Lubricant dispenser for use in an environment at risk of explosion

Abstract

The invention relates to a lubricant dispenser (1) for use in an environment at risk of explosion, comprising at least a lubricant reservoir (2), an electromechanical drive (7) which acts on at least one actuating element (4) for dispensing lubricant from the lubricant reservoir (2), a control electronics system (9) for the drive (7), and a battery unit (8) which is replaceably connected or connectable to the control electronics system (9) and has a protective housing (10) and one or more batteries (11) arranged in the protective housing (10), the battery poles (+, -) of the batteries being contact-connected or contact-connectable to the control electronics system (9). A current-limiting protective device (12), which is connected in series between at least one battery pole (+, -) and a connection contact (13a, 13b) of the battery unit (8), is arranged in the protective housing (10).

Description

[0001] Lubricant dispenser for use in potentially explosive environments

[0002] Description:

[0003] The invention relates to a lubricant dispenser, in particular for use in potentially explosive environments, with at least

[0004] - a lubricant supply, e.g. a cartridge filled with lubricant,

[0005] - an electromechanical drive, e.g. an electric motor, which operates on at least one actuating element (e.g. a piston, a pump or the like) for dispensing / ejecting lubricant from the lubricant supply,

[0006] - control electronics for the drive and

[0007] - at least one replaceable battery unit which is connected or connectable to the control electronics and which has a (protective) housing and one or more batteries (i.e. battery cells) arranged in the (protective) housing, the (two) battery poles of which (or one or more connection contacts of the battery unit connected to one battery pole or both battery poles) are or can be contacted with the control electronics (e.g. with contact points / contact springs of the control electronics).

[0008] Such a lubricant dispenser is used, for example, for the automated lubrication of machine or system components, such as rolling bearings, plain bearings, linear guides, chains, or the like. The lubricant dispenser is connected, for example, to a lubrication point, e.g. a bearing, and can dispense lubricant, e.g. depending on the running time of a machine or at predetermined or variable intervals. Greases or oils, for example, are used as lubricants. The reservoir is also referred to as a cartridge, and such a cartridge can preferably be detachably and replaceably connected to an electromechanical drive or a housing of the lubricant dispenser to form a structural unit, e.g. by means of a screw connection, plug connection, snap connection, bayonet connection, or the like. The electromechanical drive is preferably an electric motor orThe electromechanical drive or drive unit comprises an electric motor. The electric motor is preferably a DC motor. The electromechanical drive, the control electronics, and the battery unit (or several battery units) are usually arranged in a (common) housing of the lubricant dispenser, with this housing being coupled, for example, to the lubricant reservoir. However, the battery unit(s) can also be coupled to the lubricant dispenser housing in a separate housing.

[0009] The electromechanical drive can, for example, operate on an actuating element designed as a piston, which is guided, for example, in the lubricant cartridge for pressing out the lubricant, whereby the piston is connected, for example, to a spindle that is driven by the electromechanical drive. The control electronics, which are arranged, for example, inside the housing of the lubricant dispenser, specifically control the electromechanical drive in order to eject lubricant, for example, at preselected dispensing intervals. Alternatively, the electromechanical drive can also operate on an actuating element designed as a pump or is part of a pump with which lubricant is sucked from the lubricant supply and dispensed via an outlet. A lubricant dispenser of the type described above with an electromechanical drive is marketed by the applicant, for example, under the product name "STAR VARIO". The simple and self-explanatory operation is carried out, for example,It features an LCD display with adjustment buttons, allowing adjustments to be made at any time. The electromechanical, reusable drive with battery pack ensures reliable, precise lubricant delivery, regardless of temperature and back pressure.

[0010] DE 10 2011 056 247 B4 describes a generic lubricant dispenser with an electromechanical drive that actuates a piston via a spindle, with control electronics on a control board being integrated into the housing of the lubricant dispenser.

