. The central arrangement of the guide tube 14 in the housing 4 helps to ensure the most even possible load distribution on the piston seals described below.

[0059] A plurality of coils 20 are arranged around the guide tube, only one of which is provided with a corresponding reference numeral. In the exemplary embodiment of the Fig. 2 There are twenty coils (20) available.

[0060] The coils 20 are arranged in a circle around the guide tube 14. They are arranged adjacent to one another along the guide tube 14, e.g., pushed onto the guide tube 14. The majority of the coils 20 are connected to the power connection 8, which runs along the coils 20 from the end region 40 facing the pressure tube to the end region 42 facing away from the pressure tube, and also protrudes from the housing 4, as shown in Fig. 2 and also in Fig. 1 shown. The coils 20 are supplied with energy via the power connection 8.

[0061] In the exemplary embodiment of the Fig. 2 The power connector 8 is a connection board. Specifically, power connector 8 provides a conductor track for each of the coils 20 to supply them with power. It is also possible for several coils 20 to be supplied with power from a single conductor track on connection board 8. In particular, it is possible for three power phases to be provided via connection board 8, with each coil 20 receiving one of the three power phases.

[0062] A piston 16 is arranged in the guide tube 14. The piston 16 has a seal 24 on both its side facing the pressure tube and its side facing away from the pressure tube. The seals 24 separate the air volume between the piston 16 and the pressure tube connection 6 on the one hand, and between the piston 16 and the stop air filter unit 30 on the other. The piston 16 has six permanent magnets 18, each of the same length along the piston 16. The permanent magnets 18 are arranged in the piston 16 with their poles oriented in the same direction relative to each other. An example arrangement of the permanent magnets 18 would be SN-NS-SN-NS-SN-NS, where the hyphen denotes the boundary between the individual permanent magnets. Fig. 2 The boundaries between the permanent magnets 18 are marked by double lines. The piston 16 generates a magnetic field with alternating south and north poles through the permanent magnets 18; these poles are extremely sharply defined due to their arrangement with opposite poles to each other.

[0063] A plurality of magnetic field sensors 22 are arranged in the housing 4. These sensors are positioned along the guide tube 14, outside the plurality of coils 20, and along a wall of the housing 4. A total of twenty magnetic field sensors are arranged along the guide tube 14, with the reference numeral 22 appearing only once for clarity. In this example, the majority of the magnetic field sensors are Hall effect sensors. They measure the magnetic field present at the respective locations of the integrated motor cassette 2. The measured values ​​can be used to determine the position of the piston 16, as described below.

[0064] A cooling duct 26 is arranged in the housing 4 of the integrated motor cassette 2. The cooling duct 26 is arranged along a wall of the housing 24, on the side opposite the guide tube 14 compared to the majority of magnetic field sensors 22. The cooling duct 26 extends essentially from the end region 40 of the housing 4 facing the pressure tube to the end region 42 of the housing 4 facing away from the pressure tube. The cooling duct 26 has an opening through the housing 4 at both ends, allowing cooling air to flow through the cooling duct 26 from the outside.

[0065] The operation of the integrated motor cassette 2 is described below. The majority of coils 20 are energized via the power connection 8. By applying suitable currents to the majority of coils 20, time-varying magnetic fields are generated, which exert a mechanical force on the permanent magnets 18 of the piston 16 and move it within the guide tube 14. It is known to those skilled in the art how to configure the current flow through the majority of coils 20 to achieve the desired movement of the piston. Therefore, a more detailed description of the relationships between the movement of the piston 16 and the currents to be applied through the coils 20 can be omitted.

[0066] During operation, most magnetic field sensors measure the prevailing magnetic field at the respective points inside the housing. They transmit the measured values ​​via the above-mentioned [link / connection]. Fig. 1 The described sensor data connection 10 is connected to a control unit located outside the integrated motor cassette 2. This control unit is able to determine the position of the piston 16 from the measured values ​​of the magnetic field sensors 22. Based on this information and on the desired aspiration or dispensing process, the control unit supplies the majority of coils 20 with corresponding currents via the current connection 8, so that the desired movement of the piston 16 occurs. Thus, a control loop is established between the piston 16, the magnetic field sensors 22, the control unit, the current connection 8, and the coils 20, which enables highly precise positioning of the piston 16 within the guide tube 14.