[0011] Furthermore, from DE 10 2012 100 035 B4 a lubricant dispenser is known in which the lubricant cartridge is detachably connected to a carrier or housing which accommodates a battery-operated motor for driving the spindle, wherein in this embodiment too the spindle is connected to a piston for squeezing the lubricant out of the reservoir.

[0012] As an alternative to these embodiments, in which the drive operates via a spindle on a piston as the actuating element, the invention also encompasses embodiments in which an electromechanical drive drives a pump to convey a lubricant from a reservoir to an outlet. Such an embodiment is known, for example, from DE 10 2019 106 681 A1. The invention therefore always relates to a lubricant dispenser with an electromechanical drive, e.g. with an electric motor, wherein the electric motors are generally designed as DC motors that are operated via a battery unit with one or more batteries (i.e. battery cells). In the context of the invention, the term "battery" always means a "battery cell". This can be one or more primary cells or one or more rechargeable secondary cells, which are particularly advantageous from a sustainability perspective.Lubricator dispensers with electromechanical drives have proven to be extremely effective in practice, particularly because they enable reliable, precise, and variably adjustable lubricant dispensing. They can be used in a wide variety of environments.

[0013] Particular challenges arise when the lubricator is to be used in potentially explosive atmospheres where safety is of utmost importance, such as areas where flammable substances are manufactured, processed, transported, or stored. Potentially explosive atmospheres can occur, for example, in the chemical and petrochemical industries, as well as in oil and gas production and mining. Potentially explosive atmospheres are also common in the automotive industry, for example, in paint shops. Furthermore, this includes power plants and steel mills, as well as areas where coal or similar materials are transported, where conductive, explosive dust is present.

[0014] A lubricant dispenser specifically designed and suitable for use in such potentially explosive atmospheres is described, for example, in DE 10 2021 129 977 A1. The electronic circuitry integrated into the lubricant dispenser is divided into several circuit islands, with some or all of the circuit islands each being power-limited, so that the maximum possible power within each circuit island is limited to a specified maximum value.

[0015] Since high current and voltage values ​​are generally problematic in potentially explosive atmospheres, individual cells or battery units consisting of several individual cells are used for the drive in practice. Since the voltage of a cell decreases during operation, it must be replaced after a certain period of time. During the replacement process, voltage peaks can lead to the formation of small sparks, for example, if the cells come into contact with a spring element, such as a coil spring or a contact plate. Such sparks can trigger an explosion. For this reason, the batteries in lubricators designed for operation in potentially explosive atmospheres are usually changed outside the potentially explosive atmosphere.To do this, the lubricant dispenser is removed from the lubrication point and taken to a "non-Ex area" so that the device can be opened to change the battery cells in this safe environment. Alternatively, in certain cases, it is possible to wait to change the battery until an explosive gas-air atmosphere has dropped to a concentration that is no longer explosive. If, for example, the area is subject to a dust explosion hazard, the technician must wait until the coal dust, for example, has settled to the floor. Both replacing the battery in a non-Ex area and waiting for a safe atmosphere is time-consuming and therefore costly. Alternatively, a second lubricant dispenser of the same type is kept on hand in practice, so that the entire device, not the battery unit, is changed on-site in the hazardous area.However, this approach also entails additional costs, especially when maintenance personnel have to perform maintenance work at a large number of lubrication points. This is especially true when multiple devices often need to be replaced during a single inspection, and explosion-proof areas, such as those in refineries, can be large. Overall, replacing the battery unit in lubricant dispensers operated in potentially explosive atmospheres is complex. This is where the invention comes in.

[0016] The invention is based on the object of creating a lubricant dispenser of the type described above, which is particularly suitable for use in potentially explosive environments and enables simple and safe battery replacement.

[0017] To achieve this object, the invention teaches, in a generic lubricant dispenser of the type described above, that a protective device which limits the battery current is arranged in the protective housing of the battery unit and is connected in series between at least one battery pole and a connection contact of the battery unit.

[0018] The invention is based on the realization that the problems occurring in the prior art can be avoided and the effort required to replace the batteries can be significantly reduced if the battery unit itself is designed in such a way that sparking is reliably avoided even when the battery unit is replaced. This is achieved according to the invention by limiting the battery current of the battery unit to a level or current intensity at which sparking is avoided or a potential contact spark does not have sufficient energy to develop into an effective ignition spark. For this purpose, a protective device that limits the battery current is integrated into the protective housing of the battery unit. Such a protective device can, for example,be designed as an electronic protection board which is provided with a current limiter, wherein a connection contact is arranged on the protection board or connected to the protection board, so that one of the battery poles is connected to the connection contact with the current limiter interposed, and consequently the protection device is connected in series between one of the battery poles and the corresponding connection contact (of the battery unit). At least one of the battery poles is therefore not connected directly to the control electronics or to the contact element of the control electronics, but via a current limiter. The battery unit comprises at least one battery and consequently a battery cell which has two battery poles, namely a positive pole and a negative pole, wherein e.g.one of the poles directly forms a connection contact for contacting the control electronics, and the other pole is connected to the connection contact via the interposition of the protective device. However, several batteries and consequently battery cells can also be connected in series or, alternatively, in parallel within the battery unit, whereby two poles of the batteries or battery unit, namely a positive pole and a negative pole, are always contacted (directly or indirectly) with the control electronics. At least one of the battery poles, however, is not contacted directly with the control electronics, but via the described current-limiting protective device, so that the battery current is always limited and the formation of an ignition spark is avoided.This allows the battery unit according to the invention, also referred to as a battery set or battery pack, to be replaced even within a potentially explosive environment without the risk of explosion. The effort required to replace the battery is significantly reduced because the lubricant dispenser does not have to be removed from the potentially explosive area, nor does it require a complete replacement of the lubricant dispenser within the potentially explosive area. Of particular importance according to the invention is the limitation of the battery current by the protective device integrated into the protective housing of the battery unit, which can be, for example, a protective circuit board.

[0019] There are various technical options for the electrical or electronic design of the protective device and consequently for the assembly of a protective circuit board.

[0020] For example, the protective device can include a resistor to limit the current, which is connected in series between the battery terminal and the battery pack's terminal contact, for example. The terminal contact can also be located on the protective circuit board, for example. If a single resistor is used, it must be selected with a sufficiently large design / size to absorb and dissipate the heat generated by a correspondingly high current flow, without the heating of the resistor creating a risk of explosion.

[0021] As an alternative to a single, appropriately dimensioned resistor, several smaller resistors can be used, for example, connected in series. Alternatively, several resistors can be connected in parallel, or a combination of resistors connected in series and parallel can be used. Apart from the appropriate dimensioning of the resistance values, the use of several resistors, each with a smaller design, makes it possible to distribute the resulting heat across several resistors, so that the overall dimensions of the resistors are smaller relative to their size. Alternatively or additionally, the protective device can be equipped with a fuse, e.g. a melting fuse. This is preferably combined with one or more resistors. It is then possible to use one or more resistors in an even smaller size.If the current is too high, the fuse will blow or the fuse will blow and interrupt the power supply.

[0022] In a further, alternative embodiment, the protective device can have an electronic protective circuit that has at least one current monitor. Such current monitoring can be implemented, for example, via a current measuring resistor (shunt). If a certain voltage drops across this resistor, a voltage monitoring module detects that the voltage has been exceeded and activates an electronic element, e.g. a thyristor, which triggers a short circuit without any possibility of deactivation. This triggers a fuse. The maximum current that can flow in the event of a short circuit is limited by one or more resistors. In order to ensure fail-safe operation when using (such) an electronic circuit, the circuit is preferably implemented with multiple redundancy in the protective device, e.g. triple redundancy. This is particularly useful when a particularly high level of explosion protection is required, e.g.for Zone Zero.