[0067] Fig. 3 The integrated motor cassette 2 shows Fig. 1 and 2 in cross-section. The cross-sectional plane of the Fig. 3 is orthogonal to the longitudinal section plane 2 of the Fig. 2 In particular, the cross-sectional plane of the Fig. 3 along the axis labelled AA in Fig. 2 . Also the Fig. 3 The figure shows the guide tube 14, one of the coils 20 arranged around the guide tube 14, the power connection 8, one of the magnetic field sensors 22 and the cooling duct 26. Fig. 3 Figure 1 clearly shows that the cooling duct 26 is located next to the power connection 8. In this way, the cooling duct 26 is positioned close to the power connection 8 and also close to the coils 20, where most of the waste heat is generated.

[0068] In the cross-sectional plane of Fig. 3 A temperature sensor 28 and a memory element 36 are also arranged. The temperature sensor 28 measures the temperature inside the housing 4 of the integrated motor cassette 2. Calibration data for the integrated motor cassette 2 are stored on the memory element 36. The calibration data includes a description of the relationships between the measured values ​​of the magnetic field sensors 22 and the position of the piston 16. Furthermore, the calibration data includes a description of the magnetic field components detected by the magnetic field sensors 22 that are attributable to the current flow through the coils 20. Thus, a control unit can use the calibration data to subtract the magnetic field components caused by the coils 20 from the measured values ​​of the magnetic field sensors 22 and calculate the position of the piston 16 from the remaining magnetic field components.The calibration data can describe a variety of artifacts in the measurement of the magnetic fields, such as offset effects of the magnetic field sensors, positional inaccuracies compared to the nominal position of the magnetic field sensors 22, and positional inaccuracies compared to the nominal position of the permanent magnets 18. The calibration data can be determined for the given, specific integrated motor cassette 2 during its production.

[0069] The magnetic field sensors 22, the temperature sensor 28, and the memory element 36 are connected to the sensor data port 10. The measured values ​​of the magnetic field sensors 22 and the temperature sensor 28, as well as the calibration data stored in the memory element 36, are read by a control unit located outside the integrated motor cassette 4. Based on the measured data from the magnetic field sensors 22 and the calibration data, the control unit is designed to regulate the currents through the coils 20 and thus move the piston 26 as desired.

[0070] Fig. 4 The integrated motor cassette 2 shows Fig. 1 bis 3 , inserted into a pipetting system 100 according to an exemplary embodiment of the invention. By connecting to and using the pipetting system 100, the integrated motor cassette 2 becomes part of the pipetting system 100. Fig. 4 shows the integrated motor cassette 2 in the same longitudinal section plane as Fig. 2 Therefore, the pipetting system is also shown in this longitudinal section plane.

[0071] The pipetting system 100 has a housing 102 in which the integrated motor cassette 2 is arranged. Furthermore, the pipetting system 100 has a pressure tube 104 and a pipetting tip 106. The pressure tube 104 extends from inside the housing 102, specifically from the integrated motor cassette 2, to outside the housing 102. The pressure tube 104 is fixedly connected to the housing 102 of the pipetting system. At one end, the pressure tube 104 is connected to the pressure tube port 6 of the integrated motor cassette, as shown below with reference to the enlarged detail view of the Fig. 5 The pressure tube 104 is connected to the pipetting tip 106 at its other end. The pipetting tip 106 is detachably connected to the pressure tube 104. In particular, the pipetting tip 106 can be easily replaced, e.g., if, due to possible contamination of the pipetting tip with a first pipetting liquid, the unadulterated pipetting of a second pipetting liquid cannot be guaranteed.

[0072] The aspiration or dispensing of a pipetting liquid through the pipetting tip 106 is achieved by the build-up or release of gas pressure in the compressed air volume formed by the guide tube 14 of the integrated motor cassette 2, the pressure tube 104, and the pipetting tip 106. The build-up or release of the gas pressure is effected by the movement of the piston 16 in the guide tube 14.

[0073] In the exemplary embodiment of the Fig. 4 The integrated motor cassette 2 is mechanically connected to the pipetting system 100 as follows. The pressure tube connection 6 of the integrated motor cassette 2, i.e., in this example, the end region of the guide tube 14 of the integrated motor cassette 2, is mounted on a freestanding end region of the pressure tube 104. This is described below with reference to Fig. 5 The guide element 12 is described in more detail below. Furthermore, the guide element 12 is arranged in a receptacle 108. The receptacle 108 is larger than the guide element 12. The guide element 12 does not rest against the surfaces of the receptacle 108. However, the guide element 12 is arranged within the defined area of ​​the receptacle 108.

[0074] The pipetting system 100 has a locking screw 110, which is arranged in a screw thread 112 of the pipetting system 100. In particular, the locking screw 110 is screwed through the screw thread 112 so that its end engages with the guide element 12. Through the engagement of the locking screw 110 with the guide element 12 and the frictional engagement of the locking screw 110 in the screw thread 112, the end region of the integrated motor cassette 2 facing away from the pressure tube is fixed in position within the pipetting system 100.

[0075] Fig. 5 shows the connection between the integrated motor cassette 2 and the pressure pipe 104 in greater detail. In particular, Fig. 5 an enlarged view of the in Fig. 4 connection shown. The one in Fig. 5 The area shown corresponds to the one in Fig. 4 circled area B.

[0076] The pressure tube 104 has a free end 114 facing the integrated motor cassette 2. An O-ring 116 is fitted around the free end 114. The pressure tube connection 6 is pushed onto the free end 114. This push-fit connection secures the position of the integrated motor cassette 2 relative to the housing 102 of the pipetting system 100. Furthermore, the O-ring 116 creates a gas-tight connection between the free end 114 of the pressure tube 104 and the pressure tube connection 6. Thus, when the integrated motor cassette 2 is connected to the pressure tube 104, a sealed volume is formed, with the exception of the opening in the pipetting tip, consisting of a portion of the guide tube 14, the pressure tube 104, and the pipetting tip 106.

[0077] In addition to the one relating to Fig. 4 and 5In addition to the mechanical connection between the integrated motor cassette 2 and the pipetting system 100 described above, the integrated motor cassette 2 is also connected to the pipetting system 100 via the power connector 8 and the sensor data connector 10. While the power connector 8 is in Fig. 4 As shown, the sensor data connection 10 is located outside the cross-sectional plane of Fig. 4 and 5 .

[0078] Fig. 6 The block diagram shows the connections between the integrated motor cassette 2 and the pipetting system 100 for controlling the electric motor of the integrated motor cassette 2. Fig. 6 is an abstract representation of the pipetting system of Fig. 4 and 5Based on a portion of its functional components. The components located within the integrated motor cassette 2 are shown within a dashed frame, while the components located outside the integrated motor cassette 2 are shown outside the dashed frame. All components belong to the Pipetting System 100.

[0079] The integrated motor cassette 2 is connected to a control unit 120 of the pipetting system 100 via the power connection 8 and the sensor data connection 10. The control unit 120 is also connected to a power supply 130. Based on a desired movement of the piston 16, the control unit 120 determines the currents to be applied to the coils 20. The control unit 120 draws energy from the power supply 130 and conditions the energy received from the power supply 130 such that the currents required for the desired movement of the piston 16 are applied to the coils 20 via the power connection 8.

[0080] The control unit 120 is connected via the sensor data port 10 to the majority of magnetic field sensors 22 and to the storage element 36. The storage element 36 contains calibration data relating to the position measurement of the piston 16. This calibration data is read by the control unit 120 and used to determine the position of the piston 16. The magnetic field sensors 22 measure the magnetic field currently present at their positions. The measured values ​​thus represent a spatial distribution of the instantaneous magnetic field. This magnetic field consists of two main components: one generated by the current through the sputen 20 and one generated by the permanent magnets of the piston 16. Using the calibration data, the control unit 120 removes the first component of the magnetic field from the measured values, at least to a substantial extent.Furthermore, the control unit 120 calculates the position of the piston 16 from the second component using the calibration data. The second component has a strong periodic component due to the alternating orientation of the permanent magnets in the piston 16. The calibration data includes a description of offset effects of the magnetic field sensors 22, deviations of the positions of the magnetic field sensors 22 from a uniform distribution along the guide tube, and deviations of the arrangement of the permanent magnets and their poles from a uniform distribution. Using the calibration data, the control unit 120 adjusts the measured values ​​of the magnetic field sensors 22 and determines the position of the piston 16 with high precision. The control unit 120 thus receives feedback regarding the position of the piston 16 and can therefore move it very precisely within the guide tube.

[0081] Fig. 7 Figure 1 shows an integrated motor cassette 2 according to a further embodiment of the invention in a longitudinal sectional view. The integrated motor cassette 2 of the Fig. 7 is very similar to the integrated motor cassette 2 of the Fig. 1 bis 3 Furthermore, the longitudinal section plane corresponds to the Fig. 7 the longitudinal plane of the Fig. 2 . For those features of the integrated motor cassette 2 of the Fig. 7 , which are not described in detail below, refer to the description of the Fig. 1 bis 3 , in particular the Fig. 2 , referred to above.