[0023] The protective device according to the invention always limits the battery current so that sparking is reliably avoided.

[0024] According to the invention, the batteries and consequently battery cells and the protective device are arranged within the protective housing described above. It is always expedient to design the battery unit in such a way that the protective measures taken cannot be deactivated. The protective device, e.g., the protective circuit board, is therefore particularly preferably arranged in the protective housing in such a non-detachable manner that the protective circuit board cannot be removed from the battery unit without destroying it (the battery unit). If a user therefore attempts to remove the protective mechanism, this will simultaneously destroy or damage the battery unit, to the extent that the battery unit can no longer be used properly. Mechanical protection therefore prevents a user from removing the protective device, e.g., the populated circuit board, without destroying the battery set.

[0025] This can be achieved, for example, by designing the protective housing in such a way that it cannot be opened non-destructively. The protective housing can consist of several housing parts, e.g., two housing halves that can be connected to one another or a main housing part that is closed with a housing cover. In any case, the individual housing parts are permanently connected to one another during assembly, so that the housing parts cannot be separated to remove the protective electronics and, consequently, the housing cannot be opened non-destructively. This can be achieved, for example, by welding the housing parts together, e.g., by ultrasonic welding, friction welding, mirror welding, etc. Alternatively, the housing parts can be glued, cast, or hot-stitched.Furthermore, it is possible to connect the housing parts to one another in a form-fitting manner, namely by means of a non-destructively removable connection. This can be achieved, for example, by clipping, crimping, or similar methods. To meet the special requirements and, in particular, standards for operation in potentially explosive atmospheres, the battery unit is preferably designed so that, even if dropped from a height of 1 m, the protective housing is not damaged to such an extent that the current-limiting device or the protective device can be removed from the protective housing.

[0026] A supplementary or alternative option is to surround the protective device or parts of it with a potting compound, thus encapsulating it. This can serve both to secure the protective device within the housing and to protect the components themselves or even the individual battery cells. The potting compound can also improve heat dissipation.

[0027] Especially when a solution with a fuse is used, encapsulation is particularly advantageous, or may even be necessary, to absorb the heat generated when the fuse blows. The encapsulation compound around or above the fuse therefore serves to distribute the temperature over a larger surface area, preventing the protective circuit board from becoming excessively hot.

[0028] Regardless of the possibility of heat dissipation, encapsulating the protective device, e.g. the protective circuit board, can also serve to prevent non-destructive replacement and removal of the protective circuit board. In one embodiment, the batteries and the protective device can first be encapsulated or surrounded by a encapsulating compound, at least in part, and the resulting block is (subsequently) inserted into a separate protective housing. Alternatively, the batteries and the protective device can also first be inserted into a prefabricated housing and then encapsulated with the encapsulating compound inside the housing. Finally, there is also the possibility that the batteries and the protective device are encapsulated, at least in part, with the encapsulating compound directly beneath the formation of the protective housing, i.e. the hardened encapsulating compound already forms the protective housing.

[0029] It is also advisable to recess the battery unit's connection contacts (which are contacted with corresponding connection elements of the control electronics when the battery unit is inserted) into the protective housing. This reliably prevents the battery terminals from short-circuiting due to improper handling, e.g., if the battery unit is standing or lying on a conductive, flat surface, such as a steel table. A short circuit is also prevented if the battery unit comes into contact with other conductive components or tools.

[0030] The invention relates not only to the described lubricant dispenser, which is particularly intended and suitable for use in potentially explosive environments, but also to the described battery unit for such a lubricant dispenser. The battery unit is therefore also protected independently.

[0031] The invention also relates to a method for producing such a battery unit. During production, the protective device, e.g., the protective circuit board, is preferably encapsulated with a potting compound in or with the protective housing.

[0032] In a first method variant, a protective housing can first be provided, e.g., a first housing part. The current-limiting device and the individual battery cells, including power connections, can be inserted into this first housing part, which can, for example, have a cup-shaped design. The remaining cavity can then be at least partially filled with a potting compound. In this way, at least the protective device within the housing is at least partially filled with a potting compound. This can, for example, serve to encapsulate the relevant current-limiting element, e.g., the fuse on the circuit board, for the reasons described. Furthermore, the encapsulation prevents removal of the current-limiting device. After encapsulation, the housing can optionally and preferably be closed with a non-removable lid.

[0033] In a second process variant, the individual battery cells can first be connected to the current limiting device, e.g., to the current limiting circuit board. This arrangement can then be encapsulated, for example, by being inserted into a mold and encapsulated, so that a solid block is subsequently removed from the mold, which contains the battery cells and the protective device contacted with them. This pre-product can then be inserted into a protective housing. This variant, which can also be referred to as the "cage variant," has the advantage that relatively little plastic material is required and that delicate surfaces are possible. This is advantageous for later handling when changing the battery unit. The battery terminals can also be recessed in this embodiment, thus avoiding short circuits.The additional plastic housing acts as a protective casing, partially absorbing impact energy if the battery pack is dropped. Optionally, the cage material can be an elastomer, protecting the potting block inside the cage from damage. Alternatively, the cage material can also be made of a hard material.

[0034] Alternatively, it is possible to create the protective housing itself by encapsulating the batteries and the protective device, so that the protective housing is formed by the encapsulation compound without the use of a separate outer housing.

[0035] Within the scope of the invention, a separate battery unit is always provided, which is equipped with a current-limiting device, so that the battery unit can be safely replaced even in potentially explosive atmospheres. The lubricant dispenser can be designed such that the explosion-proof battery unit is integrated into the housing of the lubricant dispenser, so that the battery unit is located inside the housing of the lubricant dispenser.

[0036] Alternatively, the explosion-proof battery unit can also be used with a lubrication system, such as an explosion-proof lubrication system, via a plug or socket. This allows the battery unit to be replaced without opening the lubricator housing.

[0037] Finally, it is possible to connect the explosion-proof battery unit to the housing of the lubricant dispenser using a cable connection.

[0038] Furthermore, it is expedient not only to design the battery unit in the manner described to be explosion-proof, but also to implement the lubricant dispenser itself and the electronics installed therein in an explosion-proof manner. For this purpose, use can be made, for example, of a lubricant dispenser or the control electronics of the lubricant dispenser, as described in DE 10 2021 129 977 A1. The control electronics of the lubricant dispenser can therefore be designed such that the electronic circuit arrangement is divided into several circuit islands or has several circuit islands, with some or all of the circuit islands each being power-limited. For this purpose, one or more circuit islands can each be power-limited by at least one power-limiting resistor, e.g., a series resistor.Alternatively or additionally, one or more circuit islands, preferably those without power limitation, can each be equipped with a thermal fuse, which is mounted, for example, on the circuit board in the area of ​​the circuit island. Further details are described in DE 10 2021 129 977 A1.

[0039] The invention will be explained in more detail below with reference to drawings which merely represent exemplary embodiments.

[0040] Fig. 1 a lubricant dispenser in a highly simplified

[0041] Depiction,

[0042] Fig. 2 shows a battery unit according to the invention of a lubricant dispenser according to Fig. 1,

[0043] Fig. 3 shows a modified embodiment of a battery unit according to the invention,

[0044] Fig. 4 shows a manufacturing variant of the battery unit according to Fig. 3, Fig. 5 shows the manufacturing of a modified embodiment of a battery unit,

[0045] Fig. 6A, 6B two modified embodiments of the invention,

[0046] Fig. 7A, 7B further embodiments of the invention and

[0047] Fig. 8 shows another embodiment of the invention.