[0082] The integrated motor cassette 2 of the Fig. 7 It has no guide element 12, but instead features a different type of support in the pressure tube-applied end region 42 of the housing 4 for positional fixation relative to a pipetting system. The integrated motor cassette 2 of the Fig. 7has a bracket 32 ​​which has a threaded hole 34. A locking screw of a pipetting system can be screwed into the threaded hole 34 and thus fix the integrated motor cassette 2 to the pipetting system in the end region 42 of the housing 4 facing away from the pressure tube.

[0083] The integrated motor cassettes of the exemplary embodiments described above allow the electric motor of a pipetting system to be replaced as a complete unit, thus reducing maintenance requirements. These integrated motor cassettes are particularly advantageous for relatively new pipetting systems that move the piston back and forth at very high speeds during a pipetting process. In these systems, the piston stroke is many times greater than the volume of the aspirated or dispensed liquid, and the aspiration or dispensing of the liquid occurs via a highly dynamic pressure wave. In such a dynamically driven system, wear on the electric motor components can be significant and negatively impact the performance of the pipetting system. Therefore, maintenance is of paramount importance in such systems.Such a high-dynamics pipetting system is disclosed in WO 2017 / 0107084 A1. The content of the aforementioned application is fully incorporated into the present patent application by reference. In particular, the pipetting system of the present patent application can be further developed with all features of the claims of WO 2017 / 0107084 A1, individually or in any combination.

[0084] Although the invention has been described with reference to exemplary embodiments, it is apparent to a person skilled in the art that various modifications can be made and equivalents used without departing from the scope of the invention. The invention is not intended to be limited by the specific embodiments described. Rather, it encompasses all embodiments covered by the appended claims.

Claims

1. An integrated motor cartridge (2) for connection to and for use in a pipetting system, comprising: a housing (4), a guide tube (14), a piston (16) provided with a plurality of permanent magnets (18), the piston having a pressure tube facing side and a pressure tube distal side, wherein the piston is arranged in the guide tube and wherein the piston has at least one seal (24) with respect to the guide tube, and a coil assembly (20) by means of which the piston can be moved in the guide tube when current is supplied to the coil assembly, wherein the guide tube, the piston and the coil assembly are arranged in the housing, wherein the integrated motor cartridge (2) further comprises a plurality of magnetic field sensors (22) arranged within the housing (4) along the guide tube (14) for determining the position of the piston (16), wherein the integrated motor cartridge (2) further comprises a memory element (36), the memory element containing calibration data, the calibration data describing a correlation between measured values of the magnetic field sensors (22) and the position of the piston (16), and wherein the integrated motor cartridge further comprises: a pressure tube connection (6) by means of which the guide tube, on the pressure tube facing side o fthe piston, can be connected in a gastight manner to a pressure tube of the pipetting system, and a power connection (8) which is coupled to the coil assembly and adapted to be coupled to a power supply arranged outside of the integrated motor cartridge, wherein the integrated motor cartridge can be introduced into and removed from the pipetting system as a unit.

2. The integrated motor cartridge (2) according to claim 1, wherein the pressure tube connection (6) is designed to fix the position of the integrated motor cartridge with respect to the pipetting system; and / or wherein the pressure tube connection (6) has a receptacle for a motor facing side of the pressure tube, wherein the receptacle in particular has a contact surface for an O-ring arranged around the pressure tube.

3. The integrated motor cartridge (2) according to claim 1 or 2, wherein the power connection (8) is designed as a printed circuit, wherein the printed circuit is disposed within the housing (4) along the guide tube (14) and / or extends through the housing (4) in a pressure tube distal end portion (42) of the integrated motor cartridge.

4. The integrated motor cartridge (2) according to any of the preceding claims, further comprising: a sensor data connection (10) coupled to the plurality of magnetic field sensors (22) and adapted to be coupled to a control unit of the pipetting system arranged outside of the integrated motor cartridge.

5. The integrated motor cartridge (2) according to any of the preceding claims, wherein the calibration data further include a description of the influence of the current flow of the coil assembly (20) on the measured values of the magnetic field sensors (22).

6. The integrated motor cartridge (2) according to any of the preceding claims, wherein the calibration data are adapted to be read out by a control unit of the pipetting system.