[0048] The figures show a lubricant dispenser intended and suitable for use in potentially explosive environments. The lubricant dispenser 1 has a lubricant reservoir 2 filled with lubricant. Furthermore, the lubricant dispenser has an electromechanical drive 7, e.g., an electric motor, which operates on at least one actuating element 4, e.g., a piston or a pump element, to dispense lubricant from the lubricant reservoir 2. In the illustrated embodiment, the actuating element is designed as a piston 4, which is arranged in the cartridge 2, specifically on a rotatable spindle 5. The lubricant cartridge 2 is connected to a drive 7 arranged in the housing 6, wherein this drive is designed as an electromechanical drive. In the exemplary embodiment, this is an electric motor 7, specifically a DC motor, e.g., a brushless DC motor.The motor 7 drives the spindle 5 and thus the piston 4, via which the lubricant is pressed out of the cartridge 2 via the lubricant outlet 3.

[0049] The structure and mode of operation of such a lubricant dispenser 1 are known. In the housing 6 of the lubricant dispenser 1, control electronics 9 for the electromechanical drive are also provided. Furthermore, at least one battery unit 8 is provided, which has a protective housing 10 (battery housing) and one or more batteries 11 (i.e., battery cells) arranged in the protective housing 10. According to the invention, the battery unit 8 is replaceable, i.e., it can be removed from the housing 6 and replaced with another battery unit. The two battery poles, i.e., the positive pole + and negative pole - of a battery unit 8 are contacted with the control electronics 9 for power supply. Fig. 1 shows a highly simplified embodiment in which the battery unit 8 is integrated into the housing 6 of the lubricant dispenser.To replace the battery unit 8, the housing 6 of the lubricant dispenser 1 is opened, the battery unit 8 is removed, and replaced with a new one. The + and - poles of the battery unit 8 are connected either directly or via connection contacts 13a, 13b of the battery unit to corresponding connection points 14a, 14b of the control electronics. These connection points 14a, 14b of the control electronics can be designed, for example, as spring contacts.

[0050] To enable safe replacement of the battery unit 8 in a potentially explosive environment, the battery unit 8 is equipped with a current-limiting protective device 12, which is arranged in the protective housing 10 of the battery unit 8 and is connected in series between at least one of the battery poles and a connection contact 13a of the battery unit 8. For this purpose, reference is made to Fig. 2, which shows an embodiment with two battery cells 11 connected in series. To operate the battery unit 8, the negative pole - of the first battery cell 11 and the positive pole + of the second battery cell 11 are contacted by the control electronics 9. However, the positive pole + of the second battery cell 11 is not contacted directly by the corresponding contact element 14a of the control electronics, but rather by interposing the protective device 12 according to the invention.In the exemplary embodiment, this is a protection board 12 equipped with a current limiter for the battery current. Furthermore, the protection board 12 can be equipped with the connection contact 13a, so that the positive pole of the battery cell 11 is connected in series with the connection contact 13a, with the current limiter interposed.

[0051] There are several options for designing the current limiter on the protective circuit board 12, which is only indicated in Fig. 2. One or more resistors can be provided for current limiting. Alternatively or additionally, the protective circuit board 12 can be equipped with one or more fuses. Finally, there is the alternative possibility of equipping the protective circuit board with current monitoring via a current measuring resistor and with a voltage monitoring module and a fuse. Details are not shown in the figures. The person skilled in the art can draw on the knowledge of current limiting that is generally known to him, which is integrated according to the invention into a battery unit 8 for a lubricant dispenser 1.

[0052] An alternative embodiment with three battery cells 11 is shown in Fig. 3. The three battery cells 11 are connected in series, so that a positive pole + of one cell and a negative pole - of another cell are used to make contact with the control electronics 9. In both cases, these poles +, - are connected to the protective circuit board 12, namely to connection contacts 13a, 13b on the circuit board 12, so that the two poles +, - are not directly contacted with the control electronics 9 or contact points 14a, 14b of the control electronics, but via the protective circuit board 12. However, only one of the poles + is connected to the connection contact 13a via the interposition of the current-limiting protective device, while the other pole - is directly electrically connected to the connection contact 13b.

[0053] It is always important that the battery unit 8 is designed in such a way that the current-limiting protective device 12 cannot be removed without destroying the battery unit 8 or at least damaging it to such an extent that it becomes unusable.

[0054] Fig. 4 shows a first manufacturing process variant. The protective housing 10 consists of several housing parts 15, 16. A first housing part 15 is provided, which can, for example, have a cup-shaped contour. The current-limiting circuit board 12 and the individual cells 11, including the power connections, are inserted into this housing part 15. The cavity is then filled with a potting compound, optionally not completely, but only to the extent that any current-limiting element arranged on the protective circuit board 12, e.g., a fuse, is potted. In principle, however, such potting can also be omitted. In this case, however, it is important that the housing 15 is subsequently sealed in a non-removable manner, e.g., with a cover 16.

[0055] Fig. 5 shows an alternative manufacturing variant in which the individual battery cells 11 are first connected to the protective circuit board 12. This unit is then inserted into a casting mold 20 and potted. This creates a solid block 10' containing the battery cells 11 and the protective circuit board 12, which are encased in the potting compound. The process can be carried out in such a way that this potting compound already forms the protective housing. Alternatively, the block 10' can then optionally be inserted into a housing, e.g., a plastic housing as the protective housing 10, so that a cage variant is realized. In this case, it is preferably provided that the battery poles +, - or the connection contacts 13a, 13b are arranged countersunk in the housing 10, so that a short circuit is avoided even when the battery unit is standing or lying on a conductive, flat geometry.

[0056] In addition to the explosion-proof design of the battery unit 8 shown in the figures, the control electronics 9 of the lubricant dispenser itself is preferably also designed so that the lubricant dispenser can be operated in potentially explosive atmospheres. For this purpose, a design according to DE 10 2021 129 977 A1 can be implemented. Details are not shown in the figures.

[0057] Figures 1 and 2 show a possible embodiment in which the battery unit 8 is inserted into the housing 2 of the lubricant dispenser 1 and is contacted with corresponding contact elements 14a, 14b (e.g. contact springs) of the control electronics 9, e.g. via spring elements or the like.

[0058] However, it is also possible to establish contact between the battery unit 8 and the control electronics 9 via plugs 17 and sockets 18. This is illustrated by way of example in Figures 6A and 6B, where in Figure 6A the plug 17 is provided on the control electronics 9 and the socket 18 is provided on the battery unit 8, while Figure 6B shows the reverse arrangement. In both cases, the battery unit 8 can be arranged outside the housing 6 of the lubricant dispenser.

[0059] Based on this, Figures 7A and 7B show a variant in which the connection of the battery unit 8 to the lubricant dispenser is made via a cable connection 19.

[0060] Finally, Fig. 8 shows an embodiment which, as in Figs. 6A, 6B, realizes a connection via plug 17 and socket 18, wherein the battery unit 8 is, however, arranged within the housing 6 of the lubricant dispenser 1.

[0061] The embodiment shown in Figures 7A and 7B with a cable connection 19 increases flexibility, as the battery unit 8 can be arranged outside the housing 6 of the lubricant dispenser 1. This is useful, for example, when lubrication systems are installed in environments where machine or system components are subject to strong vibration.

[0062] The figures show an example in which (only) one battery unit, i.e., one battery pack, is used. Alternatively, however, if necessary, multiple battery units can be used and connected (together), for example, to a control unit.