7. The integrated motor cartridge (2) according to any of the preceding claims, wherein the size of the housing (4) is adapted to the grid of the pipetting system, in particular to a standardized grid pattern; and / or wherein the housing (4) has a substantially rectangular cross section and / or wherein the housing (4), in cross section, has an area between 50 mm2 and 200 mm2, in particular between 100 mm2 and 150 mm2, still more in particular between 130 mm2 and 140 mm2.

8. The integrated motor cartridge (2) according to any of the preceding claims, further comprising a cooling duct (26) arranged within the housing (4) along the guide tube (14) and having a first opening through the housing on the pressure tube facing side of the housing and a second opening through the housing on the pressure tube distal side of the housing.

9. The integrated motor cartridge (2) according to any of the preceding claims, further comprising a support (32) on the pressure tube distal side of the housing (4), with which the integrated motor cartridge can be fixed with respect to the pipetting system, wherein the support in particular has a contact surface adapted to be engaged with a complementary contact surface of the pipetting system for alignment of the integrated motor cartridge and / or wherein the support in particular has a guide member (12) adapted to be introduced in a recess of the pipetting system for alignment of the integrated motor cartridge.

10. A pipetting system (100) for aspirating and dispensing pipetting liquid, comprising: at least one pressure tube (104), each of the at least one pressure tube having a coupling device for coupling a pipetting tip (106) to the respective pressure tube, for each of the at least one pressure tube, a motor cartridge connection for connecting the pipetting system to a respective integrated motor cartridge (2) according to any of the preceding claims, and at least one integrated motor cartridge according to any of the preceding claims, inserted into the pipetting system.

11. The pipetting system (100) according to claim 10, wherein the motor cartridge connection comprises: a pressure tube connection (114) on the side of the pipetting system, which can be connected to the pressure tube connection (6) of the integrated motor cartridge (2) in a gastight manner, wherein the pressure tube connection (114) on the side of the pipetting system in particular comprises a free end of the pressure tube (104) which is adapted to be inserted into a corresponding receptacle of the pressure tube connection (6) of the integrated motor cartridge (2).

12. The pipetting system (100) according to claim 11, further comprising a control unit (120) configured to control an integrated motor cartridge (2) for aspirating and dispensing pipetting liquid.

13. The pipetting system (100) according to claim 12, wherein the control unit (120) is adapted to be coupled to the coil assembly (20) of the integrated motor cartridge (2) and configured to control a motion of the piston (16); and / or wherein the control unit (120) is adapted to be coupled to the plurality of magnetic field sensors (22) of the integrated motor cartridge (2) and is configured to determine the position of the piston (16) on the basis of measured values of the magnetic field sensors; and / or wherein the control unit (120) is adapted to be coupled to the memory element (30) of the integrated motor cartridge (2) and configured to read out calibration data from the data memory.

14. A method of replacing an integrated motor cartridge (2) of a pipetting system (100) according to any of claims 11 to 13, comprising the steps of: removing a first integrated motor cartridge (2) from the pipetting system (100), wherein the first integrated motor cartridge (2) is in accordance with any of claims 1 to 9 and wherein the step of removing comprises releasing the pressure tube connection (6) of the first integrated motor cartridge (2) from a pressure tube connection (114) on the side of the pipetting system, and inserting a second integrated motor cartridge (2) into the pipetting system (100), wherein the second integrated motor cartridge (2) is in accordance with any of claims 1 to 9 and wherein the step of inserting comprises connecting the pressure tube connection (6) of the second integrated motor cartridge (2) to the pressure tube connection (114) on the side of the pipetting system.

15. The method according to claim 14, wherein the step of removing the first integrated motor cartridge (2) comprises at least one of the following steps: releasing the power connection (8) of the first integrated motor cartridge (2) from a power connection on the side of the pipetting system, releasing a sensor data connection (10) of the first integrated motor cartridge (2) from a sensor data connection on the side of the pipetting system, releasing a support on the pressure tube distal side of the housing (4) of the first integrated motor cartridge (2) from the pipetting system (100); and wherein the step of inserting the second integrated motor cartridge (2) comprises at least one of the following steps: connecting the power connection (8) of the second integrated motor cartridge (2) to the power connection on the side of the pipetting system, connecting a sensor data connection (10) of the second integrated motor cartridge (2) to the sensor data connection on the side of the pipetting system, connecting a support on the pressure tube distal side of the housing (4) of the second integrated motor cartridge (2) to the pipetting system (100).