Claims

Patent claims:

1. Lubricant dispenser (1), in particular for use in potentially explosive environments, with at least one lubricant reservoir (2), an electromechanical drive (7) which operates on at least one actuating element (4) for dispensing lubricant from the lubricant reservoir, control electronics (9) for the drive and at least one battery unit which is replaceably connected or connectable to the control electronics (9), which battery unit has a protective housing (10) and one or more batteries (11) arranged in the protective housing (10), one or more battery poles (+, -) or one or more connection contacts (13a, b) connected to the battery pole(s) are or can be contacted with the control electronics (9), characterized in that a current-limiting protective device (12) is arranged in the protective housing (10), which current-limiting protective device is arranged between at least one battery pole (+, -) and at least one connection contact (13a,13b) of the battery unit (8) is connected in series., 2. Lubricant dispenser according to claim 1, characterized in that the protective device (12) is or has a protective circuit board connected to at least one battery pole, which is provided with a current limiter for the battery current, wherein the connection contact (13a,b) is arranged on the protective circuit board or is connected to the protective circuit board as a separate connection contact.

3. Lubricant dispenser according to claim 1 or 2, characterized in that the protective device (12) for current limitation has at least one resistor limiting the battery current.

4. Lubricant dispenser according to claim 3, characterized in that the protective device (12) for current limitation has a plurality of resistors connected in series and / or parallel and limiting the battery current.

5. Lubricant dispenser according to one of claims 1 to 4, characterized in that the protective device (12) has at least one fuse, e.g. a melting fuse, which is provided, e.g., in addition to one or more resistors.

6. Lubricant dispenser according to one of claims 1 to 5, characterized in that the protective device (12) has an electronic protective circuit which includes at least one current monitor and is preferably provided with multiple redundancy, e.g. on the protective circuit board.

7. Lubricant dispenser according to one of claims 1 to 6, characterized in that the protective device (12), e.g. the protective circuit board, is arranged in the protective housing (10) in such a way that it cannot be removed without destroying the battery unit (8).

8. Lubricant dispenser according to claim 7, characterized in that the protective housing (10) cannot be opened without causing damage.

9. Lubricant dispenser according to claim 8, characterized in that the protective housing (10) consists of several housing parts (15, 16), e.g. Housing halves or a housing part (15) and a cover (16), which are non-detachably connected to one another.

10. Lubricant dispenser according to claim 9, characterized in that the housing parts (15, 16) are connected to one another by a material fit, e.g., glued and / or welded, or that the housing parts are connected to one another by a form-fitting connection that cannot be removed without destruction, e.g., a clip connection.

11. Lubricant dispenser according to one of claims 7 to 10, characterized in that the protective device (12), e.g. the protective circuit board, is cast in or with the protective housing (10).

12. Lubricant dispenser according to one of claims 7 to 10, characterized in that the batteries (11) and the protective device (12) are at least partially encapsulated with a casting compound to form the protective housing (10).

13. Lubricant dispenser according to one of claims 7 to 10, characterized in that the batteries (11) and the protective device (12) are at least partially cast with a casting compound and then inserted into the protective housing.

14. Lubricant dispenser according to one of claims 1 to 12, characterized in that the connection contacts (13a, 13b) of the battery unit (8), with which the battery unit (8) can be contacted with the control electronics (9) for the drive (7), are arranged countersunk in the protective housing (10).

15. Battery unit for a lubricant dispenser according to one of claims 1 to 14, characterized in that a protective device (12) limiting the battery current is arranged in the protective housing (10) of the battery unit (8), which is connected in series between at least one battery pole and a connection contact (13a, b) of the battery unit.

16. A method for producing a battery unit according to claim 15, characterized in that the batteries and / or the protective device (12), e.g. the protective circuit board, is / are potted at least in regions with a potting compound 17. The method according to claim 16, characterized in that first the housing or at least a first housing part is provided and the batteries and the protective device are inserted into the first housing part and that subsequently at least the protective device is potted at least partially in the housing with a potting compound.

18. A method according to claim 16, characterized in that firstly the batteries and the protective device are at least partially encapsulated with a potting compound and that subsequently the encapsulated unit comprising the protective device and batteries is inserted into a housing, e.g. into the protective housing.

19. Method according to claim 16, characterized in that the batteries and the protective device are at least partially potted with a potting compound to form the protective housing, so that the cured potting compound forms the protective housing.

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